Peripheral nerve blocks for hip fractures in adults.

BACKGROUND: This review was published originally in 1999 and was updated in 2001, 2002, 2009, 2017, and 2020. Updating was deemed necessary due to the high incidence of hip fractures, the large number of official societies providing recommendations on this condition, the possibility that perioperative peripheral nerve blocks (PNBs) may improve patient outcomes, and the major role that PNBs may play in reducing preoperative and postoperative opioid use for analgesia. OBJECTIVES: To compare PNBs used as preoperative analgesia, as postoperative analgesia, or as a supplement to general anaesthesia versus no nerve block (or sham block) for adults with hip fracture. Outcomes were pain on movement at 30 minutes after block placement, acute confusional state, myocardial infarction, chest infection, death, time to first mobilization, and costs of an analgesic regimen for single-injection blocks. We undertook the update to look for new studies and to update the methods to reflect Cochrane standards. SEARCH METHODS: For the updated review, we searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 11), in the Cochrane Library; MEDLINE (Ovid SP, 1966 to November 2019); Embase (Ovid SP, 1974 to November 2019); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCO, 1982 to November 2019), as well as trial registers and reference lists of relevant articles. SELECTION CRITERIA: We included randomized controlled trials (RCTs) assessing use of PNBs compared with no nerve block (or sham block) as part of the care provided for adults 16 years of age and older with hip fracture.  DATA COLLECTION AND ANALYSIS: Two review authors independently screened new trials for inclusion, assessed trial quality using the Cochrane Risk of Bias-2 tool, and extracted data. When appropriate, we pooled results of outcome measures. We rated the certainty of evidence using the GRADE approach. MAIN RESULTS: We included 49 trials (3061 participants; 1553 randomized to PNBs and 1508 to no nerve block (or sham block)). For this update, we added 18 new trials. Trials were published from 1981 to 2020. Trialists followed participants for periods ranging from 5 minutes to 12 months. The average age of participants ranged from 59 to 89 years. People with dementia were often excluded from the included trials. Additional analgesia was available for all participants. Results of 11 trials with 503 participants show that PNBs reduced pain on movement within 30 minutes of block placement (standardized mean difference (SMD) -1.05, 95% confidence interval (CI) -1.25 to -0.86; equivalent to -2.5 on a scale from 0 to 10; high-certainty evidence). Effect size was proportionate to the concentration of local anaesthetic used (P = 0.0003). Based on 13 trials with 1072 participants, PNBs reduce the risk of acute confusional state (risk ratio (RR) 0.67, 95% CI 0.50 to 0.90; number needed to treat for an additional beneficial outcome (NNTB) 12, 95% CI 7 to 47; high-certainty evidence). For myocardial infarction, there were no events in one trial with 31 participants (RR not estimable; low-certainty evidence). From three trials with 131 participants, PNBs probably reduce the risk for chest infection (RR 0.41, 95% CI 0.19 to 0.89; NNTB 7, 95% CI 5 to 72; moderate-certainty evidence). Based on 11 trials with 617 participants, the effects of PNBs on mortality within six months are uncertain due to very serious imprecision (RR 0.87, 95% CI 0.47 to 1.60; low-certainty evidence). From three trials with 208 participants, PNBs likely reduce time to first mobilization (mean difference (MD) -10.80 hours, 95% CI -12.83 to -8.77 hours; moderate-certainty evidence). One trial with 75 participants indicated there may be a small reduction in the cost of analgesic drugs with a single-injection PNB (MD -4.40 euros, 95% CI -4.84 to -3.96 euros; low-certainty evidence). We identified 29 ongoing trials, of which 15 were first posted or at least were last updated after 1 January 2018.  AUTHORS' CONCLUSIONS: PNBs reduce pain on movement within 30 minutes after block placement, risk of acute confusional state, and probably also reduce the risk of chest infection and time to first mobilization. There may be a small reduction in the cost of analgesic drugs for single-injection PNB. We did not find a difference for myocardial infarction and mortality, but the numbers of participants included for these two outcomes were insufficient. Although randomized clinical trials may not be the best way to establish risks associated with an intervention, our review confirms low risks of permanent injury associated with PNBs, as found by others. Some trials are ongoing, but it is unclear whether any further RCTs should be registered, given the benefits found. Good-quality non-randomized trials with appropriate sample size may help to clarify the potential effects of PNBs on myocardial infarction and mortality.

Regional Analgesia Added to General Anesthesia Compared With General Anesthesia Plus Systemic Analgesia for Cardiac Surgery in Children: A Systematic Review and Meta-analysis of Randomized Clinical Trials.

BACKGROUND: The aim of this systematic review was to compare the effects of regional analgesic (RA) techniques with systemic analgesia on postoperative pain, nausea and vomiting, resources utilization, reoperation, death, and complications of the analgesic techniques in children undergoing cardiac surgery. METHODS: A search was done in May 2018 in PubMed, Embase, and the Cochrane Central Register of Controlled Trials for randomized controlled trials comparing RA techniques with systemic analgesia. Risks of bias of included trials were judged with the Cochrane tool. Data were analyzed with fixed- (I(2) < 25%) or random-effects models (I(2) ≥ 25%). The quality of evidence was graded according to the Grading of Recommendations Assessment, Development, and Evaluation working group scale. RESULTS: We included 14 randomized controlled trials with 605 participants (312 to RA and 293 to the comparator). RA reduces pain up to 24 hours after surgery. At 6-8 hours after surgery, the standardized mean difference was -0.81 (95% confidence interval [CI], -1.22 to -0.40; low-quality evidence). We did not find a difference for nausea and vomiting (risk ratio [RR], 0.89; 95% CI, 0.61-1.31; very low-quality evidence), duration of tracheal intubation (standardized mean difference, -0.18; 95% CI, -0.40 to 0.05; low-quality evidence), intensive care unit length of stay (mean difference, -0.10 hours; 95% CI, -1.31 to 1.12 hours; low-quality evidence), hospital length of stay (mean difference, -0.02 days; 95% CI, -1.16 to 1.12 days; low-quality evidence), reoperation (RR, 0.76; 95% CI, 0.17-3.28; low-quality evidence), death (RR, 0.50; 95% CI, 0.05-4.94; low-quality evidence), and respiratory depression (RR, 2.06; 95% CI, 0.20-21.68; very low-quality evidence). No trial reported signs of local anesthetic toxicity or lasting neurological or infectious complications related to the RA techniques. One trial reported 1 transient ipsilateral episode of diaphragmatic paralysis with intrapleural analgesia that resolved with cessation of local anesthetic administration. CONCLUSIONS: Compared to systemic analgesia, RA techniques reduce postoperative pain up to 24 hours in children undergoing cardiac surgery. Currently, there is no evidence that RA for pediatric cardiac surgery has any impact on major morbidity and mortality. These results should be interpreted cautiously because they represent a meta-analysis of small and heterogeneous studies. Further studies are needed.

Epidural analgesia for adults undergoing cardiac surgery with or without cardiopulmonary bypass.

BACKGROUND: General anaesthesia combined with epidural analgesia may have a beneficial effect on clinical outcomes. However, use of epidural analgesia for cardiac surgery is controversial due to a theoretical increased risk of epidural haematoma associated with systemic heparinization. This review was published in 2013, and it was updated in 2019. OBJECTIVES: To determine the impact of perioperative epidural analgesia in adults undergoing cardiac surgery, with or without cardiopulmonary bypass, on perioperative mortality and cardiac, pulmonary, or neurological morbidity. SEARCH METHODS: We searched CENTRAL, MEDLINE, and Embase in November 2018, and two trial registers up to February 2019, together with references and relevant conference abstracts. SELECTION CRITERIA: We included all randomized controlled trials (RCTs) including adults undergoing any type of cardiac surgery under general anaesthesia and comparing epidural analgesia versus another modality of postoperative pain treatment. The primary outcome was mortality. DATA COLLECTION AND ANALYSIS: We used standard methodological procedures as expected by Cochrane. MAIN RESULTS: We included 69 trials with 4860 participants: 2404 given epidural analgesia and 2456 receiving comparators (systemic analgesia, peripheral nerve block, intrapleural analgesia, or wound infiltration). The mean (or median) age of participants varied between 43.5 years and 74.6 years. Surgeries performed were coronary artery bypass grafting or valvular procedures and surgeries for congenital heart disease. We judged that no trials were at low risk of bias for all domains, and that all trials were at unclear/high risk of bias for blinding of participants and personnel taking care of study participants.Epidural analgesia versus systemic analgesiaTrials show there may be no difference in mortality at 0 to 30 days (risk difference (RD) 0.00, 95% confidence interval (CI) -0.01 to 0.01; 38 trials with 3418 participants; low-quality evidence), and there may be a reduction in myocardial infarction at 0 to 30 days (RD -0.01, 95% CI -0.02 to 0.00; 26 trials with 2713 participants; low-quality evidence). Epidural analgesia may reduce the risk of 0 to 30 days respiratory depression (RD -0.03, 95% CI -0.05 to -0.01; 21 trials with 1736 participants; low-quality evidence). There is probably little or no difference in risk of pneumonia at 0 to 30 days (RD -0.03, 95% CI -0.07 to 0.01; 10 trials with 1107 participants; moderate-quality evidence), and epidural analgesia probably reduces the risk of atrial fibrillation or atrial flutter at 0 to 2 weeks (RD -0.06, 95% CI -0.10 to -0.01; 18 trials with 2431 participants; moderate-quality evidence). There may be no difference in cerebrovascular accidents at 0 to 30 days (RD -0.00, 95% CI -0.01 to 0.01; 18 trials with 2232 participants; very low-quality evidence), and none of the included trials reported any epidural haematoma events at 0 to 30 days (53 trials with 3982 participants; low-quality evidence). Epidural analgesia probably reduces the duration of tracheal intubation by the equivalent of 2.4 hours (standardized mean difference (SMD) -0.78, 95% CI -1.01 to -0.55; 40 trials with 3353 participants; moderate-quality evidence). Epidural analgesia reduces pain at rest and on movement up to 72 hours after surgery. At six to eight hours, researchers noted a reduction in pain, equivalent to a reduction of 1 point on a 0 to 10 pain scale (SMD -1.35, 95% CI -1.98 to -0.72; 10 trials with 502 participants; moderate-quality evidence). Epidural analgesia may increase risk of hypotension (RD 0.21, 95% CI 0.09 to 0.33; 17 trials with 870 participants; low-quality evidence) but may make little or no difference in the need for infusion of inotropics or vasopressors (RD 0.00, 95% CI -0.06 to 0.07; 23 trials with 1821 participants; low-quality evidence).Epidural analgesia versus other comparatorsFewer studies compared epidural analgesia versus peripheral nerve blocks (four studies), intrapleural analgesia (one study), and wound infiltration (one study). Investigators provided no data for pulmonary complications, atrial fibrillation or flutter, or for any of the comparisons. When reported, other outcomes for these comparisons (mortality, myocardial infarction, neurological complications, duration of tracheal intubation, pain, and haemodynamic support) were uncertain due to the small numbers of trials and participants. AUTHORS' CONCLUSIONS: Compared with systemic analgesia, epidural analgesia may reduce the risk of myocardial infarction, respiratory depression, and atrial fibrillation/atrial flutter, as well as the duration of tracheal intubation and pain, in adults undergoing cardiac surgery. There may be little or no difference in mortality, pneumonia, and epidural haematoma, and effects on cerebrovascular accident are uncertain. Evidence is insufficient to show the effects of epidural analgesia compared with peripheral nerve blocks, intrapleural analgesia, or wound infiltration.

The use of ultrasound guidance for perioperative neuraxial and peripheral nerve blocks in children.

BACKGROUND: The use of ultrasound guidance for regional anaesthesia has become popular over the past two decades. However, it is not recognized by all experts as an essential tool, perhaps because it is unclear whether ultrasound reduces the risk of severe neurological complications, and the cost of an ultrasound machine (USD 22,000) is substantially higher than the cost of other tools. This review was published in 2016 and updated in 2019. OBJECTIVES: To determine whether ultrasound guidance offers any clinical advantage when neuraxial and peripheral nerve blocks are performed in children in terms of decreasing failure rate or the rate of complications. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, and two trial registers up to March 2018 together with reference checking to identify additional studies and contacted study authors to obtain additional trial information. SELECTION CRITERIA: We included all parallel randomized controlled trials that evaluated the effects of ultrasound guidance used when a regional blockade technique was performed in children. We included studies performed in children (≤ 18 years of age) undergoing any type of surgical procedure (open or laparoscopic), for which a neuraxial (spinal, epidural, caudal, or combined spinal and epidural) or peripheral nerve block (any peripheral nerve block including fascial (fascia iliaca, transversus abdominis plane, rectus sheath blocks) or perivascular blocks), for surgical anaesthesia (alone or in combination with general anaesthesia) or for postoperative analgesia, was performed with ultrasound guidance. We excluded studies in which regional blockade was used to treat chronic pain.We included studies in which ultrasound guidance was used to perform the technique in real time (in-plane or out-of-plane), as pre-scanning before the procedure or to evaluate the spread of the local anaesthetic so the position of the needle could be adjusted or the block complemented. For control groups, any other technique used to perform the block including landmarks, loss of resistance (air or fluid), click, paraesthesia, nerve stimulator, transarterial, or infiltration was accepted. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane. Our primary outcomes were failed blocks, pain scores at one hour after surgery, and block duration. Secondary outcomes included time to perform the block, number of needle passes, and minor and major complications. We used GRADE to assess the quality of evidence for each outcome. MAIN RESULTS: We included 33 trials with a total of 2293 participants from 0.9 to 12 (mean or median) years of age. Most trials were at low risk of selection, detection, attrition, and reporting bias, however the lack of blinding of participants and personnel caring for participants resulted in 25 trials being judged as at high or unclear risk of bias. We identified five ongoing trials.Ultrasound guidance probably reduces the risk of failed block (risk difference (RD) -0.16, 95% confidence interval (CI) -0.25 to -0.07; 22 trials; 1789 participants; moderate-quality evidence). When ultrasound guidance was used, there was a small to moderate reduction in pain one hour after surgery, equivalent to a reduction of 1.3 points on the revised Bieri FACES pain scale (scale; 0 = no pain, 10 = maximal pain) (standardized mean difference (SMD) -0.41, 95% CI -0.74 to -0.07 (medium effect size); 15 trials; 982 participants; moderate-quality evidence). Ultrasound guidance increases block duration by the equivalent of 42 minutes (SMD 1.24, 95% CI 0.72 to 1.75; 10 trials; 460 participants; high-quality evidence).There is probably little or no difference in the time taken to perform the block (SMD -0.46, 95% CI -1.06 to 0.13; 9 trials; 680 participants; moderate-quality evidence). It is uncertain whether the number of needle passes required is reduced with the use of ultrasound guidance (SMD -0.63, 95% CI -1.08 to -0.18; 3 trials; 256 participants; very low-quality evidence).There were no occurrences of major complications in either the intervention or control arms of the trials (cardiac arrest from local anaesthetic toxicity (22 trials; 1576 participants; moderate-quality evidence); lasting neurological injury (19 trials; 1250 participants; low-quality evidence)).There may be little of no difference in the risk of bloody puncture (RD -0.02, 95% CI -0.05 to 0.00; 13 trials; 896 participants; low-quality evidence) or transient neurological injury (RD -0.00, 95% CI -0.01 to 0.01; 18 trials; 1230 participants; low-quality evidence). There were no occurrences of seizure from local anaesthetic toxicity (22 trials; 1576 participants; moderate-quality evidence) or block infections without neurological injury (18 trials; 1238 participants; low-quality evidence). AUTHORS' CONCLUSIONS: Ultrasound guidance for regional blockade in children probably decreases the risk of failed block. It increases the duration of the block and probably decreases pain scores at one hour after surgery. There may be little or no difference in the risks of some minor complications. The five ongoing studies may alter the conclusions of the review once published and assessed.

Postoperative epidural analgesia versus systemic analgesia for thoraco-lumbar spine surgery in children.

BACKGROUND: Spine surgery may be associated with severe acute postoperative pain. Compared with systemic analgesia alone, epidural analgesia may offer better pain control. However, epidural analgesia has sometimes been associated with rare but serious complications. Therefore, it is critical to quantify the real benefits of epidural analgesia over other modes of pain treatment. OBJECTIVES: To assess the effectiveness and safety of epidural analgesia compared with systemic analgesia for acute postoperative pain control after thoraco-lumbar spine surgery in children. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase and Cumulative Index to Nursing and Allied Health Literature on 14 November 2018, together with the references lists of related reviews and retained trials, and two trials registers. SELECTION CRITERIA: We included all randomized controlled trials performed in children undergoing any type of thoraco-lumbar spine surgery comparing epidural analgesia with systemic analgesia for postoperative pain. We applied no language or publication status restriction. DATA COLLECTION AND ANALYSIS: We assessed risk of bias of included trials using the Cochrane tool. We analysed data using random-effects models. We rated the quality of the evidence according to the GRADE scale. MAIN RESULTS: We included 11 trials (559 participants) in the review, and seven trials (249 participants) in the analysis: 140 participants received epidural analgesia and 109 received systemic analgesia.Most studies included adolescents. Three trials included in the analysis contained some participants older than 18 years. The types of surgery were posterior spinal fusion for idiopathic scoliosis (nine trials), anterior correction for idiopathic scoliosis (one trial), or selective dorsal rhizotomy in children with cerebral palsy (one trial). The mean numbers of vertebrae operated on were between nine and 14.5 and the mean numbers of spinal levels were between three and four and a half. The length of surgery varied between three and six and a half hours.Compared with systemic analgesia, epidural analgesia reduced pain at rest at all time points. At six to eight hours, the mean pain score on a 0 to 10 scale with systemic analgesia was 3.1 (standard deviation 0.7) and with epidural analgesia was -1.32 points (95% confidence interval (CI) -1.83 to -0.82; 4 studies, 116 participants; moderate-quality evidence). At 72 hours, the mean pain score with epidural analgesia was equivalent to a -0.8 point reduction on a 0 to 10 scale (standardized mean difference (SMD) -0.65, 95% CI -1.19 to -0.10; 5 studies, 157 participants; moderate-quality evidence).Return of gastrointestinal functionThere was no difference for nausea and vomiting between groups (risk ratio (RR) 0.87, 95% CI 0.58 to 1.30; 6 studies, 215 participants; low-quality evidence). One study found epidural analgesia with local anaesthetics may have increased the number of participants who had their first flatus within 48 hours (RR 1.63, 95% CI 1.08 to 2.47; 30 participants; very low-quality evidence). Two studies found epidural analgesia with local anaesthetics may have increased the number of participants in whom first bowel movement occurred within 48 hours (RR 11.52, 95% CI 2.36 to 56.26; 60 participants; low-quality evidence). It was uncertain whether epidural analgesia reduced the time to first bowel movement (MD 0.09 days, 95% CI -0.32 to 0.50; 1 study, 60 participants; very low-quality evidence) and time to first liquid ingestion following epidural infusion of an opioid alone or a local anaesthetic plus an opioid (mean difference (MD) -5.02 hours, 95% CI -13.15 to 3.10; 2 studies, 56 participants; very low-quality evidence). Epidural analgesia with local anaesthetics may have increased the risk of having first solid food ingestion within 48 hours (RR 7.00, 95% CI 1.91 to 25.62; 1 study, 30 participants; very low-quality evidence).Secondary outcomesIt was uncertain whether there was a difference in time to ambulate (MD 0.08 days, 95% CI -0.24 to 0.39; 1 study, 60 participants; very low-quality evidence) and hospital length of stay (MD -0.29 days, 95% CI -0.69 to 0.10; 2 studies, 89 participants; very low-quality evidence). Two studies found participants were more satisfied when treated with epidural analgesia (MD 1.62 on a scale from 0 to 10, 95% CI 1.26 to 1.97; 60 participants; very low-quality evidence). It was unclear whether there was a difference in parent satisfaction for epidural analgesia with an opioid alone (MD 0.60, 95% CI -0.81 to 2.01; 1 trial, 27 participants; very low-quality evidence).ComplicationsIt was uncertain whether there was a difference in the risk of complications such as: respiratory depression (risk difference (RD) -0.05, 95% CI -0.16 to 0.05; 4 studies, 126 participants; very low-quality evidence); wound infection (RD 0.01, 95% CI -0.05 to 0.08; 2 trials, 93 participants; very low-quality evidence); epidural abscess (RD 0, 95% CI -0.05 to 0.05; 3 trials, 120 participants; very low-quality evidence); and neurological complications (RD 0.01, 95% CI -0.04 to 0.06; 4 studies, 151 participants; very low-quality evidence). AUTHORS' CONCLUSIONS: There is moderate- and low-quality evidence that there may be a small additional reduction in pain up to 72 hours after surgery with epidural analgesia compared with systemic analgesia. Two very small studies showed epidural analgesia with local anaesthetic alone may accelerate the return of gastrointestinal function. The safety of this technique in children undergoing thoraco-lumbar surgery is uncertain due to the very low-quality of the evidence. The study in 'Studies awaiting classification' may alter the conclusions of the review once assessed.

Peripheral Nerve Blocks for Hip Fractures: A Cochrane Review.

BACKGROUND: This review focuses on the use of peripheral nerve blocks as preoperative analgesia, as postoperative analgesia, or as a supplement to general anesthesia for hip fracture surgery and tries to determine if they offer any benefit in terms of pain on movement at 30 minutes after block placement, acute confusional state, myocardial infarction/ischemia, pneumonia, mortality, time to first mobilization, and cost of analgesic. METHODS: Trials were identified by computerized searches of Cochrane Central Register of Controlled Trials (2016, Issue 8), MEDLINE (Ovid SP, 1966 to 2016 August week 1), Embase (Ovid SP, 1988 to 2016 August week 1), and the Cumulative Index to Nursing and Allied Health Literature (EBSCO, 1982 to 2016 August week 1), trials registers, and reference lists of relevant articles. Randomized controlled trials involving the use of nerve blocks as part of the care for hip fractures in adults aged 16 years and older were included. The quality of the studies was rated according to the Cochrane tool. Two authors independently extracted the data. The quality of evidence was judged according to the Grading of Recommendations, Assessment, Development, and Evaluations Working Group scale. RESULTS: Based on 8 trials with 373 participants, peripheral nerve blocks reduced pain on movement within 30 minutes of block placement: standardized mean difference, -1.41 (95% confidence interval [CI], -2.14 to -0.67; equivalent to -3.4 on a scale from 0 to 10; I statistic = 90%; high quality of evidence). The effect size was proportional to the concentration of local anesthetic used (P < .00001). Based on 7 trials with 676 participants, no difference was found in the risk of acute confusional state: risk ratio, 0.69 (95% CI, 0.38-1.27; I statistic = 48%; very low quality of evidence). Based on 3 trials with 131 participants, the risk for pneumonia was decreased: risk ratio, 0.41 (95% CI, 0.19-0.89; I statistic = 3%; number needed-to-treat for additional beneficial outcome, 7 [95% CI, 5-72]; moderate quality of evidence). No difference was found for the risk of myocardial ischemia or death within 6 months but the number of participants included was well below the optimum information size for these 2 outcomes. Based on 2 trials with 155 participants, peripheral nerve blocks also reduced the time to first mobilization after surgery: mean difference, -11.25 hours (95% CI, -14.34 to -8.15 hours; I statistic = 52%; moderate quality of evidence). From 1 trial with 75 participants, the cost of analgesic drugs when used as a single-shot block was lower: standardized mean difference, -3.48 (95% CI, -4.23 to -2.74; moderate quality of evidence). CONCLUSIONS: There is high-quality evidence that regional blockade reduces pain on movement within 30 minutes after block placement. There is moderate quality of evidence for a decreased risk of pneumonia, reduced time to first mobilization, and reduced cost of analgesic regimen (single-shot blocks).

Intraoperative use of low volume ventilation to decrease postoperative mortality, mechanical ventilation, lengths of stay and lung injury in adults without acute lung injury.

BACKGROUND: Since the 2000s, there has been a trend towards decreasing tidal volumes for positive pressure ventilation during surgery. This an update of a review first published in 2015, trying to determine if lower tidal volumes are beneficial or harmful for patients. OBJECTIVES: To assess the benefit of intraoperative use of low tidal volume ventilation (less than 10 mL/kg of predicted body weight) compared with high tidal volumes (10 mL/kg or greater) to decrease postoperative complications in adults without acute lung injury. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 5), MEDLINE (OvidSP) (from 1946 to 19 May 2017), Embase (OvidSP) (from 1974 to 19 May 2017) and six trial registries. We screened the reference lists of all studies retained and of recent meta-analysis related to the topic during data extraction. We also screened conference proceedings of anaesthesiology societies, published in two major anaesthesiology journals. The search was rerun 3 January 2018. SELECTION CRITERIA: We included all parallel randomized controlled trials (RCTs) that evaluated the effect of low tidal volumes (defined as less than 10 mL/kg) on any of our selected outcomes in adults undergoing any type of surgery. We did not retain studies with participants requiring one-lung ventilation. DATA COLLECTION AND ANALYSIS: Two authors independently assessed the quality of the retained studies with the Cochrane 'Risk of bias' tool. We analysed data with both fixed-effect (I2 statistic less than 25%) or random-effects (I2 statistic greater than 25%) models based on the degree of heterogeneity. When there was an effect, we calculated a number needed to treat for an additional beneficial outcome (NNTB) using the odds ratio. When there was no effect, we calculated the optimum information size. MAIN RESULTS: We included seven new RCTs (536 participants) in the update.In total, we included 19 studies in the review (776 participants in the low tidal volume group and 772 in the high volume group). There are four studies awaiting classification and three are ongoing. All included studies were at some risk of bias. Participants were scheduled for abdominal surgery, heart surgery, pulmonary thromboendarterectomy, spinal surgery and knee surgery. Low tidal volumes used in the studies varied from 6 mL/kg to 8.1 mL/kg while high tidal volumes varied from 10 mL/kg to 12 mL/kg.Based on 12 studies including 1207 participants, the effects of low volume ventilation on 0- to 30-day mortality were uncertain (risk ratio (RR) 0.80, 95% confidence interval (CI) 0.42 to 1.53; I2 = 0%; low-quality evidence). Based on seven studies including 778 participants, lower tidal volumes probably reduced postoperative pneumonia (RR 0.45, 95% CI 0.25 to 0.82; I2 = 0%; moderate-quality evidence; NNTB 24, 95% CI 16 to 160), and it probably reduced the need for non-invasive postoperative ventilatory support based on three studies including 506 participants (RR 0.31, 95% CI 0.15 to 0.64; moderate-quality evidence; NNTB 13, 95% CI 11 to 24). Based on 11 studies including 957 participants, low tidal volumes during surgery probably decreased the need for postoperative invasive ventilatory support (RR 0.33, 95% CI 0.14 to 0.77; I2 = 0%; NNTB 39, 95% CI 30 to 166; moderate-quality evidence). Based on five studies including 898 participants, there may be little or no difference in the intensive care unit length of stay (standardized mean difference (SMD) -0.06, 95% CI -0.22 to 0.10; I2 = 33%; low-quality evidence). Based on 14 studies including 1297 participants, low tidal volumes may have reduced hospital length of stay by about 0.8 days (SMD -0.15, 95% CI -0.29 to 0.00; I2 = 27%; low-quality evidence). Based on five studies including 708 participants, the effects of low volume ventilation on barotrauma (pneumothorax) were uncertain (RR 1.77, 95% CI 0.52 to 5.99; I2 = 0%; very low-quality evidence). AUTHORS' CONCLUSIONS: We found moderate-quality evidence that low tidal volumes (defined as less than 10 mL/kg) decreases pneumonia and the need for postoperative ventilatory support (invasive and non-invasive). We found no difference in the risk of barotrauma (pneumothorax), but the number of participants included does not allow us to make definitive statement on this. The four studies in 'Studies awaiting classification' may alter the conclusions of the review once assessed.

The Use of Ultrasound Guidance for Perioperative Neuraxial and Peripheral Nerve Blocks in Children: A Cochrane Review.

BACKGROUND: Objectives were to determine whether the use of ultrasound guidance offers any clinical advantage in the performance of neuraxial or peripheral nerve blocks in children in terms of increasing the success rate or decreasing the rate of complications. METHODS: We searched the following databases to March 2015: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OvidSP), EMBASE (OvidSP), and Scopus (to January 2015). We included all parallel randomized controlled trials that evaluated the effect of ultrasound guidance to perform a regional blockade technique in children. We assessed the selected studies for risk of bias with the Cochrane collaboration tool. We graded the level of evidence for each outcome according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group scale. RESULTS: We included 20 studies (1241 participants). Ultrasound guidance increases the success rate by decreasing the occurrence of a failed block: risk difference -0.11 (95% confidence interval [CI], -0.17 to -0.05); I 64%; number needed for additional beneficial outcome for peripheral nerve blocks 6 (95% CI, 5-8). The younger the child, the greater the benefit. From 8 studies (414 participants), pain scores at 1 hour in the postanesthesia care unit were reduced when ultrasound guidance was used; however, the clinical relevance of the difference was unclear (equivalent to -0.2 on a scale from 0 to 10). From 8 studies (358 participants), block duration was longer when ultrasound guidance was used: standardized mean difference (SMD) 1.21 (95% CI, 0.76-1.65: I 73%; equivalent to 62 minutes). Here again, younger children benefited the most from ultrasound guidance. Time to perform the procedure was reduced when ultrasound guidance was used for prescanning before a neuraxial block (SMD -1.97; 95% CI, -2.41 to -1.54; I 0%; equivalent to 2.4 minutes) or as an out-of-plane technique (SMD -0.68; 95% CI, -0.96 to -0.40; I 0%; equivalent to 94 seconds). From 2 studies (122 participants), ultrasound guidance reduced the number of needle passes required to perform the block: SMD -0.90 (95% CI, -1.27 to -0.52; I 0%; equivalent to 0.6 needle pass per participant). From 2 studies (204 participants), we could not demonstrate a difference in the incidence of bloody puncture when ultrasound guidance was used for neuraxial blockade, but we found that the number of participants was well below the optimal information size (risk difference -0.07, 95% CI, -0.19 to 0.04). No major complications were reported for any of the 1241 participants. We rated the quality of evidence as high for success, pain scores at 1 hour, block duration, time to perform the block, and number of needle passes. We rated the quality of evidence as low for bloody punctures. CONCLUSIONS: Ultrasound guidance seems advantageous, particularly in young children, for whom it improves the success rate and increases block duration. Additional data are required before conclusions can be drawn on the effect of ultrasound guidance in reducing the rate of bloody puncture.

Nerve blocks or no nerve blocks for pain control after elective hip replacement (arthroplasty) surgery in adults.

BACKGROUND: It is estimated that over 300,000 total hip replacements are performed each year in the USA. For European countries, the number of hip replacement procedures per 100,000 people performed in 2007 varied from less than 50 to over 250. To facilitate postoperative rehabilitation, pain must be adequately treated. Peripheral nerve blocks and neuraxial blocks have been proposed to replace or supplement systemic analgesia. OBJECTIVES: We aimed to compare the relative effects (benefits and harms) of the different nerve blocks that may be used to relieve pain after elective hip replacement in adults. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, Issue 12, 2016), MEDLINE (Ovid SP) (1946 to December Week 49, 2016), Embase (Ovid SP) (1980 to December week 49, 2016), CINAHL (EBSCO host) (1982 to 6 December 2016), ISI Web of Science (1973 to 6 December 2016), Scopus (from inception to December 2016), trials registers, and relevant web sites. SELECTION CRITERIA: We included all randomized controlled trials (RCTs) performed in adults undergoing elective primary hip replacement and comparing peripheral nerve blocks to any other pain treatment modality. We applied no language or publication status restrictions. DATA COLLECTION AND ANALYSIS: Data were extracted independently by two review authors. We contacted study authors. MAIN RESULTS: We included 51 RCTs with 2793 participants; of these 45 RCTs (2491 participants: peripheral nerve block = 1288; comparators = 1203) were included in meta-analyses. There are 11 ongoing studies and three awaiting classification.Compared to systemic analgesia alone, peripheral nerve blocks reduced: pain at rest on arrival in the postoperative care unit (SMD -1.12, 95% CI -1.67 to -0.56; 9 trials, 429 participants; equivalent to 3.2 on 0 to 10 scale; moderate-quality evidence); risk of acute confusional status: risk ratio (RR) 0.10 95% CI 0.02 to 0.54; 1 trial, 225 participants; number needed to treat for additional benefit (NNTB) 12, 95% CI 11 to 22; very low-quality evidence); pruritus (RR 0.16, 95% CI 0.04 to 0.70; 2 trials, 259 participants for continuous peripheral nerve blocks; NNTB 4 (95% CI 4 to 8); very low-quality evidence); hospital length of stay (SMD -0.75, 95% CI -1.02 to -0.48; very low-quality evidence; 2 trials, 249 participants; equivalent to 0.75 day). Participant satisfaction increased (SMD 0.67, 95% CI 0.45 to 0.89; low-quality evidence; 5 trials, 363 participants; equivalent to 2.4 on 0 to 10 scale). We did not find a difference for the number of participants walking on postoperative day one (very low-quality evidence). Two nerve block-related complications were reported: one local haematoma and one delayed persistent paresis.Compared to neuraxial blocks, peripheral nerve blocks reduced the risk of pruritus (RR 0.33, 95% CI 0.19 to 0.58; 6 trials, 299 participants; moderate-quality evidence; NNTB 6 (95% CI 5 to 9). We did not find a difference for pain at rest on arrival in the postoperative care unit (moderate-quality evidence); number of nerve block-related complications (low-quality evidence); acute confusional status (very low-quality evidence); hospital length of stay (low quality-evidence); time to first walk (low-quality evidence); or participant satisfaction (high-quality evidence).We found that peripheral nerve blocks provide better pain control compared to systemic analgesia with no major differences between peripheral nerve blocks and neuraxial blocks. We also found that peripheral nerve blocks may be associated with reduced risk of postoperative acute confusional state and a modest reduction in hospital length of stay that could be meaningful in terms of cost reduction considering the increasing numbers of procedures performed annually. AUTHORS' CONCLUSIONS: Compared to systemic analgesia alone, there is moderate-quality evidence that peripheral nerve blocks reduce postoperative pain, low-quality evidence that patient satisfaction is increased and very low-quality evidence for reductions in acute confusional status, pruritus and hospital length of stay .We found moderate-quality evidence that peripheral nerve blocks reduce pruritus compared with neuraxial blocks.The 11 ongoing studies, once completed, and the three studies awaiting classification may alter the conclusions of the review once assessed.

Peripheral nerve blocks for hip fractures.

BACKGROUND: Various nerve blocks with local anaesthetic agents have been used to reduce pain after hip fracture and subsequent surgery. This review was published originally in 1999 and was updated in 2001, 2002, 2009 and 2017. OBJECTIVES: This review focuses on the use of peripheral nerves blocks as preoperative analgesia, as postoperative analgesia or as a supplement to general anaesthesia for hip fracture surgery. We undertook the update to look for new studies and to update the methods to reflect Cochrane standards. SEARCH METHODS: For the updated review, we searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 8), MEDLINE (Ovid SP, 1966 to August week 1 2016), Embase (Ovid SP, 1988 to 2016 August week 1) and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (EBSCO, 1982 to August week 1 2016), as well as trial registers and reference lists of relevant articles. SELECTION CRITERIA: We included randomized controlled trials (RCTs) involving use of nerve blocks as part of the care provided for adults aged 16 years and older with hip fracture. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed new trials for inclusion, determined trial quality using the Cochrane tool and extracted data. When appropriate, we pooled results of outcome measures. We rated the quality of evidence according to the GRADE Working Group approach. MAIN RESULTS: We included 31 trials (1760 participants; 897 randomized to peripheral nerve blocks and 863 to no regional blockade). Results of eight trials with 373 participants show that peripheral nerve blocks reduced pain on movement within 30 minutes of block placement (standardized mean difference (SMD) -1.41, 95% confidence interval (CI) -2.14 to -0.67; equivalent to -3.4 on a scale from 0 to 10; I2 = 90%; high quality of evidence). Effect size was proportionate to the concentration of local anaesthetic used (P < 0.00001). Based on seven trials with 676 participants, we did not find a difference in the risk of acute confusional state (risk ratio (RR) 0.69, 95% CI 0.38 to 1.27; I2 = 48%; very low quality of evidence). Three trials with 131 participants reported decreased risk for pneumonia (RR 0.41, 95% CI 0.19 to 0.89; I2 = 3%; number needed to treat for an additional beneficial outcome (NNTB) 7, 95% CI 5 to 72; moderate quality of evidence). We did not find a difference in risk of myocardial ischaemia or death within six months, but the number of participants included was well below the optimal information size for these two outcomes. Two trials with 155 participants reported that peripheral nerve blocks also reduced time to first mobilization after surgery (mean difference -11.25 hours, 95% CI -14.34 to -8.15 hours; I2 = 52%; moderate quality of evidence). One trial with 75 participants indicated that the cost of analgesic drugs was lower when they were given as a single shot block (SMD -3.48, 95% CI -4.23 to -2.74; moderate quality of evidence). AUTHORS' CONCLUSIONS: High-quality evidence shows that regional blockade reduces pain on movement within 30 minutes after block placement. Moderate-quality evidence shows reduced risk for pneumonia, decreased time to first mobilization and cost reduction of the analgesic regimen (single shot blocks).

Epidural Local Anesthetics Versus Opioid-Based Analgesic Regimens for Postoperative Gastrointestinal Paralysis, Vomiting, and Pain After Abdominal Surgery: A Cochrane Review.

BACKGROUND: The aim of this review was to compare the effects of postoperative epidural analgesia with local anesthetics to postoperative systemic or epidural opioids in terms of return of gastrointestinal transit, postoperative pain control, postoperative vomiting, incidence of gastrointestinal anastomotic leak, hospital length of stay, and cost after abdominal surgery. METHODS: Trials were identified by computerized searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 12), Medical Literature Analysis and Retrieval System Online (MEDLINE) (from 1950 to December, 2014) and Excerpta Medica dataBASE (EMBASE) (from 1974 to December 2014) and by checking the reference lists of trials retained. We included parallel randomized controlled trials comparing the effects of postoperative epidural local anesthetic with regimens based on systemic or epidural opioids. The quality of the studies was rated according to the Cochrane tool. Two authors independently extracted data. We judged the quality of evidence according to the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) working group scale. RESULTS: Based on 22 trials including 1138 participants, an epidural containing a local anesthetic will decrease the time required for return of gastrointestinal transit as measured by time required to observe the first flatus after an abdominal surgery standardized mean difference (SMD) -1.28 (95% confidence interval [CI], -1.71 to -0.86; high quality of evidence; equivalent to 17.5 hours). The effect is proportional to the concentration of local anesthetic used. Based on 28 trials including 1559 participants, we also found a decrease in time to first feces (stool): SMD -0.67 (95% CI, -0.86 to -0.47; low quality of evidence; equivalent to 22 hours). Based on 35 trials including 2731 participants, pain on movement at 24 hours after surgery is also reduced: SMD -0.89 (95% CI, -1.08 to -0.70; moderate quality of evidence; equivalent to 2.5 on a scale from 0 to 10). Based on 22 trials including 1154 participants, we did not find a difference in the incidence of vomiting within 24 hours: risk ratio 0.84 (95% CI, 0.57-1.23); low quality of evidence. Based on 17 trials including 848 participants we did not find a difference in the incidence of gastrointestinal anastomotic leak: risk ratio 0.74 (95% CI, 0.41-1.32; low quality of evidence). Based on 30 trials including 2598 participants, epidural analgesia reduces length of hospital stay for an open surgery: SMD -0.20 (95% CI, -0.35 to -0.04; very low quality of evidence; equivalent to 1 day). Data on cost were very limited. CONCLUSIONS: An epidural containing a local anesthetic, with or without the addition of an opioid, accelerates the return of the gastrointestinal transit (high quality of evidence). An epidural containing a local anesthetic with an opioid decreases pain after an abdominal surgery (moderate quality of evidence). An epidural containing a local anesthetic does not affect the incidence of vomiting or anastomotic leak (low quality of evidence). For an open surgery, an epidural containing a local anesthetic would reduce the length of hospital stay (very low quality of evidence).

Epidural pain relief versus systemic opioid-based pain relief for abdominal aortic surgery.

BACKGROUND: Epidural analgesia offers greater pain relief compared to systemic opioid-based medications, but its effect on morbidity and mortality is unclear. This review was originally published in 2006 and was updated in 2012 and again in 2016. OBJECTIVES: To assess the benefits and harms of postoperative epidural analgesia in comparison with postoperative systemic opioid-based analgesia for adults undergoing elective abdominal aortic surgery. SEARCH METHODS: In the updated review, we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and five trial registers in November 2014, together with reference checking to identify additional studies. SELECTION CRITERIA: We included all randomized controlled trials comparing postoperative epidural analgesia and postoperative systemic opioid-based analgesia for adults who underwent elective open abdominal aortic surgery. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information and data when required. We assessed the level of evidence according to the scale provided by the GRADE working group. MAIN RESULTS: We included 15 trials published from 1987 to 2009 with 1498 participants in this updated review. Participants had a mean age between 60.5 and 71.3 years. The percentage of women in the included studies varied from 0% to 28.1%. Adding an epidural to general anaesthesia for people undergoing abdominal aortic repair reduced myocardial infarction (risk ratio (RR) 0.54 (95% confidence interval (CI) 0.30 to 0.97); I(2) statistic = 0%; number needed to treat for one additional beneficial outcome (NNTB) 28 (95% CI 19 to 1423), visual or verbal analogical scale (VAS) scores up to three days after the surgery (mean difference (MD) -1.78 (95% CI -2.32 to -1.25); I(2) statistic = 0% for VAS scores on movement at postoperative day one), time to tracheal extubation (standardized mean difference (SMD) -0.42 (95% CI -0.70 to -0.15); I(2) statistic = 83%; equivalent to a mean reduction of 36 hours), postoperative respiratory failure (RR 0.69 (95% CI 0.56 to 0.85); I(2) statistic = 0%; NNTB 8 (95% CI 6 to 16)), gastrointestinal bleeding (OR 0.20 (95% CI 0.06 to 0.65); I(2) statistic = 0%; NNTB 32 (95% CI 27 to 74)) and time spent in the intensive care unit (SMD -0.23 (95% CI -0.41 to -0.06); I(2) statistic = 0%; equivalent to a mean reduction of six hours). We did not demonstrate a reduction in the mortality rate up to 30 days (RR 1.06 (95% CI 0.60 to 1.86); I(2) statistic = 0%). The level of evidence was low for mortality and time before tracheal extubation; moderate for myocardial infarction, respiratory failure and intensive care unit length of stay; and high for gastrointestinal bleeding and VAS scores. AUTHORS' CONCLUSIONS: Epidural analgesia provided better pain management, reduced myocardial infarction, time to tracheal extubation, postoperative respiratory failure, gastrointestinal bleeding, and intensive care unit length of stay compared with systemic opioid-based drugs. For mortality, we did not find a difference at 30 days.

Epidural local anaesthetics versus opioid-based analgesic regimens for postoperative gastrointestinal paralysis, vomiting and pain after abdominal surgery.

BACKGROUND: Gastrointestinal paralysis, nausea and vomiting and pain are major clinical problems following abdominal surgery. Anaesthetic and analgesic techniques that reduce pain and postoperative nausea and vomiting (PONV), while preventing or reducing postoperative ileus, may reduce postoperative morbidity, duration of hospitalization and hospital costs. This review was first published in 2001 and was updated by new review authors in 2016. OBJECTIVES: To compare effects of postoperative epidural analgesia with local anaesthetics versus postoperative systemic or epidural opioids in terms of return of gastrointestinal transit, postoperative pain control, postoperative vomiting, incidence of anastomotic leak, length of hospital stay and costs after abdominal surgery. SEARCH METHODS: We identified trials by conducting computerized searches of the Cochrane Central Register of Controlled Trials (CENTRAL) (2014, Issue 12), MEDLINE (from 1950 to December 2014) and EMBASE (from 1974 to December 2014) and by checking the reference lists of trials retained. When we reran the search in February 2016, we added 16 potential new studies of interest to the list of 'Studies awaiting classification' and will incorporate these studies into formal review findings during the next review update. SELECTION CRITERIA: We included parallel randomized controlled trials comparing effects of postoperative epidural local anaesthetic versus regimens based on systemic or epidural opioids. DATA COLLECTION AND ANALYSIS: We rated the quality of studies by using the Cochrane 'Risk of bias' tool. Two review authors independently extracted data and judged the quality of evidence according to the GRADE (Grades of Recommendation, Assessment, Development and Evaluation Working Group) scale. MAIN RESULTS: We included 128 trials with 8754 participants in the review, and 94 trials with 5846 participants in the analysis. Trials included in the review were funded as follows: charity (n = 19), departmental resources (n = 8), governmental sources (n = 15) and industry (in part or in total) (n = 15). The source of funding was not specified for the other studies.Results of 22 trials including 1138 participants show that an epidural containing a local anaesthetic will decrease the time required for return of gastrointestinal transit as measured by time to first flatus after an abdominal surgery (standardized mean difference (SMD) -1.28, 95% confidence interval (CI) -1.71 to -0.86; high quality of evidence; equivalent to 17.5 hours). The effect is proportionate to the concentration of local anaesthetic used. A total of 28 trials including 1559 participants reported a decrease in time to first faeces (stool) (SMD -0.67, 95% CI -0.86 to -0.47; low quality of evidence; equivalent to 22 hours). Thirty-five trials including 2731 participants found that pain on movement at 24 hours after surgery was also reduced (SMD -0.89, 95% CI -1.08 to -0.70; moderate quality of evidence; equivalent to 2.5 on scale from 0 to 10). From findings of 22 trials including 1154 participants we did not find a difference in the incidence of vomiting within 24 hours (risk ratio (RR) 0.84, 95% CI 0.57 to 1.23; low quality of evidence). From investigators in 17 trials including 848 participants we did not find a difference in the incidence of gastrointestinal anastomotic leak (RR 0.74, 95% CI 0.41 to 1.32; low quality of evidence). Researchers in 30 trials including 2598 participants noted that epidural analgesia reduced length of hospital stay for an open surgery (SMD -0.20, 95% CI -0.35 to -0.04; very low quality of evidence; equivalent to one day). Data on costs were very limited. AUTHORS' CONCLUSIONS: An epidural containing a local anaesthetic, with or without the addition of an opioid, accelerates the return of gastrointestinal transit (high quality of evidence). An epidural containing a local anaesthetic with an opioid decreases pain after abdominal surgery (moderate quality of evidence). We did not find a difference in the incidence of vomiting or anastomotic leak (low quality of evidence). For open surgery, an epidural containing a local anaesthetic would reduce the length of hospital stay (very low quality of evidence).

The use of ultrasound guidance for perioperative neuraxial and peripheral nerve blocks in children.

BACKGROUND: The use of ultrasound guidance for regional anaesthesia has become popular over the past two decades. However, it is not recognized by all experts as an essential tool. The cost of an ultrasound machine is substantially higher than the cost of other tools such as a nerve stimulator. OBJECTIVES: To determine whether ultrasound guidance offers any clinical advantage when neuraxial and peripheral nerve blocks are performed in children in terms of increasing the success rate or decreasing the rate of complications. SEARCH METHODS: We searched the following databases to March 2015: Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (OvidSP), EMBASE (OvidSP) and Scopus (from inception to 27 January 2015). SELECTION CRITERIA: We included all parallel randomized controlled trials (RCTs) that evaluated the effects of ultrasound guidance used when a regional blockade technique was performed in children, and that included any of our selected outcomes. DATA COLLECTION AND ANALYSIS: We assessed selected studies for risk of bias by using the assessment tool of The Cochrane Collaboration. Two review authors independently extracted data. We graded the level of evidence for each outcome according to the GRADE (Grades of Recommendation, Assessment, Development and Evaluation) Working Group scale. MAIN RESULTS: We included 20 studies (1241 participants) for which the source of funding was a government organization (two studies), a charitable organization (one study), an institutional department (four studies) or an unspecified source (11 studies); two studies declared that they received help from the industry (equipment loan). In 14 studies (939 participants), ultrasound guidance increased the success rate by decreasing the occurrence of a failed block: risk difference (RD) -0.11 (95% confidence interval (CI) -0.17 to -0.05); I(2) = 64%; number needed for additional beneficial outcome for a peripheral nerve block (NNTB) 6 (95% CI 5 to 8). Blocks were performed under general anaesthesia (usual clinical practice in this population); therefore, haemodynamic changes to the surgical stimulus (rather than classic sensory/motor blockade evaluation) were used to define success. For peripheral nerve blocks, the younger the child, the greater was the benefit. In eight studies (414 participants), pain scores at one hour in the post-anaesthesia care unit were reduced when ultrasound guidance was used; however, the clinical relevance of the difference was unclear (equivalent to -0.2 on a scale from 0 to 10). In eight studies (358 participants), block duration was longer when ultrasound guidance was used: standardized mean difference (SMD) 1.21 (95% CI 0.76 to 1.65; I(2) = 73%; equivalent to 62 minutes). Here again, younger children benefited most from ultrasound guidance. Time to perform the procedure was reduced when ultrasound guidance was used for pre-scanning before a neuraxial block (SMD -1.97, 95% CI -2.41 to -1.54; I(2) = 0%; equivalent to 2.4 minutes; two studies with 122 participants) or as an out-of-plane technique (SMD -0.68, 95% CI -0.96 to -0.40; I(2) = 0%; equivalent to 94 seconds; two studies with 204 participants). In two studies (122 participants), ultrasound guidance reduced the number of needle passes required to perform the block (SMD -0.90, 95% CI -1.27 to -0.52; I(2) = 0%; equivalent to 0.6 needle pass per participant). For two studies (204 participants), we could not demonstrate a difference in the incidence of bloody puncture when ultrasound guidance was used for neuraxial blockade, but we found that the number of participants was well below the optimal information size (RD -0.07, 95% CI -0.19 to 0.04). No major complications were reported for any of the 1241 participants. We rated the quality of evidence as high for success, pain scores at one hour, block duration, time to perform the block and number of needle passes. We rated the quality of evidence as low for bloody punctures. AUTHORS' CONCLUSIONS: Ultrasound guidance seems advantageous, particularly in young children, for whom it improves the success rate and increases the block duration. Additional data are required before conclusions can be drawn on the effect of ultrasound guidance in reducing the rate of bloody puncture.

Anaesthesia for hip fracture surgery in adults.

BACKGROUND: The majority of people with hip fracture are treated surgically, requiring anaesthesia. OBJECTIVES: The main focus of this review is the comparison of regional versus general anaesthesia for hip (proximal femoral) fracture repair in adults. We did not consider supplementary regional blocks in this review as they have been studied in another review. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL; the Cochrane Library; 2014, Issue 3), MEDLINE (Ovid SP, 2003 to March 2014) and EMBASE (Ovid SP, 2003 to March 2014). SELECTION CRITERIA: We included randomized trials comparing different methods of anaesthesia for hip fracture surgery in adults. The primary focus of this review was the comparison of regional anaesthesia versus general anaesthesia. The use of nerve blocks preoperatively or in conjunction with general anaesthesia is evaluated in another review. The main outcomes were mortality, pneumonia, myocardial infarction, cerebrovascular accident, acute confusional state, deep vein thrombosis and return of patient to their own home. DATA COLLECTION AND ANALYSIS: Two reviewers independently assessed trial quality and extracted data. We analysed data with fixed-effect (I(2) < 25%) or random-effects models. We assessed the quality of the evidence according to the criteria developed by the GRADE working group. MAIN RESULTS: In total, we included 31 studies (with 3231 participants) in our review. Of those 31 studies, 28 (2976 participants) provided data for the meta-analyses. For the 28 studies, 24 were used for the comparison of neuraxial block versus general anaesthesia. Based on 11 studies that included 2152 participants, we did not find a difference between the two anaesthetic techniques for mortality at one month: risk ratio (RR) 0.78, 95% confidence interval (CI) 0.57 to 1.06; I(2) = 24% (fixed-effect model). Based on six studies that included 761 participants, we did not find a difference in the risk of pneumonia: RR 0.77, 95% CI 0.45 to 1.31; I(2) = 0%. Based on four studies that included 559 participants, we did not find a difference in the risk of myocardial infarction: RR 0.89, 95% CI 0.22 to 3.65; I(2) = 0%. Based on six studies that included 729 participants, we did not find a difference in the risk of cerebrovascular accident: RR 1.48, 95% CI 0.46 to 4.83; I(2) = 0%. Based on six studies that included 624 participants, we did not find a difference in the risk of acute confusional state: RR 0.85, 95% CI 0.51 to 1.40; I(2) = 49%. Based on laboratory tests, the risk of deep vein thrombosis was decreased when no specific precautions or just early mobilization was used: RR 0.57, 95% CI 0.41 to 0.78; I(2) = 0%; (number needed to treat for an additional beneficial outcome (NNTB) = 3, 95% CI 2 to 7, based on a basal risk of 76%) but not when low molecular weight heparin was administered: RR 0.98, 95% CI 0.52 to 1.84; I(2) for heterogeneity between the two subgroups = 58%. For neuraxial blocks compared to general anaesthesia, we rated the quality of evidence as very low for mortality (at 0 to 30 days), pneumonia, myocardial infarction, cerebrovascular accident, acute confusional state, decreased rate of deep venous thrombosis in the absence of potent thromboprophylaxis, and return of patient to their own home. The number of studies comparing other anaesthetic techniques was limited. AUTHORS' CONCLUSIONS: We did not find a difference between the two techniques, except for deep venous thrombosis in the absence of potent thromboprophylaxis. The studies included a wide variety of clinical practices. The number of participants included in the review is insufficient to eliminate a difference between the two techniques in the majority of outcomes studied. Therefore, large randomized trials reflecting actual clinical practice are required before drawing final conclusions.

Sub-Tenon's anaesthesia versus topical anaesthesia for cataract surgery.

BACKGROUND: Local anaesthesia for cataract surgery can be provided by sub-Tenon's or topical anaesthesia. Both techniques offer possible advantages. This review, which originally was published in 2007 and was updated in 2014, was undertaken to compare these two anaesthetic techniques. OBJECTIVES: Our objectives were to compare the effectiveness of topical anaesthesia (with or without intracameral local anaesthetic) versus sub-Tenon's anaesthesia in providing pain relief during cataract surgery. We reviewed pain during administration of anaesthesia, postoperative pain, surgical satisfaction with operating conditions and patient satisfaction with pain relief provided, and we looked at associated complications. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials, MEDLINE and EMBASE (last search in November 2014) and the reference lists of published articles. We looked for conferences abstracts and trials in progress and placed no constraints on language or publication status. SELECTION CRITERIA: We included all randomized studies that compared sub-Tenon's anaesthesia versus topical anaesthesia for cataract surgery. DATA COLLECTION AND ANALYSIS: We assessed trial quality and extracted data in the format allowing maximal data inclusion. MAIN RESULTS: We included eight studies in this updated review but could retain in the analysis only seven studies on 742 operated eyes of 617 participants. Two cross-over trials included 125 participants, and five parallel trials included 492 participants. These studies were published between 1997 and 2005. The mean age of participants varied from 71.5 years to 83.5 years. The female proportion of participants varied from 54% to 76%. Compared with sub-Tenon's anaesthesia, topical anaesthesia (with or without intracameral injection) for cataract surgery increases intraoperative pain but decreases postoperative pain at 24 hours. The amplitude of the effect (equivalent to 1.1 on a score from 0 to 10 for intraoperative pain, and to 0.2 on the same scale for postoperative pain at 24 hours), although statistically significant, was probably too small to be of clinical relevance. The quality of the evidence was rated as high for intraoperative pain and moderate for pain at 24 hours. We did find differences in pain during administration of local anaesthetic (low level of evidence), and indications that surgeon satisfaction (low level of evidence) and participant satisfaction (moderate level of evidence) were less with topical anaesthesia. There was not enough evidence to say that one technique would result in a higher or lower incidence of intraoperative complications compared with the other. AUTHORS' CONCLUSIONS: Both topical anaesthesia and sub-Tenon's anaesthesia are accepted and safe methods of providing anaesthesia for cataract surgery. An acceptable degree of intraoperative discomfort has to be expected with either of these techniques. Randomized controlled trials on the effects of various strategies to prevent intraoperative pain during cataract surgery could prove useful.

Intraoperative use of low volume ventilation to decrease postoperative mortality, mechanical ventilation, lengths of stay and lung injury in patients without acute lung injury.

BACKGROUND: During the last decade, there has been a trend towards decreasing tidal volumes for positive pressure ventilation during surgery. It is not known whether this new trend is beneficial or harmful for patients. OBJECTIVES: To assess the benefit of intraoperative use of low tidal volume ventilation (< 10 mL/kg of predicted body weight) to decrease postoperative complications. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2014, Issue 9), MEDLINE (OvidSP) (from 1946 to 5 September 2014) and EMBASE (OvidSP) (from 1974 to 5 September 2014). SELECTION CRITERIA: We included all parallel randomized controlled trials (RCTs) that evaluated the effect of low tidal volumes (defined as < 10 mL/kg) on any of our selected outcomes in adult participants undergoing any type of surgery. We did not retain studies with participants requiring one-lung ventilation. DATA COLLECTION AND ANALYSIS: Two authors independently assessed the quality of the retained studies with the Cochrane 'Risk of bias' tool. We analysed data with both fixed-effect (I(2) statistic < 25%) or random-effects (I(2) statistic > 25%) models based on the degree of heterogeneity. When there was an effect, we calculated a number needed to treat for an additional beneficial outcome (NNTB) using the odds ratio. When there was no effect, we calculated the optimal size information. MAIN RESULTS: We included 12 studies in the review. In total these studies detailed 1012 participants (499 participants in the low tidal volume group and 513 in the high volume group). All studies included were at risk of bias as defined by the Cochrane tool. Based on nine studies including 899 participants, we found no difference in 0- to 30-day mortality between low and high tidal volume groups (risk ratio (RR) 0.79, 95% confidence interval (CI) 0.40 to 1.54; I(2) statistic 0%; low quality evidence). Based on four studies including 601 participants undergoing abdominal or spinal surgery, we found a lower incidence of postoperative pneumonia in the lower tidal volume group (RR 0.44, 95% CI 0.20 to 0.99; I(2) statistic 19%; moderate quality evidence; NNTB 19, 95% CI 14 to 169). Based on two studies including 428 participants, low tidal volumes decreased the need for non-invasive postoperative ventilatory support (RR 0.31, 95% CI 0.15 to 0.64; moderate quality evidence; NNTB 11, 95% CI 9 to 19). Based on eight studies including 814 participants, low tidal volumes during surgery decreased the need for postoperative invasive ventilatory support (RR 0.33, 95% CI 0.14 to 0.80; I(2) statistic 0%; NNTB 36, 95% CI 27 to 202; moderate quality evidence). Based on three studies including 650 participants, we found no difference in the intensive care unit length of stay (standardized mean difference (SMD) -0.01, 95% CI -0.22 to 0.20; I(2) statistic = 42%; moderate quality evidence). Based on eight studies including 846 participants, we did not find a difference in hospital length of stay (SMD -0.16, 95% CI -0.40 to 0.07; I(2) statistic 52%; moderate quality evidence). A meta-regression showed that the effect size increased proportionally to the peak pressure measured at the end of surgery in the high volume group. We did not find a difference in the risk of pneumothorax (RR 2.01, 95% CI 0.51 to 7.95; I(2) statistic 0%; low quality evidence). AUTHORS' CONCLUSIONS: Low tidal volumes (defined as < 10 mL/kg) should be used preferentially during surgery. They decrease the need for postoperative ventilatory support (invasive and non-invasive). Further research is required to determine the maximum peak pressure of ventilation that should be allowed during surgery.

Ability of hemostatic assessment to detect bleeding disorders and to predict abnormal surgical blood loss in children: a systematic review and meta-analysis.

BACKGROUND: Systematic preoperative coagulation testing is still widely used in children scheduled for surgery, although current guidelines recommend that a bleeding history should be the first choice for hemostatic assessment. We performed a systematic review with meta-analysis to evaluate the pertinence of bleeding questionnaire and screening laboratory testing to detect bleeding disorders (BDs) in children and to predict abnormal surgical blood loss. METHODS: A search was conducted in PubMed, EMBASE, MEDLINE(R), Cochrane Central Register of Controlled Trials, Health technology Assessment, and all EBM Reviews (Cochrane DSR, ACP Journal Club, DARE, CCTR, CMR, HTA, and NHSEED and EBM Reviews) up to October 22, 2013. Prospective trials containing 20 children or more and any tests evaluating either the ability of the test to detect a congenital BD or the ability of the test to predict increased surgical blood loss were retained. The quality of the study was judged with the Cochrane Collaboration Tool and two investigators extracted data independently. Data were combined to calculate the pooled diagnostic odds ratio (DOR) and their 95% confidence intervals (CI 95%). I(2) statistics were used to assess statistics heterogeneity. RESULTS: Data could be extracted from 16 studies. Best results for detecting a congenital abnormality at potential risk for increased surgical blood loss were obtained with the PFA-100 (DOR = 113.0; 95% CI, 22.6-566.2; I(2) = 0%) in two studies, followed by the bleeding time in two other studies (DOR = 110.7; 95% CI, 24.4-502.3; I(2) = 0%). With a high amount of heterogeneity, questionnaires showed disappointing performances (DOR = 7.9; 95% CI: 3.5-17.5; I(2) = 72.6%). CONCLUSION: Current evidence does not identify a tool that adequately predicts BDs and/or abnormal surgical blood loss in children. Questionnaires currently available do not perform well. In the setting of a pediatric coagulation clinic, the PFA-100 has the highest chance of detecting a BD. This meta-analysis highlights the weakness of the literature regarding the prediction of perioperative bleeding due to congenital hemostatic disorders in children.

Neuraxial anesthesia for the prevention of postoperative mortality and major morbidity: an overview of cochrane systematic reviews.

BACKGROUND: This analysis summarized Cochrane reviews that assess the effects of neuraxial anesthesia on perioperative rates of death, chest infections, and myocardial infarction. METHODS: A search was performed in the Cochrane Database of Systematic Reviews on July 13, 2012. We have included all Cochrane systematic reviews that examined subjects of any age undergoing any type of surgical (open or endoscopic) procedure, compared neuraxial anesthesia to general anesthesia alone for the surgical anesthesia, or neuraxial anesthesia plus general anesthesia to general anesthesia alone for the surgical anesthesia, and included death, chest infections, myocardial infarction, and/or serious adverse events as outcomes. Studies included in these reviews were selected on the same criteria. RESULTS: Nine Cochrane reviews were selected for this overview. Their scores on the Overview Quality Assessment Questionnaire varied from 4 to 6 of a maximal possible score of 7. Compared with general anesthesia, neuraxial anesthesia reduced the 0- to-30-day mortality (risk ratio [RR] 0.71; 95% confidence interval [CI], 0.53-0.94; I = 0%) based on 20 studies that included 3006 participants. Neuraxial anesthesia also decreased the risk of pneumonia (RR 0.45; 95% CI, 0.26-0.79; I = 0%) based on 5 studies that included 400 participants. No difference was detected in the risk of myocardial infarction between the 2 techniques (RR 1.17; 95% CI, 0.57-2.37; I = 0%) based on 6 studies with 849 participants. Compared with general anesthesia alone, adding neuraxial anesthesia to general anesthesia did not affect the 0- to-30-day mortality (RR 1.07; 95% CI, 0.76-1.51; I = 0%) based on 18 studies with 3228 participants. No difference was detected in the risk of myocardial infarction between combined neuraxial anesthesia-general anesthesia and general anesthesia alone (RR 0.69; 95% CI, 0.44-1.09; I = 0%) based on 8 studies that included 1580 participants. Adding a neuraxial anesthesia to general anesthesia reduced the risk of pneumonia (RR 0.69; 95% CI, 0.49-0.98; I = 9%) after adjustment for publication bias and based on 9 studies that included 2433 participants. The quality of the evidence was judged as moderate for all 6 comparisons. The quality of the reporting score of complications related to neuraxial blocks was 9 (4 to 12 [median {range}]) for a possible maximum score of 14. CONCLUSIONS: Compared with general anesthesia, neuraxial anesthesia may reduce the 0-to-30-day mortality for patients undergoing a surgery with an intermediate-to-high cardiac risk (level of evidence moderate). Large randomized controlled trials on the difference in death and major outcomes between regional and general anesthesia are required.