Baseline Gastric Volume in Fasting Diabetic Patients Is Not Higher than That in Nondiabetic Patients: A Cross-sectional Noninferiority Study.

BACKGROUND: The physiology of diabetes mellitus can increase the risk of perioperative aspiration, but there is limited and contradictory evidence on the incidence of "full stomach" in fasting diabetic patients. The aim of this study is to assess the baseline gastric content (using gastric ultrasound) in diabetic and nondiabetic patients scheduled for elective surgery who have followed standard preoperative fasting instructions. METHODS: This was a prospective, noninferiority study of 180 patients (84 diabetic and 96 nondiabetic patients). Bedside ultrasound was used for qualitative and quantitative assessment of the gastric antrum in the supine and right lateral decubitus positions. Fasting gastric volume was estimated based on the cross-sectional area of the gastric antrum and a validated model. The hypothesis was that diabetic patients would not have a higher baseline fasting gastric volume compared to nondiabetic patients, with a noninferiority margin of 0.4 ml/kg. Secondary aims included the comparison of the incidence of full stomach (solid content or more than 1.5 mL/kg of clear fluid), estimation of the 95th percentile of the gastric volume distribution in both groups, and examination of the association between gastric volume, glycemic control, and diabetic comorbidities. RESULTS: The baseline gastric volume was not higher in diabetic patients (0.81 ± 0.61 ml/kg) compared to nondiabetic patients (0.87 ± 0.53 ml/kg) with a mean difference of -0.07 ml/kg (95% CI, -0.24 to 0.10 ml/kg). A total of 13 (15.5%) diabetic and 11 (11.5%) nondiabetic patients presented more than 1.5 ml/kg of gastric volume (95% CI for difference, -7.1 to 15.2%). There was little correlation between the gastric volume and either the time since diagnosis or HbA1C. CONCLUSIONS: The data suggest that the baseline gastric volume in diabetic patients who have followed standard fasting instructions is not higher than that in nondiabetic patients.

Subomohyoid Anterior Suprascapular Block versus Interscalene Block for Arthroscopic Shoulder Surgery: A Multicenter Randomized Trial.

BACKGROUND: Interscalene brachial plexus block, the pain relief standard for shoulder surgery, is an invasive technique associated with important complications. The subomohyoid anterior suprascapular block is a potential alternative, but evidence of its comparative analgesic effect is sparse. The authors tested the hypothesis that anterior suprascapular block is noninferior to interscalene block for improving pain control after shoulder surgery. As a secondary objective, the authors evaluated the success of superior trunk (C5-C6 dermatomes) block with suprascapular block. METHODS: In this multicenter double-blind noninferiority randomized trial, 140 patients undergoing shoulder surgery were randomized to either interscalene or anterior suprascapular block with 15 ml of ropivacaine 0.5% and epinephrine. The primary outcome was area under the curve of postoperative visual analog scale pain scores during the first 24 h postoperatively. The 90% CI for the difference (interscalene-suprascapular) was compared against a -4.4-U noninferiority margin. Secondary outcomes included presence of superior trunk blockade, pain scores at individual time points, opioid consumption, time to first analgesic request, opioid-related side-effects, and quality of recovery. RESULTS: A total of 136 patients were included in the analysis. The mean difference (90% CI) in area under the curve of pain scores for the (interscalene-suprascapular) comparison was -0.3 U (-0.8 to 0.12), exceeding the noninferiority margin of -4.4 U and demonstrating noninferiority of suprascapular block. The risk ratio (95% CI) of combined superior trunk (C5-C6 dermatomes) blockade was 0.98 (0.92 to 1.01), excluding any meaningful difference in superior trunk block success rates between the two groups. When differences in other analgesic outcomes existed, they were not clinically important. CONCLUSIONS: The suprascapular block was noninferior to interscalene block with respect to improvement of postoperative pain control, and also for blockade of the superior trunk. These findings suggest that the suprascapular block consistently blocks the superior trunk and qualify it as an effective interscalene block alternative.

Intrathecal Morphine and Pulmonary Complications after Arthroplasty in Patients with Obstructive Sleep Apnea: A Retrospective Cohort Study.

BACKGROUND: Intrathecal morphine is commonly and effectively used for analgesia after joint arthroplasty, but has been associated with delayed respiratory depression. Patients with obstructive sleep apnea may be at higher risk of postoperative pulmonary complications. However, data is limited regarding the safety of intrathecal morphine in this population undergoing arthroplasty. METHODS: This retrospective cohort study aimed to determine the safety of intrathecal morphine in 1,326 patients with documented or suspected obstructive sleep apnea undergoing hip or knee arthroplasty. Chart review was performed to determine clinical characteristics, perioperative events, and postoperative outcomes. All patients received neuraxial anesthesia with low-dose (100 µg) intrathecal morphine (exposure) or without opioids (control). The primary outcome was any postoperative pulmonary complication including: (1) respiratory depression requiring naloxone; (2) pneumonia; (3) acute respiratory event requiring consultation with the critical care response team; (4) respiratory failure requiring intubation/mechanical ventilation; (5) unplanned admission to the intensive care unit for respiratory support; and (6) death from a respiratory cause. The authors hypothesized that intrathecal morphine would be associated with increased postoperative complications. RESULTS: In 1,326 patients, 1,042 (78.6%) received intrathecal morphine. The mean age of patients was 65 ± 9 yr and body mass index was 34.7 ± 7.0 kg/m. Of 1,326 patients, 622 (46.9%) had suspected obstructive sleep apnea (Snoring, Tired, Observed, Pressure, Body Mass Index, Age, Neck size, Gender [STOP-Bang] score greater than 3), while 704 of 1,326 (53.1%) had documented polysomnographic diagnosis. Postoperatively, 20 of 1,322 (1.5%) patients experienced pulmonary complications, including 14 of 1,039 (1.3%) in the exposed and 6 of 283 (2.1%) in the control group (P = 0.345). Overall, there were 6 of 1 322 (0.5%) cases of respiratory depression, 18 of 1,322 (1.4%) respiratory events requiring critical care team consultation, and 4 of 1,322 (0.3%) unplanned intensive care unit admissions; these rates were similar between both groups. After adjustment for confounding, intrathecal morphine was not significantly associated with postoperative pulmonary complication (adjusted odds ratio, 0.60 [95% CI, 0.24 to 1.67]; P = 0.308). CONCLUSIONS: Low-dose intrathecal morphine, in conjunction with multimodal analgesia, was not reliably associated with postoperative pulmonary complications in patients with obstructive sleep apnea undergoing joint arthroplasty.

Diagnostic Accuracy of Point-of-Care Gastric Ultrasound.

BACKGROUND: Pulmonary aspiration of gastric contents is associated with significant perioperative morbidity and mortality. Previous studies have investigated the validity, reliability, and possible clinical impact of gastric ultrasound for the assessment of gastric content at the bedside. In the present study, we examined the accuracy (evaluated as sensitivity, specificity, and likelihood ratios) of point-of-care gastric ultrasound to detect a "full stomach" in a simulated scenario of clinical equipoise. METHODS: After a minimum fasting period of 8 hours, 40 healthy volunteers were randomized in a 1:1 ratio to either remain fasted or ingest a standardized quantity of clear fluid or solid. Each subject was randomized twice on 2 independent study sessions at least 24 hours apart. A gastric ultrasound examination was performed by a blinded sonographer following a standardized scanning protocol. Using a combination of qualitative and quantitative findings, the result was summarized in a dichotomous manner as positive (any solid or >1.5 mL/kg of clear fluid) or negative (no solid and ≤1.5 mL/kg of clear fluid) for full stomach. RESULTS: Data from 80 study sessions were analyzed. In this simulated clinical scenario with a pretest probability of 50%, point-of-care gastric ultrasound had a sensitivity of 1.0 (95% confidence interval [CI], 0.925-1.0), a specificity of 0.975 (95% CI, 0.95-1.0), a positive likelihood ratio of 40.0 (95% CI, 10.33-∞), a negative likelihood ratio of 0 (95% CI, 0-0.072), a positive predictive value of 0.976 (95% CI, 0.878-1.0), and a negative predictive value of 1.0 (95% CI, 0.92-1.0). CONCLUSIONS: Our results suggest that bedside gastric ultrasound is highly sensitive and specific to detect or rule out a full stomach in clinical scenarios in which the presence of gastric content is uncertain.

Outcome Selection and Methodological Quality of Major and Minor Shoulder Surgery Studies: A Scoping Review.

BACKGROUND: Core outcome sets aim to select and standardize the choice of important outcomes reported in clinical trials to encourage more effective data synthesis, increase the reliability of comparing results, and minimize reporting bias. A core outcome set for elective shoulder surgery has yet to be defined, and therefore a systematic assessment of outcomes and methodology is necessary to inform the development of a core outcome set. QUESTIONS/PURPOSES: The purpose of this study was to examine randomized controlled trials (RCTs) of patients having elective major or minor shoulder surgery to (1) identify the outcome domains reported; (2) determine specific outcome measurement tools that were utilized; and (3) assess the work for methodological quality and risk of bias. METHODS: We conducted a scoping review (a review that identifies the nature and extent of research evidence) to explore the reported outcome domains, outcome tools, and methodological quality from RCTs conducted in shoulder surgery. We considered both major shoulder surgery (defined as arthroplasty, rotator cuff repair, stabilization procedures, biceps tenodesis, or Bankart repairs) and minor shoulder surgery (simple arthroscopy, capsular plication, lateral clavicular excisions, or subacromial decompression). We queried 10 electronic databases for studies published between January 2006 and January 2015. Studies were included if they were prospective, randomized controlled, clinical trials enrolling patients who received an elective shoulder surgical intervention. We extracted data relating to trial characteristics, primary outcomes, tools used to measure these outcomes as well as methodological quality indicators. We assessed indicators of methodological quality by exploring (1) the reproducibility of power analyses; and (2) whether the primary outcomes were powered to minimum clinically important differences. Risk of bias was also assessed with the Jadad score with scores between 0 (very high risk of bias) and 5 (very low risk). Findings were qualitatively analyzed and reported according to systematic and scoping review guidelines. We included 315 studies involving 30,232 patients; 266 studies investigated anesthetic, analgesic, or surgical interventions. RESULTS: Of the 315 studies included, the most common outcome domains evaluated were analgesic (n = 104), functional (n = 87), anesthetic (n = 56), and radiologic (n = 29) outcomes, with temporal patterns noted. Studies of major shoulder surgery most commonly reported functional primary outcome domains, whereas minor shoulder surgery studies most frequently reported analgesic primary outcome domains. There were 85 different primary outcome tools utilized, which included 20 functional, 20 anesthetic, 13 analgesic, and 12 radiologic. A methodological quality assessment revealed that 24% of studies had reproducible power analyses, 13% were powered to minimum clinically important differences, and risk of bias assessment demonstrated a median (interquartile range [range]) Jadad score of 4 (3-5 [1-5]). CONCLUSIONS: A wide range of outcome domains and outcome assessment tools are in common use in contemporary trials of patients undergoing elective surgery. Although some diversity is important to allow the assessment of patient populations that may have different goals, the large number of tools in common use may impair the ability of future meta-analyses to pool results effectively or even for systematic reviews to synthesize what is known. The limitations of methodological quality in RCTs may be improved by researchers following standard guidelines and considering the minimum clinically important differences in their trials to be of greater use to clinicians and their patients. LEVEL OF EVIDENCE: Level I, therapeutic study.

Phrenic Nerve Palsy and Regional Anesthesia for Shoulder Surgery: Anatomical, Physiologic, and Clinical Considerations.

Regional anesthesia has an established role in providing perioperative analgesia for shoulder surgery. However, phrenic nerve palsy is a significant complication that potentially limits the use of regional anesthesia, particularly in high-risk patients. The authors describe the anatomical, physiologic, and clinical principles relevant to phrenic nerve palsy in this context. They also present a comprehensive review of the strategies for reducing phrenic nerve palsy and its clinical impact while ensuring adequate analgesia for shoulder surgery. The most important of these include limiting local anesthetic dose and injection volume and performing the injection further away from the C5-C6 nerve roots. Targeting peripheral nerves supplying the shoulder, such as the suprascapular and axillary nerves, may be an effective alternative to brachial plexus blockade in selected patients. The optimal regional anesthetic approach in shoulder surgery should be tailored to individual patients based on comorbidities, type of surgery, and the principles described in this article.

Anesthesia Technique and Mortality after Total Hip or Knee Arthroplasty: A Retrospective, Propensity Score-matched Cohort Study.

BACKGROUND: This propensity score-matched cohort study evaluates the effect of anesthetic technique on a 30-day mortality after total hip or knee arthroplasty. METHODS: All patients who had hip or knee arthroplasty between January 1, 2003, and December 31, 2014, were evaluated. The principal exposure was spinal versus general anesthesia. The primary outcome was 30-day mortality. Secondary outcomes were (1) perioperative myocardial infarction; (2) a composite of major adverse cardiac events that includes cardiac arrest, myocardial infarction, or newly diagnosed arrhythmia; (3) pulmonary embolism; (4) major blood loss; (5) hospital length of stay; and (6) operating room procedure time. A propensity score-matched-pair analysis was performed using a nonparsimonious logistic regression model of regional anesthetic use. RESULTS: We identified 10,868 patients, of whom 8,553 had spinal anesthesia and 2,315 had general anesthesia. Ninety-two percent (n = 2,135) of the patients who had general anesthesia were matched to similar patients who did not have general anesthesia. In the matched cohort, the 30-day mortality rate was 0.19% (n = 4) in the spinal anesthesia group and 0.8% (n = 17) in the general anesthesia group (risk ratio, 0.42; 95% CI, 0.21 to 0.83; P = 0.0045). Spinal anesthesia was also associated with a shorter hospital length of stay (5.7 vs. 6.6 days; P < 0.001). CONCLUSIONS: The results of this observational, propensity score-matched cohort study suggest a strong association between spinal anesthesia and lower 30-day mortality, as well as a shorter hospital length of stay, after elective joint replacement surgery.

IV and Perineural Dexmedetomidine Similarly Prolong the Duration of Analgesia after Interscalene Brachial Plexus Block: A Randomized, Three-arm, Triple-masked, Placebo-controlled Trial.

BACKGROUND: Perineural and IV dexmedetomidine have each been suggested to prolong the duration of analgesia when administered in conjunction with peripheral nerve blocks. In the first randomized, triple-masked, placebo-controlled trial to date, the authors aimed to define and compare the efficacy of perineural and IV dexmedetomidine in prolonging the analgesic duration of single-injection interscalene brachial plexus block (ISB) for outpatient shoulder surgery. METHODS: Ninety-nine patients were randomized to receive ISB using 15 ml ropivacaine, 0.5%, with 0.5 µg/kg dexmedetomidine administered perineurally (DexP group), intravenously (DexIV group), or none (control group). The authors sequentially tested the joint hypothesis that dexmedetomidine prolongs the duration of analgesia and reduces the 24-h cumulative postoperative morphine consumption. Motor blockade, pain severity, hemodynamic variations, opioid-related side effects, postoperative neurologic symptoms, and patient satisfaction were also evaluated. RESULTS: Ninety-nine patients were analyzed. The duration of analgesia was 10.9 h (10.0 to 11.8 h) and 9.8 h (9.0 to 10.6 h) for the DexP and DexIV groups, respectively, compared with 6.7 h (5.6 to 7.8) for the control group (P < 0.001). Dexmedetomidine also reduced the 24-h cumulative morphine consumption to 63.9 mg (58.8 to 69.0 mg) and 66.2 mg (60.6 to 71.8 mg) for the DexP and DexIV groups, respectively, compared with 81.9 mg (75.0 to 88.9 mg) for the control group (P < 0.001). DexIV was noninferior to DexP for these outcomes. Both dexmedetomidine routes reduced the pain and opioid consumption up to 8 h postoperatively and did not prolong the duration of motor blockade. CONCLUSION: Both perineural and IV dexmedetomidine can effectively prolong the ISB analgesic duration and reduce the opioid consumption without prolonging motor blockade.

An Expedited Care Pathway with Ambulatory Brachial Plexus Analgesia Is a Cost-effective Alternative to Standard Inpatient Care after Complex Arthroscopic Elbow Surgery: A Randomized, Single-blinded Study.

BACKGROUND: Common standard practice after complex arthroscopic elbow surgery includes hospital admission for 72 h. The authors hypothesized that an expedited care pathway, with 24 h of hospital admission and ambulatory brachial plexus analgesia and continuous passive motion at home, results in equivalent elbow range of motion (ROM) 2 weeks after surgery compared with standard 72-h hospital admission. METHODS: A randomized, single-blinded study was conducted after obtaining approval from the research ethics board. Forty patients were randomized in a 1:1 ratio using a computer-generated list of random numbers into an expedited care pathway group (24-h admission) and a control group (72-h admission). They were treated equally aside from the predetermined hospital length of stay. RESULTS: Patients in the control (n = 19) and expedited care pathway (n = 19) groups achieved similar elbow ROM 2 weeks (119 ± 18 degrees and 121 ± 15 degrees, P = 0.627) and 3 months (130 ± 18 vs. 130 ± 11 degrees, P = 0.897) postoperatively. The mean difference in elbow ROM at 2 weeks was 2.6 degrees (95% CI, -8.3 to 13.5). There were no differences in analgesic outcomes, physical function scores, and patient satisfaction up to 3 months postoperatively. Total hospital cost of care was 15% lower in the expedited care pathway group. CONCLUSION: The results suggest that an expedited care pathway with early hospital discharge followed by ambulatory brachial plexus analgesia and continuous passive motion at home is a cost-effective alternative to 72 h of hospital admission after complex arthroscopic elbow surgery.

Point-of-care ultrasound defines gastric content and changes the anesthetic management of elective surgical patients who have not followed fasting instructions: a prospective case series.

PURPOSE: Pulmonary aspiration of gastric contents is a major cause of anesthesia morbidity and mortality. Point-of-care gastric ultrasound provides information regarding the type and volume of gastric content. The hypothesis of this prospective cohort study was that the addition of point-of-care gastric ultrasound to standard patient assessment results in changes in anesthetic management in at least 30% of elective surgical patients who do not follow fasting instructions. METHODS: Following Research Ethics Board approval and informed consent, elective surgical patients who did not follow fasting instructions were included in this prospective study. Documentation included the type of food ingested, the timing of the ingestion relative to the planned surgical time, and the treating anesthesiologist's management plan based on history alone. Next, an independent anesthesiologist not involved in the medical decision-making performed a focused gastric ultrasound examination. The results of the ultrasound exam were documented in a standardized fashion and made available to the attending anesthesiologist who then confirmed or revised the initial management plan. The treating anesthesiologist's actual (post-test) patient management was documented in a standardized fashion and compared with the initial (pre-test) management plan. RESULTS: Thirty-eight patients were included in this case series. Following point-of-care gastric ultrasound, there was a change in either the timing of anesthesia or the anesthetic technique (or both) in 27 patients (71%), with a net change towards a lower incidence of surgical delays. CONCLUSIONS: This prospective case series suggests that a standardized point-of care gastric ultrasound examination informs anesthesiologists' perceived level of aspiration risk and leads to changes in anesthetic management in a significant proportion of elective patients who did not follow fasting instructions.

The analgesic effects of proximal, distal, or no sciatic nerve block on posterior knee pain after total knee arthroplasty: a double-blind placebo-controlled randomized trial.

BACKGROUND: The analgesic efficacy of sciatic nerve block (SNB) after total knee arthroplasty (TKA) is unclear. Proximal and distal SNB are each reported to provide posterior knee analgesia, whereas others suggest that posterior knee pain is not important after TKA. This prospective, randomized, double-blind, parallel-arm, placebo-controlled trial examined whether proximal or distal SNB provides superior analgesia in the posterior knee compared with no SNB after TKA. METHODS: Sixty patients undergoing TKA were randomized to single-shot SNB using either the infragluteal (Proximal group) or popliteal (Distal group) technique, or no SNB (Placebo group). All patients received spinal anesthesia and continuous-femoral nerve blockade. A blinded observer assessed posterior and anterior knee pain at 2, 4, 6, 8, 12, and 24 h postoperatively. The primary outcome was moderate-to-severe posterior knee pain at 4 h postoperatively; secondary outcomes included SNB procedural time, needle passes, and discomfort. RESULTS: Fifty-three patients were analyzed. The proportion of patients (Proximal:Distal:Placebo) who experienced moderate-to-severe posterior knee pain was 18%:22%:89% (P<0.00001) at 2 h, 24%:28%:72% (P<0.01) at 4 h, and 12%:17%:78% (P=0.00003) at 6 h postoperatively. For the anterior knee, the proportion of patients reporting moderate-to-severe pain was 6%:11%:44% (P=0.02) at 2 h, 6%:6%:39% (P=0.012) at 4 h, and 12%:6%:44% (P=0.017) at 6 h postoperatively. Moderate-to-severe pain did not differ between groups beyond 6 h. Both proximal and distal SNB reduced rest pain in the posterior and anterior knee up to 8 h postoperatively compared with no SNB. The popliteal technique required shorter procedural time, fewer needle passes, and produced less discomfort. CONCLUSION: Proximal and distal SNB each reduce posterior and anterior knee pain after TKA compared with no SNB.

The addition of epidural local anesthetic to systemic multimodal analgesia following lumbar spinal fusion: a randomized controlled trial.

PURPOSE: This randomized trial aimed to evaluate the effects of adding continuous epidural analgesia with a bupivacaine and hydromorphone solution to systemic multimodal analgesia following one- or two-level lumbar spinal fusion. METHODS: Thirty-nine patients undergoing lumbar spinal fusion, stratified for sex and one- or two-level fusion, were randomized to receive a continuous postoperative epidural infusion of either 0.1% bupivacaine with 15 µg·mL(-1) hydromorphone (LA group) or 0.9% saline (NS group) at 6 mL·hr(-1) for 48 hr through an epidural catheter placed intraoperatively. All patients received a standardized postoperative multimodal analgesia regimen. Patients, healthcare providers, and research staff were blinded. The primary outcome measure was cumulative opioid consumption (oral morphine equivalent) during the first 48 hr postoperatively. RESULTS: The mean (SD) cumulative opioid consumption 48 hours postoperatively was 249.3 (143.3) mg in the NS group and 184.7 (208.1) mg in the LA group (mean difference 64.6 mg; 95% confidence interval -54.3 to 183.5; P = 0.27). There were no adverse events in either group. CONCLUSION: Continuous epidural infusion combined with systemic multimodal analgesia resulted in a mean reduction in 48-hr cumulative opioid consumption of 64.6 mg (95% confidence interval -54.3 to 183.5) following one- or two-level lumbar spinal fusion. This estimate of effect is imprecise, and the routine use of continuous epidural analgesia in this surgical population is not yet warranted. This trial was registered at www.clinicaltrials.gov : NCT00644111.

Bedside ultrasound assessment of gastric content: an observational study.

PURPOSE: There is a growing interest in the use of bedside ultrasonography to assess gastric content and volume. It has been suggested that the gastric antrum in particular can be assessed reliably by sonography. The aim of this observational study was to provide a qualitative description of the sonographic characteristics of the gastric antrum when the stomach is empty and following the ingestion of clear fluid, milk, and solid content. CLINICAL FEATURES: Six healthy volunteers were examined on four different occasions (24 scanning sessions): following a period of eight hours of fast and following ingestion of 200 mL of apple juice, 200 mL of 2% milk, and a standard solid meal (sandwich and apple juice). Examinations were performed following a standardized scanning protocol by two clinical anesthesiologists with previous experience in gastric sonography. For each type of gastric content, the sonographic characteristics of the antrum and its content are described and illustrated with figures. CONCLUSIONS: Bedside sonography can determine the nature of gastric content (nil, clear fluid, thick fluid/solid). This qualitative information by itself may be useful to assess risk of aspiration, particularly in situations when prandial status is unknown or uncertain.

Ready to scan? A systematic review of point of care ultrasound (PoCUS) for screening of obstructive sleep apnea (OSA) in the pediatric population.

STUDY OBJECTIVE: Diagnosis of obstructive sleep apnea (OSA) in pediatric practice is challenging, as screening questionnaires are inadequate and sleep studies are resource limited and time-consuming. A recent systematic review and meta-analysis of perioperative point-of-care ultrasound (PoCUS) in adults identified several parameters which correlate with OSA diagnosis and are the subject of an ongoing prospective study. The objective of this systematic review was to evaluate the usefulness of surface airway ultrasound as a PoCUS tool for OSA screening in the pediatric population. DESIGN: Databases were searched for observational cohort studies and randomized controlled trials of patients under 18 years of age undergoing quantitative surface US measurement of extra-thoracic airway structures where correlation or association was examined either directly to OSA diagnosis or indirectly to an alternative reference measure. Diagnostic properties and correlation between US parameters (index test) and reference measures were evaluated where possible. MAIN RESULTS: Of the initial 8499 screened articles, 12 articles (8 airway, 4 non-airway) evaluating 1237 patients were included. Six of these studies were conducted in the sleep/obesity clinic and six in in the perioperative population. Ten studies were prospective and two were cross sectional studies. Airway parameters which correlated with moderate-severe OSA were lateral pharyngeal wall thickness and total neck thickness at the retropharyngeal level. Tonsil volume was not correlated with OSA diagnosis or severity. In tonsillectomy patients, tonsil volume on preoperative ultrasound correlated well with volume of surgical specimens. Adenoid thickness correlated strongly with radiological and endoscopic measures of size and occlusion. CONCLUSION: Ultrasound measurement in children indicates several parameters which correlate with OSA diagnosis or with other reference measurements. This has not yet been validated as a diagnostic tool, however the recent emergence of research in this area is encouraging and the findings from this review will inform future studies.

Role of regional anesthesia and analgesia in enhanced recovery after colorectal surgery: a systematic review of randomized controlled trials.

BACKGROUND: Effective analgesia is an important element of enhanced recovery after surgery (ERAS), but the clinical impact of regional anesthesia and analgesia for colorectal surgery remains unclear. OBJECTIVE: We aimed to determine the impact of regional anesthesia following colorectal surgery in the setting of ERAS. EVIDENCE REVIEW: We performed a systematic review of nine databases up to June 2020, seeking randomized controlled trials comparing regional anesthesia versus control in an ERAS pathway for colorectal surgery. We analyzed the studies with successful ERAS implementation, defined as ERAS protocols with a hospital length of stay of ≤5 days. Data were qualitatively synthesized. Risk of bias was assessed using the Cochrane Risk of Bias 2 tool. FINDINGS: Of the 29 studies reporting ERAS pathways, only 13 comprising 1170 patients were included, with modest methodological quality and poor reporting of adherence to ERAS pathways. Epidural analgesia had limited evidence of outcome benefits in open surgery, while spinal analgesia with intrathecal opioids may potentially be associated with improved outcomes with no impact on length of stay in laparoscopic surgery, though dosing must be further investigated. There was limited evidence for fascial plane blocks or other regional anesthetic techniques. CONCLUSIONS: Although there was variable methodological quality and reporting of ERAS, we found little evidence demonstrating the clinical benefits of regional anesthetic techniques in the setting of successful ERAS implementation, and future studies must report adherence to ERAS in order for their interventions to be generalizable to modern clinical practice. PROSPERO REGISTRATION NUMBER: CRD42020161200.

Gastric sonography in the fasted surgical patient: a prospective descriptive study.

BACKGROUND: Aspiration pneumonia remains a serious anesthetic-related complication. A reliable diagnostic tool to assess gastric volume is currently lacking. We recently demonstrated that gastric sonography can provide reliable qualitative and quantitative information about gastric content and volume in healthy volunteers. In the current study, we performed a prospective qualitative and quantitative analysis of the gastric antrum in 200 fasted patients undergoing elective surgery. METHODS: A standardized gastric scanning protocol was applied before anesthetic induction. Patients were classified following a 3-point grading system based solely on qualitative sonographic assessment of the antrum in the supine and right lateral decubitus positions. RESULTS: Eighty-six patients were classified as grade 0 (empty antrum); 107 patients as grade 1 (minimal fluid volume detected only in the right lateral decubitus position); and 7 patients were classified as grade 2 (antrum clearly distended with fluid visible in both supine and lateral positions). The 3-point grading system correlated with total gastric fluid volume as predicted by a previously reported mathematical model. Essentially grade 0 corresponds to a completely empty stomach, grade 1 corresponds to negligible fluid volumes (16 ± 36 mL) within normal ranges expected for fasted patients, and grade 2 correlates with significantly higher predicted gastric fluid volumes (180 ± 83 mL) beyond previously reported "safe" limits. One patient with a grade 2 antrum had an episode of significant regurgitation of gastric contents on emergence from anesthesia. CONCLUSION: We propose a 3-point grading system based exclusively on qualitative sonographic assessment of the gastric antrum that correlates well with predicted gastric volume. This grading system could be a promising "biomarker" to assess perioperative aspiration risk. Before it can be applied widely to clinical practice, this diagnostic tool needs to be further validated and characterized.