Implementation Process and Evolution of a Laparotomy-Assisted 2-Port Fetoscopic Spina Bifida Closure Program.

INTRODUCTION: Prenatal closure of open spina bifida via open fetal surgery improves neurologic outcomes for infants in selected pregnancies. Fetoscopic techniques that are minimally invasive to the uterus aim to provide equivalent fetal benefits while minimizing maternal morbidities, but the optimal technique is undetermined. We describe the development, evolution, and feasibility of the laparotomy-assisted 2-port fetoscopic technique for prenatal closure of fetal spina bifida in a newly established program. METHODS: We conducted a retrospective cohort study of women consented for laparotomy-assisted fetoscopic closure of isolated fetal spina bifida. Inclusion and exclusion criteria followed the Management of Myelomeningocele Study (MOMS). Team preparation involved observation at the originating center, protocol development, ancillary staff training, and surgical rehearsal using patient-matched models through simulation prior to program implementation. The primary outcome was the ability to complete the repair fetoscopically. Secondary maternal and fetal outcomes to assess performance of the technique were collected prospectively. RESULTS: Of 57 women screened, 19 (33%) consented for laparotomy-assisted 2-port fetoscopy between February 2017 and December 2019. Fetoscopic closure was completed in 84% (16/19) cases. Over time, the technique was modified from a single- to a multilayer closure. In utero hindbrain herniation improved in 86% (12/14) of undelivered patients at 6 weeks postoperatively. Spontaneous rupture of membranes occurred in 31% (5/16) of fetoscopic cases. For completed cases, median gestational age at birth was 37 (range 27-39.6) weeks and 50% (8/16) of women delivered at term. Vaginal birth was achieved in 56% (9/16) of patients. One newborn had a cerebrospinal fluid leak that required postnatal surgical repair. CONCLUSION: Implementation of a laparotomy-assisted 2-port fetoscopic spina bifida closure program through rigorous preparation and multispecialty team training may accelerate the learning curve and demonstrates favorable obstetric and perinatal outcomes.

Remote Obstetric Anesthesia: Leveraging Telemedicine to Improve Fetal and Maternal Outcomes.

In the United States, the prevalence of pregnancy-related deaths has risen significantly over the past 20 years. Pregnant women at high risk for peripartum complications should undergo anesthesia consultation before delivery so that a management plan can be created between the obstetrician, anesthesiologist, and patient to ensure optimal outcomes for both the mother and newborn. However, few hospitals outside of major, urban, academic medical centers have dedicated anesthesiologists specially trained in obstetric anesthesia and the resources available to expedite optimization of high-risk parturient comorbidities. Telemedicine is a valuable tool by which evaluation, triaging, and multidisciplinary coordination can be provided for high-risk obstetric patients living in remote or rural communities without access to specialized, maternal care medical facilities. This review examines the existing literature regarding telemedicine use in preoperative anesthesia and antenatal obstetrics and identifies areas for future research. Furthermore, the benefits and potential barriers of implementing a telemedicine program specifically dedicated to obstetric anesthesia are discussed.

Analgesic efficacy of continuous intravenous magnesium infusion as an adjuvant to morphine for postoperative analgesia: a systematic review and meta-analysis.

BACKGROUND: The efficacy of perioperative intravenous magnesium administration on postoperative opioid use, opioid-related side effects (e.g., nausea and vomiting) and pain are uncertain, as randomized controlled trials on this topic have reported disparate results. The objective of this systematic review is to determine if perioperative magnesium reduces opioid use, opioid-related side effects, and postoperative pain. METHODS: An electronic search was conducted using the Library of Medicine's PubMed and EMBASE databases. Included studies consisted of randomized controlled trials in an adult population with a clearly defined comparison of perioperative intravenous magnesium administration to a control with a documented assessment of opioid usage and postoperative pain. Relevant data was abstracted from included studies. Pooled estimates for weighted mean difference (WMD) with 95% confidence intervals (CI) were obtained for our primary outcome (opioid usage) using the Cochrane Collaboration's RevMan version 4.2.7 (Cochrane Collaboration; Oxford, United Kingdom). WMD and odds ratios (OR) were calculated using a random effects model. RESULTS: The literature search ultimately yielded 22 trials, enrolling 1177 (599 magnesium, 578 control) patients, who were included in the analysis. A significant decrease in morphine usage by those patients who received magnesium was noted (WMD = -7.40; 95% CI: -9.40 to -5.41, p < 0.00001). Perioperative magnesium administration was not associated with a difference in postoperative nausea or vomiting (RR = 0.76; 95% CI: 0.52 to 1.09, p = 0.14). The pooled visual analog scores for pain at 4-6 hours after surgery were significantly less in those patients who received magnesium surgery (WMD = -0.67; 95% CI: -1.12 to -0.23, p = 0.003); however, there was no difference in pain scores at 20-24 hours after surgery (WMD = -0.25; 95% CI: -0.62 to 0.71, p = 0.17). CONCLUSION: Based on the results of this systematic review, perioperative intravenous magnesium may be a useful adjuvant for the management of postoperative pain providing analgesia through a different mechanism of action than that of opioids and would make a potential addition to a multimodal anlgesic treatment plan; however, the decrease in opioid use with perioperative magnesium infusion does not appear to be associated with a decresea in opioid-related side effects.

Single-Center Outcome of Fetoscopic Tracheal Balloon Occlusion for Severe Congenital Diaphragmatic Hernia.

OBJECTIVE: To assess feasibility and maternal and infant outcome after fetoscopic tracheal balloon occlusion in patients with severe congenital diaphragmatic hernia. METHODS: We conducted a prospective cohort study of fetuses with congenital diaphragmatic hernia and observed/expected lung/head ratio less than 30%. Eligible women had planned fetoscopic tracheal balloon occlusion at 26 0/7-29 6/7 weeks of gestation and balloon removal 4-6 weeks later. Standardized prenatal and postnatal care was at a single institution. Fetoscopic tracheal balloon occlusion details, lung growth, obstetric complications, birth outcome, and infant outcome details until discharge were evaluated. RESULTS: Of 57 women screened, 14 (25%) were enrolled between 2015 and 2019. The congenital diaphragmatic hernia was left in 12 (86%); the pre-fetoscopic tracheal balloon occlusion observed/expected lung/head ratio was 23.2% (range 15.8-29.0%). At a median gestational age of 28 5/7 weeks (range 27 3/7-29 6/7), fetoscopic tracheal balloon occlusion was successful in all cases, and balloons remained in situ. Removal was elective in 10 (71%) patients, by ultrasound-guided needle puncture in eight (57%), and occurred at a median of 33 4/7 weeks of gestation (range 32 1/7-34 4/7; median occlusion 34 days, range 17-44). The post-fetoscopic tracheal balloon occlusion observed/expected lung/head ratio increased to a median of 62.8% (44.0-108) and fell to a median of 46.6% (range 30-92) after balloon removal (all Mann Whitney U, P<.003). For prevention of preterm birth, all patients received vaginal progesterone; 11 (79%) required additional tocolytics, three (21%) had vaginal pessary placement for cervical shortening, and five (36%) had amnioreduction for polyhydramnios. Median gestational age at birth was 39 2/7 weeks (range 33 6/7-39 4/7), with term birth in eight (57%) patients. Twelve (86%) neonates required high-frequency ventilation, and seven (50%) required extracorporeal membrane oxygenation for a median of 7 days (range 3-19). All neonates needed patch repair. Neonatal survival was 93% (n=13, 95% CI 49-100%), and survival to hospital discharge was 86% (n=12, 95% CI 44-100%). CONCLUSION: Fetoscopic tracheal balloon occlusion for severe congenital diaphragmatic hernia was feasible in our single-center setting, with few obstetric complications and favorable infant outcome. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, NCT02710968.

Postoperative pain management in the elderly undergoing thoracic surgery.

The management of postoperative pain in the elderly represents a considerable challenge because these patients are generally at higher risk for postoperative complications. There are several analgesic options, some of which may influence perioperative morbidity in this high-risk group of patients. Although use of regional analgesia, particularly epidural analgesia is associated with some benefits, including a decrease in perioperative morbidity, there are side effects and complications (eg, medication-related side effects, epidural hematoma, infection) from these and other techniques, and the clinician should evaluate the benefits and risks of each technique on an individual basis. Nevertheless, the available data suggest that use of regional analgesic techniques (ie, epidural and paravertebral catheters) is associated with a decrease in perioperative pulmonary complications.

Regional techniques and outcome: what is the evidence?

PURPOSE OF REVIEW: Despite some controversy regarding the strength of the available data, the use of regional anesthesia and analgesia does provide improvement in patient outcomes. Although the majority of available data have examined the effect of epidural anesthesia and analgesia on patient outcomes, an increasing number of studies recently have investigated the effect of peripheral regional techniques on patient outcomes. RECENT FINDINGS: Data generally indicate that the perioperative use of regional anesthesia and analgesia may be associated with improvement in both major (e.g. mortality, major morbidity) outcomes and rehabilitation. The majority of evidence favors an ability of epidural analgesia to reduce postoperative cardiovascular and pulmonary complications and there is also consistent evidence that epidural analgesia with local anesthetics is associated with faster resolution of postoperative ileus after major abdominal surgery. Overall, regional analgesic techniques provide statistically superior analgesia compared with systemic opioids. SUMMARY: Perioperative use of regional analgesic techniques may provide improvement in conventional outcomes, although the benefit appears to be limited to high-risk patients and those undergoing high-risk procedures. The benefits conferred by perioperative regional anesthetic techniques need to be weighed against any potential risks and this should be assessed on an individual basis.

Opportunities and challenges for junior investigators conducting pain clinical trials.

INTRODUCTION: Clinical investigation serves a vital role to advance treatment and management stratgies for patients with pain. For those new to clinical investigation, key advice for both the novice clinical-investigator and the experienced researcher expanding to translational work may accelerate research efforts. OBJECTIVE: To review foundational material relevant to junior investigators focusing on pain clinical trials, with an emphasis on randomized controlled trials. METHODS: We reviewed recent publications and resources relevant to clinical investigators, with a particular emphasis on pain research. RESULTS: Understanding the approaches and barriers to clinical pain research is a first step to building a successful investigative portfolio. Key components of professional development include motivation, mentorship, and collaborative approaches to research. Many junior clinical-investigators face challenges in pursing research careers and sparking iterative progress towards success in clinical trials. Pain-specific research metrics and goals-including hypothesis development, study design considerations, and regulatory concerns-are also important considerations to junior investigators who pursue clinical trails. Approaches to build toward collaborative and independent funding are essential for investigators. CONCLUSIONS: This work provides a foundation for understanding the clinical research process and helps inform the goals and plans of clinical-investigators.

Atrial natriuretic peptide production and natriuretic peptide receptors in the human uterus and their effect on myometrial relaxation.

OBJECTIVE: The objective of the study was to identify the effect of atrial natriuretic peptide (ANP) on uterine contractility, production of ANP, and natriuretic peptide receptor (NPR) expression in human myometrial tissue. STUDY DESIGN: In an institutional review board-approved study, gravid human myometrium was obtained from patients undergoing cesarean section. Uterine contractility was examined using isometric force tension studies. After regular uterine contractions were obtained with oxytocin, ANP was added in increasing concentrations. ANP concentration was measured from myometrial tissue using radioimmunoassay (RIA). Primary myometrial cell culture was performed and treated with nifedipine vs oxytocin. RIA was performed on these cells and the cell culture media. Western blot analysis was performed on uterine tissue samples for natriuretic peptide receptors. RESULTS: With increasing concentration of ANP (starting at 3 pM), myometrial contraction frequency decreased. ANP was identified in primary cultured myometrial cells and cell culture media. Myometrial ANP concentration increased with advancing gestational age. The concentration of ANP decreased within myometrial cells treated with oxytocin. The amount of ANP in the cell culture media increased from cells treated with nifedipine. Western blot identified NPR-A, -B, and -C in myometrial tissue. NPR-A expression was significantly increased in preterm samples. CONCLUSION: ANP has a dose dependent effect on uterine relaxation. ANP is present in human myometrial cells and appears to be secreted by myometrial cells. The concentration of ANP may vary with gestational age and modulators of uterine contractility. NPR-A, -B, and -C receptor proteins are present in myometrial tissue. NPR-A levels may correlate with gestational age.

Acute Cardiac Effects of Severe Pre-Eclampsia.

BACKGROUND: Pre-eclampsia with severe features (PEC) is a pregnancy-specific syndrome characterized by severe hypertension and end-organ dysfunction, and is associated with short-term adverse cardiovascular events, including heart failure, pulmonary edema, and stroke. OBJECTIVES: The authors aimed to characterize the short-term echocardiographic, clinical, and laboratory changes in women with PEC, focusing on right ventricular (RV) systolic pressure (RVSP) and echocardiographic-derived diastolic, systolic, and speckle tracking parameters. METHODS: In this prospective observational study, the authors recruited 63 women with PEC and 36 pregnant control patients. RESULTS: The PEC cohort had higher RVSP (31.0 ± 7.9 mm Hg vs. 22.5 ± 6.1 mm Hg; p < 0.001) and decreased global RV longitudinal systolic strain (RVLSS) (-19.6 ± 3.2% vs. -23.8 ± 2.9% [p < 0.0001]) when compared with the control cohort. For left-sided cardiac parameters, there were differences (p < 0.001) in mitral septal e' velocity (9.6 ± 2.4 cm/s vs. 11.6 ± 1.9 cm/s), septal E/e' ratio (10.8 ± 2.8 vs. 7.4 ± 1.6), left atrial area size (20.1 ± 3.8 cm2 vs. 17.3 ± 2.9 cm2), and posterior and septal wall thickness (median [interquartile range]: 1.0 cm [0.9 to 1.1 cm] vs. 0.8 cm [0.7 to 0.9 cm], and 1.0 cm [0.8 to 1.2 cm] vs. 0.8 cm [0.7 to 0.9 cm]). Eight women (12.7%) with PEC had grade II diastolic dysfunction, and 6 women (9.5%) had peripartum pulmonary edema. CONCLUSIONS: Women with PEC have higher RVSP, higher rates of abnormal diastolic function, decreased global RVLSS, increased left-sided chamber remodeling, and higher rates of peripartum pulmonary edema, when compared with healthy pregnant women.

The Weekend Effect in Hospitalized Patients: A Meta-Analysis.

BACKGROUND: The presence of a "weekend effect" (increased mortality rate during Saturday and/or Sunday admissions) for hospitalized inpatients is uncertain. PURPOSE: We performed a systematic review to examine the presence of a weekend effect on hospital inpatient mortality. DATA SOURCES: PubMed, EMBASE, SCOPUS, and Cochrane databases (January 1966-April 2013) were utilized for our search. STUDY SELECTION: We examined the mortality rate for hospital inpatients admitted during the weekend compared with those admitted during the workweek. To be included, the study had to provide discrete mortality data around the weekends (including holidays) versus weekdays, include patients who were admitted as inpatients over the weekend, and be published in English. DATA EXTRACTION: The primary outcome was all-cause weekend versus weekday mortality with subgroup analysis by personnel staffing levels, rates and times to procedures rates and delays, or illness severity. DATA SYNTHESIS: A total of 97 studies (N = 51,114,109 patients) were examined. Patients admitted on the weekends had a significantly higher overall mortality (relative risk, 1.19; 95% confidence interval, 1.14-1.23). With regard to the subgroup analyses, patients admitted on the weekends consistently had higher mortality than those admitted during the week, regardless of the levels of weekend/weekday differences in staffing, procedure rates and delays, and illness severity. CONCLUSIONS: Hospital inpatients admitted during weekends may have a higher mortality rate compared with inpatients admitted during the weekdays.

The Analgesic Efficacy of Nonsteroidal Anti-inflammatory Agents (NSAIDs) in Patients Undergoing Cesarean Deliveries: A Meta-Analysis.

BACKGROUND AND OBJECTIVES: Postoperative pain after cesarean delivery, which accounts for approximately 1 in 3 live births in the United States, can be severe in many patients. Nonsteroidal anti-inflammatory agents (NSAIDs) are potent analgesics that are effective in the treatment of postoperative pain. In this meta-analysis, we assessed the analgesic efficacy of NSAIDs in postoperative cesarean delivery patients. METHODS: An electronic literature search of the Library of Medicine's PubMed, Cochrane CENTRAL, Scopus, and EMBASE databases was conducted in May 2013 and updated in January 2015 (Appendix, Supplemental Digital Content 1, http://links.lww.com/AAP/A174). Searches were limited to randomized controlled trials. The primary outcome variable was visual analog scale or numerical rating scale pain scores. Secondary outcomes included cumulative postoperative opioid consumption and opioid-related adverse effects (drowsiness/sedation, nausea, and vomiting). Data extraction was performed independently by 2 reviewers. Extracted data were input into Review Manager. RESULTS: Twenty-two randomized controlled trials compared a NSAID (n = 639) to a control (n = 674). Patients in the NSAID group versus control reported lower pain scores at 12 hours (P = 0.003) and at 24 hours (P < 0.001). Subgroup analysis showed a significant difference in pain scores at 24 hours, with patients receiving NSAIDs via intravenous/intramuscular (P < 0.001) route, but not the oral (P = 0.39) or rectal routes (P = 0.99). Significantly lower average pain scores were reported for pain with movement at 24 hours in the NSAID group (P = 0.001). Patients in the NSAID group versus controls consumed significantly less opioids (P < 0.001) and had significantly less drowsiness/sedation (P = 0.03), but there was no significant difference between the groups with regard to nausea or vomiting (P = 0.48 and P = 0.17, respectively). CONCLUSIONS: The perioperative use of NSAIDs in cesarean delivery patients will result in a significantly lower pain scores, less opioid consumption, and less drowsiness/sedation but no difference in nausea or vomiting compared to those who did not receive NSAIDs. Further research should address the optimal NSAID regimen and examine the effect of improved analgesia on patient-centered outcomes such as patient satisfaction and quality of breastfeeding.

The role of perioperative chewing gum on gastric fluid volume and gastric pH: a meta-analysis.

STUDY OBJECTIVE: To determine if preoperative gum chewing affects gastric pH and gastric fluid volume. DESIGN: Systematic review and meta-analysis. METHODS: Data sources included Cochrane, PubMed, and EMBASE databases from inception to June 2012 and reference lists of known relevant articles without language restriction. Randomized controlled trials in which a treatment group that chewed gum was compared to a control group that fasted were included. Relevant data, including main outcomes of gastric fluid volume and gastric pH, were extracted. RESULTS: Four studies involving 287 patients were included. The presence of chewing gum was associated with small but statically significant increases in gastric fluid volume (mean difference = 0.21 mL/kg; 95% confidence interval, 0.02-0.39; P = .03) but not in gastric pH (mean difference = 0.11 mL/kg; 95% confidence interval, -0.14 to 0.36; P = .38). Gastric fluid volume and gastric pH remained unchanged in subgroup analysis by either sugar or sugarless gum type. CONCLUSIONS: Chewing gum in the perioperative period causes small but statically significant increases in gastric fluid volume and no change in gastric pH. The increase in gastric fluid most likely is of no clinical significance in terms of aspiration risk for the patient. Elective surgery should not necessarily be canceled or delayed in healthy patients who accidentally chew gum preoperatively.

Evaluation of epidural and peripheral nerve catheter heating during magnetic resonance imaging.

BACKGROUND: Many epidural and peripheral nerve catheters contain conducting wire that could heat during magnetic resonance imaging (MRI), requiring removal for scanning. METHODS: We tested 2 each of 6 brands of regional analgesia catheters (from Arrow International [Reading, Pennsylvania], B. Braun Medical Inc [Bethlehem, Pennsylvania], and Smiths Medical/Portex [Keene, New Hampshire]) for exposure to clinical 1.5- and 3-T MRI. Catheters testing as nonmagnetic were placed in an epidural configuration in a standard human torso-sized phantom, and an MRI pulse sequence applied at the maximum scanner-allowed radiofrequency specific absorption rate (SAR) for 15 minutes. Temperature and SAR exposure were sampled during MRI using multiple fiberoptic temperature sensors. RESULTS: Two catheters (the Arrow StimuCath Peripheral Nerve and B. Braun Medical Perifix FX Epidural) were found to be magnetic and not tested further. At 3 T, exposure of the remaining 3 epidural and 1 peripheral nerve catheter to the scanner's maximum RF exposure elicited anomalous heating of 4°C to 7°C in 2 Arrow Epidural (MultiPort and Flex-Tip Plus) catheters at the entry points. Temperature increases for the other catheters at 3 T, and all catheters at 1.5 T were 1.4°C or less. When normalized to the body-average US Food and Drug Administration guideline SAR of 4 W/kg, maximum projected temperature increases were 0.1°C to 2.5°C at 1.5 T and 0.7°C to 2.7°C at 3 T, except for the Arrow MultiPort Flex-Tip Plus catheter at 3 T whose increase was 14°C. CONCLUSIONS: Most but not all catheters can be left in place during 1.5-T MRI scans. Heating of less than 3°C during MRI for most catheters is not expected to be injurious. While heating was lower at 1.5 T versus 3 T, performance differences between products underscore the need for safety testing before performing MRI.

Analgesic efficacy of intravenous naloxone for the treatment of postoperative pruritus: a meta-analysis.

OBJECTIVES: Pruritus may be a significant problem for patients in the postoperative period. There are many options for the treatment of pruritus including intravenous (IV) naloxone. However, it is not clear whether the use of IV naloxone may also affect analgesia or other opioid-related side effects. The authors have performed a systematic review to further examine this issue. METHODS: Systematic literature searches of the National Library of Medicine's PubMed and EMBASE databases were conducted using terms related to postoperative use of IV naloxone. Only randomized controlled trials comparing IV naloxone used either as a continuous infusion or part of an IV patient-controlled analgesia (PCA) regimen after surgical procedures were considered. The data on pertinent study characteristics and relevant outcomes were extracted from accepted articles. There was no restriction on language for inclusion. Meta-analysis was performed using the Review Manager 4.2.10 (The Cochrane Collaboration, 2004). A random effects model was used. RESULTS: The literature searches yielded eight articles that met all inclusion criteria. There were a total of 424 subjects in the naloxone group and 376 in the saline group. The authors found that the use of naloxone was associated with a decreased risk for pruritus (odds ratio [OR] = 0.40, 95% confidence interval [CI] = 0.21-0.79, p = 0.006] and nausea [OR = 0.62, 95% CI = 0.43-0.89, p = 0.009]. However, the use of IV naloxone (vs no naloxone) did not significantly influence the risk of postoperative emesis [OR = 0.97, 95% CI = 0.70-1.33, p = 0.83], opioid consumption [OR = 0.29, 95% CI = -3.54-4.13, p = 0.88], or sedation [OR = 0.82, 95% CI = 0.38-1.74, p = 0.60]. Finally, the use of IV naloxone did not appear to be associated with any significant change in visual analog score pain scores at 24 hours postoperatively (weighted mean difference = -0.14, 95% CI = -0.50-0.23, p = 0.46). CONCLUSIONS: Our pooled analysis examining the analgesic efficacy of IV naloxone (either as a continuous infusion or IV PCA) revealed that naloxone was associated with a decrease in pruritus and nausea without any increase in pain scores. When compared with controls, the use of IV naloxone was not associated with any significant changes in opioid consumption or with the risk of sedation or emesis.

Analgesic efficacy of ultrasound-guided regional anesthesia: a meta-analysis.

STUDY OBJECTIVE: To determine if the use of ultrasound guidance (vs non-ultrasound techniques) improves the success rate of nerve blocks. DESIGN: Meta-analysis of randomized controlled trials (RCTs) in the published literature. SETTING: University medical center. MEASUREMENTS: 16 RCTs of patients undergoing elective surgical procedures were studied. Patients underwent ultrasound-guided or non-ultrasound techniques (nerve stimulation, surface landmark) for peripheral nerve blocks. Success rates were measured. MAIN RESULTS: Ultrasound guidance (vs all non-ultrasound techniques) was associated with a significant increase in the success rate of nerve blocks [relative risk (RR) = 1.11 (95% confidence interval [CI]: 1.06 to 1.17, P < 0.0001]). When compared with nerve stimulator techniques only, ultrasound guidance was still associated with an increase in the success rate (RR = 1.11 [95% CI: 1.05 to 1.17, P = 0.0001]). For specific blocks, ultrasound guidance (vs all non-ultrasound) was associated with a significant increase in successful brachial plexus (all) nerve blocks (RR = 1.11 [95% CI: 1.05 to 1.20, P = 0.0001]), sciatic popliteal nerve block (RR = 1.22 [95% CI: 1.08 to 1.39, P = 0.002]) and brachial plexus axillary nerve block (RR = 1.13 [95% CI: 1.00 to 1.26, P = 0.05]) but not brachial plexus infraclavicular nerve block (RR = 1.25 [95% CI: 0.88 to 1.76, P = 0.22]). CONCLUSIONS: Ultrasound-guided peripheral nerve block is associated with an increased overall success rate when compared with nerve stimulation or other methods. Ultrasound-guided techniques also increase the success rate of some specific blocks.

The effect of intravenous opioid patient-controlled analgesia with and without background infusion on respiratory depression: a meta-analysis.

BACKGROUND: Although the addition of a background infusion for intravenous patient-controlled analgesia (IV-PCA) has been identified as a risk factor for the development of respiratory depression, this has not clearly been examined in a systematic fashion. The authors undertook a systematic review and meta-analysis of available randomized controlled trials (RCTs) to examine whether the addition of a background or continuous infusion to an IV-PCA regimen would be associated with an increased risk of respiratory depression. METHODS: Studies were identified by searching the National Library of Medicine's PubMed database (1966 to November 30, 2008). Inclusion criteria were a clearly defined analgesic technique of demand-only IV-PCA versus IV-PCA utilizing both a demand dose and background infusion, opioid medication used, and randomized trials. Data were abstracted and analyzed with the RevMan 4.2.7 (The Cochrane Collaboration, 2004). RESULTS: The search yielded 687 abstracts from which the original articles were obtained and data abstracted with a total of 14 articles analyzed. There were 402 subjects in the continuous IV-PCA with demand group versus the 394 subjects in the demand-only IV-PCA group. Addition of a background infusion to the demand dose for IV-PCA with opioids was associated with a significant increased risk for respiratory depression (odds ratio [OR] = 4.68, 95% confidence interval [CI]: 1.20-18.21). Subgroup analysis revealed that this increased risk was seen in adult but not in pediatric patients. CONCLUSIONS: Our meta-analysis indicates that the addition of a continuous or background infusion to the demand dose for IV-PCA is associated with a higher incidence of respiratory events than demand IV-PCA alone in adult but not in pediatric patients; however, our overall results should be interpreted with caution due to the relatively small sample size and the wide range of definitions for respiratory depression in studies examined.

Comparison of the postoperative analgesic efficacy of intravenous patient-controlled analgesia with tramadol to intravenous patient-controlled analgesia with opioids.

BACKGROUND: Intravenous patient-controlled analgesia (IV PCA) with tramadol is an accepted method to deliver postoperative analgesia outside North America; however, the analgesic efficacy of this analgesic agent when compared with IVPCA with opioids is uncertain. As such, the authors undertook a systematic review to compare the analgesic efficacy of IVPCA tramadol with that of IVPCA with opioids. METHODS: The authors used the National Library of Medicine's Medline database to search for terms related to tramadol and patient-controlled analgesia. Inclusion criteria were randomized controlled trials (RCTs) comparing IVPCA tramadol with IVPCA opioid and RCTs published in the English language. Relevant data were abstracted from accepted studies. Meta-analysis was performed using RevMan 4.2.10 (The Cochrane Collaboration, 2004). A random effects model was used. RESULTS: A total of 190 abstracts were obtained from the above search, and a total of 12 RCTs met the above inclusion criteria. There was no difference in weighted visual analog scale pain scores between IVPCA tramadol versus IVPCA opioid at 48 hours postoperatively or risk of sedation or fatigue. IVPCA tramadol was associated with a higher odds of postoperative nausea and vomiting [odds ratio (OR) = 1.52, 95% confidence interval (CI) = 1.07-2.14) but a lower odds of pruritus (OR = 0.43, 95% CI = 0.19-0.98). DISCUSSION: IVPCA tramadol appears to produce similar pain scores when compared with that from IVPCA opioids; however, the side effect profile is different between the two groups. Because of the relatively small sample size, no determination of the relative "safety" (eg, respiratory depression) of one regimen over the other can be made, and larger RCTs would be needed for such a determination.

Methodological quality of randomized controlled trials of postoperative epidural analgesia: validation of the Epidural Analgesia Trial Checklist as a specific instrument to evaluate methodology.

BACKGROUND: The overall benefits of epidural analgesia are controversial, in part because of the varying quality of methodology in published randomized controlled trials (RCTs). We performed a systematic review of available RCTs to examine the methodological quality of epidural analgesia trials. Current instruments for evaluating the quality of methodology are generic; thus, we also developed a specific assessment tool named Epidural Analgesia Trial Checklist (EATC). METHODS: The National Library of Medicine's PubMed database was searched (1966 to January 2006) for RCTs of epidural analgesia. All RCTs that had epidural infusion analgesia in at least 1 study arm and as primary intervention for randomization were included. Two independent reviewers were given blinded full-text paper versions of each article and reviewed all articles for inclusion in this study. Study characteristics were extracted from accepted RCTs, and reviewers completed the standardized 7-item Jadad score, 22-item Consolidated Standards of Reporting Trials (CONSORT) checklist, and 8-item EATC for evaluation of methodological quality. RESULTS: A total of 321 articles met all inclusion criteria. The overall median (first, third quartiles) Jadad, CONSORT, and EATC scores were 2 (1, 3), 10 (8, 11), and 4 (3, 6) (of maximum scores of 5, 22, and 8), respectively. For all assessments, we found significantly higher methodological study quality for articles with a larger study population size, those written by a first author affiliated with an anesthesiology department, and studies published after release of the CONSORT statement with a significant overall increase in methodological quality over time. There was no effect on methodological quality with regard to region of publication or number of centers. There was relatively high interrater agreement when using the EATC (κ = 0.92). The items most frequently lacking from the studies captured using the EATC were appropriate description/definition of adverse effects (11.8% of all studies properly reported this), proper presentation of visual analog scale (VAS) pain scores (31.2%), and assessment of VAS pain both at rest and with activity (39.9%). CONCLUSIONS: Methodology scores for epidural analgesia RCTs have improved over time. The EATC seems to correlate well with other commonly used generic assessments for methodological RCT quality and be useful for assessing methodological quality of epidural RCTs. Future epidural analgesia RCTs should focus on improving appropriate description/definition of adverse effects, proper presentation of VAS pain scores, and assessment of VAS pain both at rest and with activity.

Meta-analysis of the effect of extended-release epidural morphine versus intravenous patient-controlled analgesia on respiratory depression.

OBJECTIVE: Extended-release epidural morphine (EREM) is a single-dose, extended-release epidural morphine formulation intended to provide postoperative pain relief over a 48-hour period. There have been a few randomized controlled trials investigating the use and safety of EREM versus intravenous patient-controlled analgesia with opioids (IV-PCA); however, the adverse event of respiratory depression of this treatment is unclear. The authors have undertaken a meta-analysis to examine this issue. METHODS: A systematic literature search of the National Library of Medicine's PubMed database was conducted for terms related to EREM. Only randomized controlled trials, in the English language, assessing the rates of respiratory depression of EREM to IV-PCA were included for analysis. Data on pertinent study characteristics and relevant outcomes were extracted from accepted articles. Meta-analysis was performed using the Review Manager 4.2.7 (The Cochrane Collaboration, 2004). A random effects model was used. RESULTS: The authors' literature search yielded three articles which met all inclusion criteria. All studied doses of EREM were evaluated. Pooled estimates (odds ratio) were made for rates of adverse events of respiratory depression. Use of EREM was associated with significantly higher odds of respiratory depression compared to IV-PCA (odds ratio = 5.74; 95% confidence interval: 1.08, 30.54, p = 0.04). Even when examining only Food and Drug Administration approved dosages for EREM, the use of EREM was associated with significantly higher odds of respiratory depression when compared with IV-PCA (odds ratio = 5.80; 95% confidence interval: 1.05, 31.93, p = 0.04). CONCLUSIONS: Although perioperative single-dose epidural EREM (versus IV-PCA) was effective for postoperative pain relief for up to 48 hours, it is associated with significantly higher odds of respiratory depression. Further examination of the issue of respiratory depression of epidural EREM may be warranted.