The Effect of Laser-Resistant Endotracheal Tube Design on Airflow Dynamics: A Benchtop and Clinical Study.

OBJECTIVE: Compare ventilation pressures of 2 endotracheal tube designs used in laser airway surgery in clinical practice and with a benchtop model to elucidate differences and understand the design elements that impact airflow dynamics. METHODS: Ventilatory and aerodynamic characteristics of the laser resistant stainless-steel endotracheal tube (LRSS-ET) design and the laser resistant aluminum-wrapped silicone endotracheal tube (LRAS-ET) design were compared. Ventilatory parameters were collected for 32 patients undergoing laser-assisted airway surgery through retrospective chart review. An in vitro benchtop simulation measured average resistance and centerline turbulence intensity of both designs at various diameters and physiological frequencies. RESULTS: Baseline patient characteristics did not differ between the 2 groups. Clinically, the median LRAS-ET peak inspiratory pressure (PIP; 21.00 cm H2O) was significantly decreased compared to LRSS-ET PIP (34.67 cm H2O). In benchtop simulation, the average PIP of the LRAS-ET was significantly lower at all sizes and frequencies. The LRSS-ET consistently demonstrated an increased resistance, although no patterns were observed in turbulence intensity data between both designs. CONCLUSION: The benchtop model demonstrated increased resistance in the LRSS-ET compared to the LRAS-ET at all comparable sizes. This finding is supported by retrospective ventilatory pressures during laser airway surgery, which show significantly increased PIPs when comparing identically sized inner diameters. Given the equivocal turbulence intensity data, these differences in resistance and pressures are likely caused by wall roughness and intraluminal presence of tubing, not inlet or outlet geometries. The decreased PIPs of the LRAS-ET should assist in following lung protective ventilator management strategies and reduce risk of pulmonary injury and hemodynamic instability to the patient.

Cesarean Delivery Outcomes for Patients with Coronavirus Disease-2019 in the USA.

INTRODUCTION: Coronavirus disease-2019 (COVID-19) may have increased morbidity and mortality in patients having Cesarean delivery (CD) in the USA. METHODS: We performed a retrospective cohort study of patients who had CD in 2020 using the national inpatient sample. After stratification by COVID-19 status, demographics, comorbidities, complications, mortality, and costs were compared. RESULTS: There were 31,444,222 hospitalizations in the USA in 2020 with a mortality rate of 2.8%. Among these, 1,453,945 patients had COVID-19 and mortality was 13.2%. There were 1,108,755 patients who had CD and 15,550 had COVID-19. Patients with COVID-19 more frequently had Medicaid and were Hispanic. Patients with COVID-19 had more comorbidities including chronic hypertension, diabetes mellitus, pre-eclampsia, and eclampsia. Mortality in CD patients with COVID-19 was 30 in 10,000 patients, while for non-COVID-19 patients, it was 1 in 10,000 patients, P < 0.001. The crude odds ratio for mortality in COVID-19 patients was 32.1 (95% confidence interval = 22.9 to 44.7), P < 0.001 and the adjusted odds ratio was 29.3 (95% confidence interval = 20.7 to 41.4), P < 0.001. CONCLUSIONS: CD patients with COVID-19 had 30-fold higher mortality before widespread vaccination was available with Hispanic and Medicaid patients disproportionately impacted. Potential explanations for this disparity include reduced access to personal protective equipment (e.g., masks) and testing, as well as socio-economic factors. Further research is needed to understand the factors that contributed to disparities in infection and clinical outcomes among obstetric patients during the COVID-19 pandemic. In future pandemics, enhanced efforts will be needed to protect economically disadvantaged women who are pregnant.

Etiology, management, and sequela of postdural puncture headache.

PURPOSE: The purpose of this article is to provide readers with a concise overview of the cause, incidence, treatment of, and sequalae of postdural puncture headaches (PDPH). Over the past 2 years, much data has been published on modifiable risk factors for PDPH, treatments for PDPH, and sequalae of PDPH particularly long-term. RECENT FINDINGS: There is emerging data about how modifiable risk factors for PDPH are not as absolute as once believed. There have been several new meta-analysis and clinical trials published, providing more data about effective therapies for PDPH. Significantly, much recent data has come out about the sequalae, particularly long-term of dural puncture. SUMMARY: Emerging evidence demonstrates that in patients who are at low risk of PDPH, needle type and gauge may be of no consequence in a patient developing a PDPH. Although epidural blood patch (EBP) remains the gold-standard of therapy, several other interventions, both medical and procedural, show promise and may obviate the need for EBP in patients with mild-moderate PDPH. Patients who endure dural puncture, especially accidental dural puncture (ADP) are at low but significant risk of developing short term issues as well as chronic pain symptoms.

Impact of timing of multimodal analgesia in enhanced recovery after cesarean delivery protocols on postoperative opioids: A single center before-and-after study.

STUDY OBJECTIVE: Enhanced recovery after cesarean delivery (ERAC) programs aim to decrease maternal morbidity and aid in maternal recovery and return to baseline. Multimodal analgesia is an important element of ERAC protocols, but no consensus exists on the timing of medication administration. We compared maternal pain outcomes following scheduled cesarean delivery with modification of the timing of administration of multimodal analgesia with non-steroidal anti-inflammatory drugs (NSAIDs) and acetaminophen. DESIGN: Before-and-after study. SETTING: Labor and delivery unit at a single academic institution. INTERVENTION: NSAIDs and acetaminophen were administered as a fixed-interval alternating regimen every 3 h for the initial ERAC group (ERAC 1) and fixed-interval combined regimen every 6 h for the modified ERAC group (ERAC 2). ERAC 1 and ERAC 2 groups were compared to historical controls (Pre-ERAC). PATIENTS: 520 women undergoing scheduled cesarean delivery (Pre-ERAC n = 179, ERAC 1 n = 179, and ERAC 2 n = 162). MEASUREMENTS: The primary outcomes were postoperative total and daily opioid utilization as measured in morphine milligram equivalents (MME). Secondary outcomes included postoperative length of stay, maximum pain scores, and racial disparities in care. MAIN RESULTS: The modified schedule of non-opioid analgesics involving combined administration (ERAC 2) versus alternating administration (ERAC 1) of multimodal analgesia resulted in decreased total postoperative opioid utilization (median = 26.3 vs 52.5 MME, Bonferroni corrected P = 0.002). Total postoperative opioid utilization among the ERAC 2 group was also significantly reduced compared to the Pre-ERAC group (median = 26.3 vs 105.0 MME, Bonferroni corrected P < 0.0001). CONCLUSIONS: Multidisciplinary teams developing or modifying ERAC protocols for scheduled cesarean delivery should consider a combined administration at fixed intervals of NSAIDs and acetaminophen throughout the hospital stay to optimize postoperative pain management.

Effect of enhanced recovery after surgery for elective cesarean deliveries on neonatal outcomes.

OBJECTIVE: To evaluate the impact of initiation of an enhanced recovery after cesarean delivery (ERAC) protocol for elective cesarean delivery (CD) on neonatal outcomes. STUDY DESIGN: We performed a retrospective analysis of elective CD at ≥39 weeks gestational age between September 2014 and August 2018 at a single institution before and after ERAC protocol implementation. Our primary outcome was composite neonatal complication rate and secondary outcome was rate of breastfeeding. We performed univariate analyses to detect differences in outcomes between the pre-ERAC and post-ERAC groups. RESULTS: We included 362 neonates born via elective CD before (n = 135) and after (n = 227) ERAC implementation. The post-ERAC group experienced fewer composite neonatal complications (33.0% vs. 47.4%, p = 0.009) and greater breastfeeding rates (80.2% vs. 67.4%, p = 0.009) compared to the pre-ERAC group. CONCLUSION: ERAC protocol implementation does not negatively impact neonates and may benefit both mother and baby.

Society for Obstetric Anesthesia and Perinatology: Consensus Statement and Recommendations for Enhanced Recovery After Cesarean.

The purpose of this article is to provide a summary of the Enhanced Recovery After Cesarean delivery (ERAC) protocol written by a Society for Obstetric Anesthesia and Perinatology (SOAP) committee and approved by the SOAP Board of Directors in May 2019. The goal of the consensus statement is to provide both practical and where available, evidence-based recommendations regarding ERAC. These recommendations focus on optimizing maternal recovery, maternal-infant bonding, and perioperative outcomes after cesarean delivery. They also incorporate management strategies for this patient cohort, including recommendations from existing guidelines issued by professional organizations such as the American College of Obstetricians and Gynecologists and the American Society of Anesthesiologists. This consensus statement focuses on anesthesia-related and perioperative components of an enhanced recovery pathway for cesarean delivery and provides the level of evidence for each recommendation.

Development and Impact of an Institutional Enhanced Recovery Program on Opioid Use, Length of Stay, and Hospital Costs Within an Academic Medical Center: A Cohort Analysis of 7774 Patients.

BACKGROUND: Enhanced Recovery (ER) is a change management framework in which a multidisciplinary team of stakeholders utilizes evidence-based medicine to protocolize all aspects of a surgical care to allow more rapid return of function. While service-specific reports of ER adoption are common, institutional-wide adoption is complex, and reports of institution-wide ER adoption are lacking in the United States. We hypothesized that ER principles were generalizable across an institution and could be implemented across a multitude of surgical disciplines with improvements in length of stay, opioid consumption, and cost of care. METHODS: Following the establishment of a formal institutional ER program, ER was adopted in 9 distinct surgical subspecialties over 5 years at an academic medical center. We compared length of stay, opioid consumption, and total cost of care in all surgical subspecialties as a function of time using a segmented regression/interrupted time series statistical model. RESULTS: There were 7774 patients among 9 distinct surgical populations including 2155 patients in the pre-ER cohort and 5619 patients in the post-ER cohort. The introduction of an ER protocol was associated with several significant changes: a reduction in length of stay in 5 of 9 specialties; reduction in opioid consumption in 8 specialties; no change or reduction in maximum patient-reported pain scores; and reduction or no change in hospital costs in all specialties. The ER program was associated with an aggregate increase in profit over the study period. CONCLUSIONS: Institution-wide efforts to adopt ER can generate significant improvements in patient care, opioid consumption, hospital capacity, and profitability within a large academic medical center.

Feasibility of Spinal Anesthesia Placement Using Automated Interpretation of Lumbar Ultrasound Images: A Prospective Randomized Controlled Trial.

BACKGROUND: This study evaluated the efficacy of spinal anesthesia administration by resident physicians when using an ultrasound system with automated neuraxial landmark detection capabilities. METHODS: 150 patients were enrolled in this trial. Anesthesiology residents placed spinals in subjects undergoing scheduled cesarean delivery using one of three techniques to identify neuraxial landmarks: palpation, ultrasound, or combined palpation and ultrasound. Ultrasound was performed using a handheld system that automatically identified neuraxial landmarks (e.g. midline, intervertebral spaces). All residents watched a 10-minute video and received 20 minutes of hands-on training prior to participating in the study. First insertion success rate was the primary end point. RESULTS: Among all patients, use of ultrasound resulted in a 11% greater first-insertion success rate (RR: 1.11 [0.85-1.47], p=0.431), a 15% reduction in needle insertions (RR: 0.85, p=0.052), and a 26% decrease in needle passes (RR: 0.74, p=0.070). In obese patients of BMI ≥ 30 kg/m2, use of ultrasound resulted in 26% greater first-insertion success rates (RR: 1.26, p=0.187), a 21% decrease in needle insertions (RR: 0.79, p=0.025), a 38% decrease in needle passes (RR: 0.62, p=0.030), and a 75% decrease in patients reporting neutral or low patient satisfaction with anesthesia administration (RR: 0.25, p=0.004). DISCUSSION: Resident anesthesiologists competently utilized the ultrasound system after receiving minimal training. Technical endpoints and patient satisfaction trended towards improvement when ultrasound was used prior to spinal placement, with stronger trends observed in obese patients. Additional study is required to fully characterize the impact of the ultrasound system on clinical efficacy.

Enhanced recovery program for minimally invasive and vaginal urogynecologic surgery.

INTRODUCTION AND HYPOTHESIS: Enhanced recovery protocols (ERPs) are evidenced-based interventions designed to standardize perioperative care and expedite recovery to baseline functional status after surgery. There remains a paucity of data addressing the effect of ERPs on pelvic reconstructive surgery patients. METHODS: An ERP was implemented at our institution including: patient counseling, carbohydrate loading, avoidance of opioids, goal-directed fluid resuscitation, immediate postoperative feeding and early ambulation. Patients undergoing elective pelvic reconstructive surgery before and after implementation of the ERP were identified in this cohort study. RESULTS: One hundred eighteen patients underwent pelvic reconstructive surgery within the ERP compared with 76 historic controls. Reductions were seen in length of hospital stay (29.9 vs. 27.9 h, p = 0.04), total morphine equivalents (37.4 vs. 19.4 mg, p < 0.01) and total intravenous fluids administered (2.7 l vs. 1.5 l, p < 0.0001). Hospital discharges before noon doubled (32.9 vs. 60.2%, p < 0.01). More patients in the ERP group ambulated on the day of surgery (17.1 vs. 73.7%, p < 0.01) and ambulated at least two times the day following surgery (34.2 vs. 72.9%, p < 0.01). No differences were seen in average pain scores (highest pain score 7.39 vs. 7.37, p = 0.95), hospital readmissions (3.9 vs. 3.4%, p = 0.84), or postoperative complications (6.58 vs. 8.47%, p = 0.79). Patient satisfaction significantly improved. ERP was not associated with an increase in 30-day total hospital costs. CONCLUSIONS: Implementation of ERP for pelvic reconstructive surgery patients was associated with a reduced length of hospital stay, improved patient satisfaction, and decreased administration of intravenous fluids and opioids without an increase in complications, readmissions, or hospital costs.

A Case Report of Recurrent Severe Peripartum Cardiomyopathy Complicated by Factor V Leiden and Multiple Endocrine Neoplasia Type 1: A Management Conundrum.

Cardiovascular disease is the leading cause of peripartum death in the United States during pregnancy. The presence of concomitant diagnoses may complicate or conflict with the management of the primary cardiovascular diagnosis and further complicate pregnancy and delivery. We describe the management of a 29-year-old, gravida 5, para 1 woman with severe peripartum cardiomyopathy during this and a previous pregnancy complicated by multiple endocrine neoplasia type and factor V Leiden thrombophilia, limiting therapeutic options and contributing to considerable perioperative management challenges.

The Effect of Ondansetron on Acute Opioid Tolerance in Patients Receiving Intrathecal Opioids Prior to Cesarean Delivery.

BACKGROUND: Multiple animal studies suggest that ondansetron ameliorates opioid-induced hyperalgesia and tolerance. In this study, we aimed to determine if the administration of ondansetron prior to spinal anesthesia would have an effect on intrathecal opioid-induced acute opioid tolerance, postoperative pain, and analgesic requirements in patients undergoing cesarean delivery with spinal anesthesia. METHODS: Eighty-six patients undergoing elective cesarean delivery were recruited and randomly allocated to receive either 8 mg intravenous ondansetron (n = 44) or placebo (n = 42) in a prospective, double-blind design. All patients received spinal anesthesia consisting of 15 mg bupivacaine, 20 µg of fentanyl, and 100 µg of preservative-free morphine. We used linear mixed-effects models to assess the difference in pain and opioid consumption in the first 24 hours after surgery between the 2 groups. RESULTS: No differences between the 2 groups were found in age, body mass index, American Society of Anesthesiologists physical status scores, duration of surgery, or sensory and motor block characteristics. There was no difference between the 2 groups in postoperative pain scores (P = 0.95) or opioid consumption (P = 0.68). CONCLUSIONS: In patients undergoing cesarean delivery under spinal anesthesia with intrathecal opioids, the administration of ondansetron prior to spinal anesthesia did not significantly affect postoperative pain scores or opioid consumption. Thus, the administration of ondansetron did not have an effect on acute opioid tolerance in our study.

Imaging Performance of a Handheld Ultrasound System With Real-Time Computer-Aided Detection of Lumbar Spine Anatomy: A Feasibility Study.

OBJECTIVES: The aim of this study was to evaluate the imaging performance of a handheld ultrasound system and the accuracy of an automated lumbar spine computer-aided detection (CAD) algorithm in the spines of human subjects. MATERIALS AND METHODS: This study was approved by the institutional review board of the University of Virginia. The authors designed a handheld ultrasound system with enhanced bone image quality and fully automated CAD of lumbar spine anatomy. The imaging performance was evaluated by imaging the lumbar spines of 68 volunteers with body mass index between 18.5 and 48 kg/m. The accuracy, sensitivity, and specificity of the lumbar spine CAD algorithm were assessed by comparing the algorithm's results to ground-truth segmentations of neuraxial anatomy provided by radiologists. RESULTS: The lumbar spine CAD algorithm detected the epidural space with a sensitivity of 94.2% (95% confidence interval [CI], 85.1%-98.1%) and a specificity of 85.5% (95% CI, 81.7%-88.6%) and measured its depth with an error of approximately ±0.5 cm compared with measurements obtained manually from the 2-dimensional ultrasound images. The spine midline was detected with a sensitivity of 93.9% (95% CI, 85.8%-97.7%) and specificity of 91.3% (95% CI, 83.6%-96.9%), and its lateral position within the ultrasound image was measured with an error of approximately ±0.3 cm. The bone enhancement imaging mode produced images with 5.1- to 10-fold enhanced bone contrast when compared with a comparable handheld ultrasound imaging system. CONCLUSIONS: The results of this study demonstrate the feasibility of CAD for assisting with real-time interpretation of ultrasound images of the lumbar spine at the bedside.

Enhanced Recovery Implementation in Major Gynecologic Surgeries: Effect of Care Standardization.

OBJECTIVE: To examine implementing an enhanced recovery after surgery (ERAS) protocol for women undergoing major gynecologic surgery at an academic institution and compare surgical outcomes before and after implementation. METHODS: Two ERAS protocols were developed: a full pathway using regional anesthesia for open procedures and a light pathway without regional anesthesia for vaginal and minimally invasive procedures. Enhanced recovery after surgery pathways included extensive preoperative counseling, carbohydrate loading and oral fluids before surgery, multimodal analgesia with avoidance of intravenous opioids, intraoperative goal-directed fluid resuscitation, and immediate postoperative feeding and ambulation. A before-and-after study design was used to compare clinical outcomes, costs, and patient satisfaction. Complications and risk-adjusted length of stay were drawn from the American College of Surgeons' National Surgical Quality Improvement Program database. RESULTS: On the ERAS full protocol, 136 patients were compared with 211 historical controls and the median length of stay was reduced (2.0 compared with 3.0 days; P=.007) despite an increase in National Surgical Quality Improvement Program-predicted length of stay (2.5 compared with 2.0 days; P=.009). Reductions were seen in median intraoperative morphine equivalents (0.3 compared with 12.7 mg; P<.001), intraoperative (285 compared with 1,250 mL; P<.001) and total intravenous fluids (-917.5 compared with 1,410 mL; P<.001), immediate postoperative pain scores (3.7 compared with 5.0; P<.001), and total complications (21.3% compared with 40.2%; P=.004). On the ERAS light protocol, 249 patients were compared with 324 historical controls and demonstrated decreased intraoperative and postoperative morphine equivalents (0.0 compared with 13.0 mg; P<.001 and 15.0 compared with 23.6 mg; P<.001) and decreased intraoperative and overall net intravenous fluids (P<.001). Patient satisfaction scores showed a marked and significant improvement on focus questions regarding pain control, nurses keeping patients informed, and staff teamwork; 30-day total hospital costs were significantly decreased in both ERAS groups. CONCLUSION: Implementation of ERAS protocols in gynecologic surgery was associated with a substantial decrease in intravenous fluids and morphine administration coupled with reduction in length of stay for open procedures combined with improved patient satisfaction and decreased hospital costs.

Evaluation of high-risk obstetric patients: a survey of US academic centers.

STUDY OBJECTIVES: Obstetric anesthesiologists commonly care for high-risk obstetric patients. However, it is unclear how obstetricians refer these patients for anesthetic evaluation and whether obstetric anesthesia clinics (OACs) are used. Our study aims were to determine the availability and characteristics of OACs at US academic obstetric centers and to evaluate how high-risk patients are referred for anesthetic evaluation. DESIGN: This is a survey study design. SETTING: University of Virginia Center for Survey Research. INTERVENTION: A survey questionnaire was constructed and electronically mailed to obstetric anesthesia directors based at hospitals with accredited anesthesia residency programs. MEASUREMENT: One hundred thirteen obstetric anesthesia directors were contacted. We asked questions about the presence and operational characteristics of OACs. These characteristics were compared between hospitals with high, medium, and low annual delivery volumes. We also inquired about how high-risk patients are referred for anesthetic evaluation. Frequencies were compared using Fisher test, with P< .05 considered as statistically significant. MAIN RESULTS: The survey response rate was 58% (n = 65). Overall, only 25 (38%) respondents indicated that their hospital operated an OAC. The proportion of hospitals with an OAC and OAC operational hours did not significantly vary according to hospital delivery volume. Among hospitals with an OAC, 24% respondents indicated that obstetricians always refer high-risk patients to the OAC. Nearly half of respondents (44%) indicated that high-risk patients usually or sometimes receive their first anesthetic evaluation during the delivery hospitalization. CONCLUSION: Our findings suggest that, among US academic centers, OACs are uncommon and the referral of high-risk patients for antenatal anesthetic evaluation is inconsistent. These findings suggest that more structured referral processes are needed to ensure that high-risk women receive anesthetic evaluation before labor or delivery.

Effects of hydroxyethyl starch 6 % (130/0.4) on blood loss during cesarean delivery: a propensity-matched analysis.

BACKGROUND: Hydroxyethyl starch is commonly used in the obstetric patient population to prevent hypotension during cesarean delivery. Evidence suggests hetastarch is associated with a dysfunction in coagulation cascade. We hypothesized that hetastarch use to prevent spinal hypotension during cesarean delivery would be associated with an increase in blood loss when compared to crystalloid use. METHODS: We performed a retrospective review of patients who underwent elective cesarean delivery under spinal anesthesia at the University of Virginia between 2011 and 2014. Data from 819 patients was used. Blood loss was the primary outcome. Propensity score-matching was used to match patients who received hetastarch (treatment group) with those who did not receive hetastarch (control group). RESULTS: Genetic matching resulted in 196 patients in the hetastarch group and 182 patients in the control group. There was no difference in estimated blood loss (p = 0.068), calculated blood loss (p = 0.720), total intraoperative fluid intake (p = 0.289), urine output (p = 0.421), Apgar 1 min (p = 0.830), Apgar 5 min (p = 0.138), phenylephrine consumption (p = 0.742), postoperative day 1 (POD1) hematocrit (p = 0.070) and POD1 platelets (p = 0.233). However, there was a statistically significant difference (but clinically irrelevant) in hematocrit difference between the day of admission and POD1 (mean difference 0.47, p = 0.024), and ephedrine consumption (mean difference 2 mg, p = 0.017) in favor of the control group. CONCLUSIONS: Our study did not find an association between increased perioperative blood loss and hetastarch use in patients presenting for elective cesarean delivery.

Does Ondansetron Modify Sympathectomy Due to Subarachnoid Anesthesia?: Meta-analysis, Meta-regression, and Trial Sequential Analysis.

BACKGROUND: Disagreement among many underpowered studies has led to an equivocal understanding of the efficacy of the 5-HT3 antagonist ondansetron in preventing the consequences of sympathectomy after subarachnoid anesthesia. The authors assessed the efficacy of ondansetron with respect to the overall quality and statistical power of the meta-analyses. METHODS: The authors used a standard and a newer method of meta-analysis, trial sequential analysis (TSA), to estimate adjusted CIs based on how much information has been accrued. They also used random-effects meta-analyses techniques, small trial bias assessment, selection models, sensitivity analyses, and the Grading of Recommendations on Assessment, Development, and Evaluation system. These results from the aforementioned techniques were compared, and importance of consideration of these factors was discussed. RESULTS: Fourteen randomized placebo-controlled trials (1,045 subjects) were identified and analyzed. By using conventional meta-analyses, the authors determined that ondansetron was associated with reduction in the incidence of hypotension (relative risk = 0.62 [95% CI, 0.46 to 0.83], P = 0.001; TSA-adjusted CI, 0.34 to 1.12; I = 60%, P = 0.002) and bradycardia (relative risk = 0.44 [95% CI, 0.26 to 0.73], P = 0.001; TSA-adjusted CI, 0.05 to 3.85; I = 0%, P = 0.84). However, the authors found indications of bias among these trials. TSAs demonstrated that the meta-analysis lacked adequate information size and did not achieve statistical significance when adjusted for sparse data and repetitive testing. The Grading of Recommendations on Assessment, Development, and Evaluation system showed that the results had low to very low quality of evidence. CONCLUSIONS: The analyses fail to confirm evidence that ondansetron reduces the incidence of hypotension and bradycardia after subarachnoid anesthesia due to the risk of bias and information sizes less than the required. As results from meta-analysis are given significant weight, it is important to carefully evaluate the quality of the evidence that is input.

Ondansetron Does Not Attenuate Hemodynamic Changes in Patients Undergoing Elective Cesarean Delivery Using Subarachnoid Anesthesia: A Double-Blind, Placebo-Controlled, Randomized Trial.

INTRODUCTION: Hypotension is the most common complication after subarachnoid anesthesia for cesarean delivery. Several therapeutic and preventive measures are used to attenuate this side effect. Serotonin receptor-blocking drugs have been suggested as one such approach. We sought to determine whether prophylactically administered intravenous ondansetron could attenuate hypotension in patients undergoing elective cesarean delivery performed under subarachnoid anesthesia. METHODS: Eighty-six patients undergoing elective cesarean delivery were recruited and randomly allocated to receive either 8 mg intravenous ondansetron (group O; n = 44) or placebo (group P; n = 42) in a prospective double-blind design. Systolic blood pressure (SBP), mean arterial pressure (MAP), diastolic blood pressure (DBP), and heart rate (HR) were measured at baseline and at 3-minute intervals from the time of initiation of subarachnoid anesthesia until delivery. Ondansetron effect on hemodynamics (SBP, DBP, MAP, and HR) was quantified and analyzed using a linear mixed effect model. RESULTS: We did not find differences in SBP (P = 0.78), MAP (P = 0.89), DBP (P = 0.82), or HR (P = 0.18) between the 2 groups during the study period. Phenylephrine requirements to treat hypotension were 350 µg (175-700 µg) in group O and 450 µg (300-700 µg) in group P (P = 0.30). The incidence of pruritus was 63% (n = 28 of 44) in group O and 56% (n = 23 of 42) in group P (difference, 0.08 [95% confidence interval, -0.23 to 0.41], P = 0.59). No difference in the incidence of nausea and vomiting or sensory level was found. CONCLUSIONS: Ondansetron premedication does not attenuate hemodynamic changes after subarachnoid anesthesia nor does it reduce the amount of vasopressor use, pruritus, or nausea and vomiting.

Perioperative lidocaine infusion reduces the incidence of post-mastectomy chronic pain: a double-blind, placebo-controlled randomized trial.

BACKGROUND: Chronic post-surgical pain (CPSP) is a not uncommon complication after mastectomy, with a reported incidence between 20% and 68%. Careful dissection, the use of minimally invasive surgical techniques, and attempts to reduce the associated inflammatory and hyperalgesic responses are suggested methods to prevent CPSP. OBJECTIVE: To determine if the use of perioperative lidocaine infusion is associated with decreased incidence of CPSP after mastectomy. STUDY DESIGN: Double-blind, placebo-controlled randomized trial. METHODS: This is a secondary analysis of data from 61 out of 71 patients who underwent mastectomy for breast cancer. Patients were randomized to either placebo (Group P; n = 27) or intravenous lidocaine (Group L; n = 34, bolus 1.5 mg/kg at induction, then infusion at 2 mg/kg/hr, up to 2 hours after the end of surgery) in a prospective double-blind design. CPSP was assessed at 6 months after surgery. Stepwise logistic regression analysis was performed to assess the efficacy of lidocaine. RESULTS: Overall 12 (20%) patients developed CPSP, 8 (30%) in the placebo group and 4 (12%) in the lidocaine group. Predictive factors for CPSP that remained significant after multivariate analysis included lidocaine (associated with a 20-fold decrease in CPSP, P = 0.013), breast implant placement (associated with a 16-fold increase in CPSP, P = 0.034), and radiotherapy (associated with a 29-fold increase in CPSP, P = 0.008). LIMITATIONS: Small sample size. CONCLUSION: Perioperative lidocaine administration was associated with a decreased incidence of CPSP, while breast implant placement and radiotherapy were associated with an increased incidence. These findings suggest a protective effect of lidocaine on CPSP development in mastectomy patients.

Anesthetic Management of Parturients With a Fontan Circulation: A Review of Published Case Reports.

Parturients with Fontan physiology provide unique and complex challenges to anesthesiologists. Such challenges include the maintenance of a perfect balance between preload, pulmonary vascular resistance, afterload, and cardiac output in a setting of a single ventricle physiology. The physiological changes of pregnancy add additional burden to an already "fragile" physiology, making the anesthetic management for labor and/or cesarean delivery even more complex. Understanding the impact of these changes on the Fontan physiology and the effect of anesthetic choices on this dyad (pregnancy-Fontan) is an imperative prior to caring for these patients. In an effort to determine how these patients are best managed for labor and/or cesarean delivery, we have reviewed the literature examining the peripartum anesthetic management of parturients with Fontan circulation and have identified 27 case reports.