Vernon H. Ross

Success of spinal and epidural labor analgesia: comparison of loss of resistance technique using air versus saline in combined spinal-epidural labor analgesia technique.

Background:Comparison of air versus saline for loss of resistance technique (LORT) in combined spinal epidural labor analgesia (CSE) has not been evaluated, and neither has the relation between CSE characteristics (the presence/absence of initial spontaneous clear fluid return or upon aspiration) and spinal/epidural analgesia outcomes. The authors hypothesized that there is no difference in the spinal analgesia success or epidural catheter efficacy between using air versus saline LORT for CSE. Methods:A total of 360 patients were randomized to air or saline LORT for CSE. Primary outcome was spinal analgesia success as defined by verbal pain score of no more than 3 at 15 min after spinal dose administration. Secondary outcomes were CSE characteristics, catheter replacement, and average hourly epidural drug consumption. Results:Results from 345 patients were analyzed. Spinal analgesia success, epidural catheter replacement, and drug consumption were not different between using air or saline LORT and were also independent of the presence/absence of fluid return on aspiration if initial spontaneous fluid returned to the spinal needle. However, epidural catheters inserted in absence of initial fluid return had a significantly higher catheter replacement rate (28.6%) than the 4.1% among those with initial fluid return (P < 0.03). Conclusions:Spinal analgesia success rate and epidural efficacy are independent of whether air or saline is used for LORT during CSE. Practice of aspiration for fluid after observing initial fluid return may be unnecessary because this practice does not alter spinal/epidural analgesia outcomes. However, epidural catheters inserted with the absence of initial fluid returned to spinal needle may pose a high failure risk.

Neostigmine Decreases Bupivacaine Use by Patient-Controlled Epidural Analgesia During Labor: A Randomized Controlled Study

BACKGROUND: Intrathecal neostigmine not only produces analgesia but also severe nausea. In contrast, epidural neostigmine enhances opioid and local anesthetic analgesia without causing nausea. Previous studies examined only single epidural neostigmine bolus administration and did not assess the efficacy of continuous epidural infusion or several aspects of maternal and fetal safety. We therefore tested the hypothesis that epidural neostigmine in combination with bupivacaine by continuous infusion during labor would reduce the amount of bupivacaine required. METHODS: Twelve healthy women scheduled for elective cesarean delivery were assigned to receive epidural neostigmine, 40 μg (first six subjects) or 80 μg (second six subjects) as a single bolus, with fetal heart rate (FHR) and uterine contractions monitored for 20 min. In a subsequent experiment, 40 healthy laboring women were randomized to receive bupivacaine 1.25 mg/mL alone or with neostigmine 4 μg/mL by patient-controlled epidural analgesia. The primary outcome measure was hourly bupivacaine use. RESULTS: Epidural neostigmine bolus did not alter baseline FHR, induce contractions, or produce nausea. Epidural neostigmine infusion reduced bupivacaine requirement by 19% in all patients and 25% in those with >4 h of treatment (P < 0.05 for both) but might have contributed to the incidence of mild sedation. Mode of delivery, incidence of maternal nausea, and FHR abnormality were similar between groups. CONCLUSIONS: These data show that adding epidural neostigmine 4 μg/mL reduces the hourly bupivacaine requirement by 19%–25% with patient-controlled epidural analgesia during labor. Administered as a bolus and by continuous infusion at the studied doses, epidural neostigmine does not cause nausea and does not induce uterine contractions or FHR abnormalities, but mild sedation can occur.

Incidence of postdural puncture headache and backache, and success rate of dural puncture: comparison of two spinal needle designs.

Objectives The goal of this randomized study was to compare the incidence of postdural puncture headache (PDPH) and postdural puncture backache (PDPB), and the success rate between two small-gauge spinal needle designs used in women undergoing subarachnoid block anesthesia. Methods After Institutional Review Board approval, 215 patients presenting for tubal ligation were randomly assigned to have 26-gauge Atraucan (AT group) or 25-gauge Whitacre (WH group) spinal needles used in their spinal anesthesia. The number of attempts to successful cerebrospinal fluid return and the success rate of the spinal blockade were documented. Postoperatively, an investigator blinded to the study interviewed patients daily. Results The incidence of PDPH was similar between the AT group (3.9%) and the WH group (4.0%). The total duration of all PDPHs was 5 days for the AT group and 15 days for the WH group. Both groups had a similar one-attempt success rate of 61% (AT group) and 62% (WH group). Failure to obtain cerebrospinal fluid occurred in only one in the AT group and two in the WH group. The incidence of PDPB was similar and the severity was mild in both groups. Conclusions The low complication and failure rates make these two types of smaller size spinal needle design good candidates for dural puncture procedures, such as spinal anesthesia, diagnostic lumbar punctures, and myelograms.

Combined Spinal Epidural Technique for Labor Analgesia Does Not Delay Recognition of Epidural Catheter Failures: A Single-center Retrospective Cohort Survival Analysis.

Background:It is unclear whether recognition of epidural catheter failures is delayed with combined spinal epidural technique (CSE) compared to traditional epidural technique (EPID) when used for labor analgesia. The authors hypothesized that recognition of failed catheters is not delayed by CSE. Methods:Anesthetic, obstetric, and quality assurance records from 2,395 labor neuraxial procedures (1,440 CSE and 955 EPID) performed at Forsyth Medical Center (Winston-Salem, North Carolina) between June 30 and December 31, 2012, were retrospectively analyzed. The primary outcome was catheter survival (failure-free) time during labor analgesia. A proportional hazards model with the counting method was used to assess relationships between the techniques and survival (failure-free) time of catheters, while controlling for subjects’ body mass index and providers’ level of training in the final best-fit multivariable regression model. Results:Cumulative incidence of epidural catheter failures was 6.6% for CSE and 11.6% for EPID (P = 0.001). In the multivariable regression model, catheters placed with CSE versus epidural were less likely to fail (hazard ratio, 0.58; 95% CI, 0.43 to 0.79; P = 0.0002) for labor analgesia. Among the catheters that failed, there was no overall difference in failure time course between the techniques (hazard ratio, 1.17; 95% CI, 0.89 to 1.54; P = 0.26) even though more failed catheters with CSE (48.4%) than with EPID (30.6%) were recognized within the first 30 min of placement (P = 0.009). Conclusions:In this cohort, CSE has a significantly lower risk of overall epidural catheter failures than EPID and does not delay recognition of epidural catheter failures. Choice of CSE versus EPID should be based on overall risk of failure, efficacy, and side effects.

Teaching neuraxial anesthesia techniques for obstetric care in a Ghanaian referral hospital: achievements and obstacles.

Anesthesia providers in low-income countries may infrequently provide regional anesthesia techniques for obstetrics due to insufficient training and supplies, limited manpower, and a lack of perceived need. In 2007, Kybele, Inc. began a 5-year collaboration in Ghana to improve obstetric anesthesia services. A program was designed to teach spinal anesthesia for cesarean delivery and spinal labor analgesia at Ridge Regional Hospital, Accra, the second largest obstetric unit in Ghana. The use of spinal anesthesia for cesarean delivery increased significantly from 6% in 2006 to 89% in 2009. By 2012, >90% of cesarean deliveries were conducted with spinal anesthesia, despite a doubling of the number performed. A trial of spinal labor analgesia was assessed in a small cohort of parturients with minimal complications; however, protocol deviations were observed. Although subsequent efforts to provide spinal analgesia in the labor ward were hampered by anesthesia provider shortages, spinal anesthesia for cesarean delivery proved to be practical and sustainable.

A randomized controlled comparison between combined spinal-epidural and single-shot spinal techniques in morbidly obese parturients undergoing cesarean delivery: time for initiation of anesthesia.

BACKGROUND:There is no current consensus on the optimal technique for subarachnoid anesthesia in morbidly obese parturients even though some providers prefer the combined spinal-epidural (CSE) over single-shot spinal (SSS) technique. In this randomized controlled study, we compared the time required for initiation of subarachnoid anesthesia between SSS and CSE techniques in morbidly obese parturients undergoing elective cesarean delivery. METHODS:Morbidly obese parturients presenting for elective cesarean delivery were randomized to receive subarachnoid anesthesia performed either with a SSS or a CSE technique. The spinal procedure in the sitting position was attempted by an experienced resident for up to 10 minutes, and if unsuccessful, the attending obstetric anesthesiologist assumed control of the procedure. The primary outcome was the time it took from the insertion of the introducer needle (SSS group) or insertion of the epidural needle (CSE group) to the end of intrathecal injection of drugs (procedure time). RESULTS:Forty-four patients were enrolled and completed the study. Three were excluded due to protocol violations. Of the remaining, 21 patients were in the SSS group and 20 in the CSE group. Demographic variables and mean (SD) body mass index (48.7 ± 7.6 kg/m2 for SSS; 49.9 ± 8.6 kg/m2 for CSE) were not different between groups. The median [interquartile range] for procedure time was 210 [116–692] seconds and 180 [75–450] seconds for SSS and CSE groups, respectively (P = 0.36), while the 95% confidence interval (CI) of the difference was −80 to +180 seconds. The first operator completed the procedure in <10 minutes in 71% of subjects in the SSS group and 95% of those in the CSE group (P = 0.09) and the 95% CI of the difference was −2% to +45%. There were more attempts to successful completion of the procedure in the SSS group (P = 0.007) with its 95% CI of the difference being +1 to +6. CONCLUSION:Our results suggest that the CSE technique is noninferior to the SS technique in morbidly obese parturients for time of initiation of subarachnoid anesthesia and may be accomplished with fewer attempts than the SSS technique with experienced residents.

Diversity in the American Society of Anesthesiologists Leadership.

BACKGROUND: Women and minorities are underrepresented in US academic medicine. The Sullivan Commission on Diversity in the Healthcare Workforce emphasized the importance of diverse leadership for reducing health care disparities. The objective of this study was to evaluate the demographics of the American Society of Anesthesiologists leadership. We hypothesized that the percentage of women and underrepresented minorities is less than that of their respective proportions in the general physician workforce. METHODS: An electronic survey was developed by the authors and mailed to 595 members of the American Society of Anesthesiologists leadership who had valid email addresses, including the members of the 2014 House of Delegates and state society leaders who were not the members of the House of Delegates. Univariate statistics were used to characterize survey responses and the probability distributions were estimated using the binomial distribution. A one-sample t test was used to compare the percentage of women and minorities in the survey pool to that of the corresponding percentages in the general physician workforce (38.0% women and 8.9% minorities), and the US population (51.0% women and 32.0% minorities). RESULTS: The survey response rate was 54%. A total of 21.1% (95% confidence interval: 16.4%–25.7%) of respondents were women and 6.0% (95% confidence interval: 3.3%–8.7%) were minorities. The proportion of women in the American Society of Anesthesiologist leadership was lower than the general medical workforce and the US population (P < .001 for both); the proportion of underrepresented minorities was lower than the US population (P < .001). CONCLUSIONS: Women and minorities are underrepresented in the leadership of the American Society of Anesthesiologists. Efforts should be made to increase the diversity of the American Society of Anesthesiologists leadership with the goal of reducing overall anesthesia workforce disparities.

Epidural Neostigmine versus Fentanyl to Decrease Bupivacaine Use in Patient-controlled Epidural Analgesia during Labor: A Randomized, Double-blind, Controlled Study

Background: The addition of opioids to epidural local anesthetic reduces local anesthetic consumption by 20% but at the expense of side effects and time spent for regulatory compliance paperwork. Epidural neostigmine also reduces local anesthetic use. The authors hypothesized that epidural bupivacaine with neostigmine would decrease total hourly bupivacaine use compared with epidural bupivacaine with fentanyl for patient-controlled epidural analgesia. Methods: A total of 215 American Society of Anesthesiologists physical status II, laboring parturients requesting labor epidural analgesia consented to the study and were randomized to receive 0.125% bupivacaine with the addition of either fentanyl (2 &mgr;g/ml) or neostigmine (2, 4, or 8 &mgr;g/ml). The primary outcome was total hourly local anesthetic consumption, defined as total patient-controlled epidural analgesia use and top-ups (expressed as milliliters of 0.125% bupivacaine) divided by the infusion duration. A priori analysis determined a group size of 35 was needed to have 80% power at &agr; = 0.05 to detect a 20% difference in the primary outcome. Results: Of 215 subjects consented, 151 patients were evaluable. Demographics, maternal and fetal outcomes, and labor characteristics were similar among groups. Total hourly local anesthetic consumption did not differ among groups (P = 0.55). The total median hourly bupivacaine consumption in the fentanyl group was 16.0 ml/h compared with 15.3, 14.6, and 16.2 ml/h in the 2, 4, and 8 &mgr;g/ml neostigmine groups, respectively (P = 0.55). Conclusions: The data do not support any difference in bupivacaine requirements for labor patient-controlled epidural analgesia whether patients receive epidural bupivacaine with 2 to 8 &mgr;g/ml neostigmine or epidural bupivacaine with 2 &mgr;g/ml fentanyl.