Maternal and fetal outcomes following unplanned conversion to general anesthetic at elective cesarean section

Risk factors for conversion to general anesthesia for urgent cesarean among women with labor epidural analgesia: A retrospective case-control study

OBJECTIVES

General anesthesia for cesarean is associated with an increased risk of maternal morbidity compared with neuraxial anesthesia. Reducing the rate of general anesthesia for urgent cesarean in women with epidural analgesia may improve maternal outcomes. Our objective was to identify the rate and factors associated with the conversion to general anesthesia for urgent cesarean among women with labor epidural analgesia.

STUDY DESIGN

We performed a retrospective case-control study including singleton-laboring women with epidural analgesia who delivered after 37 gestational weeks by urgent cesarean (Port Royal Maternity unit, 2012-2017). Cases were all women who required conversion from neuraxial analgesia to general anesthesia. Controls were women just before and after each case included. Factors associated with the conversion to general anesthesia were identified using logistic regression analysis.

RESULTS

Among 3,300 laboring women with an epidural analgesia who delivered by urgent cesarean during the study period, 113 (3.4%,) had a conversion to general anesthesia. Factors associated with conversion to general anesthesia were a cervical dilation ≥ 5 cm at the time of epidural placement (aOR 2.55, 95%CI 1.05-6.21), asymmetric sensory blockade (aOR 3.39, 95%CI 1.11-10.36), need for ≥2 rescue top-ups (aOR 2.88, 95%CI 1.29-6.44), and category 1 cesarean (aOR 3.61, 95%CI 1.77-7.33).

CONCLUSION

Among women with labor epidural analgesia, suboptimal analgesia significantly increased the risk for conversion to general anesthesia for urgent cesarean. Epidural placement without delay during labor, regular checks of epidural analgesia efficiency, and epidural replacement in case of inadequate epidural analgesia may decrease the rate of avoidable general anesthesia for urgent cesarean.

Total failure of spinal anesthesia for cesarean delivery, associated factors, and outcomes: A retrospective case-control study

Spinal anesthesia is the anesthetic technique of choice for patients undergoing cesarean delivery. In the present study, total spinal anesthesia failure was defined as a case when an absent blockade or inadequate surgery required general anesthesia administration with an endotracheal tube. This study aimed to investigate factors related to this condition and report its maternal and neonatal outcomes. This retrospective matched case-control study was conducted by recruiting 110 patients with failed spinal anesthesia and 330 control patients from September 1, 2016, to April 30, 2020, in the largest university hospital, Thailand. Of 12,914 cesarean deliveries, 12,001 patients received single-shot spinal anesthesia (92.9%) during the study period. Total spinal anesthesia failure was experienced by 110/12,001 patients, giving an incidence of 0.9%. Factors related to the failures were a patient body mass index (BMI) ≤29.5 kg/m2 (adjusted odds ratio 1.9; 95% confidence interval 1.2-3.1; P = .010) and a third-year resident (the most senior trainee) performing the spinal block (adjusted odds ratio 2.4; 95% confidence interval 1.5-3.7; P < .001). In the group with failed spinal anesthesia, neonatal Apgar scores at 1 and 5 minutes were lower than those of the control group (both P < .001). Two patients in the failed spinal anesthesia group (2/110; 1.8%) had difficult airways and desaturation. Independent factors associated with total spinal anesthesia failure were a BMI of ≤29.5 kg/m2 and a third-year resident performing the spinal block. Although the incidence of total failure was infrequent, there were negative consequences for the mothers and neonates. Adjusting the dose of bupivacaine according to the weight and height of a patient is recommended, with a higher dose appropriate for patients with a lower BMI.

Pharmacokinetics a>nd Tolerability of Intraperitoneal Chloroprocaine After Fetal Extraction in Women Undergoing Cesarean Delivery

BACKGROUND

Intraperitoneal chloroprocaine has been used during cesarean delivery to supplement suboptimal neuraxial anesthesia for decades. The short in vitro half-life of chloroprocaine (11-21 seconds) has been cited to support the safety of this approach. However, there are no data regarding the rate of absorption, representing patient drug exposure, through this route of administration. Accordingly, we designed a study to determine the in vivo half-life of intraperitoneal chloroprocaine and assess clinical tolerability.

METHODS

We designed a single-center, prospective, cohort, multiple-dose escalation study of women 18 to 50 years of age undergoing cesarean delivery with spinal anesthesia. Chloroprocaine (40 mL) was administered after delivery of the newborn and before uterine closure. The first cohort (n = 5) received 1%, the second cohort (n = 5) received 2%, and the third cohort (n = 5) received 3% chloroprocaine solution. Maternal blood samples were obtained before administration and 1, 5, 10, 20, and 30 minutes after dosing. The primary objective was to define the pharmacokinetic profile of intraperitoneal chloroprocaine, including in vivo half-life. The secondary objective was to evaluate tolerability through determination of peak plasma concentration and prospective assessment for local anesthetic systemic toxicity.

RESULTS

The peak plasma concentration occurred 5 minutes after intraperitoneal administration in all 3 cohorts: 64.8 ng/mL (6.5 µg/kg), 28.7 ng/mL (2.9 µg/kg), and 799.2 ng/mL (79.9 µg/kg) for 1%, 2%, and 3% chloroprocaine, respectively. The in vivo half-life of chloroprocaine after intraperitoneal administration was estimated to be 5.3 minutes (95% confidence interval, 4.0-6.6). We did not detect clinical signs of local anesthetic systemic toxicity in any of the 3 cohorts.

CONCLUSIONS

The in vivo half-life of intraperitoneal chloroprocaine (5.3 minutes) is more than an order of magnitude greater than the in vitro half-life (11-21 seconds). However, maximum plasma concentrations of chloroprocaine (Cmax range, 0.05-79.9 µg/kg) were not associated with local anesthetic systemic toxicity and remain well below our predefined safe level of exposure (970 µg/kg) and levels associated with clinical symptoms (2.6-2.9 mg/kg). Therefore, our study suggests that intraperitoneal chloroprocaine, in a dosage ≤1200 mg, administered after fetal extraction, is well tolerated during cesarean delivery.

Predictors of adverse neonatal outcome in pregnancies complicated by placenta previa

INTRODUCTION

We aimed to underline the determinants of adverse neonatal outcome in gestations complicated by placenta previa (PP).

METHODS

A retrospective study including all women diagnosed with placenta previa carrying a singleton gestation who delivered between 2011 and June 2019. Gestations with adverse neonatal outcomes were compared to those without. In a secondary analysis, we further studied the rate of Placenta accreta spectrum (PAS) in relation to number of previous cesarean deliveries.

RESULTS

Overall, 548/84,558 (0.6%) singleton deliveries were complicated by PP (0.6%). PAS was noted in 105 (19.2%) cases. After exclusion of PAS cases, adverse neonatal outcome occurred in 149/443 (33.6%), median gestational age of delivery was 37 ^0/7 with a median birthweight of 2780 g. In a univariate analysis, adverse neonatal outcome was associated with emergent delivery and general anesthesia [56.8% vs. 20.8%, OR 5.00 (95% CI) 3.24-7.72, p < 0.001 and 54.4% vs. 24.8%, OR 3.60 (95% CI) 2.37-5.47, p < 0.001, respectively]. Gestational age at delivery was lower in the adverse outcome group (mean 35 ^1/7 vs. 37 ^3/7, p < 0.001). In a multivariate regression analysis, general anesthesia and gestational age at delivery were independently associated with adverse neonatal outcome [adjusted odds ratio (aOR) 2.26 (95% CI) 1.18-4.31, p = 0.01, aOR 1.10 (95% CI) 1.05-1.16, p < 0.001. Analysis of the rate of PAS among women with previous cesarean delivery and PP revealed that no cases of PAS were noted when no prior cesarean delivery was present. The rate of PAS for previous 1, 2, 3, 4 and 5 cesarean deliveries was 26.7%, 43.5%, 65.5%, 55.6% and 66.7% respectively.

DISCUSSION

Efforts should be made to avoid general anesthesia in deliveries of PP.

Enhanced recovery after cesarean delivery: a challenge for anesthesiologists

Enhanced recovery after cesarean (ERAC) delivery is an evidence-based, multi-disciplinary approach throughout pre-, intra-, post-operative period. The ultimate goal of ERAC is to enhance recovery and improve the maternal and neonatal outcomes. This review highlights the role of anesthesiologist in ERAC protocols. This review provided a general introduction of ERAC including the purposes and the essential elements of ERAC protocols. The tool used for evaluating the quality of ERAC (ObsQoR-11) was discussed. The role of anesthesiologist in ERAC should cover the areas including management of peri-operative hypotension, prevention and treatment of intra- and post-operative nausea and vomiting, prevention of hypothermia and multi-modal peri-operative pain management, and active pre-operative management of unplanned conversion of labor analgesia to cesarean delivery anesthesia. Although some concerns still remain, ERAC implementation should not be delayed. Regular assessment and process improvement should be imbedded into the protocol. Further high-quality studies are warranted to demonstrate the effectiveness and efficacy of the ERAC protocol.

Preoperative moderate thrombocytopenia is not associated with increased blood loss for low-risk cesarean section: a retrospective cohort study

BACKGROUND

The occurrence of thrombocytopenia is as high as 7-12% in pregnancy, yet minimum platelet count safe for cesarean section remains unknown.

METHODS

In this retrospective noninferior cohort study, we consecutively included patients undergoing cesarean section for a period of 6 years in a tertiary hospital and excluded patients at very high risk for excessive hemorrhage. The included patients with preoperative platelet count of 50-100 × 10⁹/L were defined as the thrombocytopenic group. The control group were eligible patients with preoperative platelet count>150 × 10⁹/L, matched to the thrombocytopenic group by age and operation timing in a 1:2 ratio. Mixed effect model was used to analyze the effect of thrombocytopenia based on a noninferiority assumption. The predefined noninferiority delta of bleeding was 50 mL.

RESULTS

There was no significant difference of the calculated blood loss between the thrombocytopenic and the control group (mean difference = 8.94, 95% CI - 28.34 mL to 46.09 mL). No statistical difference was observed in the requirement for blood transfusion, visually estimated blood loss, or the incidence of adverse events between groups. Although there were more patients admitted to intensive care unit (odds ratio = 12, 95% CI 2.69-53.62, p = 0.001) in the thrombocytopenic group, most of them required critical care for reasons other than hemorrhage. The thrombocytopenic group had longer length of hospital stay (mean difference = 0.40 days, 95% CI 0.09-0.71, p = 0.011), but the difference was considered as clinically insignificant.

CONCLUSIONS

Preoperative moderate thrombocytopenia is not associated with increased blood loss, blood transfusion, or occurrence of adverse events in patients undergoing cesarean section in absence of additional bleeding risk.