Hypnotic agents for induction of general anesthesia in cesarean section patients: A systematic review and meta-analysis of randomized controlled trials

Status epilepticus in pregnancy: a literature review and a protocol proposal

INTRODUCTION

Status epilepticus (SE) in pregnancy represents a life-threatening medical emergency for both mother and fetus. Pregnancy-related pharmacokinetic modifications and the risks for fetus associated with the use of antiseizure medications (ASMs) and anesthetic drugs complicate SE management. No standardized treatment protocol for SE in pregnancy is available to date.

AREAS COVERED

In this review, we provide an overview of the current literature on the management of SE in pregnancy and we propose a multidisciplinary-based protocol approach.

EXPERT OPINION

Literature data are scarce (mainly anecdotal case reports or small case series). Prompt treatment of SE during pregnancy is paramount and a multidisciplinary team is needed. Benzodiazepines are the drugs of choice for SE in pregnancy. Levetiracetam and phenytoin represent the most suitable second-line agents. Valproic acid should be administered only if other ASMs failed and preferably avoided in the first trimester of pregnancy. For refractory SE, anesthetic drugs are needed, with propofol and midazolam as preferred drugs. Magnesium sulfate is the first-line treatment for SE in eclampsia. Termination of pregnancy, via delivery or abortion, is recommended in case of failure of general anesthetics. Further studies are needed to identify the safest and most effective treatment protocol.

Duration of Exposure to General Endotracheal Anesthesia during Cesarean Deliveries at Term and Perinatal Complications

OBJECTIVE

To examine whether the duration of time from initiation of general endotracheal anesthesia (GETA) to delivery for cesarean deliveries (CDs) performed is related to perinatal outcomes.

STUDY DESIGN

This is a retrospective study of patients with singleton nonanomalous gestations undergoing CD ≥37 weeks of gestation under GETA with reassuring fetal status at a single tertiary care center from 2000 to 2016. Duration from GETA initiation until delivery was calculated as the time interval from GETA induction to delivery (I-D), categorized into tertiles. Outcomes for those in the tertile with the shortest I-D were compared with those in the other two tertiles. The primary perinatal outcome was a composite of complications (continuous positive airway pressure or high-flow nasal cannula for ≥2 consecutive hours, inspired oxygen ≥30% for ≥4 consecutive hours, mechanical ventilation, stillbirth, or neonatal death ≤72 hours after birth). Secondary outcomes were 5-minute Apgar score <7 and a composite of maternal morbidity (bladder injury, bowel injury, and extension of hysterotomy). Bivariable and multivariable analyses were used to compare outcomes.

RESULTS

Two hundred eighteen maternal-perinatal dyads were analyzed. They were dichotomized based on I-D ≤4 minutes (those in the tertile with the shortest duration) or >4 minutes. Women with I-D >4 minutes were more likely to have prior abdominal surgery and less likely to have labored prior to CD. I-D >4 minutes was associated with significantly increased frequency of the primary perinatal outcome. This persisted after multivariable adjustment. In bivariable analysis, 5-minute Apgar <7 was more common in the group with I-D >4 minutes, but this did not persist in multivariable analysis. Frequency of maternal morbidity did not differ.

CONCLUSION

When CD is performed at term using GETA without evidence of nonreassuring fetal status prior to delivery, I-D interval >4 minutes is associated with increased frequency of perinatal complications.

KEY POINTS

· Cesarean delivery under general anesthesia is associated with increased perinatal complications.. · Perinatal complications are increased with increasing duration of exposure to general anesthetics.. · Maternal complications were not increased with shorter duration of exposure to general anesthesia..

Perioperative management of emergent cesarean section in a patient with peripartum cardiomyopathy and orthopnea: a case report

Perioperative management of pregnant women with heart failure is difficult. Management of anesthesia in pregnant women is especially difficult because all of the currently available choices present challenges. We report a patient with peripartum cardiomyopathy (PPCM) who required an emergent cesarean section and discuss the possible tactics for managing anesthesia. A 40-year-old primipara with severe cardiac and respiratory failure required an emergent cesarean section at 39⁺¹ gestational weeks. Her left ventricular ejection fraction was between 10% and 15%, and she had orthopnea. General anesthesia was planned after inserting sheaths for percutaneous cardiopulmonary support from the femoral artery and vein. However, when the patient was asked to lie down on the operation bed, she panicked and resisted because of labor pain and dyspnea. Therefore, anesthesia was induced instead of the initial plan. Finally, we successfully managed the anesthesia and delivered the newborn. There are no alternatives to general anesthesia in patients with PPCM presenting with orthopnea. Anesthesia induction in the supine position is impossible in such patients owing to dyspnea. Anesthesia should be started with light sedation in the sitting position, and ketamine or low-dose remifentanil may be an option to maintain maternal hemodynamics and prevent neonatal asphyxia.

Adequacy of maternal anesthesia depth with two sodium thiopental doses in elective caesarean section: a randomized clinical trial

Background

Administration of an optimal dose of anesthetic agent to ensure adequate depth of hypnosis with the lowest risk of adverse effects to the fetus is highly important in cesarean section. Sodium thiopental (STP) is still the first choice for induction of anesthesia in some countries for this obstetric surgery. We aimed to compare two doses of STP with regarding the depth of anesthesia and the condition of newborn infants.

Methods

In this clinical trial, parturient undergoing elective Caesarian section were randomized into two groups receiving either low-dose (5 mg/kg) or high-dose (7 mg/kg) STP. Muscle relaxation was provided with succinylcholine 2 mg/kg and anesthesia was maintained with O2/N2O and sevoflurane. The depth of anesthesia was evaluated using isolated forearm technique (IFT) and bispectral index (BIS) in various phases. Additionally, infants were assessed using Apgar score and neurobehavioral test.

Results

Forty parturient were evaluated in each group. BIS was significantly lower in high-dose group at skin incision to delivery and subcutaneous and skin closure. Also, significant differences were noticed in IFT over induction to incision and incision to delivery. Apgar score was significantly lower in high-dose group at 1 min after delivery. Newborn infants in low-dose group had significantly better outcomes in all three domains of the neurobehavioral test.

Conclusion

7 mg/kg STP is superior to 5 mg/kg in creating deeper hypnosis for mothers. However, it negatively impacts Apgar score and neurobehavioral test of neonates. STP seems to has dropped behind as an acceptable anesthetic in Cesarean section.

Trial registration

IRCT No: 2016082819470 N45, 13/03/2019.

Neurocritical Care of the Pregnant Patient

Purpose of review

To summarize recent changes in management and emerging therapies for pregnant neurocritical care patients.

Recent findings

Diagnostic and treatment options for managing neurologic emergencies in pregnant patients have expanded with both greater understanding of the effects of imaging modalities and medications on pregnancy and application of standard treatments for non-pregnant patients to pregnant populations. Specifically, this includes cerebrovascular diseases (pregnancy-associated ischemic stroke, pregnancy-associated intracerebral hemorrhage, cerebral venous sinus thrombosis), post-maternal cardiac arrest care, seizures and status epilepticus, myasthenia gravis, and fetal somatic support in maternal death by neurologic criteria.

Summary

With the exception of direct abdominal computed tomography (CT), most imaging studies are reasonably safe in pregnancy. When emergent imaging is needed to prevent maternal morbidity or mortality, any CT sequence with or without contrast is appropriate to pursue. Though new safety data on antiplatelets, antihypertensives, thrombolytics, and antiepileptic drugs have increased options for disease management in pregnancy, unfractionated and low-molecular weight heparin remain the safest options for anticoagulation. Early studies on hypothermia, ketamine, and immunomodulating therapies in pregnancy are promising. In myasthenia gravis, new data on adjunct devices may allow more patients to undergo safe vaginal delivery, avoiding cesarean section and the associated risk of crisis. When difficult decisions regarding preterm delivery arise, recent outcome studies can help inform discussion. Lastly, when the feared complication of maternal death by neurologic criteria occurs, fetal somatic support may help to save at least one life.

Incidence and risk factors for maternal hypoxaemia during induction of general anaesthesia for non-elective Caesarean section: a prospective multicentre study

BACKGROUND

Pregnant women are at increased risk of hypoxaemia during general anaesthesia. Our aim was to determine the incidence and the risk factors that contribute to hypoxaemia in this setting.

METHODS

Every woman 18 yr or older who underwent a non-elective Caesarean section under general anaesthesia was eligible to participate in this multicentre observational study. The primary endpoint was the incidence of hypoxaemia defined as the SpO₂ ≤95%. The secondary endpoint was the incidence of difficult intubation defined as more than two attempts or failed intubation.

RESULTS

During the study period, 895 women were prospectively included in 17 maternity hospitals, accounting for 79% of women who had general anaesthesia for non-elective Caesarean section. Maternal hypoxaemia was observed in 172 women (19%; confidence interval [CI], 17-22%). Risk factors associated with hypoxaemia in the multivariate analysis were difficult or failed intubation (adjusted odds ratio [aOR]=19.1 [8.6-42.7], P<0.0001) and BMI >35 kg m^-2 (aOR=0.53 [0.28-0.998], P=0.0495). Intubation was difficult in 40 women (4.5%; CI, 3.3-6%) and failed intubation occurred in five women (0.56%; CI, 0.1-1%). In the multivariate analysis, use of a hypnotic drug other than propofol was associated with difficult or failed intubation (aOR=25 [2-391], P=0.02). A propensity score confirmed that propofol was associated with a significant decreased risk of difficulty or failure to intubate (P<0.001).

CONCLUSIONS

Hypoxaemia during Caesarean sections was observed in 19% of women and was significantly associated with difficult or failed intubation. The use of propofol may protect against the occurrence of difficult intubation.

Comparison of electroencephalogram between propofol- and thiopental-induced anesthesia for awareness risk in pregnant women

There have been few comparative studies using electroencephalogram (EEG) spectral characteristics during the induction of general anesthesia for cesarean section. This retrospective study investigated the differences in the depth of anesthesia through EEG analysis between propofol- and thiopental-induced anesthesia. We reviewed data of 42 patients undergoing cesarean section who received either thiopental (5 mg/kg) or propofol (2 mg/kg). EEG data were extracted from the bispectral index (BIS) monitor, and 10-second segments were selected from the following sections: 1) Stage I, BIS below 60 after induction; 2) Stage II, after intubation completion; 3) Stage III, end-tidal sevoflurane above 0 vol%. The risk of awareness was represented by the BIS and entropy measures. In Stage III, the thiopental group (n = 20) showed significantly higher BIS value than the propofol group (n = 22) (67.9 [18.66] vs 44.5 [20.63], respectively, p = 0.002). The thiopental group had decreased slow-delta oscillations and increased beta-oscillations as compared to the propofol group in Stages II and III (p < 0.05). BIS, spectral entropy, and Renyi permutation entropy were also higher in the thiopental group at Stages II and III (p < 0.05). In conclusion, frontal spectral EEG analysis demonstrated that propofol induction maintained a deeper anesthesia than thiopental in pregnant women.

Continuous intravenous infusion of remifentanil improves the experience of parturient undergoing repeated cesarean section under epidural anesthesia, a prospective, randomized study

Background

Unsatisfactory analgesia would occur frequently during repeated cesarean section under epidural anesthesia. The aim of this study is to observe the effects of intravenous remifentanil on maternal comfort, maternal and neonatal safety during repeated cesarean section under epidural anesthesia.

Methods

A total of 80 parturients undergoing repeated cesarean section were involved in the study. The patients were randomly divided into the intravenous remifentanil- assisted epidural group (group R) and epidural group (group E), respectively (n = 40). In group R, the remifentanil was continuously intravenously infused as an adjuvant to epidural anesthesia. In group E, 0.75% ropivacaine epidural or intravenous ketamine was administered as needed. Parturient baseline characteristics, vital signs, VAS scores, and comfort scores during surgery were recorded. Adverse effects were also recorded.

Results

A total of 80 patients were enrolled in the current study and the final analyses included 39 patients in group R and 38 patients in group E. No differences in patients’ baseline characteristics were found between the two groups (p > 0.05). Compared with group E, the comfort score was significantly higher in group R (9.1 ± 1.0 vs. 7.5 ± 1.3, p <  0.001), whereas the maximum VAS score was significantly lower in group R (1.8 ± 1.2 vs. 4.1 ± 1.0, p <  0.001). Maternal and neonatal adverse effects did not differ between the two groups during surgery (p > 0.05).

Conclusions

Continuous intravenous infusion of low-dose remifentanil can significantly improve the experience of parturients undergoing repeated cesarean section under epidural anesthesia, without noticeable maternal or neonatal adverse effects.

Trial registration

This study was pre-registered at http://www.chictr.org.cn/index.aspx (ChiCTR1800018423) on 17/09/2018.

Comparison of Effects of General Anesthesia and Combined Spinal/Epidural Anesthesia for Cesarean Delivery on Umbilical Cord Blood Gas Values: A Double-Blind, Randomized, Controlled Study

BACKGROUND The objective of this study was to analyze the effects of general anesthesia in cesarean section on the umbilical cord blood gas values and intraoperative hemodynamics of parturient women. MATERIAL AND METHODS A total of 112 parturient women who received cesarean section were eventually randomized into 2 groups, GA (general anesthesia) group (n=56), and SE (combined spinal and epidural anesthesia) group (n=56). The umbilical cord blood gas values, postpartum Apgar score, intraoperative blood loss, mean arterial pressure, heart rate, total operative time, time intervals from anesthesia to delivery and from skin incision to delivery, the incidences of adverse reactions and neonatal asphyxia, and the postoperative patient satisfaction were compared between the 2 groups. RESULTS There were no significant differences between the 2 groups in total operative time, Apgar score, neonatal asphyxia rate, umbilical arterial and venous cord blood gas values, intraoperative blood loss, and time interval from skin incision to delivery (all P˃0.05). The GA group was significantly shorter in the time interval from anesthesia to delivery than the SE group (P˂0.05). The incidences of nausea, vomiting, and chills in the GA group were significantly lower than those in the SE group (all P˂0.05). The GA group was significantly higher in postoperative patient satisfaction than the SE group (P˂0.05). CONCLUSIONS General anesthesia has little impact on the umbilical cord blood gas values and Apgar score, and ensures better hemodynamic stability in cesarean section. Moreover, general anesthesia is characterized by rapid induction and is therefore valuable for use in clinical procedures.