Choice of anaesthetic agents for caesarean section: A UK survey of current practice

Accidental Awareness Under General Anesthesia During Cesarean Section: An Observational Study

Background

A Caesarean section (CS) if performed under general anesthesia (GA) is a procedure with an increased risk of accidental awareness. This study aimed to examine the incidence of accidental awareness under GA in hospitals in the Republic of Srpska (Bosnia and Herzegovina) where GA for CS is performed in a significantly higher percentage compared to spinal anesthesia.

Methodology

In the period from 2016 to 2018, a multicenter, prospective, observational study was conducted in five medical centers in the Republic of Srpska (Bosnia and Herzegovina). The study included 1,161 patients who underwent CS. A total of 427 (36.7%) patients had elective and 734 (63.3%) had emergency CSs. The patients were surveyed postoperatively using the modified Brice questionnaire.

Results

Of the 1,161 patients included in the study, 12 (1.03%) reported memory in the period between induction and emergence of anesthesia. Five (0.43%) of them reported definite and seven (0.6%) possible and unlikely awareness. Significant psychological trauma due to pain was reported by two patients. Dreams during anesthesia were reported by 42 patients (3.61%) and five of them stated that the dreams were unpleasant.

Conclusions

Accidental awareness under GA during CS has a significant incidence in medical centers in the Republic of Srpska (Bosnia and Herzegovina). According to our findings, creating new protocols for GA when performing CS is necessary.

Resuscitation of the Obstetric Patient

Pregnancy is a time of tremendous physiologic change and vulnerability. At any point, symptoms and complications can prompt the need for emergency care, and these can range from minor to life-threatening. Emergency physicians must be prepared to treat any of these complications, in addition to rescucitating the critically ill and injured pregnant patient. To optimally care for these patients, it is paramount to be aware of the unique physiologic changes that occur during pregnancy. The focus of this review is to discuss illnesses unique to pregnancy and additional aspects of resuscitation that must be considered when caring for a critically ill pregnant patient.

Evaluation of efficacy and safety of propofol in the treatment of procedural sedation/anesthesia in neonates: A protocol for systematic review and meta-analysis

BACKGROUND

In newborns, propofol anesthesia is commonly utilized. Propofol is increasingly being shown to be effective and safe in treating procedural sedation and anesthesia in neonates. This research aims to evaluate the efficacy and safety of propofol in neonates using systematic review and meta-analysis methodologies.

METHODS

A thorough review and meta-analysis of studies on propofol anesthesia in neonates will be conducted. Conduct comprehensive searches in Web of Science, PubMed, Cochrane Library, EMBASE database, WanFang database, and Chinese biomedical literature database before May 25, 2021, to obtain published and qualified research. Two reviewers will assess the quality of the included papers and extract the data independently. Then, for meta-analysis, we will utilize RevMan 5.3 software.

RESULTS

This study will pool the data of separate trials to analyze the efficacy and safety of propofol in the treatment of procedural sedation/anesthesia in neonates.

CONCLUSION

Our findings will give strong data for determining whether propofol is an effective treatment for procedural anesthesia in neonates.

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.

Neonatal and early childhood outcomes following maternal anesthesia for cesarean section: a population-based cohort study

BACKGROUND

The fetus is vulnerable to maternal drug exposure. We determined associations of exposure to spinal, epidural, or general anesthesia on neonatal and childhood development outcomes during the first 1000 days of life.

METHODS

Population-based study of all singleton, cesarean livebirths of 24+0 to 43+6 weeks gestation between January 2007 and December 2016 in Scotland, stratified by urgency with follow-up to age 2 years. Models were adjusted for: maternal age, weight, ethnicity, socioeconomic status, smoking, drug-use, induction, parity, previous cesarean or abortion, pre-eclampsia, gestation, birth weight, and sex.

RESULTS

140 866 mothers underwent cesarean section (41.2% (57,971/140,866) elective, 58.8% (82,895/140,866) emergency) with general anesthesia used in 3.2% (1877/57,971) elective and 9.8% (8158/82,895) of emergency cases. In elective cases, general anesthesia versus spinal was associated with: neonatal resuscitation (crude event rate 16.2% vs 1.9% (adjusted RR 8.20, 95% CI 7.20 to 9.33), Apgar <7 at 5 min (4.6% vs 0.4% (adjRR 11.44, 95% CI 8.88 to 14.75)), and neonatal admission (8.6% vs 4.9% (adjRR 1.65, 95% CI 1.40 to 1.94)). Associations were similar in emergencies; resuscitation (32.2% vs 12.3% (adjRR 2.40, 95% CI 2.30 to 2.50)), Apgar <7 (12.6% vs 2.8% (adjRR 3.87, 95% CI 3.56 to 4.20), and admission (31.6% vs 19.9% (adjRR 1.20, 95% CI 1.15 to 1.25). There was a weak association between general anesthesia in emergency cases and having ≥1 concern noted in developmental assessment at 2 years (21.0% vs 16.5% (adjRR 1.08, 95% CI 1.01 to 1.16)).

CONCLUSIONS

General anesthesia for cesarean section, irrespective of urgency, is associated with neonatal resuscitation, low Apgar, and neonatal unit admission. Associations were strongest in non-urgent cases and at term. Further evaluation of long-term outcomes is warranted.

Prenatal sevoflurane exposure causes neuronal excitatory/inhibitory imbalance in the prefrontal cortex and neurofunctional abnormality in rats

The balance of excitatory and inhibitory neurons in the central nervous system is critical for maintaining brain function and sevoflurane, a general anesthetic and an GABA receptor modulator, may change the balance of excitatory and inhibitory neurons in the cortex during early brain development. Herein, we investigated whether prenatal sevoflurane exposure (PSE) disturbs cortical neuronal development and brain function. Pregnant rats at the gestational day 14.5 were subjected to sevoflurane exposure at 3.0% for 3 h and their offspring were studied thereafter. We found a significant increase of parvalbumin-positive neurons, vesicular GABA transporter (VGAT) and GAD67 expression, and GABA neurotransmitter, and a significant decrease of vesicular glutamate transporter 1 (VGLUT1) expression and glutamate in the medial prefrontal cortex (mPFC) of offspring. Pyramidal neurons showed atrophy with shorter dendrites, less branches and lower spine density visualized by Golgi stain and a decrease of excitability with the increased miniature inhibitory postsynaptic current (mIPSC) frequency and amplitude, the decreased miniature excitatory postsynaptic current (mEPSC) frequency and excitation/inhibition (E/I) ratio using whole-cell recording in offspring. There was a significant increase of inhibitory synapse in the mPFC detected by electron microscopy. Furthermore, PSE animals showed hypo-excitatory phenotype including depression-like behaviors and learning deficits. Thus, our studies provide novel evidence that PSE causes the persisted imbalance of excitatory and inhibitory neurons in the mPFC, and this is very likely the mechanisms of the sevoflurane-induced brain functional abnormalities.

General anaesthetic and airway management practice for obstetric surgery in England: a prospective, multicentre observational study

There are no current descriptions of general anaesthesia characteristics for obstetric surgery, despite recent changes to patient baseline characteristics and airway management guidelines. This analysis of data from the direct reporting of awareness in maternity patients' (DREAMY) study of accidental awareness during obstetric anaesthesia aimed to describe practice for obstetric general anaesthesia in England and compare with earlier surveys and best-practice recommendations. Consenting patients who received general anaesthesia for obstetric surgery in 72 hospitals from May 2017 to August 2018 were included. Baseline characteristics, airway management, anaesthetic techniques and major complications were collected. Descriptive analysis, binary logistic regression modelling and comparisons with earlier data were conducted. Data were collected from 3117 procedures, including 2554 (81.9%) caesarean deliveries. Thiopental was the induction drug in 1649 (52.9%) patients, compared with propofol in 1419 (45.5%). Suxamethonium was the neuromuscular blocking drug for tracheal intubation in 2631 (86.1%), compared with rocuronium in 367 (11.8%). Difficult tracheal intubation was reported in 1 in 19 (95%CI 1 in 16-22) and failed intubation in 1 in 312 (95%CI 1 in 169-667). Obese patients were over-represented compared with national baselines and associated with difficult, but not failed intubation. There was more evidence of change in practice for induction drugs (increased use of propofol) than neuromuscular blocking drugs (suxamethonium remains the most popular). There was evidence of improvement in practice, with increased monitoring and reversal of neuromuscular blockade (although this remains suboptimal). Despite a high risk of difficult intubation in this population, videolaryngoscopy was rarely used (1.9%).

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.

Thiopental versus propofol on the outcome of the newborn after caesarean section: An impact study

BACKGROUND

In 2011, the company that produced thiopental in France and in the United States stopped its marketing. Because of limited evidences, the choice of the best induction agent for caesarean section remains controversial, especially in emergency. The objective of this study was to compare the effects of propofol versus thiopental on the Apgar score of the newborn.

METHODS

Newborns delivered by elective or emergency caesarean section under general anaesthesia in a university hospital were included from January 2009 to December 2013. Two periods, according to the hypnotic drug used, were compared in this before-and-after comparative study: thiopental before May 2011 and propofol after. The primary outcome was to compare the proportion of newborns with a 5-minute Apgar Score < 7 between both groups.

RESULTS

367 newborns were enrolled, 178 in thiopental group and 189 in propofol group. Demographic and clinical characteristics were similar in both groups. The occurrence of a 5-minute Apgar Score less than 7 was not influenced by the use of propofol (OR 1.40 [CI 95% 0.90-2.20] P = 0.135). Blood gas analyses and admission's rate in neonatal intensive care unit were similar in both groups.

CONCLUSIONS

Thiopental and propofol do not appear to present significant difference in term of outcome of the newborn after caesarean section. In this situation, propofol may probably be a reliable alternative to the supply reduction of thiopental imposed by forces. Prospective studies are required to confirm the safety of propofol, particularly in the long term.

Current Practice in Obstetric Anesthesia and Analgesia in Public Hospitals of Greece: A 2016 National Survey

Aims:

This descriptive survey was to evaluate the use of regional anesthesia in obstetrics in Greek public hospitals.

Methods:

The survey was conducted between March and August 2016. A structured questionnaire was sent to 50 anesthesia departments in Greek public hospitals with obstetric units.

Results:

The response rate was 94%. Data corresponding to 9475 cesarean and 8155 vaginal deliveries were collected. Regional anesthesia was used in 69.2% of all cesareans, with single shot spinal being the most popular (44.3% of all cesareans). Combined spinal-epidural anesthesia was used in 18.1% of all cesareans (35.1% in hospitals of Athens versus 7.9% outside Athens, p<0.001). Post-cesarean analgesia was applied with simple analgesics and systematic opioids (78.6%). Long-acting spinal opioids were rarely used (4.4% of spinal and spinal/epidurals). Labor epidural analgesia was applied in 19.1% of all vaginal deliveries (30.3% in Athens versus 13.1% outside Athens, p<0.001). Paracetamol and pethidine represented the standard labor analgesics in 48.9% and 55.3% of all hospitals. Intravenous remifentanil was used in 10.6% of hospitals (50% in Athens versus 2.5% outside Athens, p=0.002). In 48.9% of hospitals, mainly outside Athens, the anesthesiologists did not get involved in labor analgesia.

Conclusion:

Regional anesthesia is the most common practice for cesareans in Greek public hospitals; however, the percentage of general anesthesia remains high. In addition, the use of labor epidural analgesia is limited in hospitals outside Athens.

A survey of practice of rapid sequence induction for caesarean section in England

BACKGROUND

In view of newer techniques of preoxygenation and laryngoscopy and recent obstetric guidelines concerning the management of difficult intubation, we aimed to evaluate the current practice of rapid sequence induction for caesarean section in England.

METHODS

In 2017, 316 questionnaire surveys were posted to all 158 hospitals with caesarean section capabilities in England. At each hospital, one questionnaire was to be completed by the obstetric anaesthetic consultant lead and one by an anaesthetic trainee. Differences in responses between consultants and trainees, regardless of their place of work, were compared for all data using the chi-square and the Fisher's exact tests.

RESULTS

One-hundred-and-eighty complete questionnaires were returned, with an overall response rate of 57%, 98 (54%) from obstetric anaesthetic consultant leads and 82 (45.6%) from trainees). Both head up (57%) and ramped (56%) were the preferred positions for preoxygenation. Less than half of respondents (43%) preoxygenated until the surgeon was scrubbed. Cricoid pressure was used by almost all respondents (98%). Thiopentone (67%) was the most commonly chosen anaesthetic induction agent and most respondents (82%) supported a change to the use of propofol. Suxamethonium (92%) was the neuromuscular blocker of choice but more than half the respondents (52%) supported a change to rocuronium. In the event of a failed intubation, the rescue supraglottic airway device of choice was the i-gel® (65%).

CONCLUSIONS

Our survey demonstrated the significant variation in the practice of rapid sequence induction for caesarean section in obstetrics in the United Kingdom.

[Application of sevoflurane and laryngeal mask in cesarean section in women with heart disease]

OBJECTIVE

To compare the safety of sevoflurane anesthesia with laryngeal mask and tracheal intubation in cesarean section in women with heart disease.

METHODS

Fifty-two pregnant women with heart diseases undergoing cesarean section were randomized into laryngeal mask (LAM) group and tracheal intubation group. In LAM group, 6% sevoflurane was given at the rate of 6 L/min for induction with a maintenance sevoflurane concentration of 3%. In the intubation group, 1.5 mg/kg propofol and 1 µg/kg remifentanil were injected intravenously, and after achieving D0 with Narcotrend monitoring, 0.9 mg/kg rocuronium was injected and intubation was performed 1 min later. The systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) were recorded in the two groups before anesthesia induction (T₀), at intubation or laryngeal mask placement (T₁), skin incision (T₂), and extubation or laryngeal mask removal (T₃). The surgery to fetal birth time, uterine incision to fetal childbirth time, drug discontinuation to awake time, and newborn Apgar scores were also recorded. Sevoflurane consumption and maternal comfort during hospitalization were compared between the two groups.

RESULTS

In LAM group, HR and MBP at T₁ and T₃ were significantly lower than those in the intubation group (P<0.05). The drug discontinuation to extubation time and to awaken time were significantly shorter in LAM group than in the intubation group (P<0.05), but the operation time and fetal child birth time were comparable between the two groups (P>0.05). The women in LAM group reported better physical and psychological comforts than those in the intubation group (P<0.05). The neonatal Apgar scores and the scores of health education, satisfaction with hospital environment and service were all similar between the two groups (P>0.05).

CONCLUSION

Sevoflurane anesthesia with laryngeal mask can achieve satisfactory anesthetic effects in cesarean section in women with heart disease.

Management of anaesthesia for elective, low-risk (Category 4) caesarean section

An increasing number of caesarean sections are being performed for both elective as well as emergency cases. Category 4 caesarean section refers to a planned elective surgery after 39 weeks of gestation at a time suitable to the mother and the maternity team. For a safe conduct of anaesthesia, the updated obstetric anaesthesia guidelines recommend administration of neuraxial anaesthesia, whenever feasible. The management should include adequate postoperative pain relief, early ambulation, and thromboprophylaxis to ensure early recovery. This review will discuss the anaesthetic management including regional anaesthesia, general anaesthesia, and postoperative analgesia for elective, low-risk (Category 4) caesarean section.

Awareness and Aortocaval Obstruction in Obstetric Anesthesia

Awareness during general anesthesia for cesarean delivery continues to be a major problem. The key to preventing awareness is strict attention to anesthetic technique. The prevalence and implications of aortocaval compression have been firmly established. Compression of the vena cava is a real occurrence when assuming the supine position. Relief of this compression most likely does not occur until the patient is turned 30°, which is not feasible for performing cesarean delivery. Although it is still wise to tilt the patient, the benefit of this tilt may not be as great as once thought.

Obstetric Anaesthetists' Association and Difficult Airway Society guidelines for the management of difficult and failed tracheal intubation in obstetrics

The Obstetric Anaesthetists' Association and Difficult Airway Society have developed the first national obstetric guidelines for the safe management of difficult and failed tracheal intubation during general anaesthesia. They comprise four algorithms and two tables. A master algorithm provides an overview. Algorithm 1 gives a framework on how to optimise a safe general anaesthetic technique in the obstetric patient, and emphasises: planning and multidisciplinary communication; how to prevent the rapid oxygen desaturation seen in pregnant women by advocating nasal oxygenation and mask ventilation immediately after induction; limiting intubation attempts to two; and consideration of early release of cricoid pressure if difficulties are encountered. Algorithm 2 summarises the management after declaring failed tracheal intubation with clear decision points, and encourages early insertion of a (preferably second-generation) supraglottic airway device if appropriate. Algorithm 3 covers the management of the 'can't intubate, can't oxygenate' situation and emergency front-of-neck airway access, including the necessity for timely perimortem caesarean section if maternal oxygenation cannot be achieved. Table 1 gives a structure for assessing the individual factors relevant in the decision to awaken or proceed should intubation fail, which include: urgency related to maternal or fetal factors; seniority of the anaesthetist; obesity of the patient; surgical complexity; aspiration risk; potential difficulty with provision of alternative anaesthesia; and post-induction airway device and airway patency. This decision should be considered by the team in advance of performing a general anaesthetic to make a provisional plan should failed intubation occur. The table is also intended to be used as a teaching tool to facilitate discussion and learning regarding the complex nature of decision-making when faced with a failed intubation. Table 2 gives practical considerations of how to awaken or proceed with surgery. The background paper covers recommendations on drugs, new equipment, teaching and training.

Initial non-opioid based anesthesia in a parturient having severe aortic stenosis undergoing cesarean section with aortic valve replacement

Pregnancy in presence of severe aortic stenosis (AS) causes worsening of symptoms needing further intervention. In the advanced stages of pregnancy, some patients may even require aortic valve replacement (AVR) and cesarean delivery in the same sitting. Opioid based general anesthesia for combined lower segment cesarean section (LSCS) with AVR has been described. However, the use of opioid may lead to fetal morbidity and need of respiratory support for the baby. We describe successful anesthetic management for LSCS with AVR in a >33 week gravida with severe AS and congestive heart failure. We avoided opioids till delivery of the baby AVR; the delivered neonate showed a normal APGAR score.