Difficult and failed intubation in Caesarean general anaesthesia: a four-year retrospective review.

INTRODUCTION: General anaesthesia is associated with higher maternal morbidity and mortality when compared with regional anaesthesia, related mainly to failure of intubation, hypoxia and aspiration. The aim of this retrospective review was to define the incidence of failed and difficult intubation in parturients undergoing general anaesthesia for Caesarean delivery at a high-volume obstetric hospital in Singapore. METHODS: All parturients who underwent Caesarean delivery under general anaesthesia from 2013 to 2016 were identified and their medical records were reviewed to extract pertinent data. Difficult intubation was defined as 'requiring more than one attempt at intubation or documented as such, based on the opinion of the anaesthetist'. A failed intubation was defined as 'inability to intubate the trachea, with subsequent abandonment of intubation as a means of airway management'. RESULTS: Records of 660 Caesarean sections under general anaesthesia were extracted. The mean age of the parturients was 32.1 ± 5.5 years and the median body mass index was 27.5 (interquartile range 24.6-31.1) kg/m2. Rapid sequence induction with cricoid pressure was employed for all patients, with thiopentone and succinylcholine being administered for 91.2% and 98.1% of patients, respectively. There were 33 difficult intubations among 660 patients, yielding an incidence of 5.0%. Junior trainees performed about 90% of all intubations and 28 (84.8%) out of 33 difficult intubations. Repeat intubations were performed by senior residents/fellows (57.1%) and consultants (14.3%). No instance of failed intubation was reported. CONCLUSION: The local incidence of difficult obstetric intubation was one in 20. No failure of intubation was observed.

Interest and experience of anaesthesiology residents in doing research during residency training.

BACKGROUND AND AIMS: The SingHealth Anaesthesiology Residency Program is a 5-year postgraduate training programme whose curriculum covers clinical and academic training, through research and educational activities. This study aimed to describe the needs of the residents in promoting research participation during residency. METHODS: After obtaining ethics committee approval, we conducted an online anonymous survey among all residents in the Residency Program. The questionnaire comprised questions of demographic data, levels of research interest, areas of interest, the obstacles to research and the potential areas where help can be improved. SAS (version 9.4, 2017; SAS Institute Inc.) was used for descriptive analysis and logistic regression. RESULTS: Sixty-seven of the 79 residents (84.8%) in the Program responded with 58 (73.4%) completing the survey. Fifty-six of the 62 (90%) expressed some level of interest in research. The top two areas of research interest were clinical research and medical education research. The top obstacles to research were lack of time (due to competing clinical time and work-life balance) and lack of mentorship. The top three areas of research support needed by residents were supervised research protected time, departmental research manpower support and mentorship with topic expertise. Senior Residents were more likely to have higher research interest, self-initiated research participation and consideration for research as part of career progression, compared with junior residents. CONCLUSION: Residents faced many obstacles in doing research during residency training. Our findings also highlighted some of the needs for research support reported by the residents during their specialty training.

Automated mandatory bolus versus basal infusion for maintenance of epidural analgesia in labour.

BACKGROUND: Childbirth may cause the most severe pain some women experience in their lifetime. Epidural analgesia is an effective form of pain relief during labour and is considered to be the reference standard. Traditionally epidural analgesia has been delivered as a continuous infusion via a catheter in the epidural space, with or without the ability for the patient to supplement the analgesia received by activating a programmable pump to deliver additional top-up doses, known as patient-controlled epidural analgesia (PCEA). There has been interest in delivering maintenance analgesic medication via bolus dosing (automated mandatory bolus - AMB) instead of the traditional continuous basal infusion (BI); recent randomized controlled trials (RCTs) have shown that the AMB technique leads to improved analgesia and maternal satisfaction. OBJECTIVES: To assess the effects of automated mandatory bolus versus basal infusion for maintaining epidural analgesia in labour. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, the World Health Organization International Clinial Trials Registry Platform (WHO-ICTRP) and ClinicalTrials.gov on 16 January 2018. We screened the reference lists of all eligible trials and reviews. We also contacted authors of included studies in this field in order to identify unpublished research and trials still underway, and we screened the reference lists of the included articles for potentially relevant articles. SELECTION CRITERIA: We included all RCTs that compared the use of bolus dosing AMB with continuous BI for providing pain relief during epidural analgesia for labour in women. DATA COLLECTION AND ANALYSIS: We used the standard methodological procedures expected by Cochrane. Our primary outcomes were: risk of breakthrough pain with the need for anaesthetic intervention; risk of caesarean delivery; risk of instrumental delivery. Secondary outcomes included: duration of labour; local anaesthetic consumption. We used GRADE to assess the certainty of evidence for each outcome. MAIN RESULTS: We included 12 studies with a total of 1121 women. Ten studies enrolled healthy nulliparous women only and two studies enrolled healthy parous women at term as well. All studies excluded women with complicated pregnancies. There were variations in the technique of initiation of epidural analgesia. Seven studies utilized the combined spinal epidural (CSE) technique, and the other five studies only placed an epidural catheter without any intrathecal injection. Seven studies utilized ropivacaine: six with fentanyl and one with sufentanil. Two studies used levobupivacaine: one with sufentanil and one with fentanyl. Three used bupivacaine with or without fentanyl. The overall risk of bias of the studies was low.AMB probably reduces the risk of breakthrough pain compared with BI for maintaining epidural analgesia for labour (from 33% to 20%; risk ratio (RR) 0.60; 95% confidence interval (CI) 0.39 to 0.92, 10 studies, 797 women, moderate-certainty evidence). AMB may make little or no difference to the risk of caesarean delivery compared to BI (15% and 16% respectively; RR 0.92; 95% CI 0.70 to 1.21, 11 studies, 1079 women, low-certainty evidence).AMB may make little or no difference in the risk of instrumental delivery compared to BI (12% and 9% respectively; RR 0.75; 95% CI 0.54 to 1.06, 11 studies, 1079 women, low-certainty evidence). There is probably little or no difference in the mean duration of labour with AMB compared to BI (mean difference (MD) -10.38 min; 95% CI -26.73 to 5.96, 11 studies, 1079 women, moderate-certainty evidence). There is probably a reduction in the hourly consumption of local anaesthetic with AMB compared to BI for maintaining epidural analgesia during labour (MD -1.08 mg/h; 95% CI -1.78 to -0.38, 12 studies, 1121 women, moderate-certainty evidence). Five out of seven studies reported an increase in maternal satisfaction with AMB compared to BI for maintaining epidural analgesia for labour; however, we did not pool these data due to their ordinal nature. Seven studies reported Apgar scores, though there was significant heterogeneity in reporting. None of the studies showed any significant difference between Apgar scores between groups. AUTHORS' CONCLUSIONS: There is predominantly moderate-certainty evidence that AMB is similar to BI for maintaining epidural analgesia for labour for all measured outcomes and may have the benefit of decreasing the risk of breakthrough pain and improving maternal satisfaction while decreasing the amount of local anaesthetic needed.

Comparison of double intravenous vasopressor automated system using nexfin versus manual vasopressor bolus administration for maintenance of haemodynamic stability during spinal anaesthesia for caesarean delivery: A randomised double-blind controlled trial.

BACKGROUND: Hypotension is a common side effect of spinal anaesthesia during caesarean delivery and is associated with maternal and foetal adverse effects. We developed an updated double intravenous vasopressor automated (DIVA) system that administers phenylephrine or ephedrine based on continuous noninvasive haemodynamic monitoring using the Nexfin device. OBJECTIVE: The aim of our present study is to compare the performance and reliability of the DIVA system against Manual Vasopressor Bolus administration. DESIGN: A randomised, double-blind controlled trial. SETTING: Single-centre, KK Women's and Children's Hospital, Singapore. PATIENTS: Two hundred and thirty-six healthy women undergoing elective caesarean delivery under spinal anaesthesia. MAIN OUTCOME MEASURES: The primary outcome was the incidence of maternal hypotension. The secondary outcome measures were reactive hypertension, total vasopressor requirement and maternal and neonatal outcomes. RESULTS: The DIVA group had a significantly lower incidence of maternal hypotension, with 39.3% (46 of 117) patients having any SBP reading less than 80% of baseline compared with 57.5% (65 of 113) in the manual vasopressor bolus group (P = 0.008). The DIVA group also had fewer hypotensive episodes than the manual vasopressor bolus group (4.67 versus 7.77%; P < 0.0001). There was no difference in the incidence of reactive hypertension or the total vasopressor requirement. The DIVA group had less wobble in system performance. Maternal and neonatal outcomes were similar. CONCLUSION: The DIVA system achieved better control of maternal blood pressure after spinal anaesthesia than manual vasopressor bolus administration. TRIAL REGISTRATION: Clinicaltrials.gov identifier: NCT02277730.

Hyperbaric versus isobaric bupivacaine for spinal anaesthesia for caesarean section.

BACKGROUND: Bupivacaine is an amide local anaesthetic used in hyperbaric and isobaric forms. These are administered intrathecally into the spine to provide regional anaesthesia for caesarean section. Several trials have compared hyperbaric and isobaric bupivacaine but none have conclusively shown the benefit of either. This review was first published in 2013 and updated in 2016. OBJECTIVES: Our objectives were to:1. Determine the effectiveness of hyperbaric bupivacaine compared to isobaric bupivacaine for spinal anaesthesia in women undergoing caesarean section;2. Determine the safety of hyperbaric bupivacaine compared to isobaric bupivacaine for spinal anaesthesia in women undergoing caesarean section. SEARCH METHODS: We originally searched the following databases to January 2011: CENTRAL, MEDLINE and Embase.For this update, we reran our search in the above databases from January 2011 to March 2016; two studies are awaiting a response from authors for assessment and will be dealt with when we next update the review.We imposed no language restriction. SELECTION CRITERIA: We included all randomized controlled trials (RCTs) involving parturients undergoing spinal anaesthesia for elective caesarean section that compared the use of hyperbaric with isobaric bupivacaine. DATA COLLECTION AND ANALYSIS: Two authors independently extracted the data. The data that were extracted included the number of events and the sample sizes in both the intervention and control groups. For continuous outcomes, we extracted mean and standard deviation.We reported odds ratios (ORs) and risk ratios (RRs) for binary outcomes, and mean differences (MDs) for continuous outcomes. MAIN RESULTS: We included three new RCTs in this update, which now comprises 10 studies with a total of 614 participants. We judged most trials as having uncertain risk of bias regarding randomization. Other than this, the overall risk of bias was low. Most included trials had small sample sizes. All of the trials assessed the primary outcome of conversion to general anaesthesia. Ten trials comparing anaesthesia performed with hyperbaric and isobaric bupivacaine failed to show any difference in need for conversion to general anaesthesia (RR 0.33, 95% CI 0.09 to 1.17, 614 participants, very low quality of evidence). Nine trials also failed to show a difference in the need for supplemental analgesics (RR 0.61, 95% CI 0.26 to 1.41, 554 participants, very low quality of evidence). Four trials comparing requirement for ephedrine did not show any difference (RR 0.89, 95% CI 0.57 to 1.38, 256 participants, very low quality of evidence). Seven trials did not provide convincing evidence of difference in nausea and vomiting (RR 0.99, 95% CI 0.57 to 1.72, 433 participants, low quality of evidence). Three trials failed to show a difference in headache (OR 1.82, 95% CI 0.47 to 6.99, 234 participants, low quality of evidence). Two trials showed that the time until sensory block to the thoracic 4th (T4) spinal level was shorter with hyperbaric bupivacaine (MD -1.06 minutes, 95% CI -1.80 to -0.31, 128 participants, moderate quality of evidence). Six trials showed no difference in the amount of ephedrine used (RR 0.23, 95% CI -1.65 to 2.12, 386 participants, moderate quality of evidence). Three trials failed to show any difference in high block (RR 0.88, 95% CI 0.16 to 4.90, 205 participants). AUTHORS' CONCLUSIONS: Data are limited for some of the outcomes. Reporting of the included trials is less than optimal. For these reasons the overall quality of evidence is low or very low for most of the outcomes, based on the GRADE method of assessment. This review found that intrathecal hyperbaric bupivacaine had a more rapid onset of sensory blockade at the 4th thoracic vertebra (T4) level than isobaric bupivacaine. Hower, despite incorporating more data in the analysis, we found little evidence that the need for conversion to general anaesthesia and supplemental analgesia differed between the hyperbaric or isobaric bupivacaine groups. This is mainly due to the rarity of these outcomes, variability in the dose, use of adjuvant drugs and differences in the technique used for regional anaesthesia. There were no differences in the adverse effects studied. Any possible advantage of hyperbaric bupivacaine needs to be confirmed in larger randomized trials. In future research, criteria for conversion to general anaesthesia need to be defined objectively and applied uniformly.

Incidence and characteristics of breakthrough pain in parturients using computer-integrated patient-controlled epidural analgesia.

INTRODUCTION: The computer-integrated patient-controlled epidural analgesia (CIPCEA) system can automatically adjust the background infusion rate during combined spinal-epidural analgesia based on the parturient's need, as labor progresses. OBJECTIVES: The objective is to identify risk factors associated with breakthrough pain during labor as well as identify obstetric and fetal outcomes that are affected by breakthrough pain. DESIGN: This is a retrospective review of prospectively collected data. SETTING: The setting is in a delivery room. PARTICIPANTS: The participants are 280 nulliparous women in early labor (≤5 cm cervical dilatation) who received combined spinal-epidural analgesia with CIPCEA. INTERVENTIONS: The intervention is CIPCEA. MEASUREMENTS: The primary outcome is the incidence of breakthrough pain (≥1 episodes of pain or pressure that required supplemental epidural medications) during labor. Relevant demographic, anesthetic, obstetric, and fetal characteristics were also measured. Univariate and multivariate analyses were performed to identify obstetric and anesthetic factors that were associated with increased incidence of breakthrough pain as well as to evaluate the impact of breakthrough pain on obstetric and fetal outcomes. RESULTS: The incidence of breakthrough pain was 9.6%. Independent factors associated with incidence of breakthrough pain are the presence of dysfunctional labor, increased maternal body mass index, and decreased successful-to-total-bolus-demand ratio. The postlabor characteristics independently associated with breakthrough pain were increased duration of labor, decreased duration of effective analgesia, increased total local anesthetic consumption, and decreased maternal satisfaction. CONCLUSIONS: Low successful to total patient demand bolus ratio was the factor with the strongest association with breakthrough pain. Breakthrough pain was also associated with dysfunctional labor and poorer maternal satisfaction.

Comparison of computer-integrated patient-controlled epidural analgesia with no initial basal infusion versus moderate basal infusion for labor and delivery: A randomized controlled trial.

BACKGROUND AND AIMS: Computer-integrated patient-controlled epidural analgesia (CIPCEA) is a novel epidural drug delivery system. It automatically adjusts the basal infusion based on the individual's need for analgesia as labor progresses. MATERIALS AND METHODS: This study compared the time-weighted local anesthetic (LA) consumption by comparing parturients using CIPCEA with no initial basal infusion (CIPCEA0) with CIPCEA with initial moderate basal infusion of 5 ml/H (CIPCEA5). We recruited 76 subjects after ethics approval. The computer integration of CIPCEA titrate the basal infusion to 5, 10, 15, or 20 ml/H if the parturient required respectively, one, two, three, or four patient demands in the previous hour. The basal infusion reduced by 5 ml/H if there was no demand in the previous hour. The sample size was calculated to show equivalence in LA consumption. RESULTS: The time-weighted LA consumption between both groups were similar with CIPCEA0 group (mean [standard deviation (SD)] 8.9 [3.5] mg/H) compared to the CIPCEA5 group (mean [SD] 9.9 [3.5] mg/H), P = 0.080. Both groups had a similar incidence of breakthrough pain, duration of the second stage, mode of delivery, and patient satisfaction. However, more subjects in the CIPCEA0 group required patient self-bolus. There were no differences in fetal outcomes. DISCUSSION: Both CIPCEA regimens had similar time-weighted LA consumption and initial moderate basal infusion with CIPCEA may not be required.

Early versus late initiation of epidural analgesia for labour.

BACKGROUND: Pain during childbirth is arguably the most severe pain some women may experience in their lifetime. Epidural analgesia is an effective form of pain relief during labour. Many women have concerns regarding its safety. Furthermore, epidural services and anaesthetic support may not be available consistently across all centres. Observational data suggest that early initiation of epidural may be associated with an increased risk of caesarean section, but the same findings were not seen in recent randomised controlled trials. More recent guidelines suggest that in the absence of a medical contraindication, maternal request is a sufficient medical indication for pain relief during labour. The choice of analgesic technique, agent, and dosage is based on many factors, including patient preference, medical status, and contraindications. There is no systematically reviewed evidence on the maternal and foetal outcomes and safety of this practice. OBJECTIVES: This systematic review aimed to summarise the effectiveness and safety of early initiation versus late initiation of epidural analgesia in women. We considered the obstetric and fetal outcomes relevant to women and side effects of the treatments, including risk of caesarean section, instrumental birth and time to birth. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (12 February 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2014, Issue 1), MEDLINE (January 1966 to February 2014), Embase (January 1980 to February 2014) and reference lists of retrieved studies. SELECTION CRITERIA: We included all randomised controlled trials involving women undergoing epidural labour analgesia that compared early initiation versus late initiation of epidural labour analgesia. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion, extracted the data and assessed the trial quality. Data were checked for accuracy. MAIN RESULTS: We included nine studies with a total of 15,752 women.The overall risk of bias of the studies was low, with the exception of performance bias (blinding of participants and personnel).The nine studies showed no clinically meaningful difference in risk of caesarean section with early initiation versus late initiation of epidural analgesia for labour (risk ratio (RR) 1.02; 95% confidence interval (CI) 0.96 to 1.08, nine studies, 15,499 women, high quality evidence). There was no clinically meaningful difference in risk of instrumental birth with early initiation versus late initiation of epidural analgesia for labour (RR 0.93; 95% CI 0.86 to 1.01, eight studies, 15,379 women, high quality evidence). The duration of second stage of labour showed no clinically meaningful difference between early initiation and late initiation of epidural analgesia (mean difference (MD) -3.22 minutes; 95% CI -6.71 to 0.27, eight studies, 14,982 women, high quality evidence). There was significant heterogeneity in the duration of first stage of labour and the data were not pooled.There was no clinically meaningful difference in Apgar scores less than seven at one minute (RR 0.96; 95% CI 0.84 to 1.10, seven studies, 14,924 women, high quality evidence). There was no clinically meaningful difference in Apgar scores less than seven at five minutes (RR 0.96; 95% CI 0.69 to 1.33, seven studies, 14,924 women, high quality evidence). There was no clinically meaningful difference in umbilical arterial pH between early initiation and late initiation (MD 0.01; 95% CI -0.01 to 0.03, four studies, 14,004 women, high quality evidence). There was no clinically meaningful difference in umbilical venous pH favouring early initiation (MD 0.01; 95% CI -0.00 to 0.02, four studies, 14,004 women, moderate quality evidence). AUTHORS' CONCLUSIONS: There is predominantly high-quality evidence that early or late initiation of epidural analgesia for labour have similar effects on all measured outcomes. However, various forms of alternative pain relief were given to women who were allocated to delayed epidurals to cover that period of delay, so that is it hard to assess the outcomes clearly. We conclude that for first time mothers in labour who request epidurals for pain relief, it would appear that the time to initiate epidural analgesia is dependent upon women's requests.

A comparison between remifentanil and meperidine for labor analgesia: a systematic review.

BACKGROUND: Remifentanil is an ultrashort-acting opioid with favorable pharmacokinetic properties that make it suitable as a labor analgesic. Although it crosses the placenta freely, it is eliminated quickly in the neonate by rapid metabolism and redistribution. We aimed to determine whether remifentanil compared with meperidine is effective in reducing pain scores in laboring parturients. Other effects on the mother, the labor process, and the neonate were also examined. METHODS: MEDLINE, CINAHL, Embase, Cochrane CENTRAL, and Maternity and Infant Care databases were searched without language restriction using multiple keywords for labor analgesia, remifentanil, and meperidine. Published abstracts from 5 key research meetings and references from retrieved articles were examined for additional studies. Randomized controlled trials in laboring parturients comparing remifentanil with meperidine were selected. Risk of bias was assessed using criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions. We assessed for adequacy of sequence generation, allocation concealment, blinding, and completeness of follow-up. Data were extracted from each study using a standardized data collection form. The primary outcome was reduction in pain scores (visual analog scale [VAS], 0-100 mm). We also evaluated maternal side effects (sedation, oxygen desaturation, and bradypnea) and effects on the neonate (Apgar scores, umbilical cord pH, and Neurologic and Adaptive Capacity Scores). RESULTS: Seven studies (349 patients) were identified for inclusion; only 3 studies were suitable for quantitative synthesis in a meta-analysis (233 patients). We found that remifentanil reduces the mean VAS score at 1 hour by 25 mm more than meperidine (P < 0.001) (95% confidence interval = 19-31 mm). Limited conclusions can be made regarding the side-effect profile of remifentanil because of insufficient data. CONCLUSION: Compared with meperidine, remifentanil is superior in reducing mean VAS scores for labor pain after 1 hour.