Complications in obstetric anaesthesia

Anaesthetic considerations for impacted fetal head at caesarean delivery: a focused review

BACKGROUND

Impacted fetal head occurs when the fetal head is deeply engaged within the maternal pelvis and difficult to deliver during caesarean delivery. In order to deliver the fetal head, additional surgical manoeuvres and/or pharmacological tocolysis are needed. The aim of this focused review is to outline the incidence, risk factors, management and complications of this obstetric emergency from the perspective of the anaesthetist.

METHODS

Databases were searched for free text headings and subject headings associated with different permutations of terms related to impacted fetal head and caesarean delivery.

RESULTS

Impacted fetal head has been estimated to occur in 1.5 % of elective caesarean deliveries and 2.9-18.4% of all emergency caesarean deliveries at any cervical dilatation. Risk factors include advanced cervical dilatation, labour augmentation with oxytocin, prolonged second stage of labour, fetal malposition and junior grade of operating obstetrician. If impacted fetal head occurs, the anaesthetist in conjunction with the multidisciplinary team should consider decreasing the height of the operating table, providing a step for the obstetrician to stand on, placing the patient in the head down position, providing pharmacological tocolysis with glyceryl trinitrate (or nitroglycerin), beta-2 adrenoreceptor agonists or volatile anaesthetic agents, and managing complications such as postpartum haemorrhage.

CONCLUSION

Impacted fetal head is an obstetric emergency that the anaesthetist should be familiar with and has a vital role in managing. We propose an algorithm for management that may serve as a clinical decision aid.

Median effective dose of spinal ropivacaine in combined spinal and epidural anesthesia for emergency cesarean delivery following failed vaginal delivery with epidural labor analgesia: a single-blind, sequential dose-finding study

PURPOSE

This study aimed to estimate the median effective dose of intrathecal isobaric ropivacaine without opioid required for adequate cesarean delivery anesthesia after epidural labor analgesia.

METHODS

Patients aged 20-40 years with American Society of Anesthesiology scores of I-II, body mass index ≤ 36, who underwent emergency cesarean delivery after failed vaginal delivery with epidural analgesia of a duration ≤ 6 h were included in the study. After removal of the epidural used for labor analgesia, a new combined spinal epidural was performed, and a dose of intrathecal isobaric ropivacaine without opioid was administered. The dose was determined using up-down methodology, with the starting patient's dose set to 12 mg. Adequate anesthesia, defined as a pinprick level no lower than T6 at 5 min after ropivacaine administration, resulted in the next patient receiving a dose of ropivacaine 1 mg higher, and inadequate anesthesia 1 mg lower. The primary outcome was the median (95% confidence interval (CI)) dose of spinal ropivacaine required for adequate cesarean delivery anesthesia.

RESULTS

Of the 46 patients included in the study, 40 were analyzed. The median spinal ropivacaine dose was 8.11 mg (95% CI 7.29-8.93 mg) by the Dixon and Mood method and 8.06 mg (95% CI 6.93-9.00 mg) by isotonic regression. Two patients had high spinal anesthesia.

CONCLUSION

Our findings suggest that for 50% of patients undergoing cesarean delivery after failed vaginal delivery with epidural analgesia, an 8-mg spinal dose of isobaric ropivacaine without opioid provides an anesthesia level no lower than T6 at 5 min.

Unintended subdural anesthesia and subdural air bubbles after attempted epidural anesthesia in a patient undergoing cesarean section

BACKGROUND

Unintended subdural anesthesia accompanied by air bubbles compressing the cauda after attempting epidural anesthesia is rare.

CASES

A 41-year-old pregnant woman was scheduled to undergo epidural anesthesia for cesarean section. After attempting epidural anesthesia, she experienced prolonged hypotension and recovery time, especially in the right extremity. Through magnetic resonance imaging we found subdural air bubbles compressing the right side of the cauda equina in the L3 region. Thus, we considered unintended subdural anesthesia and performed conservative management with close observation. Her symptoms completely resolved within 24 h.

CONCLUSIONS

Here, we report a case with various features of subdural anesthesia and subdural air bubbles compressing the cauda.

Comparison of the effect of dexmedetomidine intrathecal injection and intravenous infusion on subarachnoid blockade during knee arthroscopy procedures: a randomized controlled trial

BACKGROUND

Comparison of whether intrathecal dexmedetomidine prolongs spinal anesthesia-associated sensorimotor blockade more than intravenous infusion during knee arthroscopy procedures performed under subarachnoid blockade.

METHODS

Ninety patients aged 18-75 years, ASA class I-II, who underwent knee arthroscopy between October 2022 and April 2023 were randomized into intrathecal、intravenous and control groups.Subjects received three modes of administration: an intrathecal group (2 ml of 1% ropivacaine + 1 ml of 5 μg dexmedetomidine, along with intravenous saline infusion), an intravenous group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, with dexmedetomidine pumped intravenously at a dose of 0.5 μg/kg/h), and a control group (intrathecal 2 ml of 1% ropivacaine + 1 ml of 0.9% saline, along with intravenous saline infusion). Total analgesic duration, duration of sensory and motor blockade, Ramsay sedation score, Visual Analogue Score (VAS) at different postoperative time points, and occurrence of adverse effects were recorded.

RESULTS

The total analgesia duration was significantly longer in the intrathecal group than in the intravenous and control groups (352.13 ± 51.70 min VS 273.47 ± 62.57 min VS 241.41 ± 59.22 min, P < 0.001).The onset of sensory block was shorter in the intrathecal group than in the intravenous and control groups (4 [3-4]min VS 5 [4-5]min VS 5 [4-5]min; P < 0.001);the onset of motor block was shorter in the intrathecal group than in the intravenous group and the control group (5 [4-5]min VS 5 [5-6]min VS 6[5.5-7]min; P < 0.001).Sedation scores were higher in the intravenous group than in the intrathecal and control groups (P < 0.001). At 5 h postoperatively, the VAS score in the intrathecal group was lower than that in the intravenous and control groups (P < 0.001). At 24 h postoperatively, the VAS score in the intrathecal group was lower than that in the control group (P < 0.001). In addition, the incidence of bradycardia was significantly higher in the intravenous group than in the intrathecal and control groups (30%, 6.5%, and 3.4%, respectively; P = 0.018, P = 0.007).

CONCLUSIONS

Intrathecal administration of dexmedetomidine did prolong the total analgesia duration, as well as accelerate the onset of sensory-motor blockade compared with intravenous infusion, and did not result in any hemodynamic instability or other adverse events at the doses studied.

TRIAL REGISTRATION

This single-center, prospective, RCT has completed the registration of the Chinese Clinical Trial Center at 26/09/2023 with the registration number ChiCTR2300076170.

Analysis of anaesthesia incidents during caesarean section reported to webAIRS between 2009 and 2022

Anaesthesia for caesarean section occurs commonly and places specific demands on anaesthetists. We analysed 469 narratives concerning anaesthesia for caesarean section, entered by Australian and New Zealand anaesthetists into the webAIRS incident reporting system between 2009 and 2022. As expected, compared with the remaining 8978 database entries, the 469 incidents were more likely to be emergency cases (relative risk (RR) 1.95), more likely to occur between 18:00 and 22:00 hours (RR 1.81) and between 22:00 and 07:59 hours (RR 4.40) and more likely to be undertaken using neuraxial anaesthesia (RR 9.18). Most incidents involved more than one event. The most commonly reported incidents included intraoperative neuraxial anaesthesia complications (180, 38%), medication errors or issues (136, 29%), equipment issues (49, 10%), obstetric haemorrhage (38, 8%), maternal cardiac arrests (28, 6%), endotracheal tube issues (28, 6%) and neonatal resuscitation (24, 5%). Inadequate neuraxial block, reported in 95 incidents, was the most common intraoperative neuraxial complication. Allergic reactions, reported in 30 incidents, were the most common medication issue, followed by 17 associated with oxytocin and 16 syringe swaps. Thirty-eight reports included significant maternal haemorrhage, with eight of those incidents including maternal cardiac arrest. There was one maternal death and eight incidents with neonatal deaths reported, affecting nine neonates. Problems with intraoperative neuraxial anaesthesia were the most commonly reported events. Implementation of specific strategies are encouraged to enhance preparation for conversion to general anaesthesia and to mitigate medication errors, particularly those relating to oxytocic use and neuraxial anaesthesia medications.

Crash Caesarean Delivery: How to Optimise Decision-to-Delivery Interval by Initiating a Novel Code? A Clinical Audit

Background

Many resource-constrained centres fail to meet the international standard of 30 min of decision-to-delivery interval (DDI) of Category-1 crash caesarean deliveries. However, specific scenarios like acute foetal bradycardia and antepartum haemorrhage necessitate even faster interventions.

Methods

A multidisciplinary team developed a "CODE-10 Crash Caesarean" rapid response protocol to limit DDI to 15 min. A multidisciplinary committee analysed a retrospective clinical audit of maternal-foetal outcomes over 15 months (August 2020-November 2021), and expert recommendations were sought.

Results

The median DDI of twenty-five patients who underwent a "CODE-10 Crash Caesarean delivery" was 13 ± 6 min, with 92% (23/25) of DDIs falling below 15 min. Seven neonates required intensive care for more than 24 h with no maternal or neonatal mortality. DDIs during office and non-office hours were not significantly different (12.5 ± 6 min vs 13 ± 5 min, p = 0.911). Transport delays caused the two instances of DDI > 15 min.

Conclusion

The novel "CODE-10 Crash Caesarean" protocol may be feasible for adoption in a similar tertiary-care setting with appropriate planning and training.

Simulation-based training in obstetric anesthesia: an update

In this update we explore the current applications of simulation in obstetric anesthesia, describe what is known regarding its impacts on care and consider the different settings in which simulation programs are required. We will introduce practical strategies, such as cognitive aids and communication tools, that can be applied in the obstetric setting and share ways in which a program might apply these tools. Finally, we provide a list of common obstetric emergencies essential for a program's curriculum and common teamwork pitfalls to address within a comprehensive obstetric anesthesia simulation program.

Incidence of conversion to general anaesthesia and need for intravenous supplementation in parturients undergoing caesarean section under spinal anaesthesia: A retrospective observational study

BACKGROUND

Conversion from spinal anaesthesia to general anaesthesia (GA) was shown to be associated with more complications. It has been postulated that spinal injection of a low dose of local anaesthetic is a risk factor. We aimed to discover the rate of conversion from spinal anaesthesia to GA in women who received at least 10 mg heavy bupivacaine and opioids and assess its risk factors.

METHODS

All women that underwent spinal anaesthesia for caesarean section from 1 January 2017 to 31 December 2020 were included in this analysis. Spinal anaesthesia was performed according to department protocol using heavy bupivacaine 0.5% 10-13 mg, fentanyl 20 μg, and morphine 0.1 mg. We examined rate of conversion from spinal anaesthesia to GA and rate of need for analgesia/sedation.

RESULTS

There were 1.7% of women that required conversion to GA. Bupivacaine dose (OR 0.54 [95% CI 0.38 to 0.75], p < 0.001), surgery time (OR 1.03 [95% CI 1.02 to 1.04], p < 0.001), emergency caesarean section (OR 1.06 [95% CI 1.16 to 3.76], p = 0.015), and postpartum haemorrhage (OR 5.96 [95% CI 1.09 to 25.18], p = 0.025) were independent predictors of need for conversion to GA. Of the women who had CS under spinal anaesthesia, 4.1% of parturients required intraoperative analgesics/sedatives and 9.1% required anxiolysis.

CONCLUSIONS

A small proportion of women required conversion to GA. This conversion occurred especially with emergency caesarean section and when low spinal bupivacaine doses were used.

Accuracy of Fetal Biacromial Diameter and Derived Ultrasonographic Parameters to Predict Shoulder Dystocia: A Prospective Observational Study

Background and Objectives: Shoulder dystocia (ShD) is one of most dangerous obstetric complication. The objective of this study was to determine if the ultrasonographic fetal biacromial diameter (BA) and derived parameters could predict ShD in uncomplicated term pregnancies. Materials and Methods: We conducted a prospective observational study in a tertiary care university hospital from March 2021 to February 2022. We included all full-term pregnancies accepted for delivery that received an accurate ultrasonography (USG) scan before delivery. USG biometry and estimated fetal weight (EFW) were collected. Therefore, we evaluated the diameter of the mid-arm, the transverse thoracic diameter (TTD) and the biacromial diameter (BA). BA was estimated using Youssef’s formula: TTD + 2 mid-arm diameters. The primary outcome was the evaluation of BA and its related parameters (BA/biparietal diameter (BPD), BA/head circumference (HC) and BA–BPD in fetuses with ShD versus fetuses without ShD. Diagnostic accuracy for ShD of BA, BA/BPD, BA/HC and BA–BPD was evaluated using receiver operator curve (ROC) analysis. Results: 90 women were included in the analysis, four of these had ShD and required extra maneuvers after head delivery. BA was increased in fetuses with ShD (150.4 cm; 95% CI 133.2 cm to 167.6 cm) compared to no-ShD (133.5 cm; 95% CI 130.1 cm to 137.0 cm; p = 0.04). Significant differences were also found between ShD and no-ShD groups for BA/BPD (1.66 (95% CI 1.46 to 1.86) vs. 1.44 (95% CI 1.41 to 1.48); p = 0.04), BA/HC (0.45 (95% CI 0.40 to 0.49) vs. 0.39 (95% CI 0.38 to 0.40); p = 0.01), BA–BPD (60.0 mm (95% CI 42.4 to 77.6 cm) vs. 41.4 (95% CI 38.2 to 44.6); p = 0.03), respectively. ROC analysis showed an overall good accuracy for ShD, with an AUC of 0.821 (p = 0.001) for BA alone and 0.881 (p = 0.001), 0.857 (p = 0.016) and 0.867 (p = 0.013) for BA/BPD, BA–BPD and BA/HC, respectively. Conclusions: BA alone, as well as BA/BPD, BA/HC and BA–BPD might be useful predictors of ShD in uncomplicated term pregnancies. However, such evidence needs extensive confirmation by means of additional studies with large sample sizes, especially in case of pregnancies at high risk for ShD (i.e., gestational diabetes).

Unilateral radiculopathy away from the puncture site due to adhesive arachnoiditis after spinal anesthesia for an emergent cesarean delivery: a case report

Background

Adhesive arachnoiditis has been described as a deteriorating neurological complication after neuraxial blockade; however, few pieces of literatures have reported minor cases that resemble peripheral neuropathy.

Case presentation

A 29-year-old nulliparous woman underwent an emergent cesarean delivery under spinal anesthesia at the second and third lumbar interspace (L2/3) without any specific concerns. Subsequently, she developed left L5 and sacral first (S1) radiculopathy that persisted for 2 months. Although the neurological findings more likely indicated peripheral neuropathy, magnetic resonance imaging revealed localized adhesive arachnoiditis at the left L5/S1 level. Her symptoms gradually improved and entirely disappeared within 2 months without any particular treatment.

Conclusion

The neurological symptoms that show a clear tendency to improve spontaneously do not always undergo a detailed workup. Therefore, such minor adhesive arachnoiditis might have occurred more than expected. Imaging such cases might cumulatively further the understanding of its etiology.

The current practice of aspiration prophylaxis in obstetric anesthesia: a survey among non-physician anesthetic providers working in hospitals in Ethiopia

BACKGROUND

Pulmonary aspiration is one of the most important complications of obstetric anesthesia. Prevention of pulmonary aspiration is commonly performed by the application of different anesthetic maneuvers and administration of drugs. This study aimed to assess the non-physician anesthetic providers current practice of aspiration prophylaxis during anesthesia for cesarean section in Ethiopia.

METHODS

This survey study was conducted from October 01 to November 05, 2020, on a total of 490 anesthetic providers working in hospitals in Ethiopia. A structured checklist was used to collect data from non-physician anesthetic providers.

RESULTS

Four hundred and ninety (490) anesthetic providers participated in our study. The majority of the respondents (84%) were working in the public sector. Most of the cesarean delivery was done under regional anesthesia and more than half of anesthetic providers in Ethiopia administered aspiration prophylaxis routinely. Metoclopramide was the most frequently given as a prophylaxis for pulmonary aspiration.

CONCLUSIONS

More than half of the anesthetic providers administered aspiration prophylaxis routinely. Metoclopramide was the commonest administered aspiration prophylaxis for parturients who underwent cesarean delivery to prevent aspiration.

Intraoperative pain during caesarean delivery: Incidence, risk factors and physician perception

BACKGROUND

Intraoperative pain is a possible complication of neuraxial anaesthesia for caesarean delivery. There is little information available about its incidence, risk factors and physician perception.

METHODS

Parturients undergoing spinal anaesthesia for elective caesarean delivery were enrolled. Before surgery, parturients were asked about preoperative anxiety on a verbal numerical scale (VNS), anticipated analgesic requirement, postoperative pain levels, Spielberger STATE-TRAIT inventory index, Pain Catastrophizing Scale. After surgery, parturients were asked to answer questions (intraoperative VNS pain). The anaesthesiologist and obstetrician were asked to fill out a questionnaire asking about perceived intraoperative pain. Influence of preoperative anxiety on intraoperative pain (yes/no) was assessed using logistic regression. Mc Fadden's R² was calculated. The agreement in physician perception of intraoperative pain with reported pain by the parturient was examined by calculating Cohen's kappa and 95% Confidence Intervals (CI).

RESULTS

We included 193 parturients in our analysis. Incidence of intraoperative pain was 11.9%. Median intraoperative VNS pain of parturients with pain was 4.0 (1st quartile 4.0; 3rd quartile 9.0). Preoperative anxiety was not a good predictor of intraoperative pain (p-value of β-coefficient = 0.43, Mc Fadden's R²  = 0.01). Including further preoperative variables did not result in a good prediction model. Cohen's kappa between reported pain by parturient and by the obstetrician was 0.21 (95% CI: 0.01, 0.41) and by the anaesthesiologist was 0.3 (95% CI: 0.12, 0.48).

CONCLUSIONS

We found a substantial incidence (11.9%) of intraoperative pain during caesarean delivery. Preoperative anxiety did not predict intraoperative pain. Physicians did not accurately identify parturients' intraoperative pain.

SIGNIFICANCE

Intraoperative pain occurred in 11.9% and severe intraoperative pain occurred in 1.11% of parturients undergoing elective caesarean delivery under spinal anaesthesia. We did not find any preoperative variables that could reliably predict intraoperative pain. Obstetricians and anaesthesiologists underestimated the incidence of intraoperative pain in our cohort and thus, more attention must be put to parturients' pain.

Incidence of accidental awareness during general anaesthesia in obstetrics: a multicentre, prospective cohort study

General anaesthesia for obstetric surgery has distinct characteristics that may contribute towards a higher risk of accidental awareness during general anaesthesia. The primary aim of this study was to investigate the incidence, experience and psychological implications of unintended conscious awareness during general anaesthesia in obstetric patients. From May 2017 to August 2018, 3115 consenting patients receiving general anaesthesia for obstetric surgery in 72 hospitals in England were recruited to the study. Patients received three repetitions of standardised questioning over 30 days, with responses indicating memories during general anaesthesia that were verified using interviews and record interrogation. A total of 12 patients had certain/probable or possible awareness, an incidence of 1 in 256 (95%CI 149-500) for all obstetric surgery. The incidence was 1 in 212 (95%CI 122-417) for caesarean section surgery. Distressing experiences were reported by seven (58.3%) patients, paralysis by five (41.7%) and paralysis with pain by two (16.7%). Accidental awareness occurred during induction and emergence in nine (75%) of the patients who reported awareness. Factors associated with accidental awareness during general anaesthesia were: high BMI (25-30 kg.m^-2 ); low BMI (<18.5 kg.m^-2 ); out-of-hours surgery; and use of ketamine or thiopental for induction. Standardised psychological impact scores at 30 days were significantly higher in awareness patients (median (IQR [range]) 15 (2.7-52.0 [2-56]) than in patients without awareness 3 (1-9 [0-64]), p = 0.010. Four patients had a provisional diagnosis of post-traumatic stress disorder. We conclude that direct postoperative questioning reveals high rates of accidental awareness during general anaesthesia for obstetric surgery, which has implications for anaesthetic practice, consent and follow-up.

Exploring the challenges of task-centred training in obstetric anaesthesia in the operating theatre environment

BACKGROUND

Task-centred learning forms the basis of procedural training in obstetric anaesthesia. We observed that our residents were not building their competence from experiential practice in the operating theatre. We used a broad-based framework to explore the challenges encountered by the residents and clinical supervisors in the learning and teaching of obstetric anaesthesia.

METHODS

The study was conducted at the KK Women's and Children's Hospital, Singapore, from 1 December 2016 to 30 June 2017. A semi-structured interview format was used in the focus group and individual interviews. Information collection continued until data saturation was reached. The interviews were analysed and the challenges were identified. Fourteen residents and five clinical supervisors participated in the focus group and individual interviews respectively.

FINDINGS

The operating theatre constituted a stressful learning and teaching environment for the participants. Five categories of challenges were identified: (1) clinical conditions, (2) concerns about maternal risk and outcomes, (3) reluctance of the residents to vocalise their learning needs, (4) poor feedback, and (5) lack of opportunities for inter-professional practice. These collective challenges reduced the quality of task-centred learning and the effectiveness of supervisor teaching. We described some strategies to overcome these challenges (dedicated trainee lists, obstetric anaesthesia reflective diary, active mentoring system and in-situ simulation).

CONCLUSIONS

Our study described the challenges of obstetric anaesthesia training in the operating theatre environment in an Asian healthcare setting. Research is needed on the influence of supervisors' concern about maternal risks and their teaching behaviours.

The analgesic effects of intrathecal morphine in comparison with ultrasound-guided transversus abdominis plane block after caesarean section: a randomised controlled trial at a Ugandan regional referral hospital

Both transversus abdominis plane block and intrathecal morphine may produce prolonged postoperative analgesia, but the respective clinical outcomes of these anaesthetic techniques in resource-limited settings are not well described. We randomly assigned patients undergoing caesarean section to receive a hyperbaric bupivacaine (10 mg) spinal anaesthetic followed by an ultrasound-guided transversus abdominis plane block, or a hyperbaric bupivacaine (10 mg) spinal anaesthetic with 100 mcg intrathecal morphine, followed by a postoperative sham block. Supplemental postoperative analgesia included self-administered oral diclofenac 50 mg and paracetamol 1 g every 8 h. Numerical pain rating scores, the need for rescue medication, side-effects and patient satisfaction were recorded at 8, 16 and 24 h. We enrolled a total of 130 patients, with 65 women in each group. The mean numerical rating score for intrathecal morphine vs. transversus abdominis plane blocks at 8 h were: at rest, 2.5 vs. 3.1 (p = 0.04); with coughing, 4.3 vs. 4.8 (p = 0.07); and with movement, 3.6 vs. 4.2 (p = 0.06). At 16 h, respective scores were: 2.9 vs. 3.1 (p = 0.40) at rest; 4.0 vs. 4.3 (p = 0.19) with coughing; and 4.8 vs. 5.0 (p = 0.33) with movement. At 24 h, the respective scores were: 2.9 vs. 2.3 (p = 0.01); 4.6 vs. 4.2 (p = 0.04) with coughing; and 3.9 vs. 3.4 (p = 0.02) with movement. The need for rescue medication and the incidence of pruritis, sedation and nausea and vomiting were similar in both groups. Patient satisfaction with pain control was similar in both groups, with the majority of patients reporting satisfaction as good or excellent. Intrathecal morphine and transversus abdominis plane block provided clinically similar outcomes for pain relief after caesarean section.

Intracranial subdural hematoma after epidural anesthesia: a case report and review of the literature

Background

Intracranial subdural hematoma occurring as a result of a procedure that causes a puncture of the spinal dura mater is extremely rare, with less than 100 cases reported. Often, this condition is initially misdiagnosed and treated as a post dural puncture headache.

Case presentation

A woman presented to our emergency department complaining of a headache 4 days after receiving epidural anesthesia during uncomplicated childbirth. The headache’s characteristics were consistent with a post dural puncture headache, and the patient was initially treated as such. Computed tomography later revealed the presence of bilateral intracranial subdural hematomas. In light of the patient’s clinical status, treatment involved cautious observation only. Repeat imaging revealed spontaneous resolution of the hematomas, and the patient had a benign clinical course.

Conclusions

Headaches are common in the postpartum period, often after receiving epidural or spinal anesthesia. While exceptionally rare, intracranial subdural hematoma may occur as a complication of any procedure that results in spinal dural puncture. The possibility of this potentially life-threatening complication must be kept in mind when evaluating these patients.