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

Failed spinal anesthesia for cesarean delivery: prevention, identification and management

PURPOSE OF REVIEW

There is an increasing awareness of the significance of intraoperative pain during cesarean delivery. Failure of spinal anesthesia for cesarean delivery can occur preoperatively or intraoperatively. Testing of the neuraxial block can identify preoperative failure. Recognition of the risk of high neuraxial block in repeat spinal in case of preoperative failure is important.

RECENT FINDING

Knowledge of risk factors for block failure facilitates prevention by selecting the most appropriate neuraxial procedure, adequate intrathecal doses and choice of technique. Intraoperative pain is not uncommon, and neither obstetricians nor anesthesiologists can adequately identify intraoperative pain. Early intraoperative pain should be treated differently from pain towards the end of surgery.

SUMMARY

Block testing is crucial to identify preoperative failure of spinal anesthesia. Repeat neuraxial is possible but care must be taken with dosing. In this situation, switching to a combined spinal epidural or an epidural technique can be useful. Intraoperative pain must be acknowledged and adequately treated, including offering general anesthesia. Preoperative informed consent should include block failure and its management.

Incidence and clinical impact of aspiration during cesarean delivery: A multi-center retrospective study

BACKGROUND

The risk of aspiration during general anesthesia for cesarean delivery has long been thought to be increased due to factors such as increased intra-abdominal pressures and delayed gastric emptying in pregnant patients. However, recent studies have reported normal gastric emptying in pregnant patients, suggesting that the risk of aspiration may not be as high as previously believed.

METHODS

We conducted a retrospective study of 48,609 cesarean deliveries, of which 22,690 (46.7%) were performed under general anesthesia at two large tertiary medical centers in Israel. The study aimed to examine the incidence of potentially severe aspiration during cesarean delivery, both under general and neuraxial anesthesia.

RESULTS

Among the patients included in the study, three were admitted to the intensive care unit due to suspected pulmonary aspiration. Two of these cases occurred during induction of general anesthesia for emergency cesarean delivery associated with difficult intubation and one under deep sedation during spinal anesthesia. The incidence of aspiration during cesarean delivery during general anesthesia in our study was 1 in 11,345 patients, and the incidence of aspiration during neuraxial anesthesia was 1 in 25,929 patients. No deaths due to aspiration were reported during the study period.

CONCLUSIONS

Our findings provide another contemporary analysis of aspiration rates in obstetric patients, highlighting increased risks during the management of difficult airways during general anesthesia and deep sedation associated with neuraxial anesthesia.

General Versus Nongeneral Anesthesia for Carotid Endarterectomy: A Prospective Multicenter Registry-Based Study on 25 000 Patients

BACKGROUND AND OBJECTIVES

Carotid endarterectomy (CEA) is a well-established treatment option for carotid stenosis. The choice between general anesthesia (GA) and nongeneral anesthesia (non-GA) during CEA remains a subject of debate, with concerns regarding perioperative complications, particularly myocardial infarctions. This study aimed to evaluate the outcomes associated with GA vs non-GA CEA using a large, nationwide database.

METHODS

The National Surgical Quality Improvement Project database was queried for patients undergoing CEA between 2013 and 2020. Primary outcome measures including surgical outcomes and 30-day postoperative complications were compared between the 2 anesthesia methods, after 2:1 propensity score matching.

RESULTS

After propensity score matching, a total of 25 356 patients (16 904 in the GA and 8452 in the non-GA group) were included. Non-GA compared with GA CEA was associated with significantly shorter operative times (101.9, 95% CI: 100.5-103.3 vs 115.8 95% CI: 114.4-117.2 minutes, P < .001), reduced length of hospital stays (2.3, 95% CI: 2.15-2.4 vs 2.5, 95% CI: 2.4-2.6 days, P < .001), and lower rates of 30-day postoperative complications, including myocardial infarctions (0.8% vs 1.2%, P = .003), unplanned intubations (0.8% vs 1.1%, P = .016), pneumonia (0.5% vs 1%, P < .001), and urinary tract infections (0.4% vs 0.7%, P = .003). These outcomes were notably more pronounced in the younger (≤70 years) and high morbidity (American Society of Anesthesiologists 3-5) cohorts.

CONCLUSION

In this nationwide registry-based study, non-GA CEA was associated with better short-term outcomes in terms of perioperative complications, compared with GA CEA. The findings suggest that non-GA CEA may be a safer alternative, especially in younger patients and those with more comorbidities.

Pain during cesarean delivery: A patient-related prospective observational study assessing the incidence and risk factors for intraoperative pain and intravenous medication administration

INTRODUCTION

The incidence of pain during cesarean delivery (PDCD) remains unclear. Most studies evaluated PDCD using interventions suggesting inadequate analgesia: neuraxial replacement, unplanned intravenous medication (IVM), or conversion to general anesthesia. Few assess self-reported pain. This study evaluates the incidence of and risk factors for self-reported PDCD and IVM administration.

METHODS

Between May and September 2022, English-speaking women undergoing cesarean delivery under neuraxial anesthesia were approached within the first 48 h. Participants answered a 16-question survey about intraoperative anesthesia care. Clinical characteristics were extracted from electronic medical records. The primary outcome was PDCD. Secondary outcomes were analgesic IVM (opioids alone or in combination with ketamine, midazolam, or dexmedetomidine) and conversion to general anesthesia. Risk factors for PDCD and analgesic IVM were identified using multivariable logistic regression models.

RESULTS

Pain was reported by 46/399 (11.5%; 95% CI: 8.6, 15.1) participants. Analgesic IVM was administered to 16 (34.8%) women with PDCD and 45 (12.6%) without. Conversion to general anesthesia occurred in 3 (6.5%) women with and 4 (1.1%) without PDCD. Risk factors associated with PDCD were substance use disorder and intrapartum epidural extension. Risk factors associated with analgesic IVM were PDCD, intrapartum epidural extension when ≥2 epidural top-ups were given for labor analgesia, and longer surgical duration.

DISCUSSION

In our cohort of scheduled and unplanned cesarean deliveries, the incidence of PDCD was 11.5%. A significant proportion of women (15.1%) received analgesic IVM, of which some but not all reported pain, which requires further evaluation to identify triggers for IVM administration and strategies optimizing shared decision-making.

Correlation of thecal sac cross sectional area to total volume

BACKGROUND

Spinal anesthesia (SA) has been increasingly utilized in lumbar surgery due to its various advantages over general anesthesia (GA), however failure of the first dose requiring intraoperative conversion to GA occurs in as many as 3.6% of SA patients. Some studies have reported that a larger thecal sac volume may dilute the anesthetic and play a role in first dose failure. Unfortunately, easy determination of thecal sac volume has not been reported in the literature. Thus, we sought to determine whether cross-sectional area obtained from MRI accurately predicts the volume of the thecal sac.

METHODS

We conducted a retrospective review of 80 patients who underwent lumbar surgery with spinal anesthesia. T1 and T2-weighted MRI sequences were used to measure thecal sac area at each level between L1-S1. The volume of the thecal sac was calculated using HorosTM. A statistical model was derived relating the area at each level to the thecal sac volume. Of the 80 patients, 20% were reserved and utilized to test the accuracy of the statistical model.

RESULTS

The area of the thecal sac positively correlated with volume at each lumbar level. The area of the thecal sac at the L4-L5 level most accurately represented total thecal sac volume (R2 = 0.588, RMSE = 2.76).

CONCLUSION

Cross-sectional area of the L4-L5 spinal level obtained from MRI sequences may be utilized as a proxy for thecal sac volume.