Conversion of regional to general anaesthesia at caesarean section: increasing the use of regional anaesthesia through continuous prospective audit

Clinical hypnosis: implications in anaesthesia and perioperative care

A randomised trial published in the British Journal of Anaesthesia describes hypnosis compared with general anaesthesia in 60 children undergoing superficial surgery. We describe a definition of clinical hypnosis; the goals and conduct of hypnotic communication; and its potential as both an adjunct and, in suitable cases, alternative to traditional pharmacological anaesthesia.

Prolonged duration of epidural labour analgesia decreases the success rate of epidural anaesthesia for caesarean section

OBJECTIVE

To summarise the process of conversion of epidural labour analgesia to anaesthesia for caesarean delivery and explore the relationship between duration of labour analgesia and conversion.

METHODS

Parturients who underwent conversion from epidural labour analgesia to anaesthesia for caesarean delivery between May 2019 and April 2020 at the Chengdu Women's and Children's Central Hospital, Sichuan Maternal and Child Health Hospital, and Jinjiang District Maternal and Child Health Hospital were selected. If the position of the epidural catheter was correct and the effect was good, patients were converted to epidural surgical anaesthesia. If epidural labour analgesia was ineffective, spinal anaesthesia (SA) was administered immediately. For category-1 emergency caesarean sections, general anaesthesia (GA) was administered.

RESULTS

A total of 1084 parturients underwent conversion. Of these, 19 (1.9%) received GA due to the initiation of category-1 emergency caesarean section. 704 (64.9%) were converted to epidural surgical anaesthesia, 2 (0.2%) had failed conversions and were administered GA before delivery, and 357 (32.9%) were converted to SA. Logistic regression analysis showed that prolonged duration of epidural labour analgesia ([Crude odds ratio (OR)=1.065; 95% confidence interval (CI), 1.037-1.094; p < .01]; [Adjusted OR = 1.060; 95% CI, 1.031-1.091; p < .01]) was an independent risk factor for conversion failure. A receiver operating characteristic curve constructed using duration of epidural labour analgesia showed that parturients with a duration of epidural labour analgesia ≥8 h, more frequently required a change of anaesthesia technique during conversion, and the relative risk of conversion failure was 1.54 (95% CI, 1.23-1.93; p < .01).

CONCLUSION

Prolonged duration of epidural labour analgesia increases the possibility of having an invalid epidural catheter, resulting in an increased risk of conversion failure from epidural labour analgesia to epidural surgical anaesthesia. Further, this risk is higher when the time exceeds 8 h. KEY MESSAGESProlonged duration of epidural labour analgesia > 8 h is associated with conversion failure.If it is impossible to judge whether the conversion is successful immediately, spinal anaesthesia should be administered to minimise complications.

Risk factors for labor epidural conversion failure requiring general anesthesia for cesarean delivery

Background and Aims:

To evaluate the rate and risk factors of labor epidural conversion failure requiring general anesthesia for Caesarean delivery (CD).

Material and Methods:

Pregnant patients requiring conversion from labor to CD with a pre-existing labor epidural at our institution from 2009 to 2014 were identified. Through a retrospective review, we compared successful epidural conversion with those who required general anesthesia for CD. Patient characteristics were analyzed to identify risk factors for failed epidural conversion for CD.

Results:

A total of 673 patients were included in the study. The rate of epidural conversion failure was 21%. Main risk factors for epidural conversion failure requiring general anesthesia included: younger maternal age (95% CI 0.94, P = 0.0002) and supplementation of intravenous fentanyl (95% CI 0.19, P < 0.0001) or midazolam (95% CI 0.26, P = 0.0008) during CD. A higher risk of conversion failure was also associated with a more urgent CD (CD category 1, 2, and 3 vs category 4).

Conclusion:

Consistent with previous reports, young age and the urgency of CD increases the likelihood of epidural conversion failure. While conversion failure is likely multifactorial and complex, many of these factors are suggestive of inadequate and poorly functioning labor epidurals prior to CD. Prospective studies to further evaluate these factors are necessary, and the best prevention of epidural conversion failure is diligent diagnosis and evaluation of ineffective labor epidural analgesia prior to impending CD.

Analysis of urgent/emergent conversions from monitored anesthesia care to general anesthesia with airway instrumentation

Background

Monitored Anesthesia Care (MAC) is an anesthetic service involving the titration of sedatives/analgesics to achieve varying levels of sedation while avoiding general anesthesia (GA) and airway instrumentation. The goal of our study was to determine the overall incidence of conversion from MAC to general anesthesia with airway instrumentation and elucidate reasons and risk factors for conversion.

Methods

In this retrospective observational study, all non-obstetric adult patients who received MAC from July 2002 to July 2015 at Mount Sinai Hospital were electronically screened for inclusion via a clinical database. Patient, procedure, anesthetic, and practitioner data were all collected and analyzed to generate descriptive analyses. Subsequent univariate and multivariate analyses were used to identify specific risk factors associated with conversion to GA.

Results

Overall, 0.50% (1097/219,061) of MAC cases were converted to GA. Approximately half of conversions were due to the patient’s “intolerance” of MAC (with or without failed regional anesthesia), while the other half were due to physiologic derangements. Body mass index, male sex, American Society of Anesthesiologists Physical Status Classification, anesthesia team composition, and surgical specialty were all associated with risk of conversion to GA.

Conclusions

This is one of the first and largest retrospective studies aimed at identifying reasons and risk factors associated with the conversion of MAC to GA. These findings may be used to help better anticipate or prevent these events.

Maternal and fetal outcomes following unplanned conversion to general anesthetic at elective cesarean section

OBJECTIVE

To investigate risk factors predicting unplanned conversion to general anesthesia during elective cesarean section, and to examine maternal and fetal outcomes associated with unplanned conversion compared with other modes of anesthesia.

STUDY DESIGN

A retrospective cohort at a UK center (2008 to 2013). Women (4337) underwent elective cesarean section. Delivery outcomes were compared according to anesthesia type using logistic regression.

RESULT

Women (1.6%) underwent unplanned conversion to general anesthetic. Unplanned conversion was associated with higher parity (odds ratio (OR) 3.82, confidence interval (CI; (1.58 to 9.62)) and maternal age ⩾40 (OR 4.40, CI (1.08 to 29.88)). Compared with spinal anesthetic, unplanned conversion was associated with increased likelihood of maternal hemorrhage ⩾1.5 l (OR 5.74, CI (1.90 to 14.01)) and delayed neonatal respiration (OR 4.76, CI (1.76 to 11.05)). Adverse outcomes were not significantly more likely compared with planned general anesthetic.

CONCLUSION

Higher parity and maternal age are risk factors for unplanned conversion to general anesthetic. There is no increase in the likelihood of adverse outcomes with unplanned versus planned general anesthetic.

Mode of anaesthesia for preterm Caesarean delivery: secondary analysis from the Maternal-Fetal Medicine Units Network Caesarean Registry

BACKGROUND

Preterm delivery is often performed by Caesarean section. We investigated modes of anaesthesia and risk factors for general anaesthesia among women undergoing preterm Caesarean delivery.

METHODS

Women undergoing Caesarean delivery between 24(+0) and 36(+6) weeks' gestation were identified from a multicentre US registry. The mode of anaesthesia was classified as neuraxial anaesthesia (spinal, epidural, or combined spinal and epidural) or general anaesthesia. Logistic regression was used to identify patient characteristic, obstetric, and peripartum risk factors associated with general anaesthesia.

RESULTS

Within the study cohort, 11 539 women had preterm Caesarean delivery; 9510 (82.4%) underwent neuraxial anaesthesia and 2029 (17.6%) general anaesthesia. In our multivariate model, African-American race [adjusted odds ratio (aOR)=1.9; 95% confidence interval (CI)=1.7-2.2], Hispanic ethnicity (aOR=1.5; 95% CI=1.2-1.8), other race (aOR=1.4; 95% CI=1.1-1.9), and haemolysis, elevated liver enzymes and low platelets (HELLP) syndrome or eclampsia (aOR=2.8; 95% CI=2.2-3.5) were independently associated with receiving general anaesthesia for preterm Caesarean delivery. Women with an emergency Caesarean delivery indication had the highest odds for general anaesthesia (aOR=3.5; 95% CI=3.1-3.9). For every 1 week decrease in gestational age at delivery, the adjusted odds of general anaesthesia increased by 13%.

CONCLUSIONS

In our study cohort, nearly one in five women received general anaesthesia for preterm Caesarean delivery. Although potential confounding by unmeasured factors cannot be excluded, our findings suggest that early gestational age at delivery, emergent Caesarean delivery indications, hypertensive disease, and non-Caucasian race or ethnicity are associated with general anaesthesia for preterm Caesarean delivery.

Perioperative anesthetic documentation: Adherence to current Australian guidelines

Purpose:

The lack of adequate perioperative documentation has legal implications and can potentially affect the quality and safety of patient care. Despite the presence of guidelines, the adequacy of perioperative documentation in Australasia has not been adequately assessed. The aim of this study is to assess the adequacy of anesthetic documentation on the pre and intraoperative encounters and to test the hypotheses that documentation is incomplete in the settings of emergency vs. elective procedures, regional vs. general anesthesia, and manual vs. electronic documentation.

Materials and Methods:

The study was an observational retrospective study in the setting of a 250-bed teaching hospital in metropolitan Adelaide, Australia. The perioperative records of 850 patients were analyzed. A scoring system was designed, based on a policy statement from the Australian and New Zealand College of Anesthetists and a survey of the hospital anesthetists. Scored and categorical data was analyzed using Chi-square test. Numerical data was analyzed using student t-test. The null hypothesis was accepted or rejected at 0.05 significance.

Results:

There were significant deficiencies in the adequacy of preanesthetic and intraoperative records. This has been shown to be true in all cases. Documentation was found to be poorer in the emergency setting when compared to elective cases (median scores 15 vs. 21 P = 0.03) as well as documentation of airway assessment for cases done solely under regional anesthesia (42 vs. 85%, P = 0.05). There were no significant differences in the adequacy of electronic vs. manual records (P = 0.92).

Conclusion:

There are significant deficiencies in the adequacy of perioperative records. This has been shown to be true in all cases, but is especially so in emergency cases and for patients having only regional anesthesia.

Near-infrared tracking system for epidural catheter placement: a feasibility study

BACKGROUND

Epidural catheters are routinely used in regional and obstetric anesthesia. The flexible catheter is advanced without imaging control into the epidural space, and coiling or kinking of the catheter may occur, compromising the effectiveness of epidural anesthesia. Potentially near-infrared (NER) light detection may help, tracking advancement of the catheter in the epidural space.

METHODS

Nonembalmed human cadavers donated to the University of Washington Willed Body program were placed prone. Catheters containing NER-emitting wire were introduced into the lumbar and thoracic epidural space. The progress of the emitting wire was tracked using the LumenVu NER guidance system, and the final location of the catheter was confirmed with fluoroscopy.

RESULTS

Total 12 attempts were made to place the catheter. In 7 cases (4 lumbar and 3 thoracic), good progression of the catheter in the epidural space was achieved with excellent visibility at low NER power levels. Maximum light intensity was registered when the catheter tip was found in the midline dorsal interlaminar position, as confirmed by fluoroscopy. The light intensity decreased while the catheter tip was traversing under the lamina. Poor progression of the catheter with negligible visibility of the tip at the highest NER level occurred in obese specimen (n = 2) or when the tip was in extraforaminal (n = 1), paramedian or paravertebral positions (n = 2).

CONCLUSIONS

Many variables such as obesity, paravertebral and extraforaminal catheter locations, and intervening bony structures can impede the application of NER technology for epidural catheter placements. Further optimization of the technology for clinical use is necessary.