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.

Comparison between 10 and 12 mg doses of intrathecal hyperbaric (0.5%) bupivacaine on sensory block level after first spinal failure in cesarean section: A double-blind, randomized clinical trial

Background

Reducing adverse effects during cesarean delivery and improving the quality of sensory blocks with appropriate doses of intrathecal hyperbaric bupivacaine can play an important role in the safe management of cesarean delivery. The aim of this study was to compare the doses of 10 and 12 mg of intrathecal hyperbaric bupivacaine 0.5% on sensory block level after first spinal failure in cesarean section (CS).

Methods

In this double-blind, randomized clinical trial, 40 candidates of CS after first spinal failure with class I-II based on American Society of Anesthesiologists (ASA) were randomly assigned into two equal groups (n = 20). Group A and B received the spinal anesthesia with 10 mg and 12 mg of hyperbaric bupivacaine (0.5%), respectively. Maximum levels of sensory block, motor block quality, and vital signs were measured in two groups by 60 min after SPA. Incidence of SPA complications during surgery were also recorded. Data were analyzed by SPSS ver.21 software using repeated measures analysis of variance at 95% confidence interval (CI) level.

Results

Excellent quality of sensory blocks and complete quality of motor blocks were achieved in all participants (100%). However, the mean time to onset of anesthesia (4.47 ± 0.69 vs. 3.38 ± 0.47, P < 0.001) and time to reach T10 level (60.73 ± 11.92 vs. 79.00 ± 19.21, P < 0.001) in the Group A, were significantly shorter than in the patients of Group B. The incidence of hypotension (P = 0.001), nausea/vomiting (P = 0.007) and bradycardia (P = 0.012) as well as administration of ephedrine and atropine were significantly higher in Group B compared to Group A.

Conclusion

Spinal anesthesia can be safely repeated with a 10 mg of hyperbaric bupivacaine 0.5% in a caesarean section after the initial spinal failure.

Clinical trial registration

[https://en.irct.ir/trial/40714], identifier [IRCT20120915010841N20].

Approach to failed spinal anaesthesia for caesarean section

Failure of spinal anaesthesia for caesarean section may have deleterious consequences for the mother as well as the newborn baby. In this article, we discuss the mechanisms of failure of spinal anaesthesia as well as the approach to a failed block. We performed a literature search in Google Scholar, PubMed, and Cochrane databases for original and review articles concerning failed spinal anaesthesia and caesarean section. Strategies for a failed spinal anaesthetic include manoeuvers to salvage the block, repeating the block, epidural anaesthesia or a combined spinal-epidural (CSE) technique, or resorting to general anaesthesia. Factors influencing the choice of these alternative options are discussed. A "failed spinal algorithm" can guide the anaesthesiologist and help reduce morbidity and mortality.

Repeat spinal anesthesia in cesarean section: A comparison between 10 mg and 12 mg doses of intrathecal hyperbaric (0.05%) bupivacaine repeated after failed spinal anesthesia: A prospective, parallel group study

Background:

Spinal anesthesia for cesarean section is not a 100% successful technique. At times, despite straightforward insertion and drug administration, intrathecal anesthesia for cesarean section fails to obtain any sensory or motor block. Very few studies and literature are available regarding repeat administration of spinal anesthesia and its drug dosage, especially after first spinal failure in cesarean section lower segment cesarean section (LSCS) due to fear of the excessive spread of drug. The aim of our study is to compare the outcome between two different doses of 0.5% hyperbaric bupivacaine repeated intrathecally after failed spinal.

Materials and Methods:

After taking informed consent and Ethical Committee approval this prospective, randomized single-blinded study was conducted in 100 parturients of American Society of Anesthesiologists I-II who were posted for elective LSCS and had Bromage score 0 and no sensory block even at L₄ dermatome after 10 min of first spinal anesthesia; were included in the study. Group A (n = 50) patients received 2.4 ml and Group B (n = 50) patients received 2 ml of 0.5% hyperbaric bupivacaine respectively for administering repeat spinal anesthesia. Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), oxygen saturation, respiratory rate and electrocardiogram were monitored both intra- and post-operatively and complications were recorded.

Results:

Incidence of high spinal, bradycardia, hypotension, respiratory complications, and nausea vomiting are significantly higher in Group A compared to Group B (P < 0.05). SBP, DBP, and HR were significantly low in Group A patients compared to Group B in the first 10 min (P < 0.05).

Conclusion:

Spinal anesthesia can be safely repeated in the cesarean section with 10 mg of 0.5% hyperbaric bupivacaine provided after first spinal anesthesia, the level of sensory block is below L₄ and motor power in Bromage scale is 0.