An 18-year-old woman, gravida 1, para 0, with a body mass index of 51 kg/m2, presented for induction of labor at 40 weeks’ gestation due to oligohydramnios. An epidural catheter was placed at the L3-L4 intervertebral space when the patient reached 3 cm cervical dilation. Successful labor analgesia was obtained with patient-controlled epidural analgesia, delivering bupivacaine 0.125% with fentanyl 2 mcg/mL at a continuous infusion rate of 10 mL per hour and boluses of 3 mL at 15-minute lockout intervals.
After consulting with the patient, the epidural anesthetic was converted to general anesthesia. At the conclusion of surgery, before extubation, bilateral transverse abdominis plane blocks were performed. Twenty-four hours following delivery, the patient’s pain score was 2 out of 10, and she expressed satisfaction with her anesthetic care.
The majority of cesarean deliveries are performed under neuraxial anesthesia.1 General anesthesia for cesarean delivery is best avoided due to an increased risk for maternal adverse effects. In the United States, the rate of general anesthesia usage for delivery, as reported by the National Anesthesiology Clinical Outcomes data set, is 5.8%.2 General anesthesia is indicated in certain situations including, but not limited to, cases of obstetric emergencies, contraindications to neuraxial anesthesia and failed neuraxial anesthesia. Spinal anesthesia rarely fails to provide adequate operative conditions for cesarean delivery. However, the reported incidence of failure to convert an existing labor epidural analgesic to epidural anesthesia for cesarean delivery ranges from 1.7% to 19.8%.3,4 Factors that increase the risk for failure to extend labor epidural analgesia to epidural anesthesia for cesarean delivery include an unsatisfactory labor epidural requiring more than two unscheduled boluses for breakthrough pain, young age, obesity, higher gestational week, greater urgency for cesarean delivery and prolonged labor.4-7
Reluctance to convert an inadequate neuraxial anesthetic to general anesthesia frequently results in maternal pain or discomfort, maternal emotional distress, and increased liability for the anesthesiologist. Szypula et al analyzed 841 anesthetic claims reported by the National Health Service Litigation Authority in England.8 Of 366 claims related to regional anesthesia, 186 (51%) were obstetric cases. Pain during cesarean delivery was the most frequent cause for litigation (57 claims), followed by nerve damage and back pain.
Psychological sequelae in patients experiencing pain during cesarean delivery are very frequent. McCombe and Bogod reviewed cases of litigation for this kind of pain in the United Kingdom over a 21-year period.9 Of 76 such patients, 68 (89%) reported psychological distress following the event. Permanent physiologic damage was reported by six patients (11%).
Unsatisfactory pain relief with an epidural block after incision is one of the biggest challenges in obstetric anesthesia. Management options depend on the sensory block level, severity of pain or discomfort, and stage of the operation.
Assessment of the Sensory Block
The optimal method to assess a sensory neuraxial block is controversial. The extent of the sensory block can be checked by loss of sensation to cold, sharp pinprick and touch. Although checking by sensation to cold is used by most anesthesiologists, loss of sensation to touch has been shown to most reliably predict adequate anesthesia for cesarean delivery.10,11 A survey by Husain et al showed that the majority of anesthesiologists in the United Kingdom use more than one modality to assess the sensory block level before the procedure10 A T4-T5 dermatomal level of sensory block is required to achieve satisfactory pain relief during delivery. Although a T4 dermatomal level is easier to identify using clear anatomic landmarks, one in seven anesthesiologists err in two or more segments when identifying that level.12
Any complaint of pain, pressure or other discomfort during surgery needs to be thoroughly and promptly evaluated. It is crucial to believe the patient and accept that some patients may be uncomfortable despite an apparently successful sensory blockade. The severity of pain and extent of discomfort is very difficult to assess and can be complicated by the patient’s fear and anxiety. Offering reassurance, showing empathy and providing emotional support may bring comfort in some situations.
Stage of the Operation
Severe pain immediately following the incision should most likely prompt converting to general anesthesia while implementing precautions for a potential difficult airway, including optimal patient positioning. If time allows and surgery can be stopped (before uterine incision or after delivery of the infant), a functional epidural catheter can be used to administer supplemental fast-acting local anesthetics (e.g., 2-chloroprocaine) and opioids (fentanyl 50-100 mcg). A mixture of lidocaine with epinephrine and fentanyl injected into the epidural catheter can achieve a sensory block in three minutes.13 Alkalinization of the epidurally injected solution with sodium bicarbonate increases the unionized fraction of drug, resulting in a faster onset time.
Patients presenting with mild pain or discomfort at advanced stages of the surgery can be given small doses of systemic medication or nitrous oxide. Midazolam (1-2 mg) provides amnesia, which can be seen as both an advantage and a disadvantage, because the patient may lose the ability to recall the delivery experience. Ketamine administered in small increments of 10 mg, and small doses of fentanyl (50-100 mcg), can be administered with good results. One must keep in mind the danger of losing consciousness in a patient with an unprotected airway and increased risk for aspiration. Surgical field infiltration with local anesthetics by the surgeon can also be helpful. Intraperitoneal instillation of 2-chloroprocaine (mean dose, 11.8 mg/kg) after delivery has been used successfully to supplement intraoperative analgesia during cesarean delivery.14Persistent pain should prompt stopping surgical manipulation and conversion to general anesthesia.
- Pain during cesarean delivery is a frequent cause of patient dissatisfaction and litigation against obstetric anesthesiologists.
- Conversion of neuraxial anesthesia to general anesthesia may be necessary for patient comfort if other methods of treating intraoperative pain have failed.
- A preoperative, detailed explanation of the expected sensations to the patient may alleviate intraoperative discomfort.
- Early recognition of unsatisfactory labor analgesia allows for replacement of the epidural catheter.
- It is essential to believe a patient’s complaint of intraoperative pain despite an apparently successful sensory blockade.
- Guglielminotti J, Landau R, Li G. Adverse events and factors associated with potentially avoidable use of general anesthesia in cesarean deliveries. Anesthesiology. 2019;130(6):912-922.
- Juang J, Gabriel RA, Dutton RP, et al. Choice of anesthesia for cesarean delivery: an analysis of the National Anesthesia Clinical Outcomes Registry. Anesth Analg. 2017;124(6):1914-1917.
- Paech MJ, Godkin R, Webster S. Complications of obstetric epidural analgesia and anesthesia: a prospective analysis of 10 995 cases. Int J Obstet Anesth. 1998;7(1):5-11.
- Orbach-Zinger S, Friedman L, Avramovich A, et al. Risk factors for failure to extend labor epidural analgesia to epidural anesthesia for cesarean section. Acta Anaesthesiol Scand. 2006;50(7):793-797.
- Portnoy D, Vadhera R. Mechanisms and management of an incomplete epidural block for cesarean section. Anesthesiol Clin North Am. 2003;21(1):39-57.
- Bauer ME, Kountanis JA, Tsen LC, et al. Risk factors for failed conversion of labor epidural analgesia to cesarean delivery anesthesia: a systematic review and meta-analysis of observational trials. Int J Obstet Anesth. 2012;21(4):294-309.
- Lee S, Lew E, Lim Y, et al. Failure of augmentation of labor epidural analgesia for intrapartum cesarean delivery: a retrospective review. Anesth Analg. 2009;108(1):252-254.
- Szypula K, Ashpole KJ, Bogod D, et al. Litigation related to regional anaesthesia: an analysis of claims against the NHS in England 1995-2007. Anaesthesia. 2010;65(5):443-452.
- McCombe K, Bogod DG. Learning from the law. A review of 21 years of litigation for pain during caesarean section. Anaesthesia. 2018;73(2):223-230.
- Husain T, Liu YM, Fernando R, et al. How UK obstetric anaesthetists assess neuraxial anaesthesia for caesarean delivery: national surveys of practice conducted in 2004 and 2010. Int J Obstet Anesth. 2013;22(4):298-302.
- Russell IF. Assessing the block for caesarean section. Int J Obstet Anesth. 2001;10(2):83-85.
- Congreve K, Gardner I, Laxton C, et al. Where is T5? A survey of anaesthetists. Anaesthesia. 2006;61(5):453-455.
- Hillyard SG, Bate TE, Corcoran TB, et al. Extending epidural analgesia for emergency caesarean section: a meta-analysis. Br J Anaesth. 2011;107(5):668-678.
- Werntz M, Burwick R, Togioka B. Intraperitoneal chloroprocaine is a useful adjunct to neuraxial block during cesarean delivery: a case series. Int J Obstet Anesth. 2018;35:33-41.