Factors affecting fetal bradycardia following combined spinal epidural for labor analgesia: a matched case-control study.

PURPOSE: The combined spinal epidural (CSE) technique for labor analgesia has become increasingly popular owing to its rapid onset of analgesia. However, incidences of fetal bradycardia following CSE have been reported. This study aimed to identify predictors of fetal bradycardia post CSE, such as a decrease in pain scores, the block height, Prostin (dinoprostone; Pfizer) use, and dosage of oxytocin. METHODS: From May 2008 to October 2008, 29 patients were identified to have had an episode of fetal bradycardia. Each case was then matched to three controls, according to age and American Society of Anesthesiology status, selected from 2345 parturients who received a CSE during this period. RESULTS: A unit improvement in the pain score was associated with an increase in the odds of fetal bradycardia by 1.28 (95 % confidence interval [CI]: 1.02-1.60). In a second logistic regression model including sensory level higher than T9, the effect size remained consistent with an odds ratio of 1.22 (95 % CI: 0.97-1.53), supporting the theory that a higher level of sympathetic block (with a higher sensory block taken as a surrogate marker) results in an increased risk of fetal bradycardia. The dosage of oxytocin and the quantity of Prostin used were not found to be risk factors. CONCLUSION: The difference between pre- and post-CSE pain scores, and a higher sensory block height, which are surrogates for a greater degree of sympatholysis, were found to be risk factors for fetal bradycardia post CSE.

A randomized comparison of low doses of hyperbaric bupivacaine in combined spinal-epidural anesthesia for cesarean delivery.

BACKGROUND: The aim of our study was to investigate the block characteristics of intrathecal hyperbaric bupivacaine 7, 8, or 9 mg administered during combined spinal-epidural anesthesia for cesarean delivery and to elucidate the dose that produces adequate sensory blockade for surgery while minimizing the incidence of hypotension, high neuroblockade, and the need for intraoperative epidural supplementation. METHODS: Sixty women presenting for elective cesarean delivery were randomly assigned to one of the 3 groups. Group 7 received intrathecal hyperbaric bupivacaine 7 mg, Group 8 received 8 mg, and Group 9 received 9 mg. Women in all 3 groups received intrathecal morphine 100 microg and IV hydroxyethyl starch 15 mL/kg at the time of initiation of combined spinal-epidural anesthesia. Surgery began when a sensory level of T4 was achieved. Patients were monitored for block characteristics and side effects by a blinded observer. Our primary outcome was the maximum cephalad sensory block height. RESULTS: There was a difference in the maximum extent of cephalad sensory block among groups (Group 7: median T2 [interquartile range T2-T3]; Group 8: median T2 [T1-T2]; Group 9: median T1 [C8-T2]; P = 0.02). However, the time taken to reach T4 was similar in all 3 groups. The incidence of hypotension requiring vasopressors was different among groups (30% in Group 7, 55% in Group 8, and 70% in Group 9; P = 0.04). No patient had inadequate anesthesia. Neonatal outcomes were similar in all 3 groups. CONCLUSION: The lowest dose of hyperbaric bupivacaine (7 mg) provided equally rapid onset and effective anesthesia for cesarean delivery while reducing the incidence of hypotension compared with 8 and 9 mg. However, because of its shorter duration of anesthesia, it may be feasible only when the block can be reinforced using a functional epidural catheter.

Maintaining labour epidural analgesia: what is the best option?

PURPOSE OF REVIEW: The intensity of labour pain is influenced by a multitude of factors. In this article, we discuss recent advances in the administration of labour epidural analgesia which have been targeted at creating a more satisfactory birthing experience for the parturient while safeguarding maternal and fetal well being. RECENT FINDINGS: Induction of analgesia by the combined spinal epidural technique provides rapid onset of profound analgesia with minimal motor blockade, although the impact of the technique on overall maternal satisfaction with analgesia is equivocal. Patient-controlled epidural analgesia has gained acceptance among clinicians and parturients alike, and research has been focused on elucidating the optimal patient-controlled epidural analgesia programme settings. Results from laboratory and clinical studies suggest that intermittent epidural boluses may produce a more uniform block than a continuous basal infusion. Attempts have been made to incorporate background automated intermittent boluses into a patient-controlled epidural analgesia programme, with encouraging results. Computer-integrated patient-controlled epidural analgesia is a novel system that records the history of the patient's analgesic requirement over the past hour and increases its basal infusion rate proportionally to the number of demand-boluses made. The computer-integrated patient-controlled epidural analgesia programme appears to reduce the incidence of breakthrough pain without increasing drug consumption or side effects. SUMMARY: Recent advances in medical technology have equipped us with many novel drug delivery modalities, which will enable us to customize a suitable analgesic regimen for each parturient.