Maternal fever, neonatal sepsis evaluation, and epidural labor analgesia.

BACKGROUND AND OBJECTIVES: Numerous studies have found an association between epidural analgesia for labor and maternal fever (temperature > or =38 degrees C). Maternal fever often results in treatment with maternal or neonatal antibiotics, neonatal sepsis evaluation, and increased costs. METHODS: Medline was used to identify literature regarding the association between epidural labor analgesia and maternal fever/neonatal sepsis. Studies examining thermoregulation during pregnancy and/or epidural analgesia were also reviewed. RESULTS: There appears to be a strong association between epidural labor analgesia and maternal fever. The link between epidural labor analgesia and neonatal sepsis evaluation is less clear. The incidence of confirmed neonatal sepsis does not increase with maternal epidural analgesia. Causes of the association between epidural labor analgesia and maternal fever include selection bias, altered thermoregulation, and increased shivering or decreased sweating with epidural analgesia. CONCLUSIONS: Maternal epidural labor analgesia is associated with maternal fever and possibly increased neonatal sepsis evaluation. There is no proof the relationship is causal.

Intrathecal fentanyl is superior to intravenous ondansetron for the prevention of perioperative nausea during cesarean delivery with spinal anesthesia.

This study compares intrathecal (IT) fentanyl with IV ondansetron for preventing intraoperative nausea and vomiting during cesarean deliveries performed with spinal anesthesia. Thirty healthy parturients presenting for elective cesarean delivery with standardized bupivacaine spinal anesthesia were randomized to receive 20 microg IT fentanyl (Group F) or 4 mg IV ondansetron (Group O) by using double-blinded methodology. At eight specific intervals during the surgery, a blinded observer questioned the patient about nausea (1 = nausea, 0 = no nausea), observed for the presence of retching or vomiting (1 = vomiting or retching, 0 = no vomiting or retching), and recorded a verbal pain score (0-10, 0 = no pain, 10 = worst pain imaginable). Cumulative nausea, vomiting, and pain scores were calculated as the sum of the eight measurements. Intraoperative nausea was decreased in the IT fentanyl group compared with the IV ondansetron group: the median (interquartile range) difference in nausea scores was 1 (1, 2), P = 0.03. The incidence of vomiting and treatment for vomiting was not different (P = 0.7). The IT fentanyl group had a lower cumulative perioperative pain score than the IV ondansetron group; the median difference in the cumulative pain score was 12 (8, 16) (P = 0.0007). The IT fentanyl group required less supplementary intraoperative analgesia. The median difference in the cumulative fentanyl dose was 100 (75, 100) microg fentanyl, (P = 0.0002).

Intrathecal lipophilic opioids as adjuncts to surgical spinal anesthesia.

BACKGROUND AND OBJECTIVES: Lipophilic opioids, especially fentanyl and sufentanil, are increasingly being administered intrathecally as adjuncts to spinal anesthesia. This review analyzes the efficacy of these opioids for subarachnoid anesthesia. METHODS: Medline search of the literature from 1980 to the present and a survey of recent meeting abstracts are reviewed. RESULTS: A significant number of citations regarding intrathecal lipophilic opioids as adjuncts to spinal anesthesia were found: 59 are cited in this review. Most clinical experience has been in obstetric surgery, but lipophilic spinal opioid administration is being used with greater frequency for other surgical procedures as well. The benefits include reduction of minimal alveolar concentration (MAC) when general anesthesia is combined with spinal anesthesia and enhancement of the quality of spinal anesthesia without prolongation of motor block. Intrathecal fentanyl and sufentanil allow clinicians to use smaller doses of spinal local anesthetic, yet still provide excellent anesthesia for surgical procedures. Furthermore, lipophilic opioid/local anesthetic combination permits more rapid motor recovery; short outpatient procedures are therefore more amenable to spinal anesthesia. Finally, the side-effect profiles of intrathecal lipophilic opioids are now well characterized and appear less troublesome than intrathecal morphine. CONCLUSIONS: The anesthesia-enhancing properties and side-effect profile of lipophilic opioids administered intrathecally suggest significant roles for these agents as adjuncts to spinal anesthesia for obstetric and outpatient procedures.

The use of remifentanil infusion to facilitate epidural catheter placement in a parturient: a case report with pharmacokinetic simulations.

We present a case in which remifentanil infusion was used to provide analgesia during epidural catheter placement in a parturient who was experiencing great difficulty staying motionless because of extremely painful uterine contractions. Remifentanil may provide certain advantages in this setting, including improved analgesia during the procedure, briefer residual maternal and fetal (or newborn) drug effects after the procedure, and greater technical ease of catheter placement because of decreased movement induced by pain. Pharmacokinetic simulation of the dose administered suggests that analgesic effect-site concentrations can be rapidly produced, and that these concentrations decline rapidly to clinically insignificant levels after the infusion.

Opioid-induced rigidity after intravenous fentanyl.

BACKGROUND: Large doses of intravenous opioids may cause severe rigidity and prevent spontaneous or controlled ventilation. The mechanism of this effect appears to be neuraxis dopamine antagonism. Rigidity after analgesic doses of fentanyl has not been reported previously. CASE: A pregnant woman receiving haloperidol for multiple psychiatric conditions presented for evaluation of vaginal bleeding. Intravenous fentanyl was administered to facilitate vaginal examination. Severe rigidity of the extremities and truncal region occurred, which prevented spontaneous or assisted ventilation. CONCLUSION: Opioid administration may result in rigidity and respiratory embarrassment. Decreased analgesic requirements in pregnancy and concomitant butyrophenone administration may predispose to opioid-induced rigidity.

Duration of intrathecal labor analgesia: early versus advanced labor.

Early first-stage labor pain is primarily visceral in origin. Increasing pain intensity and transition to somatic nociceptive input characterizes late first- and second-stage labor pain. The effect of this change in nociceptive input on the duration of intrathecal labor analgesia has not been well studied. This prospective cohort observational study compares the duration of intrathecal labor analgesia after intrathecal injections made in early labor (3- to 5-cm cervical dilation) and those made in more advanced labor (7- to 10-cm cervical dilation). Forty-one parturients (18 in early labor and 23 in advanced labor) received intrathecal sufentanil (10 micrograms) and bupivacaine (2.5 mg) as part of a combined spinal-epidural technique. Patients rated their pain using a 0-10 verbal pain scale prior to intrathecal injection and every 20 min thereafter. Duration of analgesia was defined as the lesser of time until the pain score exceeded 5 or until a request for supplemental epidural analgesia was made. The duration of spinal analgesia was significantly less when intrathecal injection was made in advanced labor (120 +/- 26 min) compared with early labor (163 +/- 57 min, P < 0.01). We conclude that cervical dilation and stage of labor significantly impact the effective duration of intrathecal sufentanil/ bupivacaine labor analgesia.

Detection of intravascular epidural catheters using 2-chloroprocaine. Influence of local anesthetic dose and nalbuphine premedication.

BACKGROUND AND OBJECTIVES: Detecting the intravascular placement of epidural catheters is essential to avoid local anesthetic toxicity. Small doses of intravenous local anesthetics produce changes in sensorium and are often used to test newly placed epidural catheters. Many parturients receive nalbuphine for analgesia prior to epidural catheter placement. This study examines how nalbuphine premedication influences symptoms following intravenous 2-chloroprocaine. METHODS: Thirty-one volunteers were randomized to receive premedication with placebo or 0.15 mg/kg of nalbuphine intravenously. Starting 10 minutes later, intravenous injections of 0.0, 0.3, 0.6, 0.9, 1.2, and 1.5 mg/kg of 2-chloroprocaine were given in random order at 10 minute intervals. After each injection, volunteers were asked to report changes in hearing, taste, or other symptoms. RESULTS: Symptoms reported (in decreasing order of frequency) were auditory changes, taste changes, dizziness/ lightheadedness, tingling in the extremities, and visual changes. The probability that volunteers will report symptoms is proportional to the dose of 2-chloroprocaine administered (auditory symptoms, P < .001; taste symptoms, P = .01; any symptoms, P < .001). Nalbuphine-premedicated volunteers were more likely to report symptoms (auditory symptoms, P = .004; taste symptoms, P = .004; any symptoms, P = .02). A dose of at least 1.5 mg/kg appears to be necessary to produce a 90% probability that patients will report symptoms when they receive 2-chloroprocaine intravenously. CONCLUSIONS: This study suggests that patients who receive nalbuphine for analgesia prior to epidural placement will be more likely to report symptoms after receiving intravenous 2-chloroprocaine during epidural test dosing.

Anesthetic management of a parturient with an incompletely resected cerebral arteriovenous malformation.

BACKGROUND AND OBJECTIVES: The anesthetic, neurosurgical, and obstetric literature regarding management of parturients with intracranial arteriovenous malformations is relatively sparse. A case report is given of a parturient, with a recent subtotal resection of a cerebral arteriovenous malformation, who presented for delivery of a viable male fetus. METHODS: The patient was scheduled for an elective labor induction, with early epidural analgesia advocated as a strategy to minimize the cardiovascular changes of labor and prevent involuntary Valsalva maneuvers. An elective instrumental delivery was planned when the fetal head had descended appropriately. RESULTS: Epidural analgesia was initiated when the patient reached 3 cm cervical dilation and provided excellent labor analgesia. After a passive fetal descent during the second stage of labor, Luikart-Simpson forceps were used to facilitate this stage. The newborn Apgar score was 9 at both 1 and 5 minutes after delivery. Both the patient and the infant have done well. CONCLUSIONS: The available obstetric and neurosurgical literature does not offer firm recommendations for the optimal route of fetal delivery or the timing of neurosurgical resection of an arteriovenous malformation in the parturient. Anesthetic management is predicated on the principles of minimizing the cardiovascular changes of labor and preventing involuntary Valsalva maneuvers during the second stage of labor. Both of these goals are readily accomplished with epidural anesthesia.

Spinal anesthesia versus intravenous sedation for transvaginal oocyte retrieval: reproductive outcome, side-effects and recovery profiles.

Transvaginal ultrasonically guided oocyte retrieval is commonly performed as part of in vitro fertilization efforts. The impact of anesthetic management on patient outcome from this procedure has not been well characterized. At our institution, patients are offered a choice of either heavy intravenous sedation or spinal anesthesia with minimal or no sedatives. In this pilot study, we retrospectively reviewed the anesthetic management, reproductive outcome and recovery room experience for all patients having oocyte retrieval during a 2-year interval (n = 95). Fifty-one oocyte retrievals were performed under spinal anesthesia, while 44 patients received solely intravenous sedatives. Both groups had similar reproductive outcomes. The intravenous sedation group required a significantly longer period until recovery room discharge criteria were met (P = 0.03), and were more likely to have postoperative emetic episodes (46% versus 6% in the spinal anesthesia group: P < 0.01). Two unplanned hospital admissions occurred in the intravenous sedation group: both were related to uncontrolled nausea and vomiting. We conclude that spinal anesthesia may have advantages over intravenous sedation for oocyte retrieval.

Analgesic efficacy and side effects of subarachnoid sufentanil-bupivacaine administered to women in advanced labor.

BACKGROUND AND OBJECTIVES: Previous studies of labor analgesia using subarachnoid sufentanil (alone or with adjuvants) have focused on women in the early first stage of labor. This study prospectively evaluated analgesia and side effects of subarachnoid sufentanil (10 micrograms) plus bupivacaine (2.5 mg) in parturients with cervical dilation of 7 cm or more. METHODS: In an open-label, nonrandomized trial, 32 parturients in the late first stage of labor, who had requested regional anesthesia, consented to subarachnoid injection of sufentanil (10 micrograms) and bupivacaine (2.5 mg). Patients rated their pain by a verbal pain score (0-10 scale) prior to regional anesthesia, 5 minutes after subarachnoid injection, and every 20 minutes thereafter until delivery or request for additional analgesia. Blood pressure, pruritus, Bromage motor block score (0-3), mode of delivery, and need for supplemental analgesics were recorded. RESULTS: Lumbar puncture was successful in 30 women. Pain scores (mean +/- SD) were 8.7 +/- 1.0 prespinal and 0.7 +/- 1.5 5 minutes postinjection, and remained less than 5 for 130 minutes after the spinal injection. Of these 30 patients, 24 had unassisted vaginal delivery, 4 had instrumental vaginal delivery (3 vacuum, 1 low forceps), and 2 had cesarean delivery. Of the 28 patients who delivered vaginally, 19 did not require supplemental analgesics and had a delivery pain score of 5 or lower. Blood pressure decreased after spinal analgesia (P < .05), and necessitated treatment in three patients. The Bromage motor block score was 0 in 26 patients and 1 in 4 patients. Pruritus was noted by 22 patients. CONCLUSION: In parturients with cervical dilation of 7 cm or more, subarachnoid sufentanil-bupivacaine produces rapid analgesia with an effective duration of approximately 130 minutes.

Medial and lateral antebrachial cutaneous nerve blocks: an easily learned regional anesthetic for forearm arteriovenous fistula surgery.

BACKGROUND AND OBJECTIVES: Forearm arteriovenous fistula insertion is commonly performed to facilitate hemodialysis. This study was undertaken to assess the use of medial and lateral antebrachial cutaneous nerve blocks to provide anesthesia for this surgery. METHODS: Twelve patients with end-stage renal failure, presenting for insertion or revision of a forearm Gortex arteriovenous fistula, were anesthetized by local block of the medial and lateral antebrachial cutaneous nerves with a mepivacaine-bupivacaine mixture. RESULTS: Ten patients required no further local anesthetic for surgery. Two patients required minor local anesthetic supplementation in the proximal radial nerve distribution. CONCLUSIONS: Anesthesia for forearm arteriovenous fistula insertion can be provided by an easily performed regional anesthetic technique, which may have advantages over brachial plexus blocks and incisional field blocks.

Spinal anesthesia for repair of meningomyelocele in neonates.

The use of spinal anesthesia for meningomyelocele repair in neonates has received minimal attention. Spinal anesthesia may lessen the stress response to surgery and decrease postoperative respiratory complications. We therefore examined the efficacy of spinal anesthesia in 14 neonates requiring repair of lumbar or sacral meningomyelocele. All neonates were positioned prone with a small chest roll. Hyperbaric 0.5% tetracaine with epinephrine was injected into the caudal end of the meningomyelocele sac. If necessary, supplemental tetracaine was administered directly into the intrathecal space by the surgeon during the operation. Blood pressure, heart rate, and oxyhemoglobin saturation were measured throughout surgery. Neonates were monitored with transthoracic impedance apnea monitors, electrocardiogram (ECG), and pulse oximetry for 36 h after surgery. Spinal anesthesia was successful in all cases. Seven patients received one supplemental tetracaine injection; one patient received two supplemental injections. Arterial blood pressure decreased an average of 5 mm Hg with the largest decrease being 10 mm Hg. Two postoperative respiratory events occurred in the first 8 h after surgery. Both neonates had received intraoperative midazolam for sedation. Neurologic function was assessed pre- and postoperatively. Twelve patients had no change in neurologic function after surgery, while two infants demonstrated improved function. We conclude that spinal anesthesia can be safely used for meningomyelocele repair.

Labor epidural catheter reactivation or spinal anesthesia for delayed postpartum tubal ligation: a cost comparison.

STUDY OBJECTIVES: To evaluate the costs and resource consumption associated with utilizing epidural catheters placed during labor versus spinal anesthesia for postpartum tubal ligation. To examine maternal demographics, anesthetic management variables, and time interval from delivery until surgery for association with epidural catheter reactivation success rate. DESIGN: Retrospective study. SETTING: University hospital labor and delivery center. PATIENTS: 120 consecutive postpartum patients with tubal ligations performed between June 1991 and December 1993. INTERVENTIONS: Postpartum women scheduled for tubal ligation with labor epidural catheters in place either had local anesthetic injected via the epidural catheter (n = 45) or had the catheter removed without reinjection and spinal anesthetic administered (n = 20). Patients with inadequate epidural anesthesia went on to receive spinal anesthesia. Women without a labor epidural catheter received spinal anesthesia (n = 55). MEASUREMENTS AND MAIN RESULTS: Adequate anesthesia for tubal ligation was achieved in 78% of women after reinjection of their epidural catheter. Operating room (OR) and anesthesia times were highest when epidural catheter reactivation was unsuccessful, intermediate when epidural catheter reactivation was successful, and lowest with initial spinal anesthesia (p < 0.05). The longer OR and anesthesia provider times associated with epidural catheter reactivation increased patient charges on average of $176 compared with the initial use of spinal anesthesia. CONCLUSIONS: Spinal anesthesia for postpartum tubal ligation was associated with lower anesthesia professional fees and OR charges compared with attempted reactivation of epidural catheters placed during labor. Anesthesiologists should weigh the cost advantages of spinal anesthesia against the small, but increased probability of headache after dural puncture.