Spinal anesthesia for cesarean section: isobaric versus hyperbaric solution.

BACKGROUND: The present study was undertaken to compare the outcomes of hyperbaric versus isobaric spinal anesthesia in Cesarean delivery. METHODS: The anesthetic solution was administered in sitting position as this posture is commonly used in this clinical setting. Except for the baricity of the anesthetic solution, identical technique was employed for every parturient in the study. Following administration of anesthetic solution the parturient immediately resumed horizontal supine position. The solutions used were 2.0 mL of 0.5% tetracaine in 5% dextrose (hyperbaric) for Group H (n = 30) and in cerebrospinal fluid (isobaric) for Group I (n = 30). RESULTS: Both hyperbaric and isobaric tetracaine given in sitting position provided adequate analgesic levels. However, hyperbaric tetracaine solution produced a slightly higher median peak level of wilder range, and caused a higher incidence of hemodynamic changes and subjective sensation of "feeling sick" than isobaric tetracaine. Additionally, the duration of surgical anesthesia was shorter and the sacral block was longer for hyperbaric tetracaine solution than for isobaric tetracaine solution at same dose and concentration. Only one mother in Group H needed supplemental inhalation anesthesia for a subsequent hysterectomy due to uncontrollable bleeding. There were no complications, including postpuncture headache in either group. CONCLUSIONS: Our results indicated that numerous variables must be taken into consideration in predicting the outcome of a spinal anesthesia. Alternation in the technique and individual patient factor may individually or collectively produce different results.

Effect of subarachnoid morphine on the incidence of spinal headache.

BACKGROUND AND OBJECTIVES: The addition of fentanyl to hyperbaric local anesthetics has been shown to reduce the incidence of post dural puncture headache in the obstetric patient. This study was undertaken to evaluate the effects of subarachnoid morphine on the incidence of headache. METHODS: Eighty-two healthy patients undergoing cesarean delivery with spinal anesthesia were studied. All patients were hydrated with 1500 ml lactated Ringer's solution. Patients were randomly assigned to receive, in a double-blind fashion, 0.2 mg of either morphine (Group 1, n = 40) or saline (Group 2, n = 42) in 0.2 ml volume mixed with 0.75% bupivacaine in 8.25% dextrose plus 0.2 ml 1:1000 epinephrine. Spinal anesthesia was induced using a 25-gauge spinal needle at L3-4 interspace with the bevel, in most cases, parallel to the dural fibers. Patients were followed for three days to evaluate the incidence and severity of headache using a four-category rank scale (none, mild, moderate, severe). Data were analyzed for statistical significance using Student's t-test or chi-square test as appropriate. A p value less than 0.05 was considered significant. Results. The incidence of post dural puncture headache did not differ significantly between groups. Eight patients in Group 1 versus nine patients in Group 2 developed headache (p greater than 0.05). Similarly, the use of blood patch or intravenous caffeine sodium benzoate to treat the headache did not differ significantly between groups. CONCLUSION: It is concluded from our study that subarachnoid morphine did not decrease the incidence of post dural puncture headache in the obstetric patient.

Epidural butorphanol augments lidocaine sensory anesthesia during labor.

To determine the efficacy and safety of epidural butorphanol combined with lidocaine, 50 healthy parturients were studied during labor and delivery. All patients received a test dose of 3 ml 1.5% lidocaine with 1:200,000 epinephrine. Patients were then randomly assigned to receive 7 ml of one of two epidural regimens in a double-blind fashion: Group 1 patients received 1.5% lidocaine plus 1 mg butorphanol plus 1:300,000 epinephrine; Group 2 patients received 1.5% lidocaine plus 1:300,000 epinephrine. Each group consisted of 25 patients. The study ended at the time of redosing. All subsequent epidural injections were made with one bolus of plain 0.25% bupivacaine followed by continuous infusion of 0.125% bupivacaine. Duration of anesthesia was significantly longer for Group 1 compared to Group 2 (p less than 0.01), 124 +/- 8 minutes versus 99 +/- 6 minutes (mean +/- SEM). There were no difference between groups in duration of first and second stages of labor, method of delivery or neonatal outcome. Umbilical cord acid-base status and neurologic adaptive capacity scores did not differ significantly between the two groups. The authors conclude that adding small doses of butorphanol to epidural lidocaine during labor is effective and safe.

Continuous infusion epidural anesthesia during labor: a randomized, double-blind comparison of 0.0625% bupivacaine/0.002% butorphanol and 0.125% bupivacaine.

The efficacy of pain relief and the maternal and neonatal effects of continuous epidural infusion of 0.0625% bupivacaine/0.002% butorphanol was compared with the infusion of 0.125% bupivacaine alone in a randomized, double-blind study of 32 women in labor. A test dose of 2 ml 0.5% bupivacaine was given to every patient and followed by two epidural regimens in randomized, double-blind manner. Group B-B (bupivacaine/butorphanol) patients received 7.5 ml 0.125% bupivacaine plus 1 mg butorphanol (0.5 ml) followed by an infusion of 0.0625% bupivacaine/0.002% butorphanol at a rate of 12 ml/hour; Group B (bupivacaine alone) patients received 8 ml 0.25% bupivacaine followed by an infusion of 0.125% bupivacaine at a rate of 12 ml/hour. A bolus of 5 ml 0.125% bupivacaine or 0.0625% bupivacaine was given to Group B or B-B, respectively, if additional pain relief was required. Infusion of B-B combination resulted in similar pain relief and fewer patients with motor block than bupivacaine alone; 12% versus 38% in Groups B-B and B, respectively, had motor weakness. A smaller dose of bupivacaine was used in the B-B group compared to the B group; 71 +/- 14 versus 99 +/- 13 mg (mean +/- SEM; p less than 0.05). Progress of labor and the mode of delivery did not differ significantly between the two groups. All infants were vigorous and had normal acid-base status and neurologic adaptive capacity scores. Butorphanol appears to be useful as an adjunct to epidural bupivacaine for continuous epidural infusion during labor without adversely affecting the mother or the neonate.

Prophylactic oral naltrexone with intrathecal morphine for cesarean section: effects on adverse reactions and analgesia.

The influence of two different doses of oral naltrexone on the adverse effects and the analgesia associated with intrathecal morphine was compared in a double-blind, placebo-controlled study. Thirty-five patients undergoing cesarean section were provided postoperative analgesia by 0.25 mg intrathecal morphine. Sixty minutes later they were given 6 mg naltrexone, 3 mg naltrexone, or placebo as an oral solution. Pain relief was assessed by the Visual Analog Scale. Requirements for additional analgesics and side effects were recorded. Duration of analgesia was shorter in the 3- and 6-mg naltrexone groups than in the placebo group, 10.0 +/- 2.6, 12.4 +/- 2.6, and 19.2 +/- 4.5 h (mean +/- SEM), respectively, but values did not reach statistical significance. The incidence of pruritus and vomiting was significantly less in the 6-mg naltrexone group than in the other two groups (P less than 0.05). Somnolence was significantly less in the 3- and 6-mg naltrexone groups than in the placebo group (P less than 0.05). Naltrexone (6 mg) is an effective oral prophylactic against the pruritus and vomiting associated with intrathecal morphine for analgesia after cesarean section, but it is associated with shorter duration of analgesia.

Prophylactic oral naltrexone with epidural morphine: effect on adverse reactions and ventilatory responses to carbon dioxide.

The influence of two different doses of oral naltrexone on the adverse effects and the analgesia of epidural morphine were compared in a double-blind, placebo-controlled study. Forty-five patients undergoing cesarean section were provided postoperative analgesia with 4 mg epidural morphine. Five minutes later they received 6 mg naltrexone, 9 mg naltrexone, or placebo as an oral solution. Pain relief was assessed by the Visual Analog Scale (VAS) and by direct questioning of the patients. Requirement for additional analgesics and side effects were noted. Respiratory effects of epidural morphine and naltrexone were assessed using the ventilatory responses to CO2 and by monitoring O2 saturation (Spo2) using pulse oximetry. All patients in the placebo group had adequate analgesia. One of the 15 patients who received naltrexone 6 mg had inadequate analgesia versus five of the 15 patients who received naltrexone 9 mg (P less than 0.05), 9 mg versus placebo. Ten patients (67%) in the placebo group had pruritus while no patient in the 6 mg naltrexone group and one patient in the 9 mg group experienced mild pruritus (P less than 0.05), placebo versus other two groups. The CO2 response slopes were depressed compared to control values from 6-16 h in the placebo group, from 6-12 h in the 6 mg naltrexone group. No significant depression was noted in the 9 mg naltrexone group. The authors conclude that oral naltrexone 6 mg significantly reduces the incidence of pruritus associated with epidural morphine without affecting analgesia and that 9 mg naltrexone is associated with shorter duration of analgesia than 6 mg naltrexone.

Bupivacaine/butorphanol/epinephrine for epidural anesthesia in obstetrics: maternal and neonatal effects.

The effects of epidural bupivacaine/butorphanol with and without 1:300,000 epinephrine on maternal analgesia, uterine activity, progress of labor, fetal heart rate, maternal blood pressure, newborn Apgar scores, neonatal acid base status and the neurologic and adaptive capacity scores (NACS) were compared in 33 parturients during labor and delivery. Patients in Group I (n = 17) received 0.25% bupivacaine plus 1 mg butorphanol plus 1:300,000 epinephrine, and those in Group II (n = 16) received the same agents without the epinephrine. Addition of epinephrine to bupivacaine/butorphanol did not have any adverse effects on uterine activity, duration of first or second stages of labor or fetal heart rate parameters. The incidence of maternal hypotensive episodes did not differ significantly between the two groups of patients. Apgar scores, neonatal acid base status and the NACS were equally good and did not differ significantly between the two groups. Duration of analgesia was significantly longer in Group I as compared to Group II patients (177.5 +/- 11 versus 131.8 +/- 10 minutes, p less than 0.01). It is concluded that addition of epinephrine 1:300,000 to bupivacaine/butorphanol during epidural anesthesia in the normal parturient has no adverse effects on the mother, fetus or neonate or on the progress of labor and it significantly prolongs the duration of analgesia.