H. Adriaensen

Prevention of hypotension by a single 5-mg dose of ephedrine during small-dose spinal anesthesia in prehydrated cesarean delivery patients

To evaluate the effectiveness of prophylactic ephedrine for the prevention of hypotension associated with spinal anesthesia, 50 parturients undergoing cesarean delivery received either ephedrine 5 mg or saline IV in a double-blinded fashion immediately after the induction of spinal anesthesia. Spinal anesthesia was performed with hyperbaric bupivacaine 6.6 mg combined with sufentanil 3.3 &mgr;g as part of a combined spinal-epidural technique. All patients received 1000 mL of lactated Ringer’s solution and 500 mL of hydroxyethylstarch 6% before the spinal injection. Additional ephedrine boluses (5 mg) were administered IV when the systolic blood pressure or heart rate decreased by more than 30% from baseline values, when systolic blood pressure became <100 mm Hg, or when patients complained of nausea or feeling faint. The height of the block was equal in the groups; however, more patients in the placebo group were found to develop hypotension (58% vs 25%, P < 0.05). Only 2 (8%) patients in the ephedrine group developed hypotension with systolic blood pressure values <90 mm Hg, whereas 10 patients (42%) in the saline group experienced hypotension of this severity (P < 0.05). In addition, there was a higher incidence of nausea in the placebo-treated patients. The total amount of ephedrine administered did not differ between groups. These findings suggest that the incidence and severity of hypotension are significantly reduced by the IV administration of a prophylactic dose of 5 mg ephedrine in patients receiving small-dose spinal anesthesia for cesarean delivery. Implications Ephedrine is the drug most often used to correct hypotension during spinal anesthesia for cesarean delivery in healthy patients. A single IV dose of 5 mg decreases the occurrence and limits the severity of hypotension in prehydrated subjects receiving a small-dose spinal local anesthetic-opioid combination.

Small-dose hyperbaric versus plain bupivacaine during spinal anesthesia for cesarean section.

In a double-blind, randomized trial, 98 parturients undergoing cesarean section received either hyperbaric or plain bupivacaine 6.6 mg combined with sufentanil 3.3 [micro sign]g as part of a combined spinal-epidural procedure. To prevent hypotension, 1000 mL of lactated Ringers solution, 500 mL of hydroxyethyl starch 6%, and ephedrine 5 mg were administered IV. The height of the block was equal in both groups, but more patients in the plain group had blocks that were either too high or too low (P < 0.01). The number of patients requiring epidural supplementation was equal in both groups. Strict criteria were used to treat hypotension. The overall incidence of systolic blood pressure (<90 mm Hg) was 13%, whereas it was more pronounced in the plain group (21% vs 6% in the hyperbaric group, P < 0.05), which required more ephedrine (P < 0.05) and in which a greater incidence of nausea was noticed (P < 0.05). We conclude that the use of a small dose of intrathecal bupivacaine combined with sufentanil plus our described preloading regimen resulted in a lower incidence of hypotension. Further, we conclude that the use of hyperbaric bupivacaine in this manner provides a more reliable block and a lower incidence of hypotension than plain bupivacaine. Implications: A small dose of hyperbaric bupivacaine 0.5% combined with sufentanil used intrathecally during cesarean section offered a more reliable cephalad spread of the spinal block than the glucose-free combination, which was reflected in a lower incidence of hypotension and nausea. (Anesth Analg 1998;86:989-93)

Levobupivacaine combined with sufentanil and epinephrine for intrathecal labor analgesia: a comparison with racemic bupivacaine.

We performed a randomized, double-blinded study to compare levobupivacaine with racemic bupivacaine for labor analgesia. Eighty term parturients received either levobupivacaine 0.125% or racemic bupivacaine 0.125%, to which was added sufentanil 0.75 &mgr;g/mL and epinephrine 1.25 &mgr;g/mL. As part of a combined spinal-epidural procedure, 2 mL of this mixture was initially injected intrathecally, and the same solutions were subsequently administered epidurally. For both combinations, onset until the first painless contraction was 4 to 5 min. Most patients were pain free during the second contraction. The duration of initial spinal analgesia was 93.5 ± 20 min and 94.7 ± 31 min for levobupivacaine and racemic bupivacaine, respectively. The duration of analgesia for the first epidural top-up dose was also similar in the two groups. Total local anesthetic requirements during labor were not different. The only major difference observed was the absence of motor impairment in levobupivacaine-treated parturients as compared with the Racemic Bupivacaine group, in which the incidence of a Bromage-1 motor block was 34%. Other side effects and obstetric or neonatal outcomes were not different between groups. Intrathecal levobupivacaine has a similar clinical profile as racemic bupivacaine, but at equal doses it produced less motor block.

Epidural Sufentanil for Postoperative Patient-Controlled Analgesia (PCA) With or Without Background Infusion: A Double-Blind Comparison

To evaluate the usefulness of a concurrent infusion in patient-controlled epidural analgesia (PCEA), 40 patients scheduled for elective cesarean section under a combined spinal-epidural technique were assigned randomly in a double-blind fashion to receive sufentanil by PCEA with a concomitant infusion of either sufentanil or saline. The sufentanil 24-h consumption was significantly (P < 0.001) higher in those patients receiving the opioid-containing infusion (212.7 +/- 9.5 vs 128.4 +/- 10.8 micro gram, SEM). The number of additional demands and the quality of sleep did not differ between the two groups. The degree of sedation was significantly less pronounced in patients treated with incremental sufentanil doses only. The visual analog scale (VAS) pain scores at rest were identical in both groups except at 6 h (2.5 +/- 0.4 vs 3.7 +/- 0.3, in favor of the patients treated with the sufentanil background infusion). We conclude that, except for a lower pain score during the initial hours, a background infusion in PCEA with sufentanil does not offer major advantages in terms of sleep quality or sufentanil consumption. Side effects may be more pronounced owing to increased drug administration. (Anesth Analg 1995;80:76-80)

Intrathecal labor analgesia with bupivacaine and sufentanil: The effect of adding 2.25 μg epinephrine

Background and Objectives Epinephrine, 25 μg and 200 μg, has been found to prolong the duration of intrathecal labor analgesia when added to an opioid. In our hospital we use the standard epidural mixture, prepared by the pharmacist, containing epinephrine 1:800,000; i.e., 1.25 μg/mL for both spinal and epidural labor analgesia. We wanted to evaluate whether such a low dose, depending on its effect on duration or quality of analgesia, should be maintained or deleted in future mixtures. Methods Forty-five term parturients were randomly assigned to receive 1.8 mL intrathecally of a mixture containing bupivacaine 0.125% and sufentanil 0.75 μg/mL with or without epinephrine 1.25 μg/mL. The quality and duration of analgesia, side effects, and obstetric/neonatal outcome were compared. Results For both combinations, the onset until the first painless contraction was between 5 and 6 minutes. Most patients were pain free during the second uterine contraction. The duration of complete analgesia was 93.2 ± 24.2 minutes in the epinephrine group and 79.3 ± 18.1 minutes for patients not receiving epinephrine (P = .014). The quality of the block, bupivacaine consumption, side effects, and obstetric/neonatal outcome were not different between groups. Conclusions It was concluded that epinephrine in a dose as low as 2.25 μg significantly prolonged the duration of intrathecal analgesia of bupivacaine-sufentanil by 15 minutes. No other differences were noticed. Diluting the commercially available bupivacaine 0.5% with epinephrine 1:200,000 may avoid the need of freshly prepared epinephrine solutions.