Anesthesia and analgesia
-
Anesthesia and analgesia · Nov 1985
Fentanyl pharmacokinetics and hemodynamic effects in preterm infants during ligation of patent ductus arteriosus.
A bolus of 30 micrograms X kg-1 fentanyl was given to nine preterm infants (gestational age 31.8 +/- 4.7 weeks, weight 1100 +/- 309 g) for induction of anesthesia for ligation of a patent ductus arteriosus. Thirty minutes after the injection, fentanyl plasma concentrations were between 7.7 and 13.6 ng X ml-1. Elimination half-life was 6-32 hr (mean +/- SD, 17.7 +/- 9.3). ⋯ There was a gradual increase in heart rate from 159 +/- 12 min-1 at the time of skin incision to 173 +/- 15 min-1 at the time of skin closure (P less than 0.05). Fentanyl plasma concentrations remained virtually unchanged between 30 min (10.6 +/- 1.9 ng X ml-1) and 120 min (9.6 +/- 1.6 ng X ml-1); whereas at the end of surgery most infants moved and breathed spontaneously. This phenomenon can be explained by redistribution of fentanyl from brain into pharmacodynamically inert tissues.
-
Anesthesia and analgesia · Oct 1985
Randomized Controlled Trial Clinical TrialInhibition of postoperative pain by continuous low-dose intravenous infusion of lidocaine.
Intravenous lidocaine has been reported previously to inhibit postoperative pain when given either as single injections or as short infusions in amounts usually causing adverse reactions. To determine the efficacy of a continuous low-dose (2 mg/kg) intravenous infusion of lidocaine, postoperative pain (visual analogue pain scale) and the requirements for postoperative analgesics were measured in a double-blind randomized trial in 20 patients after cholecystectomy. Lidocaine infusion was started 30 min before the operation and continued for 24 hr after surgery (n = 10). ⋯ No adverse reactions to lidocaine were observed. Whole blood levels of lidocaine ranged between 1 and 2 micrograms/ml. The results suggest that low-dose continuous infusions of lidocaine decrease the severity of postoperative pain and are devoid of side effects.
-
Anesthesia and analgesia · Oct 1985
Comparative StudyHalothane and isoflurane do not decrease PaO2 during one-lung ventilation in intravenously anesthetized patients.
We examined the effect of the inhalational anesthetics halothane (H) and isoflurane (IF) on arterial oxygenation during one-lung ventilation. Twenty consenting patients who required thoracotomy and one-lung ventilation were initially anesthetized only with the intravenous agents, diazepam, fentanyl, pancuronium, metocurine, and infusions of either ketamine or methohexital. A double lumen endotracheal tube was inserted, and each patient's lungs were mechanically ventilated (two-lung ventilation, step 1) with 100% O2 while the patient was in the lateral decubitus position. ⋯ The inhalational anesthetics were then discontinued, and intravenous agents were reinstituted, allowing PETH and PETIF to decrease below 0.50 mm Hg (step 4). Two-lung ventilation was resumed at the end of the surgical procedure (step 5). PaO2 decreased from 441 +/- 64 to 252 +/- 70 mm Hg when one-lung ventilation was achieved (steps 1-2), and PaO2 increased from 258 +/- 72 to 395 +/- 65 mm Hg when two-lung ventilation was resumed (steps 4-5).(ABSTRACT TRUNCATED AT 250 WORDS)
-
Anesthesia and analgesia · Oct 1985
Antiarrhythmic effect of diltiazem during halothane anesthesia in dogs and in humans.
The antiarrhythmic effects of diltiazem (DL), a slow channel inhibitor, were evaluated in the presence of epinephrine-halothane-induced arrhythmias in dogs, of premature ventricular contractions (PVCs) during anesthesia in patients (n = 10), and of tachyarrhythmias with associated atrial fibrillation (AF) during anesthesia in patients (n = 9). The arrhythmogenic dose of epinephrine (ADE) during one MAC of halothane in dogs was increased from 1.13 +/- 0.21 to 3.14 +/- 0.89 microgram X kg-1 X min-1 by the administration of 0.3 mg/kg of DL. This suggests that DL significantly increases the threshold for the induction of arrhythmias associated with epinephrine and halothane. ⋯ With an additional nine patients who had had AF preoperatively and suffered tachyarrhythmias during anesthesia, the intraoperative intravenous administration of DL significantly decreased heart rate (to less than 100 beats/min) within 10-15 min. Diltiazem is an effective means for the treatment of PVCs and AF-mediated tachyarrhythmias during anesthesia. Because of the pharmacologic properties of DL (e.g., depressing sinus and atrioventricular (AV) node function), DL should be used with caution in patients with a sick sinus syndrome or an AV block, or in the presence of beta-adrenergic antagonists.
-
Anesthesia and analgesia · Oct 1985
Comparative StudyComparison of the requirements for hepatic injury with halothane and enflurane in rats.
A rat model of enflurane-associated hepatotoxicity was compared with the halothane-hypoxia (HH) model (adult male rats, phenobarbital induction, 1% halothane, 14% O2, for 2 hr). The enflurane-hypoxia heating (EHH) model involved exposing phenobarbital-pretreated male adult rats to 1.5-1.8% enflurane at 10% O2 for 2 hr with external heating to help maintain body temperature. Exposure to either anesthetic without temperature support led to a decrease in body temperature of 7-9 degrees C, while heating the animals during anesthesia resulted in only a 0.5-2 degree decrease. ⋯ The HH model required phenobarbital pretreatment of the rats for expression of hepatic injury; EHH did not. Heating of the animals during anesthesia exposure was necessary for enflurane-induced hepatoxicity but had little effect on the HH model. Exposure to 5% O2 without anesthetic mimicked EHH in both requirements for and type of hepatic injury.