Anesthesia and analgesia
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Anesthesia and analgesia · Jul 1989
Randomized Controlled Trial Clinical TrialIncidence of visceral pain during cesarean section: the effect of varying doses of spinal bupivacaine.
The safety of 0.5% hyperbaric bupivacaine, as well as the incidence and severity of visceral pain, were evaluated in 36 women undergoing elective cesarean section under spinal anesthesia who, randomly divided into two groups, received different dose ranges according to height, 7.5-10 mg in group A and 10-12.5 mg in group B. When sensory block to at least the fourth thoracic dermatome was established, surgery was begun and the occurrence and severity of visceral pain recorded (visual analog scale) by an observer unaware of patient data. The level of analgesia to pinprick was determined when and if there was onset of pain intraoperatively, and supplementary medication was administered as needed. ⋯ In patients experiencing moderate to severe pain, the mean time between induction of anesthesia and onset of pain was similar in both groups, as was the amount of systemic narcotic given. Total time for regression of sensory analgesia to L5 was longer in patients in group B (243.9 versus 195.4 min), and the incidence of complete motor blockade was greater in group B. Increasing the amount of 0.5% hyperbaric bupivacaine per spinal segment reduces the occurrence of moderate to severe visceral pain during elective cesarean section without jeopardizing mother or fetus.
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Anesthesia and analgesia · Jul 1989
Comparative StudyHemodynamic and cardiodynamic effects of propofol and etomidate: negative inotropic properties of propofol.
The hemodynamic effects of an induction dose of propofol, 2.5 mg/kg, or etomidate, 0.3 mg/kg, were studied in eight dogs. In addition, cardiodynamic changes were measured using a left ventricular catheter and needle force probes. Propofol was associated with significant decreases in systolic (19.9%) and diastolic (25.3%) arterial pressures associated with a 17.3% decrease in cardiac output (CO) and a 11.6% reduction in systemic vascular resistance (SVR) without change in pulmonary capillary wedge pressure (PCWP). ⋯ Signals generated by the force probes in the left ventricular myocardium showed a significant reduction (16.3%) in left ventricular force (LVF) and a decrease in early systolic rates of increase in force (dF/dt max) by 23.5% associated with propofol. In the presence of an unchanged preload, an unchanged HR, and a decreased SVR, the reduction in CO suggests that propofol has a negative inotropic effect. This negative inotropic effect was confirmed by a reduction in LVF and dF/dt max.
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A technique for blocking the dorsal nerves of the penis was designed after reevaluation of the gross anatomy of the subpubic space and penis in children. The technique consists of inserting a short bevel needle in the two compartments of the subpubic space, where the nerves run before entering the base of the penis, and of injecting a small volume (0.1 mL/kg of body weight) of local anesthetic. This two-puncture procedure was prospectively evaluated in 100 children undergoing surgery of the penis under light general anesthesia. ⋯ No complications occurred and anesthesia was satisfactory for completion of surgery. The duration of postoperative pain relief was significantly longer in patients given bupivacaine than in those given lidocaine. It is concluded that the subpubic approach to the dorsal nerves of the penis is easy, safe, and reliable, and that 0.5% plain bupivacaine provides long-lasting postoperative pain relief.
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Anesthesia and analgesia · Jul 1989
Comparative StudyComparison of tracheal intubating conditions and neuromuscular blocking profiles after intubating doses of mivacurium chloride or succinylcholine in surgical outpatients.
Thirty ASA physical status I or II outpatients scheduled to undergo short procedures (less than 1 hr in duration) requiring tracheal intubation received either 1.0 mg/kg succinylcholine or 0.20 mg/kg (2.5 x ED95) or 0.25 mg/kg (3 x ED95) mivacurium. A N2O/O2/narcotic anesthetic technique was utilized and the ulnar nerve was stimulated with subcutaneous electrodes placed at the wrist. Tracheal intubation was attempted in all patients either 2 min after mivacurium or 1 min after succinylcholine. ⋯ The mean infusion rates were 6.6 micrograms.kg-1.min-1 mivacurium and 41.2 micrograms.kg-1.min-1 for succinylcholine. Spontaneous recovery from neuromuscular blockade occurred more quickly after succinylcholine than after mivacurium: the time from cessation of infusion to recovery of T1 to 95% of baseline was 6.5 min in patients given succinylcholine and 16.7 min in patients given mivacurium. When reversal was in order, residual mivacurium-induced blockade was readily antagonized by 0.045 mg/kg neostigmine.(ABSTRACT TRUNCATED AT 250 WORDS)
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Fifty-four patients developed severe intercostal neuralgia a few weeks after sternotomy. Immediate relief afforded by parasternal nerve blocks confirmed that the pain derived from scar-entrapped neuromas of the anterior rami of the first 4-6 intercostal nerves in the upper (and mainly left) interchondral spaces after insertion of the sternal wires. Permanent relief (i.e., over 6 months) followed repeated bupivacaine blocks in 57.4% of the patients, phenol blocks in another 22.2%, and alcohol blocks in a remaining 9%. Treatment was successful in 87% of the patients.