Anesthesiology
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Changes in oxygen consumption (VO2) and oxygen delivery (DO2) were compared in three groups of paralyzed, sedated dogs: 1) a group (n = 5) cooled to 29 degrees C and immediately rewarmed to 37 degrees C; 2) a group (n = 5) cooled to and maintained at 29 degrees C for 24 h, and then rewarmed; and 3) a group (n = 5) maintained at 37 degrees C for 24 h. During the cooling phase, in both the acute and prolonged hypothermia animals, VO2 and DO2 decreased significantly from control values (P less than 0.05). The decrease in DO2 occurred as a result of a similar decrease in cardiac index (CI; P less than 0.05) that was associated with a significant increase in systemic vascular resistance index (SVRI; P less than 0.05). ⋯ DO2 remained below control in both groups, resulting in a significant increase in O2 extraction (P less than 0.05) and a decrease in PVO2 (P less than 0.05) in the prolonged hypothermia animals. Following rewarming administration of sodium nitroprusside returned DO2, CI, and SVRI to control values but did not increase VO2. All animals survived the study without need for inotropic support.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of epidural and intramuscular morphine in patients following cesarean section.
This randomized, double-blind study compared epidural (EP) and intramuscular (IM) morphine in 24 healthy parturients for 24 h after cesarean section. The 11 EP subjects received 5 mg of EP morphine and normal saline intramuscularly, and the 13 IM patients received 5 mg of IM morphine and normal saline epidurally. Both injections were given simultaneously just after delivery and then upon request with at least 30 min between each pair of injections. ⋯ There were no major respiratory abnormalities. During control monitoring of nine EP and 11 IM subjects while asleep postoperatively, the RR, Spo2, and incidence and frequency of SRR and AP were similar to the study period in both groups. In conclusion, EP morphine was a more effective analgesic than IM morphine, but the side effects of both were similar.
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Randomized Controlled Trial Clinical Trial
Metoclopramide reduces the incidence of vomiting following strabismus surgery in children.
This randomized, double-blind study evaluated the efficacy of metoclopramide administered at the completion of surgery as an antiemetic agent in pediatric patients undergoing ambulatory strabismus surgery; 126 unpremedicated ASA Physical Status 1 and 2 children ranging in age from 2 to 18 yr served as subjects. All received general anesthesia with halothane, N2O, and O2; tracheal intubation was facilitated with intravenous (iv) atracurium 0.5 mg/kg. Intravenous atropine 0.02 mg/kg and lactated Ringer's solution with 5% dextrose equivalent to 4 h of maintenance fluids were administered during surgery. ⋯ A research associate monitored the children for the incidence of post-operative vomiting and the time required for each child to meet discharge criteria from Short Stay Recovery Unit (SSRU). If a child vomited more than three times in both the PARR and SSRU, the vomiting was construed to be severe and the patient was offered further antiemetic treatment with iv droperidol 70 micrograms/kg. The incidence of postoperative vomiting in the metoclopramide group was 37% versus 59% in the placebo group (P less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)
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The purpose of this study was to determine whether prior administration ritodrine worsens maternal hypotension during epidural anesthesia in gravid ewes. Twenty-four experiments were performed in nine chronically instrumented animals between 0.8 and 0.9 of timed gestation. The experimental sequence included the following: 1) at time-zero, intravenous (iv) administration of ritodrine, 0.004 mg.kg-1.min-1, or normal saline (NS) for 2 h; 2) at 120 min discontinuation of ritodrine, and administration of a 500 ml iv bolus of NS over 15 min; and 3) at 135 min epidural injection of 2% lidocaine or NS. ⋯ Cardiac output remained above baseline (P less than 0.01) after epidural injection of lidocaine in the ritodrine-lidocaine group. In contrast, in the NS-lidocaine group cardiac output was 13 +/- 5% below baseline (P = 0.005) at 150 min. Fetal arterial pH did not change significantly in either the ritodrine-lidocaine or ritodrine-NS group.(ABSTRACT TRUNCATED AT 250 WORDS)