Effects of succinylcholine on the recovery of block produced by mivacurium in rats.

This study investigates the effects of succinylcholine on the recovery of neuromuscular blockade produced by mivacurium in rats. In 48 anesthetized animals, the sciatic nerve was prepared and stimulated, and twitches of the flexor digitorum longus muscle were recorded. Animals were randomly divided into four groups (n = 12 each): bolus dose of succinylcholine 0.1 mg/kg (GroupSch), bolus dose of mivacurium 0.15 mg/kg (GroupMiv), bolus dose of mivacurium 0.15 mg/kg, followed by succinylcholine 0.1 mg/kg at 25% neuromuscular recovery from mivacurium (Group-MivSch(25)), or bolus dose of mivacurium 0.15 mg/kg, followed by succinylcholine 0.1 mg/kg at 75% neuromuscular recovery from mivacurium (GroupMivSch(75)). Onset times of neuromuscular block following succinylcholine in mivacurium-treated groups were comparable and significantly shorter than in GroupSch (p < 0.001). Duration of action of succinylcholine was more prolonged when it was given in the presence of deeper neuromuscular block induced by mivacurium (p < 0.001 in GroupMivSch(25) and p < 0.01 in GroupMivSch(75)). Our results suggest that, in rats, mivacurium administration has a significant potentiating effect on a subsequent succinylcholine-induced neuromuscular block.

Spontaneous rupture of the rectosigmoid with small bowel evisceration through the anus.

Spontaneous rupture of the rectosigmoid with small bowel evisceration through the anus is a rare and acute condition of the gastrointestinal tract. After Brodie's first description, only 52 such cases have been reported in the literature. An 83-year-old woman experienced a sudden, spontaneous rectosigmoid rupture and protrusion of small bowel loops, through the ruptured colon and out of the anus. After an immediate management, an emergency operation was performed, and a small bowel resection and suturing of the ruptured rectosigmoid were carried out for restoration of bowel continuity. On the 41st postoperative day, a massive cerebro-vascular accident (CVA) was the cause of the patient's death. Discussion of the aetiology and treatment of this rare condition.

Sufentanil or clonidine for blunting the increase in intraocular pressure during rapid-sequence induction.

BACKGROUND AND OBJECTIVE: The aim was to determine if the intravenous administration of sufentanil or clonidine before the induction of anaesthesia could obtund the increase of intraocular pressure associated with rapid-sequence induction. METHODS: Thirty-two ASA I-II patients with no history of eye illness scheduled for elective non-ophthalmic surgery were randomly assigned to receive either sufentanil 0.05 microg kg(-1) i.v. (Group A, n = 15) or clonidine 2 microg kg(-1) i.v. (Group B, n = 17) prior to induction. General anaesthesia was induced with thiopental (5 mg kg(-1)) followed by succinylcholine 1 mg kg(-1) to facilitate tracheal intubation. The general anaesthetic technique was standardized in both groups. Intraocular pressure was measured using the Schioetz tonometer just before the succinylcholine administration (t0), just before tracheal intubation (t1) and immediately after intubation (t2). Mean arterial pressure and heart rate were recorded at the same time intervals. RESULTS: Intraocular pressures were similar in both groups at t0, but the sufentanil group had significantly lower values compared with the clonidine group just before (t1) and immediately after tracheal intubation (t2). CONCLUSIONS: Sufentanil is effective in blunting the increase in intraocular pressure caused by rapid-sequence induction with succinylcholine, while clonidine did not seem to have any effect in intraocular pressures just before (t1) and just after (t2) intubation.

Tropisetron vs ondansetron for prevention of postoperative nausea and vomiting after laparoscopic cholecystectomy: a randomized double-blind, placebo-controlled study.

BACKGROUND: Postoperative nausea and vomiting are observed in increased frequency after laparoscopic surgery. This study was performed in order to compare the efficacy of two 5-hydroxytryptamine-3 (5-HT3) receptor antagonists, ondansetron and tropisetron, in preventing postoperative nausea and vomiting (PONV) after laparoscopic cholecystectomy. METHODS: Using a randomized, double-blind study design, 87 ASA I and II patients scheduled for laparoscopic cholecystectomy were randomly assigned to receive 4 mg ondansetron (Group A, n = 29), 5 mg tropisetron (Group B, n = 31), or placebo (Group C, n = 27) intravenously (IV) before induction of anesthesia. The end points evaluated were frequency of nausea, nausea intensity rated on a scale from 1 (mild) to 5 (most severe), frequency of vomiting, and need for rescue antiemetics. These parameters were measured immediately after surgery (0 h), at 3 h, 6 h, and 12 h postoperatively. RESULTS: The frequency of nausea was significantly higher in group A (31.2%) compared to group B (14%) at 12 h postoperatively (p <0.01). However, patients of group A had significantly lower nausea scores at 3 h postoperatively compared to group B. Postoperative vomiting occurred in 13.8% of patients in group A and 9.6% of patients in group B throughout the whole study period (p = n.s.). The need for rescue antiemetics was similar between groups A and B. Both groups were superior to placebo concerning all studied parameters. CONCLUSION: Our results show that ondansetron may be more effective in controlling nausea intensity during the first 3 h after laparoscopic cholecystectomy, while tropisetron has a longer-acting activity, with a major impact on nausea frequency at 12 h postoperatively.

Effect of succinylcholine on the neuromuscular junction of hypoglycemic rats.

The aim of the present study was to investigate the effect of neuromuscular blocking drugs on the neuromuscular junction in hypoglycemic rats. Three groups of 6 white adult Wistar albino rats were used. Group A consisted of the control animals with normal blood glucose levels ranging between 80-120 mg/dl. Groups B and C consisted of animals which were made hypoglycemic by intravenous injection of insulin at a dose of 1 iU/100 g b.w. In this way, their blood glucose levels were reduced to 50% of the blood glucose levels of the control animals. The test animals (groups B and C) were sacrificed 40 min after the injection of insulin and the preparations of the phrenic nerve-hemidiaphragm were placed into a 100 ml_bath containing Paradelis-Zaimis solution. The bath was aerized with O2/CO2:95/5%, it's temperature was maintained at 37 degrees C and it's pH at 7.2. After the stabilization of the system and the recording of neuromuscular activity, succinylcholine was administered (1.5 x 10(-8) M in groups A and B and 3.0 x 10(-8) M in group C). For the statistical analysis of the results, student's t-test was used. According to our results, there is a statistically significant difference (with p < 0.02 being considered significant) between the n.bl/t% (magnitude of final neuromuscular blockage) values of the animals of groups B and C and those of the animals of group A. We also observed a statistically significant difference (with p < 0.001 being considered significant) between the t (time required for complete blockage in groups A and C or time required for stabilization of blockage in group B) values of the animals of groups B and C and those of the animals of group A. On the other hand, there was a statistically significant difference (p < 0.02 being considered significant) in the n.bl/5'% (magnitude of neuromuscular blockage 5 min after the administration of succinylcholine) values only between the animals of group A and B. Our results indicate that under hypoglycemic conditions, the amount of succinylcholine required for final neuromuscular blockage is two times greater than that needed under normal glucose blood levels. This finding suggests that the integrity of the neuromuscular junction is altered during hypoglycemia.