PREJUNCTIONAL SUPPRESSION OF SUCCINYLCHOLINE INDUCED FASCICULATIONS BY ATRACURIUM IN THE CAT

Effect of sedation and analgesia on postoperative amplitude-integrated EEG in newborn cardiac patients

The aim of this study is to describe the effect of sedation and analgesia on postoperative amplitude-integrated EEG (aEEG) in newborns with congenital heart disease (CHD) undergoing heart surgery. This is a consecutive series of 26 newborns with CHD of which 16 patients underwent cardiopulmonary bypass (CPB) surgery and 10 patients did not. aEEG was monitored for at least 12 h preoperatively and started within the first 6 h postoperatively for 48 h. Outcome was assessed at 1 year of age. All 26 patients showed a normal preoperative continuous cerebral activity with sleep-wake cycles (SWC). The postoperative duration to return to normal background activity with SWC was similar for both groups. Independent of group assignment, patients requiring midazolam had a significantly later onset of a normal SWC than those without midazolam (p=0.03). Three patients in the CPB group and two in the non-CPB group showed continuous low voltage or flat trace after administration of fentanyl. These changes did not correlate with neurodevelopmental outcome. Sedation with midazolam has a transient effect on the background activity, whereas fentanyl can induce a severe pathologic background pattern. The significance of these changes on outcome is not yet clear. Thus, more attention should be paid to these effects when interpreting aEEG in this population.

Effects of precurarisation on suxamethonium-induced postoperative myalgia during the first trimester of pregnancy

Two hundred and fifty women undergoing termination of pregnancy during the first trimester under general anaesthesia were studied to determine the effects of precurarisation on suxamethonium-induced postoperative myalgia and on the need for postoperative analgesics after suxamethonium. Either alcuronium (0.03 mg/kg), atracurium (0.04 mg/kg), tubocurarine (0.05 mg/kg), vecuronium (0.01 mg/kg) or saline was administered in a double-blind manner 4 min before giving suxamethonium. An additional 50 patients were studied who received isoflurane rather than precurarisation and suxamethonium. Every pretreatment prevented fasciculations better than did saline (P less than 0.001). In the saline group, 92% of patients had fasciculations and in the other groups this ranged from 8 to 32%, respectively. On the first postoperative day, 76% of the patients in the saline group had myalgia while myalgia was manifested in 28, 54 and 34% of patients given alcuronium, tubocurarine or vecuronium, respectively (P less than 0.05). Atracurium failed in this effect with 62% having myalgia. In the isoflurane group, none of the patients complained of myalgia on the first postoperative morning. The need for analgesics was less (P less than 0.005) in the isoflurane group (8%) and in the pretreatment groups (18-27%) than in the saline group (42%). It is concluded that precurarisation with tubocurarine, vecuronium or, most effectively, with alcuronium but not with atracurium decreases suxamethonium-induced postoperative myalgia and seems to be necessary also during the first trimester of pregnancy.