"Self-taming" of suxamethonium and serum potassium concentration

Rapid Sequence Induction and Intubation

The modern version of RSI starts with preoxygenation. General anaesthesia is then induced using a rapid acting intravenous anaesthetic and a rapid acing muscle relaxant. Cricoid pressure is applied by an experienced assistant during induction, which should then be maintained until the trachea of the patient is intubated, correct positioning of the tracheal tube confirmed and the cuff inflated. The patient is conventionally not ventilated during this phase but critically ill patients are exceptions. The patient's tracheal should be intubated when adequately paralysed and its position verified. The assistant can then relieve the cricoid pressure and the tracheal tube fixed.

Serum potassium and sodium levels following intravenous suxamethonium in pediatric dental anesthesia

The effects of rectally administered midazolam (.35 mg/kg), diazepam (.70 mg/kg), and placebo used as preanesthetic medications on serum levels of potassium after intravenous suxamethonium in children undergoing dental extractions under halothane anesthesia were examined. Ninety patients between the ages of 2 and 7 years were randomly allocated into three groups in this double-blind parallel study. Blood samples were taken immediately after induction with halothane (Pre-S) and at 1, 3, 5, 10, and 15 minutes after administration of suxamethonium (Post-S). Serum from these samples was analyzed in duplicate for potassium and sodium and the data analyzed statistically. The results showed that mean serum potassium levels tended to remain higher in the two groups that had received a benzodiazepine than in the controls at 5, 10, and 15 minutes Post-S. Although the increases in plasma potassium differed significantly from Pre-S at the various times within each patient group, no significant intergroup differences could be shown except at the 15 minute Post-S stage, when the mean serum potassium level of the placebo group was significantly closer to its Pre-S value than that of the diazepam group. At all stages Post-S the mean serum sodium levels for each of the three groups showed statistically significant decreases from their Pre-S values. However, no statistically significant intergroup differences could be shown.

Suxamethonium and hyperkalaemia

Severe life-threatening hyperkalaemia may occur following administration of suxamethonium during certain periods after burns, neurological injuries, and in certain other conditions. Although this response is well-known, there is disagreement about when it may occur. This review describes the normal hyperkalaemic response to suxamethonium, the factors affecting it, the conditions in which it may be exaggerated, and the periods of high risk.

Myalgia and biochemical changes following intermittent suxamethonium administration. Effects of alcuronium, lignocaine, midazolam and suxamethonium pretreatments on serum myoglobin, creatinine kinase and myalgia

One hundred gynaecological patients for laparoscopy divided into five groups were studied to determine the effects of a number of pretreatments on serum myoglobin, creatinine kinase and myalgia following intermittent suxamethonium administration. One group acted as controls, while the other groups were given intravenous pretreatments of alcuronium 2 mg, midazolam 0.15 mg/kg, lignocaine 1.5 mg/kg and suxamethonium 7 mg. Serum myoglobin was determined by radio-immunoassay. The mean increases in the control group were 167 micrograms/litre myoglobin at 20 minutes and 196 IU creatinine kinase at 24 hours; 13 out of 20 patients responded with a marked increase of serum myoglobin at 20 minutes and of creatinine kinase at 24 hours. Only alcuronium pretreatment prevented myoglobin increase at 20 minutes, abolished creatinine kinase increase at 24 hours and reduced 24-hour myalgia. The other pretreatments slightly reduced myoglobin increase at 20 minutes and 24-hour creatinine kinase but did not reduce myalgia. Only one patient in the whole study had markedly elevated serum myoglobin at 24 hours. We conclude that only non-depolarising relaxant pretreatment is effective in the reduction of some of the adverse effects of suxamethonium administration.