Effects of salbutamol and hyperventilation on the rise in serum potassium after succinylcholine administration.

It is known that circulating catecholamines stimulating beta 2-receptors and the acid-base balance play important roles in the regulation of serum potassium (K+). The present study was undertaken to investigate the effect of salbutamol (SB), a highly selective beta 2 agonist, and hyperventilation (HV)-induced alkalosis on the change in serum K+ after succinylcholine (SCh) administration in dogs. Pretreatment with SB (0.4 microgram.kg-1.min-1 for 30 min) produced sustained decreases in serum K+ and mean arterial pressure, and transient increases in cardiac output and serum insulin concentration. Maintaining respiratory alkalosis with HV (PaCO2 = 2.6-3.3 kPa) produced sustained decreases in serum K+ and cardiac output. Although both pretreatment with SB and HV-induced alkalosis significantly reduced the absolute increases in serum K+ after SCh, the effect of SB was more remarkable than that of HV. These results suggest that the degree of beta 2-receptor activity can strongly modulate the change in serum K+ after SCh administration.