Adrenaline-induced changes in serum electrolytes, ECG, and blood pressure, with Ca-blockade pretreatment

Adrenaline infusions (AI) (0.5 micrograms adrenaline per 10 kg body weight per minute over 120 minutes) were given weekly for three weeks to 20 healthy male volunteers aged twenty-one to thirty-eight years. The AI was given after three days' treatment with diltiazem (D), verapamil (V), or placebo (PI) in a single-blind fashion. After pretreatment with Pl, serum potassium (s-K) decreased from 3.93 +/- 0.30 mmol/L (M +/- SD) to 3.33 +/- 0.31 (P less than 0.001) with the greatest change 69.75 +/- 46.24 minutes after the start of the AI. Corresponding values for s-Mg were 0.84 +/- 0.06 to 0.78 +/- 0.05 (P less than 0.01) and 106.50 +/- 36.71 minutes, for s-Ca 2.40 +/- 0.07 to 2.30 +/- 0.08 (P less than 0.01) and 103.50 +/- 36.06 minutes, for s-P 1.05 +/- 0.17 to 0.91 +/- 0.17 (P less than 0.02) and 80.25 +/- 47.25 minutes, and for s-urate 344.79 +/- 50.55 to 329.26 +/- 47.80 (P greater than 0.05) and 63.95 +/- 46.05 minutes. After pretreatment with D, AI produced similar electrolyte changes as after Pl, but the rise in blood glucose was slightly more pronounced and the drop in s-urate less pronounced. The heart rate (HR) before AI after pretreatment with D was lower than after Pl, but the increase during the AI was of the same magnitude. The AI-induced changes in systolic (SBP) and diastolic (DBP) blood pressure after D did not differ significantly from those seen after Pl, and neither did QT and QTc, whereas the PR duration was prolonged (0.18 +/- 0.03 second) when compared with Pl (0.16 +/- 0.02) (P less than 0.05). Although the magnitude of the change in DBP was not influenced, V prolonged the time till the lowest DBP (48.95 +/- 26.38 minutes) when compared with Pl (31.50 +/- 29.16 minutes) (P greater than 0.05). The other variables followed the same pattern as for D. In conclusion AI in healthy volunteers produced a drop in s-K but in addition a drop in s-Mg and s-Ca, the latter appearing later than the drop in s-K. Pretreatment with diltiazem and verapamil did not influence the magnitude of these changes but reduced the drop in s-urate.