Letter to the editor
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Resuscitation, 14 (1986) 255-256 Elsevier Scientific Publishers Ireland Ltd. 255 LETTER TO THE EDITOR Dear Sir, We report a patient who following an overdose of propanolol suffered a hyperkalaemic cardiac arrest during an infusion of potassium chloride. A 20-year-old 60 kg man was admitted following an overdose of 25 g of Paracetamol and 2 g of Propanolol. On arrival he was pink but had laboured respirations and was unresponsive to painful stimuli. His heart rate was 40/min and blood pressure 50 mmHg systolic. He received Atropine 2.4 mg intravenously and one unit of Haemaccel (containing 2.5 mmol of potas- sium) immediately. After intubation and a gastric lavage he was transferred to the Intensive Care Unit for artificial ventilation. Initial blood gases on 40% oxygen were: pH 7.3, PCOz 3.0 kPa, PO, 31.6 kPa, standard bicarbon- ate 13.6 mEq/l, base excess -8.7 mEq/l. The serum sodium was 144 mmol/l, potassium 3.8 mmol/l (range 3.5. 4.3 mmol/l), urea 4.5 mmol/l and sugar 9.4 mmol/l. He received a Dopamine infusion, Frusemide 40 mg intraven- ously and Pancuronium 60 mg intravenously, but no Glucagon or Suxa- methonium. His blood pressure and pulse improved and the Dopamine was discontinued after an hour. After 2 h, his urine output exceeded a litre. A potassium infusion was started to replace putative urinary potassium losses. He had received 45 mmol of potassium in 1 h, when his QRS complexes broadened and he developed asystole. With cardiac massage, intravenous calcium gluconate, intravenous dextrose and insulin, the cardiac rhythm and blood pressure were re-established. A serum potassium drawn at the time of the arrest was 10 mmol/l. He went on to make a complete recovery. This case illustrates the dangers of excessive potassium loads in Propanolol overdosage. Chronic Propanolol use leads to an increase in total body potas- sium and serum potassium (Brecht, Werner, Schoeppe, 1976; Pedersen, Pederson, Pedersen, 1979) thought to be due to impaired cellular uptake of potassium and inhibition of renin secretion (DeFronzo, Bia, Smith, 1982). The clearance of acute potassium loads in patients on beta blockers appears more controversial (Rosa, Silva, Young, Landsberg, Brown, Rowej, 1980 Smith, Kendal, Ryder, Laugher, 1984). However, severe hyperkalaemia following an overdose of Oxprenolol and potassium has previously been described (Hume and Forfar, 1977). The following factors are likely to have contributed to this patient’s hyperkalaemia: the substantial potassium load, the mild acidosis, decreased renal blood flow and glomerular filtration rate following hypotension, and reduced cellular uptake of potassium due to Propanolol. Potassium infusions should always be given for documented hypokalaemia, in modest amounts and in a controlled fashion. Additional caution is neces- sary in patients with overdoses of beta blockers. 0300-9572/86/$03,50 01986 Elsevier Scientific Publishers Ireland Ltd. Printed and Published in Ireland
Transcript of Letter to the editor
Resuscitation, 14 (1986) 255-256 Elsevier Scientific Publishers Ireland Ltd.
255
LETTER TO THE EDITOR
Dear Sir, We report a patient who following an overdose of propanolol suffered a
hyperkalaemic cardiac arrest during an infusion of potassium chloride. A 20-year-old 60 kg man was admitted following an overdose of 25 g of
Paracetamol and 2 g of Propanolol. On arrival he was pink but had laboured respirations and was unresponsive to painful stimuli. His heart rate was 40/min and blood pressure 50 mmHg systolic. He received Atropine 2.4 mg intravenously and one unit of Haemaccel (containing 2.5 mmol of potas- sium) immediately. After intubation and a gastric lavage he was transferred to the Intensive Care Unit for artificial ventilation. Initial blood gases on 40% oxygen were: pH 7.3, PCOz 3.0 kPa, PO, 31.6 kPa, standard bicarbon- ate 13.6 mEq/l, base excess -8.7 mEq/l. The serum sodium was 144 mmol/l, potassium 3.8 mmol/l (range 3.5. 4.3 mmol/l), urea 4.5 mmol/l and sugar 9.4 mmol/l. He received a Dopamine infusion, Frusemide 40 mg intraven- ously and Pancuronium 60 mg intravenously, but no Glucagon or Suxa- methonium. His blood pressure and pulse improved and the Dopamine was discontinued after an hour. After 2 h, his urine output exceeded a litre. A potassium infusion was started to replace putative urinary potassium losses. He had received 45 mmol of potassium in 1 h, when his QRS complexes broadened and he developed asystole. With cardiac massage, intravenous calcium gluconate, intravenous dextrose and insulin, the cardiac rhythm and blood pressure were re-established. A serum potassium drawn at the time of the arrest was 10 mmol/l. He went on to make a complete recovery.
This case illustrates the dangers of excessive potassium loads in Propanolol overdosage. Chronic Propanolol use leads to an increase in total body potas- sium and serum potassium (Brecht, Werner, Schoeppe, 1976; Pedersen, Pederson, Pedersen, 1979) thought to be due to impaired cellular uptake of potassium and inhibition of renin secretion (DeFronzo, Bia, Smith, 1982). The clearance of acute potassium loads in patients on beta blockers appears more controversial (Rosa, Silva, Young, Landsberg, Brown, Rowej, 1980 Smith, Kendal, Ryder, Laugher, 1984). However, severe hyperkalaemia following an overdose of Oxprenolol and potassium has previously been described (Hume and Forfar, 1977). The following factors are likely to have contributed to this patient’s hyperkalaemia: the substantial potassium load, the mild acidosis, decreased renal blood flow and glomerular filtration rate following hypotension, and reduced cellular uptake of potassium due to Propanolol.
Potassium infusions should always be given for documented hypokalaemia, in modest amounts and in a controlled fashion. Additional caution is neces- sary in patients with overdoses of beta blockers.
0300-9572/86/$03,50 01986 Elsevier Scientific Publishers Ireland Ltd. Printed and Published in Ireland
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REFERENCES
Brecht, H.M., Werner, E. and Schoeppe, W. (1976) Clin. Sci. Mol. Med., 51, Suppl. 3, 551 (S).
De Fronzo, R.A., Bia, M. and Smith, D. (1982) Clinical disorders of hyperkalaemia, Annu. Rev. Med., 33, 521-54.
Hume, L. and Forfar, J.C. (1977) Hyperkaiaemia and overdose of antihypertensive agents. Lancet, 2(8049) 1182.
Pedersen, G., Pederson, A. and Pedersen, E.B. (1979) Effect of Propranolol on total exchangeable body potassium and total exchangeable sodium in essential hyperten- sion. Stand. J. Clin. Invest., 39, 167-170.
Rosa, R.M., Silva, P., Young, J.B., Landsberg, L., Brown, R.S. and Rowej, W. (1980) Adrenergic modulation of ectrarenal potassium disposal. N. Eng. J. Med., 302,431-34.
Smith, S.R., Kendal, M.J., Ryder, C. and Laugher, R. (1984) Lack of influence of beta adrenergic blockade on serum potassium during an infusion of potassium. Eur. J. Clin. Pharmacol., 26, 425-27.
JAMES COX MARTIN STARBUCK Senior Registrar Senior House Officer Kingston General Hospital Hull Royal Infirmary Hull HU3 1 UR Hull HU3 252 U.K. U.K.
