A comparative study of different modalities used in the emergency treatment of hyperkalaemia in patients with renal failure at the Kenyatta National Hospital

Abstract

70 patients with acute renal (10 patients) and chronic renal (60 patients) failure with hyperkalaemiawere managed at the Kenyatta National Hospital (KNH) medical wards and Renal Unit between August 1995 and January 1996. The patients were divided into 7 different trearrnenr groups, each consisting of 10 patients. Treatment A group had glucose 25g i.v. with insulin10 units i.v., Treatment B group had 50 mmol 8.4% Sodium bicarbonate infusion. TreatmentC group had 0.5 mg salbutamol i. v. in 50 rnls 5% Dextrose, Treatment D group a combinationof treatments A and B, Treatment E group had a combination of treatments B and . C, Treatment F group had a combination of treatments A and C, Treatment G group had a combinationof treatments A and Band C. Serum potassium was measured, 30 minutes, 1 hour, 2 hours, 4 hours and 8 hours after treatment. Plasma glucose concentration was measured before treatment and at 1 hour after in all patients. Electrocardiography was done before treatment on all patients and repeat ECG was done 30 minutes and 1 hour after treatment for the patients with features of hyperkalaemia on the initial ECG. All the treatment modalities had satisfactory potassium lowering effect. The single treatment modalities A, Band C had a decrease in mean serum potassium at 1 hour of 1.14 + 0.66 mmollL (p < 0.001),0.57 + 0.22 mmollL (p < 0.001) and 1.03 + 0.41 mmollL (p < 0.001) respectively. Results of treatments A and C were comparable. Treatment B induced the smallest decrease in potassium at 1 hour and also at all the other time intervals. Amongst the

nearmentmodalities combinations D, E, F the decrease in mean serum potassium at 1 hour was 1.18 ± 0.50 mmollL (p < 0.00l), 0.82 + 0.40 mmollL (p < 0.001) and l.39 ± 0.66 mmollL (p < 0.001) respectively. Treatment E induced the smallest decrease in potassium at 1 hour and also at all the other time intervals of the 2 treatment modalities combinations. Treatment E induced a lower decrease in mean serum potassium at all the time intervals comparedto treatment C. Treatments D and F induced greater decreases in mean serum potassiumat all time intervals when compared to the single treatment modalities. Treatment G hadthe greatest decrease in mean serum potassium at 1 hour of L54 + 0.59 mmollL (p < 0.001) and at all the other different time intervals when compared to the other treatment modalities. Treatment A induced a significant decrease (p < 0.05) in the repeat plasma glucose concentration. 20% of the patients managed on treatment A had hypoglycaemia. Treatment B did not cause a significant decrease (p = 0.648) in the repeat plasma glucose concentration. Treatments C, E, F and G induced a significant increase (P < 0.01) in the repeat plasma glucose concentrations. Treatment D included a significant decrease (p < O.OS) in the repeat plasma glucose concentration, but no patient had hypoglycaemia. The ECG features of hyperkalaemia did not correlate well with the serum potassium levels. The main changes on the features of hyperkalaemia on ECG occurred within the first 30 minutes after treatment. Xl Insulin with glucose and salbutamol were equally efficacious in lowering serum potassium in hyperkalaemia. The effect of the 2 treatment modalities combined was synergistic and seemed [0 protect against insulin induced hypoglycaemia. Combination of all 3 treatment modalities had themost efficacious result and seemed to prevent against insulin induced hypoglycaemia as well. The combination of salburamol and sodium bicarbonate was not synergistic.