Intermittent intravenous potassium therapy in cardiopulmonary bypass patients
Manning, S.H.; Angaran, D.M.; Arom, K.V.; Lindsay, W.G.; Northrup, W.F.; Nicoloff, D.M.
Clinical Pharmacy 1(3): 234-238
1982
ISSN/ISBN: 0278-2677 PMID: 7185519 Document Number: 197018
Cardiopulmonary bypass patients were studied during the first 24 h postoperatively to determine the dose response characteristics and possible influences of pH change and propranolol on serum K concentrations. Sixty patients whoe received 197 courses of i.v. K therapy were studied. KCI was administered in a maintenance solution of 20 mmol KCI in 1000 ml 5% dextrose and 0.2% NaCl injection and supplemented with 10 mmol KCL in 50 ml of the maintenance solution infused over 1 h, repeated up to 3 times to achieve a serum K concentration greater than 4 mmol/l. Urine samples were collected from 14 patients. Blood samples for serum K determinations were collected from the brachial arterial line every 6 h, at the occurrence of an arrhythmia and 15-30 min after each 33 mmol of supplemental K. The average K requirements were 129 .+-. 35 mmol/24 h. The linear correlation between dose and change in serum K was r = 0.4. Because 33 mmol/3 h represented 115 of all courses (60%), the following data are based on this amount. The mean change in serum K was 0.40 .+-. 0.45 mmol/l (-0.7-2.1), although 20 courses of therapy produced either no change or a decline in serum K. A rise in serum K of .ltoreq. 0.4 mmol/l was observed in 75 instances. Concurrent propranolol administration was accompanied by a greater rise, 0.45 .+-. 0.36 mmol vs. 0.33 .+-. 0.33 mmol/l in serum but was not significantly different. There was now difference in serum K response when analyzed for pH change. The average urine K elimination was 29.4 .+-. 10 mmol/4 h (8.9-101). An increase in serum K in which elimination exceeded intake occurred 4 times. The only adverse effect was pain at site of injection in 3 patients receiving the K supplementation by peripheral line. KCl administered by this method is apparently effective, but therapy must be monitored because of the unpredictable response.