Potassium homeostasis during & after cardiopulmonary bypass.
Potassium homeostasis was studied in 30 patients undergoing cardiac surgery by employing cardiopulmonary bypass (CPB) and moderate hypothermia, and using morphine, N2O, relaxant anaesthesia. There was a trend for hypokalemia, and for maintaining a K+ level of 4-4.5 mmol/l, K+ infusion was required during CPB (9.017 mmol/m2 BSA/h). K+ infusion required in the post-operative period was considerably less (1.532 mmol/m2 BSA/h). There was no significant difference in the K+ levels of patients receiving preoperative diuretic therapy, as compared to those not receiving such therapy. Potassium requirement was significantly higher in patients under-going CABG and valvular heart disease, as compared to congenital heart disease. The mean urinary loss of K+ during bypass was found to be 2.95 mmol/m2 BSA/h, which was only 32 per cent of that required to be infused (9.017 mmol/m2 BSA/h). The mean excretion of K+ in the post operative period was significantly higher (4.53 mmol/m2 BSA/h) than K+ required to be infused during this period (1.532 mmol/m2 BSA/h).
Bhatt
S B
SB
Department of Anaesthesiology, All India Institute of Medical Sciences, New Delhi.
Jayalakshmi
T S
TS
Dash
H H
HH
Raghavan
S V
SV
Bithal
P K
PK
Kale
S C
SC
D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D006706:Homeostasis; D006801:Humans; D007008:Hypokalemia / Q000209:etiology* / Q000517:prevention & control; D011183:Postoperative Complications; D011188:Potassium / Q000008:administration & dosage / Q000378:metabolism*
D011188:Potassium