Comparison of predicted with measured creatinine clearance in cardiac surgical patients.
OBJECTIVE
To determine whether creatinine clearance can be determined from a single plasma creatinine measurement in patients up to 5 days after cardiac surgery.


METHODS
Observational longitudinal study.


METHODS
Cardiac intensive care unit in a tertiary referral center for cardiothoracic surgery.


METHODS
Seventy-five patients (54 men, 21 women) scheduled for elective coronary artery surgery (93 postoperative patient days).


METHODS
Creatinine clearance measurement using a 4-hour urine collection and a single arterial blood sample.


RESULTS
There was significant agreement (Deming analysis r = 0.63-0.84, correlation r = 0.76-0.95, p < 0.05) between the predicted creatinine clearance and the measured creatinine clearance on each of the postoperative days. This was maintained even if the patients required inotrope or vasoconstrictor therapy, were receiving parenteral nutrition, or had changing renal function (Deming analysis r = 0.67-0.7; correlation r = 0.8-0.93, p < 0.001) but does not apply to patients with preexisting renal dysfunction (Deming analysis r = 0.36; correlation r = 0.57, p = 0.002).


CONCLUSIONS
In cardiac surgical patients with normal preoperative renal function, predicted creatinine clearance is as reliable as measured creatinine clearance up to the fifth postoperative day.
Bloor
G K
GK
Department of Anesthesia, Leeds General Infirmary, UK.
Welsh
K R
KR
Goodall
S
S
Shah
M V
MV
D006348:Cardiac Surgical Procedures; D003404:Creatinine / Q000493:pharmacokinetics*; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008657:Metabolic Clearance Rate
D003404:Creatinine