Fluid overload and changes in serum creatinine after cardiac surgery
Critical Care, 06/04/2012
Stein A et al. – Although both fluid overload and changes in serum creatinine are prognostic markers after cardiac surgery, it seems that progressive fluid overload may be an earlier and more sensitive marker of renal dysfunction affecting heart function and, as such, it would allow earlier intervention and more effective control in post cardiac surgery patients.Methods
- Patients submitted to heart surgery were prospectively enrolled in this study from September/2010 through August/2011.
- Clinical and laboratory data were collected from each patient at preoperative and trans-operative moments and fluid overload and creatinine levels were recorded daily after cardiac surgery during Intensive Care Unit (ICU) stay.
- Fluid overload was calculated according to the following formula: (Sum of daily fluid received (L)-total amount of fluid eliminated (L) /preoperative weight (kg)x100).
- Preoperative demographic and risk indicators, intra-operative parameters and postoperative information were obtained from medical records.
- Patients were monitored from surgery until death or discharge from the ICU.
- The authors also evaluated the survival status at discharge from the ICU and the length of ICU stay (days) of each patient.
- 502 patients were enrolled in this study.
- Both fluid overload and changes in serum creatinine correlated with mortality (OR 1.59; IC: 95% 1.18 to 2.14 p=0.002 and OR 2.91; IC:95% 1.92 to 4.40, p<0.001 respectively).
- Fluid overload played a more important role in the length of intensive care stay than changes in serum creatinine.
- Fluid overload (%): b coefficient=0.17; beta coefficient=0.55, p<0.001); change creatinine (mg/dL): b coefficient=0.01; beta coefficient=0.11, p=0.003).