Mild and moderate renal dysfunction: impact on short-term outcome

Area of Science:

• Nephrology
• Cardiology
• Critical Care Medicine

Background:

• Preoperative renal dysfunction is a significant risk factor in cardiac surgery.
• The impact of creatinine clearance (ClCr) on postoperative outcomes requires further investigation.
• Understanding these associations can optimize patient management and resource allocation.

Purpose of the Study:

• To analyze the association between preoperative creatinine clearance (ClCr) and mechanical ventilation time and ICU length of stay.
• To determine if ClCr is an independent predictor of these outcomes, beyond established risk factors.
• To evaluate the clinical significance of mild renal dysfunction in the context of open-heart surgery.

Main Methods:

• A prospective study of 156 consecutive patients undergoing open-heart surgery.
• Creatinine clearance (ClCr) was calculated using the Cockcroft and Gault formula.
• Patients were divided into two groups based on ClCr: <70 ml/min (Group A) and >70 ml/min (Group B).

Main Results:

• Multivariate analysis identified ClCr <70 ml/min, hypertension, and COPD as significant predictors of ICU length of stay.
• Group A patients experienced a median ICU stay of 48 hours compared to 24 hours in Group B (p=0.0001).
• ClCr <70 ml/min and EuroScore were independently associated with increased mechanical ventilation time (VAM), with Group A patients requiring a median of 8 hours versus 6 hours for Group B (p=0.001).

Conclusions:

• Preoperative mild renal dysfunction (ClCr <70 ml/min) is an independent predictor of prolonged ICU length of stay.
• Mild renal dysfunction also independently predicts longer mechanical ventilation times following cardiac surgery.
• These findings highlight the importance of assessing renal function preoperatively to anticipate and manage postoperative outcomes.