Prediction of Post Operative Complication in Patients with Valvular Heart Surgery Based on O2 Challenge Test and A-A...

Area of Science:

• Cardiology
• Pulmonology
• Critical Care Medicine

Background:

• Valvular heart disease can cause physiological lung derangements.
• Postoperative pulmonary complications (POPC) are a significant concern following valve surgery.

Purpose of the Study:

• To investigate the correlation between pre-operative O2 challenge, alveolar-arterial (A-AG) gradients, spirometry, and POPC in patients undergoing valve surgery.
• To identify pre-operative predictors of respiratory complications after cardiac valvular surgery.

Main Methods:

• 180 adult patients undergoing non-emergency cardiac valvular surgery were studied.
• Pre-operative assessments included arterial blood gas profiles (ABG) on room air and 100% O2, pulmonary function tests (PFTs), and calculation of alveolar-arterial gradients (A-AG).
• Comparison of PFTs and ABG values between patients with and without POPC.

Main Results:

• Significant differences in FEV1, FVC, FEV1/FVC%, PaO2 (on air and 100% O2), and A-AG gradients were observed between patients with and without POPC (p<0.05).
• Patients with POPC had significantly lower PaO2 values and higher A-AG gradients (A-AG100 and A-AG21).
• The A-AG100 showed an AUC of 0.59 for predicting POPC, with an optimal cut-point of 311, demonstrating 80% sensitivity and 61% negative predictive value.

Conclusions:

• Valvular heart surgery is associated with significant postoperative complications and mortality.
• Pre-operative A-AG gradients (A-AG100, A-AG21), oxygenation (PaO2100), and spirometry (FEV1/FVC) correlate with POPC.
• Routine pre-operative measurement of these parameters is recommended for patients undergoing cardiac surgery to aid in risk stratification.