Risk factors for transient dysfunction of gas exchange after cardiac surgery

Objective

A retrospective cohort study was preformed aiming to verify the presence oftransient dysfunction of gas exchange in the postoperative period of cardiacsurgery and determine if this disorder is linked to cardiorespiratoryevents.

Methods

We included 942 consecutive patients undergoing cardiac surgery and cardiacprocedures who were referred to the Intensive Care Unit between June 2007and November 2011.

Results

Fifteen patients had acute respiratory distress syndrome (2%), 199 (27.75%)had mild transient dysfunction of gas exchange, 402 (56.1%) had moderatetransient dysfunction of gas exchange, and 39 (5.4%) had severe transientdysfunction of gas exchange. Hypertension and cardiogenic shock wereassociated with the emergence of moderate transient dysfunction of gasexchange postoperatively (P=0.02 andP=0.019, respectively) and were risk factors for thisdysfunction (P=0.0023 and P=0.0017,respectively). Diabetes mellitus was also a risk factor for transientdysfunction of gas exchange (P=0.03). Pneumonia was presentin 8.9% of cases and correlated with the presence of moderate transientdysfunction of gas exchange (P=0.001). Severe transientdysfunction of gas exchange was associated with patients who had renalreplacement therapy (P=0.0005), hemotherapy(P=0.0001), enteral nutrition(P=0.0012), or cardiac arrhythmia(P=0.0451).

Conclusion

Preoperative hypertension and cardiogenic shock were associated with theoccurrence of postoperative transient dysfunction of gas exchange. Thepreoperative risk factors included hypertension, cardiogenic shock, anddiabetes. Postoperatively, pneumonia, ventilator-associated pneumonia, renalreplacement therapy, hemotherapy, and cardiac arrhythmia were associatedwith the appearance of some degree of transient dysfunction of gas exchange,which was a risk factor for reintubation, pneumonia, ventilator-associatedpneumonia, and renal replacement therapy in the postoperative period ofcardiac surgery and cardiac procedures.