Key Point

Routine preoperative pulmonary function tests do not lead to improved outcomes in patients undergoing coronary artery bypass graft surgery.

ORLANDO—Contrary to expectations, a study by Marjan Bahador, MD, and associates showed that routine preoperative pulmonary function tests (PFTs) do not improve mortality or other major outcomes for patients who undergo coronary artery bypass graft (CABG) surgery. Before commencing the study, which Dr. Bahador presented at the Society of Critical Care Medicine annual meeting, the investigators had hypothesized that preoperative PFTs would lead to better outcomes in these patients by helping to identify those at high risk due to severe pulmonary disease.

Included in the study were 74 patients (group 1) who had nonemergent CABG surgery at Cooper University Hospital in Camden, New Jersey, during the six months before the implementation of a policy requiring preoperative PFTs for all patients having such surgery. During that time, PFTs were ordered prior to CABG surgery only when specifically indicated, noted Dr. Bahador.

The study also included 104 patients (group 2) who had nonemergent CABG surgery during the seven months after the policy was implemented. Thirty of these patients were excluded from the final analysis because their PFTs were not completed before surgery.

“There was no statistically significant difference between patients in groups 1 and 2 with regard to mortality, postoperative hospital length of stay, length of stay in the ICU, or ventilator hours,” pointed out Dr. Bahador. “Although the difference was not statistically significant, patients in group 2 with an FEV1 of less than 70% had longer hospital and ICU length of stays than their counterparts in group 1.”

These study findings complement those of prior research conducted by Jacob and colleagues, who found that preoperative PFTs were not useful in predicting CABG outcomes. That study included 193 consecutive CABG patients who had preoperative PFTs.

“Overall, pulmonary function tests had no predictive value for postoperative pulmonary and nonpulmonary complications, nor for durations of mechanical ventilation and intensive care unit stay,” reported Jacob et al. “There was a trend toward increased length of hospital stay in patients with impaired pulmonary function tests, but this was consistent with random variation.”            

—Timothy Begany

Suggested Reading
Bahador M, Rajaram S-S, Cilley J, et al. Will institution of a policy requiring routine preoperative pulmonary function tests (PFT) in patients undergoing coronary artery bypass grafting (CABG) change the postoperative outcomes? Presented at: 36th Critical Care Congress of the Society of Critical Care Medicine; February 18, 2007; Orlando, Florida.
Jacob B, Amoateng-Adjepong Y, Rasakulasuriar S, et al. Preoperative pulmonary function tests do not predict outcome after coronary artery bypass. Conn Med. 1997;61:327-332.

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