To identify factors associated with development of pneumonia within 30 days of surgery.
Multivariate logistic regression of the American College of Surgeons’ 2007 National Surgical Quality Improvement Program (NSQIP) data. 203,836 patients of this multicenter, prospective dataset were studied.
3,561 patients (1.75%) developed postoperative pneumonia (PP). 30-day mortality was higher in patients who developed PP than those who did not (16.97% vs. 1.46%, p<0.0001). Preoperative risk factors which predict PP include ASA class (OR 1.9), bleeding disorder (OR 1.2), dyspnea (OR 1.2), emergency case (OR 1.4), esophageal varices (OR 2.0), alcoholism (OR 1.2), functional status (OR 1.6), COPD (OR 1.5), hypertension (OR 1.2), inpatient status (OR 5.9), sepsis (OR 1.3), quadriplegia (OR 1.8), rest pain (OR 1.3), male sex (OR 1.5), smoking (OR 1.5), steroid use (OR 1.3), >10% weight loss (OR 1.3) and days from admission to operation (OR 1.007). Protective factors include ventilator dependence prior to surgery (OR 0.7) and CHF (OR 0.8). Decreasing age was a lower risk factor (Age <40 vs 40–60, 40–60 vs 60, 60–80 vs >80 –all had OR 0.8). BMI of <25 was a bigger risk factor for PP than 25–40 (OR 1.2) and 40–60 (OR 1.2) but not BMI>60. BMI of 25–40, 40–60 and >60 did not have statistically significant differences. Compared to a group of surgeries with low incidence of PP (anorectal, bariatric, breast, gallbladder, appendix, adrenal, spleen, ENT/neck, obstetric/gynecologic, hernia, spine, urology and vein surgeries), higher rates of PP occurred after aortic (OR 2.6), esophageal, stomach, pancreas, duodenum, liver and bile duct (OR 4.1), intestinal (OR 2.5), brain (OR 2.9), other abdominal (OR 2.1), and thoracic surgeries (OR 3.8). There was not a higher risk with cardiac, orthopedic, skin and other vascular surgeries. All confidence intervals were significant.
PP, while uncommon, is associated with increased 30-day mortality.
Variables associated with an increased risk of PP include factors related primarily to age, gender, comorbidity, functional status, nutrition, and the type of surgery.
Himani Gupta, No Financial Disclosure Information; No Product/Research Disclosure Information