Postoperative aspiration pneumonia is a feared complication
contributing significantly to postoperative morbidity and mortality.
Over decades, there has been little progress in reducing incidence
and mortality of postoperative aspiration pneumonia. Here, we
assessed risk factors for postoperative aspiration pneumonia in
general and abdominal surgery patients.
Patients undergoing surgery between January 2012 and December 2018
were included in this exact matched and weighted case-control study.
Data from a prospectively acquired clinical database were
Among 23,647 patients undergoing 32,901 operations, 144 (0.44%, 95%
Confidence Interval: 0.37%-0.52%) cases of postoperative aspiration
pneumonia were identified. Ninety-day mortality was 27.8% (n =
40). Major risk factors for postoperative aspiration pneumonia were
emergency surgery in patients with prolonged preoperative fasting
(>6 hours; odds ratio: 3.25, 95% confidence interval: 1.46-7.26;
P < .001), older age with increasing risk in octogenarians
compared to seniors (65-80 years: n = 69; odds ratio 5.23, 95%
confidence interval: 2.18-12.51; >80 years: n = 50; odds
ratio 13.72, 95% confidence interval: 4.94-38.09; P < .001),
American Society of Anesthesiologists scores >II (American
Society of Anesthesiologists III: n = 90; odds ratio 3.38, 95%
confidence interval: 1.08-16.01; American Society of
Anesthesiologists IV/V: n = 18; odds ratio 5.20, 95% confidence
interval: 1.48-27.61; P < .001), and body mass index <18 kg/m
(n = 9; odds ratio: 2.53; 95% confidence interval: 1.04-6.11;
P = .029). Laparoscopies (odds ratio 0.45, 95% confidence
interval: 0.23-0.88; <0.001) and female sex were associated with
a decreased risk for postoperative aspiration pneumonia (odds ratio
0.40, 95% confidence interval: 0.23-0.69; P < .001).
Preventive measures to reduce postoperative aspiration pneumonia
should focus on older patients with American Society of
Anesthesiologists scores ≥III undergoing open surgery. Cachectic
patients and patients undergoing emergency surgery with prolonged
preoperative fasting require increased attention. Laparoscopy was
associated with a lower risk for postoperative aspiration pneumonia
and should be preferred whenever appropriate.