Study identifies post-extubation pneumonia as a distinct condition after surgery and key risk factors

A Hiroshima University study of more than 31,000 patients found that pneumonia occurred more often after breathing tubes were removed than during ventilation, with most cases developing within a 1–2 week window after surgery. The findings suggest this underrecognized condition may be a distinct clinical entity linked to swallowing dysfunction—and that early assessment and intervention, including identification of high-risk patients, may be key to prevention and improved outcomes.

Pneumonia that develops after removal of an endotracheal tube can significantly affect recovery and quality of life. While mechanical ventilation to support breathing is a common and life-saving procedure in both emergency and elective surgeries under general anesthesia, some patients experience difficulty swallowing after extubation. This can lead to aspiration—when food or liquids enter the airway—resulting in pneumonia that may require antibiotic treatment.

In the study, conducted at Hiroshima University Hospital in Hiroshima, Japan, assistant head nurse Junko Hirayama, lecturer Masahiro Nakamori of the Graduate School of Biomedical and Health Sciences, and colleagues examined the incidence of post-extubation pneumonia (PEP) in non-emergency surgeries, identified high-risk patient characteristics, and compared PEP with ventilator-associated pneumonia (VAP), which develops during mechanical ventilation.

Analyzing records between 2016 and 2023, the team found that 212 patients (0.67%) developed pneumonia after breathing tube removal, compared with 27 cases of VAP. The researchers identified PEP as a distinct clinical entity rather than a routine postoperative complication. The paper was published on March 16 in Scientific Reports.

Age, sex, and BMI are risk factors

Patients who developed PEP tended to be older than those who did not. Men had a 65% higher risk than women, while patients with a low body mass index (BMI <18.5) or impaired consciousness were also at significantly higher risk.

The likelihood of pneumonia was elevated across a wide range of procedures—not only head and neck surgery, but also gastrointestinal, respiratory, cardiovascular, and orthopedic operations—suggesting PEP risk should be recognized across all types of surgery.

Potential for prevention

The study highlights the impact of PEP on postoperative recovery and quality of life.

“Of particular concern was that these patients were originally admitted with the expectation of improvement through surgery, yet their health status worsened due to complications,” said Hirayama.

Nakamori emphasized that PEP may be preventable.

“We believe that early assessment and intervention focusing on swallowing function by a multidisciplinary team—including physicians, dentists, nurses, pharmacists, dietitians, dental hygienists, and rehabilitation professionals—are essential for improving clinical outcomes,” he stated.

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About Hiroshima University

Since its foundation in 1949, Hiroshima University has striven to become one of the most prominent and comprehensive universities in Japan for the promotion and development of scholarship and education. Consisting of 12 schools for undergraduate level and 5 graduate schools, ranging from natural sciences to humanities and social sciences, the university has grown into one of the most distinguished comprehensive research universities in Japan. English website: https://www.hiroshima-u.ac.jp/en