Author: Thomas Rosenthal
Although the number of adult patients requiring mechanical ventilation (MV) declined from 2005 to 2011, approximately 9% of the 1,209,185 patients who were admitted to California community hospitals with community-acquired pneumonia (CAP) required invasive MV (IMV) within 48 hours of admission. That rate has remained relatively stable over the years (8.7% in 2005 vs. 8.9% in 2011).
Surprisingly, related research revealed that patients with prolonged IMV—or those with a tracheostomy—were less likely to be aged 80 years and older, although this age group was more likely to be admitted to an ICU with CAP. Elderly patients had lower odds of both prolonged IMV (odds ratio [OR], 0.53; 95% CI, 0.49-0.56) and tracheostomy (OR, 0.42; 95% CI, 0.38-0.46) compared with patients between 18 and 34 years of age.
Both studies were presented at the 2018 annual meeting of the Society of Critical Care Medicine (abstracts 650 and 1031, respectively).
In the second study, the researchers also found underlying interstitial lung disease was the comorbidity most strongly associated with prolonged IMV (OR, 1.78; 95% CI, 1.72-1.85), and stroke was most strongly associated with tracheostomy (OR, 2.19; 95% CI, 2.03-2.36).
The researchers surmised that the results are related to treatment decisions for elderly patients as well as a trend toward a quicker response to a CAP diagnosis. For elderly patients, it could be that some treatment options are foregone because of the patient’s advanced age. “We cannot completely account for why prolonged IMV and tracheostomy are less frequently applied with advancing age,” said lead author Paul Bergl, MD, a fellow in the Division of Pulmonary, Critical Care and Sleep Medicine and an assistant professor in general internal medicine at the Medical College of Wisconsin, in Milwaukee.
Dr. Bergl said his research team suspected the systematic bias against providing IMV to older patients was because the elderly are less likely to survive prolonged IMV or find living with a tracheostomy acceptable. However, as outcomes for patients with severe CAP are improving, the question of providing prolonged IMV must include considerations of the patient and family, Dr. Bergl said.
“The finding that younger age is a risk factor for prolonged mechanical ventilation is surprising and unexpected,” said Ram Mohan Subramanian, MD, an associate professor of medicine and surgery and the medical director of liver transplantation at Emory University School of Medicine, in Atlanta, who was asked to comment. “As suggested by the authors, a potential explanation for their study’s findings is treatment limitations or systematic bias in caring for the elderly in this specific cohort of patients.
While advanced age may be affecting treatment options, education and awareness of CAP could be influencing speedy treatment. The decline in adjusted mortality and adjusted risk of requiring MV for CAP from 2005 to 2011 “may reflect improved recognition and prompt treatment of pneumonia-related sepsis and overall advances in critical care,” Dr. Bergl said.
“CAP is a frequent reason for hospital admission and the sixth most common cause of death in Western countries,” Dr. Bergl said. “About 50% of patients with CAP require ICU care.” In the elderly population, the death rate is 280 per 100,000 compared with 17 per 100,000 in the general population, he said.
“We have several reasons to believe outcomes from CAP are improving,” Dr. Bergl said. “There is general recognition that local, national and international sepsis campaigns have led to protocolized early sepsis care and have improved outcomes, which might be reflected in CAP outcomes.”
Dr. Bergl said, “There is also a growing interest and evolving landscape in the use of noninvasive positive pressure ventilation and heated humidified high-flow oxygen by nasal cannula in managing CAP patients. And finally, there is emerging evidence that corticosteroids reduce ICU utilization and mechanical ventilation in hospitalized patients with severe CAP.”