A new study finds that patients aged 65 and older who survive an episode of mechanical ventilation during a hospitalization are more likely to suffer from long-term disabilities after leaving the hospital than those who survive hospitalization without mechanical ventilation. The results, published in the American Thoracic Society’s American Journal of Respiratory and Critical Care Medicine, were borne out even though the levels of functional disability prior to hospitalization were similar in both groups.
“Our findings offer the first nationally-representative estimates of functional status outcomes for elderly patients who have survived mechanical ventilation, using a prospective population-based sample,” said Amber Barnato, MD, associate professor of medicine at the University of Pittsburgh. “Unfortunately, 70% of elders who receive mechanical ventilation will not survive the year. And the 30% who are strong enough to survive will be very disabled.”
Previous studies on the effects of mechanical ventilation on elderly patients have offered conflicting results, and were limited by their local patient sampling and lack of first-person information about physical function before the illness.
For this study, researchers used data collected over a 7-year period in the Medicare Current Beneficiary Survey (MCBS), a continuous survey of a nationally representative sample of aged, disabled, and institutionalized Medicare beneficiaries sponsored by the Centers for Medicare and Medicaid Services. MCBS conducts in-person interviews with each sampled beneficiary four times per year for four years, after which they rotate off the panel and new beneficiaries are invited to join. Questions related to health and functional status are asked every autumn.
The researchers linked beneficiaries’ survey responses from the autumn survey with their responses 1-year later. Beneficiaries who were hospitalized during the 12-month period and who survived until their next autumn interview were included and divided into two groups: those who had received mechanical ventilation during hospitalization and those who had not. The researchers reviewed more than 130,000 person-years of data, from which about 12,000 person-years of data qualified for inclusion in the study.
The patients’ pre- and post-hospitalization disability levels with regard to mobility and activities of daily living (ADL) were rated on a scale ranging from zero (not disabled) to 100 (completely disabled.
Comparing the two groups, the researchers found those who survived mechanical ventilation experiences 30% greater ADL disability (14.9 versus 11.5) and 14% greater mobility difficulty (25.4 versus 22.3) than non-ventilated counterparts.
“This is especially important because the pre-hospitalization scores of the patients who were and weren’t mechanically ventilated were similar,” said Barnato. “Being sick enough to require mechanical ventilation, and perhaps even the experience of mechanical ventilation itself, really takes the vim and vigor out of people.”
Source: American Thoracic Society