Liberation and discharge status of older patients after invasive mechanical ventilation: a retrospective cohort study

Data on the proportion of patients liberated from invasive mechanical ventilation (IMV) and the prognosis of those who have undergone IMV are limited. Objective data on prognosis are important when discussing preference for IMV. Therefore, this study explored both the proportion of liberation and prognosis after IMV in older patients in Japan.

We conducted a retrospective cohort study using claim data from April 2014 to March 2019 from the National Health Insurance, Late Elders' Health Insurance, and Long-Term Care Insurance in Tsukuba City, Japan. Patients aged ≥ 65 years who underwent IMV were included, and patients who died within 3 days after intubation were excluded. A descriptive analysis of the liberation and the discharge status on day 180 was conducted including a stratification by age categories and care level (CL) < 3 or ≥ 3. The chi-square or Fisher's exact test was conducted to assess whether liberation and discharge status differed among age categories or CLs.

In total, 272 patients were included in the study, and the median age was 78 years (interquartile range: 73-84). The median duration of mechanical ventilation was 9.0 days. Pneumonia was the most frequent main diagnosis (12.5%). In total, 73.5% achieved liberation and 42.6% were discharged alive until day 180, while 19.9% were hospitalized and 37.5% were deceased on day 180. The proportion of liberation did not differ among age categories and CLs. However, the IMV duration for those requiring CL ≥ 3 was longer, and the proportion of hospitalized patients on day 180 among patients requiring CL ≥ 3 was significantly higher than that in patients requiring CL < 3 (35.1% vs 17.4%, p = 0.012).

This study shows that many older patients can be successfully liberated from IMV. However, one third of patients died in the hospital and one fifth of patients required prolonged hospitalization. IMV and hospitalization were likely to be longer among patients requiring CL ≥ 3. Therefore, it may be important to discuss not only the potential difficulty of liberation, but also to convey the risks of undesired outcomes and physical function decline when considering IMV.