Use of the Functional Independence Measure in People for Whom Weaning From Mechanical Ventilation Is Difficult

Background. The Functional Independence Measure (FIM) has been proposed as an outcome measure for people receiving pulmonary rehabilitation after an acute exacerbation of chronic obstructive pulmonary disease. Objective. The purpose of this study was to examine the clinical utility of the FIM after a weaning program in people for whom weaning from mechanical ventilation is difficult. Design. This was a retrospective observational study. Methods. People who had had a tracheostomy, for whom weaning from mechanical ventilation was difficult, and who were participating in a weaning program (WP group) were retrospectively evaluated. People receiving pulmonary rehabilitation after an acute exacerbation of chronic obstructive pulmonary disease (PR group) were included as a validated control group. The scores on the FIM questionnaire and the Medical Research Council dyspnea scores were assessed at admission to and at discharge from the programs. Results. Admission and discharge data from 56 participants in the WP group and 63 participants in the PR group were compared. At admission, according to the FIM, 5 participants in the WP group (7.7%) were defined as functionally independent, 34 (52.3%) were defined as partially dependent, and 26 (40.0%) were defined as completely dependent. At discharge, the mean FIM global score was significantly improved, from 47.9 (SD = 22.8) to 62.6 (SD = 30.0). For participants in the WP group, changes in the FIM score were significantly inversely related to the admission Acute Physiology and Chronic Health Evaluation (R = -.286) and Simplified Acute Physiology (R = -.293) scores and directly related to the admission FIM score (R =.355). At admission, 46 participants in the PR group (67.7%) were defined as functionally independent, 19 (27.9%) were defined as partially dependent, and 3 (4.4%) were defined as completely dependent. After pulmonary rehabilitation, the mean FIM global score was significantly improved, from 97.4 (SD = 27.5) to 102.5 (SD = 25.7). Limitations. The study was not randomized and involved a relatively small sample size. Conclusions. The FIM can be used as a functional status outcome measure in people for whom weaning from mechanical ventilation is difficult.