Abstract
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.
Chronic respiratory diseases are associated with symptoms such as dyspnea, fatigue, and reduced exercise capacity, which can lead to a reduced ability to perform the activities of daily living and poor health-related quality of life. Pulmonary rehabilitation programs are widely recognized and accepted as an integral part of comprehensive treatment as well as maintenance of health status for people who have chronic obstructive pulmonary disease (COPD) and are severely disabled. There is less evidence supporting the use of pulmonary rehabilitation programs for people who have other chronic respiratory diseases, are symptomatic, or continue to demonstrate reduced function despite standard medical treatment.1–3
A growing body of literature has indicated that people who have survived severe critical illnesses commonly have significant and prolonged neuromuscular complications that impair their physical function and quality of life after hospital discharge.4 Early mobilization and physical therapy represent a relatively new approach for people who are critically ill5 and are useful in weaning programs for people for whom weaning from mechanical ventilation is difficult.6
Several tools have been proposed as outcome measures for health status; each reflects an aspect of the impact of disease on people's ability to perform activities of daily living and on their well-being.7 Generic questionnaires, such as the Medical Outcomes Study 36-Item Short-Form Health Survey questionnaire and the Nottingham Health Profile, or disease-specific questionnaires, such as the Chronic Respiratory Questionnaire, the St. George's Respiratory Questionnaire, and the Maugeri Foundation Respiratory Failure Questionnaire, have been used to evaluate health-related quality of life in people with severe illnesses, including those receiving prolonged mechanical ventilation.8 Functional status questionnaires address this issue in more detail than other instruments. The Functional Independence Measure (FIM), an internationally validated tool for evaluating levels of neuromotor disability and for tallying levels of everyday self-sufficiency,9 has been used almost exclusively during neuromotor rehabilitation in people with cerebrovascular pathologies such as stroke or to study functional autonomy in people who are more than 80 years of age.10–13 Recently, it was proposed that the FIM also may be a useful outcome measure in people participating in pulmonary rehabilitation programs after an acute exacerbation of COPD14 and in people undergoing endotracheal intubation and receiving mechanical ventilation in intensive care units (ICUs).15
The purpose of this study was to examine the clinical utility of the FIM in people other than those included in previous studies.14,15 Specifically, we evaluated whether a weaning program led to improvements in FIM scores in people for whom weaning from mechanical ventilation was difficult (WP group). People participating in a pulmonary rehabilitation program after an acute exacerbation of COPD or episodes of acute respiratory failure due to other respiratory diseases were evaluated as a validated control group (PR group).
Method
Participants and Location
Data for this retrospective study were obtained from patients admitted to the Pulmonary Rehabilitation and Weaning Unit, Auxilium Vitae, Volterra, Italy, a referral rehabilitation and long-term weaning center for a large geographic area in central Italy (Tuscany); the activity of this center was recently described elsewhere.6 Patients who had had a tracheostomy, for whom weaning from mechanical ventilation was difficult, and who were consecutively (from June 2008 to May 2009) referred to the Pulmonary Rehabilitation and Weaning Unit from ICUs at other hospitals were evaluated for participation in a program of progressive discontinuation from mechanical ventilation or for discharge to a home program of long-term ventilatory assistance if weaning from the ventilator failed (WP group).6 Patients for whom weaning from mechanical ventilation was difficult were defined as those requiring more than 7 days of weaning after the first spontaneous breathing trial.16 People who were consecutively (from April to September 2009) referred for pulmonary rehabilitation programs after an acute exacerbation of COPD or episodes of acute respiratory failure due to other respiratory diseases were evaluated as a validated control group (PR group).14 All participants gave informed consent for the use of their data for research purposes.
The demographic and clinical characteristics and the main diagnoses for participants in the 2 groups are shown in Table 1. As expected, participants in the WP group had more severe illnesses. Eighty-eight participants in the WP group and 80 participants in the PR group were admitted during the study periods. Because of incomplete medical records at admission, 23 participants in the WP group and 12 participants in the PR group were not included in the study. Thirty-one (47.7%) of the 65 participants in the WP group for whom admission records were complete were weaned from mechanical ventilation, 17 participants (26.2%) remained partially dependent on the ventilator, and 8 participants (12.3%) remained completely dependent on the ventilator. During the study periods, 5 participants in the WP group died, and 4 participants in the WP group and 5 participants in the PR group were referred to acute care hospitals because of acute complications. Therefore, comparisons of discharge and admission data could be made for 56 of 88 participants in the WP group and 63 of 80 participants in the PR group.
Weaning Program
At the Pulmonary Rehabilitation and Weaning Unit, weaning protocols consisting of either progressively decreasing levels of pressure-support ventilation or progressively longer spontaneous breathing trials were provided to participants in the WP group.6,17,18 Physical therapy consisting of progressive passive and active mobilization and cough maneuvers was also provided. Participants received respiratory physical therapy adjusted to their individual needs and a session of standardized mobilization of the upper and lower extremities 6 days per week. The intensity of the exercises was increased according to the participant's capacity. Ambulation was started when considered appropriate by the medical staff. In addition, participants performed cycling exercises for the legs, arms, or both using a bedside cycle ergometer.5,19 Removal of cannulas was performed on an individual clinical basis without any specific protocol.6,20
Pulmonary Rehabilitation Program
People in the PR group participated in a multidisciplinary, 15- to 21-day, in-hospital pulmonary rehabilitation program that included the optimization of drug therapy and daily sessions of the following: supervised incremental exercises on a treadmill, a cycle, or an arm ergometer according to the protocol suggested by Maltais et al21 until the achievement of 30 minutes of continuous exercise at an intensity that elicited dyspnea at level 5 on a modified Borg scale22; abdominal, upper-limb, and lower-limb muscle activities involving lifting of progressively increasing light weight and shoulder and full-arm circling; education for participants and family members; and nutritional programs and psychosocial counseling, when appropriate. A multidisciplinary team of chest physicians, nurses, physical therapists, a dietician, and a psychologist offered care.23
Measurements
Clinical data.
The following data were recorded at admission: the Acute Physiology and Chronic Health Evaluation (APACHE II) score24; the Simplified Acute Physiology Score (SAPS II)25; chronic comorbidities, as determined with the validated Charlson Index adjusted for age26; and previous hospital length of stay.
Dyspnea.
An Italian version of the Medical Research Council dyspnea score was used to assess chronic exertion dyspnea.27
FIM.
The FIM contains 18 items. Thirteen items constitute the motor subscale, and the remaining 5 items form the cognitive subscale. All items are scored on a 7-point ordinal scale that is based on the amount of assistance required for a person to perform each activity. Higher scores on the FIM denote a higher level of independence and the need for less assistance. The sum of all 18 items represents the global score, which ranges from 18 to 126.28 At admission and at discharge, a certified physical therapist assigned a FIM score to each participant on the basis of an assessment of the following items: self-care (nutrition, hygiene, and dressing), sphincter control, mobility (transfer to bed, chair, and toilet), locomotion (walking and climbing stairs), communication (comprehension and expression), and cognitive function (social relations, problem solving, and memory).28,29 Each item was given a rating for 7 levels, where 1 or 2 points constituted complete dependence, 3 to 5 points constituted partial dependence, and 6 or 7 points constituted independence. Scores of 1 to 5 indicated the need for assistance from health care professionals such as aides, nurses, and physical therapists or respiratory therapists.
Data Analysis
Data are presented as means (standard deviations). Analyses were performed with the SPSS statistical software package, version 10.1.* Continuous variables were compared by use of a 2-tailed Student t test for paired samples to evaluate the statistical significance of changes after treatment within each group. Categorical data were compared by use of a chi-square test with the Yates correction. Correlations were assessed with the Spearman coefficient. A P value of less than .05 was considered statistically significant.
Results
Clinical Outcomes
Dyspnea.
The programs resulted in significant improvements in dyspnea in both groups (Tab. 2).
Functional status.
Table 2 shows mean changes in the FIM global score and subscale scores for both groups. Figure 1 shows the individual changes in the FIM global score. According to the FIM score at admission, 5 (7.7%), 34 (52.3%), and 26 (40.0%) of the 65 participants in the WP group were defined as functionally independent, partially dependent, and completely dependent, respectively. After the program, 13 (50.0%) of the 26 participants who were completely dependent at admission moved to partial dependence, and 11 (32.4%) of the 34 participants who were partially dependent moved to independence. At admission, 46 (67.7%), 19 (27.9%), and 3 (4.4%) of the 68 participants in the PR group were defined as functionally independent, partially dependent, and completely dependent, respectively. After the program, 1 participant moved from complete to partial dependence, and 7 participants (36.8%) moved from partial dependence to functional independence.
Individual and mean Functional Independence Measure (FIM) global scores at admission and at discharge in people receiving pulmonary rehabilitation after an acute exacerbation of chronic obstructive pulmonary disease (PR group) and in people who had had a tracheostomy, for whom weaning from mechanical ventilation was difficult, and who were participating in a weaning program (WP group). Light gray, white, and dark gray shading indicates functionally complete dependence, partial dependence, and independence, respectively. Individual values and changes are shown as small black squares and thin lines. Mean group values and changes are shown as thick blue bars and thick lines. The statistical significance of mean FIM score changes is indicated for both groups. P values were determined with a t test for paired samples: *P<.05; **P<.01.
In the WP group, changes in the FIM scores were significantly inversely related to the admission APACHE II score (R=−.286, P=.033) and SAPS II (R=−.293, P=.029) and directly related to the admission FIM score (R=.355, P=.007). In the PR group, changes in the FIM scores were inversely correlated with the admission FIM score (R=−.619, P=.000) but were significantly related to hospital length of stay before admission (R=.258, P=.045), to the Charlson Index (R=.276, P=.046), and to the admission APACHE II score (R=.321, P=.012).
As shown in Figure 2, all FIM subscale scores were significantly improved in participants in the WP group (P<.01). Participants in the PR group showed improvements in the FIM global score (P<.05) and the FIM subscale scores for self-care (P<.01) and communication, mobility, and locomotion (P<.05) but not cognitive function or sphincter control.
Admission and discharge mean Functional Independence Measure (FIM) subscale scores in people receiving pulmonary rehabilitation after an acute exacerbation of chronic obstructive pulmonary disease (PR group) and in people who had had a tracheostomy, for whom weaning from mechanical ventilation was difficult, and who were participating in a weaning program (WP group). Values are ratios of maximum subscale scores. The statistical significance of changes is indicated. P values were determined with a t test for paired samples: *P<.05; **P<.01; NS=not significant.
After the weaning program, 80% of the participants defined as independent according to FIM categories were discharged to home, whereas 33.3% and 14.3% of participants defined as partially dependent and completely dependent, respectively, were discharged to home.
Discussion
Functional status and health-related quality of life are important expectations of patients receiving prolonged mechanical ventilation and their surrogates.30 The present study shows that the level of neuromotor disability in people for whom weaning is difficult improves in response to an appropriate weaning program, indicating that the FIM may be a useful outcome measure of functional status for this population. The results of the present study also confirm and extend to people with more severe illnesses the results obtained by Pasqua et al14; they reported that inpatient pulmonary rehabilitation carried out over 4 weeks was effective in improving the level of neuromotor disability in a small group of patients with COPD and respiratory failure, as assessed with the FIM, in a manner similar to that used for dyspnea, exercise capacity, and health-related quality of life. Furthermore, the results of the present study are the first to extend to people for whom weaning is difficult the results of Lieberman et al.15 In a prospective observational, noninterventional study of 641 older patients in medical wards and ICUs, they used the FIM before hospitalization, at discharge from the hospital, and 1 year later. In that study, only 11% of all older patients receiving ventilation had FIM scores of greater than or equal to 90 (index of good performance) 1 year after the hospitalization.
Studies of functional status in patients who have survived on prolonged ventilatory support have had conflicting results. Patients who have COPD, who have survived acute or chronic respiratory failure, and who require mechanical ventilation have poorer perceived health status and cognitive function than patients who have stable COPD, who have received long-term oxygen therapy, but who have had no previous ICU admission.31 Some studies have demonstrated minimal impairments in both the short term and the long term,32,33 whereas others have shown significant reductions in health status.34 The importance of evaluating the health status of patients in critical condition is supported by a recent study by Lieberman et al35 of 579 patients who received mechanical ventilation in ICUs and outside ICUs. They reported that despite the ethical problems related to this issue, in practice the triage staff considered more advanced age and poor functional status, as assessed with the FIM, as negative factors in the decision to hospitalize a patient in an ICU.
Substantial improvements in domestic activity and function after pulmonary rehabilitation for COPD have been reported.36 Although the issue was beyond the objective of the present study, our results confirm the positive effects of weaning programs17 and early physical therapy37,38 on functional status in people for whom weaning from mechanical ventilation is difficult.39–41
The FIM is a good indicator of a patient's need for assistance13; nevertheless, it does not measure the psychological, communication, and social recognition impacts of the disability, quality of life, and patient satisfaction. Therefore, specific tools for measuring health-related quality of life should be used together with the FIM to provide a thorough evaluation of patients. It was reported that FIM scores and health-related quality of life improved similarly in patients with COPD.14
Limitations
The present study had some limitations. No specific measure of health-related quality of life was used. The APACHE II score and the SAPS II were not measured at discharge. The study was not randomized, this initial experience involved a relatively small sample size, and the available information regarding premorbid functional status was limited. Finally, the present study was conducted in Tuscany, and the results may not be representative of those in other countries. Nevertheless, the clinical results obtained with our long-term weaning model described elsewhere6 and confirmed in the present study suggest the opportunity for research with original and specific models based on local needs and health care organizations.42
Conclusion
The FIM may be a useful outcome measure of functional status in people with respiratory failure. Like dyspnea, the level of neuromotor disability is improved in people for whom weaning from mechanical ventilation is difficult in response to appropriate weaning programs including early mobilization and physical therapy. Our findings warrant future prospective, randomized studies of pulmonary rehabilitation with FIM as an outcome measure.
Footnotes
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Ms Montagnani and Dr Ambrosino provided concept/idea/research design. Dr Ambrosino provided writing and project management. Ms Montagnani, Dr Vagheggini, Dr Panait Vlad, Mr Berrighi, and Mr Pantani provided data collection and participants. Ms Montagnani, Dr Vagheggini, and Dr Panait Vlad provided data analysis. Dr Vagheggini, Mr Berrighi, and Mr Pantani provided facilities/equipment.
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↵* SPSS Inc, 233 S Wacker Dr, Chicago, IL 60606.
- Received November 2, 2010.
- Accepted February 23, 2011.
- © 2011 American Physical Therapy Association
References
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