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CHAPTER 15: Long-Term Outcomes After Critical Illness 105

Although there is some heterogeneity across different study samples comorbidities may not regain their precritical illness functional status
of ARDS patients, there appears to be less variability in reported nor premorbid HRQoL 5 years after ICU discharge. Physical disability,
HRQoL in this group compared with general populations of critically ill including ICUAW, and decrements in neuropsychological performance
patients. The following is a brief, historical overview of the emergence may contribute to this persistent dysfunction captured as a reduction in
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of the ARDS HRQoL outcomes literature that served as the sole model the physical component score (PCS) of the SF-36. This was reported as
for outcomes after critical illness until more recently. In 1994, McHugh one standard deviation below an age- and sex-matched control popula-
and her colleagues prospectively evaluated pulmonary function and tion at 5 years after ICU discharge (Fig. 15-1A). These morbidities gen-
quality of life to assess the relationship between pulmonary dysfunction erated additional health care costs that were higher than predicted for
and functional disability. These authors found that the Sickness Impact this age group and more comparable to individuals with chronic disease.
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Profile (generic quality-of-life measure of the subject’s self-perceived As discussed above, quality of life may improve over months to
physical and psychological condition) scores were very low at extuba- years after ICU discharge but, on average, does not appear to return
tion, rose substantially in the first 3 months and then exhibited only to premorbid baseline based on long-term data in ARDS patients. A
slight improvement to 1 year. When quality of life was assessed using recent meta-analysis of HRQoL studies in ARDS patients found lower
a lung-related Sickness Impact Profile score, only a modest proportion quality-of-life scores for ARDS survivors consistent with what has
of the patients’ overall disability was attributed to pulmonary dysfunc- been reported previously. In addition, HRQoL recovery in ARDS
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tion. Weinert and coworkers also identified functional impairment in survivors was uneven across domains and time, similar to the finding
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their lung injury survivors and captured disability through the Medical of Hopkins et al. Despite early improvement in the mental health
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Outcomes Study 36-item short-form health survey (SF-36), which yields domains, quality of life in ARDS survivors remains significantly
scores in eight domains including physical and social functioning, role lower than healthy populations years after ICU discharge. Another
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limitations because of emotional or physical problems, mental health, meta-analysis of quality-of-life studies in general critically ill patients
vitality, bodily pain, and general health perceptions. While all domains consistently reported lower scores than matched, normative controls
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of the SF-36 were substantially reduced in their study sample, the largest at all time points (from hospital discharge to 66 months later) after
decrements occurred in role-physical and physical functioning and were ICU discharge. Further, they found larger decrements in the four
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largely attributed to global and generalized disability. Schelling et al physical domains (physical functioning, role-physical, bodily pain, and
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made similar observations about impaired physical functioning and general health perceptions) compared to the mental domains (vitality,
inferred that disability was due to pulmonary dysfunction; however, social functioning, role- emotional, and mental health). The greatest
they did not assess this directly in their study. Davidson and colleagues gains occur in physical functioning, social functioning, and role-phys-
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assessed differences in HRQoL in ARDS survivors and comparably ill ical in the first 6 months, with only modest additional improvements
controls using the SF-36 and a pulmonary disease–specific measure thereafter. Recent 5-year ARDS data show that there is little change in
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(St George’s Respiratory Questionnaire [SGRQ]), to determine the mental domains over years, but there continues to be some improvement
degree to which perceived physical disability in ARDS survivors was in physical domains over time; however, these never achieve normal
related to pulmonary dysfunction. Similar to previous reports, all predicted values. The most persistently affected domains over time are
domains of the SF-36 were reduced and the largest decrement was in the those of general health and vitality and these do not improve between 1
role-physical domain. ARDS survivors had significantly worse scores and 5 years after ICU discharge. 2
on the SGRQ compared to critically ill controls, suggesting an ARDS- Iwashyna and colleagues found persistent reduction in functional
specific degree of physical disability but it was not clear whether this was status after sepsis and critical illness. In their older patient study sample
solely related to pulmonary dysfunction or whether there were other (median age 77), they observed a high rate of new functional limita-
important extrapulmonary contributors. tions in those who had no limits prior to their episode of sepsis (mean
Angus and colleagues used the quality of well-being score (QWB) 1.57 new limitations; 95% CI 0.99-2.15). In those with reductions in
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in a prospective cohort of ARDS survivors to measure quality-adjusted activities of daily living prior to sepsis, they noted an important further
survival in the first year after hospital discharge. The mean QWB scores decrement in function. They reported that neurocognitive and physical
for their ARDS cohort at 6 and 12 months were significantly lower than decline persisted for at least 8 years after the episode of sepsis and this
a control population of patients with cystic fibrosis. When QWB was represented an important and pivotal decline in the patients’ ability to
disaggregated into its component subscores, the symptom component live independently. 5
scores of the QWB accounted for 70% of the decrement in perfect The robust theme of acquired and persistent morbidity after critical
health at 6 and 12 months and the most common complaints were illness was also noted in a publication by Unroe and colleagues. These
4
musculoskeletal and constitutional. In their prospective cohort study of authors evaluated outcomes, care trajectories, and health care utilization
78 ARDS survivors, Orme and colleagues evaluated HRQoL and pul- in a study sample (n = 126) requiring prolonged mechanical ventilation
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monary function outcomes in patients treated with higher tidal volume (median age 55). Most patients had two comorbid illnesses at the time
versus lower tidal volume ventilation strategies. Both groups (higher and of hospitalization and the majority were not employed or were retired
lower tidal volumes) reported decreased HRQoL in physical function- or disabled. At 1 year, only 11 patients (9% of the cohort) were alive and
ing, physical ability to maintain their roles (role-physical), bodily pain, functionally independent. Risk factors for poor outcome included the
general health, and vitality (energy) on the SF-36. The minor pulmonary following: older age, greater burden of comorbid illness, and discharge
function abnormalities correlated with decreased HRQoL for domains disposition to a postacute care facility. The total cost for this cohort of
reflecting physical function. 126 patients was $38.1 million. The mean cost per patient was $306,135
(SD, $285,467) for an estimated $3.5 million per independently func-
tioning survivor at 1 year. 4
LONG-TERM FUNCTIONAL DISABILITY
The observation of impaired physical functioning after critical illness is HRQoL AND NEUROPSYCHOLOGICAL MORBIDITIES
robust across studies and investigators and persists for long periods of
time following ICU or hospital discharge and in some cases, may be irre- The landmark paper by Hopkins and colleagues first described neuro-
versible. The Davidson paper discussed above reported outcomes at cognitive dysfunction in ARDS survivors and its important impact on
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23 months after discharge and Herridge and colleagues have documented HRQoL. Fifty-five consecutive ARDS survivors had decreased HRQoL
9
persistent physical dysfunction at 2 and again at 5 years after ICU dis- related to neurocognitive disability and this was noted to persist to
charge This recent 5-year ARDS outcomes paper demonstrates that 2 years after hospital discharge. These observations were confirmed
2,27
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relatively young (median age 45), previously working patients with few by Rothenhausler and colleagues who reported that ARDS survivors

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