Special Feature

Life After ARDS: What Survivors Tell Us

By Karen L. Johnson PhD, RN, CCRN, Assistant Professor, School of Nursing, University of Maryland, Baltimore, is Associate Editor for Critical Care Alert.

Dr. Johnson reports no financial relationship to this field of study.

In the early 2000s, substantial evidenced-based interventions were added to the care of critically ill patients that significantly reduced mortality—including low tidal volume ventilatory support for acute respiratory distress syndrome (ARDS),1 protocolized sedation with daily awakening,2 Drotrecogin-alpha for severe sepsis,3 tight glycemic control,4 corticosteroids for refractory septic shock5 and preventative strategies for ventilator associated pneumonia.6 Research demonstrates that implementation of these interventions increases chances of survival of critical illness.

Is it enough to judge our care by survival rates? Some suggest that survival is a poor metric for describing the impact of critical illness7 and that discharge from the ICU is not necessarily the same thing as an immediate return to full health and happiness.8 Do these patients, whose lives we save, go on to live happily ever after? Unfortunately, the answer is not a resounding "Yes!". There is a growing body of research documenting the negative outcomes associated with critical illness that have become more apparent as we switch from evaluating mortality outcomes to patient-centered outcomes. Studies using patient-centered outcomes help us understand the value of our care and the outcomes of our care on a more human and social dimension.8

This review will focus on what we currently know about patient-centered outcomes of patients who survive ARDS. As survival rates improve among patients with this critical illness,1,9 there is a growing need to understand the long term effects of this condition and its treatment. Implications for practice and further research will also be discussed.

Pulmonary Outcomes

Despite the extraordinary toll the ARDS disease process takes on the lungs while patients are in the ICU, it appears that, in the long term, pulmonary structure and function escape relatively unharmed. We've known for some time that for most patients, pulmonary function is nearly normal by six months to one year after discharge.9-12 More recent studies reveal decreased carbon monoxide diffusion capacity that persists for over a year after discharge.13-16 However, most patients do not require supplemental oxygen after one year.16 Chest X-rays are normal, or have minor abnormal findings at one year.13,16 A small percentage of patients have some mild abnormalities in static and dynamic lung volumes13,14 that can persist up to five years after discharge,17 but this does not cause any significant limitations in terms of subjective complaints of shortness of breath or dyspnea.

Global Outcomes

Perhaps the most surprising results of studies evaluating long-term patient-centered outcomes in survivors of ARDS, is not only the wide range of extrapulmonary problems ARDS survivors report, but also the magnitude and duration of these problems. In a longitudinal study, Herridge and colleagues16 followed 109 survivors of ARDS at 3, 6, and 12 months post-discharge. Upon discharge from the ICU, the patients were severely wasted and had a mean weight loss of 18% of their baseline weight. But most had returned to baseline by one year. All patients reported poor function as a result of muscle weakness and fatigue. Additional global outcomes identified from this study are summarized in Table 1.

Exercise and Activity

At the time of discharge, most ARDS survivors report difficulty in performing activities of daily living (bathing, dressing, toileting, etc). Fortunately, at one year post-discharge most patients are independent in these activities.18 The distance that they can walk without extreme fatigue increases over the year, but still remains lower than predicted.15,16 While this may be due to decreased diffusion capacity, it is interesting to note that patients state their movement limitations are due to generalized muscle weakness and fatigue and not due to shortness of breath.13,14,18

Return to Work

Perhaps one of the most alarming patient-centered outcomes revealed by recent studies is the dismal return-to-work rate. Several studies report less than half of ARDS survivors return to work within one year after discharge.16,19,20 Reasons for not returning to work include persistent fatigue and weakness, poor functional status as a result of immobility of large joints and foot drop, work related stress, voluntary retirement, and job retraining.16

Cognition

In one of the first studies to evaluate cognitive function in ARDS survivors, Hopkins and colleagues assessed neuropsychological function in 55 patients over the course of a year.18 They found that all patients at time of hospital discharge had observable cognitive impairments including impaired memory, attention, concentration, and decreased speed of mental processing. Unfortunately, these impairments improved in only a small percentage of patients. At one year post-discharge, 78% of patients continued to demonstrate impaired memory, attention and concentration; 48% had decreased mental processing speed, and 30% had global cognitive decline. These patients could not remember what to buy at the grocery store, what people said to them, whether they took their medications, or when their appointments were scheduled. Furthermore, they could not follow directions, particularly if they were given two or more items to remember. Patients reported these cognitive impairments made it difficult for them to return to work.

Additional studies have made similar observations on the extent of cognitive impairment in ARDS survivors.20,21,22 In a recent follow-up study, Hopkins and colleagues found that even at two years after discharge, neurocognitive function had not improved.22 Patients found that activities that required memory, attention, or quick mental processing speed were very difficult or impossible. The investigators found no relationship among cognitive function and several variables including ICU length of stay, APACHE II score, duration of intubation, tidal volumes administered, gender, or days receiving sedatives, narcotics or paralytic medications.

Health-Related Quality of Life

The health-related quality of life, or subjective health status in various dimensions of psychosocial and physical functioning, is increasingly being used as a relevant measure of patient-centered outcome of ICU care.23 Studies have used a variety of instruments to evaluate health-related quality of life, and there is considerable debate as to the most appropriate instrument choice in ARDS survivors.

Several studies have assessed health-related quality of life in ARDS survivors.14,17,20,24,25 All studies indicate that ARDS survivors have a self reported quality of life significantly below published population norms and the general population. In a prospective, matched-parallel cohort study of 73 ARDS patients and 73 matched ICU patients, survivors of ARDS had statistically and clinically significant reductions in their self perceived quality of life.24 Patients reported the most significant reduction in the quality of their life was related to physical limitations that impaired their ability to perform specific roles in society.

Clinical Implications

Unless the patient or family raises specific questions early in the course of treatment, discussions on the benefits and burdens of continued treatment and estimations of the post discharge rehabilitation process and quality of life rarely occur, and if these discussions do occur it's often late in the hospitalization.26 Critical care clinicians must initiate these discussions early, and continue them on a frequent and regular basis with ARDS patients and their families. Most patients and families want some kind of benchmark as to where they can expect to be (physically and mentally) at a certain point in their recovery process. Based on the results from these studies, it may be realistic to tell them the recovery and rehabilitation process after ARDS may take a year or longer, and that includes the possibility that they may not return to work within the year. They need to know that it may take a year for cognitive deficits and quality of life to return to their baseline level.

Because studies reveal that physical limitations continue almost a year after discharge and that these limitations significantly impact quality of life, we need to evaluate physical activity in the ICU. Are there additional physical therapies that can be done in the ICU to minimize the muscle loss and weakness that occur? Are there additional interventions we can do to decrease the cognitive impairment?

The magnitude and severity of cognitive impairment of ARDS survivors at the time of hospital discharge has implications for how and when we complete discharge instructions. If these instructions are verbally communicated to the patient, it is very likely they will not remember them. The cognitive impairments, frequently under-recognized by acute care clinicians, may also be under-recognized by rehabilitation and primary care providers who care for ARDS survivors after discharge. A recent study revealed that only 12% of ARDS survivors in a rehabilitation facility received cognitive testing.22 As a result, the investigators recommend referral of ARDS survivors to rehabilitation facilities, not only for physical disabilities and weakness, but also for cognitive impairments. Pulmonary rehabilitation and behavior therapy appear to improve patients with chronic obstructive lung disease,27 and may also be beneficial for ARDS survivors.28

Since long-term follow up of ARDS survivors is usually by primary care clinicians, increased communication between caregivers about the potential for continued and late sequelae is needed to optimize care.28

The physical, psychosocial and cognitive impairments that ARDS survivors have are problematic for numerous reasons and contribute to decreased occupational capacity, decreased health related quality of life, and increased strain on family and utilization of resources. Additional research is needed to help understand, recognize, and intervene in ways that will minimize the development and consequences of prolonged impairment. Increasing knowledge in these areas will help us to improve long-term patient centered outcomes ARDS survivors.

References

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