Methods:
A prospective descriptive design was used to examine perceived stress and sleep efficiency in family caregivers of ICU patients. The sample (n=5) was drawn from spouses of critically ill, mechanically ventilated patients that were assigned to the control group of a randomized parent study to determine feasibility of a stress management intervention. Eligibility criteria included: assigned to the control group; spousal caregiver role of a mechanically ventilated, critically ill patient; aged 18 years or older; understands and speaks English; not currently being treated for a PICS-F condition; enrollment within the first 36 hours of patient ICU admission; and impending death of the patient is not expected by the critical care attending physician. Symptoms of stress were quantified using the perceived stress scale (PSS),22 which is a 10-item measure with a total score range of 0-40, with a normative mean score of < 12.0 ± 6.9. It is intended to capture the degree to which persons perceive situations in their life as excessively stressful relative to their ability to cope. PSS baseline data were collected in the ICU on study day 1 and repeated on study day 3. A wrist ActiWatch was placed on the subject during study enrollment. Actigraphy is frequently used as a measure of sleep/rest in clinical research. The accuracy of actigraphy (0.863), sensitivity (0.965), and specificity (0.329) are weakly correlated with polysomnography.23, 24 Sleep data were measured continuously in the ICU over study day 1 through study day 3. Sleep efficiency (ratio of total time asleep to total time in bed) was calculated. Sleep efficiency of >90% is very good, >85% is considered normal, <85% is poor, and <75% indicates insomnia. Since symptoms of PICS-F occur during the ICU and after hospital discharge, repeated measures were obtained on study day 1, study day 3, study day 30, and study day 90 using the NIH Toolbox Emotion Battery (version 1.11). The battery is made up of four subdomains including Negative Affect, Psychological Well-Being, Stress and Self-Efficacy, and Social Relationships.25 Data was collected from August to December in 2017. Descriptive statistics were calculated.
Results: The mean age of the sample was 50.8 ± 9.5 years, 80% were female, 100% were White, and 40% were Hispanic. Baseline mean perceived stress score was high (>12) at 15.6 ± 4.9. Baseline mean perceived stress scores ranged from 9 to 23 (median=14, no mode). Study day 3 mean perceived stress score was higher at 18.4 ± 3.8. Study day 3 mean perceived stress scores ranged from 14 to 23 (median=16, modes=16 & 23). Perceived stress was high and trended upwards during the ICU stay. Mean sleep efficiency, over the 3-day period, was poor (<85%) at 64% ± 17.8%. Sleep efficiency ranged from 40% to 90% (median=66%, no mode). One of the five subjects had normal sleep efficiency (90%); three subjects had poor sleep efficiency with insomnia (<75%), and one subject was unable to wear the ActiWatch. Repeated measures of mean scores for symptoms of PICS-F over time (study days 1, 3, 30 & 90) suggest acute stress was high (>25) during and after the ICU (26, 28.4, 26 & 25); mean scores for anxiety (>7) remained high during and after the ICU (10.6, 11, 10 & 9.3); mean scores for depression (>12) were noted during and after the ICU, and returned to normal by study day 90 (11.8, 12.6, 12 & 11.8); mean scores for posttraumatic stress (>9) remained high during and after the ICU (23.4, 27.2, 20.8 & 23.3).
Conclusion: According to the Family Caregiver Alliance, stress, depressive symptoms, and sleep disorders are the most frequent negative influences on caregiver health.26 Our study suggests elevated perceived stress levels, along with the added stress of poor sleep efficiency during the ICU stay of a loved one, place family caregiver health at risk for post intensive care syndrome, which includes acute stress disorder, ongoing anxiety, depression, posttraumatic stress disorder, and complicated grief. Moreover, caregivers who provide substantial care (i.e., care coordination and medication management) are more likely to have physical and emotional health problems.27 Patients who survive critical illness require substantial care. Therefore, interventions are warranted that reduce stress and enhance sleep during the ICU stay to lower risk of PICS-F and promote family caregiver health.
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