Dr Jenny Mackney

Purpose: To compare the physical function on ICU discharge in adults who survived an ICU admission for acute lung injury (ALI) with those admitted for a critical illness other than ALI. Materials and Methods: Two groups were recruited, (i) those who survived an ICU admission for ALI and, (ii) those who survived an ICU admission for a critical illness other than ALI. Within 7 days of discharge from ICU, in all participants, measures were collected of peripheral muscle strength, balance, walking speed and functional exercise capacity. Results: Recruitment was challenging and ceased prior to achieving the desired sample size. Participants with ALI (n = 22) and critical illness (n = 33) were of similar median age (50 vs. 57 yr, p = 0.09), sex proportion (males %, 45 vs. 58, p = 0.59) and median APACHE II score (21.5 vs. 23.0, p = 0.74). Compared with the participants with critical illness, those with ALI had lower hand grip (mean ± SD, 18 ± 9 vs. 13 ± 8 kg, p = 0.018) and shoulder flexion strength (10 ± 4 vs. 7 ± 3 kg, p = 0.047), slower 10-meter walk speed (median [IQR], 1.03 [0.78 to 1.14] vs. 0.78 [0.67 to 0.94] m/s, p = 0.039) and shorter 6-minute walk distance (265 [71 to 328] vs. 165 [53 to 220] m, p = 0.037). The Berg balance scores were similar in both groups. Conclusions: Compared with survivors of a critical illness that is not ALI, those with ALI are likely to have greater physical impairment when measured shortly after discharge to the ward.

Purpose: This study compared exercise responses in individuals who had recently survived an admission to the intensive care unit for acute lung injury (ALI) with healthy controls. Methods: Ten patients with ALI were recruited at 2 Australian hospitals. Six weeks after hospital discharge, participants completed lung function measures and a laboratory-based cardiopulmonary exercise test. Identical measures were collected in 21 healthy participants of similar age and gender distribution. Results: Compared with the healthy participants, the ALI participants were similar in age (51 ± 14 vs 50 ± 16 yr), with a lower peak oxygen uptake (o2) (median [interquartile range], 31.80 [26.60-41.73] vs 17.80 [14.85-20.85] mL/kg/min; P <.01) and higher ventilatory equivalent for carbon dioxide (e/co2) at anaerobic threshold (mean ± SD, 25.7 ± 2.5 vs 35.2 ± 4.1; P <.01). Analysis of individual ALI participant responses showed that 8 participants had a decreased peak o2 and anaerobic threshold. All ALI participants were limited by leg fatigue. Abnormalities of pulmonary gas exchange were present in 7 participants. Evidence of cardiac ischemia was present in 2 participants. Conclusions: Compared with healthy controls, ALI participants had reduced exercise capacity, mainly due to profound deconditioning. Exercise training to optimize aerobic capacity would appear to be a rehabilitation priority in this population.

Background. People who have had a prolonged admission to an intensive care unit (ICU) commonly have profound debilitation and weakness. For the delivery of effective exercise training, an accurate assessment of exercise capacity is essential. Objective. The study objectives were to investigate how much ground-based walking is undertaken by inpatients recovering from critical illness within 1 week of discharge from an ICU and to evaluate the feasibility and safety of the Six-Minute Walk Test (6MWT) for this population. Design. This was an observational study. Methods. Within 1 week of discharge from the ICU, functional exercise capacity was measured with the 6MWT. The maximum distance ambulated on the ward in a single session as part of usual clinical management was extracted from the medical notes. The distance achieved during the 6MWT and the maximum distance ambulated on the ward were compared. Results. The participants (N=23) were survivors of a critical illness; their mean age was 57 years (SD = 11). The median length of ICU stay was 11 days (interquartile range [IQR]=7). The mean 6-minute walk distance (6MWD) was 179 m (SD = 101), and the maximum distance ambulated on the ward was 30 m (IQR=65). There was a moderate association between the distance participants ambulated on the ward and the 6MWD (r=.54). The maximum distance ambulated on the ward, expressed as a percentage of the 6MWD, was 29% (IQR=34%). Five participants (22%) experienced oxygen desaturation (oxygen saturation of <85%) and recovered within 1 minute of resting. Limitations. The maximum distance ambulated on the ward was estimated with premeasured distances. Conclusions. Most participants ambulated at a low percentage of their measured exercise capacity. The 6MWT appears to be a safe and useful test for inpatients recently discharged from the ICU.