Unraveling the myriad contributors to persistent diminished exercise capacity after critical illness

Abstract

''Lack of activity destroys the good condition of every human being, while movement and methodical physical exercise save it and preserve it'' (Plato).In an article recently published in Intensive Care Medicine [1], Cerqueira Borges and colleagues report their results on measuring daily life physical activity levels, muscle strength, and exercise capacity in survivors of severe sepsis and septic shock. Measurements were taken on the ward for 12 h after ICU discharge and then again at 3 months after discharge at the patients' home and over a time period of 2 days using physical activity monitors worn by the patients. Various activities including sitting, lying, standing, walking, and changes in body position and energy expenditure were recorded. Values obtained during this 2-day period were compared with those of a control group of 50 healthy sedentary subjects. During hospitalization, patients spent 90 % of their time lying in bed or sitting. Physical activity improved to 3 months but ICU patients achieved only 63 % of the walking time compared to healthy sedentary subjects. Exercise capacity was evaluated using the 6-min walk distance (6MWD) test. Dominant upper (hand) and lower (quadriceps) limb muscle strength was quantified using a digital dynamometer, and inspiratory muscle strength was captured by measuring maximal inspiratory pressure. These data were compared with age-and sex-matched control reference data. Exercise capacity, limb and inspiratory muscle strength were reduced by half compared to predicted values and improved to 70 % of predicted values by 3 months. Therefore, even several months after discharge from the hospital, the time spent in physical activities and measured muscle strength were considerably lower when compared to those of healthy people. Similar data were obtained by Denehy and colleagues in a prospective cohort study of 49 critically ill patients with varied ICU admission diagnoses [2]. Twenty-four percent of patients had significant weakness during the ICU stay. At 2 months after discharge, participants wearing an accelerometer for a mean of 13 h per day for 7 days spent 90 % of their time inactive and only 3 % of their time was spent walking. The 6MWD was 64 % of predicted normal values. Persistently diminished exercise capacity may be a robust theme across different disease states and not just affecting those patients after critical illness. In a series of COPD patients suffering acute exacerbations, patients had very low levels of physical activity during and after hospitalization captured by activity monitors [3]. The accuracy of these activity monitors in detecting the time spent in walking, different postures, counting steps, and estimating the energy

Neurological complications of sepsis

“…There are myriad contributors to the persistence of reduced muscle and strength, and diminished exercise capacity after sepsis [97], and include the severity of the ICUAW and underlying cause. The multicentre Italian study CRIMYNE (CRitical Illness MYopathy and/or Neuropathy) found that CIM has a better prognosis than CIP [100][101][102]. Physical impairment substantially impacts the quality of life [74,97,98,103] and joblessness [95,102,104,105].…”

A guided approach to diagnose severe muscle weakness in the intensive care unit

“…There can be several reasons for this, not least that the outcome is affected by a myriad of factors. ( 18 )…”