Evaluating the musculoskeletal health state of Intensive Care Unit Survivors: The MSK-ICU study

Background Survivors of critical illness frequently experience long-term physical impairment, decreased health related quality of life (QoL) and low rates of return to employment.

There has been limited investigation of the underlying problems affecting physical function post-Intensive Care Unit (ICU) admission. Recent post-ICU rehabilitation studies have failed to demonstrate improvements in physical function.

To develop effective rehabilitation interventions to improve long term physical function and QoL post-ICU, more detail regarding the underlying reasons for physical impairment needs to be established.

Musculoskeletal (MSK) conditions are wide raging, with ICU survivors potentially at risk of their development due to the rapid muscle mass loss seen in ICU.

A small number of studies in ICU survivors have identified some MSK complications, however the MSK health state and its impact on physical function remains largely unknown.

Research question What is the MSK health state of, and how does it impact physical function in, ICU survivors six months after admission to ICU?

Aim and objectives The aim is to conduct a longitudinal investigation to determine and characterise the MSK health state of ICU survivors six months following admission to ICU, in order to inform future development of targeted rehabilitation interventions. The study will achieve this aim through the following objectives: 1.

Quantify the MSK health state using the MSK Health Questionnaire (MSK-HQ) and assess its relationship with QoL, employment, anxiety and depression, and symptoms of post-traumatic stress disorder (PTSD). 2. Identify prognostic factors for a lower MSK-HQ score after critical illness. 3.

Characterise the specific MSK complications experienced by patients using a standardised comprehensive MSK assessment. 4.

Evaluate patient mobility and upper limb function, and the extent of the relationship to muscle structure and function in those patients with poor MSK health state.

Methods The proposed study is a multicentre prospective longitudinal cohort study with three components to address the study objectives.

Objective 1 & 2 Baseline measurement prior to hospital discharge of 400 patients from three centres with an ICU length of stay of greater than 48 hours, and a telephone follow-up at six months post-ICU admission.

MSK health state will be measured by the MSK-HQ, with measurements of health related QoL, employment, anxiety and depression and symptoms of PTSD also collected. Multivariable linear regression will be used to identify prognostic factors for a lower MSK-HQ score.

Objective 3 A detailed MSK physical assessment of: pain; peripheral joint range of movement; and strength in 150 patients.

Objective 4 A detailed assessment of mobility, function and muscle architecture and function in 35 patients presenting with a low MSK-HQ score.

Assessments will include: muscle ultrasound; isokinetic dynamometry; exercise capacity; physical activity; participation; and upper limb function.

Anticipated impact The findings from this research will be essential in developing future rehabilitation interventions aimed at improving long term physical function in ICU survivors.

This will subsequently improve patients QoL, expedite return to work and decrease healthcare and social services utilisation.