[Diagnostic tools of intensive care unit acquired weakness: a systematic review]

To explore effective and objective diagnostic tools for evaluating intensive care unit acquired weakness (ICUAW).

The studies about evaluation and diagnosis of adult ICUAW in PubMed, Embase, Web of Science, the Cochrane Library, CNKI, CBM, VIP and Wanfang databases from the date of their foundation to July 1st in 2018 were retrieved by computer. The literatures in Chinese and English were searched. Two investigators independently screened literature and evaluated the literature quality ratings, and extracted the research design, sample size, research object, evaluation item, reliability, validity, clinical application and other indicators, and then systematically analyzed the reliability and validity of ICUAW diagnostic tools, and evaluated diagnostic tools' advantages, disadvantages and application status.

There were 19 literatures including 14 assessment scales and ultrasound diagnosis. The 14 assessment scales were medical research council score (MRC-Score), Barthel index (BI), 6-minute walk test (6MWT), clinical outcome variables scale (COVS), the Chelsea critical care physical assessment tool (CPAx), functional independence measure (FIM), functional status score for the intensive care unit (FSS-ICU), the ICU mobility scale (IMS), rivermead mobility index (RMI), the Perme ICU score (PERME), the physical function ICU test (PFIT), the physical function ICU test score (PFIT-s), the surgical ICU optimal mobility score (SOMS), and the Manchester mobility score (MMS). Nine scales (60%) were tested reliability and the rang of inter-rater reliability was 0.600-0.996, and the test reliability was 0.970, and the range of internal consistency reliability was 0.680-0.992. Validity of 6 scales (40%) were evaluated, and the range of structure validity was 0.57-0.94, the range of content validity was 0.830-0.988, the range of concurrent validity was 0.730-0.823. It was shown that the reliability of ICUAW assessment scale was relatively good at present, but the degree of accurate assessment of ICUAW was relatively low. The evaluation content of ICUAW can be divided into three categories: in the first, they measured the muscles strength of body just like MRC-Score; in the second, they evaluated the physical function and mobility, such as COVS, CPAx, FIM, FSS-ICU, IMS, PERME, PFIT, RMI, SOMS and MMS; in the third, they evaluated daily activity and physiology parameter just as 6MWT, BI and ultrasound. Different scales were correlated with the length of ICU stay (ICU-LOS), the hospital discharge, and the mortality. For example: COVS, CPAx, FSS-ICU, PFIT, PFIT-s and SOMS could predict the ICU-LOS and hospital discharge, RMI and SOMS can predict patient mortality. However, there was no evidence to testify the consistency between them. Now, the specialist consensus about the observation nodes of threshold and electrophysiological records were the complex action potential (CMAP) range < 0.43-0.65 mV and the sensory nerve action potential (SNAP) range < 17.6 μV.

There are many diagnostic tools in ICUAW, and the reliability of each scale is relatively good. In future studies, we should collect the advantages of each scale, explore the specific indicators to evaluate ICUAW and improve the accuracy and validity of diagnostic ICUAW.