Link between muscle function and physical function in critically ill patients

Date
2021-03
Journal Title
Journal ISSN
Volume Title
Publisher
Stellenbosch : Stellenbosch University
Abstract
ENGLISH SUMMARY : Introduction: Improvements in intensive care unit (ICU) care has led to a growing number of survivors of critical illness, but not necessarily improved quality of life. After surviving critical illness, many critically ill survivors suffer from long-term complications such as reduced physical function, mental and cognitive dysfunction and a reduced health-related quality of life (HRQoL). Critically ill survivors develop a loss of muscle mass and muscle weakness of the respiratory and peripheral muscles. Therefore, the premise of this thesis was to determine whether muscle structure and function is associated with physical function in critically ill survivors. Methods: A scoping review was done to map the current understanding of muscle structure and function in critically ill patients. Six databases were searched using a data-base specific search strategy and papers were identified based on a familiarity with the literature. The primary investigator (PI) used a systematic process to extract data into a self-developed excel spreadsheet. The data obtained were used to inform the planning of the primary research study. A prospective observational cohort study was conducted to describe the outcomes of critically ill patients as well as determine the correlation between muscle structure, muscle function and physical function in critically ill patients at ICU discharge and hospital discharge. Mechanically ventilated participants were recruited within 24 hours of admission to the ICU. Measurements taken of muscle structure and function included ultrasonography of the diaphragm and peripheral muscles, the Medical Research Council- Sum Score (MRC-SS), dynamometry, maximal inspiratory pressure (MIP) and respiratory muscle endurance. The physical function and HRQoL measurements included the Chelsea Critical Care Physical Assessment (CPAx) tool, the de Morton Mobility Index (DEMMI), the Six-Minute Walk Test (6-MWT) and the EQ-5D-5L questionnaire. Associations between measures of muscle structure, muscle function and physical function were reported using Spearman’s correlations. Results: One thousand two hundred and eighty-two studies were retrieved and assessed for inclusion into the scoping review. After assessing for eligibility, thirty-four studies were included in the review. Data regarding muscle structure and function were predominantly from the developed countries. Assessments were focused on either muscle structure or muscle function, and not both. The methodology for the assessments of muscle structure and function were not standardised. Majority of assessments took place during ICU stay. The postural muscles were the least investigated. Forty-five participants were recruited for the primary research study. The median age of the sample was 34.5 (24.3 - 47.4) years. Participants presented with changes in respiratory and peripheral muscle structure and function, and in physical function. A strong positive correlation was established between MIP and the 6-MWT (rho = 0.75, p < 0.01). Conclusion: The methodologies used to measure muscle structure and function were not standardised and the discrepancy in results hampered our current understanding of muscle structure and function in critically ill patients. Muscle structure and function may partially explain physical function outcomes in survivors of critical illness, but other variables need to be considered.
AFRIKAANSE OPSOMMING : Inleiding: Verbeterings in intensiewesorgeenheid (ISE) sorg het gelei tot 'n groeiende aantal oorlewendes van kritieke siektes, maar nie noodwendig verbeterde lewensgehalte nie. Na die oorlewing van kritieke siekte, baie krities siek oorlewendes ly aan langtermyn komplikasies, soos verminderde fisiese funksie, geestelike en kognitiewe disfunksie, en 'n verminderde gesondheidsverwante lewensgehalte (HRQoL). Krities siek oorlewendes ontwikkel 'n verlies van spiermassa en spierswakheid van die respiratoriese en perifere spiere. Daarom was die uitgangspunt van hierdie proefskrif om te bepaal of spierstruktuur en funksie geassosieer word met fisiese funksie in kritiek- siek oorlewendes. Metodes: 'n literatuuroorsig is uitgevoer om die huidige begrip van spierstruktuur en -funksie by kritiek siek pasiënte te bepaal. Ses databasisse is deursoek met behulp van 'n spesifieke soekstrategie. Artikels is geïdentifiseer van 'n vertroudheid met die literatuur. Die primêre ondersoeker (PI) het 'n sistematiese proses gebruik om data in 'n selfontwikkelde Excel-sigblad te onttrek. Die data wat verkry is, is gebruik om die beplanning van die primêre navorsingstudie te rig. 'n Voornemende waarnemings kohort studie is uitgevoer om die uitkomste van krities siek pasiënte te beskryf, asook om die korrelasie tussen spierfunksie en fisiese funksie in krities siek pasiënte tydens ISE-ontslag en hospitaal-ontslag te bepaal. Meganiese geventileerde deelnemers is binne 24 uur na toelating tot die ISE gewerf. Metings van spierstruktuur en funksie sluit in ultrasonografie van die diafragma en perifere spiere, mediese navorsing raad-som telling (MRC-SS), dinamometrie, maksimum inspirerende druk (MIP) en respiratoriese spiere uithouvermoë. Die fisiese funksie en HRQoL-metings het ingesluit die Chelsea Kritieke Sorg Fisiese Assesserings (CPAx) instrument, die de Morton Mobiliteits indeks (DEMMI), die Ses-Minute Staptoets (6-MWT) en die EQ-5D-5L-vraelys. Verbindings tussen maatstawwe van spierstruktuur, spierfunksie en fisiese funksie is aangemeld met behulp van Spearman se korrelasies. Stellenbosch Resultate: Een duisend twee honderd twee-en-tagtig studies is opgespoor en geassesseer vir insluiting in die literatuuroorsig. Na die sifting is vier-en-dertig studies ingesluit. Data met betrekkiing tot spierstruktuur en -funksie was hoofsaaklik uit die ontwikkelde lande. Assesserings was gefokus op spierstruktuur of spierfunksie, en nie albei nie. Die metodologie vir die assesserings van spierstruktuur en -funksie is nie gestandaardiseer nie. Meerderheid van die assesserings het plaasgevind tydens ISE verblyf. Die posturale spiere was die minste ondersoek. Vyf en veertig deelnemers is vir die primêre navorsingstudie gewerf. Die mediaanouderdom van die steekproef was 34.5 (24.3 - 47.4) jaar. Deelnemers het aangebied met gestremdhede in spierstruktuur, spierkrag en fisiese funksie.'n Sterk positiewe korrelasie is vasgestel tussen MIP en die 6 MWT (rho = 0.75, p <0.01). Gevolgtrekking: Die metodologieë wat gebruik word om spierstruktuur en -funksie te meet is nie gestandaardiseer nie en die verskil in resultate belemmer ons huidige begrip van spierstruktuur en -funksie by kritiek siek pasiënte. Spierstruktuur en -funksie kan die fisieke funksie-uitkomste gedeeltelik by oorlewendes van kritieke siekte verklaar, maar ander veranderlikes moet in ag geneem word.
Description
Thesis (MScPhysio)--Stellenbosch University, 2021.
Keywords
Catastrophic illness -- Patients, Muscle strength, Respiratory muscles, Intensive care units, UCTD
Citation