Thesis (MScPhysio)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Introduction: In the intensive care unit population, approximately 40% of patients require
mechanical ventilation and 20-25% of these patients will encounter difficulties in the
discontinuation of mechanical ventilation. As mechanical ventilation affects the diaphragm, a
better understanding of the structural and functional changes of the diaphragm is warranted.
Method: A scoping review was done to determine whether a relationship between
diaphragm thickness, diaphragm strength and diaphragm endurance had been established.
Seven databases were searched using a specific search strategy. Papers were identified
based on pre-defined inclusion criteria. Data was extracted by the primary investigator (PI)
into a self-developed excel spreadsheet. Criteria were developed for a more focused review
to inform the planning of a primary study. The primary study investigated the relationship
between diaphragm thickness, diaphragm strength and diaphragm endurance in young,
healthy individuals. A sample of convenience was used; included healthy individuals (18-24);
three activity-levels (sedentary; endurance- and strength related sporting activities); stratified
for gender and BMI. Measurements included: Sonographic measurement of diaphragm
thickness; mouth pressure manometer measurements for diaphragmatic strength; and
fatigue resistance index as a measure of endurance. Participants were instructed to breathe
through a pressure threshold device at 60% of PImax until task failure. The fatigue resistance
index was calculated as PImax final/PImax initial. Intra-rater reliability was established and
testing procedures standardised a priori. Results: 405 full texts were retrieved and assessed for inclusion into the review. Papers
identified the evaluation of diaphragm function in a variety of populations. 23 papers were
included in the focused review. Six papers were published on diaphragm thickness, six on
diaphragm strength and eleven on diaphragm endurance. No papers identified the
correlation between diaphragm thickness, diaphragm strength and diaphragm endurance. 55
subjects, males and females, were recruited for the primary study. Groups were similar at
baseline with regards to gender, age and BMI. The mean age of the sample was 21.16 years
(SD = 1.55), with a mean body mass index (BMI) of 25.43 kg/m2 (SD = 3.70). A moderate
positive correlation was established between diaphragm thickness and diaphragm strength
measurements (r = 0.52; r2 = 0.27; p < 0.01). Diaphragm thickness was not correlated with
diaphragm endurance (r = -0.15; r2 = 0.02; p = 0.29). No relationship was found between the
strength of the diaphragm and the endurance of the diaphragm (r= -0.19; r2 = 0.04; p= 0.16). Conclusion: Guidelines for the measurement of diaphragm function do exist, but they are
not adhered to by the majority of studies. Study procedures are inconsistently reported and
this may affect the reproducibility of techniques in future studies. We further conclude that a
correlation exists between diaphragm thickness and diaphragm strength. The use of
ultrasound to measure diaphragm thickness proved to be a reliable technology and gave a
moderate indication of the strength of the diaphragm. This technology may help clinicians to
detect and monitor dysfunction of the diaphragm in the early stages of admission to the
acute setting. / AFRIKAANSE OPSOMMING: Inleiding: Ongeveer 40% van pasiente wat in intensiewe sorgeenheid behandel word,
benodig intubasie en meganiese ventilasie. Tot 25% van hierdie pasiënte sal probleme
ondervind in die staking van meganiese ventilasie. Meganiese ventilasie beïnvloed die
diafragma, daarom word n beter begrip van die strukturele en funksionele veranderinge van
die diafragma benodig.
Metode: 'n Literatuur oorsig is gedoen om te bepaal of daar 'n verhouding bestaan tussen
die dikte, krag en uithouvermoë van die diafragma. Sewe databasisse is deurgesoek aan die
hand van spesifieke databasis gedefinieerde soektog strategie. Relevante artikels is
geïdentifiseer aan die hand van pre-gedefinieerde insluiting kriteria. Data is onttrek en in ‘n
self-ontwikkelde datablad opgesom deur die primêre ondersoeker (PI). Hierdie inligting is
gebruik in die beplanning van ‘n primêre studie. Die doel van die primêre studie was om die
verhouding tussen die diafragma dikte, krag en uithouvermoë in jong, gesonde individue te
ondersoek. ‘n Gerieflikheids steekproef is gebruik; insluitend gesonde individue (18-24); drie
aktiwiteits vlakke (passief; uithouvermoë- en krag verwante sportaktiwiteite) en breë
spektrum vir geslag en ligaamsbou (BMI). Metings ingesluit: sonografiese meting van die
diafragma se dikte; monddruk manometer metings vir diafragmatiese krag en ‘n
moegheid/weerstand indeks as maatstaf van diafragmatiese uithouvermoë. Deelnemers is
opdrag gegee om asem te haal deur toestel met druk maksimum gestel 60% van PImax, tot
mislukking. Die moegheid/weerstand indeks is bereken as PImax finale / PImax oorspronlik.
Intra-meter betroubaarheid is bepaal en toets prosedures is gestandaardiseer voordat data
ingesamel is. Resultate: 405 vol teks artikels is uitgelig vir insluiting in die literatuur oorsig. Diafragmatiese
funksie is ge-evalueer in 'n verskeidenheid bevolkings. Drie en twintig artikels is in die finale
oorsig ingesluit. Ses artikels wat diafragma dikte evalueer, ses wat diafragmatiese krag
evalueer en elf wat die diafragma se uithouvermoë evalueer is ingesluit in die oorsig. Geen
van die artikels uitgelig het ‘n ooreenkoms tussen diafragma dikte, diafragma krag en
diafragma uithouvermoë geïdentifiseer nie. 55 deelnemers is gewerf vir die primêre studie.
Groepe was soortgelyk by basislyn met betrekking tot geslag, ouderdom en BMI. Die
gemiddelde ouderdom van die toetsgroep was 21.16 jaar (SD=1.55), met 'n gemiddelde BMI
van 25.43 kg/m2 (SD = 3.70). ‘n Middelmatige positiewe verhouding is waargeneem tussen
diafragma dikte en krag (r = 0.52; r2 = 0.27; p < 0.01). Geen verhouding is gevind tussen
diafragma dikte en uithouvermoë nie (r= -0.15; r2 = 0.02; p = 0.29). Daar is ook geen verhouding waargeneem tussen diafragma krag en diafragma uithouvermoë nie. (r= 0.19; r2
= 0.04; p = 0.16).
Gevolgtrekking: Daar bestaan wel riglyne vir die meting van die diafragma se funksie, maar
in die meerderheid van studies word dit nie nagekom nie. Studie prosedures is nie
konsekwent weergegee nie en dit kan die resultate van tegnieke beinvloed in toekomende
studies. ‘n Matige sterk verhouding is waargeneem tussen diafragmatiese dikte en krag. Die
gebruik van ultraklank om die diafragma se dikte te meet is betroubare tegnologie en kan n
redelike aanduiding gee oor die krag van die diafragma. Hierdie tegnologie kan praktisyne
help om enige disfunksie van die diafragma te identifiseer en te monitor in die vroeë
stadiums van toelating tot die akute omgewing.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/86666 |
| Date | 04 1900 |
| Creators | Orrey, Samantha Taylor |
| Contributors | Hanekom, S. D., Unger, M., Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Interdisciplinary Health Sciences. Physiotherapy. |
| Publisher | Stellenbosch : Stellenbosch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | Unknown |
| Type | Thesis |
| Format | 114 p. : ill. |
| Rights | Stellenbosch University |
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