Use of non-invasive-stimulated muscle force assessment in long-term critically ill patients: a future standard in the intensive care unit?
BACKGROUND
This study's main purpose was to test the feasibility of employing a non-invasive-stimulated muscle force assessment approach in long-term critically ill patients.


METHODS
A case series was performed over a 4-year period in the intensive care unit (ICU). Of the 25 patients initially recruited, eight patients required long-time mechanical ventilation for a median of 3.8 weeks (range 2-10 weeks) and were immobilized for 5 weeks (range 2-10 weeks). With a previously tested non-invasive measuring device, we weekly assessed peak torques and rates of force development and relaxation of patients' ankle dorsiflexor contractile responses, induced via peroneal nerve stimulation. Subsequently, we derived each patient's time course of observed progressive weakness and/or recovery.


RESULTS
During their critical illnesses, seven out of eight patients elicited significant decreases in measured peak torques. In survivors (n = 6) during their recovery periods, torques gradually recovered. In the two patients who died, their strengths decreased continuously until death. The rate of force development data elicited similar trends as peak torque responses, whereas relative relaxation rates differed more widely between individuals.


CONCLUSIONS
This approach of non-invasive-stimulated muscle force assessment can be used in long-term critically ill patients and may eventually become a standard in the intensive care unit, e.g. for assessing recovery. This method is easy to employ, reproducible, provides important phenotypic quantification of skeletal muscle contractile function, and can be used for long-term outcomes assessment.
Ginz
H F
HF
Department of Anaesthesia and Research, University of Basel, Loerrach, Germany. ginz.hans-friedrich@klinloe.de
Iaizzo
P A
PA
Urwyler
Albert
A
Pargger
H
H
D000328:Adult; D000368:Aged; D003289:Convalescence; D003422:Critical Care / Q000379:methods* / Q000592:standards; D016638:Critical Illness; D018450:Disease Progression; D004568:Electrodiagnosis / Q000379:methods*; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009126:Muscle Relaxation / Q000502:physiology; D053580:Muscle Strength; D053581:Muscle Strength Dynamometer; D018908:Muscle Weakness / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology; D018482:Muscle, Skeletal / Q000294:innervation / Q000503:physiopathology*; D010543:Peroneal Nerve / Q000503:physiopathology*; D011115:Polyneuropathies / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology; D011175:Positive-Pressure Respiration; D011237:Predictive Value of Tests; D019415:Torque; D016896:Treatment Outcome