TY - JOUR
T1 - Biomechanical and nonfunctional assessment of physical capacity in male ICU survivors
AU - Poulsen, Jesper Brøndum
AU - Rose, Martin Høyer
AU - Jensen, Bente Rona
AU - Møller, Kirsten
AU - Perner, Anders
N1 - CURIS 2013 NEXS 019
PY - 2013/1
Y1 - 2013/1
N2 - OBJECTIVES:: ICU admission is associated with decreased physical function for years after discharge. The underlying mechanisms responsible for this muscle function impairment are undescribed. The aim of this study was to describe the biomechanical properties of the quadriceps muscle in ICU survivors 12 months after ICU discharge. DESIGN:: Case-control study with consecutive inclusion of ICU survivors and age-and sex-matched controls. SETTING:: Patients were treated at a mixed 18-bed ICU at a tertiary care university hospital and tested at a biomechanical university laboratory. PATIENTS:: We included 16 male ICU patients (Acute Physiology and Chronic Health Evaluation II score 20 ± 7, mean ± SD), who had stayed in the ICU >72 hrs and survived to 12 months and 15 age-and sex-matched controls. INTERVENTIONS:: None. MEASUREMENTS AND MAIN RESULTS:: An extensive battery of biomechanical tests, including maximum, fast, and endurance contractions, was administered during isometric knee extensions while simultaneously recording surface electromyography (quadriceps and hamstrings). Compared to controls, ICU survivors had reduced maximal voluntary torque (22%, 179 ± 64 Nm vs. 230 ± 57 Nm, p = 0.03), absolute rate of force development (50%, 868 ± 372 Nm/sec vs. 1739 ± 470 Nm/sec, p < 0.001) and relative rate of force development (32%, 512 ± 260% maximum voluntary contraction/sec vs. 754 ± 189% maximum voluntary contraction/sec, p < 0.01), and endurance time (40%, 136 ± 84 sec vs. 226 ± 111 sec, p < 0.02). Rate of force development, but not maximal voluntary torque, was significantly reduced after adjusting for muscle mass. Electromyography data indicated no impairment of motor activation strategy or central motor drive. Also, no difference in reaction time was found between patients and controls. CONCLUSIONS:: ICU survivors had reduced rate of force development and muscular endurance 1 yr after ICU discharge. Our data indicate that the functional deficits experienced by ICU survivors originate in muscle tissue rather than the nervous system. Also, increased attention to velocity-orientated exercise during rehabilitation of ICU patients may have the potential to better physical outcome after critical illness.
AB - OBJECTIVES:: ICU admission is associated with decreased physical function for years after discharge. The underlying mechanisms responsible for this muscle function impairment are undescribed. The aim of this study was to describe the biomechanical properties of the quadriceps muscle in ICU survivors 12 months after ICU discharge. DESIGN:: Case-control study with consecutive inclusion of ICU survivors and age-and sex-matched controls. SETTING:: Patients were treated at a mixed 18-bed ICU at a tertiary care university hospital and tested at a biomechanical university laboratory. PATIENTS:: We included 16 male ICU patients (Acute Physiology and Chronic Health Evaluation II score 20 ± 7, mean ± SD), who had stayed in the ICU >72 hrs and survived to 12 months and 15 age-and sex-matched controls. INTERVENTIONS:: None. MEASUREMENTS AND MAIN RESULTS:: An extensive battery of biomechanical tests, including maximum, fast, and endurance contractions, was administered during isometric knee extensions while simultaneously recording surface electromyography (quadriceps and hamstrings). Compared to controls, ICU survivors had reduced maximal voluntary torque (22%, 179 ± 64 Nm vs. 230 ± 57 Nm, p = 0.03), absolute rate of force development (50%, 868 ± 372 Nm/sec vs. 1739 ± 470 Nm/sec, p < 0.001) and relative rate of force development (32%, 512 ± 260% maximum voluntary contraction/sec vs. 754 ± 189% maximum voluntary contraction/sec, p < 0.01), and endurance time (40%, 136 ± 84 sec vs. 226 ± 111 sec, p < 0.02). Rate of force development, but not maximal voluntary torque, was significantly reduced after adjusting for muscle mass. Electromyography data indicated no impairment of motor activation strategy or central motor drive. Also, no difference in reaction time was found between patients and controls. CONCLUSIONS:: ICU survivors had reduced rate of force development and muscular endurance 1 yr after ICU discharge. Our data indicate that the functional deficits experienced by ICU survivors originate in muscle tissue rather than the nervous system. Also, increased attention to velocity-orientated exercise during rehabilitation of ICU patients may have the potential to better physical outcome after critical illness.
U2 - 10.1097/ccm.0b013e31826a3f9e
DO - 10.1097/ccm.0b013e31826a3f9e
M3 - Journal article
C2 - 23222267
SN - 0090-3493
VL - 41
SP - 93
EP - 101
JO - Critical Care Medicine
JF - Critical Care Medicine
IS - 1
ER -