Effects of early, combined endurance and resistance training in mechanically ventilated, critically ill patients: a study protocol for a randomised controlled trial

BACKGROUND Prolonged need for intensive care is associated with neuromuscular weakness, termed Intensive Care Unit Acquired Weakness. Those affected suffer from severe functional impairment that can persist for years. First studies suggest a positive effect of physiotherapy and early mobilisation. However, the ideal intervention for a preferential functional outcome is not known. So far no randomised controlled trial has been conducted to specifically evaluate an early endurance and resistance training in the mechanically ventilated, critically ill patient. METHODS/DESIGN A randomised controlled trial with blinded assessors and 6-month follow-up will be conducted in a tertiary, interdisciplinary intensive care unit in Switzerland. Participants (n = 115; expected dropouts: n = 15) will be randomised to a control group receiving standard physiotherapy and to an experimental group that undergoes early mobilisation combined with endurance and resistance training. The inclusion criteria are being aged 18 years or older, expected mechanical ventilation for more than 72 h and qualitative independence before the illness. Primary endpoints are functional capacity (6-Minute Walk Test) and the ability to perform activities of daily living (Functional Independence Measure) measured at hospital discharge. Secondary endpoints include muscle strength (Medical Research Council sum score, handgrip strength and handheld dynamometry for quadriceps muscle), joint contractures (range of motion), exercise capacity (Timed 'Up & Go' Test) and health-related quality of life (Short Form 36). Safety will be monitored during interventions by indirect calorimetry and continuous intensive care standard monitoring. All previously defined adverse events will be noted. The statistical analysis will be by intention-to-treat with the level of significance set at p < 0.05. DISCUSSION This prospective, single-centre, allocation-concealed and assessor-blinded randomised controlled trial will evaluate participant's function after an early endurance and resistance training compared to standard care. Limitations of this study are the heterogeneity of the critically ill and the discontinuity of the protocol after relocation to the ward. The strengths lie in the pragmatic design and the clinical significance of the chosen outcome measures. TRIAL REGISTRATION German Clinical Trials Register (DRKS): DRKS00004347 , registered on 10 September 2012

RELIABILITY OF THE TOTAL BODY RECUMBENT STEPPER SUBMAXIMAL EXERCISE TEST

David R. Wilson, Anna E. Mattlage, Abdulfattah S. Alqahtani, Nicole M. Seier, Jonathan D. Todd, Brian G. Price & Sandra A. Billinger University of Kansas Medical Center, Kansas City Kansas Submaximal exercise testing presents a practical alternative for measurement of cardio-respiratory fitness in a clinical setting where peak exercise testing my not be feasible. Previously, our lab developed a prediction equation to estimate peak VO2 using a total body recumbent stepper (TBRS) based on the Young Men’s Christian Association (YMCA) protocol. The peak VO2 prediction equation was cross-validated in a group of healthy adults and in individuals 60-80 years of age. However, we have not yet tested the reliability of the TBRS submaximal exercise test. PURPOSE: The purpose of the present study was to determine the reliability of the TBRS submaximal exercise test in healthy adults from 20-70 years of age. METHODS: A total of 40 subjects (27 M, 13 F, 39.6 yrs ± 10.3) were recruited from the Kansas City Metro and surrounding area and screened to determine eligibility. Subjects completed 2 submaximal exercise tests separated by a minimum of 24 hours and a maximum of 5 days. Testing was conducted at similar times of day. Participants were informed not to consume food or drink (except water) within 2-3 hours of the exercise tests and avoid caffeinated products for 6 hours prior to the exercise test. Participants were asked to avoid vigorous physical activity for 24 hours prior to exercise testing. Height, weight, pre-exercise HR and blood pressure (BP) were obtained prior to exercise testing. Data was analyzed using SPSS for test-retest reliability with an intraclass correlation coefficient (ICC) computation. RESULTS: We found a significant correlation between predicted peak VO2 at visit 1 and visit 2 (ICC 2,1 = 0.986, CI =.974-.993). Repeated Measures ANOVA showed no significant difference in predicted values between visits (p= 0.153). CONCLUSION: These results suggest that the TBRS submaximal exercise test and peak VO2 prediction equation can be used to reliably predict peak oxygen consumption. This is essential information for clinical professionals who want to provide their patients or clients with information regarding their cardiorespiratory fitness

Safety of performing a graded exercise test early after stroke and transient ischemic attack

Background Low cardiorespiratory fitness (CRF) is a predictor of stroke risk and poor outcome poststroke. Fitness levels are rarely assessed in the acute phase and it is unclear if it is safe for stroke survivors and people with transient ischemic attack (TIA) to perform a graded exercise test to assess fitness. Objective To determine if people within 14 days post stroke can safely perform a graded exercise test. Design Observational study. Setting Research institute. Participants People with stroke or TIA admitted to an acute stroke unit. Intervention Not applicable. Main Outcome Measures Safety of performing a graded exercise test early post stroke. Safety outcomes were (1) occurrence of an adverse event or (2) <85% blood oxygen saturation (SpO2). Participants performed a graded exercise test on a recumbent stepper at a research institute <2 weeks postevent. CRF was determined by measuring peak volume of oxygen uptake (VO2peak) using a metabolic cart. Results Twenty-nine participants were enrolled in the study (median age 69 years; interquartile range 58-75). Sixteen were diagnosed with TIA and 13 with a mild stroke. Twenty-eight participants completed the test; one participant was unable to perform the test due to back pain. The test was terminated due to standardized stopping criteria in 26 cases (5 = volitional fatigue, 6 = unable to keep required cadence, 15 = reaching 85% HRmax), one due to safety (ie, SpO2 < 85%), and one was inadvertently terminated before stopping criteria were reached. Average CRF determined by the exercise test was low; mean VO2peak of 16.2 ± 4.5 mL/kg/min for men (n = 20) and 12.4 ± 3.6 mL/kg/min for women (n = 8). Conclusions Determining exercise capacity early post stroke and TIA using a graded exercise test appears to be safe in patients with mild deficits. This information should be useful to plan tailored exercise programs. Further research should focus on determining safety of exercise testing in more severely affected stroke survivors

EXERCISE INTENSITY AND MIDDLE CEREBRAL ARTERY DYNAMICS IN HUMANS

Emily Witte1, Yumei Liu1, Jaimie L. Ward1, Katie S. Kempf1, Alicen Whitaker1, Eric D. Vidoni2,Jesse C. Craig3, David C. Poole3, Sandra A. Billinger1 * 1University of Kansas Medical Center, Kansas City, KS; 2University of Kansas, Alzheimer’s Disease Center, Fairway, KS; 3Kansas State University, Manhattan, KS Understanding the middle cerebral artery dynamic response during different exercise intensities is vital for understanding brain health and designing and evaluating exercise strategies for maximizing therapeutic potential. However, whether there is an interaction between exercise intensity and cerebrovascular kinetics is unknown. PURPOSE: To characterize mean middle cerebral artery blood flow velocity (MCAv) kinetics associated with two exercise work rates: low and moderate. We tested the hypotheses that increasing work rate would increase the MCAv amplitude and that age and estimated maximal oxygen uptake (V̇O2max) would be related to the MCAv amplitude. METHODS: Baseline values were collected for 90-seconds followed by a 6-minute exercise bout on a recumbent stepper. Heart rate, end tidal CO2 (PETCO2), beat-to-beat blood pressure, and MCAV were recorded at rest and during exercise. The MCAv kinetics response for participants from baseline (BL) was described by the response amplitude (Amp), time delay (TD), and time constant (τ). RESULTS: Sixty-four adults completed the low and moderate intensity exercise transitions. MCAv Amp increased from rest as a function of work rate, low and moderate intensity, respectively, (11.8 and 14.7 cm/s; p\u3c0.001) while no difference between work rates were observed in either TD (43.5 and 45.8 s; p=0.65) or τ (35.2 and 31.4 s; p=0.47). Age showed a moderate, negative association with MCAv Amp (r=-0.40 and r=-0.42; p\u3c0.01). Higher estimated V̇O2 max demonstrated a moderate, positive correlation with MCAv Amp (r=0.41 and r=0.50; p\u3c0.01). CONCLUSION: Moderate intensity exercise induced a greater MCAv response amplitude compared to low intensity exercise. The amplitude of the initial MCAv response for both exercise intensities increased systematically with work rate whereas the TD and τ kinetics parameters were invariant. Therefore, the possibility exists that the cerebrovascular system may have protective mechanisms in place to avoid the more rapid responses as seen in skeletal muscle, however more work is needed to address this hypothesis. Finally, although the MCAv Amp declines with age, maintaining higher cardiorespiratory fitness may benefit the cerebrovascular response to exercise. ACKNOWEDGEMENTS: S. A. Billinger was supported in part by K01HD067318 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development and from the Wohlgemuth Faculty Scholar Award. A. Whitaker and K. Kempf were supported in part by T32HD057850 from the Eunice Kennedy Shriver National Institute of Child Health and Human Development. E. D. Vidoni received partial support from the University of Kansas Alzheimer\u27s Disease Center (P30AG035982). REDCap at University of Kansas Medical Center is supported by CTSA Award # ULTR000001 from NCRR and NCATS awarded to the University of Kansas Medical Center for Frontiers: The Heartland Institute for Clinical and Translational Research. The Georgia Holland Research in Exercise and Cardiovascular Health (REACH) laboratory space was supported by the Georgia Holland Endowment Fund