Upper-extremity blood flow restriction: the proximal, distal, and contralateral effects-a randomized controlled trial.

BACKGROUND: Blood flow restriction (BFR) training with low weight is purported to induce similar physiological changes to high-weight regimens with the benefit of less tissue stress. We hypothesized that low-weight training with BFR would produce increased gains in strength and hypertrophy for muscle groups proximal, distal, and contralateral to tourniquet placement compared with low-weight training alone. METHODS: In this prospective, randomized controlled trial, healthy subjects were randomized into a 6-week low-weight training program either with or without BFR on 1 extremity. Outcome measures included limb circumference and strength. Comparisons were made between the BFR and non-BFR extremities, BFR and control groups, and non-BFR extremity and control groups. RESULTS: A total of 24 subjects (14 BFR and 10 control subjects) completed the protocol. Significantly greater gains were observed in dynamometric strength both proximal (shoulder scaption [30% greater], flexion [23%], and abduction [22%]) and distal (grip strength [13%]) to the tourniquet in the BFR limb compared with both the non-BFR extremity and the control group (P < .05). Arm and forearm circumferences significantly increased in the BFR limb compared with the non-BFR limb and control group (P = .01). The non-BFR extremity demonstrated greater grip strength than the control group (9%, P < .01). No adverse events were reported. CONCLUSION: Low-weight BFR training provided a greater increase in strength and hypertrophy in the upper-extremity proximal and distal muscle groups compared with the control group. The non-BFR extremity showed a significant increase in grip strength compared with the control group, indicating a potential systemic effect.

Proximal, Distal, and Contralateral Effects of Blood Flow Restriction Training on the Lower Extremities: A Randomized Controlled Trial.

BACKGROUND:: Blood flow restriction (BFR) training involves low-weight exercises performed under vascular occlusion via an inflatable cuff. For patients who cannot tolerate high-load exercises, BFR training reportedly provides the benefits of high-load regimens, with the advantage of less tissue and joint stress. HYPOTHESIS:: Low-load BFR training is safe and efficacious for strengthening muscle groups proximal, distal, and contralateral to tourniquet placement in the lower extremities. STUDY DESIGN:: Randomized controlled trial. LEVEL OF EVIDENCE:: Level 1. METHODS:: This was a randomized controlled trial of healthy participants completing a standardized 6-week course of BFR training. Patients were randomized to BFR training on 1 extremity or to a control group. Patients were excluded for cardiac, pulmonary, or hematologic disease; pregnancy; or previous surgery in the extremity. Data collected at baseline and completion included limb circumferences and strength testing. RESULTS:: The protocol was completed by 26 patients, providing 16 BFR and 10 control patients (mean patient age, 27 years; 62% female). A statistically greater increase in strength was seen proximal and distal to the BFR tourniquet when compared with both the nontourniquet extremity and the control group ( P < 0.05). Approximately twice the improvement was seen in the BFR group compared with controls. Isokinetic testing showed greater increases in knee extension peak torque (3% vs 11%), total work (6% vs 15%), and average power (4% vs 12%) for the BFR group ( P < 0.04). Limb circumference significantly increased in both the thigh (0.8% vs 3.5%) and the leg (0.4% vs 2.8%) compared with the control group ( P < 0.01). Additionally, a significant increase occurred in thigh girth (0.8% vs 2.3%) and knee extension strength (3% vs 8%) in the nontourniquet BFR extremity compared with the control group ( P < 0.05). There were no reported adverse events. CONCLUSION:: Low-load BFR training led to a greater increase in muscle strength and limb circumference. BFR training had similar strengthening effects on both proximal and distal muscle groups. Gains in the contralateral extremity may corroborate a systemic or crossover effect. CLINICAL RELEVANCE:: BFR training strengthens muscle groups proximal, distal, and contralateral to cuff placement. Patients undergoing therapy for various orthopaedic conditions may benefit from low-load BFR training with the advantage of less tissue stress.

Association of Admission Laboratory Values and the Timing of Endoscopic Retrograde Cholangiopancreatography With Clinical Outcomes in Acute Cholangitis.

Importance: Acute cholangitis (AC), particularly severe AC, has historically required urgent endoscopic decompression, although the timing of decompression is controversial. We previously identified 2 admission risk factors for adverse outcomes in AC: total bilirubin level greater than 10 mg/dL and white blood cell count greater than 20 000 cells/µL. Objectives: To validate previously identified prognostic factors in AC, evaluate the effect of timing of endoscopic retrograde cholangiopancreatography on clinical outcomes, and compare recent experience with AC vs an historical cohort. Design, Setting, and Participants: A retrospective analysis (2008-2015) of patients with AC (validation cohort, n = 196) was conducted at 2 academic medical centers to validate predictors of adverse outcome. Timing of endoscopic retrograde cholangiopancreatography and outcome were stratified by severity using the Tokyo Guidelines for acute cholangitis diagnosis. Outcomes for the validation cohort were compared with the derivation cohort (1995-2005; n = 114). Data analysis was conducted from July 1, 2015, to September 9, 2015. Main Outcomes and Measures: Death and a composite outcome of death or organ failure. Results: The median age of patients in the derivation cohort was 54 years (interquartile range, 40-65 years) and in the validation cohort was 59 years (45-67 years). Multivariate logistic regression analysis of the validation cohort confirmed white blood cell count of more than 20 000 cells/µL (odds ratio, 3.4; 95% CI, 1.2-9.5; P = .02) and total bilirubin level of more than 10 mg/dL (odds ratio, 5.4; 95% CI, 1.8-16.4; P = .003) as independent risk factors for poor outcomes. In the validation cohort, timing of endoscopic retrograde cholangiopancreatography was not significantly different between those with and without an adverse outcome, even when stratified by AC severity (moderate: median, 0.6 hours [interquartile range (IQR), 0.5-0.9] vs 1.7 hours [IQR, 0.7-18.0] and severe: median, 10.6 hours [IQR, 1.2-35.1] vs 25.5 hours [IQR, 15.5-58.5] for those with and without adverse events, respectively). Patients in the validation cohort had a shorter hospital length of stay (median, 7 days [IQR, 4-10 days] vs 9 days [IQR, 5-16 days]) and lower rate of intensive care unit admission (26% vs 82%), despite a higher rate of severe cholangitis (n = 131 [67%] vs n = 29 [25%]). There were no significant differences in the composite outcome between the validation and derivation cohorts (22 [18.6%] vs 44 [22.4%]; P = .47). Adjusted analysis demonstrated decreased mortality in the validation cohort (odds ratio, 0.3; 95% CI, 0.1-0.7; P = .01). Conclusions and Relevance: White blood cell count greater than 20 000 cells/µL and total bilirubin level greater than 10 mg/dL are independent prognostic factors for adverse outcomes in AC. Consideration should be given to include these criteria in the Tokyo Guidelines severity assessment. Timing of endoscopic retrograde cholangiopancreatography does not appear to affect clinical outcomes in these patients. Management of AC has improved with time, with an overall shorter hospital length of stay, lower rate of intensive care unit admission, and a decreased adjusted mortality, demonstrating improvements in care efficiency and delivery.