RESUMEN
OBJECTIVES: We investigated popliteal venous haemodynamics of the VenaJet Jet Impulse Technology system within a below-knee fibreglass cast. DESIGN: Randomized controlled trial. PARTICIPANTS: Twenty-four healthy participants aged 18-54 had both feet placed within the Jet Impulse Technology system and were randomised for one or other leg to be within a below-knee fibreglass cast. SETTING: Pacific Radiology, Lower Hutt, Wellington. MAIN OUTCOME MEASURES: The primary outcome variable was peak systolic velocity (cm/s) compared between legs with and without the cast at 60 min (after 10 min Jet Impulse Technology activation), using a mixed linear model and a non-inferiority bound of 4.8 cm/s. Secondary outcome variables were the difference in peak systolic velocity between the casted limb and the non-casted limb at baseline and 40 min after casting, and the difference in mean flow velocity (cm/s), vein diameter (mm), and total volume flow (L/min) between the casted limb and the non-casted limb at baseline, 40 and 60 min. RESULTS: The mean (standard deviation) peak systolic velocity was 4.6(1.5), 4.8(1.1), 28.8(16.1), and 4.3(1.2), 4.8(1.4) and 29.3(19.0) cm/s at baseline, 40 and 60 min in the casted and non-casted leg, respectively. The difference (95% confidence interval) between cast and no-cast at 60 min was -0.8 (-6.5 to 4.9) cm/s, P = 0.78. The peak systolic velocity, flow velocity and total volume flow at 40 min were not statistically significantly different from baseline for both casted and non-casted limb. CONCLUSION: In healthy volunteers, the popliteal venous haemodynamics of the Jet Impulse Technology system was similar between the legs with and without a below-knee fibreglass cast. In-cast Jet Impulse Technology may provide a non-pharmacological option for venous thromboembolism prophylaxis for lower-limb cast-immobility.
RESUMEN
OBJECTIVES: To determine the likely enrolment rate of eligible participants into a randomised controlled trial (RCT) in which a within-cast intermittent pneumatic compression device using Jet Impulse Technology (IPC/JIT) is 1 of 3 possible interventions in a RCT for the prevention of venous thromboembolism (VTE) in the clinical setting of isolated lower limb cast immobilisation. DESIGN: A prospective, open-label feasibility study of the IPC/JIT device placed within a lower limb cast. SETTING: Wellington Regional Hospital Fracture Clinic. PARTICIPANTS: Individuals aged 18-70 who presented with a lower limb injury requiring a minimum of 4â weeks below-knee cast immobilisation. INTERVENTION: Placement of an IPC/JIT device within lower limb cast. OUTCOME MEASURES: The main outcome measure was the proportion of eligible participants who participated in the feasibility study. Secondary outcome measures included adherence to device usage throughout the study, ease of application of the device and adverse events potentially associated with its use. RESULTS: The proportion of potentially eligible participants for the IPC/JIT device was only 7/142 (5%), 95% CI 2 to 9.9. Devices were used for a mean (range) of 4.1 (1.9 to 10.2) hours per day and none of 7 participants had adequate adherence to the device. 3 of the 7 participants suffered an adverse event, including 1 deep vein thrombosis, 2 dorsal foot ulcer and 1 skin maceration. CONCLUSIONS: A within-cast IPC/JIT device is unlikely to be a feasible randomisation arm for a RCT assessing possible interventions for the reduction of VTE risk in the clinical setting of lower limb injury requiring below knee cast immobilisation for a minimum of 4â weeks. TRIAL REGISTRATION NUMBER: ANZCTR 12615000192583.