Objective: BIONs™ BIOnic Neurons are injectable, wireless microstimulators that make chronic BION Active Seating BAS possible for pressure ulcer prevention PUP. Neuromuscular electrical stimulation NMES produces skeletal motion and activates trophic factors, counteracting three major etiological mechanisms leading to pressure ulcers PUs: immobility, soft-tissue atrophy, and ischemia. Companion papers I and II reviewed prior experience with NMES for PUP, and analyzed the biomechanical considerations, respectively. This paper presents a treatment strategy derived from this analysis, and the clinical results of the first three cases. Methods: Two BIONs implanted one on inferior gluteal nerve to gluteus maximus GM, and other on sciatic nerve to hamstrings HS, in 3 spinal cord injured SCI subjects already undergoing gluteal rotation flaps for PUs. BAS using HS when seated, and BION Conditioning BC via GM+HS when non-weightbearing. Follow-up: 1 yr, including 6 mo. treatment window interface pressure mapping; muscle perfusion scans; MRI, X-ray volume assessments. Results: Successfully implanted and activated both desired muscle groups, selectively, in all. No PU recurrences or wound complications. Two subjects completed protocol. Mean results: Interface: contact pressure -10%; maximum pressure -20%; peak pressure area -15%. Vascularity: GM +20%, HS +110%. Perfusion: GM +70%, HS +440%. Muscle volume: GM +14%, HS +31%. Buttock soft-tissue padding: +49%. 1 BION failed; 1 BION rotated under GM. Conclusions: Promising proof-of-concept data supporting the feasibility of implanted microstimulators to achieve sufficiently strong and selective activation of target muscles for PUP. Ultimate goal is prophylactic deployment through bilateral, nonsurgical injection of BIONs in chronically immobile patients.

/pdf/preventing-ischial-pressure-ulcers-iii-clinical-pilot-study-2q4b6t6g0r.pdf

Preventing ischial pressure ulcers: III. clinical pilot study of chronic neuromuscular electrical stimulation

Objective: Pressure ulcers PUs are common and debilitating wounds that arise when immobilized patients cannot shift their weight. Treatment is expensive and recurrence rates are high. Pathophysiological mechanisms include reduced bulk and perfusion of chronically atrophic muscles as well as prolonged occlusion of blood flow to soft tissues from lack of voluntary postural shifting of body weight. This has suggested that PUs might be prevented by reanimating the paralyzed muscles using neuromuscular electrical stimulation NMES. A review of the published literature over the past 2 decades is detailed. Outcomes: Historically gluteus maximus GM has been an important target for NMES, but results have been difficult to interpret and suitable technology has been lacking. Conclusions: NMES of the buttock muscles appears to be valuable in terms of its trophic effects, improving vascularity and soft tissue bulk. It remains unclear, however, whether GM can actually achieve sufficient unloading of normal forces to permit blood flow in the capillary beds of the skin and muscle. Analysis of the skeletal biomechanics is required to assess the relative value of GM vs. hamstring HS hip extensors in this regard.

/pdf/preventing-ischial-pressure-ulcers-i-review-of-neuromuscular-4fiigvmnni.pdf

Preventing ischial pressure ulcers: I. Review of neuromuscular electrical stimulation

Abstract Background Pressure injuries (PIs), especially in the sacral region are frequent, costly, and increase morbidity and mortality of patients in an intensive care unit (ICU). These injuries can occur as a result of prolonged pressure and/or shear forces. Neuromuscular electrical stimulation (NMES) can increase muscle mass and improve local circulation, potentially reducing the incidence of PI. Methods We performed a randomized controlled trial to assess the efficacy and safety of NMES in preventing PI in critically ill patients. We included patients with a period of less than 48 h in the ICU, aged ≥ 18 years. Participants were randomly selected (1:1 ratio) to receive NMES and usual care (NMES group) or only usual care (control group—CG) until discharge, death, or onset of a PI. To assess the effectiveness of NMES, we calculated the relative risk (RR) and number needed to treat (NNT). We assessed the muscle thickness of the gluteus maximus by ultrasonography. To assess safety, we analyzed the effects of NMES on vital signs and checked for the presence of skin burns in the stimulated areas. Clinical outcomes were assessed by time on mechanical ventilation, ICU mortality rate, and length of stay in the ICU. Results We enrolled 149 participants, 76 in the NMES group. PIs were present in 26 (35.6%) patients in the CG and 4 (5.3%) in the NMES group ( p ˂ 0.001). The NMES group had an RR = 0.15 (95% CI 0.05–0.40) to develop a PI, NNT = 3.3 (95% CI 2.3–5.9). Moreover, the NMES group presented a shorter length of stay in the ICU: Δ = − 1.8 ± 1.2 days, p = 0.04. There was no significant difference in gluteus maximus thickness between groups (CG: Δ = − 0.37 ± 1.2 cm vs. NMES group: Δ = 0 ± 0.98 cm, p = 0.33). NMES did not promote deleterious changes in vital signs and we did not detect skin burns. Conclusions NMES is an effective and safe therapy for the prevention of PI in critically ill patients and may reduce length of stay in the ICU. Trial registration RBR-8nt9m4. Registered prospectively on July 20th, 2018, https://ensaiosclinicos.gov.br/rg/RBR-8nt9m4 

https://annalsofintensivecare.springeropen.com/counter/pdf/10.1186/s13613-022-01029-1

Efficacy and safety of neuromuscular electrical stimulation in the prevention of pressure injuries in critically ill patients: a randomized controlled trial

Background: Pressure ulcers PUs are common and debilitating wounds that arise when immobilized patients cannot shift their weight. Neuromuscular Electrical Stimulation NMES has been investigated for Pressure Ulcer Prevention PUP for over 20 years. Historically gluteus maximus GM has been considered an important actuator in attempting to redistribute seated pressures through NMES. Methods: Analysis of skeletal biomechanics to quantify the value of GM relative to hamstring hip extensors HS, using muscle moment models based on torques and rigid body mass estimates from the literature. Surface stimulation experiments n = 10 + 1, non-paralyzed to validate model and identify promising stimulation sites and treatment strategies that would approximate healthy biomechanics. Results: Literature values and Rigid Body Analysis estimate: ~63 Nm extensor torque requirement calculated for complete ipsilateral unloading of the buttocks. Muscle Moment Analysis: GM can provide 70% of total hip extensor torque when walking vs. 18% when seated. HS can provide 100 Nm hip extension torque when seated, exceeding 63 Nm requirement. Surface Stimulation: ipsilateral seated interface pressure mean -26% during HS stimulation vs. +16% with GM; peak pressure area -94% HS vs. +213% GM. Conclusions: GM activation reduces disuse atrophy and improves circulation, but appears neither required, nor desired, for unloading when seated. HS stimulation alone should be capable of sufficient unloading. This new proposed approach is explored clinically in companion paper III.

/pdf/preventing-ischial-pressure-ulcers-ii-biomechanics-3mm0jxlyy6.pdf

Nga Ting Wong

Papers

Preventing ischial pressure ulcers: II. Biomechanics