Breath-synchronized electrical stimulation of the expiratory muscles in mechanically ventilated patients: a randomized controlled feasibility study and pooled analysis.

BACKGROUND: Expiratory muscle weakness leads to difficult ventilator weaning. Maintaining their activity with functional electrical stimulation (FES) may improve outcome. We studied feasibility of breath-synchronized expiratory population muscle FES in a mixed ICU population ("Holland study") and pooled data with our previous work ("Australian study") to estimate potential clinical effects in a larger group. METHODS: Holland: Patients with a contractile response to FES received active or sham expiratory muscle FES (30 min, twice daily, 5 days/week until weaned). Main endpoints were feasibility (e.g., patient recruitment, treatment compliance, stimulation intensity) and safety. Pooled: Data on respiratory muscle thickness and ventilation duration from the Holland and Australian studies were combined (N = 40) in order to estimate potential effect size. Plasma cytokines (day 0, 3) were analyzed to study the effects of FES on systemic inflammation. RESULTS: Holland: A total of 272 sessions were performed (active/sham: 169/103) in 20 patients (N = active/sham: 10/10) with a total treatment compliance rate of 91.1%. No FES-related serious adverse events were reported. Pooled: On day 3, there was a between-group difference (N = active/sham: 7/12) in total abdominal expiratory muscle thickness favoring the active group [treatment difference (95% confidence interval); 2.25 (0.34, 4.16) mm, P = 0.02] but not on day 5. Plasma cytokine levels indicated that early FES did not induce systemic inflammation. Using a survival analysis approach for the total study population, median ventilation duration and ICU length of stay were 10 versus 52 (P = 0.07), and 12 versus 54 (P = 0.03) days for the active versus sham group. Median ventilation duration of patients that were successfully extubated was 8.5 [5.6-12.2] versus 10.5 [5.3-25.6] days (P = 0.60) for the active (N = 16) versus sham (N = 10) group, and median ICU length of stay was 10.5 [8.0-14.5] versus 14.0 [9.0-19.5] days (P = 0.36) for those active (N = 16) versus sham (N = 8) patients that were extubated and discharged alive from the ICU. During ICU stay, 3/20 patients died in the active group versus 8/20 in the sham group (P = 0.16). CONCLUSION: Expiratory muscle FES is feasible in selected ICU patients and might be a promising technique within a respiratory muscle-protective ventilation strategy. The next step is to study the effects on weaning and ventilator liberation outcome. TRIAL REGISTRATION: ClinicalTrials.gov, ID NCT03453944. Registered 05 March 2018-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03453944 .

Abdominal functional electrical stimulation to assist ventilator weaning in critical illness: a double-blinded, randomised, sham-controlled pilot study.

BACKGROUND: For every day a person is dependent on mechanical ventilation, respiratory and cardiac complications increase, quality of life decreases and costs increase by > $USD 1500. Interventions that improve respiratory muscle function during mechanical ventilation can reduce ventilation duration. The aim of this pilot study was to assess the feasibility of employing an abdominal functional electrical stimulation (abdominal FES) training program with critically ill mechanically ventilated patients. We also investigated the effect of abdominal FES on respiratory muscle atrophy, mechanical ventilation duration and intensive care unit (ICU) length of stay. METHODS: Twenty critically ill mechanically ventilated participants were recruited over a 6-month period from one metropolitan teaching hospital. They were randomly assigned to receive active or sham (control) abdominal FES for 30 min, twice per day, 5 days per week, until ICU discharge. Feasibility was assessed through participant compliance to stimulation sessions. Abdominal and diaphragm muscle thickness were measured using ultrasound 3 times in the first week, and weekly thereafter by a blinded assessor. Respiratory function was recorded when the participant could first breathe independently and at ICU discharge, with ventilation duration and ICU length of stay also recorded at ICU discharge by a blinded assessor. RESULTS: Fourteen of 20 participants survived to ICU discharge (8, intervention; 6, control). One control was transferred before extubation, while one withdrew consent and one was withdrawn for staff safety after extubation. Median compliance to stimulation sessions was 92.1% (IQR 5.77%) in the intervention group, and 97.2% (IQR 7.40%) in the control group (p = 0.384). While this pilot study is not adequately powered to make an accurate statistical conclusion, there appeared to be no between-group thickness changes of the rectus abdominis (p = 0.099 at day 3), diaphragm (p = 0.652 at day 3) or combined lateral abdominal muscles (p = 0.074 at day 3). However, ICU length of stay (p = 0.011) and ventilation duration (p = 0.039) appeared to be shorter in the intervention compared to the control group. CONCLUSIONS: Our compliance rates demonstrate the feasibility of using abdominal FES with critically ill mechanically ventilated patients. While abdominal FES did not lead to differences in abdominal muscle or diaphragm thickness, it may be an effective method to reduce ventilation duration and ICU length of stay in this patient group. A fully powered study into this effect is warranted. TRIAL REGISTRATION: The Australian New Zealand Clinical Trials Registry, ACTRN12617001180303. Registered 9 August 2017.

Sense of belonging to specific communities and depressive symptoms among Australian gay men.

Sense of belonging to the general and broader gay communities has been shown to be beneficial for gay men's mental health. This research investigated the interrelations between sense of belonging to three forms of gay community (the broader gay community, gay groups, and gay friends), sense of belonging to the general community, and depressive symptoms by examining a path model. A community sample of 177 gay men, aged 18 to 79 years, completed the Sense of Belonging Instrument-Psychological subscale, the Centre for Epidemiological Studies-Depression Scale, and the Sense of Belonging within Gay Communities Scale. The model provided excellent fit to the data in which sense of belonging to the general community mediated the relationships between a sense of belonging to gay groups and with gay friends and depressive symptoms. Results imply that enhancing gay men's sense of belonging to gay groups and with gay friends is likely to be associated with fewer depressive symptoms, by virtue of their enhanced sense of belonging to the general community.

Changes in pulmonary function measures following a passive abdominal functional electrical stimulation training program.

OBJECTIVE: To demonstrate the effect of a passive abdominal functional electrical stimulation (AFES) training program on unassisted respiratory measures in tetraplegia. DESIGN: Longitudinal feasibility study. SETTING: National spinal injuries unit in a university teaching hospital. PARTICIPANTS: Twelve patients with tetraplegic spinal cord injury, who could breathe independently, with reduced vital capacity and no visible abdominal movement. INTERVENTION: Three weeks of abdominal muscle conditioning using transcutaneous AFES. MAIN OUTCOME MEASURES: Forced vital capacity (FVC), forced exhaled volume in 1 second (FEV1), peak expiratory flow rate (PEF), and maximum exhaled pressure (MEP). RESULTS: Mean (SD) FVC increased by 0.36 l (0.23) during training (P = 0.0027). Mean (SD) FEV1 and PEF tended to increase by 0.18 l (0.16) and 0.39 l/seconds (0.35), respectively, but this was not significant. No significant change was found in the outcome measures during a 1-week pre-training control phase and during a 3-week post-training phase. CONCLUSIONS: The increase in FVC over the training period and the absence of change before or after training suggest that passive abdominal FES training can be used for respiratory rehabilitation in tetraplegia.

Housing type and depressive symptoms among older adults: a test of sense of belonging as a mediating and moderating variable.

OBJECTIVES: Higher levels of depression have been documented among older adults who reside in an assisted living facility, compared with those who remain in their own homes. The aims of the current study were to test whether the relationship between housing type and depressive symptoms was mediated by a sense of belonging and whether housing type and sense of belonging interact to influence the depressive symptoms among older adults (moderation model). METHOD: A sample of 257 older adults who lived in their own homes and 166 older adults who lived in an assisted living facility completed the psychological subscale of the Sense of Belonging Instrument and the Center for Epidemiologic Studies Depression Scale. RESULTS: Results showed that a sense of belonging partially mediated the relationship between housing type and depressive symptoms, such that living in a nursing home was associated with lower levels of belonging, and lower levels of belonging were, in turn, associated with higher levels of depressive symptoms. Residing in an assisted living facility was associated with depressive symptoms at low and average levels of belonging. CONCLUSION: Results highlight the need for more research on the role of sense of belonging as an influencing factor on depressive symptoms among institutionalised older adults for both theoretical and treatment goals.

An SSVEP-based brain-computer interface for the control of functional electrical stimulation.

A brain-computer interface (BCI) based on steady-state visual-evoked potentials (SSVEPs) is combined with a functional electrical stimulation (FES) system to allow the user to control stimulation settings and parameters. The system requires four flickering lights of distinct frequencies that are used to form a menu-based interface, enabling the user to interact with the FES system. The approach was evaluated in 12 neurologically intact subjects to change the parameters and operating mode of an abdominal stimulation system for respiratory assistance. No major influence of the FES on the raw EEG signal could be observed. In tests with a self-paced task, a mean accuracy of more than 90% was achieved, with detection times of approximately 7.7 s and an average information transfer rate of 12.5 bits/min. There was no significant dependency of the accuracy or time of detection on the FES stimulation intensity. The results indicate that the system could be used to control FES-based neuroprostheses with a high degree of accuracy and robustness.