Hyperbaric oxygen in patients with ischemic stroke following cardiac surgery: a retrospective observational trial.

BACKGROUND: Hyperbaric oxygenation (HBO2) involves breathing 100% oxygen under elevated ambient pressure in a hyperbaric chamber, thereby dissolving oxygen in the plasma. This results in an increase of arterial partial pressure of oxygen (pO2). Though well established in experimental studies, HBO2 treatment for ischemic stroke is still under discussion. METHODS: From 2002-2014 HBO2 (2.2 bar, 90 minutes one/day; average number per patient: 4.7) was applied in 49 consecutive patients (32 males, 17 females, mean age: 68.8 years, range 31.2 - 83.9) with acute neurological deficit following cardiac surgery (CABG 15; combined surgery 14; valve surgery 11; aneurysm repair 8; malformation 1). Patients' history including TIA or stroke and carotid artery pathology were documented. Both degree and type of neurological deficit was evaluated by a scoring system (0-4) before and after HBO2 treatment. RESULTS: Before HBO2 therapy, the average motor deficit score was 2.45 and the average speech disorder score was 0.55, as compared with an average motor deficit of 1.12 and an average speech disorder of 0.27 afterward (α=0.0001, α=0.009). The majority of patients had an overall improvement of 2 score-points after HBO2 therapy (n=23 patients). Probit analysis showed that for a 50% response/probability (LC50) of having an overall outcome of ≥2 scoring points, an estimate of 4.3 HBO2 therapy sessions is necessary. CONCLUSIONS: HBO22 therapy was associated with significant improvement in patients with acute neurological deficits due to ischemic stroke following cardiac surgery. Though this fact suggests gas embolism as the most likely cause of stroke in this collective, other underlying pathologies cannot be ruled out. Randomized studies are needed for further evaluation.

Successful Clinical Avoidance of Colorectal Anastomotic Leakage through Local Decontamination.

AIM: An anastomotic leak is an unpredictable postoperative complication during recovery from colorectal surgery that may require a re-operation. Potentially pathogenic bacteria like Pseudomonas (and Enterococcus) contribute to the pathogenesis of an anastomotic leak through their capacity to degrade collagen and to activate tissue matrix metalloprotease-9 in host intestinal tissues. The microbiome, therefore, is the key to preventing an anastomotic leak after colorectal surgery. The aim of this trial was to investigate whether perioperative selective decontamination with a new mixture of locally acting antibiotics specially designed against Pseudomonas aeruginosa and Enterococcus faecalis can reduce or even stop early symptomatic leakage. METHOD: All hospitalized patients in our University Clinic undergoing colorectal surgery with a left-sided anastomosis were included as two groups; patients in the intervention group received polymyxin B, gentamicin and vancomycin every six hours for five postoperative days and those in the control group did not receive such an intervention. An anastomotic leak was defined as a clinically obvious defect of the intestinal wall integrity at the colorectal anastomosis site (including suture) that leads to a communication between the intra- and extraluminal compartments, requiring a re-do surgery within seven postoperative days. RESULTS: Between February 2017 and May 2023, a total of 301 patients (median age of 63 years) were analyzed. An anastomotic leak was observed in 11 patients in the control group (n = 152), but in no patients in the intervention group (n = 149); this difference was highly significant. CONCLUSION: The antibiotic mixture (with polymyxin B, gentamicin and vancomycin) used for local decontamination in our study stopped the occurrence of anastomotic leaks completely. According to the definition of anastomotic leak, no further surgery was required after local perioperative decontamination.

Metabolic Cost and Mechanical Efficiency of a Novel Handle-Based Device for Wheelchair Propulsion.

OBJECTIVE: To investigate differences in metabolic cost and gross mechanical efficiency of a novel handlebased wheelchair propulsion device and to compare its performance with conventional push-rim propulsion. DESIGN: Double-group comparative study between 2 different propulsion methods. PARTICIPANTS: Eight paraplegic individuals and 10 non-disabled persons. METHODS: Participants performed the same exercise using a push-rim device and the novel handle-based device on a wheelchair- based test rig. The exercise consisted of a combined submaximal and maximal test. Power output, oxygen uptake, ventilation, respiratory exchange ratio and heart rate were recorded continuously during the tests. Analysis of variance was performed to determine the effects of group, mode and on power output. RESULTS: Submaximal exercise resulted in a higher efficiency for the novel device and significant main effects of propulsion mode on all investigated parameters, except heart rate. On the respiratory exchange ratio, a significant interaction effect was found for both mode and group. The maximal exercise resulted in a higher peak power output and lower peak heart rate during propulsion using the handle-based device. A significant main effect on mode for mean peak power output, ventilation and heart rate was also observed. CONCLUSION: Wheelchair propulsion using the handle-based device resulted in lower physical responses and higher mechanical efficiency, suggesting that this novel design may be well suited for indoor use, thereby offering an attractive alternative to pushrim wheelchairs.

In Vivo Biomechanical Assessment of a Novel Handle-Based Wheelchair Drive.

Push-rim wheelchair propulsion frequently causes severe upper limb injuries in people relying on the wheelchair for ambulation. To address this problem, we developed a novel handle-based wheelchair propulsion method that follows a cyclic motion within ergonomic joint ranges of motion. The aim of this study was to measure hand propulsion forces, joint excursions and net joint torques for this novel propulsion device and to compare its performance against traditional push-rim wheelchair propulsion. We hypothesized that under similar conditions, joint excursions of this novel handle-based device will remain within their ergonomic range and that the effectiveness of the propulsion forces will be higher, leading to lower average propulsion forces compared to push-rim propulsion and reducing the risk of injury. Eight paraplegic subjects propelled the new device at two different loads on a custom-made wheelchair-based test rig. Video motion capture and force sensors were used to monitor shoulder and wrist joint kinematics and kinetics. Shoulder and wrist loads were calculated using a modified upper-extremity Wheelchair Propulsion Model available in OpenSim. The results show that with this novel propulsion device joint excursions are within their recommended ergonomic ranges, resulting in a reduced range of motion of up to 30% at the shoulder and up to 80% at the wrist, while average resultant peak forces were reduced by up to 20% compared to push-rim propulsion. Furthermore, the lower net torques at both the shoulder and wrist demonstrate the potential of this novel propulsion system to reduce the risk of upper-extremity injuries.

A Robotic System with EMG-Triggered Functional Eletrical Stimulation for Restoring Arm Functions in Stroke Survivors.

BACKGROUND: Robotic systems combined with Functional Electrical Stimulation (FES) showed promising results on upper-limb motor recovery after stroke, but adequately-sized randomized controlled trials (RCTs) are still missing. OBJECTIVE: To evaluate whether arm training supported by RETRAINER, a passive exoskeleton integrated with electromyograph-triggered functional electrical stimulation, is superior to advanced conventional therapy (ACT) of equal intensity in the recovery of arm functions, dexterity, strength, activities of daily living, and quality of life after stroke. METHODS: A single-blind RCT recruiting 72 patients was conducted. Patients, randomly allocated to 2 groups, were trained for 9 weeks, 3 times per week: the experimental group performed task-oriented exercises assisted by RETRAINER for 30 minutes plus ACT (60 minutes), whereas the control group performed only ACT (90 minutes). Patients were assessed before, soon after, and 1 month after the end of the intervention. Outcome measures were as follows: Action Research Arm Test (ARAT), Motricity Index, Motor Activity Log, Box and Blocks Test (BBT), Stroke Specific Quality of Life Scale (SSQoL), and Muscle Research Council. RESULTS: All outcomes but SSQoL significantly improved over time in both groups (P < .001); a significant interaction effect in favor of the experimental group was found for ARAT and BBT. ARAT showed a between-group change of 11.5 points (P = .010) at the end of the intervention, which increased to 13.6 points 1 month after. Patients considered RETRAINER moderately usable (System Usability Score of 61.5 ± 22.8). CONCLUSIONS: Hybrid robotic systems, allowing to perform personalized, intensive, and task-oriented training, with an enriched sensory feedback, was superior to ACT in improving arm functions and dexterity after stroke.

Measurement of cardiac output and pulmonary transit time for assessment of pulmonary vascular resistance in domestic piglets.

The degree of elevated pulmonary vascular resistance (PVR) is a crucial clinical parameter. Cardiac output (CO) and pulmonary transit time (PTT) can be ascertained by a number of radiological methods. A close functional relationship between CO, PTT and PVR would facilitate non-invasive PVR measurements. One-hundred and fifty-one measurements were made in six piglets. Pressures in the pulmonary and systemic circulation were measured invasively. Cardic output was determined by the use of a Doppler flow probe around the truncus pulmonalis. Temperature sensors were placed in the pulmonary truncus and left atrium. Elevated PVR was produced by repeated air embolism. After injection of ice-cold saline, the time span between the minimal temperature in the truncus pulmonalis and the left atrium was taken as PTT. The CO and PTT were inserted into a new formula derived from the Hagen-Poiseuille law for the calculation of the PVR model. Numerical constants of the formula were calculated by the robust method of minimization. The PVR values, as calculated from invasively measured mean pulmonary artery pressure, mean left atrial pressure and CO, served as reference. In the six piglets, the PVR model and PVR reference showed a strong linear correlation with r = 0.923. The Bland-Altman plot revealed a standard deviation of -0.64/+0.67 Wood units. Cardiac output, PTT and PVR showed a close functional relationship. With a correction for blood viscosity and body size, this relationship could be used for non-invasive clinical measurements of PVR.

Psychological and systemic stress reactions of patients during hyperthermia treatments.

PURPOSE: This study evaluated psychological stress reactions during hyperthermia (HT) treatments and compared them to systemic stress reactions. MATERIALS AND METHODS: 27 patients with malignant disease were treated with superficial or regional hyperthermia. Cortisol and the catecholamines adrenaline and noradrenaline in venous blood were used as markers of psychological stress. The anxiety proneness of the patients was evaluated with a trait-anxiety inventory. Blood pressure and heart rate were markers of systemic stress. Patients were first grouped by superficial or regional treatment and then into two subgroups: anxious and non-anxious patients. RESULTS: The time course of the cortisol concentration of the superficial group showed a slight but significant decrease and that of the regional group an increase. The cortisol concentration of the regional group was sometimes slightly but significantly higher than in the superficial group, and in the group of anxious patients higher than in the group of non-anxious patients. The changes in time courses and differences in groups were not as pronounced for the catecholamine concentrations. Heart rate and blood pressure showed a significant increase only in the regional group, and there was no significant difference between the regional and the superficial groups. None of the variables showed a significant difference between the initial and the subsequent treatments; all lay well within the normal physiological range. CONCLUSIONS: These standard hyperthermia treatments are not excessively stressful, either systemically or psychologically. The different behaviours of the variables confirm that it makes sense to consider systemic stress as well as psychological reactions.

Forward dynamic optimization of handle path and muscle activity for handle based isokinetic wheelchair propulsion: A simulation study.

Push-rim wheelchair propulsion is biomechanically inefficient and physiologically stressful to the musculoskeletal structure of human body. This study focuses to obtain a new, optimized propulsion shape for wheelchair users, which is within the ergonomic ranges of joint motion, thus reducing the probability of injuries. To identify the propulsion movement, forward dynamic optimization was performed on a 3D human musculoskeletal model linked to a handle based propulsion mechanism, having shape and muscle excitations as optimization variables. The optimization resulted in a handle path shape with a circularity ratio of 0.95, and produced a net propulsion power of 34.7 watts for an isokinetic propulsion cycle at 50 rpm. Compared to push-rim propulsion, the compact design of the new propulsion mechanism along with the ergonomically optimized propulsion shape may help to reduce the risk of injuries and thus improve the quality of life for wheelchair users.

A preliminary muscle activity analysis: Handle based and push-rim wheelchair propulsion.

Approximately ninety percent of the wheelchair users worldwide prefer the conventional push rim mode of propulsion for daily mobility and rehabilitation. Even though push-rim wheelchairs help to promote a healthy life style, the high muscular demand and the non-continuous push motions can lead to serious upper extremity injuries. In this study, muscle EMG data of ten healthy subjects were recorded for a newly introduced handle based propulsion mechanism (HBP) and compared to conventional push-rim propulsion at two workloads, 25 W and 35 W respectively. The results for the mean peak muscle activations at both workloads demonstrate that push-rim propulsion leads to higher peak muscle activity compared to HBP at a similar wheelchair forward velocity of 1.11 m/s. The generation of these high peak muscle activations with increasing loads in push-rim propulsion over time can lead to overuse injuries. Overall, the use of the HBP mechanism is less straining to the muscles and may reduce fatigue during prolonged propulsion.

A Hybrid Robotic System for Arm Training of Stroke Survivors: Concept and First Evaluation.

OBJECTIVE: To develop and evaluate a hybrid robotic system for arm recovery after stroke, combining ElectroMyoGraphic (EMG)-triggered functional electrical stimulation (FES) with a passive exoskeleton for upper limb suspension. METHODS: The system was used in a structured exercise program resembling activities of daily life. Exercises execution was continuously controlled using angle sensor data and radio-frequency identification technology. The training program consisted of 27 sessions lasting 30 min each. Seven post-acute stroke patients were recruited from two clinical sites. The efficacy of the system was evaluated in terms of action research arm test, motricity index, motor activity log, and box & blocks tests. Furthermore, kinematics-based and EMG-based outcome measures were derived directly from data collected during training sessions. RESULTS: All patients showed an improvement of motor functions at the end of the training program. After training, the exercises were in most cases executed faster, smoother, and with an increased range of motion. Subjects were able to trigger FES, but in some cases, they did not maintain the voluntary effort during task execution. All subjects but one considered the system usable. CONCLUSION: The preliminary results showed that the system can be used in a clinical environment with positive effects on arm functional recovery. However, only the final results of the currently ongoing clinical trial will unveil the system's full potential. SIGNIFICANCE: The presented hybrid robotic system is highly customizable, allows to monitor the daily performance, requires low supervision of the therapist, and might have the potential to enhance arm recovery after stroke.

Wrist Kinematics and Kinetics during Wheelchair Propulsion with a Novel Handle-based Propulsion Mechanism.

Wheelchairs are important for daily mobility and recreation of the elderly and physically challenged individuals. The non-ergonomical propulsion design of wheelchairs frequently causes injuries to the upper extremities, especially in the wrist region. In this study, the joint kinematics and kinetics of the wrist joint was analyzed on subjects propelling a novel handle based wheelchair propulsion unit at 1.2m/s speed (20W and 40W respectively). The joint kinematics and the joint moments of the wrist were determined using a 3D musculoskeletal model. The mean values of joint ranges and torques during propulsion at the mentioned speeds were lower when compared to standard wheelchair propulsion with the push-rim, making the novel propulsion mechanism with its compact design an interesting alternative for wheelchair users that might help to avoid or reduce joint injuries.

Analysis of Social Determinants of Health and Disability Scores in Leprosy-Affected Persons in Salem, Tamil Nadu, India.

A consistent relationship has been found between leprosy and inequities in social determinants of health. It, however, remains unclear which aspect of these social determinants contributes most to the risk of infection, and even less clear are the risk factors for the development of leprosy-related disabilities. The objective of this study was to elicit the differential impact of social determinants of health in leprosy-affected persons, and determine whether structural inequities in accessibility to societal resources and lower socioeconomic parameters correlated with higher severity of disabilities. This analysis was based on a sampled population affected by leprosy in Salem, Tamil Nadu, India. Persons enrolled in the study were covered by a nongovernmental lifelong care program, had completed a multidrug therapy for leprosy and/or were slit-skin-smear negative, and showed Grade 1 or higher disabilities due to leprosy. Multiple stepwise linear regression analysis was performed. The Eyes-Hands-Feet (EHF) score was the outcome variable, and gender, age, time after release from treatment, monthly income, and living space were explanatory variables. There were 123 participants, comprised of 41 (33.33%) women and 82 (66.67%) men. All study participants belonged to India's Backward classes; 81.30% were illiterate and the average monthly income was 1252 Indian rupee (INR) (US$19.08 or €17.16). The average EHF score was 7.016 (95% CI, 6.595 to 7.437). Stepwise multiple linear regression analysis built a significant model, where F(2, 120) = 13.960, p ≤ 0.001, effect size (Cohen's f2) = 0.81, explaining 18.9% of the variance in EHF scores (R² = 0.189). Significant predictors of a higher EHF score in persons affected by leprosy were found to be higher age (beta = 0.340, 95% CI, 0.039 to 0.111, p < 0.001), as well as less living space (beta = -0.276, 95% CI, -0.041 to -0.011, p = 0.001). Our results suggest that inequalities in social determinants of health correspond to higher disability scores, which indicates that poor living standards are a common phenomenon in those living with leprosy-related disabilities. Further research is needed to dissect the exact development of impairments after release from treatment (RFT) in order to take targeted actions against disability deterioration.

Reference values for plasma concentrations of asymmetrical dimethylarginine (ADMA) and other arginine metabolites in men after validation of a chromatographic method.

BACKGROUND: Owing to the growing number of reports in the literature on ADMA as a possibly useful marker of endothelial health, its use in the clinical laboratory is of increasing interest. Age dependency and the small, but statistically significant differences between healthy subjects and disease groups are difficult to interpret. Additionally, levels of ADMA in comparable patient groups of different studies vary widely, even when similar methods have been used. METHODS: After analytical evaluation of a chromatographic method according to international guidelines, we analysed asymmetrical (ADMA) and symmetrical dimethyl arginine (SDMA), homo-arginine and arginine in EDTA plasma of 292 healthy males aged 20 to 75 years (y) who had passed strict inclusion/exclusion criteria. For statistical analysis, 4 age groups were formed. Group differences were identified with the non-parametric Kruskal-Wallis test. RESULTS: Calibration curves were linear throughout the selected ranges; the standard deviation for the regression line, recovery, imprecision, and accuracy results were all highly satisfactory. The reference ranges of ADMA for the 4 age groups are presented as age (mean+/-SD of age group, y); number of subjects; median, 2.5th-97.5th percentile: group <35 y: 26.7+/-4.0 y; n=78; 0.58, 0.43-0.69 micromol/L; group 35-49 y: 41.6+/-4.0 y; n=93; 0.59, 0.45-0.73 micromol/L; group 50-65 y: 57.5+/-4.2 y; n=82; 0.61, 0.46-0.78 micromol/L; and group >65 y: 69.6+/-3.3 y; n=39; 0.64, 0.54-0.79 micromol/L. CONCLUSIONS: Only highly precise methods are able to detect small differences between groups. The application of an evaluated method to a well defined group of healthy subjects should provide a basis for comparison of ADMA concentrations in different patient populations of future studies.

BRIDGE - Behavioural reaching interfaces during daily antigravity activities through upper limb exoskeleton: Preliminary results.

People with neuromuscular diseases such as muscular dystrophy experience a distributed and evolutive weakness in the whole body. Recent technological developments have changed the daily life of disabled people strongly improving the perceived quality of life, mostly concentrating on powered wheelchairs, so to assure autonomous mobility and respiratory assistance, essential for survival. The key concept of the BRIDGE project is to contrast the everyday experience of losing functions by providing them of a system able to exploit the best their own residual capabilities in arm movements so to keep them functional and autonomous as much as possible. BRIDGE is composed by a light, wearable and powered five degrees of freedom upper limb exoskeleton under the direct control of the user through a joystick or gaze control. An inverse kinematic model allows to determine joints position so to track patient desired hand position. BRIDGE prototype has been successfully tested in simulation environment, and by a small group of healthy volunteers. Preliminary results show a good tracking performance of the implemented control scheme. The interaction procedure was easy to understand, and the interaction with the system was successful.

Pulmonary valve replacement with mechanical prostheses in re-do Fallot patients.

In this prospective clinical study, we have compared 17 patients with tetralogy of Fallot (TOF) who received mechanical valve substitutes and had concomitant additional right ventricular (RV) volume reduction plasty (aRVVRP, group 1) with seven patients who underwent solitary re-do pulmonary valve replacements (PVR, group 2). All patients were evaluated by magnetic resonance imaging (MRI) two months pre- and four to six months postoperatively for assessment of ventricular geometry. At a mean follow-up of 31.9 months, the RV ejection fraction improved from 39.1 to 48.3% in group 1 vs. from 40.1 to 49% in group 2 (P<0.001), and RV indexed end-diastolic volume decreased from 174.8 to 119.9 ml/m(2) (group 1) vs. from 142.4 to 99.6 ml/m(2) (group 2, P<0.001). Indexed RV myocardial mass decreased from 52.3 to 38.7 g/m(2) in group 1 vs. 46.9 to 39.1 g/m(2) in group 2 (P<0.001). Follow-up revealed no mortality and distinct improvements in RV geometry, recommending mechanical prostheses as suitable alternatives for PVR. Selection criteria for this solution should consider multiple previous reoperations and assured patient compliance in terms of current anticoagulant usage and self-testing. aRVVRP could serve as an adjunct in re-dos of TOF surgery indicated by RV outflow tract dysfunction due to akinetic fibrous areas.

Plastic surgeons and the Internet: results of a worldwide survey.

To obtain information on the use of the Internet, 3,139 survey forms were sent out to plastic surgeons throughout the world. More than 90% of the 565 respondents have access to the Internet and 85.5% use electronic mail for professional matters. They use the World Wide Web to search the literature, to read scientific articles, and to obtain information on congresses. A substantial proportion of the contributors have a positive attitude toward virtual congresses on the Internet and most would welcome a newsgroup dedicated to plastic surgery. Perceived apprehensions include secure transmission of sensitive data, slow data transmission, and the lack of structure and of an authority to control the contents of the Internet. Virtual congresses and a newsgroup on plastic surgery seem to be worthwhile future goals. Some problems pointed out in this survey have already been solved, at least partially, and possible solutions for the rest are discussed.