Alteration of Ligamento-Muscular Reflex Patterns After Cutaneous and Periarticular Desensitization of the Basal Thumb Joint: An Electromyographic Study.

PURPOSE: Stimulation of the dorsoradial ligament (DRL) of the first carpometacarpal joint (CMC-1) has shown a ligamento-muscular reflex pathway between the DRL and CMC-1 stabilizing muscles in healthy volunteers. However, it remains unclear how this ligamento-muscular reflex pattern is altered after anesthetizing sensory skin receptors and administering a further periarticular block around the CMC-1 joint, which may influence the dynamic aspects of joint stability. METHODS: Ligamento-muscular reflexes were obtained from the extensor pollicis longus, abductor pollicis longus, abductor pollicis brevis, and the first dorsal interosseous muscles in 10 healthy participants after establishing superficial anesthesia of the skin around the CMC-1. The DRL was stimulated with a fine wire electrode while EMG activities were recorded during isometric tip, key, and palmar pinch. The measurements were repeated after an additional periarticular CMC-1 block using 5 ml of 1% lidocaine. Average EMG values were analyzed to compare the prestimulus and poststimulus activity. RESULTS: Statistically significant changes in poststimulus EMG activity were observed in all 4 muscles and all 3 tested thumb positions. A markedly reduced activity in all 4 muscles was observed in the palmar position, followed by the tip and key pinch positions. Almost no reactions were observed in the first 20 ms poststimulus for all muscles in all positions. CONCLUSIONS: Superficial skin anesthesia and an additional periarticular CMC-1 block anesthesia resulted in a reduced ligamento-muscular reflex pattern in all 4 muscles. CLINICAL RELEVANCE: Ligamento-muscular reflexes play an important role in dynamic CMC-1 joint stability. The elimination of early reactions, those considered joint-protective reflexes, is a potential risk factor for developing osteoarthritis or injury because it results in an inability to adequately protect and stabilize the joint in sudden movements.

Design for risk control: the role of usability engineering in the management of use-related risks.

The majority of medical device incident reports can primarily be attributed to use error. Greater attention to human factors and usability during development of a medical device could improve this situation. However, recent studies have shown that companies do not find the application of a sound usability engineering process according to international standards a simple task. The purpose of this collaborative research project between a medical device company, two universities and a university hospital was to study the practical application of the International Standard for Application of Usability Engineering to Medical Devices, IEC 62366, by means of a case study in industrial practice. This paper describes the user studies in the case and reveals the factors important to success. Also, the paper demonstrates how to apply an iterative usability engineering process within a linear product development process in industry. Management support and careful planning of resources and activities proved essential. To control use-related risks, the usability engineer should 'design for risk control' in a structured manner, while the risk manager should remain responsible for acceptable levels of residual risk. The paper concludes with recommendations for the improvement of IEC 62366 and ISO 14971, the standard for the risk management of medical devices.

Obstructive sleep apnea syndrome is associated with overactive bladder and urgency incontinence in men.

STUDY OBJECTIVE: To investigate the incidence of overactive bladder (OAB) and urgency incontinence (UI) in men with obstructive sleep apnea syndrome (OSAS). DESIGN: Prospective questionnaire study SETTING: Saarland University Hospital PATIENTS: All male patients who underwent full-night in-laboratory polysomnography between November 2006 and April 2007. INTERVENTIONS: Overactive bladder symptom score (OABSS) and International Consultation on Incontinence Questionnaire, Short-Form (ICIQ-SF). MEASUREMENTS AND RESULTS: OSAS severity was assessed according to the apnea-hypopnea-index (AHI). Return rate of questionnaires was 100% (n=100). Patients with upper airway resistance syndrome (UARS) served as controls. Evaluation of OABSS revealed that patients with moderate and severe OSAS presented with a significantly higher incidence of symptoms of OAB than patients with mild OSAS and UARS (P<0.05). Further, the ICIQ-SF revealed a higher occurrence of UI in patients with severe OSAS than in those with mild OSAS and UARS (P<.05). CONCLUSIONS: Increasing severity of OSAS appears to be associated with an increasing occurrence of overactive bladder and urgency incontinence in men. This relationship may have clinical implications for the treatment of affected patients.

Impact of the post-anesthetic care unit opening hours on fast-track success in cardiac surgery.

BACKGROUND: Fast-track (FT) treatment in cardiac anesthesia is a state-of-the-art technique. The aim of our study was to compare FT treatment in a post-anesthetic care unit (PACU) with limited opening hours with a PACU opened for unlimited hours. Primary endpoints were extubation time (ET), length of stay (LOS) in PACU and LOS in intermediate care unit (IMC). Secondary endpoints were FT success/failure, hospital LOS, re-intubation and in hospital mortality. METHODS: At our institution, FT is usually managed in a PACU with limited opening hours from 10 a.m. to 10 p.m., Monday to Friday (PACU12). Due to reconstruction work in 2011, this PACU was open 24 hours a day, Monday to Saturday (PACU24). We retrospectively compared patients admitted to PACU24 during 2011 (January to December) and patients admitted to PACU12 during 2013 (January to December). RESULTS: A total of 2174 patients were primarily included in the study, 319 of them had to be excluded. Primary endpoints in PACU12 compared to PACU24 were significantly shorter: median ET (2.0 [95% confidence interval: 1.4-2.8] vs. 3.3 [95% CI: 2.2-5.0] hours), median LOS in PACU (4.8 [95% CI: 4.0-5.9] vs. 21.2 [95% CI: 18.3-23.5] hours) and median LOS in IMC (24 [95% CI: 18-64] vs. 38 [95% CI: 22-77] hours). FT success was significantly higher in PACU12 compared to PACU24 (75.3% vs. 39.6%). The in-hospital mortality and re-intubation rate were not significantly different. CONCLUSIONS: FT treatment in a PACU with limited opening hours leads to more effective treatment for patients regarding extubation time and LOS in IMC than in a PACU with limited opening hours, without compromising safety.