Allen V. Prettyman

Influence of increased plasma osmolality on sympathetic outflow during apnea

Animal models have shown that peripheral chemoreceptors alter their firing patterns in response to changes in plasma osmolality, which, in turn, may modulate sympathetic outflow. The purpose of this study was to test the hypothesis that increases in plasma osmolality augment muscle sympathetic nerve activity (MSNA) responses to chemoreceptor activation. MSNA was recorded from the peroneal nerve (microneurography) during a 23-min intravenous hypertonic saline infusion (3% NaCl; HSI). Chemoreceptor activation was elicited by voluntary end-expiratory apnea. MSNA responses to end-expiratory apnea were calculated as the absolute increase from the preceding baseline period. Plasma osmolality significantly increased from pre- to post-HSI (284 ± 1 to 290 ± 1 mOsm/kg H(2)O; P < 0.01). There was a significant overall effect of osmolality on sympathetic activity (P < 0.01). Duration of the voluntary end-expiratory apnea was not different after HSI (pre = 40 ± 5 s; post = 41 ± 4 s). MSNA responses to end-expiratory apnea were not different after HSI, expressed as an absolute change in burst frequency (n = 11; pre = 8 ± 2; post = 11 ± 1 burst/min) and as a percent increase in total activity (pre = 51 ± 4% AU; post = 53 ± 4% AU). A second group of subjects (n = 8) participated in 23-min volume/time-control intravenous isotonic saline infusions (0.9% NaCl). Isotonic saline volume-control infusions yielded no change in plasma osmolality or MSNA at rest. Furthermore, MSNA responses to apnea following isotonic saline infusion were not different. In summary, elevated plasma osmolality increased MSNA at rest and during apnea, but contrary to the hypothesis, MSNA responsiveness to apnea was not augmented. Therefore, this study does not support a neural interaction between plasma osmolality and chemoreceptor stimulation.

Implementation of an Integrative Holistic Healthcare Model for People Living with Parkinson’s Disease

PURPOSE Research demonstrates that people with Parkinsons disease (PD) benefit greatly from multidisciplinary medical care. Delaware does not have a Movement Disorder Center or a movement disorder specialist. To address this issue, the University of Delaware Nurse Managed Health Center (NMHC) developed a novel PD Telehealth Clinic serving individuals with PD and their caregivers throughout Delaware. DESIGN AND METHODS The PD clinic is based on a collaborative framework that uses synchronous videoconferencing telehealth technology to bring together out-of-state clinicians and scientists with expertise in PD to help deliver specialized care to PD patients and their caregivers. The team includes a movement disorder specialist, psychologists, nurse practitioners, researchers, physical and speech therapists, exercise physiologists, nutritionists, and graduate students. The PD Clinic delivery model seamlessly blends telehealth provider and onsite provider interactions, enabling the diagnosis, treatment, and ongoing management of PD. RESULTS In the first 6 months of the Parkinsons clinic opening, the nurse practitioners along with the movement disorder specialist evaluated 36 PD patients. Several patients have received recommendations to change their medication regimen by the movement disorder specialist. About 20 patients were referred to physical therapy, 7 to speech therapy, 9 to mental health services, 1 to occupational therapy, and 12 to local support groups. The location of the NMHC-PD clinic has reduced travel time and distance by as much as 1.5 hr or 80 miles, each way, and wait time for a new patient appointment is less than 3 months. IMPLICATIONS The NMHC - PD Telehealth Clinic provides access to specialized multidisciplinary and advanced care and was successfully implemented. This model can be replicated in other nurse managed health centers across the United States.