Effect of Remote Cardiac Monitoring System Design on Response Time to Critical Arrhythmias.

INTRODUCTION: In many hospitals across the country, electrocardiograms of multiple at-risk patients are monitored remotely by telemetry monitor watchers in a central location. However, there is limited evidence regarding best practices for designing these cardiac monitoring systems to ensure prompt detection and response to life-threatening events. To identify factors that may affect monitoring efficiency, we simulated critical arrhythmias in inpatient units with different monitoring systems and compared their efficiency in communicating the arrhythmias to a first responder. METHODS: This was a multicenter cross-sectional in situ simulation study. Simulation participants were monitor watchers and first responders (usually nurses) in 2 inpatient units in each of 3 hospitals. Manipulated variables included: (1) number of communication nodes between monitor watchers and first responders; (2) central monitoring station location-on or off the patient care unit; (3) monitor watchers' workload; (4) nurses' workload; and (5) participants' experience. RESULTS: We performed 62 arrhythmia simulations to measure response times of monitor watchers and 128 arrhythmia simulations to measure response times in patient care units. We found that systems in which an intermediary between monitor watchers and nurses communicated critical events had faster response times to simulated arrhythmias than systems in which monitor watchers communicated directly with nurses. Responses were also faster in units colocated with central monitoring stations than in those located remotely. As the perceived workload of nurses increased, response latency also increased. Experience did not affect response times. CONCLUSIONS: Although limited in our ability to isolate the effects of these factors from extraneous factors on central monitoring system efficiency, our study provides a roadmap for using in situ arrhythmia simulations to assess and improve monitoring performance.

Evaluator Training and Reliability for SMA Global Nusinersen Trials1.

BACKGROUND: Training methodology was established to optimize reliability of outcome measures in the nusinersen clinical trials. The Children's Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND), Hammersmith Functional Motor Scale Expanded (HFMSE), and Revised Upper Limb (RULM) were primary or secondary outcomes. METHODS: Video review, quarterly conference calls, and item scoring checks supported evaluator competence. Baseline and screening along with video review established intra and inter-rater reliability. RESULTS: Inter and intra-rater reliability were both excellent. Intraclass correlation coefficients (ICC) ranged between 0.906-0.994 across initial training meetings and 0.824-0.996 across annual retraining meetings. This was similar for CHOP INTEND (ICC = 0.824-0.951), HFMSE (ICC = 0.981-0.996), and RULM (ICC = 0.966-0.990). Intra-rater reliability for the CHOP INTEND, HFMSE, and RULM were ICC = 0.895 (95% CI: 0.852-0.926; n = 116), ICC = 0.959 (95% CI: 0.942-0.971; n = 125), and ICC = 0.948 (95% CI: 0.927-0.963; n = 126) respectively. CONCLUSIONS: Rigorous evaluator training ensures reliability of assessment of subjects with spinal muscular atrophy (SMA) in multicenter international trials.

Estimation of baseline dopamine D2 receptor occupancy in striatum and extrastriatal regions in humans with positron emission tomography with [18F] fallypride.

BACKGROUND: This study examined whether positron emission tomography (PET) studies with [18F] fallypride performed before and after alpha-methyl-para-tyrosine (AMPT) administration can be used to estimate baseline dopamine (DA) D2 receptor occupancy in striatal and extrastriatal regions. METHODS: Six normal subjects underwent PET with [18 F] fallypride before and after administration of AMPT. The DA D2 receptor binding potentials (bp) were calculated with the reference region method. Percent changes in bp in striatal and extrastriatal regions were calculated with both region-of-interest analysis and on a voxel by voxel basis with parametric images of DA D2 receptor levels. RESULTS: The results of the current study indicate that AMPT treatment significantly increased the bp in the caudate, putamen, ventral striatum, and substantia nigra. A trend level increase was seen in the medial thalamus. CONCLUSIONS: This study demonstrates that PET with [18F] fallypride can be used to estimate baseline DA D2 receptor occupancy in striatal and extrastriatal regions.