Dopaminergic challenge with bromocriptine one month after mild traumatic brain injury: altered working memory and BOLD response.

Catecholamines, particularly dopamine, modulate working memory (WM). Altered sensitivity to dopamine might play a role in WM changes observed after traumatic brain injury (TBI). Thirty-one healthy controls (HC) and 26 individuals with mild TBI (MTBI) 1 month after injury were challenged with bromocriptine versus placebo before administration of a verbal WM functional MRI task. Bromocriptine was associated with improved WM performance in the HC but not the MTBI group. On bromocriptine, the MTBI group showed increased activation outside of a task-specific region of interest. Findings are consistent with the hypothesis that individuals with MTBI have altered responsivity to dopamine.

Alpha-2 adrenergic challenge with guanfacine one month after mild traumatic brain injury: altered working memory and BOLD response.

Alterations in working memory (WM) are common after traumatic brain injury (TBI). Frontal catecholaminergic systems, including the alpha-2 adrenergic system, modulate WM function and may be affected in TBI. We hypothesized that administration of an alpha-2 adrenergic agonist might improve WM after mild TBI (MTBI). Thirteen individuals with MTBI 1month after injury and 14 healthy controls (HC) were challenged with guanfacine and placebo prior to administration of a verbal WM functional MRI task. Guanfacine was associated with improved WM performance in the MTBI but not the HC group. On guanfacine the MTBI group showed increased activation within a WM task-specific region of interest. Findings are consistent with the hypothesis that alterations in WM after MTBI may be improved with the alpha-2 agonist guanfacine.

Primary percutaneous coronary intervention for patients presenting with ST-elevation myocardial infarction: process improvements in rural prehospital care delivered by emergency medical services.

BACKGROUND: Safe and effective patient care for ST-elevation myocardial infarction (STEMI) relies on prompt emergency medical service (EMS) and established care coordination with receiving hospitals to conduct primary percutaneous coronary intervention (PCI). Likewise, a new emphasis has been placed on first medical contact-to-balloon (E2B) times as opposed to door-to-balloon times, identifying prehospital care as an important contributing factor for high-quality STEMI care. Therefore, we evaluated EMS processes of care before and after a period of continuous quality improvement to improve E2B times in our rural tertiary care medical center. METHODS: A retrospective, consecutive cohort study was conducted on 177 patients who received primary PCI at Dartmouth-Hitchcock Medical Center, a rural hospital, from January 1, 2006 to October 31, 2009. This cohort was stratified from January 1, 2008 to May 1, 2008 (n = 88) and May 1, 2008 to October 31, 2009 (n = 89), to acknowledge periods of no improvement (pre) and continuous quality improvement (post) in STEMI care. Primary outcome measures included frequency of non-PCI-capable hospital bypass, E2B, and frequency of prehospital electrocardiogram (ECG) and cardiac catheterization laboratory (CCL) activation. Descriptive statistics and log-rank tests were used to determine whether measures differed significantly by time period. A time-to-event analysis was conducted using a Cox proportional hazards model to assess the impact of outcomes measures on E2B pre/post-May 1, 2008. RESULTS: Patients who presented before May 1, 2008 had longer E2B times compared with patients in the post-May 1, 2008 cohort (145.1 minutes vs 115.2 minutes, t test P = .01). A log-rank test confirmed this (pre: 130 minutes vs post: 106 minutes, χ(2) = 5.3, log-rank P = .02). Similarly, patients who presented before May 1, 2008 had lower percentages of prehospital ECGs (49% vs 80%, P = .001) and CCL activations (4% vs 32%, P < .001). When prehospital ECGs (140 minutes vs 106 minutes, χ(2) = 5.9, log-rank P = .01) or CCL activations (125 minutes vs 98 minutes, χ(2) = 4.2, log-rank P = .04) were conducted, E2B times were significantly reduced. Patients who received both prehospital ECGs and prehospital CCL activations had significantly reduced E2B times compared with those who did not (125 minutes vs 91 minutes, χ(2) = 4.8, P = .02). CONCLUSIONS: The time saving benefits of prehospital ECGs may not be fully realized unless prehospital CCL activations also occur. EMS providers achieved further reductions in median E2B of approximately 24 minutes when prehospital ECGs were combined with prehospital CCL activation. Every effort should be made by PCI-capable medical centers to assess prehospital STEMI care and to integrate EMS providers into regional STEMI care quality improvement initiatives and education.

Primary percutaneous coronary intervention for patients presenting with ST-segment elevation myocardial infarction: process improvement in a rural ST-segment elevation myocardial infarction receiving center.

BACKGROUND: Rural ST-segment elevation myocardial infarction (STEMI) care networks may be particularly disadvantaged in achieving a door-to-balloon time (D2B) of less than or equal to 90 minutes recommended in current guidelines. ST-ELEVATION MYOCARDIAL INFARCTION PROCESS UPGRADE PROJECT: A multidisciplinary STEMI process upgrade group at a rural percutaneous coronary intervention center implemented evidence-based strategies to reduce time to electrocardiogram (ECG) and D2B, including catheterization laboratory activation triggered by either a prehospital ECG demonstrating STEMI or an emergency department physician diagnosing STEMI, single-call catheterization laboratory activation, catheterization laboratory response time less than or equal to 30 minutes, and prompt data feedback. EVALUATING SUCCESS: An ongoing regional STEMI registry was used to collect process time intervals, including time to ECG and D2B, in a consecutive series of STEMI patients presenting before (group 1) and after (group 2) strategy implementation. Significant reductions in time to first ECG in the emergency department and D2B were seen in group 2 compared with group 1. CONCLUSIONS: Important improvement in the process of acute STEMI patient care was accomplished in the rural percutaneous coronary intervention center setting by implementing evidence-based strategies.