Todd Chassee

Clinical Predictors of Accurate Prehospital Stroke Recognition

Background and Purpose— Prehospital activation of in-hospital stroke response hastens treatment but depends on accurate emergency medical services (EMS) stroke recognition. We sought to measure EMS stroke recognition accuracy and identify clinical factors associated with correct stroke identification. Methods— Using EMS and hospital records, we assembled a cohort of EMS-transported suspect, confirmed, or missed ischemic stroke or transient ischemic attack cases. The sensitivity and positive predictive value (PPV) for EMS stroke recognition were calculated using the hospital discharge diagnosis as the gold standard. We used multivariable logistic regression analysis to determine the association between Cincinnati Prehospital Stroke Scale use and EMS stroke recognition. Results— During a 12-month period, 441 EMS-transported patients were enrolled; of which, 371 (84.1%) were EMS-suspected strokes and 70 (15.9%) were EMS-missed strokes. Overall, 264 cases (59.9%) were confirmed as either ischemic stroke (n=186) or transient ischemic attack (n=78). The sensitivity of EMS stroke recognition was 73.5% (95% confidence interval, 67.7–78.7), and PPV was 52.3% (95% confidence interval, 47.1–57.5). Sensitivity (84.7% versus 30.9%; P<0.0001) and PPV (56.2% versus 30.4%; P=0.0004) were higher among cases with Cincinnati Prehospital Stroke Scale documentation. In multivariate analysis, Cincinnati Prehospital Stroke Scale documentation was independently associated with EMS sensitivity (odds ratio, 12.0; 95% confidence interval, 5.7–25.5) and PPV (odds ratio, 2.5; 95% confidence interval, 1.3–4.7). Conclusions— EMS providers recognized 3 quarters of the patients with ischemic stroke and transient ischemic attack; however, half of EMS-suspected strokes were false positives. Documentation of a Cincinnati Prehospital Stroke Scale was associated with higher EMS stroke recognition sensitivity and PPV.

The Quality of Prehospital Ischemic Stroke Care: Compliance with Guidelines and Impact on In-hospital Stroke Response

BACKGROUND A number of emergency medical services (EMSs) performance measures for stroke have been proposed to promote early stroke recognition and rapid transportation to definitive care. This study examined performance measure compliance among EMS-transported stroke patients and the relationship between compliance and in-hospital stroke response. METHODS Eight quality indicators were derived from American Stroke Association guidelines. A prospective cohort of consecutive, EMS-transported patients discharged from 2 large Midwestern stroke centers with a diagnosis of acute ischemic stroke was identified. Data were abstracted from hospital and EMS records. Compliance with 8 prehospital quality indicators was calculated. Univariate and multivariable logistic regression analysis were performed to measure the association between prehospital compliance and a binary outcome of door-to-computed tomography (CT) time less than or equal to 25 minutes. RESULTS Over the 12 month study period, 186 EMS-transported ischemic stroke patients were identified. Compliance was highest for prehospital documentation of a glucose level (86.0%) and stroke screen (78.5%) and lowest for on-scene time less than or equal to 15 minutes (46.8%), hospital prenotification (56.5%), and transportation at highest priority (55.4%). After adjustment for age, time from symptom onset, and stroke severity, transportation at highest priority (odds ratio [OR], 13.45) and hospital prenotification (OR, 3.75) were both associated with significantly faster door-to-CT time. No prehospital quality metric was associated with tissue-plasminogen activator delivery. CONCLUSIONS EMS transportation at highest priority and hospital prenotification were associated with faster in-hospital stroke response and represent logical targets for EMS quality improvement efforts.

Pediatric Prehospital Medication Dosing Errors: A Mixed-Methods Study

ABSTRACT Prehospital dosing errors affect approximately 56,000 US children yearly. To decrease these errors, barriers, enablers and solutions from the paramedic (EMT-P) and medical director (MD) standpoint need to be understood. We conducted a mixed-methods study of EMT-P and MDs in Michigan utilizing focus groups (FG). FGs were held at EMS agencies and state EMS conferences. Questions focused on the drug dose delivery process, barriers and enablers to correct dosing and possible solutions to decrease errors. Responses were coded by the research team for themes and number of response mentions. Participants completed a pre-FG survey on pediatric experience and agency characteristics. There were 35 EMT-P and 9 MD participants: 43% of EMT-Ps had been practicing > 10 years, 11% had been practicing < 1 year; and 25% reported they had not administered a drug dose to a child in the last 12 months. EMT-Ps who were “very comfortable” with their ability to administer a correct drug dose to infants, toddlers, school-aged, and adolescents were: 5%, 7%, 10%, and 54%, respectively. FGs identified themes of: difficulty obtaining weight, infrequent pediatric encounters, infrequent/inadequate pediatric training, difficulties with drug packaging, drug bags that were not “EMS friendly,” difficulty with drug calculations, and lack of dosing aids. Simplification of dose delivery, an improved length based tape for EMS, pediatric checklists, and dose cards in mL were given as solutions. This mixed-methods study identified barriers and potential solutions to reducing prehospital pediatric drug dosing errors. Solutions should be thoroughly tested prior to implementation.

Bystander Cardiopulmonary Resuscitation Is Clustered and Associated With Neighborhood Socioeconomic Characteristics: A Geospatial Analysis of Kent County, Michigan

OBJECTIVES Geographic clustering of bystander cardiopulmonary resuscitation (CPR) is associated with demographic and socioeconomic features of the community where out-of-hospital cardiac arrest (OHCA) occurred, although this association remains largely untested in rural areas. With a significant rural component and relative racial homogeneity, Kent County, Michigan, provides a unique setting to externally validate or identify new community features associated with bystander CPR. Using a large, countywide data set, we tested for geographic clustering of bystander CPR and its associations with community socioeconomic features. METHODS Secondary analysis of adult OHCA subjects (2010-2015) in the Cardiac Arrest Registry to Enhance Survival (CARES) data set for Kent County, Michigan. After linking geocoded OHCA cases to U.S. census data, we used Morans I-test to assess for spatial autocorrelation of population-weighted cardiac arrest rate by census block group. Getis-Ord Gi statistic assessed for spatial clustering of bystander CPR and mixed-effects hierarchical logistic regression estimated adjusted associations between community features and bystander CPR. RESULTS Of 1,592 subjects, 1,465 met inclusion criteria. Geospatial analysis revealed significant clustering of OHCA in more populated/urban areas. Conversely, bystander CPR was less likely in these areas (99% confidence) and more likely in suburban and rural areas (99% confidence). Adjusting for clinical, demographic, and socioeconomic covariates, bystander CPR was associated with public location (odds ratio [OR] = 1.19; 95% confidence interval [CI] = 1.03-1.39), initially shockable rhythms (OR = 1.48; 95% CI = 1.12-1.96), and those in urban neighborhoods (OR = 0.54; 95% CI = 0.38-0.77). CONCLUSIONS Out-of-hospital cardiac arrest and bystander CPR are geographically clustered in Kent County, Michigan, but bystander CPR is inversely associated with urban designation. These results offer new insight into bystander CPR patterns in mixed urban and rural regions and afford the opportunity for targeted community CPR education in areas of low bystander CPR prevalence.

Emergency Medical Dispatchers Can Obtain Accurate Pediatric Weights from 9-1-1 Callers

Abstract Background: Prehospital pediatric drug dosing errors affect 56,000 U.S. children annually. An accurate weight is the first step in accurate dosing. To date, the accuracy of Emergency Medical Dispatcher (EMD) obtained weights has not been evaluated. We hypothesized that EMD could obtain accurate pediatric weights. Methods: We used a convenience sample of patients 12 years and younger that were transported by EMS to one childrens hospital. EMD obtained patient weight (DW) from the 9-1-1 caller. Paramedics reported their estimate of the patients weight on arrival to the hospital (PW). The DW and PW were compared to the hospital scale weight (HW) for accuracy. Results: A total of 197 patients were included. Parent/guardians were the most frequent 9-1-1 callers (74%). The most frequent method utilized by paramedics to obtain patient weight was to ask a family member. For 0–2 year olds, the mean differences between HW and DW/PW were 0.239kg (SD 3.117)/ -0.374 (SD 2.528). For 3–7 year olds, the mean differences between HW and DW/PW were 0.041kg (SD 4.684)/1.007 (SD 2.466). For 8–11 year olds the mean difference between HW and DW/PW was 2.768 kg (SD 10.926)/ 1.919 (SD 6.909). Conclusion: EMD were able to obtain pediatric patient weights with relative accuracy for patients 0–7 year old. Using this EMD-obtained weight to carry out a drug dose calculation would be unlikely to result in a clinically significant dose error in the vast majority of cases. Communicating an EMD-obtained weight to EMS crews en route to a pediatric patient offers additional preparation time for drug calculations, which could improve accuracy.

BET 2: Usefulness of epinephrine in out-of-hospital cardiac arrest

A short-cut review was carried out to establish whether prehospital adrenaline affects long-term morbidity or mortality after out-of-hospital cardiac arrest. Fifty-five papers were found using the reported search. Of these, three presented the best evidence to answer the clinical question. The author, date and country of publication, patient group studied, study type, relevant outcomes, results and study weaknesses of these best papers are tabulated. It is concluded that while epinephrine used as an adjunctive treatment during out-of-hospital cardiac arrest (OHCA) may improve return of spontaneous circulation (ROSC) and survival to hospital, it does not improve survival to discharge or neurological outcome.

Does Non-Targeted Community CPR Training Increase Bystander CPR Frequency?

Abstract Objective: Only 37% of out-of-hospital cardiac arrests (OHCA) receive bystander Cardiopulmonary resuscitation (CPR) in Kent County, MI. In May 2014, prehospital providers offered one-time, point-of-contact compression-only CPR training to 2,253 passersby at 7 public locations in Grand Rapids, Michigan. To assess the impact of this intervention, we compared bystander CPR frequency and clinical outcomes in regions surrounding training sites before and after the intervention, adjusting for prehospital covariates. We aimed to assess the effect of this broad, non-targeted intervention on bystander CPR frequency, type of CPR utilized, and clinical outcomes. We also tested for differences in geospatial variation of bystander CPR and clinical outcomes clustered around training sites. Methods: Retrospective, observational, before-after study of adult, EMS-treated OHCA in Kent County from January 1, 2010 to December 31, 2015. We generated a 5-kilometer radius surrounding each training site to estimate any geospatial influence that training sites might have on bystander CPR frequency in nearby OHCA cases. Chi-squared, Fishers exact, and t-tests assessed differences in subject features. Difference-in-differences analysis with generalized estimating equation (GEE) modeling assessed bystander CPR frequency, adjusting for training site, covariates (age, sex, witnessed, shockable rhythm, public location), and clustering around training sites. Similar modeling tested for changes in bystander CPR type, return of spontaneous circulation (ROSC), survival to hospital discharge, and cerebral performance category (CPC) of 1–2 at hospital discharge. Results: We included 899 cases before and 587 cases post-intervention. Overall, we observed no increase in the frequency of bystander CPR or favorable clinical outcomes. We did observe an increase in compression-only CPR, but this was paradoxically restricted to OHCA cases falling outside radii around training sites. In adjusted modeling, the bystander CPR training intervention was not associated with bystander CPR frequency (β −0.002; 95% CI −0.16, 0.15), compression-only CPR (β −0.06; 95% CI −0.15, 0.02), ROSC (β −0.06; 95% CI −0.21, 0.25), survival (β −0.02; 95% CI −0.11, 0.06), or favorable neurologic outcome (β −0.01; 95% CI −0.07, 0.09). Conclusions: We observed no impact in bystander CPR performance or outcomes from a blanket, non-targeted approach to community CPR education. The effect of targeted CPR education in locales with known low bystander CPR rates should be tested in this region.

Emergency Dispatcher Stroke Recognition: Associations with Downstream Care

Abstract Objective: As the first point of contact for patients activating emergency medical services (EMS), emergency dispatchers have the earliest opportunity to recognize stroke. We sought to quantify dispatcher stroke recognition and its relationships with EMS stroke recognition and response speed. Methods: We assembled a cohort of consecutive EMS-transported patients with a dispatcher suspected stroke or a hospital discharge diagnosis of stroke or transient ischemic attack (TIA). Dispatcher sensitivity and positive predictive value (PPV) for stroke recognition were calculated. Multivariable logistic regression analysis was used to determine predictors of dispatcher recognition and relationships between dispatcher recognition and downstream care. Results: During a 12-month period, 601 patients met inclusion criteria. Dispatchers suspected stroke in 229/324 (sensitivity = 70.7% [65.5 to 75.4%]) confirmed stroke/TIA cases and correctly assigned a suspected stroke label in 229/506 cases (PPV = 45.3% [41.0 to 49.6%]). Dispatchers had higher odds of recognizing ischemic strokes (aOR 3.4 [1.4 to 8.5]) and lower odds of recognizing patients with visual deficits (aOR = 0.4 [0.2 to 0.9]) or vomiting (aOR = 0.3 [0.1 to 0.9]). Dispatcher suspected stroke cases received more on-scene stroke screens (79.0% vs. 54.7%, p < 0.0001) and were more often recognized by EMS as strokes (77.7% vs. 57.9%, p = 0.0005). Dispatcher recognition was independently associated with EMS stroke recognition (aOR = 3.8 [1.9 to 7.7]), but not with transportation times, door-to-CT times, or t-PA delivery. Conclusions: Emergency dispatcher stroke recognition is associated with higher rates of on-scene stroke scale performance and EMS ischemic stroke recognition but not with reduced transport times, door-to-CT times, or t-PA treatment.