Implementation and challenges of portable blood gas measurements in air medical transport.

OBJECTIVES: Ventilator management in prehospital settings using end-tidal CO2 can lead to inappropriate ventilation in the absence of point of care blood gas (POCBG) measurements. Implementation of POCBG testing in helicopter Emergency Medical Services (HEMS) is limited in part because of concern for preanalytical and analytical errors due to altitude, vibration, and other associated environmental factors and due to insufficient documentation of implementation challenges. METHODS: We performed accuracy and precision verification studies using standard materials tested pre-, in-, and post-flight (n=10) in a large HEMS agency. Quality assurance error log data were extracted and summarized for common POCBG errors during the first 31 months of use and air medical transport personnel were surveyed regarding POCBG use (n=63). RESULTS: No clinically significant differences were found between pre-, in-, and post-flight blood gas measurements. Error log data demonstrated a reduction in device errors over time. Survey participants found troubleshooting device errors and learning new clinical processes to be the largest barriers to implementation. Continued challenges for participants coincided with error log data including temperature and sampling difficulties. Survey participants indicated that POCBG testing improved patient management. CONCLUSIONS: POCBG testing does not appear to be compromised by the HEMS environment. Temperature excursions can be reduced by use of insulated transport bags with heating and cooling packs. Availability of POCBG results in air medical transport appeared to improve ventilator management, increase recognition of ventilation-perfusion mismatch, and improve patient tolerance of ventilation.

Association Between Intravenous Fluid Bolus and Biomarker Trajectory During Prehospital Care.

Background: Patients with acute illness who receive intravenous (IV) fluids prior to hospital arrival may have a lower in-hospital mortality. To better understand whether this is a direct treatment effect or epiphenomenon of downstream care, we tested the association between a prehospital fluid bolus and the change in inflammatory cytokines measured at prehospital and emergency department timepoints in a sample of non-trauma, non-cardiac arrest patients at risk for critical illness. Methods: In a prospective cohort study, we screened 4,013 non-trauma, non-cardiac arrest encounters transported by City of Pittsburgh Emergency Medical Services (EMS) to 2 hospitals from August 2013 to February 2014. In 345 patients, we measured prehospital biomarkers (IL-6, IL-10, and TNF) at 2 time points: the time of prehospital IV access placement by EMS and at ED arrival. We determined the relative change for marker X as: ([XED - XEMS]/XEMS). We determined the risk-adjusted association between prehospital IV fluid bolus and relative change for each marker using multivariable linear regression. Results: Among 345 patients, 88 (26%) received a prehospital IV fluid bolus and 257 (74%) did not. Compared to patients who did not receive prehospital fluids, median prehospital IL-6 was greater initially in subjects receiving a prehospital IV fluid bolus (22.3 [IQR 6.4-113] vs. 11.5 [IQR 5.5-47.6]). Prehospital IL-10 and TNF were similar in both groups (IL-10: 3.5 [IQR 2.2-25.6] vs. 3.0 [IQR 1.9-9.0]; TNF: 7.5 [IQR 6.4-10.4] vs. 6.9 [IQR 6.0-8.3]). After adjustment for demographics, illness severity, and prehospital transport time, we observed a relative decrease in IL-6 at hospital arrival in those receiving a prehospital fluid bolus (adjusted ß = -10.0, 95% CI: -19.4, -0.6, p = 0.04), but we did not detect a significant change in IL-10 (p = 0.34) or TNF (p = 0.53). Conclusions: Among non-trauma, non-cardiac arrest patients at risk for critical illness, a prehospital IV fluid bolus was associated with a relative decrease in IL-6, but not IL-10 or TNF.

Prevalence and Predictors of Delay in Seeking Emergency Care in Patients Who Call 9-1-1 for Chest Pain.

BACKGROUND: Delay in seeking medical treatment for suspected acute coronary syndrome can lead to negative patient outcomes. OBJECTIVE: Our aim was to evaluate the prevalence and predictors of delay in seeking care in high-risk chest pain patients with or without acute coronary syndrome (ACS). METHODS: This was a secondary analysis of an observational cohort study of patients transported by Emergency Medical Services for a chief complaint of chest pain. Important demographic and clinical characteristics were extracted from electronic health records. Two independent reviewers adjudicated the presence of ACS. Logistic regression was used to model the predictors of delay in seeking care. RESULTS: The final sample included 743 patients (99% non-Hispanic). Overall, 24% presented > 12 h from onset of symptoms. Among those with ACS (n = 115), 14% presented > 12 h after onset of symptoms. Race, smoking, diabetes, and related symptoms were associated with delayed seeking behavior. In multivariate analysis, non-Caucasian race (black or others) was the only independent predictor of > 12 h delay in seeking care (odds ratio 1.4; 95% confidence interval 1.0-1.9). CONCLUSIONS: One in four patients with chest pain, including 14% of those with ACS, wait more than 12 h before seeking care. Compared to non-blacks, black patients are 40% more likely to delay seeking care > 12 h.

An interdisciplinary approach to inhospital stroke improves stroke detection and treatment time.

BACKGROUND: Inhospital stroke (IHS) is associated with high morbidity and mortality, likely related to multiple factors, including delayed time to recognition, associated comorbidities, and initial care from non-stroke trained providers. We hypothesized that guided revision of a formalized 'stroke code' system can improve diagnosis and time to thrombolysis and thrombectomy. METHODS: IHS activations occurring at a comprehensive stroke center between 2013 and 2016 were retrospectively analyzed to guide revisions of an established stroke code protocol to improve provider communication and time to imaging, reduce stroke mimic rate, and improve the use of parallel processing. After protocol implementation, we prospectively collected data between 2016 and 2017 for comparison with the pre-implementation group, including diagnostic accuracy and relevant time points (code call to examination, examination to imaging, and imaging to intervention). We report descriptive statistics for comparison of patient characteristics and time metrics (time to imaging and reperfusion after IHS activation). Multivariable regression analysis was performed to identify independent predictors of stroke mimics and time metrics. RESULTS: There were 136 cases in the pre-implementation group and 69 in the post-implementation group. A reduction in stroke mimics (52% vs 33%, P=0.01) occurred after protocol initiation. Mean time to imaging after stroke code call was 7.6 min shorter (P=0.026) and mean time from imaging to acute reperfusion therapy was 45.7 vs 19.8 min (P=0.05) in the pre- versus the post-implementation group. CONCLUSION: Revision of an existing IHS protocol was associated with a lower rate of stroke mimics, and a shorter time to intravenous and intra-arterial intervention.

Characteristics and Outcomes of Blood Product Transfusion During Critical Care Transport.

BACKGROUND: Civilian out-of-hospital transfusions have not been adequately studied. This study seeks to characterize patients receiving out-of-hospital blood product transfusion during critical care transport. STUDY DESIGN AND METHODS: We studied patients transported by a regional critical care air-medical service who received blood products during transport. This service carries two units of uncrossmatched packed Red Blood Cells (pRBCs) on every transport in addition to blood obtained from referring facilities. The pRBC are administered according to a protocol for the treatment of hemorrhagic shock or based on medical command physician order. Transfusion amount was categorized into three groups based on the volume transfused (<350 mL, 350-700 mL, >700 mL). The association between prehospital transfusion and in-hospital outcomes (mortality, subsequent blood transfusion and emergent surgery) was estimated using logistic regression models, controlling for age, first systolic blood pressure, first heart rate, Glasgow Coma Score, time of transfer, and length of hospital admission. RESULTS: Among the 1,440 critical care transports with transfusions examined, 81% were for medical patients, being gastrointestinal hemorrhage the most common indication (26%, CI 24-28%). pRBC transfusions were associated with emergent surgery (OR = 1.81, 95% CI = 1.31-2.52) and in-hospital transfusions (OR = 2.00, 95% CI = 1.46-2.76). Those with transfusions >700 mL were associated with emergent surgery (OR = 1.79, 95% CI = 1.10-2.92) and mortality (OR = 2.11; 95% CI = 1.21-3.69). CONCLUSIONS: In this sample, the majority of patients receiving blood products during air-medical transport were transfused for medic conditions; gastrointestinal hemorrhage was the most common chief complaint. The pRBC transfusions were associated with emergent surgery and in-hospital transfusion. Transfusions of >700 mL were associated with mortality.

Video Laryngoscopic Techniques Associated with Intubation Success in a Helicopter Emergency Medical Service System.

OBJECTIVES: Video laryngoscopy (VL) is a technical adjunct to facilitate endotracheal intubation (ETI). VL also provides objective data for training and quality improvement, allowing evaluation of the technique and airway conditions during ETI. Previous studies of factors associated with ETI success or failure are limited by insufficient nomenclature, individual recall bias and self-report. We tested whether the covariates in prehospital VL recorded data were associated with ETI success. We also measured association between time and clinical variables. METHODS: Retrospective review was conducted in a non-physician staffed helicopter emergency medical service system. ETI was typically performed using sedation and neuromuscular-blockade under protocolized orders. We obtained process and outcome variables from digitally recorded VL data. Patient characteristics data were also obtained from the emergency medical service record and linked to the VL recorded data. The primary outcome was to identify VL covariates associated with successful ETI attempts. RESULTS: Among 304 VL recorded ETI attempts in 268 patients, ETI succeeded for 244 attempts and failed for 60 attempts (first-pass success rate, 82% and overall success rate, 94%). Laryngoscope blade tip usually moved from a shallow position in the oropharynx to the vallecula. In the multivariable logistic regression analysis, attempt time (p = 0.02; odds ratio [OR] 0.99), Cormack-Lehane view (p < 0.001; OR 0.23), bodily fluids obstructing the view (p = 0.01; OR 0.29), and VL equipment failure (p < 0.001; OR 0.14) were negatively associated with successful attempts. Bodily fluids obstructing the view (p < 0.001; hazard ratio [HR] 0.51), VL equipment failure (p = 0.003; HR 0.42), shallow placement of blade tip within 4 seconds (p < 0.001; HR 0.40), number of forward movements (p < 0.001; HR 0.84), trauma (p = 0.04; HR 0.65), and neurological diagnosis (p = 0.04; HR 0.60) were associated with longer ETI attempt time. CONCLUSIONS: Bodily fluids obstructing the view, equipment problems, higher Cormack-Lehane view, and longer ETI attempt time were negatively associated with successful ETI attempts. Initially shallow blade tip position may associate with longer ETI time. VL is useful for measuring and describing multiple factors of ETI and can provide valuable data.

A multi-institutional analysis of prehospital tourniquet use.

BACKGROUND: Recent military studies demonstrated an association between prehospital tourniquet use and increased survival. The benefits of this prehospital intervention in a civilian population remain unclear. The aims of our study were to evaluate tourniquet use in the civilian population and to compare outcomes to previously published military experience. We hypothesized that incorporation of tourniquet use in the civilian population will result in an overall improvement in mortality. METHODS: This is a preliminary multi-institutional retrospective analysis of prehospital tourniquet (MIA-T) use of patients admitted to nine urban Level 1 trauma centers from January 2010 to December 2013. Patient demographics and mortality from a previous military experience by Kragh et al. (Ann Surg. 2009;249:1-7) were used for comparison. Patients younger than 18 years or with nontraumatic bleeding requiring tourniquet application were excluded. Data were analyzed using a two-tailed unpaired Student's t test with p < 0.05 as significant. RESULTS: A total of 197 patients were included. Tourniquets were applied effectively in 175 (88.8%) of 197 patients. The average Injury Severity Score (ISS) for MIA-T versus military was 11 ± 12.5 versus 14 ± 10.5, respectively (p = 0.02). The overall mortality and limb amputation rates for the MIA-T group were significantly lower than previously seen in the military population at 6 (3.0%) of 197 versus 22 (11.3%) of 194 (p = 0.002) and 37 (18.8%) of 197 versus 97 (41.8%) of 232 (p = 0.0001), respectively. CONCLUSION: Our study is the largest evaluation of prehospital tourniquet use in a civilian population to date. We found that tourniquets were applied safely and effectively in the civilian population. Adaptation of this prehospital intervention may convey a survival benefit in the civilian population. LEVEL OF EVIDENCE: Epidemiologic study, level V.

A comparative assessment of adverse event classification in the out-of-hospital setting.

OBJECTIVES: We sought to test reliability of two approaches to classify adverse events (AEs) associated with helicopter EMS (HEMS) transport. METHODS: The first approach for AE classification involved flight nurses and paramedics (RN/Medics) and mid-career emergency physicians (MC-EMPs) independently reviewing 50 randomly selected HEMS medical records. The second approach involved RN/Medics and MC-EMPs meeting as a group to openly discuss 20 additional medical records and reach consensus-based AE decision. We compared all AE decisions to a reference criterion based on the decision of three senior emergency physicians (Sr-EMPs). We designed a study to detect an improvement in agreement (reliability) from fair (kappa = 0.2) to moderate (kappa = 0.5). We calculated sensitivity, specificity, percent agreement, and positive and negative predictive values (PPV/NPV). RESULTS: For the independent reviews, the Sr-EMP group identified 26 AEs while individual clinician reviewers identified between 19 and 50 AEs. Agreement on the presence/absence of an AE between Sr-EMPs and three MC-EMPs ranged from κ = 0.20 to κ = 0.25. Agreement between Sr-EMPs and three RN/Medics ranged from κ = 0.11 to κ = 0.19. For the consensus/open-discussion approach, the Sr-EMPs identified 13 AEs, the MC-EMP group identified 18 AEs, and RN/medic group identified 36 AEs. Agreement between Sr-EMPs and MC-EMP group was (κ = 0.30 95%CI -0.12, 0.72), whereas agreement between Sr-EMPs and RN/medic group was (κ = 0.40 95%CI 0.01, 0.79). Agreement between all three groups was fair (κ = 0.33, 95%CI 0.06, 0.66). Percent agreement (58-68%) and NPV (63-76%) was moderately dissimilar between clinicians, while sensitivity (25-80%), specificity (43-97%), and PPV (48-83%) varied. CONCLUSIONS: We identified a higher level of agreement/reliability in AE decisions utilizing a consensus-based approach for review rather than independent reviews.

Measuring adverse events in helicopter emergency medical services: establishing content validity.

INTRODUCTION: We sought to create a valid framework for detecting adverse events (AEs) in the high-risk setting of helicopter emergency medical services (HEMS). METHODS: We assembled a panel of 10 expert clinicians (n = 6 emergency medicine physicians and n = 4 prehospital nurses and flight paramedics) affiliated with a large multistate HEMS organization in the Northeast US. We used a modified Delphi technique to develop a framework for detecting AEs associated with the treatment of critically ill or injured patients. We used a widely applied measure, the content validity index (CVI), to quantify the validity of the framework's content. RESULTS: The expert panel of 10 clinicians reached consensus on a common AE definition and four-step protocol/process for AE detection in HEMS. The consensus-based framework is composed of three main components: (1) a trigger tool, (2) a method for rating proximal cause, and (3) a method for rating AE severity. The CVI findings isolate components of the framework considered content valid. CONCLUSIONS: We demonstrate a standardized process for the development of a content-valid framework for AE detection. The framework is a model for the development of a method for AE identification in other settings, including ground-based EMS.

Association between poor sleep, fatigue, and safety outcomes in emergency medical services providers.

OBJECTIVE: To determine the association between poor sleep quality, fatigue, and self-reported safety outcomes among emergency medical services (EMS) workers. METHODS: We used convenience sampling of EMS agencies and a cross-sectional survey design. We administered the 19-item Pittsburgh Sleep Quality Index (PSQI), 11-item Chalder Fatigue Questionnaire (CFQ), and 44-item EMS Safety Inventory (EMS-SI) to measure sleep quality, fatigue, and safety outcomes, respectively. We used a consensus process to develop the EMS-SI, which was designed to capture three composite measurements of EMS worker injury, medical errors and adverse events (AEs), and safety-compromising behaviors. We used hierarchical logistic regression to test the association between poor sleep quality, fatigue, and three composite measures of EMS worker safety outcomes. RESULTS: We received 547 surveys from 30 EMS agencies (a 35.6% mean agency response rate). The mean PSQI score exceeded the benchmark for poor sleep (6.9, 95% confidence interval [CI] 6.6, 7.2). More than half of the respondents were classified as fatigued (55%, 95% CI 50.7, 59.3). Eighteen percent of the respondents reported an injury (17.8%, 95% CI 13.5, 22.1), 41% reported a medical error or AE (41.1%, 95% CI 36.8, 45.4), and 90% reported a safety-compromising behavior (89.6%, 95% CI 87, 92). After controlling for confounding, we identified 1.9 greater odds of injury (95% CI 1.1, 3.3), 2.2 greater odds of medical error or AE (95% CI 1.4, 3.3), and 3.6 greater odds of safety-compromising behavior (95% CI 1.5, 8.3) among fatigued respondents versus nonfatigued respondents. CONCLUSIONS: In this sample of EMS workers, poor sleep quality and fatigue are common. We provide preliminary evidence of an association between sleep quality, fatigue, and safety outcomes.