Need for Emergent Intervention within 6 Hours: A Novel Prediction Model for Hospital Trauma Triage.

Objective: A tiered trauma team activation system allocates resources proportional to patients' needs based upon injury burden. Previous trauma hospital-triage models are limited to predicting Injury Severity Score which is based on > 10% all-cause in-hospital mortality, rather than need for emergent intervention within 6 hours (NEI-6). Our aim was to develop a novel prediction model for hospital-triage that utilizes criteria available to the EMS provider to predict NEI-6 and the need for a trauma team activation.Methods: A regional trauma quality collaborative was used to identify all trauma patients ≥ 16 years from the American College of Surgeons-Committee on Trauma verified Level 1 and 2 trauma centers. Logistic regression and random forest were used to construct two predictive models for NEI-6 based on clinically relevant variables. Restricted cubic splines were used to model nonlinear predictors. The accuracy of the prediction model was assessed in terms of discrimination.Results: Using data from 12,624 patients for the training dataset (62.6% male; median age 61 years; median ISS 9) and 9,445 patients for the validation dataset (62.6% male; median age 59 years; median ISS 9), the following significant predictors were selected for the prediction models: age, gender, field GCS, vital signs, intentionality, and mechanism of injury. The final boosted tree model showed an AUC of 0.85 in the validation cohort for predicting NEI-6.Conclusions: The NEI-6 trauma triage prediction model used prehospital metrics to predict need for highest level of trauma activation. Prehospital prediction of major trauma may reduce undertriage mortality and improve resource utilization.

Advanced reperfusion strategies for patients with out-of-hospital cardiac arrest and refractory ventricular fibrillation (ARREST): a phase 2, single centre, open-label, randomised controlled trial.

BACKGROUND: Among patients with out-of-hospital cardiac arrest (OHCA) and ventricular fibrillation, more than half present with refractory ventricular fibrillation unresponsive to initial standard advanced cardiac life support (ACLS) treatment. We did the first randomised clinical trial in the USA of extracorporeal membrane oxygenation (ECMO)-facilitated resuscitation versus standard ACLS treatment in patients with OHCA and refractory ventricular fibrillation. METHODS: For this phase 2, single centre, open-label, adaptive, safety and efficacy randomised clinical trial, we included adults aged 18-75 years presenting to the University of Minnesota Medical Center (MN, USA) with OHCA and refractory ventricular fibrillation, no return of spontaneous circulation after three shocks, automated cardiopulmonary resuscitation with a Lund University Cardiac Arrest System, and estimated transfer time shorter than 30 min. Patients were randomly assigned to early ECMO-facilitated resuscitation or standard ACLS treatment on hospital arrival by use of a secure schedule generated with permuted blocks of randomly varying block sizes. Allocation concealment was achieved by use of a randomisation schedule that required scratching off an opaque layer to reveal assignment. The primary outcome was survival to hospital discharge. Secondary outcomes were safety, survival, and functional assessment at hospital discharge and at 3 months and 6 months after discharge. All analyses were done on an intention-to-treat basis. The study qualified for exception from informed consent (21 Code of Federal Regulations 50.24). The ARREST trial is registered with ClinicalTrials.gov, NCT03880565. FINDINGS: Between Aug 8, 2019, and June 14, 2020, 36 patients were assessed for inclusion. After exclusion of six patients, 30 were randomly assigned to standard ACLS treatment (n=15) or to early ECMO-facilitated resuscitation (n=15). One patient in the ECMO-facilitated resuscitation group withdrew from the study before discharge. The mean age was 59 years (range 36-73), and 25 (83%) of 30 patients were men. Survival to hospital discharge was observed in one (7%) of 15 patients (95% credible interval 1·6-30·2) in the standard ACLS treatment group versus six (43%) of 14 patients (21·3-67·7) in the early ECMO-facilitated resuscitation group (risk difference 36·2%, 3·7-59·2; posterior probability of ECMO superiority 0·9861). The study was terminated at the first preplanned interim analysis by the National Heart, Lung, and Blood Institute after unanimous recommendation from the Data Safety Monitoring Board after enrolling 30 patients because the posterior probability of ECMO superiority exceeded the prespecified monitoring boundary. Cumulative 6-month survival was significantly better in the early ECMO group than in the standard ACLS group. No unanticipated serious adverse events were observed. INTERPRETATION: Early ECMO-facilitated resuscitation for patients with OHCA and refractory ventricular fibrillation significantly improved survival to hospital discharge compared with standard ACLS treatment. FUNDING: National Heart, Lung, and Blood Institute.

Prehospital Treatment of Acute Pulmonary Edema with Intravenous Bolus and Infusion Nitroglycerin.

OBJECTIVE: The study describes the implementation of a prehospital treatment algorithm that included intravenous (IV) bolus (IVB) nitroglycerin (NTG) followed by maintenance infusion for the treatment of acute pulmonary edema (APE) in a single, high-volume Emergency Medical Services (EMS) system. METHODS: This is a retrospective chart review of patients who received IVB NTG for APE in a large EMS system in Minnesota and Wisconsin (USA). Inclusion criteria for treatment included a diagnosis of APE, systolic blood pressure ≥120mmHg, and oxygen saturation (SpO2) ≤93% following 800mcg of sublingual NTG. Patients received a 400mcg IVB of NTG, repeated every two minutes as needed, and subsequent infusion at 80mcg/min for transport times ≥10 minutes. RESULTS: Forty-four patients were treated with IVB NTG. The median total bolus dose was 400mcg. Twenty patients were treated with NTG infusion following IVB NTG. The median infusion rate was 80mcg/min. For all patients, the initial median blood pressure was 191/113mmHg. Five minutes following IVB NTG, it was 160/94mmHg, and on arrival to the emergency department (ED) it was 152/90mmHg. Five minutes after the initial dose of IVB NTG, median SpO2 increased to 92% from an initial reading of 88% and was 94% at hospital arrival. One episode of transient hypotension occurred during EMS transport. CONCLUSION: Patients treated with IVB NTG for APE had reduction in blood pressure and improvement in SpO2 compared to their original presentation. Prehospital treatment of APE with IVB appears to be feasible and safe. A randomized trial is needed to confirm these findings.

Improved Survival With Extracorporeal Cardiopulmonary Resuscitation Despite Progressive Metabolic Derangement Associated With Prolonged Resuscitation.

BACKGROUND: The likelihood of neurologically favorable survival declines with prolonged resuscitation. However, the ability of extracorporeal cardiopulmonary resuscitation (ECPR) to modulate this decline is unknown. Our aim was to examine the effects of resuscitation duration on survival and metabolic profile in patients who undergo ECPR for refractory ventricular fibrillation/ventricular tachycardia out-of-hospital cardiac arrest. METHODS: We retrospectively evaluated survival in 160 consecutive adults with refractory ventricular fibrillation/ventricular tachycardia out-of-hospital cardiac arrest treated with the University of Minnesota (UMN) ECPR protocol (transport with ongoing cardiopulmonary resuscitation [CPR] to the cardiac catheterization laboratory for ECPR) compared with 654 adults who had received standard CPR in the amiodarone arm of the ALPS trial (Amiodarone, Lidocaine, or Placebo Study). We evaluated the metabolic changes and rate of survival in relation to duration of CPR in UMN-ECPR patients. RESULTS: Neurologically favorable survival was significantly higher in UMN-ECPR patients versus ALPS patients (33% versus 23%; P=0.01) overall. The mean duration of CPR was also significantly longer for UMN-ECPR patients versus ALPS patients (60 minutes versus 35 minutes; P<0.001). Analysis of the effect of CPR duration on neurologically favorable survival demonstrated significantly higher neurologically favorable survival for UMN-ECPR patients compared with ALPS patients at each CPR duration interval <60 minutes; however, longer CPR duration was associated with a progressive decline in neurologically favorable survival in both groups. All UMN-ECPR patients with 20 to 29 minutes of CPR (8 of 8) survived with neurologically favorable status compared with 24% (24 of 102) of ALPS patients with the same duration of CPR. There were no neurologically favorable survivors in the ALPS cohort with CPR ≥40 minutes, whereas neurologically favorable survival was 25% (9 of 36) for UMN-ECPR patients with 50 to 59 minutes of CPR and 19% with ≥60 minutes of CPR. Relative risk of mortality or poor neurological function was significantly reduced in UMN-ECPR patients with CPR duration ≥60 minutes. Significant metabolic changes included decline in pH, increased lactic acid and arterial partial pressure of carbon dioxide, and thickened left ventricular wall with prolonged professional CPR. CONCLUSIONS: ECPR was associated with improved neurologically favorable survival at all CPR durations <60 minutes despite severe progressive metabolic derangement. However, CPR duration remains a critical determinate of survival.

The Minnesota mobile extracorporeal cardiopulmonary resuscitation consortium for treatment of out-of-hospital refractory ventricular fibrillation: Program description, performance, and outcomes.

BACKGROUND: We describe implementation, evaluate performance, and report outcomes from the first program serving an entire metropolitan area designed to rapidly deliver extracorporeal membrane oxygenation (ECMO)-facilitated resuscitation to patients with refractory ventricular fibrillation/ventricular tachycardia (VF/VT) out-of-hospital cardiac arrest (OHCA). METHODS: This observational cohort study analyzed consecutive patients prospectively enrolled in the Minnesota Mobile Resuscitation Consortium's ECMO-facilitated resuscitation program. Entry criteria included: 1) adults (aged 18-75), 2) VF/VT OHCA, 3) no return of spontaneous circulation following 3 shocks, 4) automated cardiopulmonary resuscitation with a Lund University Cardiac Arrest System (LUCAS™), and 5) estimated transfer time of < 30 min. The primary endpoint was functionally favorable survival to hospital discharge with Cerebral Performance Category (CPC) 1 or 2. Secondary endpoints included 3-month functionally favorable survival, program benchmarks, ECMO cannulation rate, and safety. Essential program components included emergency medical services, 3 community ECMO Initiation Hospitals with emergency department ECMO cannulation sites and 24/7 cardiac catheterization laboratories, a 24/7 mobile ECMO cannulation team, and a single, centralized ECMO intensive care unit. FINDINGS: From December 1, 2019 to April 1, 2020, 63 consecutive patients were transported and 58 (97%) met criteria and were treated by the mobile ECMO service. Mean age was 57 ± 1.8 years; 46/58 (79%) were male. Program benchmarks were variably met, 100% of patients were successfully cannulated, and no safety issues were identified. Of the 58 patients, 25/58 (43% [CI:31-56%]) were both discharged from the hospital and alive at 3 months with CPC 1 or 2. INTERPRETATION: This first, community-wide ECMO-facilitated resuscitation program in the US demonstrated 100% successful cannulation, 43% functionally favorable survival rates at hospital discharge and 3 months, as well as safety. The program provides a potential model of this approach for other communities. FUNDING: The Helmsley Charitable Trust.

Coronary Artery Disease in Patients With Out-of-Hospital Refractory Ventricular Fibrillation Cardiac Arrest.

BACKGROUND: The prevalence of coronary artery disease (CAD) among patients with refractory out-of-hospital (OH) ventricular fibrillation (VF)/ventricular tachycardia (VT) cardiac arrest is unknown. OBJECTIVES: The goal of this study was to describe the prevalence and complexity of CAD and report survival to hospital discharge in patients experiencing refractory VF/VT cardiac arrest treated with a novel protocol of early transport to a cardiac catheterization laboratory (CCL) for extracorporeal life support (ECLS) and revascularization. METHODS: Between December 1, 2015, and December 1, 2016, consecutive adult patients with refractory OH VF/VT cardiac arrest requiring ongoing cardiopulmonary resuscitation were transported by emergency medical services to the CCL. ECLS, coronary angiography, and percutaneous coronary intervention were performed, as appropriate. Functionally favorable survival to hospital discharge (Cerebral Performance Category 1 or 2) was determined. Outcomes in a historical comparison group were also evaluated. RESULTS: Sixty-two (86%) of 72 transported patients met emergency medical services transport criteria. Fifty-five (89%) of the 62 patients met criteria for continuing resuscitation on CCL arrival; 5 had return of spontaneous circulation, 50 received ECLS, and all 55 received coronary angiography. Forty-six (84%) of 55 patients had significant CAD, 35 (64%) of 55 had acute thrombotic lesions, and 46 (84%) of 55 had percutaneous coronary intervention with 2.7 ± 2.0 stents deployed per patient. The mean SYNTAX score was 29.4 ± 13.9. Twenty-six (42%) of 62 patients were discharged alive with Cerebral Performance Category 1 or 2 versus 26 (15.3%) of 170 in the historical comparison group (odds ratio: 4.0; 95% confidence interval: 2.08 to 7.7; p < 0.0001). CONCLUSIONS: Complex but treatable CAD was prevalent in patients with refractory OH VF/VT cardiac arrest who also met criteria for continuing resuscitation in the CCL. A systems approach using ECLS and reperfusion seemed to improve functionally favorable survival.

Outcomes of sudden cardiac arrest in a state-wide integrated resuscitation program: Results from the Minnesota Resuscitation Consortium.

BACKGROUND: Despite many advances in resuscitation science the outcomes of sudden cardiac arrest (SCA) remain poor. The Minnesota Resuscitation Consortium (MRC) is a statewide integrated resuscitation program, established in 2011, to provide standardized, evidence-based resuscitation and post-resuscitation care. The objective of this study is to assess the outcomes of a state-wide integrated resuscitation program. METHODS: We examined the trends in resuscitation metrics and outcomes in Minnesota since 2011 and compared these to the results from the national Cardiac Arrest Registry to Enhance Survival (CARES) program. Since 2011 MRC has expanded significantly providing service to >75% of Minnesota's population. RESULTS: A total of 5192 SCA occurred in counties covered by MRC from 2011 to 2014. In this period, bystander cardiopulmonary resuscitation (CPR) and use of hypothermia, automatic CPR device and impedance threshold device increased significantly (p<0.0001 for all). Compared to CARES, SCA cases in Minnesota were more likely to be ventricular fibrillation (31% vs. 23%, p<0.0001) but less likely to receive bystander CPR (33% vs. 39%, p<0.0001). Survival to hospital discharge with good or moderate cerebral performance (12% vs. 8%, p<0.0001), survival in SCA with a shockable rhythm (Utstein survival) (38% vs. 33%, p=0.0003) and Utstein survival with bystander CPR (44% vs. 37%, p=0.003) were greater in Minnesota than CARES. CONCLUSIONS: State-wide integration of resuscitation services in Minnesota was feasible. Survival rate after cardiac arrest is greater in Minnesota compared to the mean survival rate in CARES.

Minnesota Resuscitation Consortium's Advanced Perfusion and Reperfusion Cardiac Life Support Strategy for Out-of-Hospital Refractory Ventricular Fibrillation.

BACKGROUND: In 2015, the Minnesota Resuscitation Consortium (MRC) implemented an advanced perfusion and reperfusion life support strategy designed to improve outcome for patients with out-of-hospital refractory ventricular fibrillation/ventricular tachycardia (VF/VT). We report the outcomes of the initial 3-month period of operations. METHODS AND RESULTS: Three emergency medical services systems serving the Minneapolis-St. Paul metro area participated in the protocol. Inclusion criteria included age 18 to 75 years, body habitus accommodating automated Lund University Cardiac Arrest System (LUCAS) cardiopulmonary resuscitation (CPR), and estimated transfer time from the scene to the cardiac catheterization laboratory of ≤30 minutes. Exclusion criteria included known terminal illness, Do Not Resuscitate/Do Not Intubate status, traumatic arrest, and significant bleeding. Refractory VF/VT arrest was defined as failure to achieve sustained return of spontaneous circulation after treatment with 3 direct current shocks and administration of 300 mg of intravenous/intraosseous amiodarone. Patients were transported to the University of Minnesota, where emergent advanced perfusion strategies (extracorporeal membrane oxygenation; ECMO), followed by coronary angiography and primary coronary intervention (PCI), were performed, when appropriate. Over the first 3 months of the protocol, 27 patients were transported with ongoing mechanical CPR. Of these, 18 patients met the inclusion and exclusion criteria. ECMO was placed in 83%. Seventy-eight percent of patients had significant coronary artery disease with a high degree of complexity and 67% received PCI. Seventy-eight percent of patients survived to hospital admission and 55% (10 of 18) survived to hospital discharge, with 50% (9 of 18) achieving good neurological function (cerebral performance categories 1 and 2). No significant ECMO-related complications were encountered. CONCLUSIONS: The MRC refractory VF/VT protocol is feasible and led to a high functionally favorable survival rate with few complications.

Early Access to the Cardiac Catheterization Laboratory for Patients Resuscitated From Cardiac Arrest Due to a Shockable Rhythm: The Minnesota Resuscitation Consortium Twin Cities Unified Protocol.

BACKGROUND: In 2013 the Minnesota Resuscitation Consortium developed an organized approach for the management of patients resuscitated from shockable rhythms to gain early access to the cardiac catheterization laboratory (CCL) in the metro area of Minneapolis-St. Paul. METHODS AND RESULTS: Eleven hospitals with 24/7 percutaneous coronary intervention capabilities agreed to provide early (within 6 hours of arrival at the Emergency Department) access to the CCL with the intention to perform coronary revascularization for outpatients who were successfully resuscitated from ventricular fibrillation/ventricular tachycardia arrest. Other inclusion criteria were age >18 and <76 and presumed cardiac etiology. Patients with other rhythms, known do not resuscitate/do not intubate, noncardiac etiology, significant bleeding, and terminal disease were excluded. The primary outcome was survival to hospital discharge with favorable neurological outcome. Patients (315 out of 331) who were resuscitated from VT/VF and transferred alive to the Emergency Department had complete medical records. Of those, 231 (73.3%) were taken to the CCL per the Minnesota Resuscitation Consortium protocol while 84 (26.6%) were not taken to the CCL (protocol deviations). Overall, 197 (63%) patients survived to hospital discharge with good neurological outcome (cerebral performance category of 1 or 2). Of the patients who followed the Minnesota Resuscitation Consortium protocol, 121 (52%) underwent percutaneous coronary intervention, and 15 (7%) underwent coronary artery bypass graft. In this group, 151 (65%) survived with good neurological outcome, whereas in the group that did not follow the Minnesota Resuscitation Consortium protocol, 46 (55%) survived with good neurological outcome (adjusted odds ratio: 1.99; [1.07-3.72], P=0.03). CONCLUSIONS: Early access to the CCL after cardiac arrest due to a shockable rhythm in a selected group of patients is feasible in a large metropolitan area in the United States and is associated with a 65% survival rate to hospital discharge with a good neurological outcome.

Comparison of prehospital insertion success rates and time to insertion between standard endotracheal intubation and a supraglottic airway.

OBJECTIVE: To compare paramedic insertion success rates and time to insertion between standard ETI and a supraglottc airway device (King LTS-D™) in patients needing advanced airway management. METHODS: Between June 2008 and June 2009, consented paramedics from 4 EMS systems performed ETI or placed a King LTS-D according to a predetermined randomization calendar. Data collection occurred following each placement via telephone. Placement success (ability to ventilate to chest rise, absence of gastric sounds, presence of bilateral lung sounds, and when applicable, quantitative end-tidal CO(2) reading) was compared between treatment groups. Time to ventilation (time from airway device in hand ready to place to time of first successful ventilation) was also compared. RESULTS: A total of 213 patients in need of advanced airway management were treated during the study period, with 9 patients excluded from the analysis. The remaining 204 placements by 110 of the 272 consented paramedics were analyzed (median placements per paramedic=1; range=1-7). The overall placement success rate was virtually equal across the two groups (ETI=80.2%, King LTS-D=80.5%; p=0.97). The median time to placement between ETI and the King LTS-D was also not significantly different (ETI=19.5s vs. King LTS-D=20.0s; z=-0.25; p=0.80). CONCLUSION: In this study, no differences in placement success rate or time to insertion were detected between the King LTS-D and ETI.

Hospital response to a major freeway bridge collapse.

BACKGROUND: We describe the hospital system response to the Interstate 35W bridge collapse in Minneapolis into the Mississippi River on August 1, 2007, which resulted in 13 deaths and 127 injuries. Comparative analysis of response activities at the 3 hospitals that received critical or serious casualties is provided. METHODS: First-hand experiences of hospital physicians, issues identified in after-action reports, injury severity scores, and other relevant patient data were collected from the 3 hospitals that received seriously injured patients, including the closest hospitals to the collapse on each side of the river. RESULTS/DISCUSSION: Injuries were consistent with major acceleration/deceleration force injuries. The most critical patients arrived first at each hospital, suggesting appropriate prehospital triage. Capacity of the health care system was not overwhelmed and the involved hospitals generally reported an overresponse by staff. Communication and patient tracking problems occurred at all of the hospitals. Situational awareness was limited due to the scope of structural collapse and incomplete information from the scene. CONCLUSIONS: Hospitals were generally satisfied with their surge capacity and incident management plan activation. Issues such as communications, patient tracking, and staff overreporting that have been identified in past incidents also were problematic in this event. Hospitals will need to address deficiencies and build on successful actions to cope with future, potentially larger incidents.