Survival for Nonshockable Cardiac Arrests Treated With Noninvasive Circulatory Adjuncts and Head/Thorax Elevation.

OBJECTIVES: Cardiac arrests remain a leading cause of death worldwide. Most patients have nonshockable electrocardiographic presentations (asystole/pulseless electrical activity). Despite well-performed basic and advanced cardiopulmonary resuscitation (CPR) interventions, patients with these presentations have always faced unlikely chances of survival. The primary objective was to determine if, in addition to conventional CPR (C-CPR), expeditious application of noninvasive circulation-enhancing adjuncts, and then gradual elevation of head and thorax, would be associated with higher likelihoods of survival following out-of-hospital cardiac arrest (OHCA) with nonshockable presentations. DESIGN: Using a prospective observational study design (ClinicalTrials.gov NCT05588024), patient data from the national registry of emergency medical services (EMS) agencies deploying the CPR-enhancing adjuncts and automated head/thorax-up positioning (AHUP-CPR) were compared with counterpart reference control patient data derived from the two National Institutes of Health clinical trials that closely monitored quality CPR performance. Beyond unadjusted comparisons, propensity score matching and matching of time to EMS-initiated CPR (TCPR) were used to assemble cohorts with corresponding best-fit distributions of the well-established characteristics associated with OHCA outcomes. SETTING: North American 9-1-1 EMS agencies. PATIENTS: Adult nontraumatic OHCA patients receiving 9-1-1 responses. INTERVENTIONS: In addition to C-CPR, study patients received the CPR adjuncts and AHUP (all U.S. Food and Drug Administration-cleared). MEASUREMENTS AND MAIN RESULTS: The median TCPR for both AHUP-CPR and C-CPR groups was 8 minutes. Median time to AHUP initiation was 11 minutes. Combining all patients irrespective of lengthier response intervals, the collective unadjusted likelihood of AHUP-CPR group survival to hospital discharge was 7.4% (28/380) vs. 3.1% (58/1,852) for C-CPR (odds ratio [OR], 2.46 [95% CI, 1.55-3.92]) and, after propensity score matching, 7.6% (27/353) vs. 2.8% (10/353) (OR, 2.84 [95% CI, 1.35-5.96]). Faster AHUP-CPR application markedly amplified odds of survival and neurologically favorable survival. CONCLUSIONS: These findings indicate that, compared with C-CPR, there are strong associations between rapid AHUP-CPR treatment and greater likelihood of patient survival, as well as survival with good neurological function, in cases of nonshockable OHCA.

Evaluation of an EMS-Based Community Paramedic Pilot Program to Reduce Frequency of 9-1-1 Calls among High Utilizers.

BACKGROUND: Many community paramedic interventions aim to reduce unnecessary emergency department visits among high utilizers of acute care, but fewer focus specifically on reducing summons for emergency medical services (EMS). We implemented an EMS-based pilot program that identified high utilizers of 9-1-1 and facilitated community paramedic outreach encounters to understand and address potentially unnecessary 9-1-1 calls. This study compares the pre- and post-intervention incidence rate of 9-1-1 calls among program participants. METHODS: This retrospective evaluation was conducted using pilot data from a single U.S. EMS agency that responds to approximately 100,000 9-1-1 calls annually. High utilizers, defined as individuals with ≥3 9-1-1 calls in 90 days, were identified for recruitment between February 1, 2019 and December 31, 2019. Community paramedics recruited participants via phone and then conducted home visits to assist them with navigation away from unnecessary 9-1-1 use. Dispatch data from September 1, 2018 to December 31, 2019 were used to compute the incidence rate of 9-1-1 calls per 30 person-days of observation before and after the initial home visits. RESULTS: Data from 108 program participants were analyzed. The majority were over the age of 50 (79%), and 33% completed more than one visit. Median person-days of observation before and after the initial home visit were 354 days and 132 days, respectively. Participants called 9-1-1 an average of 0.68 times per 30 person-days prior to the community paramedic intervention, and 0.51 times per 30 person-days after the intervention, which represents an overall mean decrease in 9-1-1 utilization of 25% (p < 0.001). Although a decrease in 9-1-1 utilization was observed in the majority of participants, the 9-1-1 call rate increased in 29% of participants. No statistically significant changes in 9-1-1 use were observed in participants who received more than one home visit or who were in the highest quartile of 9-1-1 use prior to the intervention. CONCLUSION: This pilot work demonstrates the feasibility of an EMS-based, community paramedic-only intervention to reduce unnecessary 9-1-1 calls and suggests that some modest reductions in EMS use may be achievable by dispatching community paramedics to conduct home visits with frequent users of 9-1-1.

Emergency Medical Services Provider Perspectives on Pediatric Calls: A Qualitative Study.

Objective: Previous research indicates that 9-1-1 response to incidents involving children is particularly distressing for emergency medical services (EMS) clinicians. This qualitative study was conducted to increase understanding about the difficulties of responding to pediatric calls and to obtain information about how organizations can better support EMS providers in managing potentially difficult calls. Methods: Paramedics and emergency medical technicians from a single U.S. ambulance service were invited to participate in focus groups about responding to 9-1-1 calls involving pediatric patients. A total of 17 providers from both rural and metro service regions participated in six focus groups held in community meeting spaces. A semi-structured focus group guide was used to explore (1) elements that make pediatric calls difficult, (2) pre-arrival preparation practices, (3) experiences with coping after difficult pediatric calls, and (4) perspectives about offered and desired resources or support. Focus groups were audio recorded and transcripts were analyzed using standard coding, memoing, and content analysis methods in qualitative analysis software (NVivo). Results: Responses about elements that make pediatric calls difficult were organized into the following themes: (1) special social value of children, (2) clinical difficulties with pediatric patients, (3) added acuity to already challenging calls, (4) caregivers as secondary patient, and (5) identifying with patient or patient's family. Pre-arrival preparation methods included mental or verbal review of hypothetical scenarios and refocusing nerves or emotions back to the technical aspect of the job. Participants described using available resources that largely took the form of social support. Suggestions for additional resources included: increased opportunities for external feedback; more frequent pediatric clinical training; institutionalization of recovery time after difficult calls; and improved storage and labeling of pediatric equipment. Conclusions: This study provides qualitative data about the difficulties of responding to pediatric calls and resources needed to support clinicians. Findings from this study can be used to guide EMS leaders in designing and implementing institutional initiatives to enhance training and support for prehospital clinicians providing care to children.

Use of an impedance threshold device to treat severe hypotension in a pregnant woman: case report and review of the literature.

BACKGROUND: Impedance threshold device technology harnesses the patient's normal physiological mechanisms to increase circulation during hypotensive crises. We report the first clinical use of one version of this device on a spontaneously breathing hypotensive pregnant woman. OBJECTIVE: The objective of our study was to report this case to help Emergency Medical Service rescue personnel to noninvasively treat hypotensive but conscious spontaneously breathing patients. CASE REPORT: A 28-year-old woman who was 21 weeks pregnant developed frank syncope at home but recovered spontaneously. When Emergency Medical Service paramedics arrived, her initial blood pressure and heart rate were 115/80 mm Hg and 125 beats/min, respectively. She suddenly complained of feeling anxious and developed profound bradycardia and hypotension, followed by 20 s of asystole. An impedance threshold device (ResQGARD™) with -7 cmH2O resistance to inspiration was rapidly applied using a facemask. After four spontaneous breaths, blood pressure increased from 62/40 mm Hg to 106/66 mm Hg. She was hemodynamically stable thereafter. CONCLUSIONS: In this case report, the multiple physiological effects of inspiration through -7 cmH2O resistance helped this pregnant hypotensive patient to rapidly and noninvasively restore adequate perfusion and reduced the duration of her hypotensive episode. To our knowledge, this is the first report of this technology in a pregnant hypotensive but spontaneously breathing patient.

Implementation of a mechanical chest compression device as standard equipment in a large metropolitan ambulance service.

BACKGROUND: We will describe the implementation of the LUCAS™1 chest compression device as standard equipment in the treatment of cardiac arrest across a large ambulance service and provide descriptive data on device-treated arrests and provider experience during the initial 2 years of use. METHODS: Provider training and deployment of 38 devices occurred in our 70-vehicle, 400-provider ambulance service within 3 months. A retrospective case series of device-eligible out-of-hospital cardiac arrests occurring between May 2008 and June 2010 was analyzed. Clinical data were extracted from an electronic prehospital patient care record and information on provider experience with the device was collected via online survey. RESULTS: LUCAS™1 was used in 79% of resuscitation attempts (498 of 631). Primary reasons for nonuse were resuscitation of limited duration and extreme body size. Return of spontaneous circulation (ROSC) was documented in 35% and 41% of device- and non-device-treated arrests, respectively (p = 0.31), but among arrests where time from arrival at patient to discontinuation of cardiopulmonary resuscitation was >5 min, the rates were 26% and 24%, respectively (p = 0.78). CONCLUSIONS: A large ambulance service in the United States initiated standard use of a mechanical compression device within 3 months. In an applied setting, the LUCAS™1 device fits most patients and was well received by prehospital providers. Resuscitation of limited duration due to early death or early ROSC frequently precludes device use, and this has important implications for evaluating the association between device use and ROSC in observational settings.

Take Heart America: A comprehensive, community-wide, systems-based approach to the treatment of cardiac arrest.

OBJECTIVES: To determine out-of-hospital cardiac arrest survival rates before and after implementation of the Take Heart America program (a community-based initiative that sequentially deployed all of the most highly recommended 2005 American Heart Association resuscitation guidelines in an effort to increase out-of-hospital cardiac arrest survival). PATIENTS: Out-of-hospital cardiac arrest patients in Anoka County, MN, and greater St. Cloud, MN, from November 2005 to June 2009. INTERVENTIONS: Two sites in Minnesota with a combined population of 439,692 people (greater St. Cloud and Anoka County) implemented: 1) widespread cardiopulmonary resuscitation and automated external defibrillator skills training in schools and businesses; 2) retraining of all emergency medical services personnel in methods to enhance circulation, including minimizing cardiopulmonary resuscitation interruptions, performing cardiopulmonary resuscitation before and after single-shock defibrillation, and use of an impedance threshold device; 3) additional deployment of automated external defibrillators in schools and public places; and 4) protocols for transport to and treatment by cardiac arrest centers for therapeutic hypothermia, coronary artery evaluation and treatment, and electrophysiological evaluation. MEASUREMENTS AND MAIN RESULTS: More than 28,000 people were trained in cardiopulmonary resuscitation and automated external defibrillator use in the two sites. Bystander cardiopulmonary resuscitation rates increased from 20% to 29% (p = .086, odds ratio 1.7, 95% confidence interval 0.96-2.89). Three cardiac arrest centers were established, and hypothermia therapy for admitted out-of-hospital cardiac arrest victims increased from 0% to 45%. Survival to hospital discharge for all patients after out-of-hospital cardiac arrest in these two sites improved from 8.5% (nine of 106, historical control) to 19% (48 of 247, intervention phase) (p = .011, odds ratio 2.60, confidence interval 1.19-6.26). A financial analysis revealed that the cardiac arrest centers concept was financially feasible, despite the costs associated with high-quality postresuscitation care. CONCLUSIONS: The Take Heart America program doubled cardiac arrest survival when compared with historical controls. Study of the feasibility of generalizing this approach to larger cities, states, and regions is underway.

Rationale and Strategies for Development of an Optimal Bundle of Management for Cardiac Arrest.

OBJECTIVES: To construct a highly detailed yet practical, attainable roadmap for enhancing the likelihood of neurologically intact survival following sudden cardiac arrest. DESIGN SETTING AND PATIENTS: Population-based outcomes following out-of-hospital cardiac arrest were collated for 10 U.S. counties in Alaska, California, Florida, Ohio, Minnesota, Utah, and Washington. The 10 identified emergency medical services systems were those that had recently reported significant improvements in neurologically intact survival after introducing a more comprehensive approach involving citizens, hospitals, and evolving strategies for incorporating technology-based, highly choreographed care and training. Detailed inventories of in-common elements were collated from the ten 9-1-1 agencies and assimilated. For reference, combined averaged outcomes for out-of-hospital cardiac arrest occurring January 1, 2017, to February 28, 2018, were compared with concurrent U.S. outcomes reported by the well-established Cardiac Arrest Registry to Enhance Survival. INTERVENTIONS: Most commonly, interventions and components from the ten 9-1-1 systems consistently included extensive public cardiopulmonary resuscitation training, 9-1-1 system-connected smart phone applications, expedited dispatcher procedures, cardiopulmonary resuscitation quality monitoring, mechanical cardiopulmonary resuscitation, devices for enhancing negative intrathoracic pressure regulation, extracorporeal membrane oxygenation protocols, body temperature management procedures, rapid cardiac angiography, and intensive involvement of medical directors, operational and quality assurance officers, and training staff. MEASUREMENTS AND MAIN RESULTS: Compared with Cardiac Arrest Registry to Enhance Survival (n = 78,704), the cohorts from the 10 emergency medical services agencies examined (n = 2,911) demonstrated significantly increased likelihoods of return of spontaneous circulation (mean 37.4% vs 31.5%; p < 0.001) and neurologically favorable hospital discharge, particularly after witnessed collapses involving bystander cardiopulmonary resuscitation and shockable cardiac rhythms (mean 10.7% vs 8.4%; p < 0.001; and 41.6% vs 29.2%; p < 0.001, respectively). CONCLUSIONS: The likelihood of neurologically favorable survival following out-of-hospital cardiac arrest can improve substantially in communities that conscientiously and meticulously introduce a well-sequenced, highly choreographed, system-wide portfolio of both traditional and nonconventional approaches to training, technologies, and physiologic management. The commonalities found in the analyzed systems create a compelling case that other communities can also improve out-of-hospital cardiac arrest outcomes significantly by conscientiously exploring and adopting similar bundles of system organization and care.

Minnesota Heart Safe Communities: Are community-based initiatives increasing pre-ambulance CPR and AED use?

AIM: Implementation research that describes how successfully resuscitation guidelines are translated into practice are lacking. We examined whether recent community-based initiatives being conducted as part of the Minnesota Heart Safe (HS) Communities program increase the delivery of CPR and use of automated external defibrillators (AED) by bystanders and first responders prior to ambulance arrival. METHODS: Non-EMS witnessed out-of-hospital cardiac arrests (OHCA) with presumed cardiac etiology treated by a single ambulance service in 2013-2015 were studied. Data were obtained from the Minnesota HS program and the Cardiac Arrest Registry to Enhance Survival (CARES) Surveillance Registry. Pre-ambulance CPR and AED use within HS communities before and after completion of the program were compared. RESULTS: As of July 2016, 17 Minnesota communities within the ambulance service area had achieved HS designation and 294 OHCAs that occurred in these communities met inclusion criteria for analysis (120 before HS designation, 174 after). CPR was initiated by bystanders or first responders prior to ambulance arrival in 83% of OHCA events that occurred before HS designation and in 95% of events that occurred after designation (OR=4.23 [1.80-9.98]). Pre-ambulance AED use increased from 63% to 77% after the community intervention (OR=1.94 [1.16-3.24]). Overall unadjusted survival to hospital discharge increased slightly after HS designation, but this difference was not statistically significant (17% vs 20%, p=0.32). CONCLUSION: Implementation of the Heart Safe program in communities within our ambulance service area in Minnesota has increased use of CPR and AEDs by bystanders and first responders prior to ambulance arrival.

Use of intrathoracic pressure regulation therapy in breathing patients for the treatment of hypotension secondary to trauma.

BACKGROUND: Intrathoracic pressure regulation (IPR) therapy has been shown to increase blood pressure in hypotensive patients. The potential value of this therapy in patients with hypotension secondary to trauma with bleeding is not well understood. We hypothesized that IPR would non-invasively and safely enhance blood pressure in spontaneously breathing patients with trauma-induced hypotension. METHODS: This prospective observational cohort study assessed vital signs from hypotensive patients with a systolic blood pressure (SBP) ≤90 mmHg secondary to trauma treated with IPR (ResQGARD™, ZOLL Medical) by pre-hospital emergency medical personnel in three large US metropolitan areas. Upon determination of hypotension, facemask-based IPR was initiated as long as bleeding was controlled. Vital signs were recorded before, during, and after IPR. An increased SBP with IPR use was the primary study endpoint. Device tolerance and ease of use were also reported. RESULTS: A total of 54 patients with hypotension secondary to trauma were treated from 2009 to 2016. The mean ± SD SBP increased from 80.9 ± 12.2 mmHg to 106.6 ± 19.2 mmHg with IPR (p < 0.001) and mean arterial pressures (MAP) increased from 62.2 ± 10.5 mmHg to 81.9 ± 16.6 mmHg (p < 0.001). There were no significant changes in mean heart rate or oxygen saturation. Approximately 75% of patients reported moderate to easy tolerance of the device. There were no safety concerns or reported adverse events. CONCLUSIONS: These findings support the use of IPR to treat trauma-induced hypotension as long as bleeding has been controlled.

Prehospital Lactate Measurement by Emergency Medical Services in Patients Meeting Sepsis Criteria.

INTRODUCTION: We aimed to pilot test the delivery of sepsis education to emergency medical services (EMS) providers and the feasibility of equipping them with temporal artery thermometers (TATs) and handheld lactate meters to aid in the prehospital recognition of sepsis. METHODS: This study used a convenience sample of prehospital patients meeting established criteria for sepsis. Paramedics received education on systemic inflammatory response syndrome (SIRS) criteria, were trained in the use of TATs and hand-held lactate meters, and enrolled patients who had a recent history of infection, met ≥ 2 SIRS criteria, and were being transported to a participating hospital. Blood lactate was measured by paramedics in the prehospital setting and again in the emergency department (ED) via usual care. Paramedics entered data using an online database accessible at the point of care. RESULTS: Prehospital lactate values obtained by paramedics ranged from 0.8 to 9.8 mmol/L, and an elevated lactate (i.e. ≥ 4.0) was documented in 13 of 112 enrolled patients (12%). The unadjusted correlation of prehospital and ED lactate values was 0.57 (p< 0.001). The median interval between paramedic assessment of blood lactate and the electronic posting of the ED-measured lactate value in the hospital record was 111 minutes. Overall, 91 patients (81%) were hospitalized after ED evaluation, 27 (24%) were ultimately diagnosed with sepsis, and 3 (3%) died during hospitalization. Subjects with elevated prehospital lactate were somewhat more likely to have been admitted to the intensive care unit (23% vs 15%) and to have been diagnosed with sepsis (38% vs 22%) than those with normal lactate levels, but these differences were not statistically significant. CONCLUSION: In this pilot, EMS use of a combination of objective SIRS criteria, subjective assessment of infection, and blood lactate measurements did not achieve a level of diagnostic accuracy for sepsis that would warrant hospital prenotification and committed resources at a receiving hospital based on EMS assessment alone. Nevertheless, this work provides an early model for increasing EMS awareness and the implementation of novel devices that may enhance the prehospital assessment for sepsis. Additional translational research studies with larger numbers of patients and more robust methods are needed.

Awakening after cardiac arrest and post resuscitation hypothermia: are we pulling the plug too early?

BACKGROUND: Time to awakening after out-of-hospital cardiac arrest (OHCA) and post-resuscitation therapeutic hypothermia (TH) varies widely. We examined the time interval from when comatose OHCA patients were rewarmed to 37°C to when they showed definitive signs of neurological recovery and tried to identify potential predictors of awakening. METHODS: With IRB approval, a retrospective case study was performed in OHCA patients who were comatose upon presentation to a community hospital during 2006-2010. They were treated with TH (target of 33°C) for 24h, rewarmed, and discharged alive. Comatose patients were generally treated medically after TH for at least 48h before any decision to withdraw supportive care was made. Pre-hospital TH was not used. Data are expressed as medians and interquartile range. RESULTS: The 89 patients treated with TH in this analysis were divided into three groups based upon the time between rewarming to 37°C and regaining consciousness. The 69 patients that regained consciousness in ≤48h after rewarming were termed "early-awakeners". Ten patients regained consciousness 48-72h after rewarming and were termed "intermediate-awakeners". Ten patients remained comatose and apneic >72h after rewarming but eventually regained consciousness; they were termed "late-awakeners". The ages for the early, intermediate and late awakeners were 56 [49,65], 62 [48,74], and 58 [55,65] years, respectively. Nearly 67% were male. Following rewarming, the time required to regain consciousness for the early, intermediate and late awakeners was 9 [2,18] (range 0-47), 60.5 [56,64.5] (range 49-71), and 126 [104,151]h (range 73-259), respectively. Within 90 days of hospital admission, favorable neurological function based on a Cerebral Performance Category (CPC) score of 1 or 2 was reported in 67/69 early, 10/10 intermediate, and 8/10 late awakeners. CONCLUSION: Following OHCA and TH, arbitrary withdrawal of life support <48h after rewarming may prematurely terminate life in many patients with the potential for full neurological recovery. Additional clinical markers that correlate with late awakening are needed to better determine when withdrawal of support is appropriate in OHCA patients who remain comatose >48h after rewarming.

Assessment of CPR interruptions from transthoracic impedance during use of the LUCAS™ mechanical chest compression system.

BACKGROUND: Quality of cardiopulmonary resuscitation (CPR) is a key determinant of outcome following out-of-hospital cardiac arrest (OHCA). Recent evidence shows manual chest compressions are typically too shallow, interruptions are frequent and prolonged, and incomplete release between compressions is common. Mechanical chest compression systems have been developed as adjuncts for CPR but interruption of CPR during their use is not well documented. AIM: Analyze interruptions of CPR during application and use of the LUCAS™ chest compression system. METHODS: 54 LUCAS 1 devices operated on compressed air, deployed in 3 major US emergency medical services systems, were used to treat patients with OHCA. Electrocardiogram and transthoracic impedance data from defibrillator/monitors were analyzed to evaluate timing of CPR. Separately, providers estimated their CPR interruption time during application of LUCAS, for comparison to measured application time. RESULTS: In the 32 cases analyzed, compressions were paused a median of 32.5s (IQR 25-61) to apply LUCAS. Providers' estimates correlated poorly with measured pause length; pauses were often more than twice as long as estimated. The average device compression rate was 104/min (SD 4) and the average compression fraction (percent of time compressions were occurring) during mechanical CPR was 0.88 (SD 0.09). CONCLUSIONS: Interruptions in chest compressions to apply LUCAS can be <20s but are often much longer, and users do not perceive pause time accurately. Therefore, we recommend better training on application technique, and implementation of systems using impedance data to give users objective feedback on their mechanical chest compression device use.

Implementing the 2005 American Heart Association Guidelines improves outcomes after out-of-hospital cardiac arrest.

OBJECTIVE: The purpose of the study was to determine whether applying highly recommended changes in the 2005 American Heart Association (AHA) Guidelines would improve outcomes after out-of-hospital cardiac arrest. BACKGROUND: In 2005, AHA recommended multiple ways to improve circulation during cardiopulmonary resuscitation (CPR). METHODS: Conglomerate quality assurance data were analyzed during prospective implementation of the 2005 AHA Guidelines in five emergency medical services (EMS) systems. All EMS personnel were trained in the key new aspects of the 2005 AHA Guidelines, including use of an impedance threshold device. The primary outcome was survival to hospital discharge. Secondary outcomes were return of spontaneous circulation (ROSC), survival by initial cardiac arrest rhythm, and the cerebral performance category (CPC) score at hospital discharge. RESULTS: There were 1,605 patients in the intervention group and 1,641 patients in the control group. Demographics, the rate of bystander CPR, and time from the 911 call for help to arrival of EMS personnel were similar between groups. Survival to hospital discharge was 10.1% in the control group versus 13.1% in the intervention group (P = .007). For patients with a presenting rhythm of ventricular fibrillation/ventricular tachycardia, survival to discharge was 20% in controls versus 32.3% in the intervention group (P <.001). Survival to discharge with a CPC classification of 1 or 2 was 33.3% (10/30) in the control versus 59.6% (31/52) in the intervention group (P = .038). CONCLUSIONS: Compared with controls, patients with out-of-hospital cardiac arrest treated with a renewed emphasis on improved circulation during CPR had significantly higher neurologically intact hospital discharge rates.