Supraglottic airway devices are associated with asphyxial physiology after prolonged CPR in patients with refractory Out-of-Hospital cardiac arrest presenting for extracorporeal cardiopulmonary resuscitation.

BACKGROUND: Multiple randomized clinical trials have compared specific airway management strategies during ACLS with conflicting results. However, patients with refractory cardiac arrest died in almost all cases without the availability of extracorporeal cardiopulmonary resuscitation (ECPR). Our aim was to determine if endotracheal intubation (ETI) was associated with improved outcomes compared to supraglottic airways (SGA) in patients with refractory cardiac arrest presenting for ECPR. METHODS: We retrospectively studied 420 consecutive adult patients with refractory out-of-hospital cardiac arrest due to shockable presenting rhythms presenting to the University of Minnesota ECPR program. We compared outcomes between patients receiving ETI (n = 179) and SGA (n = 204). The primary outcome was the pre-cannulation arterial PaO2 upon arrival to the ECMO cannulation center. Secondary outcomes included neurologically favorable survival to hospital discharge and eligibility for VA-ECMO based upon resuscitation continuation criteria applied upon arrival to the ECMO cannulation center. RESULTS: Patients receiving ETI had significantly higher median PaO2 (71 vs. 58 mmHg, p = 0.001), lower median PaCO2 (55 vs. 75 mmHg, p < 0.001), and higher median pH (7.03 vs. 6.93, p < 0.001) compared to those receiving SGA. Patients receiving ETI were also significantly more likely to meet VA-ECMO eligibility criteria (85% vs. 74%, p = 0.008). Of patients eligible for VA-ECMO, patients receiving ETI had significantly higher neurologically favorable survival compared to SGA (42% vs. 29%, p = 0.02). CONCLUSIONS: ETI was associated with improved oxygenation and ventilation after prolonged CPR. This resulted in increased rate of candidacy for ECPR and increased neurologically favorable survival to discharge with ETI compared to SGA.

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.

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.

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.

Bispectral index monitoring in helicopter emergency medical services patients.

Background. Many critically ill patients are given sedatives and paralytics to facilitate aeromedical transport. Bispectral index (BIS) monitoring is a computer-derived electroencephalography (EEG) analog currently used to monitor the level of awareness of sedated patients. It gives a score of 1-100, with 1 representing no brain function and 100 representing a completely alert patient. Objective. To evaluate whether critically ill patients are adequately sedated during aeromedical transport. Methods. This was a prospective, observational study of a convenience sample of critically ill patients transported by helicopter. All intubated patients who received sedatives and/or paralytics to facilitate transport were eligible for enrollment by the attending clinician. Prior to liftoff, a BIS sensor was applied to the patient's forehead. Minimum, maximum, and mean BIS index scores were recorded every minute during transport. Results. Forty-seven patients (57% male) were enrolled, with a median age of 60 years (interquartile range [IQR] 18-81, range 14 to 86 years). The median duration of monitoring was 15.0- minutes (IQR 6.0-26.0, range 2 to 33). The median BIS score was 54.6 (IQR 38.6-67.3, range 28 to 89.5). Only two patients (4.3%, 95% confidence interval [CI] 0.5% to 14.8%) had at least one BIS score greater than 85, the accepted threshold for recall. Conclusion. These results suggest that patients are adequately sedated during air medical transport.

Successful training of HEMS personnel in laryngeal mask airway and intubating laryngeal mask airway placement.

INTRODUCTION: To evaluate laryngeal mask airway (LMA) and intubating laryngeal mask airway (ILMA) placement by helicopter emergency medical services (HEMS) personnel after a comprehensive training program. METHODS: HEMS flight staff attended a didactic and manikin-based training session for both devices. After this training, they attempted LMA and ILMA placement in live, anesthetized patients in an operating room (OR). Outcome measures included placement success rates with the LMA, ILMA, and endotracheal intubation through the ILMA, time to ventilation, and time to intubation. Success rates and time to ventilation were compared using chi-squared and analysis of variance (ANOVA), respectively. Mean time to ventilation for the first and second placements of both devices was examined with repeated measures ANOVA. RESULTS: There was no difference in successful placement of the LMA compared with the ILMA (100% vs. 91%, P = .15). Ninety-five percent (19/20) of patients were successfully intubated through the ILMA. Time to intubation was 57.1 +/- 55 seconds (range, 20-240). Mean time to ventilation with either device did not differ significantly (36.8 +/- 17 vs. 38.05 +/- 20 seconds; P = .29). Mean time to ventilation for the first and second placement of either the LMA (P = .45) or the ILMA (P = .47) was not statistically different. CONCLUSION: Trained HEMS flight staff are capable of effectively placing the LMA and ILMA in the operating room after a comprehensive training protocol.

Does the ILMA make sense in HEMS?

As first reported by Brain(1) by the early 1980s, the laryngeal mask airway (LMA) represented a new approach to airway management. The LMA has been used to facilitate tracheal intubation by a variety of methods. In fact, the LMA has been used to intubate the patient with difficult tracheal access. A recent addition to this technique, the intubating laryngeal mask airway (ILMA), shown in Figure 1, first was proposed by Brain and coworkers in 1995.(1,2) Fig. 1. Components of the intubating laryngeal mask airway. An endotracheal tube may be passed through the airway tube. The ILMA incorporates the standard LMA cuff in sizes 3, 4, or 5, along with a metal airway tube and handle. The handle allows users to manipulate the device within the patient's airway. The airway tube component has a wider internal diameter and is shorter than the standard LMA tube. A silicone rubber bite block surrounds the upper portion of the stem.

Evaluation of active compression-decompression CPR in victims of out-of-hospital cardiac arrest.

OBJECTIVE--Active compression-decompression (ACD) cardiopulmonary resuscitation (CPR) appears to improve ventilation and coronary perfusion when compared with standard CPR. The objective was to evaluate potential benefits of this new CPR technique in patients with out-of-hospital cardiac arrest in St Paul, Minn. DESIGN--Ten-month, prospective, randomized parallel-group design. SETTING--St Paul, Minn, population 270,000. PATIENTS--All normothermic victims of nontraumatic cardiac arrest older than 8 years who received CPR. MAIN OUTCOME MEASURES--Return of spontaneous circulation, admission to the intensive care unit (ICU), return of baseline neurological function (alert and oriented to person, place, and time), survival to hospital discharge, survival to hospital discharge with return of baseline neurological function, and complications. RESULTS--Seventy-seven patients received standard CPR and 53 patients received ACD CPR. The mean emergency medical services call response interval was less than 3.5 minutes. When all patients were considered, a higher percentage of ACD CPR patients had a return of spontaneous circulation and were admitted to the ICU vs standard CPR (45% vs 31%, and 40% vs 26%, respectively), but these trends were not statistically significant (P < .10 and P < .10). No statistically significant differences were found between hospital discharge rates (12 [23%] of 53 for ACD CPR vs 13 [17%] of 77 for standard CPR), return to baseline neurological function (10 [19%] of 53 for ACD CPR vs 13 [17%] of 77 for standard CPR), or return to baseline neurological function at hospital discharge (nine [17%] of 53 for ACD CPR vs 12 [16%] of 77 for standard CPR). Return of spontaneous circulation, ICU admission, and neurological recovery in both CPR groups were highly correlated with downtime (time from collapse to emergency medical system personnel arrival to the scene in witnessed arrests). With less than 10 minutes' downtime, survival to the ICU was 59% (19/32) with ACD CPR and 33% (16/49) with standard CPR (P < .02), return to baseline neurological function was 31% (10/32) with ACD CPR and 20% (10/49) with standard CPR (P = .27), and hospital discharge rate was 38% (12/32) with ACD CPR and 20% (10/49) with standard CPR (P = .17). Complication rates in patients admitted to the hospital were similar in both groups. CONCLUSIONS--This study demonstrates that ACD CPR appears to be more effective than standard CPR in a well-defined subset of victims of out-of-hospital cardiac arrest during the critical early phases of resuscitation. Based on this study, a larger study should be performed to evaluate the potential long-term benefits of ACD CPR.

Complication rates for the esophageal obturator airway and endotracheal tube in the prehospital setting.

PURPOSE: The purpose of this study was to determine the complication rates associated with the use of the endotracheal tube (ET) and the use of the esophageal obturator airway/esophageal gastric tube airway (EOA/EGTA) during the treatment of patients with prehospital cardiac arrest. METHODS: A descriptive, quasi-experimental study of 509 consecutive adults, cardiac arrest patients was conducted. Patients were examined prospectively for airway intervention type and complications. Some patients were examined at their final destinations (field, morgue, funeral home), while other patients were examined by EMS providers in the field when airway adjuncts were switched. Also, airways were evaluated for complications by emergency physicians at destination emergency departments. RESULTS: The airway in use at the time of examination was the esophageal obturator airway (EOA) or esophageal gastric tube airway (EGTA) in 208 patients (40.1%); the ET (endotracheal tube) in 232 patients (45.6%); and an oral or nasopharyngeal airway in 47 patients (9.2%). Twenty-two patients (4.3%) had both an EOA/EGTA and an ET tube in place at the time of the examination. The survival rates were similar between the EOA/EGTA and the ET groups (28% and 32%, respectively). The complication rates overall also were similar, but the serious or potentially lethal complication rate was 3.3 times more common with the use of the EOA/EGTA than with the ET tube (8.7% versus 2.6%, respectively). CONCLUSIONS: The complication rate for the EOA/EGTA is unacceptably high, and careful thought must be given to its continued use.(ABSTRACT TRUNCATED AT 250 WORDS)