Nicholas J. Johnson

Extracorporeal life support as rescue strategy for out-of-hospital and emergency department cardiac arrest.

BACKGROUND Extracorporeal life support (ECLS) has been utilized as a rescue strategy for patients with cardiac arrest unresponsive to conventional cardiopulmonary resuscitation. OBJECTIVE We sought to describe our institutions experience with implementation of ECLS for out-of-hospital and emergency department (ED) cardiac arrests. Our primary outcome was survival to hospital discharge. METHODS Consecutive patients placed on ECLS in the ED or within one hour of admission after out-of-hospital or ED cardiac arrest were enrolled at two urban academic medical centers in the United States from July 2007-April 2014. RESULTS During the study period, 26 patients were included. Average age was 40±15 years, 54% were male, and 42% were white. Initial cardiac rhythms were ventricular fibrillation or pulseless ventricular tachycardia in 42%. The average time from initial cardiac arrest to initiation of ECLS was 77 ± 51 min (range 12-180 min). ECLS cannulation was unsuccessful in two patients. Eighteen (69%) had complications related to ECLS, most commonly bleeding and ischemic events. Four patients (15%) survived to discharge, three of whom were neurologically intact at 6 months. CONCLUSION ECLS shows promise as a rescue strategy for refractory out-of-hospital or ED cardiac arrest but is not without challenges. Further investigations are necessary to refine the technique, patient selection, and ancillary therapeutics.

Practice characteristics of Emergency Department extracorporeal cardiopulmonary resuscitation (eCPR) programs in the United States: The current state of the art of Emergency Department extracorporeal membrane oxygenation (ED ECMO).

PURPOSE To characterize the current scope and practices of centers performing extracorporeal cardiopulmonary resuscitation (eCPR) on the undifferentiated patient with cardiac arrest in the emergency department. METHODS We contacted all US centers in January 2016 that had submitted adult eCPR cases to the Extracorporeal Life Support Organization (ELSO) registry and surveyed them, querying for programs that had performed eCPR in the Emergency Department (ED ECMO). Our objective was to characterize the following domains of ED ECMO practice: program characteristics, patient selection, devices and techniques, and personnel. RESULTS Among 99 centers queried, 70 responded. Among these, 36 centers performed ED ECMO. Nearly 93% of programs are based at academic/teaching hospitals. 65% of programs are less than 5 years old, and 60% of programs perform ≤3 cases per year. Most programs (90%) had inpatient eCPR or salvage ECMO programs prior to starting ED ECMO programs. The majority of programs do not have formal inclusion and exclusion criteria. Most programs preferentially obtain vascular access via the percutaneous route (70%) and many (40%) use mechanical CPR during cannulation. The most commonly used console is the Maquet Rotaflow(®). Cannulation is most often performed by cardiothoracic (CT) surgery, and nearly all programs (>85%) involve CT surgeons, perfusionists, and pharmacists. CONCLUSIONS Over a third of centers that submitted adult eCPR cases to ELSO have performed ED ECMO. These programs are largely based at academic hospitals, new, and have low volumes. They do not have many formal inclusion or exclusion criteria, and devices and techniques are variable.

Pediatric Intubation by Paramedics in a Large Emergency Medical Services System: Process, Challenges, and Outcomes

STUDY OBJECTIVE Pediatric intubation is a core paramedic skill in some emergency medical services (EMS) systems. The literature lacks a detailed examination of the challenges and subsequent adjustments made by paramedics when intubating children in the out-of-hospital setting. We undertake a descriptive evaluation of the process of out-of-hospital pediatric intubation, focusing on challenges, adjustments, and outcomes. METHODS We performed a retrospective analysis of EMS responses between 2006 and 2012 that involved attempted intubation of children younger than 13 years by paramedics in a large, metropolitan EMS system. We calculated the incidence rate of attempted pediatric intubation with EMS and county census data. To summarize the intubation process, we linked a detailed out-of-hospital airway registry with clinical records from EMS, hospital, or autopsy encounters for each child. The main outcome measures were procedural challenges, procedural success, complications, and patient disposition. RESULTS Paramedics attempted intubation in 299 cases during 6.3 years, with an incidence of 1 pediatric intubation per 2,198 EMS responses. Less than half of intubations (44%) were for patients in cardiac arrest. Two thirds of patients were intubated on the first attempt (66%), and overall success was 97%. The most prevalent challenge was body fluids obscuring the laryngeal view (33%). After a failed first intubation attempt, corrective actions taken by paramedics included changing equipment (33%), suctioning (32%), and repositioning the patient (27%). Six patients (2%) experienced peri-intubation cardiac arrest and 1 patient had an iatrogenic tracheal injury. No esophageal intubations were observed. Of patients transported to the hospital, 86% were admitted to intensive care and hospital mortality was 27%. CONCLUSION Pediatric intubation by paramedics was performed infrequently in this EMS system. Although overall intubation success was high, a detailed evaluation of the process of intubation revealed specific challenges and adjustments that can be anticipated by paramedics to improve first-pass success, potentially reduce complications, and ultimately improve clinical outcomes.

Post-resuscitation arterial oxygen and carbon dioxide and outcomes after out-of-hospital cardiac arrest

OBJECTIVE To determine if arterial oxygen and carbon dioxide abnormalities in the first 24h after return of spontaneous circulation (ROSC) are associated with increased mortality in adult out-of-hospital cardiac arrest (OHCA). METHODS We used data from the Resuscitation Outcomes Consortium (ROC), including adult OHCA with sustained ROSC ≥1h after Emergency Department arrival and at least one arterial blood gas (ABG) measurement. Among ABGs measured during the first 24h of hospitalization, we identified the presence of hyperoxemia (PaO2≥300mmHg), hypoxemia (PaO2<60mmHg), hypercarbia (PaCO2>50mmHg) and hypocarbia (PaCO2<30mmHg). We evaluated the associations between oxygen and carbon dioxide abnormalities and hospital mortality, adjusting for confounders. RESULTS Among 9186 OHCA included in the analysis, hospital mortality was 67.3%. Hyperoxemia, hypoxemia, hypercarbia, and hypocarbia occurred in 26.5%, 19.0%, 51.0% and 30.6%, respectively. Initial hyperoxemia only was not associated with hospital mortality (adjusted OR 1.10; 95% CI: 0.97-1.26). However, final and any hyperoxemia (1.25; 1.11-1.41) were associated with increased hospital mortality. Initial (1.58; 1.30-1.92), final (3.06; 2.42-3.86) and any (1.76; 1.54-2.02) hypoxemia (PaO2<60mmHg) were associated with increased hospital mortality. Initial (1.89; 1.70-2.10); final (2.57; 2.18-3.04) and any (1.85; 1.67-2.05) hypercarbia (PaCO2>50mmHg) were associated with increased hospital mortality. Initial (1.13; 0.90-1.41), final (1.19; 1.04-1.37) and any (1.01; 0.91-1.12) hypocarbia (PaCO2<30mmHg) were not associated with hospital mortality. CONCLUSIONS In the first 24h after ROSC, abnormal post-arrest oxygen and carbon dioxide tensions are associated with increased out of-hospital cardiac arrest mortality.

The association between hemoglobin concentration and neurologic outcome after cardiac arrest.

PURPOSE The purpose of the study is to determine the association between hemoglobin concentration (Hgb) and neurologic outcome in postarrest patients. METHODS We conducted a retrospective cohort study using the Penn Alliance for Therapeutic Hypothermia (PATH) cardiac arrest registry. Inclusion criteria were resuscitated cardiac arrest (inhospital or out of hospital) and an Hgb value recorded within 24 hours of return of spontaneous circulation. The primary outcome was favorable neurologic status at hospital discharge. Survival to hospital discharge was a secondary outcome. RESULTS There were 598 eligible patients from 21 hospitals. Patients with favorable neurologic outcome had significantly higher median Hgb in the first 2 hours (12.7 vs 10.5 g/dL; P<.001) and 6 hours (12.6 vs 10.6 g/dL; P<.001) postarrest. Controlling for age, pulseless rhythm, etiology, location of arrest, receipt of targeted temperature management, hematologic or metastatic malignancy, or preexisting renal insufficiency, there was a significant relationship between Hgb and neurologic outcome within the first 6 hours after arrest (odds ratio, 1.23; 95% confidence interval, 1.09-1.38) and survival to hospital discharge (odds ratio, 1.20; 95% confidence interval, 1.08-1.34). CONCLUSION Higher Hgb after cardiac arrest is associated with favorable neurologic outcome, particularly within the first 6 hours. It is unclear if this effect is due to impaired oxygen delivery or if Hgb is a marker for more severe illness.

Initial arterial carbon dioxide tension is associated with neurological outcome after resuscitation from cardiac arrest

STUDY OBJECTIVES To determine the relationships between partial pressure of arterial carbon dioxide (PaCO2), prescribed minute ventilation (MV), and neurologic outcome in patients resuscitated from cardiac arrest. METHODS This was a retrospective cohort study utilizing a multicenter database of adult patients with return of spontaneous circulation (ROSC) after cardiac arrest. The primary outcome was neurologic status at hospital discharge, defined by Cerebral Performance Category (CPC) score: CPC 1-2 was favorable, CPC 3-5 was poor. We compared rates of initial normocarbia (PaCO2 31-49mmHg) and mean sequential PaCO2 measurements obtained over the first 24h. We also assessed the influence of MV on the PaCO2 at initial, 6, 12, 18, and 24h after cardiac arrest using univariate linear regression. RESULTS One hundred and fourteen patients from 3 institutions met inclusion criteria. Overall, 46/114 (40.4%, 95% CI: 31.4-49.4%) patients survived to hospital discharge, and 33/114 (28.9%, 20.6-37.2%) had CPC 1-2 at the time of discharge. A total of 38.9% (95% CI: 29.9-47.9%) of patients had initial normocarbia; 43.2% (28.6-57.8%) of these patients were discharged with CPC 1-2, compared with 20.3% (10.8-29.8%) of dyscarbic patients. By 6h, neurologic outcomes were not significantly associated with PaCO2. Prescribed MV was not associated with PaCO2 at any time point with the exception of a weak correlation at hour 18. CONCLUSION Initial normocarbia was associated with favorable neurological outcome in patients resuscitated from cardiac arrest. This relationship was not seen at subsequent time points. There was no significant association between prescribed MV and PaCO2 or neurologic outcome.

ICU Emergencies Simulation Curriculum for Critical Care Fellows: The Difficult Airway

Introduction Management of airway emergencies is a core skill for critical care fellows. There is no standardized training mechanism for difficult airway management among critical care fellowships, although fellows frequently cite management of airway catastrophes as an area of educational need. Methods Three simulation cases that are each approximately 15 minutes in length are presented. The cases represent airway emergencies encountered in the intensive care unit consisting of angioedema, endotracheal tube dislodgement, and endotracheal tube occlusion. Incorporated into the scenarios are planned incidents of interpersonal conflict requiring negotiation by the learner during a crisis event. The case descriptions are complete, with learning objectives and critical actions as well as all necessary personnel briefs and required equipment. Results The cases were completed over multiple simulation sessions on different days by 11 first-year critical care fellows during the 2016–2017 academic year. All participants demonstrated improvement in self-perceived confidence in airway management skills. Discussion The cases were felt to be realistic and beneficial and led to perceived improvement in management of airway emergencies and leadership during crisis scenarios.

Ventilator Management and Respiratory Care after Cardiac Arrest: Oxygenation, Ventilation, Infection, and Injury

&NA; Return of spontaneous circulation after cardiac arrest results in a systemic inflammatory state called the post‐cardiac arrest syndrome, which is characterized by oxidative stress, coagulopathy, neuronal injury, and organ dysfunction. Perturbations in oxygenation and ventilation may exacerbate secondary injury after cardiac arrest and have been shown to be associated with poor outcome. Further, patients who experience cardiac arrest are at risk for a number of other pulmonary complications. Up to 70% of patients experience early infection after cardiac arrest, and the respiratory tract is the most common source. Vigilance for early‐onset pneumonia, as well as aggressive diagnosis and early antimicrobial agent administration are important components of critical care in this population. Patients who experience cardiac arrest are at risk for the development of ARDS. Risk factors include aspiration, pulmonary contusions (from chest compressions), systemic inflammation, and reperfusion injury. Early evidence suggests that they may benefit from ventilation with low tidal volumes. Meticulous attention to mechanical ventilation, early assessment and optimization of respiratory gas exchange, and therapies targeted at potential pulmonary complications may improve outcomes after cardiac arrest.