Brian D. Mahoney

Standard cardiopulmonary resuscitation versus active compression-decompression cardiopulmonary resuscitation with augmentation of negative intrathoracic pressure for out-of-hospital cardiac arrest: a randomised trial

BACKGROUND Active compression-decompression cardiopulmonary resuscitation (CPR) with decreased intrathoracic pressure in the decompression phase can lead to improved haemodynamics compared with standard CPR. We aimed to assess effectiveness and safety of this intervention on survival with favourable neurological function after out-of-hospital cardiac arrest. METHODS In our randomised trial of 46 emergency medical service agencies (serving 2·3 million people) in urban, suburban, and rural areas of the USA, we assessed outcomes for patients with out-of-hospital cardiac arrest according to Utstein guidelines. We provisionally enrolled patients to receive standard CPR or active compression-decompression CPR with augmented negative intrathoracic pressure (via an impedance-threshold device) with a computer-generated block randomisation weekly schedule in a one-to-one ratio. Adults (presumed age or age ≥18 years) who had a non-traumatic arrest of presumed cardiac cause and met initial and final selection criteria received designated CPR and were included in the final analyses. The primary endpoint was survival to hospital discharge with favourable neurological function (modified Rankin scale score of ≤3). All investigators apart from initial rescuers were masked to treatment group assignment. This trial is registered with ClinicalTrials.gov, number NCT00189423. FINDINGS 2470 provisionally enrolled patients were randomly allocated to treatment groups. 813 (68%) of 1201 patients assigned to the standard CPR group (controls) and 840 (66%) of 1269 assigned to intervention CPR received designated CPR and were included in the final analyses. 47 (6%) of 813 controls survived to hospital discharge with favourable neurological function compared with 75 (9%) of 840 patients in the intervention group (odds ratio 1·58, 95% CI 1·07-2·36; p=0·019]. 74 (9%) of 840 patients survived to 1 year in the intervention group compared with 48 (6%) of 813 controls (p=0·03), with equivalent cognitive skills, disability ratings, and emotional-psychological statuses in both groups. The overall major adverse event rate did not differ between groups, but more patients had pulmonary oedema in the intervention group (94 [11%] of 840) than did controls (62 [7%] of 813; p=0·015). INTERPRETATION On the basis of our findings showing increased effectiveness and generalisability of the study intervention, active compression-decompression CPR with augmentation of negative intrathoracic pressure should be considered as an alternative to standard CPR to increase long-term survival after cardiac arrest. FUNDING US National Institutes of Health grant R44-HL065851-03, Advanced Circulatory Systems.

The Public Access Defibrillation (PAD) trial: study design and rationale.

The PAD Trial is a prospective, multicenter, randomized clinical study testing whether volunteer, non-medical responders can improve survival from out-of-hospital cardiac arrest (OOH-CA) by using automated external defibrillators (AEDs). These lay volunteers, who have no traditional responsibility to respond to a medical emergency as part of their primary job description, will form part of a comprehensive, integrated community approach to the treatment of OOH-CA. The study is being conducted at 24 field centers in the United States and Canada. Approximately 1000 community units (e.g. apartment or office buildings, gated communities, sports facilities, senior centers, shopping malls, etc.) were randomized to treatment by trained laypersons who will provide either cardiopulmonary resuscitation (CPR) alone or CPR plus use of an AED, while awaiting arrival of the communitys emergency medical services responders. The primary endpoint is the number of OOH-CA victims who survive to hospital discharge. Secondary endpoints include neurological status, health-related quality of life (HRQL), cost, and cost-effectiveness. Data collection will last approximately 15 months and is expected to be completed in September 2003.

Efficacy of pneumatic trousers in refractory prehospital cardiopulmonary arrest

Persons refractory to early application of advanced cardiac life support have a dismal prognosis. New modalities are needed to treat this almost universally lethal condition. We have evaluated pneumatic trousers in the treatment of refractory cardiopulmonary arrest. To date 136 patients have been entered into this controlled, prospective, randomized study. All patients were more than 20 years old and in cardiac arrest of apparent cardiac etiology. Patients were excluded if they had arrested secondary to trauma or overdose, or if an IV could not be started. In addition, patients had to be refractory to therapies included in our paramedic standing orders. If at the end of these standing orders the patient remained in arrest, he was entered into the study and pneumatic trousers were applied or not according to a randomized list. The attempted resuscitation was then continued with no other preset variables. The resuscitation and discharge rates for the control group were 21% and 4%, respectively. With pneumatic trousers, resuscitation increased to 33%, and discharge to 9%. The control group in ventricular fibrillation (VF) had a 27% resuscitation rate and a 5% discharge rate. The pneumatic trousers group with VF had a 35% resuscitation rate and a 12% discharge rate. In pulseless idioventricular rhythm (PIVR), the control group had a 0% resuscitation rate and a 0% discharge rate. In marked contrast, for PIVR the pneumatic trousers group had a 35% resuscitation rate and a 9% discharge rate. The control group in asystole (AS) had a 25% resuscitation rate and a 0% discharge rate. The pneumatic trousers group in AS had a 27% resuscitation rate and a 0% discharge rate. The improvement in resuscitation rate with pneumatic trousers was statistically significant only for the initial rhythm of PIVR (P less than .05). The pneumatic trousers improved resuscitation and discharge rates for refractory VF, but not to a statistically significant degree. These somewhat enhanced resuscitation and discharge rates with the pneumatic trousers make it an adjunct to be considered in refractory arrest.

Factors Influencing Hospital Transport of Patients in Continuing Cardiac Arrest

STUDY OBJECTIVE Prior research has established the futility of continued resuscitation efforts for patients in cardiac arrest who fail to respond to out-of-hospital advanced cardiac life support. Determination of both medical and nonmedical factors resulting in the transport of patients in continuing cardiac arrest to the hospital may encourage the development of new systems or strategies to increase the appropriateness of these transports. METHODS The attending paramedic completed a prospective survey after unsuccessful resuscitation efforts in our urban, hospital-based, two-tier emergency medical services (EMS) system. All nontraumatic adult arrests were included unless they were clearly noncardiac in nature. RESULTS Paramedics responded to 259 cardiac arrests between September 12, 1996, and April 31, 1997. Seventy-nine patients were pronounced dead without resuscitation efforts. Of the remaining 180 patients, 44 had return of spontaneous circulation and were transported to the hospital, 68 were pronounced dead in the field, and 68 were transported to the hospital in continuing cardiac arrest. The 68 patients transported while in cardiac arrest are the focus of this study. Rare problems with field termination were identified. Reasons for transport of the 68 patients in continuing cardiac arrest included arrest in ambulance or going to ambulance (n = 6), arrest in a public place (n = 17), environmental factors (n = 6), road hazard to paramedics (n = 1), possible reversible cause (n = 4), persistent ventricular dysrhythmia (n = 5), no intravenous access (n = 5), airway difficulties (n = 5), family unable to accept field termination (n = 3), cultural or language barrier (n = 1), EMS physician ordered transport (n = 1), and obesity (n = 1). A protocol allowing pronouncement of death in the ambulance and transport of the body to a designated area could have prevented lights-and-siren transport to the emergency department in 24 of the 68 cases. CONCLUSION Factors other than medical ones often influence the decision to transport patients in continuing cardiac arrest. In our urban system, physician, medical examiner, and paramedic education and protocols were needed to aid decision-making in this situation.

Treatment of non-traumatic out-of-hospital cardiac arrest with active compression decompression cardiopulmonary resuscitation plus an impedance threshold device

BACKGROUND A recent out-of-hospital cardiac arrest (OHCA) clinical trial showed improved survival to hospital discharge (HD) with favorable neurologic function for patients with cardiac arrest of cardiac origin treated with active compression decompression cardiopulmonary resuscitation (CPR) plus an impedance threshold device (ACD+ICD) versus standard (S) CPR. The current analysis examined whether treatment with ACD+ITD is more effective than standard (S-CPR) for all cardiac arrests of non-traumatic origin, regardless of the etiology. METHODS This is a secondary analysis of data from a randomized, prospective, multicenter, intention-to-treat, OHCA clinical trial. Adults with presumed non-traumatic cardiac arrest were enrolled and followed for one year post arrest. The primary endpoint was survival to hospital discharge (HD) with favorable neurologic function (Modified Rankin Scale score ≤ 3). RESULTS Between October 2005 and July 2009, 2738 patients were enrolled (S-CPR=1335; ACD+ITD=1403). Survival to HD with favorable neurologic function was greater with ACD+ITD compared with S-CPR: 7.9% versus 5.7%, (OR 1.42, 95% CI 1.04, 1.95, p=0.027). One-year survival was also greater: 7.9% versus 5.7%, (OR 1.43, 95% CI 1.04, 1.96, p=0.026). Nearly all survivors in both groups had returned to their baseline neurological function by one year. Major adverse event rates were similar between groups. CONCLUSIONS Treatment of out-of-hospital non-traumatic cardiac arrest patients with ACD+ITD resulted in a significant increase in survival to hospital discharge with favorable neurological function when compared with S-CPR. A significant increase survival rates was observed up to one year after arrest in subjects treated with ACD+ITD, regardless of the etiology of the cardiac arrest.

Emergency twist drill trephination.

We have used the rapid progression of post-traumatic uncal herniation in spite of intensive medical therapy as the indication for twist drill trephination in the emergency department. During a 54-month period, 51 trephinations were performed on 41 patients. The trephine was placed through the temporal bone ipsilateral to the dilated pupil, and the dura mater was opened to allow partial evacuation of the hematoma. All patients subsequently underwent craniotomy, autopsy, and/or cerebral computed tomography (CT). The trephination was diagnostically accurate for the absence or presence of an extracerebral hematoma in 42 of 51 trephinations (82%). In 6 of these cases the dilated pupil responded to partial hematoma evacuation by decreasing in size. In 3 of the 6 there was a marked overall improvement in neurological status subsequent to trephination. These 3 patients later recovered to an independent functional state. Only 23 of these 41 patients (56%) with herniation profiles actually had significant extracerebral hematomas. This fact emphasizes the inadvisability of taking this type of patient directly to the operating room without a diagnostic study. A rapidly performed CT scan is the obvious first choice. However, if there is any delay in obtaining this study or when uncal herniation occurs rapidly, a twist drill trephination can be of value in diagnosing the absence or presence of a treatable extracerebral hematoma. There were no complications related to this procedure in this group.

Feasibility of paramedic treatment and referral of minor illnesses and injuries

Background. Approximately 40% of Hennepin County Medical Centers (HCMCs) ambulance runs are for minor medical conditions as defined by billing criteria [“ALS minor,” i.e., no advanced life support (ALS) procedures done in the field]. Current metropolitan guidelines mandate that all such patients must be transported to a hospital unless they refuse this service. It has been proposed that some patients with minor medical conditions could be better served by treatment in the field by paramedics and referred to a clinic or hospital for early follow-up care. It is proposed that this approach would save costs and improve paramedic availability for patients with more serious conditions. Objective. To evaluate the feasibility and safety of implementing such a program by identifying high-volume, low-complexity groupings of cases. Such high-volume, low-complexity cases would serve as the topics for curriculum development for paramedic training in field treatment and referral. Methods. Data were obtained from ambulance run sheets and emergency department (ED) records for all patients transported by the HCMC ambulance service in 1996 who were covered by the Metropolitan Health Plan (MHP) and who were categorized for billing purposes as “ALS minor” transports. The data included demographic information, vital signs, presenting problem, diagnoses in the ED, and procedures, laboratory studies, or x-rays done in the ED. Patients were classified as “potentially treatable” in the field if they were treated and discharged from the ED without undergoing any procedures or diagnostic studies. Patients who required more extensive evaluation in the ED, or who were admitted, were classified as likely too “complex” to be treated at the scene and then referred for early follow-up. The data were analyzed to find the most common presenting problems and the numbers, characteristics, and dispositions of “potentially treatable” and “complex” patients in each group. This information was used to determine what, if any, types of patients could potentially be treated safely and effectively according to this scheme. Results. The study group comprised 1,103 patients, representing 127 different presenting medical problems. There were 523 (47%) “potentially treatable” patients and 580 (53%) “complex” patients. The 127 medical problems were grouped and the 15 most common presenting problem groups were identified. Within these groups there was no single medical problem with high volume. Each of these 15 most common problem groups contained a substantial proportion of “complex” patients, ranging from 24% to 100%. Conclusions. None of the 15 most frequently encountered problem groups consisted of a high enough proportion of “potentially treatable” cases to serve as a high-volume, low-complexity category for paramedic treatment in the field with early follow-up. Without any identified high-volume, low-complexity categories, a treatment and referral program as proposed in this article would require a substantial investment in development of appropriate criteria and in training paramedics to apply the criteria for numerous clinical entities. This would limit any cost saving, and require great care to avoid compromising patient safety accompanied by substantial professional liability exposure.

Prehospital sedation with intramuscular droperidol: A one-year pilot

Objective. Combative patients pose a threat to themselves and prehospital personnel, and are at risk for sudden death. Droperidol is an antipsychotic and sedative agent that might be effectively utilized by paramedics to assist in the management of uncontrollably violent patients. Methods. A prospective observational study of patients requiring sedation was conducted in an urban third-service emergency medical services system (55,000 calls per year). Patients were scored by paramedics on a five-point agitation scale with 5 being extremely combative (continuous, vigorous fighting against restraints) and 1 being somnolent (sleeping or sleepy). Eligible (score 4–5) patients received 5 mg of intramuscular droperidol on direct physician order. Data including vital signs and agitation scores were recorded at 5-minute intervals until hospital arrival. Adverse effects were also recorded. Results. Fifty-three patients received droperidol (51 patients received 5 mg; two received 2.5 mg) during the study period. The average predrug agitation score was 4.7 (±0.1 SD). The average 5-minute postdrug score was 3.9 (±0.1 SD, 95% CI 3.7–4.1). The average 10-minute postdrug score was 3.3 (±0.1 SD, 95% CI 3.1–3.6). The average hospital arrival score was 2.8 (±0.1 SD, 95% CI 2.5–3.1). One patient became obtunded and required supplemental oxygen; no other patient experienced an adverse event after receiving droperidol. Sedation was ineffective in seven patients, three of whom had head injuries, and one of whom received 2.5 mg of droperidol per physician order. Paramedics sustained no needlestick exposures. Conclusion. Intramuscular droperidol contributed to effective and rapid prehospital sedation in this observational series of 53 combative patients.

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.

Very Rapid Treatment of ST-Segment―Elevation Myocardial Infarction: Utilizing Prehospital Electrocardiograms to Bypass the Emergency Department

Prehospital ECG (PH-ECG) has been identified as a strategy to help reduce door-to-balloon (D2B) time during emergency treatment with percutaneous coronary intervention (PCI) for patients with ST-elevation myocardial infarction (STEMI).1 National Registry of Myocardial Infarction data from 2000–2002 suggest utilization rates of PH-ECG of 7000 patients with acute coronary syndrome transported by emergency medical services (EMS) during 2007 found PH-ECG utilization rates of 27.4%.3 Among this cohort, D2B times were significantly shorter than the cohort of patients without PH-ECG, and there was a trend toward lower in-hospital mortality. Systems of care that have incorporated PH-ECGs into a citywide or region-wide strategy have demonstrated a significant reduction in D2B times, usually by triaging patients in the prehospital setting, bypassing non-PCI-capable hospitals, and transporting patients directly to a designated STEMI receiving center (SRC) capable of providing primary PCI.4,5 Rapid and accurate interpretation of the PH-ECG is a critical step in the process of incorporating PH-ECG into systems of care for acute STEMI. Different models for interpretation of PH-ECGs have been described, including computer algorithm interpretation, wireless transmission to designated centers for physician interpretation, and direct paramedic interpretation.1 Previous studies demonstrated that trained EMS personnel can reliably identify STEMI on the PH-ECG.6,7 We initiated a program to evaluate a novel strategy to reduce D2B time for patients with STEMI who undergo PCI. The intent was to expedite prehospital triage and to reduce emergency department (ED) delays to treatment with PCI for patients with acute STEMI. We empowered EMS personnel to interpret the PH-ECG in the prehospital setting and then to activate the cardiac catheterization laboratory (CV laboratory) staff before transporting the patient to …