Part 6: Advanced Cardiovascular Life Support

The International Liaison Committee on Resuscitation-Review of the last 25 years and vision for the future

2017 marks the 25th anniversary of the International Liaison Committee on Resuscitation (ILCOR). ILCOR was formed in 1992 to create a forum for collaboration among principal resuscitation councils worldwide. Since then, ILCOR has established and distinguished itself for its pioneering vision and leadership in resuscitation science. By systematically assessing the evidence for resuscitation standards and guidelines and by identifying national and regional differences, ILCOR reached consensus on international resuscitation guidelines in 2000, and on international science and treatment recommendations in 2005, 2010 and 2015. However, local variation and contextualization of guidelines are evident by subtle differences in regional and national resuscitation guidelines. ILCOR's efforts to date have enhanced international cooperation, and progressively more transparent and systematic collection and analysis of pertinent scientific evidence. Going forward, this sets the stage for ILCOR to pursue its vision to save more lives globally through resuscitation.

Should advanced age be a limiting factor in providing therapeutic hypothermia to cardiac arrest survivors? A single-center observational study

As octogenarians represent the fastest growing segment of the elderly population and the incidence of out-of-hospital cardiac arrest (OHCA) increases with age, the outcome benefit of therapeutic hypothermia (TH) in comatose cardiac arrest survivors is of great interest. The first randomized controlled trials of TH excluded all patients older than 75 years and there exists considerable uncertainty whether the positive findings from these studies apply to older patients. This is a retrospective study of all unconscious OHCA survivors from 2002 to 2008 treated with TH in our intensive care unit who fulfilled the Hypothermia After Cardiac Arrest study inclusion criteria (witnessed, shockable OHCA receiving bystander-cardiopulmonary resuscitation (CPR), interval from collapse to ambulance arrival <15 minutes, and return of spontaneous circulation [ROSC] within 60 minutes) but with no upper age limit. Good cerebral outcome was defined as a Glasgow-Pittsburgh Cerebral Performance Category 1-2. The median age of the 113 OHCA survivors studied was 62 years (18-89 years), and 77% were men. Median time from collapse to ROSC was 15 minutes (3-50 minutes). Bystander CPR was performed in 76% and immediate postresuscitation coronary angiography in 63%. The overall good outcome rate was 70%. Both lower age and shorter time to ROSC, as well as bystander CPR and the time period after implementation of the ERC 2005 guidelines were associated with good outcome. Still, 54% of all patients aged >75 years achieved good outcome. Although age seems to influence outcome, we found that more than half of comatose OHCA survivors above 75 years showed a favorable outcome. Hence, our data do not support a limitation of postresuscitation TH based on age alone but highlights the need for more clinical trials of TH in the advanced age group.

Adherence to resuscitation guidelines during prehospital care of cardiac arrest patients

OBJECTIVE

The impact of prehospital care after the return of spontaneous circulation in out-of-hospital cardiac arrest patients is not known. This study describes adherence to the resuscitation guidelines, factors associated with poor adherence and possible impact of prehospital postresuscitation care on the outcome of out-of-hospital cardiac arrest.

METHODS

One hundred and fifty-seven Finnish out-of-hospital cardiac arrest patients hospitalized during 1 year, were analyzed retrospectively. Patient and arrest characteristics, prehospital postresuscitation care and survival to hospital discharge were analyzed using multivariate logistic regression.

RESULTS

Forty percent of the patients received care accordant with the guidelines. Male sex (P=0.045), witnessed arrest (P=0.031), initial ventricular fibrillation/ventricular tachycardia rhythm (P=0.007) and the presence of an emergency physician (P=0.017) were associated with care in line with the current guidelines. In multivariate logistic regression analysis, age over median (odds ratio=3.6, 95% confidence interval 1.5-8.6), nonventricular fibrillation/ventricular tachycardia initial rhythm (odds ratio=4.0, 95% confidence interval 1.6-9.8), administration of adrenaline (odds ratio=7.0, 95% confidence interval 2.3-21.4) and unsatisfactory prehospital postresuscitation care (odds ratio=2.5, 95% confidence interval 1.1-6.3) were associated with a failure to survive up to hospital discharge.

CONCLUSIONS

Less than 50% of out-of-hospital cardiac arrest patients received prehospital postresuscitation care compatible with the current guidelines. Markers of poor prognosis were associated with unsatisfactory care, which in turn was more frequent among the patients who did not survive to hospital discharge. The importance of the guidelines should be highlighted in the future.

Rapid implementation of therapeutic hypothermia in comatose out-of-hospital cardiac arrest survivors

BACKGROUND

The implementation of therapeutic hypothermia (TH) into daily clinical practice appears to be slow. We present our experiences with rapid implementation of a simple protocol for TH in comatose out-of-hospital cardiac arrest (OHCA) survivors.

METHODS

From June 2002, we started cooling pre-hospitally with sport ice packs in the groin and over the neck. In the intensive care unit (ICU), we used ice-water soaked towels over the torso. All patients were endotracheally intubated, on mechanical ventilation and sedated and paralysed. The target temperature was 33 +/- 1 degrees C to be maintained for 12-24 h. We used simple inclusion criteria: (i) no response to verbal command during the ambulance transport independent of initial rhythm and cause of CA; (ii) age 18-80 years; and (iii) absence of cardiogenic shock (SBP < 90 mmHg despite vasopressors). We compared the first 27 comatose survivors with a presumed cardiac origin of their OHCA with 34 historic controls treated just before implementation.

RESULTS

TH was initiated in all 27 eligible patients. The target temperature was reached in 24 patients (89% success rate). ICU- and hospital- length of stay did not differ significantly before and after implementation of TH. Hypokalemia (P= 0.001) and insulin resistance (P= 0.025) were more common and seizures (P= 0.01) less frequently reported with the use of TH. The implementation of TH was associated with a higher hospital survival rate (16/27; 59% vs. 11/34; 32%, respectively; P< or = 0.05). Our results indicate a population-based need of approximately seven cooling patients per 100,000 person-years served.

CONCLUSION

Our simple, external cooling protocol can be implemented overnight in any system already treating post-resuscitation patients. It was well accepted, feasible and safe, but not optimal in terms of cooling rate. Neither safety concerns nor costs should be a barrier for implementation of TH.

A prospective, randomised and blinded comparison of first shock success of monophasic and biphasic waveforms in out-of-hospital cardiac arrest

BACKGROUND

Evidence suggests that biphasic waveforms are more effective than monophasic waveforms for defibrillation in out-of-hospital cardiac arrest (OHCA), yet their performance has only been compared in un-blinded studies.

METHODS AND RESULTS

We compared the success of biphasic truncated exponential (BTE) and monophasic damped sine (MDS) shocks for defibrillation in OHCA in a prospective, randomised, double blind clinical trial. First responders were equipped with MDS and BTE automated external defibrillators (AEDs) in a random fashion. Patients in ventricular fibrillation (VF) received BTE or MDS first shocks of 200 J. The ECG was recorded for subsequent analysis continuously. The success of the first shock as a primary endpoint was removal of VF and required a return of an organized rhythm for at least two QRS complexes, with an interval of <5 s, within 1 min after the first shock. The secondary endpoint was termination of VF at 5 s. VF was the initial recorded rhythm in 120 patients in OHCA, 51 patients received BTE and 69 received MDS shocks. The success rate of 200 J first shocks was significantly higher for BTE than for MDS shocks, 35/51 (69%) and 31/69 (45%), P=0.01. In a logistic regression model the odds ratio of success for a BTE shock was 4.01 (95% CI 1.01-10.0), adjusted for baseline cardiopulmonary resuscitation, VF-amplitude and time between collapse and first shock. No difference was found with respect to the secondary endpoint, termination of VF at 5 s (RR 1.07 95% CI: 0.99-1.11) and with respect to survival to hospital discharge (RR 0.73 95% CI: 0.31-1.70).

CONCLUSION

BTE-waveform AEDs provide significantly higher rates of successful defibrillation with return of an organized rhythm in OHCA than MDS waveform AEDs.

In-hospital factors associated with improved outcome after out-of-hospital cardiac arrest. A comparison between four regions in Norway

INTRODUCTION

While pre-hospital factors related to outcome after out-of-hospital cardiac arrest (OHCA) are well known, little is known about possible in-hospitals factors related to outcome.

HYPOTHESIS

Some in-hospital factors are associated with outcome in terms of survival.

MATERIAL AND METHODS

An historical cohort observational study of all patients admitted to hospital with a spontaneous circulation after OHCA due to a cardiac cause in four different regions in Norway 1995-1999: Oslo, Akershus, Østfold and Stavanger.

RESULTS

In Oslo, Akershus, Østfold and Stavanger 98, 84, 91 and 186 patients were included, respectively. Hospital mortality was higher in Oslo (66%) and Akershus (64%) than in Østfold (56%) and Stavanger (44%), P=0.002. By multivariate analysis the following pre-arrest and pre-hospital factors were associated with in-hospital survival: age <or=71 years, better pre-arrest overall performance, a call-receipt-start CPR interval <or=1 min, and no use of adrenaline (epinephrine). The in-hospital factors associated with survival were: no seizures, base excess >-3.5 mmol l(-1), body temperature <or=37.8 degrees C, and serum glucose <or=10.6 mmol l(-1) 1-24 h after admittance with OR (95% CI) 2.72 (1.09-8.82, P=0.033), 1.12 (1.02-1.23, P=0.016), 2.67 (1.17-6.20, P=0.019) and 2.50 (1.11-5.65, P=0.028), respectively. Pre-arrest overall function, whether adrenaline was used, body temperature, the occurrence of hypotensive episodes, and the degree of metabolic acidosis differed between the four regions in parallel with the in-hospital survival rates.

CONCLUSION

Both pre-arrest, pre- and in-hospital factors were associated with in-hospital survival after OCHA. It seems important also to report in-hospital factors in outcome studies of OCHA. The design of the study precludes a conclusion on causability.

Feasibility of external cranial cooling during out-of-hospital cardiac arrest

Hypothermia during brain ischemia can improve neurological outcome. This study tested whether local cranial cooling during the low-flow state of cardiopulmonary resuscitation (CPR) could produce clinically significant cerebral cooling. Ice was applied to the heads and necks of subjects (hypothermia group) with out-of-hospital cardiac arrest (OOHCA) during CPR. Nasopharyngeal and tympanic temperatures were measured as surrogates for cerebral temperature. The rate of cranial cooling in the hypothermia group (-0.06 +/- 0.06 degrees C/min) was not significantly increased compared with a control group without ice (-0.04 +/- 0.07 degrees C/min), although older age was associated with more rapid cranial cooling. Of note, many subjects with OOHCA are already mildly hypothermic (mean cranial temperature= 35.0 +/- 1.2 degrees C) when they are first encountered in the field. This study suggests that brief cranial cooling is ineffective for rapidly lowering brain temperature. However, most cardiac arrest victims are spontaneously mildly hypothermic and preventing rewarming may provide some of the desired benefits of cerebral hypothermia.

Use of the esophageal tracheal combitube by basic emergency medical technicians

The most appropriate airway device for use in EMS systems staffed by basic skilled EMTs with (EMT-Ds) or without (EMT-Bs) defibrillation capabilities is still a matter of debate. The purpose of this study was to assess the feasibility, safety and effectiveness of the Esophageal Tracheal Combitube (ETC) when used by EMT-Ds in cardiorespiratory arrest patients of all etiologies. The EMTs had automatic external defibrillator (AED) training but no prior advanced airway technique skills. The prehospital intervention was reviewed using the EMTs cardiac arrest report, the AED tape recording of the event and the assessment of the receiving emergency physician. The patients' hospital records and autopsy report were reviewed in search of complications. Eight hundred and thirty-one adult cardiac arrest patients were studied. Placement was successful in 725 (95.4%) of the 760 patients where it was attempted and ventilation was successful in 695 (91.4%). Immediate complications encountered, but not necessarily related to the use of the ETC, were; subcutaneous emphysema (18), tension pneumothorax (5), blood in the oropharynx (15), and swelling of the pharynx (three). An autopsy was done in 133 patients; no esophageal lesions or significant injury to the airway structures were observed. Our results suggest that EMT-Ds can use the ETC for control of the airway and ventilation in cardiorespiratory arrest patients safely and effectively.

Field management of avalanche victims

The median annual mortality from snow avalanches registered in Europe and North America 1981-1998 was 146 (range 82-226); trend stable in Alpine countries (r=-0.29; P=0.24), increasing in North America (r=0.68; P=0.002). Swiss data over the same period document 1886 avalanche victims, with an overall mortality rate of 52.4% in completely-buried, versus 4.2% in partially-, or non-buried, persons. Survival probability in completely-buried victims in open areas (n=638) plummets from 91% 18 min after burial to 34% at 35 min, then remains fairly constant until a second drop after 90 min. Likewise, survival probability for completely-buried victims in buildings or on roads (n=97) decreases rapidly following burial initially, but as from 35 min it is significantly higher than that for victims in open areas, with a maximum difference in respective survival probability (31% versus 7%) from 130 to 190 min (P<0.001). Standardised guidelines are introduced for the field management of avalanche victims. Strategy by rescuers confronted with the triad hypoxia, hypercapnia and hypothermia is primarily governed by the length of snow burial and victim's core temperature, in the absence of obviously fatal injuries. With a burial time < or =35 min survival depends on preventing asphyxia by rapid extrication and immediate airway management; cardiopulmonary resuscitation for unconscious victims without spontaneous respiration. With a burial time >35 min combating hypothermia becomes of paramount importance. Thus, gentle extrication, ECG and core temperature monitoring and body insulation are mandatory; unresponsive victims should be intubated and pulseless victims with core temperature <32 degrees C (89.6 degrees F) (prerequisites being an air pocket and free airways) transported with continuous cardiopulmonary resuscitation to a specialist hospital for extracorporeal re-warming.

European Resuscitation Council Guidelines 2000 for Adult Advanced Life Support. A statement from the Advanced Life Support Working Group(1) and approved by the Executive Committee of the European Resuscitation Council

The European Resuscitation Council (ERC) last issued guidelines for Basic Life Support (BLS) in 1998 [1]. These were based on the 1997 International Liaison Committee on Resuscitation (ILCOR) Advisory Statements [2]. In 1999 and 2000 representatives of ILCOR, at the invitation of the American Heart Association, met on a number of occasions in Dallas to agree a Consensus on Science upon which future guidelines would be based. Representatives from the ERC played a prominent role in the deliberations, which culminated in the publication of "Guidelines 2000 for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care--A Consensus on Science" in August 2000 [3]. The consensus was evidence-based wherever possible. The ERC ALS Working Group has considered this document and has recommended some changes in the guidelines that will be suitable for European practice. These changes, together with a summary of the Sequence of Actions in ALS, are presented in this paper.