1 original papers Adv Clin Exp Med 2011, 20, 6, ISSN X Copyright by Wroclaw Medical University Igor Chęciński 1, Dorota Zyśko 1, Jacek Smereka 1, Jacek Gajek 2, Janina Mirecka-Świerzko 3, Ryszard Ściborski 3, Marek Brodzki 1, Paweł Wróblewski 1, Andrzej Czyrek 4, Anil K. Agrawal 5 The Presence of Agonal Respiration During Cardiac Arrest and Resuscitation Attempts by Witnesses Obecność oddychania agonalnego a podejmowanie prób resuscytacji przez przygodnych świadków zdarzenia 1 Teaching Department for the Emergency Medical Service, Wroclaw Medical University, Poland 2 Department of Cardiology, Wroclaw Medical University, Wroclaw, Poland 3 County Sanitary-Epidemiological Station, Olesnica, Poland 4 County Hospital, Olawa, Poland 5 2nd Department of General and Oncological Surgery, Wroclaw Medical University, Poland Abstract Background. Agonal respiration could be defined as a terminal pattern occurring due to anoxia or brain ischemia and is often seen in patients in the early phase of cardiac arrest. Objective. To assess bystander CPR (cardio-pulmonary resuscitation) frequency in patients in cardiac arrest with and without agonal respirations and the influence of this phenomenon on clinical outcome. Material and Methods. A retrospective study was conducted on EMS cardiac arrest medical records from one district in Poland with a resident population of 73,000 from January 1st, 2004 to December 31st, Results. Sixty-six patients aged 65.4 ± 13 years were eligible for inclusion in the study. Bystander CPR was performed on 20 patients, 8 of them had agonal respiration assessed by the bystander. Bystander CPR was not performed on 46 patients and 15 of them had agonal respiration. Emergency medical service staff reported agonal respiration on arrival in 14 cases and 8 of them had had resuscitation attempts provided by bystanders. A stepwise logistic regression analysis revealed that survival to hospital admission is related to agonal respiration at the time emergency medical service staff arrival (OR-12.4 CI p < 0.001). Conclusions. The presence of agonal respiration during cardiac arrest is not related to rarer resuscitation attempts by witnesses. Agonal respiration and CPR attempts by laypersons may improve short-term clinical outcome (Adv Clin Exp Med 2011, 20, 6, ). Key words: agonal respiration, cardiac arrest, CPR. Streszczenie Wprowadzenie. Oddychanie agonalne występuje wtedy, kiedy dochodzi do niedotlenienia lub niedokrwienia mózgu i często jest stwierdzane u pacjentów z zatrzymaniem krążenia. Cel pracy. Ocena, czy prowadzenie przez przygodnych świadków zdarzenia resuscytacji krążeniowo-oddechowej u pacjentów z zatrzymaniem krążenia wpływa na występowanie oddychania agonalnego oraz jakie to zjawisko ma znaczenie na krótkoterminowe przeżycie pacjentów. Materiał i metody. Badanie miało charakter retrospektywny i polegało na analizie dokumentacji medycznej dotyczącej przypadków zatrzymania krążenia na obszarze działania Pogotowia Ratunkowego Podstacji w Oławie, który zamieszkuje mieszkańców, od 1 stycznia 2004 r. do 31 grudnia 2005 r. Wyniki. Do badania zakwalifikowano 66 pacjentów w wieku 65,4 ± 13,0 lat. Resuscytacja przez przygodnych świadków zdarzenia była podjęta u 20 pacjentów, z których u 8 występowało oddychanie agonalne stwierdzone przez tych świadków. Przygodni świadkowie zdarzenia nie podjęli resuscytacji u 46 pacjentów, z których 15 miało agonalne oddychanie. Członkowie zespołów ratownictwa medycznego stwierdzili występowanie oddychania ago-
2 762 I. Chęciński et al. nalnego u 14 osób, wśród nich u 8 pacjentów przygodni świadkowie zdarzenia prowadzili czynności resuscytacyjne. Krokowa regresja logistyczna pozwoliła na wykazanie, że przeżycie do czasu przyjęcia do szpitala było związane ze stwierdzeniem oddychania agonalnego przez członków zespołów ratownictwa medycznego: OR-12.4 CI (p < 0.001). Wnioski. Obecność oddychania agonalnego nie jest czynnikiem, który wpływa na podjęcie lub zaniechanie czynności resuscytacyjnych przez przygodnych świadków zdarzenia. Oddychanie agonalne i podjęcie przez przygodnych świadków zdarzenia czynności resuscytacyjnych może poprawiać krótkoterminowe rokowanie (Adv Clin Exp Med 2011, 20, 6, ). Słowa kluczowe: oddychanie agonalne, zatrzymanie krążenia, CRP. Agonal respiration could be defined as a terminal pattern occurring due to anoxia or brain ischemia  and is often seen in patients (up to 55% or probably higher) in the early phase of cardiac arrest [2 5]. Agonal respiration is more frequent in ventricular fibrillation compared to other cardiac arrest rhythms . It is often described as barely or occasionally breathing, occasional gasps, problem or irregular breathing, heavy or labored breathing, sighing, noisy breathing, gurgling, moaning, groaning or snorting . Agonal breathing should not be mistaken for normal breathing and as a sign of life which could result in withholding or a delay in cardiopulmonary resuscitation attempts [2 4]. Laypersons often inform dispatchers that victims are breathing although they are in cardiac arrest and present agonal gasps . In mammals, respiratory rhythm generation depends on the respiratory network, located in the prebötzinger complex in the brainstem which consists of two types of pacemaker neurons. Their bursting properties rely on the riluzole-sensitive persistent sodium current in the first type and in the second type they are sensitive to Cd2+ and flufenamic acid, a calcium-dependent nonspecific cationic current blocker . Normoxia and hypoxia exert disparate effects on their activity and the pattern of respiration . Agonal breathing is associated with important cardiorespiratory changes: improved pulmonary gas exchange, increased venous return to the heart, increased cardiac output, cardiac contractility, aortic pressure, and coronary perfusion pressure has an auto-resuscitative meaning in immature mammals and improves the outcome of cardiopulmonary resuscitation in mature mammals [1, 9]. The presence of agonal breathing suggests better brain stem oxygenation i.e. shorter duration of the cardiac arrest or its other primary mechanisms supporting the circulation even minimally. On the other hand it may simulate vital signs and thus delay resuscitation attempts. The ability of laypersons to recognize cardiac arrest when agonal respiration is present is believed to be low . The aim of the study was to assess bystander cardio-pulmonary resuscitation (CPR) frequency in patients in cardiac arrest with and without agonal respiration and the influence of its presence on clinical outcome assessed as hospital admission survival. Material and Methods A retrospective analysis of medical records from one Emergency Medical System call center responsible for one district (an area which in administration terms is a second level of the local government in Poland) with a resident population of 73,000. In the analyzed region, the EMS dispatchers were instructed to encourage and support witnesses in performing CPR in cases of suspected cardiac arrest. The authors analyzed all medical records of the Emergency Medical Service from January 1st, 2004 to December 31st, Patients in cardiac arrest at presentation were identified and only victims in whom resuscitation efforts were started were included for further analysis. The patient s age, sex, arrival time, bystander CPR, abnormal respiration as assessed by bystanders and the physician after EMS arrival, ECG rhythm, and survival to hospital admission were analyzed. Cardiac arrest was recognized by the EMS physician according to European Resuscitation Council Guidelines for Resuscitation 2005 . Statistical Analysis The data was presented as a mean and respective standard deviations for continuous variables and a number or percentages for categorical variables. The differences between variables were assessed with a T-test, Mann-Whitney U-test or χ 2 test as appropriate. Logistic regression analysis was performed to assess the association between survival to hospital admission and relevant clinical and CPR data such as age, gender, VF/PVT at presentation, the presence of agonal respiration, time to EMS arrival dichotomized according to its median value, bystander CPR, witnessed cardiac arrest and cardiac arrest at home. The associations of the presence of agonal respiration at the time of medical staff
3 Agonal Respiration Predictive Value 763 arrival and relevant CPR data and agonal respiration presence during the emergency call were also studied. A P value less than 0.05 was considered significant. Results The authors identified 66 patients aged 64.5 ± 13 years who were eligible for inclusion in the study. The demographics and out-of-hospital characteristics are presented in Table 1. The median of the time to the arrival was 6 minutes. Bystander CPR was performed on 20 patients, 8 of them (40%) had agonal respiration assessed by the bystander. Bystander CPR was not performed in 46 patients and 15 of them had agonal respiration (33%). There was no association between the presence of agonal respiration and bystander CPR performance (p = ns). A stepwise logistic analysis revealed that the only factor related to bystander CPR performance was the longer time from the emergency call to emergency medical service staff arrival on the scene. Longer arrival times resulted in an increase in bystander CPR resuscitation (OR 3.01 CI p < 0.05). Emergency medical service staff reported agonal respiration on arrival in 14 cases (8 cases with Table 1. Patients and out-of-hospital cardiac arrest characteristics Tabela 1. Charakterystyka pacjentów i pozaszpitalnego zatrzymania krążenia Total (Liczba pacjentów) Bystander resuscitation attempts (Podjęcie resuscytacji przez przygodnych świadków zdarzenia) p Survived to hospital admission (Przeżycie do czasu przybycia do szpitala) p n = 66 YES n = 20 NO n = 46 YES n = 29 NO n = 37 Age: mean ± SD (Wiek: średnia ± SD) Male gender % (Płeć męska %) Witnessed cardiac arrest % (Zatrzymanie krążenia przy świadkach %) Cardiac arrest at home % (Zatrzymanie krążenia w domu %) Bystander resuscitation attempts % (Podjęcie resuscytacji przez świadków zdarzenia %) Agonal respiration assessed by witnesses % (Oddychanie agonalne w ocenie świadków zdarzenia %) Agonal respiration assessed by EMS medical staff % (Oddychanie agonalne w ocenie zespołu ratownictwa medycznego %) VF/PVT at presentation % (VF/PVT w pierwszym badaniu EKG %) Alive to hospital admission % (Przeżycie do przyjęcia do szpitala %) Time to EMS arrival min (Czas do przybycia zespołu ratownictwa medycznego min) 64.5 ± ± ± 11.9 NS 65.5 ± ± NS NS NS NS < NS NS NS < < < < NS < ± ± ± 4.0 < ± ± 4.9 NS VF ventricular fibrillation, PVT pulseless ventricular tachycardia. VF migotanie komór, PVT częstoskurcz komorowy bez tętna.
4 764 I. Chęciński et al. CPR instituted and 6 not resuscitated by laypersons). Agonal breathing during the emergency call and bystander CPR were related to agonal respiration presence at the time of medical staff arrival (p < 0.05). A stepwise logistic regression analysis revealed that survival to hospital admission is related to agonal respiration at the time of emergency medical service staff arrival (OR-12.4 CI p < 0.001). Discussion Agonal respiration is a frequent finding during cardiac arrest and its presence decreases with relapsing time. In this study, the frequency of agonal respiration reported by laypeople and recorded by dispatchers was 35%. This frequency is similar to that reported by others authors. Clark et al. and Bang et al. reported 40% and Vaillancourt et al. 37% incidence of agonal breathing during out-of- -hospital cardiac arrest [6, 11, 12]. A slightly lower incidence in present study may be the consequence of the study s retrospective design, which could favor underestimation of assessed events. Agonal respiration may lead to the abandoning of resuscitation attempts by a bystander because of the conviction of life signs presence. This problem should be overcome by cardiac arrest recognition by the dispatcher and bystander instruction to perform CPR . Perkins et al. demonstrated improved diagnostic accuracy and sensitivity of cardiac arrest recognition by giving instruction in recognizing agonal breathing . In present study there was no difference between the CPR frequency performed by bystanders in patients with and without agonal respiration. This finding indicates that other factors than agonal respiration played a role in undertaking resuscitation attempts. The possible factors would be: the quality of dispatcher instructions and the physical and psychological ability of the layperson to perform CPR. The frequency of agonal breathing upon emergency medical staff arrival was higher in patients who received bystander CPR. The role of cerebral blood flow maintenance in supporting agonal respiration confirms the observation of the duration of agonal respiration in patients in whom, on their own request, ventilator support was removed. The cessation of mechanical ventilation in these patients with preserved cardiac function and untreatable progressive neurological conditions could lead to long-lasting (up to 40 minutes) agonal respiration prior to terminal apnea . Present study confirms the importance of resuscitation attempts provided by witnesses in order to prolong the period of agonal breathing, which in turn may lead to minimal respiratory and circulatory function. Correctly provided resuscitation prolongs the period of agonal breathing. The authors have found that patients with agonal respiration at presentation had better short-term survival rates than patients without agonal respiration, which is concordant with the results of other studies. The presence of agonal respiration may indicate higher than critical oxygen delivery to the brainstem and confirms the good quality of CPR when it is maintained, but on the other hand it may be confusing for the rescuer when attempts to restore spontaneous circulation are ineffective but agonal respiration persists. In such circumstances, the decision to stop further resuscitation attempts is especially difficult. The authors concluded that presence of agonal respiration during cardiac arrest is not related to rarer resuscitation attempts by witnesses. Agonal respiration and CPR attempts by laypersons may improve short-term clinical outcome. References  Manole MD, Hickey RW: Preterminal gasping and effects on the cardiac function. Crit Care Med 2006, 34, S  Hauff SR, Rea TD, Culley LL, Kerry F, Becker L, Eisenberg MS: Factors impeding dispatcher-assisted telephone cardiopulmonary resuscitation. Ann Emerg Med 2003, 42,  Rea TD, Eisenberg MS, Culley LL, Becker L: Dispatcher-assisted cardiopulmonary resuscitation and survival in cardiac arrest. Circulation 2001, 104,  Bohm K, Rosenqvist M, Hollenberg J, Biber B, Engerström L, Svensson L: Dispatcher-assisted telephone-guided cardiopulmonary resuscitation: an underused lifesaving system. Eur J Emerg Med 2007, 14,  Eisenberg MS: Incidence and significance of gasping or agonal respirations in cardiac arrest patients. Curr Opin Crit Care 2006, 12,  Clark JJ, Larsen MP, Culley LL, Graves JR, Eisenberg MS: Incidence of agonal respirations in sudden cardiac arrest. Ann Emerg Med 1992, 21,  Peña F: Contribution of pacemaker neurons to respiratory rhythms generation in vitro. Adv Exp Med Biol 2008, 605,  Peña F, Parkis MA, Tryba AK, Ramirez JM: Differential contribution of pacemaker properties to the generation of respiratory rhythms during normoxia and hypoxia. Neuron 2004, 43,
5 Agonal Respiration Predictive Value 765  Ristagno G, Tang W, Sun S, Weil MH: Spontaneous gasping produces carotid blood flow during untreated cardiac arrest. Resuscitation 2007, 75,  Handley AJ, Koster K, Monsieurs K, Perkins GD, Davies S, Bossaert L: European Resuscitation Council Guidelines for Resuscitation 2005 Section 2. Adult basic life support and use of automated external defibrillators. Resuscitation 2005, 67S1, S7 S23.  Bång A, Herlitz J, Martinell S: Interaction between emergency medical dispatcher and caller in suspected out-of- -hospital cardiac arrest calls with focus on agonal breathing. A review of 100 tape recordings of true cardiac arrest cases. Resuscitation 2003, 56,  Vaillancourt C, Verma A, Trickett J, Crete D, Beaudoin T, Nesbitt L, Wells GA, Stiell IG: Evaluating the effectiveness of dispatch-assisted cardiopulmonary resuscitation instructions. Acad Emerg Med 2007, 14,  Perkins GD, Walker G, Christensen K, Hulme J, Monsieurs KG: Teaching recognition of agonal breathing improves accuracy of diagnosing cardiac arrest. Resuscitation 2006, 70,  Perkin RM, Resnik DB: The agony of agonal respiration: is the last gasp necessary? J Med Ethics 2002, 28, Address for correspondence: Dorota Zyśko Teaching Department for the Emergency Medical Service Wroclaw Medical University Bartla Wrocław Poland Tel.: Conflict of interest: None declared Received: Revised: Accepted: