The Presence of Agonal Respiration During Cardiac Arrest And

original papers

Adv Clin Exp Med 2011, 20, 6, 761–765 © Copyright by Wroclaw Medical University ISSN 1230-025X

Igor Chęciński1, Dorota Zyśko1, Jacek Smereka1, Jacek Gajek2, Janina Mirecka-Świerzko3, Ryszard Ściborski3, Marek Brodzki1, Paweł Wróblewski1, Andrzej Czyrek4, Anil K. Agrawal5 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, 2005. 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 2.4–63.4 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, 761–765). 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 73 000 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- 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 2.4–63.4 (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, 761–765). Słowa kluczowe: oddychanie agonalne, zatrzymanie krążenia, CRP.

Agonal respiration could be defined as a terminal respiration and the influence of its presence on nal pattern occurring due to anoxia or brain isch- clinical outcome assessed as hospital admission emia [1] and is often seen in patients (up to 55% or survival. probably higher) in the early phase of cardiac arrest [2–5]. Agonal respiration is more frequent in ventricular fibrillation compared to other cardiac Material and Methods arrest rhythms [5]. It is often described as barely or occasionally breathing, occasional gasps, problem A retrospective analysis of medical records or irregular breathing, heavy or labored breath- from one Emergency Medical System call center ing, sighing, noisy breathing, gurgling, moaning, responsible for one district (an area which in ad- groaning or snorting [6]. Agonal breathing should ministration terms is a second level of the local not be mistaken for normal breathing and as a sign government in Poland) with a resident population of life which could result in withholding or a delay of 73,000. In the analyzed region, the EMS dis- in cardiopulmonary resuscitation attempts [2–4]. patchers were instructed to encourage and support Laypersons often inform dispatchers that victims witnesses in performing CPR in cases of suspected are breathing although they are in cardiac arrest cardiac arrest. The authors analyzed all medical and present agonal gasps [2]. In mammals, respira- records of the Emergency Medical Service from tory rhythm generation depends on the respiratory January 1st, 2004 to December 31st, 2005. Patients network, located in the preBötzinger complex in in cardiac arrest at presentation were identified the brainstem which consists of two types of pace- and only victims in whom resuscitation efforts maker neurons. Their bursting properties rely on were started were included for further analysis. the riluzole-sensitive persistent sodium current in The patient’s age, sex, arrival time, bystander CPR, the first type and in the second type they are sen- abnormal respiration as assessed by bystanders sitive to Cd2+ and flufenamic acid, a calcium-de- and the physician after EMS arrival, ECG rhythm, pendent nonspecific cationic current blocker [7]. and survival to hospital admission were analyzed. Normoxia and hypoxia exert disparate effects on Cardiac arrest was recognized by the EMS physi- their activity and the pattern of respiration [8]. cian according to European Resuscitation Council Agonal breathing is associated with important Guidelines for Resuscitation 2005 [10]. cardiorespiratory changes: improved pulmonary gas exchange, increased venous return to the heart, increased cardiac output, cardiac contractility, aor- Statistical Analysis tic pressure, and coronary perfusion pressure has The data was presented as a mean and respec- an auto-resuscitative meaning in immature mam- tive standard deviations for continuous variables mals and improves the outcome of cardiopulmo- and a number or percentages for categorical vari- nary resuscitation in mature mammals [1, 9]. The ables. The differences between variables were as- presence of agonal breathing suggests better brain sessed with a T-test, Mann-Whitney U-test or stem oxygenation i.e. shorter duration of the cardi- χ2 test as appropriate. ac arrest or its other primary mechanisms support- Logistic regression analysis was performed to ing the circulation even minimally. On the other assess the association between survival to hospi- hand it may simulate vital signs and thus delay re- tal admission and relevant clinical and CPR data suscitation attempts. The ability of laypersons to such as age, gender, VF/PVT at presentation, the recognize cardiac arrest when agonal respiration is presence of agonal respiration, time to EMS arrival present is believed to be low [5]. dichotomized according to its median value, by- The aim of the study was to assess bystander stander CPR, witnessed cardiac arrest and cardiac cardio-pulmonary resuscitation (CPR) frequency arrest at home. The associations of the presence in patients in cardiac arrest with and without ago- of agonal respiration at the time of medical staff Agonal Respiration Predictive Value 763 arrival and relevant CPR data and agonal respira- 8 of them (40%) had agonal respiration assessed by tion presence during the emergency call were also the bystander. Bystander CPR was not performed studied. in 46 patients and 15 of them had agonal respira- A P value less than 0.05 was considered sig- tion (33%). There was no association between the nificant. presence of agonal respiration and bystander CPR performance (p = ns). A stepwise logistic analysis revealed that the Results only factor related to bystander CPR performance was the longer time from the emergency call to The authors identified 66 patients aged emergency medical service staff arrival on the 64.5 ± 13 years who were eligible for inclusion in scene. Longer arrival times resulted in an increase the study. The demographics and out-of-hospital in bystander CPR resuscitation (OR 3.01 CI 1.02– characteristics are presented in Table 1. The me- 9.4 p < 0.05). dian of the time to the arrival was 6 minutes. Emergency medical service staff reported ago- Bystander CPR was performed on 20 patients, nal 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 Bystander resuscitation p Survived to hospital p (Liczba attempts admission pacjentów) (Podjęcie resuscytacji (Przeżycie do czasu przy- przez przygodnych bycia do szpitala) świadków zdarzenia) n = 66 YES n = 20 NO n = 46 YES n = 29 NO n = 37 Age: mean ± SD 64.5 ± 13.0 61.4 ± 11.9 65.9 ± 11.9 NS 65.5 ± 13.2 63.8 ± 12.9 (Wiek: średnia ± SD) Male gender – % 70 80 65 NS 69 70 NS (Płeć męska – %) Witnessed cardiac arrest – % 82 90 78 NS 93 73 NS (Zatrzymanie krążenia przy świad- kach – %) Cardiac arrest at home – % 70 40 82 < 0.01 72 68 NS (Zatrzymanie krążenia w domu – %) Bystander resuscitation attempts – % 30 100 0 41 22 NS (Podjęcie resuscytacji przez świad- ków zdarzenia – %) Agonal respiration assessed by wit- 35 40 33 NS 62 14 < 0.05 nesses – % (Oddychanie agonalne w ocenie świadków zdarzenia – %) Agonal respiration assessed by EMS 21 40 13 < 0.05 41 5 < 0.05 medical staff – % (Oddychanie agonalne w ocenie zes połu ratownictwa medycznego – %) VF/PVT at presentation – % 48 70 39 < 0.05 62 38 NS (VF/PVT w pierwszym badaniu EKG – %) Alive to hospital admission – % 44 63 40 < 0.05 100 0 (Przeżycie do przyjęcia do szpitala – %) Time to EMS arrival – min 7.1 ± 4.4 5.5 ± 4.9 7.8 ± 4.0 < 0.05 6.1 ± 3.4 7.9 ± 4.9 NS (Czas do przybycia zespołu ratownictwa medycznego – min) VF – ventricular fibrillation, PVT – pulseless ventricular tachycardia. VF – migotanie komór, PVT – częstoskurcz komorowy bez tętna. 764 I. Chęciński et al.

CPR instituted and 6 not resuscitated by layper- the quality of dispatcher instructions and the phys- sons). Agonal breathing during the emergency call ical and psychological ability of the layperson to and bystander CPR were related to agonal respira- perform CPR. The frequency of agonal breathing tion presence at the time of medical staff arrival upon emergency medical staff arrival was higher in (p < 0.05). patients who received bystander CPR. A stepwise logistic regression analysis revealed The role of cerebral blood flow maintenance that survival to hospital admission is related to ago- in supporting agonal respiration confirms the ob- nal respiration at the time of emergency medical ser- servation of the duration of agonal respiration in vice staff arrival (OR-12.4 CI 2.4–63.4 p < 0.001). patients in whom, on their own request, ventilator support was removed. The cessation of mechanical ventilation in these patients with preserved cardiac Discussion function and untreatable progressive neurological conditions could lead to long-lasting (up to 40 mi- Agonal respiration is a frequent finding during nutes) agonal respiration prior to terminal apnea cardiac arrest and its presence decreases with re- [14]. lapsing time. In this study, the frequency of agonal Present study confirms the importance of respiration reported by laypeople and recorded by resuscitation attempts provided by witnesses in dispatchers was 35%. This frequency is similar to order to prolong the period of agonal breathing, that reported by others authors. Clark et al. and which in turn may lead to minimal respiratory and Bang et al. reported 40% and Vaillancourt et al. circulatory function. Correctly provided resus- 37% incidence of agonal breathing during out-of- citation prolongs the period of agonal breathing. -hospital cardiac arrest [6, 11, 12]. A slightly lower The authors have found that patients with agonal incidence in present study may be the consequence respiration at presentation had better short-term of the study’s retrospective design, which could fa- survival rates than patients without agonal respira- vor underestimation of assessed events. tion, which is concordant with the results of other Agonal respiration may lead to the abandoning studies. of resuscitation attempts by a bystander because of The presence of agonal respiration may in- the conviction of life signs presence. This problem dicate higher than critical oxygen delivery to the should be overcome by cardiac arrest recogni- brainstem and confirms the good quality of CPR tion by the dispatcher and bystander instruction when it is maintained, but on the other hand it to perform CPR [4]. Perkins et al. demonstrated may be confusing for the rescuer when attempts to improved diagnostic accuracy and sensitivity of restore spontaneous circulation are ineffective but cardiac arrest recognition by giving instruction in agonal respiration persists. In such circumstances, recognizing agonal breathing [13]. the decision to stop further resuscitation attempts In present study there was no difference be- is especially difficult. tween the CPR frequency performed by bystand- The authors concluded that presence of agonal ers in patients with and without agonal respiration. respiration during cardiac arrest is not related to This finding indicates that other factors than ago- rarer resuscitation attempts by witnesses. Agonal nal respiration played a role in undertaking resus- respiration and CPR attempts by laypersons may citation attempts. The possible factors would be: improve short-term clinical outcome.

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Address for correspondence: Dorota Zyśko Teaching Department for the Emergency Medical Service Wroclaw Medical University Bartla 5 51-618 Wrocław Poland Tel.: +48 600 125 283

Conflict of interest: None declared

Received: 7.03.2011 Revised: 21.09.2011 Accepted: 7.12.2011