Frequency of intraoperative cardiac arrest and medium-term survival

Abstract

CONTEXT AND OBJECTIVE: Although advances in surgical and anesthetic techniques have reduced perioperative morbidity-mortality, the survival rate following cardiac arrest remains low. The aim of this study was to evaluate, over the course of one year, the prevalence of intraoperative cardiac arrest and the 30-day survival rate after this event in a tertiary teaching hospital. DESIGN AND SETTING: Prospective cohort study in a tertiary teaching hospital. METHODS: Following approval by the institutional ethics committee, anesthetic procedures and cases of intraoperative cardiac arrest between January and December 2007 were evaluated. Patients undergoing cardiac surgery were excluded. The data were gathered prospectively using the modified Utstein model, with evaluation of demographic data, pre-arrest conditions, intraoperative care, care during arrest and postoperative outcome up to the 30 th day. The data were recorded by the attending anesthesiologist. RESULTS: During the study period, 40,379 anesthetic procedures were performed, and 52 cases of intraoperative cardiac arrest occurred (frequency of 13:10,000). Among these, 69% presented spontaneous return of circulation after the initial arrest, and only 25% survived for 30 days after the event. The following factors were associated with shorter survival: American Society of Anesthesiologists physical status IV and V, emergency surgery, hemorrhagic events, hypovolemia as the cause of arrest and use of atropine during resuscitation. CONCLUSIONS: Although the frequency of cardiac arrest in the surgical environment has declined and resources to attend to this exist, the survival rate is low. Factors associated with worst prognosis are more frequent in critical patients. RESUMOCONTEXTO E OBJETIVO: Apesar de avanços nas técnicas cirúrgicas e anestésicas terem reduzido a morbimortalidade perioperatória, a taxa de sobrevivência após parada cardíaca (PC) permanece baixa. O objetivo deste estudo foi avaliar, ao longo de um ano, a incidência de PC intraoperatória e de sobrevida por 30 dias após esse evento em um hospital terciário de ensino.

Perioperative cardiac arrest: an evolutionary analysis of the intra-operative cardiac arrest incidence in tertiary centers in Brazil

“…Anesthesia, after the year 1984, greatly decreased its importance as the cause of ICA, being less important that surgical causes and ASA status. 7,18,21,22 The incidence of the event during all of the analyzed periods was higher during general anesthesia than with subdural, epidural, sacral or regional anesthesia.…”

“…In 2007, a great decrease in the incidence of ICA and lethality was noticed, having an incidence of 13 ICA per 10,000 anesthetics, with an immediate lethality of 30.8%. 21 Although the two studies performed by Braz et al included cardiac surgery and PACU arrests, the study done by Sebbag et al did not. Cardiac surgery ICA and PACU arrests were responsible, respectively, for 14.8% and 5.4% of the total arrests during the years 1996---2005; 3.85% and 6.52% in the years 1988---1996.…”

“…The fourth study was performed by Sebbag et al, during the year 2007, which included 40,437 patients. 21 Together, these studies analyzed the incidence of 204,072 patients undergoing regional or general anesthesia in two tertiary and academic hospitals, which resulted in 627 cases of ICA. The mean ICA incidence for the 25 years period was 30.72:10,000 anesthesias ( Table 2).…”

“…Cardiac surgery ICA and PACU arrests were responsible, respectively, for 14.8% and 5.4% of the total arrests during the years 1996---2005; 3.85% and 6.52% in the years 1988---1996. 18,21,22 Recalculating the incidence of ICA, excluding cardiac surgery and PACU arrests, there was an incidence of 21.9:10,000 anesthetics for the years 1988---1996, 28.1:10,000 anesthetics for the years 1996---2005, and 13:10,000 in 2007, again showing a reduction of ICA in the last years. 7,18,21,22 During the first years of the analyzed period (1982---1984), 76.7% of ICA that occurred during elective surgeries was related to anesthesia and the comorbidities were responsible for only 5.9%.…”

“…During the year 2007, the most common cause of the studied adverse events was hypovolemia (42%), followed by respiratory (21%) and metabolic (21%) disturbances and the ICA mainly occurred during the maintenance period of general or combined anesthesia. 18,21,22 When analyzing the lethality of the CA (calculated dividing the number of deaths by the total CAs), in the years 1982---1984, it was 12% for anesthesia, 76.3% for surgery and 46.4% for comorbidities. In the study of Braz et al during the period of 1988---1996, the anesthetic lethality of ICA was 24% with an overall lethality of 67.3%.…”