Intraoperative cardiac arrests are rare but can cause severe complications or even death for the patient. According to Spruce et al., the incidence is between 0.8 to 4.3 per 10,000 cases [1]. The rate of anesthesia-related cardiac arrests is even lower, at around 0.6 per 10,000 anesthetics administered [2]. Despite the low incidence of these events, the importance of understanding how to prevent anesthesia-related cardiac arrest cannot be understated; therefore, it is imperative for anesthesia providers to be prepared in the event of unanticipated complications.
Causes of intraoperative anesthesia-related cardiac arrests vary from study to study. One study followed 104 patients who sustained cardiac arrest within 24 hours of operation and found that 11 cases were anesthesia-related. The majority of these cases were the result of respiratory and airway-related adverse events. In other cases, cardiovascular events such as myocardial infarction, local anesthetic toxicity, regional block, and over-sedation were the primary causes. It was also suggested that spinal anesthesia and neuraxial blockade mechanisms might be responsible in some cases, but the reasons remain unclear and require more investigation. However, a clear pattern can be identified as most patients who experienced anesthesia-related cardiac arrests were 85 years old and above, and two-thirds of patients in this group experienced cardiovascular collapse after neuraxial anesthesia. Many also had pre-existing conditions such as hypertension, coronary artery disease, and arrhythmia. This pattern emphasizes the need to conduct careful, detailed preoperative evaluations on high-risk patients. Adopting evidence-based safety protocols is the most basic step in avoiding anesthesia-related cardiac arrest in older patients [3].
A study conducted in a tertiary cancer center in China reported a significant decline in the incidence of cardiac arrests due to anesthesia-related factors from 2.1 per 10,000 anesthetics during the period between 1969 and 1978 to 0.05 per 10,000 anesthetics from 1989 to 2001. The researchers attributed this improvement to technological advancements in airway management and better monitoring of patients in the post anesthesia care unit [4]. An observation made in Ellis et al.’s study supports this conclusion – the majority of anesthesia-related cardiac arrests occurred during or after transport to the post anesthesia care unit [2]. Therefore, it is clear that postoperative care after a patient emerges from anesthesia is crucial to avoiding cardiac arrests. In regard to airway management, improvements in equipment over the years have made anesthesia increasingly safe, but non-technical aspects should not be overlooked, and providers should practice effective communication and sharp decision-making if an airway crisis should arise [5].
Anesthesia-related cardiac arrests are rare, but providers must be aware and able to identify patients who have a higher risk of experiencing one. Detailed preoperative evaluations must be conducted to identify any pre-existing conditions, and these patients should be closely monitored postoperatively as well. Awareness of safety protocols is the first step to preventing anesthesia-related cardiac arrests.
References
1. Sprung J, Warner ME, Contreras MG, et al. Predictors of survival following cardiac arrest in patients undergoing noncardiac surgery: a study of 518,294 patients at a tertiary referral center. Anesthesiology. 2003;99(2):259-269. https://doi.org/10.1097/00000542-200308000-00006
2. Ellis SJ, Newland MC, Simonson JA, Peters KR, Romberger DJ, Mercer DW, Tinker JH, Harter RL, Kindscher JD, Qiu F, Lisco SJ. Anesthesia-related Cardiac Arrest. Anesthesiology. 2014; 120:829–838 https://doi.org/10.1097/ALN.0000000000000153
3. Gong CL, Hu JP, Qiu ZL et al. A study of anaesthesia-related cardiac arrest from a Chinese tertiary hospital. BMC Anesthesiol. 18, 127 (2018). https://doi.org/10.1186/s12871-018-0593-6
4. Han F, Wang Y, Wang Y, Dong J, Nie C, Chen M, & Hou L. (2017). Intraoperative cardiac arrest: A 10-year study of patients undergoing tumorous surgery in a tertiary referral cancer center in China. Medicine. 96(17), e6794. https://doi.org/10.1097/MD.0000000000006794
5. Cook TM, Woodall N, Frerk C. Major complications of airway management in the UK: results of the 4th National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1 Anaesthesia. British Journal of Anaesthesia. 2011; 106: 617–31. https://associationofanaesthetists-publications.onlinelibrary.wiley.com/doi/10.1111/anae.14123
