Questions of the Week for 11/14/23

Author: Christian Gerhart

When is the optimal time to obtain an EKG in a post-arrest patient?

• Answer

  The Post-ROSC Electrocardiogram After Cardiac Arrest [PEACE] study was a retrospective analysis, which demonstrated that an EKG obtained between 8-33 minutes post ROSC had increased accuracy compared to EKGs obtained <7 minutes after ROSC in post-arrest arrest patients. Post ROSC patients can have numerous EKG changes that may be due to ischemia from cardiac arrest itself rather than represent EKG changes from acute coronary syndrome. There may be times you will want to obtain an EKG immediately after ROSC, however it may be advisable to prioritize other interventions and try to obtain an EKG around minute 8 to maximize yield for identifying acute coronary syndrome. Another option is to obtain an initial EKG as soon as possible after ROSC with the knowledge that there may be false positives and repeat the EKG at around minute 10 post ROSC to assess for any changes.

A post-arrest patient has an EKG with lateral ST depressions but no ST elevations. You call cardiology for the patient to be considered for cardiac catheterization. When should coronary angiography be performed?

• Answer

  Patients with ST elevation myocardial infarction should go to the cardiac catheterization lab as soon as possible. However, patients with non-ST elevation myocardial infarction do not appear to have any significant difference in outcome when an immediate (within two hours) vs. delayed (within the first 24 hours) coronary angiography strategy is employed. The COACT study examined post-arrest patients with an initial shockable rhythm and did not find any significant difference in mortality between immediate or delayed angiography. The TOMAHAWK trial examined post-arrest patients of any initial rhythm and similarly found no significant mortality difference.

You have a 65 yo patient who presents with a bradycardic PEA arrest. They received 1 mg of epinephrine with EMS and on arrival have a pulse. They are intubated with an end tidal CO2 of 35. What diagnostic imaging would you obtain in this patient? 

• Answer

  All post-arrest patients should at least undergo a chest x-ray. CT imaging should be considered on a case-by-case basis. It may be useful to obtain a head CT to rule out a neurological cause for the patient’s arrest if the cause is not clear. One study4 estimated that approximately 1/20 non-traumatic, out of hospital cardiac arrests are caused by intracranial hemorrhage. This number may be even higher among females and those with non-shockable rhythms. Additionally, there is some evidence to suggest that obtaining a chest/abdomen/pelvis CT with contrast can be useful if the cause for the arrest is not known as well as to identify injuries caused by chest compressions. One study5 estimated that approximately 13% of cardiac arrests without an initially clear cause had a cause identified by their sudden death CT protocol (SDCT), which included a non-contrast CT head, a cardiac + thoracic gated CTA and a venous phase chest, abdomen pelvis.

You are still taking care of the patient above. Would you give them antibiotics?

• Answer

  There is not strong evidence regarding the use of antibiotics for patients who are post arrest. One study6 showed that a two-day course of ampicillin-sulbactam prevented ventilator-associated pneumonia, but did not have a statistically significant impact on mortality or ventilator free days. Other studies7,8 (one of them by our own Dr. Safa!) showed that there are high rates of bacteremia in post-arrest patients. It is unclear at this point if all post-arrest patients benefit from broad-spectrum antibiotics but it is a potential intervention to consider, especially if there is not an obvious other cause for their arrest.

You are in TCC and receive a page for an apneic patient with pinpoint pupils coming by EMS. You provide bag valve mask ventilation and give them a dose of IV naloxone and they wake up and are breathing spontaneously with normal vital signs. You check back a few minutes later after stabilizing the patient and he wants to leave. He admits to injecting heroin shortly prior to this. How long should this patient be observed after being reversed with Narcan?

• Answer

  There is considerable controversy on this topic. The duration of action of naloxone is estimated to be between 20-90 minutes, which is considerably shorter than many opioids that patients overdose on. Some authors have suggested that patients who receive naloxone for respiratory depression from opioid overdose should be observed for at least 4-6 hours to ensure stability9 , while others have suggested that this extended period may not be necessary10 assuming the patient has a normal mental status, is ambulatory, and shows no other signs of intoxication. A two-hour observation period seems to be reasonable and supported by evidence if it is thought that short-acting opioids were used11. However, if the patient endorses using a longer acting formulation, such as methadone, then an observation period of at least 24 hours is usually necessary.

1)    Baldi E, Schnaubelt S, Caputo ML, et al. Association of Timing of Electrocardiogram Acquisition After Return of Spontaneous Circulation With Coronary Angiography Findings in Patients With Out-of-Hospital Cardiac Arrest. JAMA Netw Open. 2021;4(1):e2032875. Published 2021 Jan 4. doi:10.1001/jamanetworkopen.2020.32875

2)    Lemkes JS, Janssens GN, van der Hoeven NW, et al. Coronary Angiography after Cardiac Arrest without ST-Segment Elevation. N Engl J Med. 2019;380(15):1397-1407. doi:10.1056/NEJMoa1816897

3)    Desch S, Freund A, Akin I, et al. Angiography after Out-of-Hospital Cardiac Arrest without ST-Segment Elevation. N Engl J Med. 2021;385(27):2544-2553. doi:10.1056/NEJMoa2101909

4)    Lee KY, So WZ, Ho JSY, et al. Prevalence of intracranial hemorrhage amongst patients presenting with out-of-hospital cardiac arrest: A systematic review and meta-analysis. Resuscitation. 2022;176:136-149. doi:10.1016/j.resuscitation.2022.05.001

5)    Branch KRH, Strote J, Gunn M, et al. Early head-to-pelvis computed tomography in out-of-hospital circulatory arrest without obvious etiology. Acad Emerg Med. 2021;28(4):394-403. doi:10.1111/acem.14228

6)    François B, Cariou A, Clere-Jehl R, et al. Prevention of Early Ventilator-Associated Pneumonia after Cardiac Arrest. N Engl J Med. 2019;381(19):1831-1842. doi:10.1056/NEJMoa1812379

7)    Abou Dagher G, Bou Chebl R, Safa R, et al. The prevalence of bacteremia in out of hospital cardiac arrest patients presenting to the emergency department of a tertiary care hospital. Ann Med. 2021;53(1):1207-1215. doi:10.1080/07853890.2021.1953703

8)    Coba V, Jaehne AK, Suarez A, et al. The incidence and significance of bacteremia in out of hospital cardiac arrest. Resuscitation. 2014;85(2):196-202. doi:10.1016/j.resuscitation.2013.09.022

9)    Boyer EW. Management of opioid analgesic overdose. N Engl J Med. 2012;367(2):146-155. doi:10.1056/NEJMra1202561

10) Willman MW, Liss DB, Schwarz ES, Mullins ME. Do heroin overdose patients require observation after receiving naloxone?. Clin Toxicol (Phila). 2017;55(2):81-87. doi:10.1080/15563650.2016.1253846

11)  Clarke SF, Dargan PI, Jones AL. Naloxone in opioid poisoning: walking the tightrope. Emerg Med J. 2005;22(9):612-616. doi:10.1136/emj.2003.009613