Head computed tomography scan following cardiac arrest

Differentiating between comatose patients resuscitated from acute coronary syndrome-associated and subarachnoid hemorrhage-associated out-of-hospital cardiac arrest

BACKGROUND

Upon initial evaluation in the emergency department (ED), it is often difficult to differentiate between comatose patients resuscitated following acute coronary syndrome (ACS)-associated and subarachnoid hemorrhage (SAH)-associated out-of-hospital cardiac arrest (OHCA). We assessed the clinical differences between resuscitated comatose ACS-OHCA and SAH-OHCA patients during initial evaluation in the ED.

METHODS

Data of 1259 consecutive OHCA patients were analyzed retrospectively. Of these, 23 resuscitated comatose ACS-OHCA patients and 20 resuscitated comatose SAH-OHCA patients were included in the final analysis. Clinical data obtained during initial evaluation in the ED were compared between groups.

RESULTS

Pulseless electrical activity (PEA) or asystole as the initial cardiac rhythm, female gender, and preserved left ventricular ejection fraction (≥50%) on the echocardiogram were significantly more common in the SAH-OHCA group (p<0.05 each). Although ST-T abnormalities suggesting myocardial damage (ST elevation and/or ST depression) were noted in most patients in both groups via 12-lead electrocardiogram (95%, ACS-OHCA group; 85%, SAH-OHCA group, p=0.50), reciprocal ST depression was significantly more often absent in the SAH-OHCA group (p=0.025). Initial PEA/asystole and presence of 1 other factor was sufficient to differentiate SAH-OHCA patients from ACS-OHCA patients (100% sensitivity, 91% specificity, 95% accuracy).

CONCLUSIONS

Initial ED evaluation is sufficient to differentiate between comatose ACS-OHCA and SAH-OHCA patients prior to further diagnostic work-up (e.g. emergent coronary angiography and head computed tomography).

Subarachnoid Hemorrhage Associated with Ventricular Fibrillation and Out-of-Hospital Cardiac Arrest

Aneurysmal subarachonoid hemorrhage (SAH) is a common cause of out-of-hospital cardiac arrest (OHCA). Even after successful resuscitation, most of these SAH patients suffer brain death or enter a vegetative state. To our knowledge, survival without neurological damage from SAH following OHCA is quite a rare event. We treated a case of SAH who presented with OHCA and survived without neurological sequelae. A 50-year-old woman presented with ventricular fibrillation (VF), and was successfully resuscitated before hospital arrival. Since there was no evidence of acute coronary syndrome, a head CT scan was performed and established the diagnosis of SAH. On arrival, she was comatose, however, 3 hours after admission, her neurological status recovered. She underwent treatment for the ruptured aneurysms and was discharged from hospital without any neurological deficits.

Headache, cardiac arrest, and intracranial hemorrhage

Headache is one of the most common manifestations of non-traumatic intracranial hemorrhage, which is an uncommon, but not rare, cause of cardiac arrest in adults. History of a sudden headache preceding collapse may be a helpful clue to estimate the cause of out-of-hospital cardiac arrest (OHCA). Medical records of witnessed OHCA patients were reviewed to identify those who complained of a sudden headache preceding collapse, and the incidence of intracranial hemorrhage among them as well as their clinical characteristics was investigated retrospectively. During the 12-month period, 124 patients who sustained a witnessed OHCA were treated. Among them, 74 (60%) collapsed without any pain complaint, and only 6 (5%) complained of a sudden headache preceding collapse. All of the six patients were resuscitated: four had a severe subarachnoid hemorrhage (SAH), while the other two had a massive cerebellar hemorrhage. By contrast, 39 of the 74 patients who collapsed without any pain were resuscitated. Among them, another six patients were found to harbor an SAH. Thus, a total of 12 among the 124 witnessed OHCA (10%) sustained a fatal intracranial hemorrhage. While OHCA patients who collapse complaining of a sudden headache are uncommonly seen in the emergency room, they have a high likelihood of harboring a severe intracranial hemorrhage. It should also be reminded that approximately half of patients whose cardiac arrest is due to an intracranial hemorrhage may collapse without complaining of a headache. The prognosis of those with cerebral origin of OHCA is invariably poor, although they may relatively easily be resuscitated temporarily. Focus needs to be directed to avoid sudden death from a potentially treatable cerebral lesion, and public education to promote the awareness for the symptoms of potentially lethal hemorrhagic stroke is warranted.