Timing for Computed Tomography and Post-Resuscitation Care on Short-Term Outcomes in Out-of-Hospital Cardiac Arrest

This retrospective multicenter study investigates the association between the timing of computed tomography (CT) scans and short-term outcomes in adult non-traumatic out-of-hospital cardiac arrest (OHCA) patients who achieved return of spontaneous circulation (ROSC). The study includes cases from January 1, 2016, to August 31, 2024, across six branches of National Taiwan University Hospital. Data collected include demographics, Utstein variables, emergency department (ED) interventions and their timing. Primary outcomes are survival to admission, and 1-day, 3-day, and 7-day survival. Secondary outcomes focus on the timing and sequence of CT imaging and other interventions in relation to short-term prognosis and ED length of stay. The study aims to explore whether earlier CT utilization can improve outcomes in the post-resuscitation phase of care.

Out-of-hospital cardiac arrest (OHCA) patients with return of spontaneous circulation (ROSC) would suffer from an inflammatory response in the body due to hypoxia and subsequent reperfusion injury, known as post-cardiac arrest syndrome (PCAS). Prompt interventions were crucial during this phase at the emergency department. Typically , these patients require rapid computed tomography (CT) scans. CT scans of different body parts aid in diagnosing serious infections (e.g., pneumonia, perforated peptic ulcer) and vascular emergencies (e.g., stroke, intracranial hemorrhage, aortic dissection, aneurysm, pulmonary embolism), enabling timely specialist intervention, catheterization, or surgery. Patients with traumatic cardiac arrest also require CT scans to identify the mechanism of fatal injuries and assess the current injury status.

Theoretically, the ED team would prefer to perform CT scans as quickly as possible after resuscitation. However, PCAS can result in unstable vital signs, and transporting unstable patients to the CT room, with limited resuscitation equipment, carries the risk of recurrent cardiac arrest. As a result, the patient's vitals are stabilized at ED before receiving the CT scan. However, delaying the scan also impedes diagnosis and treatment, prolonging the patient's unstable condition and creating a vicious cycle. Currently, there is no consensus or standard regarding the optimal timing for CT scans after resuscitation, with most literature focusing on brain CT scans. Thus, whether the timing and prioritization of CT scans can break this vicious cycle remains an area requiring further research.

This retrospective study is part of a sequential research effort by our team. We plan to include non-traumatic adult OHCA patients from January 2016 to August 2024 (2016/01/01 to 2024/08/31). The patient population will be drawn from NTU Hospital and its affiliated branches (Hsinchu, Biomedical, and Zhudong) and NTU Yunlin Branch (Huwei and Douliu), covering six hospital areas across three hospitals. Study variables include basic demographics, Utstein Style OHCA registry variables, ED interventions and their timing. Primary outcomes include survival to hospital admission, 1-day, 3-day, and 7-day survival rates. Secondary outcomes will examine the timing of CT scans, the sequence of other interventions, and their relationship to short-term survival and ED length of stay.

Eligibility Criteria:
Inclusion Criteria:

1. Adults aged 20 years or older.
2. Patients who experienced out-of-hospital cardiac arrest (OHCA), received resuscitative efforts in the emergency department, achieved return of spontaneous circulation (ROSC), and subsequently underwent computed tomography (CT) imaging (regardless of the anatomical region scanned).

Exclusion Criteria:

1. Patients with cardiac arrest due to traumatic causes (traumatic OHCA).
2. Patients who were transferred to non-NTUH-affiliated hospitals for post-resuscitation care.
3. Patients whose prognosis could not be determined from medical records.
4. Patients with incomplete, missing, or otherwise restricted medical records that limited data accessibility or review.