Materials and Methods
This was a multicenter retrospective study conducted in Jeddah, Saudi Arabia. This study was approved by the department of research and studies at the Ministry of Health in Saudi Arabia (registration no. H-02-J-002, approval no. A00440). Informed consent was waived due to the retrospective nature of the study. Researchers retrospectively collected data from cardiac arrest flowsheets from each site between January 2016 and January 2017. We included patients 1) ≥18 years-old, 2) non-shockable rhythms, 2) received intravenous Epinephrine during cardiopulmonary resuscitation, 3) witnessed in-hospital arrest, 4) only the first resuscitation attempt (for patients requiring more than one attempt) and 5) chest compression started within 1-min of recognition. We excluded patients who suffered traumatic arrest, were pregnant, had shockable rhythms, in the operating room, had a Do-Not-Resuscitate (DNR) order, and parents aged 17 years-old or less.
It is standard procedure in the Kingdom of Saudi Arabia to activate code blue in a hospital to mobilize the resuscitation team. The definition of cardiopulmonary arrest at each site is the cessation of cardiac function manifesting as a non-palpable carotid pulse. Upon recognition, personnel are required to call for assistance and immediately start chest compressions. Each site requires all medical staff to be certified in basic life support at the minimum. Code blue team is typically composed of a critical care physician, an anesthesiologist, an intensive care unit nurse, in addition to the primary team and staff nurse from the location of arrest. Team members responding to code blue activations are certified in advanced cardiac life support to ensure standardized treatment. The composition of the resuscitation team may differ from one institution to another based on staff expertise and patient needs. Epinephrine is always administered by the code blue team nurse at the discretion of the code blue team leader. Cardiopulmonary arrest flow sheets may differ in format between institutions; however, all contain the key information according to the Utstein guideline for documentation. Data included on the flow sheet include: patient information and demographics, time and date of arrest, location of arrest, available team members and time of response, initial and subsequent rhythms, medications and doses administered, type of airway device placed, presence or absence of return of spontaneous circulation, and post-arrest vital signs. The data is entered in real time during the resuscitation by a nurse designated and trained in documentation.
Time to epinephrine was defined as the interval in minutes from recognition of loss of pulse to the first bolus of 1 mg intravenous epinephrine. A registered nurse is delegated the task of documenting time intervals during resuscitation in all resuscitations. Each center provides special training for documenting events during resuscitation to ensure standardization. We defined sustained ROSC as sustained return of pulse for at least 24-h regardless of subsequent events during the 24-h period.
Descriptive statistics were used to characterize the study population. The Pearson's Chi Square test or independent T-test was used to compare variables between the immediate (within 1-min) epinephrine group with the early (> 2-min) epinephrine group. Furthermore, we constructed a logistic regression model analyzing the primary outcome of ROSC as an independent categorical variable according to the time of epinephrine administration to determine potential associations between confounding variables including age, gender, race, initial rhythm (PEA/asystole), CPR duration, endotracheal intubation during CPR (yes/no), institution (hospital A, B, C), level of care (emergency department, intensive care unit, floor), and diagnosis category (cardiac, respiratory, central nervous system, gastrointestinal, metabolic). Selection of these variables were planned a priori and based on previous studies. A p-value of less than 0.05 was considered significant. We reported the unadjusted and adjusted odds ratio with 95% confidence interval for statistical testing. Analyses were performed using the IBM SPSS statistical package for Windows, version 25.0, SPSS, Inc., Chicago, IL, USA.
BMC Anesthesiol. 2021;21(147) © 2021 BioMed Central, Ltd.