Manual and Mechanical Chest Compression During In-hospital Witnessed Cardiac Arrests Using Cerebral Oximetry

The study will be a single-center, prospective and randomized study. It will be conducted at the Emergency Department of Eskisehir Osmangazi University Education, Application and Research Hospital.

Patients will be allocated to treatment groups by blocked randomization (www.randomizer.org). Advanced cardiac life support algorithm will be initiated as outlined in the current resuscitation guidelines and cardiopulmonary resuscitation (CPR) will be continued either manually or mechanically (with the chest compression system), according to the randomization scheme. Due to the nature of the interventions carried out in the study process, blinding of healthcare providers was not possible.

Before the initiation of the study, the team members participating in the study will receive theoretical and practical training on CPR, mechanical chest compression system utilization and NIRS.

Patients who develop cardiopulmonary arrest during their clinical evaluation in the emergency department will receive CPR, and the chest compression method will be determined by the senior physician according to the randomization scheme.

• The manual CPR group will receive chest compressions, respiratory support and medical treatment in accordance with the recommendations of current guidelines. If return of spontaneous circulation (ROSC) is achieved, post-resuscitation care will be provided. If ROSC is not achieved, CPR will be terminated in accordance with the recommendations of current guidelines.
• The patients on the mechanical chest compression group will receive manual chest compressions until the mechanical compression device is installed (about 15-20 seconds). In this time interval, thorax and sternum measurements will be evaluated for suitability for the study, and mechanical compression device will be installed on patients who are deemed suitable. The patients will receive chest compressions, respiratory support and medical treatment in accordance with the recommendations of current guidelines. If ROSC is achieved, post-resuscitation care will be provided. If ROSC is not achieved, CPR will be terminated in accordance with the recommendations of current guidelines.

The presence of ROSC or the decision to terminate CPR will be determined according to the vital signs (arterial blood pressure, heart rate, oxygen saturation with pulse oximeter), end tidal carbon dioxide (ETco2) measurement (with the module device used for the measurement of rSO2) and cardiac assessment with bedside ultrasonography (Vivid e, General Electric Healthcare, China).

As soon as cardiopulmonary arrest is identified, sensors measuring the value of rSO2 will be placed on the patient's head bifrontally (forehead area) in order to measure the cerebral perfusion. During CPR, rSO2 values will be continuously recorded. The placement of the sensors and the measurements will be carried out by a medical staff who received necessary training prior to the study. In order not to affect the clinical decisions made during CPR, the rSO2 device will be placed in a convenient area which is out of the CPR performers' eyesight.

Arterial blood pressure, heart rate, respiratory rate, body temperature, oxygen saturation on pulse oximeter, primary arrest rhythm, any known diseases (if existent) and defibrillation attempts (if existent) will be recorded on the case report form during CPR.

In patients with ROSC, 6-hour and 24-hour survival after CPR, discharge from the hospital with favorable neurologic outcome and the presence of additional pathologies (such as heart failure and neurologic sequelae) will be evaluated. Favorable neurologic outcome was defined as a Cerebral Performance Category score of 1-2. In patients with ROSC, post-resuscitation care will be provided as recommended in the current guidelines.

Inclusion criteria

• 18 years or older.
• In hospital (emergency service) witnessed cardiac arrest.
• Cardiac arrest caused reasons other than trauma.
• Length of sternum between 170- 303 mm (devise requirements).
• Patients' chest width not more than 449 mm (devise requirements).
• Informed consent of first-degree relatives of patients.

Exclusion criteria

• Younger than 18 years old.
• Out-of-hospital cardiac arrest.
• Exposure to trauma.
• Pregnancy.
• Length of sternum not between 170- 303 mm (devise requirements).
• Patients' chest width more than 449 mm (devise requirements).
• Intracranial mass, large infarct or bleeding in the frontal part of the head (rSO2 monitoring area) which might effect the evaluation.
• Lack of informed consent of first-degree relatives of patients.