A new variant position of head-up CPR may be associated with improvement in the measurements of cranial near-infrared spectroscopy suggestive of an increase in cerebral blood flow in non-traumatic out-of-hospital cardiac arrest patients: A prospective interventional pilot study

Aim of the study This study aimed to investigate the effect of the head-up position implemented during cardiopulmonary resuscitation (CPR) on cerebral blood flow (CBF) using near-infrared spectroscopy in out-of-hospital cardiac arrest patients. Methods Baseline characteristics (age, sex, cerebral performance category before cardiac arrest, witnessed cardiac arrest, bystander CPR, first monitored rhythm, no-flow time, prehospital low-flow time, CPR duration in the emergency department (ED), and reason for stopping CPR in the ED) were recorded. The changes of CBF were derived from the optical oscillation waveform measured by near-infrared spectroscopy in adult patients with out-of-hospital cardiac arrest by alternating head-up and supine positions at 4-minute intervals while performing CPR. The CBF velocity according to the head position was also evaluated using the time derivative of the oscillation waveform. Results During the study period, 28 patients were enrolled. The median increase in CBF in the prefrontal area in the head-up position was 14.6% (Interquartile range, 8.8–65.0), more than that in the supine position. An increase in CBF was observed in the head-up position compared with the supine position in 83.3% of the patients included in the analysis. Conclusion CBF increased when the head-up position was used during CPR in non-traumatic out-of-hospital cardiac arrest patients.