ABSTRACT
Aim: We aimed to create a system for monitoring of regional cerebral oxygen saturation (rSO 2) in patients with prehospital cardiopulmonary arrest and clarify the changes in rSO 2 during cardiopulmonary resuscitation. Methods: We measured rSO 2 in cardiopulmonary arrest patients who were transferred by the emergency response vehicle of Nagasaki University Hospital. We developed a portable rSO 2 monitor (HAND ai TOS), which is small enough to carry during prehospital treatment. The sensor is attached to the forehead of the patient and monitors rSO 2 continuously during treatment and transfer. Results: No difficulties were experienced in monitoring rSO 2 during patient treatment and transfer. Median time (interquartile range) from the emergency medical service call to emergency response vehicle arrival was 15.0 min (11.0-19.5 min). Median rSO 2 on emergency response vehicle arrival at the scene was 46.3% (44.0-48.2%) (n = 9; median age, 74.0 years; four men, five women). Median rSO 2 showed significant increase within 5 min after return of spontaneous circulation (n = 6, 46.6% versus 58.7%, P < 0.05). There was no significant increase in rSO 2 during prehospital cardiopulmonary resuscitation until return of spontaneous circulation was established. Conclusions: We developed an rSO 2 monitoring system for use during prehospital cardiopulmonary resuscitation. The monitoring system showed a significant increase in rSO 2 after return of spontaneous circulation, whereas there was no significant increase in rSO 2 during cardiopulmonary resuscitation after intubation but before return of spontaneous circulation.