Confirmed cardiac output on emergency medical services arrival as confounding by indication: an observational study of prehospital airway management in patients with out-of-hospital cardiac arrest

• Atsushi SakuraiNihon University
• Kosaku KinoshitaNihon University
• Yukihiro MaedaNihon University
• Yosuke HommaTokyo Bay Urayasu Ichikawa Medical Center
• Yoshio TaharaNational Cerebral and Cardiovascular Center Hospital
• Naohiro YonemotoKyoto University
• Ken NagaoNihon University
• Arino YaguchiTokyo Women's Medical University
• Naoto MorimuraThe University of Tokyo