Physiological monitoring and physiology-informed strategies in cardiac arrest: current evidence and clinical translation

Despite advances in cardiac arrest management, survival with favorable neurological outcomes remains limited. Physiological monitoring may complement standardized resuscitation by providing real-time information about circulatory effectiveness, reversible causes, and treatment responses. However, whether physiology-guided interventions improve patient-centered outcomes remains uncertain. This narrative review examines the current evidence and clinical applicability of physiological monitoring during resuscitation, physiology-informed rescue strategies, and individualized post-cardiac arrest care. During cardiopulmonary resuscitation, invasive arterial pressure monitoring, waveform capnography, and echocardiography provide complementary information about the circulation generated by chest compressions and potential mechanisms of resuscitation failure. Although observational and experimental studies support their physiological relevance, no adult diastolic pressure target or pressure-guided vasopressor strategy has been validated to improve survival or neurological recovery. Recent randomized trials of transesophageal echocardiography have demonstrated physiological or procedural effects without establishing clinical benefit. Among rescue strategies, extracorporeal cardiopulmonary resuscitation has yielded inconsistent results across randomized trials, with potential benefits dependent on patient selection, intervention timing, and system capabilities. Resuscitative endovascular balloon occlusion of the aorta has not improved clinical outcomes in randomized evaluation, while head-up resuscitation remains investigational. Following the return of spontaneous circulation, randomized trials have challenged the benefits of uniformly higher blood pressure and oxygenation targets, mild hypercapnia, and deeper or prolonged temperature control. Individualized approaches incorporating cerebral autoregulation, venous congestion, and cardiopulmonary physiology are physiologically appealing but lack prospective validation. Physiological assessment may complement established resuscitation algorithms by refining clinical decisions during and after cardiac arrest. However, improvements in physiological measurements should not be equated with improved patient outcomes. Future trials should determine whether predefined, physiology-guided treatment strategies improve survival and neurological recovery.