2025 Korean Guidelines for Cardiopulmonary Resuscitation: Part 4. Adult advanced life support

The 2025 Korean advanced life support guidelines were updated using a structured evidence evaluation process informed by recent randomized controlled trials and systematic reviews. The guideline development group prioritized patient-important outcomes and assessed the certainty of the evidence to formulate graded recommendations. For drug administration during adult cardiac arrest, intravenous access is the preferred initial route, with intraosseous access recommended when intravenous access cannot be rapidly established. Epinephrine remains the recommended vasopressor. Routine administration of vasopressin, either alone or in combination with corticosteroids, is not recommended for in-hospital or out-of-hospital cardiac arrest. In the absence of specific indications, the routine use of buffering agents and calcium is discouraged owing to insufficient evidence of their benefits and potential harm. Defibrillation recommendations were refined based on emerging evidence. In adults with refractory ventricular fibrillation or pulseless ventricular tachycardia after multiple unsuccessful defibrillation attempts, vector change or double sequential defibrillation may be considered in selected settings when performed by experienced teams with appropriate equipment. Airway management guidelines recommend cricothyroidotomy as a rescue technique when conventional airway management strategies fail. For patients receiving cardiopulmonary resuscitation while on mechanical ventilation, specific ventilator settings during chest compressions are recommended to optimize ventilation and minimize interference with high-quality cardiopulmonary resuscitation. The guidelines also address cardiopulmonary resuscitation-induced consciousness, allowing the cautious use of sedatives and/or analgesic agents when awareness interferes with resuscitation quality or safety. Overall, the guidelines emphasize evidence-based practice and individualized clinical decision-making.