• Modeling Mechanism：

  Potassium chloride (KCl), as a potassium supplement, has the following core mechanism of action: ① Excessive intravenous infusion of KCl rapidly increases the concentration of potassium ions in the blood, disrupting the potassium ion balance across the myocardial cell membrane; ② High potassium levels inhibit the opening of sodium channels in the myocardial cell membrane, prolonging the action potential duration, blocking atrioventricular conduction, and inducing arrhythmias (such as ventricular tachycardia and ventricular fibrillation), ultimately leading to sudden cessation of cardiac electrical activity.

• Related Products：

  Potassium chloride (T65401)

• Modeling Method：

  Experimental Subject：

  Pigs, Crossbred pigs (Landrace/Yorkshire/Duroc), Female, Body weight 38–42 kg, 3 months old

  Dosage and Administration Route：

  ① Preoperative preparation:
  - Anaesthetic induction: Intramuscular premedication with midazolam (1 mg/kg), followed by supplemental midazolam (0.625 mg/kg)+S - Ketamine (6.25 mg/kg)+Atropine (0.5 mg), intravenous infusion of Fentanyl (15-29 μg/kg/hr)+Propofol (4.0-5.5 mg/kg/hr) for maintenance anaesthesia;
  - Life support: Tracheal intubation (6.5 mm tube), mechanical ventilation (tidal volume 8 mL/kg, PEEP 5 cm H₂O), continuous infusion of lactated Ringer's solution (1 mL/kg/h)+unfractionated heparin (18 IU/kg/h) for volume maintenance and thromboprophylaxis;
  ② Core Modelling: Continuous intravenous infusion of Potassium chloride solution via venous access, rate adjusted as required until cardiac arrest occurs (ECG showing pulseless electrical activity or ventricular fibrillation, sustained aortic pressure < 20 mmHg);
  ③ Control group:
  - Blank control: Infusion of equivalent volume saline solution, with all other procedures identical;

  Dosing Frequency and Duration Model：

  Potassium chloride administration: Single continuous infusion until cardiac arrest occurs

• Validation：

  1. Electrophysiological parameters (core validation): - Electrocardiogram (ECG): Ventricular arrhythmias (ventricular tachycardia, ventricular fibrillation) are observed, eventually transitioning to pulseless electrical activity or a flat line, consistent with ECG characteristics of cardiac arrest; - Hemodynamics: Aortic pressure drops sharply to < 20 mmHg, coronary perfusion pressure is significantly reduced, and cardiac output (CO) approaches 0; 2. Biochemical parameters: - Arterial blood gas analysis: Serum potassium concentration is significantly elevated (≥6.5 mmol/L, normal reference range 3.5-5.5 mmol/L), which may be accompanied by metabolic acidosis (pH < 7.35); 3. Resuscitation response: - Defibrillation (360 J bidirectional defibrillation) or epinephrine (0.02 mg/kg) intervention is required to restore spontaneous circulation (ROSC), validating model stability.

*Precautions：

*References：Eggertsen MA,et,al. Sodium Bicarbonate and Calcium Chloride for the Treatment of Hyperkalemia-Induced Cardiac Arrest: A Randomized, Blinded, Placebo-Controlled Animal Study. Crit Care Med. 2024 Feb 1;52(2):e67-e78.