Modeling cardiac arrest and resuscitation in the domestic pig

Table 1 Details of representative cardiac arrest protocols in pigs

Ref.	Lurie et al[93], 2002	Mayr et al[38],2004	Tang et al[25],2006	Li et al[94],2008	Indik et al[95], 2009	Hang et al[96],2014
Pre-anesthetic, induction anesthetic	Ketamine 20 mg/kg im Propofol 2.3 mg/kg iv	Ketamine 20 mg/kg im Propofol 1-2 mg/kg iv Piritramide 30 mg iv	Ketamine 20 mg/kg im Pentobarbital 30 mg/kg iv	Ketamine 20 mg/kg im Pentobarbital 30 mg/kg iv	5% isoflurane	Ketamine 15 mg/kg im Midazolam 0.5 mg/kg im Atropine 0.05 mg/kg im Propofol 1 mg/kg iv
Maintenance anesthesia	Propofol 10 mg/kg per hour iv	Isoflurane (1%-2%) in 65% nitrous oxide	Pentobarbital 8 mg/kg per hour iv	Pentobarbital 8 mg/kg per hour iv	1.5%-3% isoflurane	Propofol 9 mg/kg per hour iv Fentanyl 1 μg/kg per hour iv
Method of arrest	Electrical: 60 Hz, 140-160 V	Pharmacological: 5 mg/kg bupivacaine	Electrical: 1-2 mA	LAD balloon occluder	Steel plug in LAD	Asphyxiation: endotracheal clamping
Pre-CPR arrest	6 min	6 min	7 min	5 min	8 min	8 min
Precordial compressions (% of chest diameter)	Mechanical: 80/min (25%)	Manual: 100/min	Mechanical: 100/min (25%)	Mechanical: 100/min (Group 1 25%, Group 2 17.5%)	Manual: 100/min (c. 33%)	Manual: 100/min (c. 33%)
CPR duration	6 min	2 min	1 min	3 min	2 min	4 min
Ventilation during CPR?	FIO2 = 1.0; 5:1 compression: ventilation	FIO2 = 1.0	FIO2 = 1.0; 15:2 compression: ventilation	FIO2 = 1.0; 15:2 compression: ventilation	None	FIO2 = 1.0; 12 cycles/min; 10 mL/kg per cycle
Countershocks	1-3 x 200 J	3, 4, 6 J/kg	150-360 J	150 J	150 J	4 J/kg
CPR between countershocks	90 s	None	1 min/shock	3 min	2 min	2 min
Vasopressors to enhance CPR	EPI 0.045 mg/kg	AVP 0.4 or 0.8 U/kg ± EPI 45 or 200 μg/kg	None	None	EPI 0.02 μg/kg; 1-3 doses	EPI 0.02 μg/kg
Definition of ROSC	Systolic BP > 70 mmHg	Systolic BP ≥ 80 mmHg for ≥ 5 min	Mean aortic BP > 60 mmHg for ≥ 5 min	Mean aortic BP ≥ 60 mmHg for ≥ 5 min	Systolic BP > 50 mmHg for > 1 min	Systolic BP > 50 mmHg for > 10 min
ROSC duration	24 h	1 h	3 d	72 h	24 h	6 h
Pigs completing protocol	11/20	Placebo: 0/7; AVP: 5/7; EPI: 4/7; AVP + EPI: 7/7	36/44	Group 1: 6/6 Group 2: 0/6	11/15	ROSC: 8/16; Complete protocol: 3/16

AVP: Vasopressin; BP: Systemic arterial blood pressure; CPR: Cardiopulmonary resuscitation; EPI: Epinephrine; LAD: Left anterior descending coronary artery; ROSC: Recovery of spontaneous circulation.