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.