[Regularity of agonal respiration after untreated cardiac arrest in a swine model]

To explore the regularity of incidence of agonal respiration (AR) and agonal respiration frequency rate (ARFR) during untreated cardiac arrest (CA) after ventricular fibrillation (VF) in a swine model.

Ten healthy male domestic pigs weighing (25.0 ± 3.0) kg were employed in this experiment. VF was induced by intraventricular shock with alternating current without treatment for 8 minutes. The incidence of AR and ARFR per minute were recorded for 8 minutes. Statistical analysis was performed using SPSS 19.0 system software.

AR occurred in all animals after VF induced CA within 8 minutes. There was 1 animal showed AR at the first minute with ARFR (0.2 ± 0.1) times/min, 4 animals showed AR at the second minute with ARFR (1.2 ± 1.0) times/min, 7 animals showed AR at the third minute with ARFR (2.7 ± 1.4) times/min, all animals showed AR at the fourth to fifth minute with ARFR (3.7 ± 1.6) times/min and (3.2 ± 1.9) times/min, 7 animals showed AR at the sixth minute with ARFR (1.3 ± 1.0) times/min, no animal showed AR at the seventh minute, and 1 animal showed AR at the eighth minute with ARFR (0.2 ± 0.1) times/min. The first and the last AR were observed at (2.02 ± 0.84) minutes and (5.21 ± 1.12) minutes respectively. Occurrence of AR reached its peak at the fourth to fifth minute, and it was absent at the seventh minute. ARFR after CA showed a crescendo-decrescendo pattern, which increased from (0.2 ± 0.1) times/min to (3.7 ± 1.6) times/min followed by a fall to (0.2 ± 0.1) times/min.

AR is one of the symbolic signs after CA. AR occurred in all animals during untreated VF, and it reaches its peak at the fourth to fifth minute, with a crescendo-decrescendo pattern of ARFR. Effective identification and treatment in victim with AR timely can help to improve the success rate of cardiopulmonary resuscitation and survival rate.