Effect of ventilation rate on recovery after cardiac arrest in a pediatric animal model

PLoS One. 2020 Aug 20;15(8):e0237736. doi: 10.1371/journal.pone.0237736. eCollection 2020.

Abstract

Aims: To assess the impact of two different respiratory rates in hemodynamic, perfusion and ventilation parameters in a pediatric animal model of cardiac arrest (CA).

Methods: An experimental randomized controlled trial was carried out in 50 piglets under asphyxial CA. After ROSC, they were randomized into two groups: 20 and 30 respirations per minute (rpm). Hemodynamic, perfusion and ventilation parameters were measured 10 minutes after asphyxia, just before ROSC and at 5, 15, 30 and 60 minutes after ROSC. Independent medians test, Kruskal-Wallis test and χ2 test, were used to compare continuous and categorical variables, respectively. Spearman's Rho was used to assess correlation between continuous variables. A p-value <0.05 was considered significant.

Results: Arterial partial pressure of carbon dioxide (PaCO2) was significantly lower in the 30 rpm group after 15 minutes (41 vs. 54.5 mmHg, p <0.01), 30 minutes (39.5 vs. 51 mmHg, p < 0.01) and 60 minutes (36.5 vs. 48 mmHg, p = 0.02) of ROSC. The percentage of normoventilated subjects (PaCO2 30-50 mmHg) was significantly higher in the 30 rpm group throughout the experiment. pH normalization occurred faster in the 30 rpm group with significant differences at 60 minutes (7.40 vs. 7.34, p = 0.02). Lactic acid levels were high immediately after ROSC in both groups, but were significantly lower in the 20 rpm group at 30 (3.7 vs. 4.7 p = 0.04) and 60 minutes (2.6 vs. 3.6 p = 0.03).

Conclusions: This animal model of asphyxial CA shows that a respiratory rate of 30 rpm is more effective to reach normoventilation than 20 rpm in piglets after ROSC. This ventilation strategy seems to be safe, as it does not cause hyperventilation and does not affect hemodynamics or cerebral tissue perfusion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Arterial Pressure / physiology
  • Asphyxia* / physiopathology
  • Asphyxia* / therapy
  • Carbon Dioxide / metabolism
  • Disease Models, Animal
  • Heart Arrest* / physiopathology
  • Heart Arrest* / therapy
  • Lactic Acid / metabolism
  • Pediatrics
  • Respiratory Rate* / physiology
  • Statistics, Nonparametric
  • Swine / physiology
  • Ventilation* / standards

Substances

  • Carbon Dioxide
  • Lactic Acid

Grants and funding

This study was performed with a grant support from Carlos III Health Institute (PI15/00743), and Mother-Child Health and Development Network (Red SAMID), RETICS funded by the PN I+D+I 2013-2016 (Spain), Carlos III Health Institute - Sub-Directorate General for Research Assessment and Promotion and the European Regional Development Fund (ERDF), ref. RD16/0022. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.