Table 1.
Summary of studies exploring different CC rates and C:V ratios in neonatal resuscitation.
| Reference | Design | Subjects | Interventions | Outcomes | Conclusion |
|---|---|---|---|---|---|
| Solevåg et al. (13) | Randomized controlled animal trial | Piglets 1–3 days of age weight 1.7–2.4 kg (n = 32) | Asphyxiated piglets were randomized to 3:1 C:V CPR or CCaV CPR (CC rate 90/min) | Time to ROSC was similar for 3:1 C:V CPR and CCaV CPR; p = 0.84 | Overall recovery may be similar, but CCaV might impair myocardial perfusion compared to 3:1 C:V CPR |
| Post mortem analysis of left ventricle lactate was increased in the CCaV group | |||||
| Solevåg et al. (11) | Randomized controlled animal trial | Piglets 12–36 h old (n = 32) | Asphyxiated piglets were randomized to receive a C:V ratio of 3:1 or 9:3 | Time to ROSC (median and interquartile range) was 150 (115–180) s vs. 148 (116–195) s for 3:1 and 9:3, respectively (p = 0.74). There were no differences in diastolic blood pressure (DBP) during compression cycles or in markers of hypoxia and inflammation | The C:V ratio 9:3 was not better than 3:1 |
| Solevåg et al. (12) | Randomized controlled animal trial | Piglets 12–36 h old (n = 22) | Asphyxiated piglets were randomized to receive a C:V ratio 3:1 or 15:2 | Mean (SD) increase in DBP (mmHg) during compression cycles was significantly higher with 15:2 than 3:1 C:V [7.1 (2.8) vs. 4.8 (2.6)]. Median (interquartile range) time to ROSC for the 3:1 group was 150 (140–180) s, and 195 (145–358) s for the 15:2 group | The C:V ratio 15:2 is not better than 3:1 in neonatal resuscitation |
| Dannevig et al. (9) | Randomized controlled animal trial | Piglets 12–36 h old (n = 94) | Asphyxiated piglets were resuscitated with a C:V ratio of 3:1, 9:3, or 15:2 | Interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and S100 in CSF, and gene expression of matrix metalloproteinases (MMPs), intercellular adhesion molecule-1 (ICAM-1), caspase 3, IL-6 and TNF-α in hippocampus and frontal cortex tissue were similar across C:V groups | Higher C:V ratios did not change the brain inflammatory response compared with the 3:1 C:V ratio |
| Dannevig et al. (17) | Randomized controlled animal trial | Piglets 12–36 h old (n = 72) | Asphyxiated piglets were resuscitated with a C:V ratio of 3:1, 9:3, or 15:2 | IL-8 and TNF-α in BAL fluid and MMP2, MMP9, ICAM-1, and TNFα in lung tissue were similar across C:V groups | Higher C:V ratios did not change the lung inflammatory response compared with the 3:1 C:V ratio |
| Boldingh et al. (30) | Randomized crossover manikin trial | Doctors, nurses, and midwifes (n = 34) | 5 min CPR, with either a 3:1 C:V ratio or CCaV (CC rate 120/min). All participants performed all interventions in a randomized order | The CC proportion with adequate depth was 90.5% for the 3:1 C:V ratio and 60.1% in CCaV | CCaV is more exhausting than a 3:1 C:V ratio |
| CCaV resulted in a greater increase in rescuer heart rate and mean arterial blood pressure, and perceived fatigue, compared to 3:1 C:V CPR | |||||
| Li et al. (28) | Randomized crossover manikin trial | Neonatologists, neonatal-perinatal fellows, neonatal nurse practitioners, and registered nurses (n = 30) | 10 min CPR with a 3:1 C:V ratio, CCaV-90 (CCaV at a 90/min rate), and CC at a rate of 120/min (CCaV-120) (CCaV at a 120/min rate). All participants performed all interventions in a randomized order | Peak CC pressure decreased significantly after 156, 96, and 72 s in the 3:1, CCaV-90, and CCaV-120 groups, respectively | 3:1 C:V CPR was the least fatiguing and the most preferred method |
| Boldingh et al. (29) | Randomized crossover manikin trial | Doctors, nurses, midwives, and last-year medical students (n = 84) | 2 min of CPR with C:V ratios 3:1, 9:3, or 15:2—and CCaV (CC rate 120/min). All participants performed all interventions in a randomized order | 3:1 C:V and 9:3 C:V were comparable in terms of CC and ventilation dynamics | The results of the study support the currently recommended 3:1 C:V ratio |
| The 15:2 C:V ratio resulted in less ventilation vs. the 3:1 C:V ratio | |||||
| The mean CC depth with CCaV vs. the 3:1 method was 32.7 vs. 34.6 mm (p < 0.001) | |||||
| There was a significant decrease in CC depth from baseline after 60 s (p = 0.025) with CCaV | |||||
| The two-person CRP coordination was rated easiest with the 3:1 C:V ratio | |||||
| Solevåg et al. (31) | Randomized crossover manikin trial | Two medical students | Ten times 2 min 3:1 C:V CPR, 9:3 C:V, and 15:2 C:V—and CCaV (CC rate 120/min) were performed in a randomized order | Minute ventilation in mL/kg was significantly lower at the C:V ratios 9:3 [140 (134–144)] and 15:2 [77 (74–83)] vs. 3:1 [191 (183–199)] | Higher C:V ratios than 3:1 compromised ventilation |
CC, chest compression; CPR, cardiopulmonary resuscitation; CCaV, continuous chest compression and asynchronous ventilation; ROSC, return of spontaneous circulation; CSF, cerebrospinal fluid; BAL, bronchoalveolar lavage.