Abstract
To investigate the use of two-site regional oxygen saturations (rSO(2)) and end tidal carbon dioxide (EtCO(2)) to assess the effectiveness of resuscitation and return of spontaneous circulation (ROSC). Eight mechanically ventilated juvenile swine underwent 28 ventricular fibrillatory arrests with open cardiac massage. Cardiac massage was administered to achieve target pulmonary blood flow (PBF) as a percentage of pre-cardiac arrest baseline. Non-invasive data, including, EtCO(2), cerebral rSO(2) (C-rSO(2)) and renal rSO(2) (R-rSO(2)) were collected continuously. Our data demonstrate the ability to measure both rSO(2) and EtCO(2) during CPR and after ROSC. During resuscitation EtCO(2) had a strong correlation with goal CO with r = 0.83 (p < 0.001) 95% CI [0.67-0.92]. Both C-rSO(2) and R-rSO(2) had moderate and statistically significant correlation with CO with r = 0.52 (p = 0.003) 95% CI (0.19-0.74) and 0.50 (p = 0.004) 95% CI [0.16-0.73]. The AUCs for sudden increase of EtCO(2), C-rSO(2), and R-rSO(2) at ROSC were 0.86 [95% CI, 0.77-0.94], 0.87 [95% CI, 0.8-0.94], and 0.98 [95% CI, 0.96-1.00] respectively. Measurement of continuous EtCO(2) and rSO(2) may be used during CPR to ensure effective chest compressions. Moreover, both rSO(2) and EtCO(2) may be used to detect ROSC in a swine pediatric ventricular fibrillatory arrest model.