Central Venous to Arterial Co 2 Difference After Cardiac Surgery in Infants and Neonates*

Abstract

Objective Venous to arterial carbon dioxide difference (AVCO2) correlates with cardiac output (CO) in critically ill adults, but its utility in pediatric patients is unclear. We sought to correlate AVCO2 with other CO surrogates (arteriovenous oxygen saturation difference [AVO2], central venous oxygen saturation [ScVO2], and lactate); as well as investigate its capacity to predict poor outcomes associated with low cardiac output (LCOS) in infants after cardiac surgery with cardiopulmonary bypass (CPB). Design Retrospective chart review. Poor outcome was defined as any: inotrope score > 15; death, cardiac arrest, ECMO, unplanned surgical re-intervention. Setting Pediatric cardiovascular intensive care unit Patients 139 infants <90d who underwent CPB, from October 2012 to May 2015. Measurement and Main Results 296 arterial and venous blood gas pairs from admission (n=139), 6hrs (n=62), 12hrs (n=73), 24hrs (n=22) were included in analysis. For all pairs, AVCO2 was moderately correlated with AVO2 (R2= 0.53, p<0.01) and ScVO2 (R2= −0.43, p<0.01), but not lactate. On admission AVCO2 was also moderately correlated with ScVO2 (R2= 0.-0.40, p<0.01) and AVO2 (R2= 0.55, p<0.01), but not lactate. 34/139 neonates (24.5%) had poor outcome. Median admission AVCO2 was 5.9 mm Hg (3.8, 9.2). Patients with poor outcome had median admission AVCO2 8.3 mmHg (5.6, 14.9) vs. 5.4 (3.0, 8.4) in those without poor outcome. AVCO2 (AUC=0.69, p<0.01), serum lactate (AUC=0.64, p=0.02) and ScVO2 (AUC=0.74, p<0.01) were predictive of poor outcome. After controlling for covariates, admission AVCO2 remained significantly associated with poor outcome [OR 1.3, 95% CI: 1.1–1.45], including independent association with mortality, [OR 1.2 (95% CI 1.07–1.31)]. Conclusions AVCO2 is correlated with important surrogates of CO, and is associated with poor outcome and mortality related to LCOS after cardiac surgery in infants. Prospective validation of these findings, including confirmation that AVCO2 can identify LCOS in real-time is warranted.

Utilidad de las medidas derivadas de la presión parcial de CO2 en pacientes adultos sometidos cirugía cardíaca con circulación extracorpórea

“…Por consenso entre 3 autores se excluyó el estudio de Cavaliere [20] dado que su objetivo fue evaluar cómo se afecta la capacidad de transporte de CO 2 durante la CEC, pero no cumplía con los objetivos de la revisión. Dos estudios que cumplían los principales objetivos fueron descartados ya que estudiaban pacientes pediátricos [23], [24].…”

The relationship between inotropic support therapy and central partial pressure of venous-arterial carbon dioxide after cardiopulmonary bypass

“…In addition, Naik et al [24] reported that serum lactate levels increased from the onset of CPB to peak and remained high up to six hours in the ICU and returned to normal by 24 hours. In a study on infants and neonates undergoing cardiac surgery, Rhodes et al [25] reported that ΔPCO 2 continued to increase within the first 24 hours after admission to ICU compared with admission levels, while patients remaining on inotropes at 24 hours showed a trend toward higher 24-hour ΔPCO 2 compared with patients who were weaned off inotropes. Changes in ΔPCO 2 over time could be related to high CO 2 production or changes in each factor determining the relationship between partial CO 2 pressure and CO 2 content.…”

Veno-Arterial Partial Pressure of Carbon Dioxide Difference as a Metric of Systemic Oxygen Delivery: Insights from a Correlative Meta-Analysis

“…These four studies included data from 350 unique pediatric patients who had undergone cardiac surgery. [17][18][19][20] As data from multiple blood gas pairs were utilized by several studies, data were pooled from a total of 809 blood gas pairs. The mean patient age was 252 days (8.4 months), while the mean patient weight was 7.0 kg.…”