Objective: To determine the relationship between venoarterial carbon dioxide gradient (ΔpCO2) and central venous oxygen saturation (ScvO2) in children after cardiac surgery. Study Design: A cohort study. Place and Duration of Study: The Paediatric cardiac intensive care unit of the Aga Khan University Hospital, Karachi, from June 2006 to May 2007. Methodology: All children admitted in the paediatric cardiac intensive care after complete repair of congenital heart defect using cardiopulmonary bypass were included in the study. Simultaneous arterial and central venous blood gas samples were obtained from a catheter placed in the artery (either radial or femoral) and superior vena cava respectively. Linear regression analysis was performed between ScvO2 and ΔpCO2. Results: Fifty seven children aged from 5 days to 14 years were included and 272-paired simultaneous arterial and central venous samples were analyzed. Mean venous pCO2 was 47.82±9.03 mmHg and mean arterial pCO2 was 40.50±9.06 mmHg. One hundred seventy four samples had ScvO2 > 70% with mean ΔpCO2 of 5.44±2.55 mmHg and 98 samples had ScvO2 < 70% with mean ΔpCO2 of 9.07±3.90 mmHg. With ScvO2 < 70%, 77 samples had ΔpCO2 of > 6 mmHg while only 21 samples had ΔpCO 2 of < 6 mmHg (p < 0.001). On the contrary with ScvO 2 > 70%, 71 samples had ΔpCO2 of > 6 mmHg and 103 samples had ΔpCO2 of < 6 mmHg. Coefficient of correlation (R2) between 0.340 was ScvO2 and ΔpCO2. Conclusion: Elevated ΔpCO2 is practical and can be utilized as a useful adjunct to low ScvO2 in the assessment of low cardiac output syndrome in children after cardiac surgery.
|Number of pages||4|
|Journal||Journal of the College of Physicians and Surgeons--Pakistan : JCPSP|
|Publication status||Published - Oct 2009|
- Cardiac output
- Central venous oxygen saturation
- Veno-arterial pCO difference