Prognostic Value of Venous to Arterial Carbon Dioxide Difference and Mixed Venous Saturation during Early Resuscitation in Critically Ill Patients with Septic Shock

Ebrahim, Abd Elazeim Mamoon Dawoud; Ali, Essa Hamed Mohammed; Abd El Wahab, Essam Shafiq; Gad, Gamal Lofty Abd Rahman

doi:10.21608/ijma.2025.341956.2077

Prognostic Value of Venous to Arterial Carbon Dioxide Difference and Mixed Venous Saturation during Early Resuscitation in Critically Ill Patients with Septic Shock

Document Type : Original Article

Authors

Department of Anesthesiology, Intensive Care and Pain Management, Faculty of Medicine, Al-Azhar University, Cairo, Egypt.

10.21608/ijma.2025.341956.2077

Abstract

Background: Sepsis, its severe form and septic shock are among major healthcare challenging problems. Each year, millions of people are affected all over the world, and the mortality rate is one in four [and often more].
Aim of the work: The study aimed to evaluate the prognostic value of venous to arterial carbon dioxide [CO2] difference and mixed venous saturation during early resuscitation of critically ill patients with septic shock.
Patients and methods: This prospective cohort study was carried out on 35 patients aged from 18 to 60 years old, both sexes, with septic shock. They were selected from intensive care units of Al Azhar University. Patients were divided into two groups: Group I for survivors [n=21], and Group II for non-survivors [n=14].
Results: The severity of illness, rather than demographic factors or comorbidities, is a critical predictor of outcomes in septic shock patients. Non-survivors when compared to survivors exhibited higher APACHE II scores and significant physiological differences [including elevated heart rate, respiratory rate, temperature, and lower mean arterial pressure at T6]. They also had worse acid-base balance, lower oxygenation, and higher serum lactate levels. Both partial pressure of carbon dioxide in venous blood [PvaCO2] and Mixed venous oxygen saturation [ScvO2] were significant predictors of mortality. With a PvaCO2 cutoff of 6.05 mmHg, the sensitivity was 58.5%, specificity was 81.5% at T6. However, at a cutoff of 67% of ScvO2, the sensitivity was 68%, specificity was 76% at T6.
Conclusion: Partial pressure of carbon dioxide in venous blood and Mixed venous oxygen saturation are valuable predictors of mortality, and emphasizes the importance of early identification, continuous monitoring, and aggressive management of high-risk patients to improve outcomes.

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