Central Venous Oxygen Saturation in Children With Cancer.

Objective: Central venous saturation (ScvO2) can guide resuscitation of children with septic shock. The normal range of ScvO2 is typically considered as 0.70-0.80, but has not been established in children with cancer. Children with cancer are particularly prone to develop sepsis due to their immunosuppressive therapy, and usually have a permanent central venous catheter, making ScvO2 readily available. We aimed to investigate normal values of ScvO2 in clinically stable children with cancer, and the association between ScvO2, hemoglobin, and lactate.

Methods: We conducted a prospective clinical study at the outpatient clinic of a tertiary pediatric hematology/oncology unit. Blood samples were collected from stable children aged 0-17.9 years who were treated for cancer between January 1 and November 30, 2019, during their routine outpatient clinic visits.

Results: A total of 183 blood samples were collected from 68 patients (24 girls and 44 boys). The predicted mean level of ScvO2 with a 95% confidence interval was 0.67 (0.56-0.78). The ScvO2 value was below the expected lower normal limit of 0.70 in 126 (69%) of the samples and in 48 patients (71%) at least once. ScvO2 was significantly associated with hemoglobin (β1 = 0.012 per g/L hemoglobin, P < 0.001), but not with age, sex, underlying diagnosis, or lactate.

Conclusions: The study revealed that a substantial portion of clinically stable childhood cancer patients exhibited ScvO2 levels below the typical reference value of 0.70, suggesting that these children may have inherently lower baseline ScvO2 levels. This should be kept in mind when evaluating children with cancer for septic shock, emphasizing the importance of tailored assessments in this population. Further understanding of baseline ScvO2 abnormalities may be helpful if ScvO2 is used to guide resuscitation.