Central Venous Oxygen Saturation in Children With Cancer

Central venous saturation (ScvO 2 ) can guide resuscitation of children with septic shock. The normal range of ScvO 2 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 ScvO 2 readily available. We aimed to investigate normal values of ScvO 2 in clinically stable children with cancer, and the association between ScvO 2 , hemoglobin, and lactate.

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.

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 ScvO 2 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. ScvO 2 was significantly associated with hemoglobin ( β 1 = 0.012 per g/L hemoglobin, P < 0.001), but not with age, sex, underlying diagnosis, or lactate.

The study revealed that a substantial portion of clinically stable childhood cancer patients exhibited ScvO 2 levels below the typical reference value of 0.70, suggesting that these children may have inherently lower baseline ScvO 2 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 ScvO 2 abnormalities may be helpful if ScvO 2 is used to guide resuscitation.