Background: To analyze the predictive value of the preoperative complete blood count components on the occurrence of surgical site infection (SSI) after elective cesarean section.
Methods: We conducted a retrospective case control study in a tertiary care hospital located in New York City during the period of November 1, 2018, to October 30, 2020. We included patients who developed SSI after elective cesarean section as cases and patients who did not develop SSI as controls. We tested the ability of neutrophil, lymphocyte, platelet, hemoglobin, hematocrit, total white blood cells, neutrophil to lymphocyte ratio, hemoglobin to platelet ratio, platelet to lymphocyte ratio, platelet to neutrophil ratio, platelet to hemoglobin ratio and neutrophil to hemoglobin ratio to identify the occurrence of SSI after cesarean section.
Results: We compared ten cases and 20 controls. The median lymphocyte and lymphocyte to hemoglobin ratio were statistically significantly higher in cases compared to controls (P=0.049 and P=0.04, respectively). A lymphocyte value higher than 1.5 x103/µL was the best cut-off to exclude the occurrence of SSI, with a sensitivity of 95%, a specificity of 50%, a positive predictive value of 5.5% and a negative predictive value of >99%. A lymphocyte to hemoglobin ratio higher than 1.13 was the best cut off to exclude the occurrence of SSI, with a sensitivity of 95%, a specificity of 60%, a positive predictive value of 6.8% and a negative predictive value >99%.
Conclusions: The preoperative lymphocyte and lymphocyte to hemoglobin ratio should be incorporated into patient counseling and preoperative algorithms to identify patients who will develop SSI. The biological mechanisms involved remain to be investigated and our data should be confirmed by further and larger studies.