Objective: To compare changes in hemodynamic parameters including systemic vascular resistance (SVR), cardiac output (CO), blood pressure (BP) and heart rate (HR) after caudal block in different age groups of children.
Material and Method: This single-center observational pilot study was conducted in ASA 1 to 2 children, less than 8 years of age who underwent surgeries under combined GA and caudal block from December 2013 to December 2014. Patients were divided into 3 groups (Group 1 = 0 to 1 years old, Group 2 = 1 to 3 years old, Group 3 = 3 to 8 years old). Hemodynamic parameters were measured with USCOM and compared at baseline and at 5, 10, and 15 minutes after caudal block with 1 mL/kg 0.25% bupivacaine.
Results: Total of 42 participants enrolled in this study (Group 1 = 11, Group 2 = 15, Group 3 = 16). CO, mean arterial blood pressure (MAP), and HR decreased after caudal block. HR and CO reductions were more pronounced in Group 3. MAP reduction was highest in Group 2. There was no reduction in SVR after caudal block in all groups.
Conclusion: No evidence of SVR reduction after caudal block in children less than 8 years old, which reflects immature sympathetic nervous system of this patient group. There were reductions in CO, MAP, and HR in these patients, especially in 3 to 8 years old. Future study with more participants is required to make conclusion.

Keywords: Caudal block, Pediatrics, Hemodynamic changes, USCOM