Evaluation of Vena Cava Inferior Collapsibility Index With Ultrasonography in Children Undergoing General Anesthesia and Regional Anesthesia for Lower Abdominal and Urogenital Surgery

Abstract Background: Pediatric anesthetic management requires careful hemodynamic monitoring due to limited cardiovascular reserve and age-dependent physiological differences. Neuraxial anesthesia may affect hemodynamics differently from general anesthesia. Caudal anesthesia produces sympathetic blockade that may increase venous capacitance and alter venous return, potentially influencing intravascular volume distribution and preload. This study compared inferior vena cava (IVC) diameters and IVC distensibility (IVCDI) in children receiving general anesthesia alone versus combined general and caudal anesthesia. Methods: In this prospective observational study, 100 children aged 1–8 years scheduled for lower abdominal or urological surgery were enrolled. Patients were allocated based on parental consent: general anesthesia with caudal anesthesia (Group I, n=50) or general anesthesia alone (Group II, n=50). Induction was with sevoflurane in patients without intravenous access and propofol in those with access, followed by laryngeal mask airway placement and controlled mechanical ventilation. In Group I, caudal anesthesia was administered with 0.2% bupivacaine (0.8 mL/kg). IVC maximum (IVC max) and minimum (IVC min) diameters were measured, and IVCDI calculated using M-mode ultrasonography via a subxiphoid approach immediately after induction (T 0 ) and 20 minutes later (T 1 ). Results: Group I showed significant increases in IVC max and IVC min at T 1 , with a non-significant trend toward increased IVCDI, without adverse hemodynamic effects. No significant changes were observed in Group II. Heart rate remained stable and comparable between groups. Conclusion: In this study, caudal anesthesia combined with general anesthesia, at the doses used in our protocol, increased IVC diameters without significant changes in IVCDI or heart rate in mechanically ventilated children. These findings indicate increased venous capacitance without impaired preload responsiveness, supporting caudal anesthesia as a hemodynamically stable adjunct to general anesthesia in pediatric patients.