Systemic and regional cerebral perfusion in small infants undergoing minor lower abdominal surgery under awake caudal anaesthesia: An observational study

BACKGROUND: Infants undergoing general anaesthesia have an increased risk of severe respiratory and cardiovascular critical events. Awake caudal anaesthesia is an alternative for small infants undergoing minor lower abdominal surgery. While clinical experience has shown stable intra-operative haemodynamic conditions, there are no studies evaluating systemic and regional cerebral perfusion during such a procedure. OBJECTIVES: The purpose of this study was to evaluate the effects of awake caudal anaesthesia on systemic and regional cerebral perfusion in small infants. DESIGN: A prospective observational cohort study. SETTING: Clinic of Anaesthesiology, University Children's Hospital, between November 2017 and June 2018. PATIENTS: Twenty small infants (postmenstrual age 36 to 54 weeks, weight 1800 to 5700 g) scheduled for lower abdominal surgery under awake caudal anaesthesia were enrolled in this study. INTERVENTION: Standard monitoring was expanded to include cardiac index using electrical velocimetry and regional cerebral oxygen saturation using near infrared spectroscopy. The caudal block was performed with 0.3% ropivacaine 1 ml kg Hypotension was defined as mean arterial blood pressure (BP) less than 35 mmHg and regional cerebral desaturation as regional cerebral oxygen saturation less than 80% of baseline. MAIN OUTCOMES: Mean arterial BP, cardiac index and regional cerebral oxygen saturation parameters under awake caudal anaesthesia. RESULTS: Mean arterial BP, cardiac index and regional cerebral oxygen saturation remained above the predefined lower limits. No episodes of hypotension or regional cerebral desaturation were observed. Operation time was 35 +/- 13 (range 20 to 71) min. The infants were discharged to the neonatal ward after the end of surgery, and milk was fed 22 +/- 15 (range 6 to 55) min thereafter. Five preterm infants experienced self-limiting episodes of apnoea intra-operatively. CONCLUSION: The current study shows that awake caudal anaesthesia does not impair systemic and regional cerebral perfusion in small infants. TRIAL REGISTRATION: German registry of clinical studies (DRKS-ID: 800015742).