Changes in respiratory and hemodynamic parameters during low-dose propofol sedation in combination with regional anesthesia for herniorrhaphy and genitourinary surgery in children

Background: Spontaneous vs mechanical ventilation during propofol sedation has been a subject of debate. We evaluated the safety of low-dose propofol sedation as an adjunct to regional anesthesia during herniorrhaphy and genitourinary surgery in infants and children. Methods: The study was conducted in a prospective, nonrandomized manner using a consecutive sample of 62 American Society of Anesthesiologists physical status class I patients between 5 months to 11 years of age in the surgery unit of an urban University Hospital. Propofol sedation (4-8 mg·kg^-1·h^-1 continuous infusion) was used with regional anesthesia (caudal, ilioinguinal/ iliohypogastric nerve or penile block with 0.2-0.375% ropivacaine). All children were spontaneously breathing without an anesthesia circuit. Respiratory and hemodynamic parameters were continuously recorded on all patients. One-way analysis of variance (anova) for repeated measurements was used to analyze changes in respiratory and hemodynamic parameters during the procedure. Results: Spontaneous ventilation was maintained in all patients with minimal changes in hemodynamic parameters. Heart rate, mean arterial pressure, and P _ECO₂ remained stable throughout the study period: 23/62 (37%) patients exhibited signs of developing intrinsic endexpiratory pressure (PEEPi) or the presence of PEEPi because of progressive reduction of expiratory time. Conclusions: Low-dose propofol sedation in combination with regional anesthesia for elective herniorrhaphy and genitourinary surgery in children maintains spontaneous ventilation and has minimal effects on hemodynamic parameters for sedation lasting <1 h. The presence of PEEPi is a relative contraindication to the use of this regimen in children with asthma or history of upper airway infections.