Changes in carbon dioxide tension and oxygen saturation during sleep sedation for paediatric cardiac catheterization

The purpose of this observational study was to determine whether hypercarbia or oxygen desaturation occurred during our current regimens of deep sedation or general anaesthesia of infants and children undergoing cardiac catheterization. Data were gathered prospectively from 50 consecutive infants and children aged 4 months to 12 years undergoing cardiac catheterization. Several anaesthetists used the following regimens, which were not randomized: 1) propofol. 1.5-2.0 mg . kg(-1) and fentanyl 1 mu g . kg(-1) IV over 2 min for induction, followed by propofol infusion of 100-150 mu gk . g(-1). min(-1); 2) fentanyl 2-3 mu g . kg(-1) and midazolam 0.1-0.2 mg . kg(-1) IV over 10-15 min; 3) ketamine 8 mg . kg(-1) IM, or 4) same as regimens 1 or 2, plus pancuronium, intubation and controlled ventilation. Regimens 1, 2, and 3 were associated with spontaneous ventilation through the natural airway. End-tidal carbon dioxide tension (PetCO(2)), SpO(2), and respiratory rate were monitored for 60 min. The three regimens employing spontaneous ventilation through the natural airway were associated with both statistically and clinically significant increases in PetCO(2) and decreases in SpO(2). This raises the possibility that acute exacerbation of PAP and PVR may occur in pulmonary hypertensive patients. In contrast, PetCO(2) and SpO(2) did not change significantly from baseline in the controlled ventilation group.