A 14-month-old female patient was admitted for the laparoscopic excision of a complicated urachal cyst. General anesthesia was induced with thiopental and rocuronium and maintained with sevoflurane and the intermittent administration of vecuronium. During the insufflation of CO₂ her intra-abdominal pressure was maintained below 12 cmH₂O to avoid excessive hypercarbia. Thirty minutes after CO₂ insufflation initiation, end tidal CO₂ increased to 74 mmHg at a peak inspiratory airway pressure of 24 cmH₂O. Laparoscopic excision of the urachal cyst was performed within 2 hours without a further change in end tidal CO₂, blood pressure, heart rate, or O₂ saturation. Before extubation, O₂ saturation by pulse oxymetry was 99% and end tidal CO₂ was 45-50 mmHg. The patient was discharged without any problem 5 days after the operation. We report on this clinical experience and include a brief review of the literature.