Objective: To assess changes in ventilatory parameters, lung mechanics, cardiovascular stability and body temperature during laparoscopic procedures especially in children of low body weight. Type of study: Prospective observational study. Setting: ARO and COS, University Teaching Hospital Brno, Children Hospital. Patients: 40 children (26 boys, 14 girls) scheduled for laparoscopic surgery. Mean age 69.55 months (1 month to 18 years of age), mean body weight 23.93 kilograms; mean ASA grade 1.85. Method: Patients received routine oral premedication one hour before surgery (or were premedicated intramuscularly 30 mins prior to surgery). Anaesthesia was maintained with infusion of alfentanil (Rapifen) or fentanyl boluses with low dose isoflurane. Muscle relaxation was achieved by atracurium (Tracrium) or vecuronium (Norcuron). Patients were mechanically ventilated in volume control mode. Parameters of ventilation were adjusted according to continuously monitored CO2 in exhaled gas mixture (EtCO2). We recorded ventilator settings and lung mechanics characteristics (tidal volume, frequency, minute ventilation, airway pressures, compliance and EtCO2), cardiovascular parameters and body temperature. Blood saturation was monitored by pulse oximeter peripherally (SpO2) on both upper and lower parts of the body. We recorded the parameters after the induction to anaesthesia, after insufflation of peritoneal cavity and after desufflation. The results were compared using paired t-test. Results: The mean duration of the procedure was 57 minutes. Mean capnoperitoneum time was 44 minutes. Mean general anaesthesia duration was 85.2 minutes. After CO2 insufflation, minute ventilation was increased (RR 21.00/min vs 23.73/min, p<0.01). Tidal v olume (Vt) was decreased (8.93 ml/kg vs 8.68 ml/kg), but minute volume (MV) increased (3.96 l/min vs 4.26 l/min). Increase of airway pressure reached statistical significance: peak inspiratory pressure (PIP – 13.53 vs 17.33 cmH2O, p<0.01), mean airway pressure (Paw – 5.95 vs 7.02 cmH2O, p<0.05). After desufflation, all parameters return to starting points. In spite of an increase in minute ventilation, EtCO2 increased (4.81 vs 5.31 kPa, p<0.01), mild increase persists after desufflation (4.98 kPa, p<0.05). Respiratory system compliance decreases after insufflation (0.68 vs 0.53 ml/cmH2O/kg, p<0.01), after desufflation returns to normal values. Cardiovascular changes presented as increase in systolic blood presssure (sBP – 105 vs 118 mmHg, p<0.01) and diastolic blood pressure (dBP – 59 vs 73 mmHg, p<0.01). Mild decrease in heart rate did not decrease statistical significance (117 vs 112/min). SpO2 on both upper and lower limbs fluctuated between 98 and 100%. We did not observed changes between limbs. Body temperature after insufflation of cold CO2 decreased more in rectal compared to oral cavity. Those changes did not reach statistical significance. Both t emperatures rise after desufflation of capnoperitoneum. Conclusion: Capnoperitoneum significantly affects respiratory and cardiovascular profile of pediatric patients. Increase in minute ventilation was necessary to maintain normocapnia. We did not observe statistically significant drop in body temperature.

        Key words: capnoperitoneum – ventilatory parameters – lung mechanics – cardiovascular stability – body temperature – children