RESUMO
INTRODUCTION: The objectives were to study the changes in the mechanics of respiration in children undergoing surgery depending on the value of intra-abdominal pressure (IAP) during laparoscopic procedures, and to compare the effects of different mechanical ventilation modes - pressure controlled (PCV) and volume controlled (VCV) ventilation - on the mechanics of respiration considering carboxyperitoneum conditions (CP). AIM: To study the changes in the mechanics of respiration in operated children depending on the value of intra-abdominal pressure during laparoscopic procedures. MATERIAL AND METHODS: Fifty-two children aged 1-12 years undergoing laparoscopic surgery on inguinal hernias were randomly allocated to receive mechanical ventilation using either VCV (n = 24) or PCV (n = 28) mode. Respiratory mechanics were measured before application of carboxyperitoneum (initial data) and after the gas had been pumped into the abdominal cavity, at the following intra-abdominal pressure values: 6 mm Hg, 8 mm Hg, 10 mm Hg, 12 mm Hg, 14 mm Hg. RESULTS: Elevation of intra-abdominal pressure due to carboxyperitoneum conditions had a negative effect on the mechanics of respiration. Changes in the respiratory mechanics were restrictive in nature in both groups. The patients who were receiving pressure controlled ventilation showed a decrease in tidal volume, exhaled minute volume, and dynamic lung compliance, which affected the gas exchange at intra-abdominal pressure values ≥ 12 mm Hg. Patients who were receiving volume controlled ventilation showed an increase in peak inspiratory pressure and mean airway pressure and a decrease in dynamic lung compliance in response to higher intra-abdominal pressure. A significant increase of concentration of exhaled carbon dioxide (etCO2) was registered at IAP ≥ 12 mm Hg. CONCLUSIONS: Application of carboxyperitoneum causes increased intra-abdominal pressure and restrictive disorders in respiratory mechanics. Intra-abdominal pressure readings within 8-12 mm Hg allow laparoscopic procedures to be performed without significant gas exchange disorders in children older than 1 year.
