Background: To analyze the effects of transitory, high intra-abdominal pressure on clinical, hemodynamic, blood gas and metabolic parameters.

Methods: Sixty-seven laparoscopic patients were divided into groups P12 (n = 30, maximum intra-abdominal pressure of 12 mmHg) and P20 (n = 37, maximum intra-abdominal pressure of 20 mmHg). Through radial artery cannulation, mean arterial pressure (MAP) was assessed and blood gas analysis – pH, arterial oxygen tension (PaO2), arterial carbon dioxide tension (PaCO2), bicarbonate (HCO3) and base excess (BE) – was performed. These parameters were evaluated in both groups at time point zero, before CO2 insufflation; at time point one (TP1), when intra-abdominal pressure of 12 mmHg was reached in both groups; at time point two (TP2), 5 minutes after reaching intra-abdominal pressure of 12 mmHg in group P12 and of 20 mmHg in group P20; and at time point three (TP3), 10 minutes after reaching intra-abdominal pressure of 12 mmHg in group P12 and 10 minutes after TP1 in group P20, when intra-abdominal pressure decreased from 20 mmHg to 12 mmHg. Values out of the normal range or the occurrence of atypical phenomena suggestive of organic disease indicated clinical changes.

Results: Significant variations in MAP, pH, HCO3 and BE were observed in group P20; these changes, however, were within normal limits. Clinical changes were also within normal limits, and no pathological phenomena were observed.

Conclusions: Brief, intra-abdominal hypertension for the insertion first trocar insertion causes variations in MAP, pH, HCO3 and BE without adverse effects, and it may protect from iatrogenic injury
