Intraperitoneal pressure and volume of gas injected as effective parameters of the correct position of the Veress needle during creation of pneumoperitoneum.

Abstract Objective: The aim of this work was to establish reliable parameters of the correct position of the Veress needle in the peritoneal cavity during creation of pneumoperitoneum. Methods: The Veress needle was inserted into the peritoneal cavity of 100 selected patients, and a carbon-dioxide flow rate of 1.2 L/min and a maximum pressure of 12 mm Hg were established. Intraperitoneal pressure (IP) and the volume of gas injected (VG) were recorded at the beginning of insufflation and at every 20 seconds. Correlations were established for pressure and volume in function of time. Values of IP and VG were predicted at 1, 2, 3, and 4 minutes of insufflation, by applying the following formulas: IP = 2.3083 + 0.0266 × time +8.3 × 10−5 × time2 − 2.44 × 10−7 × time3; and VG = 0.813 + 0.0157 × time. Results: A strong correlation was observed between IP and preestablished time points during creation of the pneumoperitoneum, as well as between VG and preestablished time points during creation of the pneumoperiton...