Intraperitoneal pressure and volume of gas injected as effective parameters of the correct position of the Veress needle during creation of pneumoperitoneum.
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 x time +8.3 x 10(-5) x time(2) - 2.44 x 10(-7) x time(3); and VG = 0.813 + 0.0157 x 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 pneumoperitoneum, with a coefficient of determination of 0.8011 for IP and of 0.9604 for VG. The predicted values were as follows: 1 minute = 4.15; 2 minutes = 6.27; 3 minutes = 8.36; and 4 minutes = 10.10 for IP (mm Hg); and 1 minute = 1.12; 2 minutes = 2.07; 3 minutes = 3.01; and 4 minutes = 3.95 for VG (L).


CONCLUSIONS
Values of IP and VG at given time points during insufflation for creation of the pneumoperitoneum, using the Veress needle, can be effective parameters to determine whether the needle is correctly positioned in the peritoneal cavity.
Department of Surgery, Federal University of São Paulo, São Paulo, Brazil. jozevedo.dcir@epm.br
João L M C
JL
Azevedo
Otavio C
OC
Azevedo
Albino A
AA
Sorbello
Otavio M
OM
Becker
Otavio
O
Hypolito
Dalmer
D
Freire
Susana
S
Miyahira
Afonso
A
Guedes
Glicia C
GC
Azevedo
D000328:Adult; D000368:Aged; D002245:Carbon Dioxide / Q000008:administration & dosage*; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007327:Insufflation / Q000295:instrumentation*; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009339:Needles / Q000009:adverse effects*; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects / Q000295:instrumentation*; D011237:Predictive Value of Tests; D011312:Pressure; D015203:Reproducibility of Results
D002245:Carbon Dioxide