Study objectives: Since most gynecologists use the Veres/trocar entry, and because the Veres intraperitoneal (VIP) pressure appears to be the most reliable indicator of correct Veres needle placement, the objective of this study was to determine the effect of height, weight, body mass index (BMI), parity, and age on the initial Veres intraperitoneal CO2 insufflation pressure during laparoscopic access in women.
Design: Prospective observational cohort study (Canadian Task Force classification II-1).
Setting: University affiliated teaching hospital.
Patients: We prospectively collected data on 356 women undergoing laparoscopy for a variety of indications by the senior author (G.A.V.). The median and (range) for height, weight, BMI, parity, and age were 1.64 m (1.45-1.85 m), 65 kg (40-120 kg), 24.3 kg/m2 (16-47 kg/m2), 1 (0-5) and 34 years (18-87 yrs), respectively.
Intervention: Under general endotracheal anesthesia including muscle relaxants and with the patient in appropriate stirrups in the horizontal position, a nondisposable Veres needle was inserted at the umbilicus or left upper quadrant (Palmer's point) with CO2 flowing at 1 L/min. The initial Veres intraperitoneal insufflation pressure was recorded once the Veres needle was believed to be in the peritoneal cavity.
Measurements and main results: The mode and the median VIP pressure was 4 mm Hg with a range of 2 to 10 mm Hg. With multivariate analysis, the VIP pressure correlated positively with the weight (r = 0.518, p <.001) and BMI (r = 0.545, p <.001) and negatively with the parity (r = -0.179, p <.001) of women. The correlation of the VIP pressure with height and age was r = 0.029 (p = .591) and r = -0.044 (p = .411), respectively.
Conclusion: A VIP pressure < or =10 mm Hg indicates intraperitoneal placement of the Veres needle. The VIP pressure correlates positively with the weight and BMI and negatively with the parity of women. There is no correlation of the VIP pressure with women's height and age.