BACKGROUND: To evaluate tests for Veress needle tip placement intraperitoneally in the left hypochondrium for creating a pneumoperitoneum. METHODS: Needle tip placement tests were evaluated in one hundred patients using the left hypochondrium area. It was considered positive when: aspiration test (PA) -returned organic material; resistance test (PRes) - a low pressure was pushed on the syringe for the liquid infusion; recovery test (PRec) - no liquid was recovered after infusion; dripping test (PG) - drops drained quickly; test for initial intraperitoneal pressure (PPII) - levels were <= 8mmHg. Positive PA suggested bowel injury, while positive PRes, PRec, PG and PPII indicated that needle tip was adequately located in the peritoneal cavity. The Sensitivity ( SE) and Specificity ( SP ), as well as their predictive positive values (PPV) and predictive negative values ( PNV) of these tests were calculated using results correlation which were true-positives (a), false-positives (b), false-negatives (c) and true-negatives (d), accordingly to the formulas: SE =[a/ (a+c)]x100; SP =[d/(b+d)]x100; PPV=[a/(a+b)]x100; PNV=[d(c+d)]x100. RESULTS: If a positive PA had returned, SE and PPV did not fit, and SP=100% and PNV =100%. In the PRes, SE =0%, SP =100%, PPV = did not exist and PNV =90%. Both in the PRec and in the PG, results were for SE =50%, SP =100%, PPV =100% and PNV =94.7%. In the PPII test results were for SE, PPV and PNV =100%. CONCLUSION: Left hypochondrium negative PA guaranteed that bowel was not perforated; PRes test is a not accurate test for detection of the needle tip bad placement, however it accurately indicates its good positioning; PRec and the PG tests do not detect the adequate positioning, but they detect very well the inadequate positioning; PPII test shows with reliability both bad and good positioning of the needle, being the most trustworthy test among those studied.
Laparoscopy; Surgical procedures, operative; Pneumoperitoneum, artificial; Punctures
