I describe here a new test. It is new in the sense that I have not written about it before, nor has anyone else. But I have been using it for years.
It is essential that the potential cavity of the peritoneum is converted into one filled with carbon dioxide, because unless one looks at anything from a distance, one cannot see anything well. Putting the tip of the telescope in contact with intraabdominopelvic structures without any distance between them is no good, because the focal length of the optics cannot be zero. Putting a gas into the peritoneal cavity is a blind procedure. If the gas passes into a wrong tissue plane, the procedure fails and can even be catastrophic. Correct placement of the tip of the pneumoperitoneum needle in the peritoneal cavity can be confirmed by a number of tests.
1. A drop of saline placed on the hub of the needle gets sucked into the needle (because of negative intraperitoneal pressure).
2. Saline injected through the needle cannot be reaspirated (because it gets lost in the peritoneal cavity).
3. Urine, stool, or blood cannot be aspirated through the needle (negative tests showing that the needle tip does not lie in bladder, bowel or a blood vessel).
4. Pressure of gas being insufflated through the needle shows a pressure of about 15 mm Hg (while it is thirty of more if the needle tip lies in the abdominal wall).
5. The abdomen distends uniformly (while it is localized if the needle tip lies in the abdominal wall).
Adequacy of the pneumoperitoneum is conventionally indicated by loss of liver dullness on abdominal percussion. The new test I describe here is to place flats of fingers of a hand on the abdominal wall and press it in gently. It rocks as if it is filled with jelly or fluid. It happens with ascites too. Gas and liquid are both fluids and share some features. This does not happen if the gas is not enough, and also when it is too much (when the abdominal wall is tense like skin of a percussion instrument).
I must mention a dangerous test performed by some flamboyant gynecologists, who percuss the distended abdominal wall with a hand. It produces a note as on percussion of a drum. It is possible because the abdomen is full of gas, there is a taut membrane over it which is percussed, and the patient is anesthetized so that she cannot object to such degrading treatment. This test is dangerous because the sharp increase in the intraabdominal pressure caused by the percussion may cause regurgitation of the stomach contents, which may be aspirated unless there is a cuffed endotracheal tube in place. I mention this test only to be condemned.
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