Ans. b (12) (Ref. Novak's Gynecology)INSUFFLATION NEEDLESVirtually all insufflation needles are modifications of the hollow needle designed by Veress. In cases uncomplicated by previous pelvic surgery, the preferred site for insertion is as close as possible to (or within) the umbilicus, where the abdominal wall is the thinnest.When pressed against tissue such as fascia or peritoneum, the spring-loaded blunt obturator is pushed back into the hollow needle, revealing its sharpened end. When the needle enters the peritoneal cavity, the obturator springs back into position, protecting the intraabdominal contents from injury. The handle of the hollow needle allows the attachment of a syringe or tubing for insufflation of the distention gas.1.A 3-mm incision adequate for the needle is made with a small scalpel, and the abdominal wall is elevated by gripping it in the midline below the umbilicusSafe insertion of the insufflation needle mandates that the instrument be maintained in a midline, sagittal plane while the operator directs the tip between the iliac vessels, anterior to the sacrum but inferior to the bifurcation of the aorta and the proximal aspect of the vena cava. Therefore, in women of average weight, the insufflation needle is directed at a 45-degree angle to the palienl'-S-SPLine. The needle's shaft is held by the tips of the fingers and steadily but purposefully guided into position only far enough to allow the tip's entry into the peritoneal cavity. The needle should never be forced.2.In instances in which known or suspected intraabdominal adhesions surround the umbilicus, alternative sites for insufflation needle insertion should be used.These include the pouch of Douglas, the fundus of the uterus, and the left upper quadrant, most often at the left costal margin. The left upper quadrant is preferred if there has been no previous surgery in this area. In most instances, both the insufflation needle, if used, and the primary cannula are inserted through the umbilicus.3.Before insufflation, the operator should try to detect whether the insufflation needle has been malpositioned in the omentum, mesentery, blood vessels, or hollow organs such as the stomach or bowel.Using a syringe attached to the insufflation needle, blood or gastrointestinal contents may be aspirated. This examination may be facilitated by injecting a small amount of saline into the syringe. If the needle is appropriately positioned, negative intraabdominal pressure is created by lifting the abdominal wall.4.Additional signs of proper placement may be sought after starting insufflation.The intraabdominal pressure reading should be low, reflecting only systemic resistance to the flow of CO2. Consequently, there should be little deviation from a baseline measurement, generally less than 10 mm Hg. The pressure varies with respiration and is slightly higher in obese patients. The earliest reassuring sign is the loss of liver "dullness" over the lateral aspect of the right costal margin.5.The amount of gas transmitted into the peritoneal cavity should depend on the measured intraperitoneal pressure, not the volume of gas inflated.Intraperitoneal volume capacity varies significantly between individuals. Many surgeons prefer to insufflate to 20 mm Hg for positioning of the cannulas. This level usually provides enough counterpressure against the peritoneum, facilitating trocar introduction and potentially reducing the chance of bowel or posterior abdominal wall and vessel trauma. After placement of the cannulas, the pressure should be dropped to 10 to 12 mm Hg, which essentially eliminates hypercardia or decreased venous return of blood to the heart.