Measurement of intra-abdominal pressure

1. Clamp the drainage tube of the Foley (bladder) catheter.
2. Instill up to 60 cc sterile saline into the bladder via the aspiration port of the Foley catheter. Be certain the catheter is filled with fluid.
3. The pressure transducer can be held in place using an elastic strap as shown in the figure, or alternatively, it can be attached to an intravenous pole at the height of the midaxillary line. Attach a pressure transducer to an 18-gauge needle, and insert into the aspiration port. With some newer-style Foley catheters, a needle-less connection system can be used.
4. Zero the transducer at the level of the midaxillary line.
5. With the patient in the supine position, ensure that abdominal muscle contractions are absent, and measure the bladder pressure at end-expiration.