A pressure bag is a device that is used to pressurize a bag filled with intravenous fluid for the purpose of regulating how quickly the fluid is dispensed to the patient. Sometimes also called pressure pumps, pressure bags can be used in numerous clinical settings. Companies that manufacture these bags usually sell several different versions, including disposable ones designed for use with a single patient, which are thrown away after one use. This reduces the amount of time and energy spent on sterilization and storage.
When a patient is set up with an intravenous line, the size of the intravenous catheter and the width of the line have an impact on how quickly fluids can be delivered. For a basic drip, a bag of fluids may be elevated on a pole above the patient, with gravity doing the work. Some fine tuning may be possible with clips. Using a pressure bag increases the rate of flow by pressurizing the bag and forcing the contents out more quickly.
Pressure bags are inflatable cuffs that can be manually inflated to a desired level of pressure. The rate of the drip can be controlled by increasing or decreasing the pressure. Emergency release valves allow care providers to relieve pressure if there is a problem. Historically, people improvised the bags by putting bags under the patient and using the patient's weight as a source of pressure, or by inflating a blood pressure cuff around the IV bag. The bag is a somewhat neater solution to the problem.
The major complication that can arise when using a pressure bag is the risk that the bag of fluid will burst. This will not injure the patient, although it can be startling, and if the bag is filled with something like a blood product or a hazardous medication, it can present a safety risk to health care providers in the room. Pressure relief valves are installed to limit the possibility of such events and care providers also use their judgment when inflating a pressure bag.
For very controlled delivery of intravenous fluids, a patient can be connected to an infusion pump. Infusion pumps can deliver very precise doses of medication over the period of time programmed into the device, which may be hours or days. They are especially useful when patients only need small amounts of a medication or when an intravenous drip needs to be tightly controlled to reduce the risk of giving the patient too much.