Infusion Pump Air Detection
FAQ [Health Devices Apr-May 1998;27(4-5):174-5]
What are the appropriate air-detection
volumes for infusion pump air-in-line sensors?
Air-in-line sensors, which are found in
general-purpose infusion pumps, can typically detect minimum air volumes between
0.05 and 0.2 mL. This range is several orders of magnitude smaller than the
volume of air thought to be capable of causing a lethal embolus if infused into
a patient—common estimates of the lethal volume vary between 10 and 500
mL. Peripheral venous emboli, such as those that are possible during traditional
peripheral infusions, usually result from air volumes between 100 and 500 mL. On
the other hand, central venous emboli, such as those that can occur during
infusion through a peripherally inserted central catheter (PICC), can be
produced even by the lower air volumes in the range thought to be lethal.
We are not aware of any reports of fatal venous air embolism that occurred during the use of pumps having functional air-in-line detectors. This suggests that any detector with minimum volumes within the 0.05 to 0.2 mL range provides sufficient protection from an embolism.
Some pumps allow the air-detection volume to be selected from a variety of settings. When these pumps are used, the smallest volume should be selected, especially for neonatal applications. However, this recommendation does not apply to pumps that can be set to detection limits below 0.05 mL, since such limits are likely to cause frequent nuisance alarms. We do not believe that such settings need to be used. If a facility feels a strong need to prevent the infusion of air volumes less than 0.05 mL, an air-eliminating filter can be used downstream from the pump. And some pump administration sets have air traps that will collect typical air volumes produced during infusion, which can further reduce air-in-line risks.
Infusion Pumps, General-Purpose [13-215]