To the Editor

The safe administration of intravenous (M fluids requires that the infusion apparatus be used correctly. I recently have cared for several patients in which the plastic IV fluid containers had been placed under the patients’ heads in the horizontal position rather than hanging in the vertical position above heart level. In each case, it was noticed that air had displaced the fluid within the drip chamber and had entered the outlet tubing. Fortunately, none of the air reached these patients’ veins. I measured the volume of air remaining in one container with a needle and syringe. The volume of gas recovered was 59 ml.

I contacted a representative of the manufacturer who stated that air within the fluid container is a normal by-product of the manufacturing and filling processes. The potential clinical significance of this finding prompted me to evaluate the presence of air within other plastic IV fluid containers utilized in our hospital. On inspection it appeared that all the IV fluid containers in the surgical suite contained air. Therefore, the volume of air was measured in the IV containers (PLI46) of nine additional patients, selected at random. The mean volume of air was 60.2 ml with a range of 56 to 68 ml.

The accidental administration of IV air is an infrequent clinical occurrence, but tiny air bubbles can enter the IV tubing when drugs are injected or when fluid containers are attached. These events are usually without consequence, but complications with serious morbidity or even mortality can occur. (1) An IV dose of 60 ml air if administered slowly would probably not produce serious consequences in a normal-sized healthy adult. However, the presence of compromised cardio-respiratory function, a relatively rapid rate of air administration, and the concomitant use of nitrous oxide (2) could contribute to increased morbidity and mortality. Furthermore, the presence of a patent foramen ovale could lead to arterial (paradoxical) air embolism. (3)

To avoid the potential complication of venous air embolism during fluid administration, all containers should be mounted in a vertical position above the level of the right heart. Patient areas in the pre-, intra-, and post-surgical areas (including transport) should have appropriate container supports. Health care personnel who administer IV fluids or blood, utilizing external pressurized systems, should be aware that intra-container air may gain access to IV tubing with subsequent delivery to the patient. Furthermore, the addition of air to any fluid container for the purpose of internal pressurization is extremely dangerous and should be avoided. Hospitals should address these problems with written policies.

Edwin S. Munson, M.D. Cincinnati, OH

References

1. Yeakel AE. Lethal air embolism from plastic blood storage container. JAMA 204:267-69,1968.
2. Munson ES, Merrick HC. Effect of nitrous oxide on venous embolism. Anesthesiology 27:783-87,1972.
3. Gronert GA, Messick JM, Cucciara RF, et al. Paradoxical air embolism from a patent foramen ovale. Anesthesiology 50:54849,1979.