Vascular air embolism occurring when air or gas enters into the vascular system, is a rare but potentially fatal event. It may occur in a variety of procedures and surgeries but is most often associated as an iatrogenic complication of central line catheter insertion. 

The physiologic effects that result depend on the volume of air that has entered the system, rate of air embolism, the type of gas (i.e., room air, carbon dioxide or nitrous oxide), and the position of the patient when the embolism occurs. Symptoms may range from asymptomatic to cardiovascular collapse and death. The emboli essentially cause a reduction in perfusion distal to the obstruction, but its additional damage results from an inflammatory response that the air bubble initiates. These inflammatory changes can result in pulmonary edema, bronchospasm, and increased airway resistance.
Conditions that can result in an air embolism include the following: crack in the central venous access device (CVAD); disconnection between catheter connections, that is, between the catheter and intravenous (IV) administration set or between the injection/access cap and an unclamped CVAD; presence of a persistent catheter tract following CVAD removal; deep inspiration during CVAD insertion or removal; and  inadvertent infusion of air in the IV administration set. 

Good and safe connection of IV tubing is critical to safe and effective IV therapy. Accidental disconnection of IV tubing connections during drug infusion is a potentially catastrophic yet avoidable event. Various retrospective clinical studies show that air embolism due to catheter disconnection has a mortality rate between 29 and 43%.In addition to the risk of developing an air embolism, IV disconnection and leakages increase the risk of infection and may result in significant blood loss, especially in neonates and infants. Medication discontinuation is another adverse event associated with IV disconnection.
Tubing leakages and disconnections can potentially be prevented, by thorough preparation, focusing on teamwork training, ensuring an ergonomic environment, and by making modifications to existing equipment. 

Misconnections or Luer connector misconnections are under-recognized but common and potentially dangerous events. Luer connector design allows direct or functional connection between unrelated delivery systems (e.g., vascular, enteral, respiratory, epidural, and intrathecal medical devices, components, and accessories). Multiple connections between medical devices and tubing are common in patient care and clinicians can mistakenly connect the wrong devices and deliver substances through the wrong route.

Prevention of these errors is dependent upon the clinician’s knowledge of the Luer connectors used and careful attention to all connections and tubing involved. These errors are further prevented by connector design – i.e color coding, tagging and especially by a physically incompatible design as outined in the ISO 80369-1:2018 standard that was published on 2018. This document provides the methodology to assess non-interconnectable characteristics of small-bore connectors based on their inherent design and dimensions in order to reduce the risk of misconnections between medical devices or between accessories for different applications, for example between enteral and non-enteral connectors.