Volume status, VAE and CVC

Q: Which of the following tends to increase the risk of Venous Air Embolism (VAE) during central venous catheter (CVC) insertion? - Select one

A) Hypervolemia

B) Hypovolemia

Answer: B

Hypovolemia reduces the central venous pressure CVP, and this tends to have relatively more negative sucking power if a patient takes deep inspiration during CVC insertion.

VAE can occur at any phase of the catheter in the patient, including catheter insertion, while the catheter is in place or at catheter removal. The following are the common causes of VAE:

• Fracture or detachment of catheter connections 
• Failure to occlude the needle hub and/or catheter during insertion or removal (a very common overlook by many operators)
• Presence of a persistent catheter tract following the removal of CVC
• Deep inspiration during insertion or removal
• Hypovolemia
• Upright positioning of the patient - This reduces the CVP to below atmospheric pressure and places the patient at particular risk of rapidly entraining air into the venous circulation.

#procedures

References:

1. King MB, Harmon KR. Unusual forms of pulmonary embolism. Clin Chest Med 1994; 15:561.

2. Malik N, Claus PL, Illman JE, Kligerman SJ, Moynagh MR, Levin DL, Woodrum DA, Arani A, Arunachalam SP, Araoz PA. Air embolism: diagnosis and management. Future Cardiol. 2017 Jul;13(4):365-378. doi: 10.2217/fca-2017-0015. Epub 2017 Jun 23. PMID: 28644058.

3. Wong SS, Kwaan HC, Ing TS. Venous air embolism related to the use of central catheters revisited: with emphasis on dialysis catheters. Clin Kidney J. 2017 Dec;10(6):797-803. doi: 10.1093/ckj/sfx064. Epub 2017 Jul 28. PMID: 29225809; PMCID: PMC5716215.