Vascular Air Embolism: Explaining Tiny Bubbles to Patients

It happens almost every shift — I hang an IV infusion, and no matter how carefully the tubing is primed, at least one tiny bubble passes the pump’s electronic air detector, and floats its way towards my patient. The patient reacts with a tense expression, visually following the tiny bubble’s journey to the IV site. “Is it okay to have an air bubble in the tubing?”

Tiny Bubbles by jparadisi

Tiny Bubbles by jparadisi

I know they are thinking of the TV medical dramas of the 70s and 80s, shows like Mannix, or Quincy, in which a murderer sneaks into a hospital room and carefully injects the tiniest of bubbles into the IV tubing of the sleeping victim, who suddenly codes while the murderer, dressed in scrubs, slinks away unnoticed.

The question remains, however: How much air is too much in venous access? The answer is — the amount that makes a patient symptomatic.

Minor cases of air embolism are common and cause minimal or no symptoms. Severe cases are characterized by hemodynamic collapse and/or acute insufficiency of certain organs, including the lungs, brain, and spinal cord.¹

This is not new information for experienced nurses, but it is for most patients. Nearly all VAE (venous air embolism) occurs in conjunction with venous access devices. In fact,

60-90 percent are caused by “fractures or detachment of catheter connections.”¹

Other factors include:

  • Failure to occlude the needle hub and catheter while inserting or discontinuing an IV site
  • Self-sealing valve failure
  • A tract that remains after central venous catheter removal
  • Positioning the patient upright during central venous catheter removal

Oncology nurses use venous access devices regularly. VAE prevention includes:

  • Priming IV infusion tubing and needle hubs
  • Testing nurse inserted catheters for patency before insertion
  • Securing all IV and central line connectors
  • Instructing patients to perform a Valsalva Maneuver during central line removal
  • Placing patients in supine position during central venous catheter removal
  • Covering the removal sites of central venous catheters with an occlusive dressing

Symptoms of air embolism include:

  • Dyspnea
  • Chest pain
  • Sense of impending doom
  • Lightheadedness
  • Tachypnea
  • Tachycardia
  • Hypotension
  • Wheezing
  • Change in mental status

Severe air embolism is a medical emergency. If you suspect air embolus:

  • Call the Rapid Response Team or Code Team
  • Place the patient in left decubitus position
  • Begin supplemental O2

Prevention is the best treatment for an air embolus. All oncology nurses should demonstrate infusion therapy competency in the patient care setting.

Have you witnessed a patient experiencing VAE? What recommendations for preventing VAE would you add? What policies have your workplace initiated?

References:

  1. Air Embolism, 2013 UpToDate Authors: Liza C O’Dowd, MD, Mark A Kelley, MD, Section Editor: Jess Mandel, MD, Deputy Geraldine Finlay, MD