A compilation of journals, case studies and articles about Air Embolism.
Sowell MW, Lovelady CL, Brogdon BG, Wecht CH. Infant death due to air embolism from peripheral venous infusion. J Forensic Sci. 2007 Jan;52(1):183-8.
Swartz N, Eisenkraft JB. Probable venous air embolism during epidural placement in an infant. Anesth Analg 1993;76:1136–8.
Chang AC, Wells W. Shunt lesions. In: Chung AC, Hanley FL, Wernovsky G, Wassell DL, editors. Pediatric cardiac intensive care. Philadelphia: Saunders, 2005:207–8.
Diagnosis & Treatment
Mirski MA, Lele AV, Fitzsimmons L, Toung TJ. Diagnosis and treatment of vascular air embolism. Anesthesiology. 2007 Jan;106(1):164-77. Review.
Shaikh N, Ummunisa F. Acute management of vascular air embolism. Journal of Emergencies, Trauma and Shock. 2009;2(3):180-185.doi:10.4103/0974-2700.55330.
General Review Articles
Muth CM, Shank ES. Gas embolism. N Engl J Med. 2000 Feb 17;342(7):476-82. Review.
von Jürgensonn S. Prevention and management of air in an IV infusion system. Br J Nurs. 2010 May 27-Jun 9;19(10):S28-30.
O'Quin RJ, Lakshminarayan S. Venous air embolism. Arch Intern Med. 1982 Nov;142(12):2173-6.
Laskey AL, Dyer C, Tobias JD. Venous air embolism during home infusion therapy. Pediatrics. 2002 Jan;109(1):E15.
Orebaugh SL. Venous air embolism: clinical and experimental considerations. Crit Care Med. 1992 Aug;20(8):1169-77. Review.
Hartveit F, Lystad H, Minken A. The pathology of venous air embolism. Br J Exp Pathol. 1968 Feb;49(1):81-6.
Oyama Y, Spencer MP. Cardiopulmonary effects of intravenous gas embolism; with special reference to fate of intravascular gas bubbles. Jpn Circ J. 1971 Dec;35(12):1541-9.
Wong B, Zimmerman D, Reintjes F, Courtney M, Klarenbach S, Dowling G, Pauly RP. Procedure-related serious adverse events among home hemodialysis patients: a quality assurance perspective. Am J Kidney Dis. 2014 Feb;63(2):251-8. doi: 10.1053/j.ajkd.2013.07.009. Epub 2013 Aug 30. Review.
Bessereau J, Genotelle N, Chabbaut C, Huon A, Tabah A, Aboab J, Chevret S, Annane D. Long-term outcome of iatrogenic gas embolism. Intensive Care Med. 2010 Jul;36(7):1180-7. doi: 10.1007/s00134-010-1821-9. Epub 2010 Mar 11
Marchand P, Van Hasselt, Luntz CH. Massive venous air embolism. S Afr Med J. 1964 Mar 28;38:202-8.
Durant TM, Long J, Oppenheimer MJ. Pulmonary (venous) air embolism. Am Heart J. 1947 Mar;33(3):269-81
Palmon SC, Moore LE, Lundberg J, Toung T. Venous air embolism: a review. J Clin Anesth. 1997 May;9(3):251-7. Review.
Laidlow, Kate. Air Embolism ? : Don’t worry it was just a bubble…. IVNNZ Newsletter. 2011.
Bhananker SM, Liau DW, Kooner PK, Posner KL, Caplan RA, Domino KB. Liability related to peripheral venous and arterial catheterization: a closed claims analysis. Anesth Analg. 2009 Jul;109(1):124-9. doi: 10.1213/ane.0b013e31818f87c8.
Domino KB, Bowdle TA, Posner KL, Spitellie PH, Lee LA, Cheney FW. Injuries and liability related to central vascular catheters: a closed claims analysis. Anesthesiology. 2004 Jun;100(6):1411-8. Review.
Barak, Michal, and Yeshayahu Katz. "Microbubbles: pathophysiology and clinical implications." CHEST Journal 128.4 (2005): 2918-2932.
Barak M, Nakhoul F, Katz Y. Pathophysiology and clinical implications of microbubbles during hemodialysis. Semin Dial. 2008 May-Jun; 21(3):232-8. doi: 10.1111/j.1525-139X.2008.00424.x. Review.
Klinger AL, Pichette B, Sobolewski P, Eckmann DM. Mechanotransductional Basis of Endothelial Cell Response to Intravascular Bubbles. Integrative biology : quantitative biosciences from nano to macro. 2011;3(10):1033-1042. doi:10.1039/c1ib00017a.
Yu X, Xu J, Huang G, et al. Bubble-Induced Endothelial Microparticles Promote Endothelial Dysfunction. Bader M, ed. PLoS ONE. 2017;12(1):e0168881. doi:10.1371/journal.pone.0168881.
Warmers, Pumps & Filters
Woon S, Talke P. Amount of air infused to patient increases as fluid flow rates decrease when using the Hotline HL-90 fluid warmer. J Clin Monit Comput. 1999 May;15(3-4):149-52.
Stevenson GW, Tobin M, Hall SC. Fluid warmer as a potential source of air bubble emboli. Anesth Analg. 1995 May; 80(5):1061.
Destiny Chau, D, Gish,B, Tzanetos, D, Zhang, C. A dangerous side of In-Line IV filters when used for vasoactive infusions in infants. J Anesth Safety Patient Foundation. 2013; 28(2).
Wolin, J, Vasdev, G. Potential for air embolism using Hotline™ model HL90 fluid warmer. J Clin. Anesth. 1996; 8(1):81-82.
Breen, P, Hong, A. Beware of Air in the Blood Pump. Anesth Analg. 2000; 91(4):1038.
Varga C, Luria I, Gravenstein N. Intravenous Air: The Partially Invisible Phenomenon. Anesth Analg. 2016 Nov;123(5):1149-1155. PubMed PMID: 27749346.
Haddad, I., Doucet, P., Lobozzo, J., Vadhera, A. Volume of Air Generated from HotlineⓇ Warmer – Plenty to Cause Serious Injury/Morbidity in Pediatrics. ClearLine MD. 2016.
Sviri S, Woods WP, van Heerden PV. Air embolism--a case series and review. Crit Care Resusc. 2004 Dec;6(4):271-6.
Williamson JA, Webb RK, Russell WJ, Runciman WB. The Australian Incident Monitoring Study. Air embolism--an analysis of 2000 incident reports. Anaesth Intensive Care. 1993 Oct;21(5):638-41.
Cereda C, Staedler C, Moschovitis G, Caronni F, Bassetti CL, Azzola A. 'Bubbles in the brain': systemic air embolism syndrome from an atrial-oesophageal fistula. Emerg Med J. 2011 May;28(5):455. doi: 10.1136/emj.2010.093195.
Tommasino C, Rizzardi R, Beretta L, Venturino M, Piccoli S. Cerebral ischemia after venous air embolism in the absence of intracardiac defects. J Neurosurg Anesthesiol. 1996 Jan;8(1):30-4.
Fibel KH, Barnes RP, Kinderknecht JJ. Pressurized Intravenous Fluid Administration in the Professional Football Player: A Unique Setting for Venous Air Embolism. Clin J Sport Med. 2015 Jul;25(4):e67-9. Doi: 10.1097/JSM.0000000000000150.
20 April 2017
By: Gerard J. Myers, RT, CCP Emeritus, Eastern Perfusion International
Going back to the statement, that it would take a lot of air to cause you any harm makes you wonder how much air it would actually take to create a sudden, life threatening problem after the air went into the bloodstream. It has been reported that a slow infusion of air (> 0.36 mls/Kg/minute) can have a negative impact on the lung circulation after leaving the right side of the heart and entering the blood flow to the lungs (pulmonary circulation) … thereafter leading to a state of massive blood pressure drop. Single large injections of air into a vein (between 25 mls and 75 mls) can result in rapid breathing, heart rhythm changes and a decrease in blood pressure, likely due to an airlock in the right side of the heart. In addition, this air can cause injury as a result of activating complement and other inflammatory mediators which can then lead to fluid leakage in the lungs and the possibility of pulmonary edema.
In healthcare, discussions around venous air generally circulate around two areas of concern. One is that it would take large volumes of air to cause death and that small volumes of air are therefore/probably inconsequential. The second area of discussion revolves around the fact that microbubbles are frequently found in intravenous (IV) lines and can be bothersome and difficult to remove by the clinician.
But what should concern us all is the fact that there is technology available to remove all the air (small microbubbles and large volumes) from an intravenous line. This technology is in the form of intravenous line air filters. The smallest of these filters used in IV lines are 0.2 microns in size and not only remove microbubbles from the fluids infused, but precipitates, fragments of glass, plastic and rubber. Since most bacteria (including gram negative bacteria) range between 1.0 and 5.0 microns in size, these IV filters can be very useful in preventing bacterial contaminants from entering the bloodstream during intravenous fluid therapy. As long as these intravenous filters are maintained at the same level as the patient’s heart, they are very effective at their job.
Unfortunately, IV filters are only used in some neonatal and pediatric cases where they suspect or know of a PFO. You might ask why they are not used in adults or all cases where IV fluids are used, and my answer to you would be … that is a very good question. Perhaps it is based on the filters added cost to healthcare or their availability in your particular country. Perhaps it is based on the fact that they require some deep change in a clinician’s long held practice/belief, or even a lack of knowledge about their benefits within the medical community. In my humble opinion, they should be a routine part of intravenous fluid therapy because they have the ability to reduce morbidity and mortality associated with IV infusions and IV micro-air. The culture of “a little air won’t hurt you” is as outdated as the Model T Ford, and it is time to stop perpetuating this misguided belief on future generations of health care workers … and especially patients with IV lines in place.
So the question now comes back to you … that person who is noticing that large air bubble slowly coming down the intravenous line. In the absence of an IV filter, should you accept the word of the person who tells you not to worry about that air in your IV line and just smile as you watch as the air bubble slowly enter your arm … or should you pinch that line and insist the air be removed from the IV line before it enters your bloodstream? Well I guess the only way you can respond to this question really comes down to you … and how lucky do you feel on that given day?
Information, data and references for this post came from “Gaseous Microemboli During Cardiopulmonary Bypass,” published by Sorin Group, Mirandola, Italy in 2011 (revised in 2017) by Gerard J. Myers.
© 2017 Gerard Myers
19 April 2017
By: Gerard J. Myers, RT, CCP Emeritus, Eastern Perfusion International
At birth, we are all born with an opening in the atrial wall of our heart that separates the right side of our heart and the left side of our heart. This opening is called a Foramen Ovale, and usually closes with our first few breaths at birth, sending venous blood to the lungs and arterial blood to the brain and the rest of the body. Some Foramen Ovale defects do not close at birth and are thereafter called a Patent Foramen Ovale (PFO) which often can be detected through auscultation by finding heart murmurs and subsequent follow up radiology exams. This PFO is estimated to still be present in about 10% to 35% of adults (that’s approximately 1 in every 5-6 people) and has been reported to be an important risk factor for strokes, cerebrovascular accidents and transient ischemic attacks (TIA’s). Some people know they have a PFO but most do not until the doctor detects it. People generally function well and go through life with a PFO until they get diagnosed on routine examination or develop symptoms.
Even in the absence of a PFO, microbubbles have the potential to pass from the venous circulation into the left side of the heart through shunts that exist in the lung, called Intrapulmonary Arteriovenous Anastomoses (IPAVA), which are just small blood vessels that do not contact the air sacs in our lungs and therefore allow venous blood (and emboli) to pass directly into the left side of the heart. These IPAVA shunts are known to exist in approximately 30% of resting adults, and have the potential to increase in number in all adults during exercise. Even a very small percentage of people (approximately 30/100,00) have small openings in the ventricular walls of their hearts (sometimes referred to as probe patent openings) that can allow blood movement between these chambers, but may not cause any problems for the person.
Bubbles that enter your veins and move into the right atrium of your heart are called a Venous Air Emboli (VAE), regardless of size of these bubbles. About 20-25% of the general population (about 1 in every 4-5 people) has the potential for venous air bubbles to cross over to the left side of the heart through the PFO, and > 30% in those people with patent IPAVA shunts. When air bubbles do this (pass from the right side of the heart into the left side of the heart), it is referred to as a Paradoxical Air Embolism (PAE). Small amounts of air that do get into the left side of the heart from a PAE, can then be sent to the brain as the heart ejects blood from the left ventricle through the aortic valve.
The problem for the health care provider and especially for the patient with an intravenous line in place, is that either of these individuals have any indication or any warning signs that the patient may have a PFO or any degree of IPAVA shunts.
To determine the presence a right to left shunt (specifically a PFO) some cardiology clinics will perform a test called the ‘bubble study’. This is a test where a fixed amount of saline solution (usually 9.0 ml) is mixed with a fixed amount of air (usually 1.0 ml) and shaken in the syringes to create a large amount of small microbubbles. This microbubble solution is then injected into a vein while ultrasound is used to see if any of the microbubbles are transmitted to the left side of the heart through an opening in the heart wall (PFO). Theoretically, if a PFO exists, paradoxical air will be detected on the left side of the heart. But in the absence of a PFO, all of the microemboli should stay on the right side of the heart and transit through the lungs with the venous blood to be subsequently (and theoretically) removed in the air sacs of the lungs. However, through the use of ultrasound devices placed on both sides of the brain, investigators found that cerebrovascular complications such as trans-ischemic attacks (TIA) and strokes can occur in patients who do have some paradoxical air on the left side of the heart due to a PFO or IPAVA shunts.
One intraoperative study investigating 21 adult neurosurgical patients for the incidence of PAE as it relates to air bubbles entering the bloodstream during routine intravenous fluid injections (through an IV line), found that air bubbles were detected in the right side of the heart in all of the patients in the study. But more importantly, 3 of those 21 patients (14.3%) were found to have air bubbles that passed through the atrial wall and lodged in the left side of the heart as a paradoxical air embolism … which remained present even after the bubbles in the right side of the heart dissipated. All of the patients were in a sitting position and no one in the study was known to have the presence of a PFO or probe patent opening.
© 2017 Gerard Myers
18 April 2017
By: Gerard J. Myers, RT, CCP Emeritus, Eastern Perfusion International
Part 1 of 3
When was the last time you, or one of your loved ones, was in a hospital bed with an intravenous line attached to your arm and a bag of intravenous fluid hanging from an IV pole beside you? Perhaps when the bag of fluid began to empty, a health care worker entered the room to hang another bag of the lifesaving liquid, or maybe just attach a smaller bag of medication to run into you intravenous line. As she/he changed the bag and adjusted the drips on your IV line you sat silently in deep thought about when you were getting out of the hospital or what you had to do that day. But out of the corner of your eye you noticed a large bubble of air slowly advancing down your IV line toward your arm. You raised the alarm about the bubble to the clinician and were told that ‘there is nothing to worry about, because a little bit of air will never hurt anyone’. This explanation is usually followed by another short explanation about how it would take a massive amount of air to cause you any harm, and that there is nothing to worry about with those little bits of air.
Unfortunately, this scenario is repeated thousands of times by health care workers who still consider venous air bubbles as inconsequential, and subsequently spend their careers disregarding small amounts of air bubbles entering the venous circulation through an intravenous line. In fact, it is almost impossible to estimate how many times air bubbles enter a patient’s blood stream through intravenous lines, in every healthcare setting. These bubbles are often referred as iatrogenic air (coming from the activity of a health care provider). No harm is ever intended, assumed or even imagined, but it is often just a part of the clinician’s training, their routine practice of maintaining an intravenous infusion, and their misinformation around the hazards of air bubbles entering the venous circulation.
The reality is … small amounts of air bubbles entering a person’s blood stream can have adverse consequences and can be harmful. What is interesting is the fact that there is absolutely no reason why any amount of air or air bubbles should be allowed to pass through an intravenous line in any patient. Every clinical protocol for setting up and maintaining an intravenous line, stresses the importance of making sure all of the air is removed from that line before it is attached to a patient’s circulatory system. All air bubbles are foreign to our circulation and the majority can easily be removed from an intravenous line before entering the patient’s circulation. But more importantly, air bubbles have the potential to cause harm and are not in the best interest of the patient … let me explain why.
First of all, regardless of the size of the bubble or its point of entry into our arterial or venous blood streams, bubbles or any particles entering our bloodstream are alien to our circulation and our physiology. Because of this, once a bubble enters the bloodstream, it is immediately attacked and treated like any other foreign substance that enters our body’s natural defense mechanisms. The bubbles are immediately coated by platelets, white blood cells and other proteins as they travel toward the right side of the heart. During their course through the bloodstream, they can damage or degrade the blood vessels delicate lining (called endothelial glycocalyx and its underlying endothelial cells) resulting in endothelial cell edema, inflammation, localized platelet and white cell activation and even blockages in the tiny pulmonary capillary vessels, much in the same manner that a solid or fat embolus would do. Over time, it is believed these bubbles will gradually dissolve in the blood, but not before damaging this endothelial glycocalyx layer as they slip/slide through the microcirculation.
The normal size of our capillaries (microcirculation) is somewhere between 4-9 microns in diameter, but the bubbles trying to pass through these capillaries can be hundreds or thousands of microns larger. If those bubbles break up and enter the arterial blood going to the brain, they have the ability to cause neurocognitive dysfunction (memory loss, emotional upset, etc) or stroke.
© 2017 Gerard Myers
10 April 2017
A new study found a dangerous amount of air is emitted by fluid warmers - enough to cause serious clinical complications in pediatrics.
15 March 2017
March 12 - 18 is Patient Safety Awareness Week, an initiative of the National Patient Safety Foundation that encourages everyone to Stand United for Patient Safety to reduce harm in patient care. #WEAREALLPATIENTS
The danger of air masses in IV lines is an important patient safety issue - and one that can be avoided. Air masses in IV lines can be fatal and may cause serious clinical complications, extended hospital stays, and additional costs. ClearLine IV is the only FDA-cleared, CE-certified product that detects and removes air in IV fluid lines continuously and automatically. Help spread awareness about the issue of air in IV lines and the importance of protecting patients against the dangerous infusion of air.
© 2017 ClearLine MD
08 March 2017
Pumps are well known to have issues dealing with air in IV lines. Within the past 10 years, 2,549,871 pumps were included in recalls due to air-related accidents or incidents according to the FDA’s Maude database for adverse events.
The 2.5 million pumps were recalled due to air-related issues including faulty air-in-line sensors, failure to detect air in lines while using specific medications, false air-in-line alarms, wrong air sensor calibrations, failure to meet air-in-line specifications, defects in tubing, and failure to maintain pump accuracy for detecting air bolus. All of these could potentially lead to dangerous levels of air being delivered to patients.
In addition to potentially entraining air, the FDA warns that “the interruption of therapy can lead to serious adverse health consequences or death.” Health professionals must be vigilant in ensuring the lines are clear of air to avoid the risk of air entering the patient line.
Recalled models include the Alaris Pump Module, Model No. 8100 and AIL sensor kits, Hospira brand Symbiq Two-Channel Infuser, Triton Infusion Pump, Sigma Spectrum Infusion Pump, Baxter Colleague CX Infusion Pump, Baxter Flo-Gard 6301 Dual Channel Volumetric Infusion Pump, Baxter Colleague 3 and 3 CX Infusion Pumps, Curlin Ambulatory Infusion Pump System and Administration set, and Infinity Enteralite Ambulatory Feeding Pumps.
The Maude database houses medical device reports submitted to the FDA by mandatory reporters when marketed devices may have caused or contributed to a death or serious injury or has malfunctioned in a way that would likely cause or contribute to a death or serious injury. The FDA encourages health professionals to report adverse hospital events online at: www.fda.gov/MedWatch/report.
Note: graph only includes hardware
13 February 2017
The FDA just announced a recall of nearly 350,000 Alaris Syringe Pumps for faulty air detection sensors. Of great concern, the faulty sensors may cause the pump to stop therapy infusion to the patient. Healthcare professionals may have to clear the alarm and restart the infusion. The FDA recall warns that “interruption of infusion could lead to serious adverse health consequences or death.”
This recall yet again underscores the challenges pumps have detecting air masses in IV lines and reliance on clinicians to intercept and manually remove air from IV lines.
The FDA encourages health professionals to report adverse hospital events online at: www.fda.gov/MedWatch/report. Additional information and a copy of the recall is available here.
CareFusion recall included Alaris Syringe Pump model no. 8100 and air-In-line sensor kits (P/N 147083-102 and 49000221) manufactured and distributed between 2011 and 2015.
© 2017 ClearLine MD