WoundReference improves clinical decisions
 Choose the role that best describes you
We have a patient who has been receiving HBO in a monoplace chamber. The wound was not showing progress, so Podiatrist took into surgery and debrided the involved bone and resected the cuboid. She placed an antibiotic bone spacer and external fixator. I reached out to the manufacturer to determine what type of metals the fixator is made of. At first, I was verbally told they were made of titanium. Once I rec'd the General Product Information form, it states "The fixators are made of several materials: aluminum, stainless steel, and composite materials". I requested if the manufacturer could tell me what "composite materials" include. He was not sure, but is going to research. In the Go-No-Go list, in the "Do Not Use in a Monoplace Chamber", under metal, it lists external fixation devices, and lists the hazard as acrylic damage/energy. Can you please give input on whether it is safe to put someone in a monoplace chamber with an external fixator, if the fixator is wrapped with a 100% cotton towel?
Feb 24, 2022 by Barbara Keller, RN, MSN, CWS
5 replies
Jeff Mize
RRT, CHT, UHMSADS
Barb, Thanks for your questions.
Due to the growing use of titanium in consumer products, an increasing number of patients may unknowingly bring titanium items in the form of eyeglasses inside the hyperbaric chamber. If these titanium items are only exposed to air in the hyperbaric chamber, there is no need for concern since the studies by Jackson et al. (1) have shown that titanium would not be expected to burn under any pressure when the oxygen concentration is less than 35%. However, if the items are exposed to pure oxygen, which would be the case inside a hyperbaric monoplace chamber or inside an oxygen hood, there is a potential fire hazard, but only if the titanium item breaks and a fresh un-oxidized surface is formed. Although unlikely, it is not impossible that the frames of titanium eye- glasses or a titanium earring might break when manipulated by the anxious patient during hyperbaric oxygen therapy. Titanium watches and medical replacement structures, on the other hand, are not prone to breakage and would not be likely to pose a problem, since unruptured and hence oxidized titanium will ignite and burn only at temperatures above 1200°C (1).
The question regarding the use of products containing titanium or titanium alloy results from research that may support the recommendation that these products be excluded from hyperbaric chambers. The research was performed under dynamic flow conditions with pure oxygen streaming past the fresh titanium surface, an oxygen partial pressure of 4.4 ATA (446 kPa) was sufficient to ignite and propagate the reaction. In the same study using other configurations, tensile rupture of unalloyed titanium (and hence formation of a fresh titanium surface) in gaseous oxygen at 6.1 ATA (618 kPa) at room temperature was shown to initiate a violent burning reaction [1].
The 2018 NFPA 99 Health Care Facilities Handbook, 14.3.2.5* prohibits equipment made from cerium, magnesium and magnesium alloys in the hyperbaric chamber [2]. It is important to note that Titanium and Titanium alloys are not specifically prohibited from the hyperbaric chamber in the NFPA 99 [3].
In a May 2016 post by the UHMS Safety Committee the following “generic statement” regarding external fixators was provided – “External fixators are, in general, safe in the monoplace chamber, but they should be padded to protect the chamber from damage if the patient has a seizure or if the fixator has contact with the chamber window in some manner”. Oxygen compatibility testing is complicated and there is little data available for materials in clinical chambers, self-ignition temperatures are generally unknown in special atmospheres. The concern is that if a piece of titanium is broken, enough energy could be produced by the stress fracture to ignite the titanium in a high oxygen environment. Equipment made of titanium and titanium alloys should be evaluated before use in the hyperbaric chamber [3].

A common example is the titanium eyeglass frames. It is unlikely that a patient wearing eyeglasses made from a titanium alloy would be able to break the frames with enough energy to initiate combustion at 30 psig and near 100% oxygen. Further, multiplace and monoplace chambers operate under the threshold temperatures for a flammability concern with solid titanium. The loose powder or fines of titanium that are a concern are not present with this device. Any amount of powder, or filings, should never be allowed into the chamber. Manipulation of eyeglass frames or jewelry while in the hyperbaric chamber should be prohibited. Evaluate each piece of equipment containing titanium or titanium alloys before using in the chamber, document the process, solid titanium is safe to use in the chamber during normal operations [3].
It is important to note that the conditions under which the tests were performed (4.4 ATA and 6.1 ATA) are greatly outside of the hyperbaric conditions utilized in most hyperbaric centers. The takeaway, focus on preventative or mitigating measures. Ensure all potential ignition sources are eliminated. Confirm the patient, chamber and wall grounding systems are adequate. Take mitigating measures to prevent damage to the external fixator that could result in a “fresh titanium” surface and prevent damage to the chamber acrylic (e.g., wrap in a moistened 100% cotton towel).
References
1. HINK J, JANSEN E. Commentary: Titanium in a hyperbaric oxygen environment may pose a fire risk. Aviat Space Environ Med 2003; 74: 1301–2
2. NFPA 99 Health Care Facilities Handbook 2018 edition
3. uhms.org/resources/medfaqs-frequently-asked-questions-faq/search/162-item-approval.html?yrfaqsearch=titanium
Feb 24, 2022
Eugene Worth
MD, M.Ed., FABA, ABPM/UHM
Barbara:

Jeff did the scientific heavy lifting for this question. So, I will keep this short and sweet:
1) Our 'go/no-go' lists need to be reviewed and modified whenever new science is available,
2) The attached paper was referenced by Jeff. I'm including a copy for your review. However, it is physically impossible to 'break' a piece of titanium or titanium alloy (like eyeglass frames or external fixators) in order to have a 'fresh' surface that can be exposed to oxygen. And, the experiment done was at over 4ATA and 100% Oxygen ... No fire of any sort at clinical pressures.

Bottom line: I don't even ask about titanium products. Period. End of story. I'd be much more worried about the fixator device scratching my acrylic. That would get me bent out of shape.

All the best!

gene worth
Feb 24, 2022
Barbara Keller
RN, MSN, CWS
Thank you Jeff and Dr. Worth. I feel much better about the decision of whether to or not to put an external fixator in the chamber. I appreciate all of the research you have done to provide the education and evidence based practice information.

Have a great day!
Feb 24, 2022
Eugene Worth
MD, M.Ed., FABA, ABPM/UHM
Just one other mindless doodle for you to consider. Whenever I read a scientific paper (like the titanium and hyperbaric oxygen paper above), and the conclusion says "may" do this ... that should trigger the inquisitiveness to look carefully at the real scientific data presented in the article. Do not pay attention to conjecture!

This paper started a hysteria within the hyperbaric community that titanium (of any sort) "may" be a fire risk. Not reading carefully to find out that the lowest pressure in 100% oxygen was 4.4ATA, way out of the range of normal clinical hyperbaric treatments. No matter what the material, they did not demonstrate any fire risk.

Therefore, whenever you see a paper that has the word "may" in the conclusion section, you can feel confident in replacing that with "may not" and be equally valid in the conclusion.

Just my parting thoughts.

gene
Feb 24, 2022
Barbara Keller
RN, MSN, CWS
Thanks
Feb 25, 2022
* Information provided without clinical evaluation and is not intended as a replacement for in-person consultation with a medical professional. The information provided through Curbside Consult is not a substitute for proper training, experience, and exercising of professional judgment. While every effort has been made to ensure the accuracy of the contents, neither the authors nor the Wound Reference, Inc. give any guarantee as to the accuracy of the information contained in them nor accept any liability, with respect to loss, damage, injury or expense arising from any such errors or omissions in the contents of the work.