Bair Hugger Litigation Update


Bair Hugger Litigation Update and Resources


Bair Hugger®/3M (Forced-air Warming) Litigation Update

Editors note: this page is a resource for healthcare providers looking for information about the Multi-District mass-tort litigation (MDL 15-2666) against 3M, the manufacturer of Bair Hugger® forced-air patient warming systems, for allegedly causing devastating orthopedic implant infections. All of the information shared on this page is publicly available. It can be accessed via the government’s Pacer system It requires registration and small payments to access the records. In order to make it easier for you, we have assembled and summarized the information.

Over 4,000 lawsuits have been lodged against 3M (May 2017). General discovery has closed, and bellwether cases have been scheduled for trial in April 2018.

A series of reports from the plaintiffs’ experts recently became publicly available through the court. The experts analyzed existing data, 3M’s internal communications, and sworn deposition testimony of 3M employees and ex-employees. In some cases they have done their own original research.

Summary abstracts as well as the full reports are available below:

Hazard Analysis Report: Bair Hugger Patient Warming System (Yadin David, Ed.D., P.E., C.C.E.)


Risk of Patient Safety Posed by Bair Hugger Patient Warming System (Dr. William Jarvis)


Does the Use of Bair Hugger During Hip and Knee Joint Replacement Surgeries Increase Risk for Deep Join Infections? (Jonathan M. Samet, MD, MS)


Effect of Heated-Air Blanket on the Dispersion of Squames in an Operating Room (Said Elghobashi)


Testing of Bair Hugger Warming Systems for Particle Emissions (Michael W. Buck)


Plaintiffs’ MEMORANDUM OF LAW in support of motion for leave to amend master long form and short form complaints to add claim for punitive damages

Contamination Confirmed

Statements by manufacturers of two forced-air patient warming devices (Stryker, manufacturer of Mistral, and 3M, manufacturer of Bair Hugger) seem to confirm contamination in or by the devices.


The instructions for use for Mistral include the following boxed warning:

Bair Hugger

Al Van Duren, 3M’s Scientific Affairs Director, testifying under oath on behalf of his employer, stated as follows:

“3M is not disputing that the Bair Hugger blower and hose can harbor bacteria inside the device.”

An internal email by Van Duren, revealed by 3M in a publicly available document filed in the Multi-District Litigation, was even more explicit:

“Actually there is evidence that FAW use increases risk.” (emphasis added)

In his deposition, Van Duren claimed that the above comment was “careless.” What he should have said, Mr. Van Duren testified, “was that there was suspicion that forced-air warming increases risk….”

Other documents reveal that as early as 1996, the manufacturer of Bair Hugger admitted the following to the FDA as part of “Other Safety Concerns”:

“1. Contamination. Airborne contamination from air blown intraoperatively across the surgical wound may result in airborne contamination.” (emphasis added)

3M Affirmative Defenses

In response to claims that Bair Hugger caused orthopedic implant infections by contaminating the sterile field with pathogens, 3M has asserted certain “Affirmative Defenses.” An affirmative defense is, according to one legal dictionary, “a set of facts that operates to defeat a claim even if the facts supporting that claim are true.”

In other words, 3M claims that it is not liable—even if Bair Hugger did cause the thousands of orthopedic infections as alleged.

Why? What are the facts that, according to 3M, free it from any responsibility for the catastrophic infections?

Here are two of them—in 3M’s exact words:

  • “Plaintiff’s claims are barred, in whole or in part, by the doctrine of informed consent.”
  • “Plaintiff’s claims may be barred by virtue of the intervention of a learned intermediary or intermediaries to whom the duty to warn was discharged and over whom Defendants had no control.”

What is Informed Consent?

Generally, it means that a patient must be told all of the potential benefits, risks, and alternatives involved in any surgical procedure, and the doctor must obtain the patient’s written consent to proceed. The concept is based on the principle that a physician has a duty to disclose information to the patient so he or she can make a reasonable decision regarding treatment.

Evidence at trial will reveal whether any patient was actually told of the risks of forced-air warming—and of the alternatives.

What is Intervention by a Learned Intermediary?

The Learned Intermediary Doctrine provides that a manufacturer of a medical device discharges its duty to warn users of the risks of its products by warning the physician of the risks. Being fully warned, the duty then falls on the physician, not the manufacturer.

Evidence at trial will reveal whether surgeons and anesthesiologists were actually told of the risks of forced-air warming.


CASE 0:15-md-02666-JNE-FLN



PRETRIAL ORDER NO. 20: Third Amended Scheduling Order (excerpts)

The Court HEREBY ORDERS that the following third amended schedule shall govern this Consolidated Action.

  • A “Science Day” educational tutorial was held off the record on May 19, 2016.
  • Fact discovery on the issue of general causation was to be completed by March 20, 2017.
  • Motions to amend the Amended Master Short Form and Master Long Form Complaints to include punitive damages claims were due April 21, 2017.
  • Bellwether Trial Selection Process:
    1. The Court randomly selected 150 cases from the bellwether pool, which consisted of cases filed in, removed to, or transferred to this Consolidated Action on or before December 19, 2016.
    2. On May 30, 2017, the Court announced 8 selections for the Final Bellwether Trial Pool. The parties each exercised a strike.
    3. The order of the bellwether trials will be as follows:
      1. Kamke v. 3M Co., et al. – 16cv1225 (JNE/FLN)
      2. Nugier, et al. v. 3M Co., et al.  – 16cv4246 (JNE/FLN)
      3. Walker v. 3M Co., et al. – Ramsey Cty. Case No. 62-cv-16-1257
      4. Knuteson v. 3M Co. – 16cv1088 (JNE/FLN)
      5. Skaar, et al. v. 3M Co., et al. – 16cv2969 (JNE/FLN)
      6. Gareis v. 3M Co., et al. – 16cv4187 (JNE/FLN)
  • Experts on General Causation:
    1. Initial expert reports and disclosures of the identity of expert witnesses under Rule 26(a)(2) were to be exchanged on or before March 31, 2017.
      1. Rebuttal expert reports and disclosures of the identity of rebuttal expert witnesses were to be exchanged on or before June 3, 2017.
      2. Depositions of expert witnesses must be completed on or before August 16, 2017
    2. Initial disclosures required by Rule 26(a)(1) that pertain to the bellwether-case-specific issues shall be completed on or before June 15, 2017.
    3. Daubert motions and other dispositive motions (as defined under the Local Rules of this Court) on general causation and issues not specific to bellwether cases may be filed no later than September 5, 2017.
  • Bellwether-case-specific discovery shall be commenced no earlier than June 2, 2017, and shall be completed no later than October 16, 2017.
  • Bellwether-case-specific dispositive motions shall be filed no later than November 15, 2017.
  • The first bellwether trial shall commence February 26, 2018.

Click here for downloadable PDF.