Bair Hugger – Emerging Litigation

Bair Hugger is a hot air warming blanket for patients undergoing surgery. It helps anesthetized patients regulate their body temperature and prevent hypothermia. It works by forcing hot air through a hose into a special blanket that is draped over the patient.

Bair Hugger therapy consists of warming units and disposable blankets that distribute warm air across the patient before, during and/or after surgery.

With 19 blanket models (including seven pediatric and three sterile blanket designs), Bair Hugger therapy is the only one of its kind to guarantee patient normothermia important source. Each Bair Hugger blanket features a soft, non-woven material that is comfortable against the patient’s skin and each is designed to distribute warm air effectively and efficiently across the patient’s body.


How Bair Hugger Therapy Works?

Bair Hugger warming units filter air using a 0.2 micron filter, then force warm air through Bair Hugger disposable blankets which cover patients before, during and after surgery. The warming unit is supposed to force the air gently and evenly throughout the blanket.

Bair Hugger blankets are designed to use pressure points on the patient’s body to prevent heat from reaching areas that are at risk for pressure sores or burns. The blankets also include drain holes where fluid passes through the surface of the blanket to the linen underneath. This is supposed to reduce the risk of skin maceration and reduce the risk of unintended cooling because of heat loss from evaporation. Bair Hugger blankets are disposable in order to reduce the chance of infection transmission from one patient to another.

3M also markets a Bair Hugger 241 Blood Fluid Warming set which can be connected to warming units.

Bair Hugger Products

  • Warming Units
    • Model 505 warming unit
    • Model 750 warming unit
    • Model 775 warming unit
  • Blankets
    • Intraoperative Blankets
      • Upper Body Model 552
      • XL Upper Body Model 523
      • Lower Body Model 525
      • Dual Port Torso Model 542
    • Postoperative Blankets
      • Full Body Model 300
      • Chest Access Model 305
      • Pediatric Model 310
      • Multi-Access Model 315
    • Pediatric Blankets
      • Small Lower Body Model 537
      • Pediatric Long Model 530
    • Underbody Series
      • Pediatric Underbody Model 555
      • Large Pediatric Underbody Model 550
      • Adult Underbody Model 545
      • Spinal Underbody Model 575
      • Lithotomy Underbody Model 585
      • Full Access Underbody Model 635
      • Sterile Full Access Underbody Model 637
    • Specialty and Cardiac Blankets
      • Outpatient with booties Model 110
      • Outpatient Model 111
      • Cath Lab Model 560
      • Surgical Access Model 570
      • Full Body Surgical Model 610
      • Sterile Cardiac Model 630
      • Sterile Cardiac Access Model 645
    • Accessories
      • Model 505 Hose
      • Model 750 Hose
      • Model 505 Filter
      • Model 750 Filter
      • Clear Drapes
      • Hose Clip
      • Sheet Clip
      • Temperature Test Kit
      • Model 505 Rolling Cart
      • Model 700 Rolling Cart
      • 241 Blood/Fluid Warming Set

Bair Hugger’s FDA History

The U.S. Food and Drug Administration (FDA) cleared the first Bair Hugger warming system in 1987 through the 510(k) premarket clearance program as a substantially equivalent device. The FDA regulates drugs and medical devices and must approve or clear devices before they enter the market. Under the 510(k) program, the FDA can clear a medical device without clinical proof that it is safe if it is similar enough to a previous device that is already on the market.

The FDA issued 12 additional clearances for Augustine Medical devices through the 510(k) premarket program from 1990-2002. After Augustine Medical changed its name to Arizant, the FDA issued two more clearances for medical devices through the 510(k) program from 2004-06.

The FDA has not issued a recall of Bair Hugger devices, but numerous adverse events have been reported to the FDA. The majority of adverse events involve burns from prolonged exposure to heat during surgery or equipment malfunctions, resulting in cold air blowing during surgery.

As of this time, there has not been a recall of Bair Hugger warming blankets related to deep joint infections. However, the investigation into this device, from a legal standpoint, is still at its early stages. However, even the inventor of the Bair Hugger warming blanket (Dr. Scott Augustine) has asserted his concern that the device is a danger to surgical patients because the forced air can spread bacteria associated with hospital-acquired infections.

Lawsuit – Failure to Warn About Risk of Infection

The lawsuits claim 3M knew about the risks for infection but did not warn healthcare providers about that risk. The lawsuits also claim 3M and Arizant attempted to conceal and discredit scientific data that could be associated with risks linked to the device.

Lawsuits are being filed alleging that the Bair Hugger causes bacteria and other contaminants to be circulated from the Operating Room floor onto a patient’s open wounds. Patients undergoing surgery for hip and knee replacement may be especially susceptible.


The Bair Hugger is supposed to reduce the risk of infections, but it may actually cause infections by blowing bacteria-contaminated air into a patient’s open surgical wounds. The most serious potential side effects, problems and risks caused through the use of a Bair Hugger warming blanket are deep joint infections.

The risk of infection is especially serious for patients undergoing heart surgery to implant artificial valves or joint replacement surgery, especially hip replacements and knee replacements.

Factors that increase the risk for infection include:

  • Diabetes mellitus
  • Immune deficiencies (such as HIV, lymphoma)
  • Immunosuppressive treatments (such as chemotherapy or corticosteroids)
  • Obesity
  • Peripheral vascular disease (poor circulation to the hands and feet)

Some of the key signs and symptoms of an infected hip and knee replacement include:

  • Fatigue
  • Fevers, chills and night sweats
  • Increased pain or stiffness
  • Swelling
  • Warmth and redness around the wound
  • Wound drainage

When joint infection is suspected, early diagnosis and proper treatment increase the chances of a full recovery.

Other Injuries:

  1. Burns from Prolonged Exposure to Heat during Surgery
  2. Equipment Malfunction during surgery resulting in cold air blowing during surgery.


  • This serious complication often must be treated with multiple surgeries to replace the implant, wash out the joint and tissues, and administer intravenous antibiotics.
  • In severe cases, amputation, joint fusion, or removal and a two-stage revision surgery may be necessary.
  • Patients who are not candidates for a second surgery are usually treated with long term antibiotic suppression.

Case Review Focus Areas:

  1. Whether Bair Hugger Therapy was used on the patient?
  2. Surgery Details in which Bair Hugger Therapy was used?
  3. Did the patient have any preexisting conditions (Any joint problems or infections) or contraindications for Bair Hugger Therapy?
  4. Product Details of Bair Hugger Therapy
  5. Did the patient develop Complications after Bair Hugger Therapy?
  6. Treatment/Management of Complications
  7. Follow-up visits for treatment/management of injury/Additional surgeries
  8. Outcome/prognosis. Resolution of injury?

Specific Focus

Identify and report cases with the following scenarios:-

  1. No Injuries: Patient had Bair Hugger Therapy but did not develop any injuries
  2. No evidence for Bair Hugger Therapy usage: Hold case and communicate to client.
  3. Bair Hugger Therapy contraindicated in patient but still used

Missing Record Communication:

Identify and report on missing medical records/Product details

Apart from identifying critical missing records that are important for the case, provide a detailed outline on what records are needed, why we need them, how did we get a clue that these records are missing and whether the records missing are confirmatory/probable. This will also help in following up and retrieving the records.