Operative Fires: Variables Associated with Polymethylmethacrylate Flammability

Area of Science:

• Surgical Safety
• Biomaterials Science
• Fire Safety Engineering

Background:

• Operative fires pose significant risks, with an estimated 650 occurring annually in the US.
• Electrocautery devices and polymethylmethacrylate (PMMA) are primary ignition and fuel sources in operating room fires.
• Limited formal studies exist on PMMA flammability when exposed to electrocautery.

Purpose of the Study:

• To investigate the flammability of polymethylmethacrylate (PMMA) when subjected to electrocautery.
• To determine the reaction of PMMA to electrocautery ignition in a controlled laboratory setting.
• To assess the impact of antibiotic additives on PMMA flammability.

Main Methods:

• A cadaveric leg model was used to simulate PMMA application during total knee arthroplasty (TKA).
• Two brands of PMMA, with and without antibiotics, were tested for flammability using electrocautery.
• Flammability was assessed by visual sparks/flames, heat via thermal imaging, and video recording over 15-minute intervals.

Main Results:

• Polymethylmethacrylate (PMMA), with and without antibiotics, demonstrated flammability when exposed to electrocautery.
• All ignition events occurred within 7 minutes of PMMA monomer and powder mixing.
• Antibiotic additives were associated with increased PMMA flammability.

Conclusions:

• PMMA is highly flammable during its initial curing period when exposed to electrocautery.
• An "electrocautery timeout" of at least 7 minutes is recommended until PMMA is fully hardened.
• This measure aims to mitigate the risk of operating room fires caused by PMMA and electrocautery.