During both brain and spine surgery, we use electrocautery to control bleeding. Bipolar cautery creates a circuit between the forcep tips, and the electric current flows smoothly between the active and return electrode. Only minimal and focal patient tissue, in between the tips, is exposed to the current. Monopolar cautery, however, creates a circuit between the cautery device and the entire patient body. The active electrode concentrates the current in its small tip before cutting. The electricity passes through the patient’s body, so the exiting current is dispersed over a greater area, creating a plume of smoke, breathable by operating room (OR) personnel.
Electrosurgical smoke contains potentially hazardous organic and inorganic compounds. A 2012 study indicated that the amount of surgical smoke produced in a simple cosmetic surgery was equivalent to 27 to 30 cigarettes. Plumes have been found to contain as much as 3-51 parts per million (ppm) hydrogen cyanide, 2-8 ppm acetylene, and <1 ppm 1,3- butadiene. Luckily electrosurgical plumes may contain significantly lower concentrations
of hydrocarbons than cigarette smoke.
Bacterial exposure has been shown to occur during surgery. Although never confirmed, this finding suggests that disease could be transmitted from a bacterially infected patient to OR staff. Viral DNA has been identified in surgical smoke. Viable melanoma cells have been found in smoke plumes created during surgery on mice with melanoma. No studies have yet demonstrated the transmission of viruses or cancer during surgery using electrocautery.
A recent study was published in JAMA Surgery, assessing the risk of SARS-CoV-2 transmission via the cautery smoke plume. After all, we have been told this year COVID-19 could be acquired through multiple masks, proximity, or inorganic surfaces. It turns out that respiratory RNA viruses with a lipid bilayer, like SARS-CoV-2, are more susceptible to high temperatures than other viruses. The tip temperature of monopolar cautery devices, like the Bovie (used in neurosurgery), ranges from 100-1200 degrees Celsius. Therefore it is presumed that monopolar cautery should be hot enough to inactive SARS- CoV- 2. Turns out the suspicion was correct. In this 2021 study, no virus was recovered from any electrocautery procedure performed. SARS-CoV-2 was not detectable in the aerosolized cautery plume, so there essentially is no risk for transmission to healthcare workers via this route.
Behavior and protective measures are now in place to limit exposure to cautery smoke, while we continue to assess risks. Surgeons, techs and nurses have always worn masks during surgery. Suction devices, at the surgery site, now are used to locally filter away any airborne particles prior to reaching anyone’s face region.
This being said, this JAMA article dispels another proposed transmission route for COVID-19. Anyone who says otherwise, must be smokin’ something.
As pulmonary physician Dr. Adam Lawton previously wrote:
“If you’re a new single-stranded RNA virus looking to survive in this big bad universe, rule number one is surely not to pick a fight with the only double-stranded DNA-based organism that can sequence your genome, and has eradicated more species before than any other living thing”