Pitfalls in the use of personal protective equipment during aerosol-generating operations on COVID-19 patients

In recent months, healthcare organizations across the world have been working to limit COVID-19 exposure to medical personnel during surgical procedures. Guidelines have been proposed for treating specific populations such as trauma victims, cancer patients, patients with laryngotracheal stenosis, as well as mechanically ventilated patients requiring tracheostomy. While published guidelines provide a logical framework for caring for COVID-19 patients in the operating room (OR), there remains some practical aspects regarding the specific usage of personal protective equipment (PPE) by surgeons that warrant further consideration. These include PPE donning/doffing, patient transport, and equipment failure. This commentary represents a collaborative effort between surgeons and our hospital epidemiology and infection control (HEIC) leadership; in it we intend to summarize what evidence exists around these key operational points in OR care and recommend safety measures for surgeons performing aerosol-generating procedures.

With regards to PPE, there are a broad range of options including N95 masks and powered air-purifying respirators (PAPR). N95 masks are designed to remove more than 95% of all particles that are at least 0.3 microns (µm) in diameter. They filter ≈99.8% of particles with a diameter of ≈0.1 μm. However, the virus is spread not by itself, but by larger expelled respiratory droplets ranging from 1 to 100 µm and aerosols, which are tiny droplets about 1 µm in size. PAPRs have high efficiency (HE) filters which are 99.97% efficient against 0.3-µm particles, therefore N95 and PAPR should be relatively equivalent in protection against SARS-CoV2 exposure when properly used. It should be noted, however, that there is no randomized trial evidence supporting the use of N95 or PAPR over conventional medical masks in the care of patients with COVID-19 or other coronaviruses, and case-report-level evidence ¹ may now suggest that the risk of transmission may be lower than previously thought.

While N95 masks with face shields are adequate for airborne precautions, powered air-purifying respirators may be more comfortable and result in less skin damage when worn for extended periods of time, such as during surgery.^2,3 Regardless of choice, however, doffing and post-doffing cleansing of PPE are the highest risk parts of caring for patients with high-consequence infectious disease, with one simulation study that tracked contamination with fluorescent particles finding that 100% of health care workers made errors during PPE removal, with the hands and neck being common areas of contamination. ⁴ Quality improvement work, primarily from the Ebola literature, shows that having simpler doffing protocols, ⁵ a buddy system ⁶ for accountability, frequent assessment of technique, ⁷ and increased doffing space ⁶ improves rates of self-contamination. After doffing, safe transport of patients is a key area of failure as well. We recommend the following practice for doffing and transport after completion of a tracheostomy in a COVID-positive patient (Figure 1).

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Figure 1.

Recommended postoperative doffing and transport procedure after an aerosol-generating operation such as tracheostomy on a COVID-19-positive patient.

While the proper use of protective equipment is key, its failure at a crucial moment is always a concerning possibility, and contingency plans should always be discussed in a pre-operative huddle. Especially in high-risk aerosolizing cases such as tracheostomy, the intraoperative handling of the rare event of battery failure is paramount and having a backup battery in the OR is recommended. Batteries and equipment should undergo regular maintenance and testing, and manufacturer-recommended cleaning processes should be used so as not to damage the batteries’ function by saturating them with cleansing solution. Also possible during a case is dislodgement of the PAPR, with risk theoretically increased by wearing loupes or a headlamp underneath or on the outside of the PAPR hood. While most published guidelines do not recommend concurrent use of an N95 respiratory and a PAPR as each are adequate on their own, this has been shown to multiplicatively increase filtration protective power of these devices, ⁸ and it may be an effective strategy for those closest to the aerosolizing operative site (i.e. surgeons, anesthesiologist, and scrub nurse or technologist). In the authors’ personal experience, concurrent use of an N95 respirator during a case was beneficial during an accidental intraoperative dislodgment of a PAPR hood. Admittedly, the empiric evidence for this practice is sparse, and regional PPE availability and shortages should be considered when contemplating concurrent use. In the case of splashing of infected fluids onto the PAPR hood or face shield, visibility should determine the next step. If the splashed fluid impairs the operator, they should stop and proceed to the doffing area if possible to safely doff PPE and prevent self-contamination with respiratory secretions. Protocols should be developed to remove any visible respiratory secretions from the PAPR hood or face shield prior to doffing. Stopping an operation may not be easily possible, however (e.g. during bleeding or if the airway is open), so the surgeon and OR personnel should check PPE securement and integrity prior to beginning the operation and before critical or high-risk portions of the case. PAPRs with longer shrouds (the surrounding piece of the hood) may be less likely to dislodge, though evidence is admittedly limited for this recommendation. Finally, in addition to the risks of contamination, the noise generated from PAPRs as well as the reduction in speech intelligibility can result in reduced quality of communication during an operation. We recommend that during the surgical timeout the surgeon review carefully with the surgical, anesthesia, and nursing teams the critical steps of the operation to mitigate any potential communication barriers during the procedure and that ambient noise be kept to a minimum.

In our experience during the COVID-19 pandemic, OR safety has been a major concern, particularly during the care for affected patients requiring tracheostomy. Proper PPE use, transport, and intraoperative equipment failure have been the largest issues that we have encountered in our own practice, and the above recommendations in addressing challenges have been helpful for us. While these observations may not be fully generalizable, we hope they will be useful in helping reduce COVID-19 infections in surgeons and other healthcare workers in the care of our patients.