Carbon Dioxide Exposure Resulting From Hood Protective Equipment Used in Joint Arthroplasty Surgery

To protect both the surgeon and patient during procedures, hooded protection shields are used during joint arthroplasty procedures. Headache, malaise, and dizziness, consistent with increased carbon dioxide (CO₂) exposure, have been anecdotally reported by surgeons using hoods. We hypothesized that increased CO₂ concentrations were causing reported symptoms.

Six healthy subjects (4 men) donned hooded protection, fan at the highest setting. Arm cycle ergometry at workloads of 12 and 25 watts (W) simulated workloads encountered during arthroplasty. Inspired O₂ and CO₂ concentrations at the nares were continuously measured at rest, 12 W, and 25 W. At each activity level, the fan was deactivated and the times for CO₂ to reach 0.5% and 1.0% were measured.

At rest, inspired CO₂ was 0.14% ± 0.04%. Exercise had significant effect on CO₂ compared with rest (0.26% ± 0.08% at 12 W, P = .04; 0.31% ± 0.05% at 25 W, P = .003). Inspired CO₂ concentration increased rapidly with fan deactivation, with the time for CO₂ to increase to 0.5% and 1.0% after fan deactivation being rapid but variable (0.5%, 12 ± 9 seconds; 1%, 26 ± 15 seconds). Time for CO₂ to return below 0.5% after fan reactivation was 20 ± 37 seconds.

During simulated joint arthroplasty, CO₂ remained within Occupational Safety and Health Administration (OSHA) standards with the fan at the highest setting. With fan deactivation, CO₂ concentration rapidly exceeds OSHA standards.