The sterile environment of the operating room (OR) requires strict control over contamination, a necessity that extends to every member of the surgical team. Surgeons and other personnel wear head coverings as a fundamental component of this infection control strategy. The primary purpose of this attire is to create a physical barrier, isolating potential sources of microorganisms and particles from the sterile surgical field. Head coverings are therefore a non-negotiable requirement for anyone entering the semi-restricted and restricted areas of the hospital.
Standard Surgical Caps and Bonnets
The most commonly observed head coverings in surgery are the standard surgical cap and the bouffant bonnet. The skullcap, or tie-back cap, is a close-fitting design often favored by individuals with shorter hair, typically secured with an adjustable tie at the back. Bouffant caps, resembling an oversized shower cap, are designed to accommodate long or voluminous hair, ensuring all strands are completely contained within the elasticized dome.
These caps are generally made from either disposable non-woven materials, such as spun-bond polypropylene (SBPP), or reusable, launderable fabrics like cotton or a cotton-polyester blend. Disposable options offer lightness and breathability, while reusable cotton provides comfort and superior moisture absorption for prolonged procedures. Guidelines mandate that the chosen headwear must confine all hair, covering the scalp, ears, sideburns, and the nape of the neck to prevent particle shedding.
Specialized Head Protection Systems
Beyond the standard fabric cap, certain procedures necessitate more comprehensive head protection, often involving specialized helmet systems. These are particularly common in orthopedic and trauma surgery where power tools generate high levels of particulate matter and aerosols. The surgical helmet system (SHS) consists of a lightweight helmet with an integrated fan and a disposable hood, sometimes referred to as a toga system.
The integrated ventilation system within the SHS serves a dual function: it keeps the surgeon cool and dry during lengthy operations and delivers a continuous flow of filtered air. This positive pressure system prevents external contaminants from entering the breathing zone, offering respiratory protection for the wearer. The system also includes a clear visor that protects the surgeon from blood and infectious fluid splashes, while ensuring no skin cells or hair particles fall into the patient’s open wound.
The Scientific Rationale for Head Coverage
The reason for covering the head is to mitigate the risk of a surgical site infection (SSI) caused by microbial shedding. The human body continuously sheds skin squames, with up to 10 million particles released daily, approximately ten percent of which carry viable microorganisms. Hair can harbor pathogenic bacteria, including Staphylococcus aureus, which has been implicated in SSI outbreaks traced back to surgical personnel.
Complete hair coverage traps these bacteria-carrying particles and prevents their dispersal into the sterile field. Professional guidelines, such as those from the Association of periOperative Registered Nurses (AORN), recommend that all hair, including facial hair like beards, must be contained when entering restricted areas. While conclusive evidence linking head coverings directly to a reduction in SSI rates is mixed, the potential benefit of reducing patient exposure to staff-shed microorganisms supports the practice as a proactive safety measure.
Integrating Head Gear with Full PPE
The surgical head covering functions as one part of a larger ensemble of Personal Protective Equipment (PPE) that must be integrated seamlessly. The head cap is one of the initial items donned, preceding the surgical mask and eye protection, to establish a clean foundation for the protective barrier. It is important that the cap is pulled low enough to completely cover the ears and hairline, ensuring no gaps exist at the perimeter.
This full coverage allows the cap to interface correctly with the surgical mask or respirator, which is placed next. The edge of the cap and the top of the mask are designed to meet without any exposed skin, creating a continuous barrier that prevents contamination. When removing the gear, or doffing, the head covering is typically one of the last items taken off to ensure the hair remains contained until the risk of environmental exposure is minimized.