C-Arm Drape Contamination: Why the Top of the Image Intensifier Poses the Greatest Risk
By: AORN Staff
Published: 6/18/2025
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The C-arm is used in many surgical procedures—but its drape is a known high-risk area for sterile field contamination. One study found that 17 percent of C-arm drapes were contaminated immediately after initial draping. Within just 20 minutes, that number jumped to 50 percent, and by 80 minutes, 80 percent were contaminated.
But the “why” behind this rapid contamination isn’t always clear-cut. That’s because the literature on C-arm drape and associated sterile field contamination is still evolving, explains AORN’s sterile technique expert Julie Cahn, DNP, RN, ACNS-BC, CNS-CP, NPD-BC, CNOR, FAORN.
“We do know that C-arm drape contamination occurs frequently and rapidly and is associated with lateral position changes,” Dr. Cahn said.
So, where is contamination most likely to occur—and how can teams mitigate the risk? Dr. Cahn says several high-risk areas demand attention and proactive strategies.
Top C-Arm Contamination Risks
Risk #1: Lateral position changes of the C-arm pose an increased risk for sterile field contamination
Contamination is highest on the top of the image intensifier (see diagram), where it comes in close contact with the unsterile, undraped portions of the C-arm when the device is rotated into a lateral position.
This is significant, Dr. Cahn explained, because the area of the sterile field closest to the image intensifier in lateral position—opposite where the surgeon typically stands—has also been reported as the most contaminated.
Risk #2: Raising the x-ray tube of the C-arm raises the sterile field drape from a contaminated area to the level of the sterile field
The x-ray tube of the C-arm carries a high risk of contamination due to how it moves from beneath the table to a position near the surgeon. As it swings upward, the drape is pulled from below the sterile field level to the level of the OR bed.
This is a concern, Dr. Cahn notes, because areas below the instrument table and OR bed are known to have higher levels of contamination.
How to Minimize Risk of C-arm Drape and Sterile Field Contamination
Given the high risk for C-arm contamination shown in current research, Dr. Cahn points to six essential safety practices from the AORN Guideline for Sterile Technique:
- Drape the C-arm as close to the time of use as possible.
- Follow the drape manufacturer’s instructions for use.
- Treat the top of the C-arm drape as contaminated after draping.
- If a scrubbed person touches the C-arm drape or a drape used to protect the sterile field during lateral positioning, they should change gloves immediately afterward.
- Prevent the draped C-arm from contacting the patient or sterile field whenever possible.
- Assemble an interdisciplinary team to develop a standardized strategy for C-arm draping in lateral positions to help prevent contamination of the sterile field.
Better Draping Methods to Consider
A key topic for the interdisciplinary team should be selecting a C-arm draping method that reduces risk from the x-ray tube and image intensifier.
Rather than clipping a standard three-quarter sheet to the sterile field, the team might evaluate:
- A modified clip draping method, which accordion-folds the sheet into a pouch that captures the x-ray tube during lateral positioning.
- A commercially manufactured C-arm drape with a built-in pouch designed to receive the x-ray tube.
Both methods have shown effectiveness in keeping contamination lower—well below the sterile field level.
Additional sterile draping can also be applied before lateral rotation to help protect the surgical field from contamination caused by the image intensifier.
Strengthen Sterile Technique Skills with Perioperative Education Tools
- Periop 101: A Core Curriculum™ offers a learning module on Surgical Draping that incorporates a lesson in Draping OR Equipment, which includes drapes for c-arms. This learning module is included in the OR and ASC learning plans.
- Help both novice and tenured perioperative staff solidify best practices with over 40 mobile-friendly, video-based courses on patient and worker safety within the AORN CineMed Video Library. Assign the Sterile Technique and Draping course to the entire team. Nurture learners with Contact Hours and verify competency via posttests.
- Embed best practices through an online subscription to eGuidelines+, a one-stop, facility-wide resource for real-time clinical reference. Refer to the latest AORN Guideline for Sterile Technique, review quick guides to best practices on sterile technique and surgical draping, and find links to publicly available drape manufacturers’ instructions for use.
