Removing nail polish, gel, and acrylics before surgery is a direct safety measure intended to protect the patient during anesthesia and the operation. This requirement is a significant part of the monitoring process surgical teams rely on to assess a patient’s well-being. Coatings on fingernails interfere with both electronic monitoring devices and the visual assessment techniques used by healthcare providers. Ensuring at least one finger is completely clear allows the anesthesia team to accurately track the patient’s physiological status in real-time.
The Primary Safety Device
The primary reason for clear nails is the necessity of using a pulse oximeter, a non-invasive device placed on a fingertip or toe. This machine uses light to measure the percentage of oxygenated hemoglobin in the blood, known as peripheral oxygen saturation (SpO2). The device works by shining two specific wavelengths of light—one red and one infrared—through the finger tissue. This measurement is continuously tracked during surgery because a drop in SpO2 is often the first sign of a serious complication, indicating issues with breathing, circulation, or anesthesia.
How Nail Coatings Interfere
Nail coatings, particularly dark or opaque colors, interfere with the pulse oximeter’s ability to accurately read the light passing through the finger. The pigments in the polish, especially shades like blue, green, black, or purple, absorb or scatter the specific red and infrared light wavelengths used by the device. This interference prevents the light sensor from getting a clean signal. When light is absorbed by the polish instead of the blood, the oximeter can produce a false reading, potentially reporting a high oxygen saturation level. Conversely, interference can cause a falsely low reading, which can lead to unnecessary medical interventions. The inaccurate data can delay the surgical team’s response to a genuine physiological problem. The thickness of the coating, such as with multiple layers of lacquer, also acts as a physical barrier that can weaken the light signal.
Visual Assessment of Patient Status
Beyond electronic monitoring, the anesthesia provider relies on visual and manual checks to evaluate a patient’s circulation and oxygenation. The color of the nail bed, the tissue beneath the fingernail, is a rapidly changing indicator of peripheral blood flow. A patient who is not getting enough oxygen may develop cyanosis, a bluish or grayish tint to the skin and mucous membranes. The nail bed is a prime location to spot this discoloration because the skin is thinner and the underlying capillary network is easily visible. Nail polish completely obscures this visual cue, making it impossible to detect cyanosis early. A second manual assessment is the capillary refill time, which involves gently pressing the nail bed until it blanches. A prolonged refill time suggests poor peripheral circulation, which is a sign of potential shock or dehydration. This manual check is completely masked by any opaque nail coating.
Special Considerations for Artificial Nails
Artificial nail enhancements, including gels, shellac, acrylics, and extensions, pose more complex problems than standard nail lacquer. The material is significantly thicker and more rigid than polish, making it harder for the pulse oximeter’s light to penetrate the tissue effectively. This increases the likelihood of a failed or unreliable reading from the electronic monitor. Artificial nails are chemically bonded and cannot be quickly removed in an emergency with a standard polish remover pad. When a reliable SpO2 reading is urgently needed, the inability to quickly remove the artificial nail can compromise patient safety. Artificial nails also present an infection risk, as the space between the natural nail and the enhancement can harbor microorganisms difficult to eliminate through routine surgical hand scrubbing. Patients are advised to remove all artificial enhancements completely before arriving for their procedure.