It is a standard safety measure that all patients must remove fingernail polish, gel, and artificial nails before undergoing surgery or receiving anesthesia. This requirement is focused on patient safety, ensuring medical professionals can continuously and accurately monitor a patient’s oxygen levels and overall circulatory status while they are unconscious. This monitoring is paramount, as early detection of any physiological change is the best way to prevent complications during and immediately following the operation.
Understanding Oxygen Monitoring During Surgery
The primary device affected by nail coverings is the pulse oximeter, a non-invasive monitor that measures the oxygen saturation of the blood, known as SpO2. This clip-like device is typically placed on a fingertip, toe, or earlobe, and it uses light to measure the percentage of hemoglobin carrying oxygen. The ability to track SpO2 is fundamental during surgery because it provides real-time data on how effectively the patient’s lungs and heart are delivering oxygen to the body.
Maintaining proper oxygen levels is especially important when a patient is under anesthesia, which can affect normal breathing patterns. A sudden drop in SpO2, known as hypoxemia, signals that the patient is not getting enough oxygen, a condition that needs immediate intervention. The pulse oximeter allows the anesthesia team to detect this dangerous trend quickly, often before other physical symptoms become apparent. This device is one of the most reliable and immediate indicators of a patient’s respiratory status throughout the procedure.
Physical Interference with Sensor Technology
Nail polish, particularly darker colors, interferes with the pulse oximeter by disrupting the light-based measurement mechanism. The sensor operates by shining two different wavelengths of light—red and infrared—through the finger and measuring how much light is absorbed by the blood. Oxygenated and deoxygenated hemoglobin absorb these light wavelengths differently, allowing the device to calculate the SpO2 percentage.
The pigments in nail polish, especially black, blue, and green, absorb or scatter these light beams, which can lead to inaccurate or failed readings. This absorption creates an artifact that can cause the oximeter to report a falsely low oxygen saturation value. If the interference is significant, the machine may not produce any reading at all, leaving the medical team without vital information. Even thick layers of clear polish or gel manicures can sometimes interfere by creating a physical barrier or causing light reflection issues.
The Need for Visual Circulation Checks
Beyond technological interference, a second reason for clear nails is the necessity of visual assessment. Anesthesiologists and nurses rely on the natural appearance of the nail bed as a quick, non-instrumental way to check a patient’s circulation and oxygenation. The tissue underneath the nail should be a healthy pink color, indicating good blood flow.
Changes in this color, such as the nail bed turning a bluish or dusky shade, are a physical sign of poor circulation or low blood oxygen, a condition called cyanosis. A layer of polish completely obscures this visual sign, delaying the recognition of a potentially dangerous situation. Healthcare providers also manually perform a test called the capillary refill time to check peripheral circulation. This involves pressing on the nail bed until it turns pale and timing how quickly the pink color returns, which should typically be within two to three seconds. Nail polish or artificial nails make this manual assessment impossible.
Guidelines for Pre-Surgical Nail Preparation
To ensure proper monitoring during surgery, all forms of nail covering must be removed before arriving at the hospital. This includes traditional nail polish, shellac, gel polish, dip powder, acrylics, and any applied nail decorations. Complete removal of all enhancements prevents interference with monitoring equipment and preserves the ability to perform visual checks.
While some hospitals may permit one finger to be cleared for the pulse oximeter, it is generally safer to remove all polish from all fingernails and toenails. Certain procedures may require monitoring sites other than the fingers, such as the toes, making it advisable to clear those as well. Patients should proactively plan for the removal of artificial enhancements, as they often require specialized soaking and filing that can be time-consuming.