Removing nail polish before surgery is a non-negotiable rule mandated for patient safety. This policy ensures the anesthesia team can accurately and instantly monitor a patient’s physiological status during sedation. Accurate monitoring allows the medical team to detect subtle changes in oxygen levels and circulation, enabling them to react quickly to prevent complications. Nail polish removal directly impacts the efficacy of medical devices and traditional methods of physical assessment used to protect the patient under anesthesia.
How Nail Polish Blocks Oxygen Monitoring
The primary reason for bare nails is the requirement for an unobstructed reading from the pulse oximeter, a small, clip-like device placed on the fingertip. This non-invasive device measures the oxygen saturation of the hemoglobin in the blood (SpO2), providing a moment-to-moment check on respiratory function. The pulse oximeter operates by emitting two specific wavelengths of light—red and infrared—through the tissue of the fingertip.
Hemoglobin saturated with oxygen absorbs more infrared light, while deoxygenated hemoglobin absorbs more red light. By measuring the difference in light absorption as blood pulses through the finger, the device calculates the percentage of oxygenated blood. Colored nail polish, particularly darker or opaque shades, contains pigments that absorb or scatter these light wavelengths. This physical blocking prevents the sensor from receiving an accurate signal from the underlying blood.
When light is absorbed by the polish, the pulse oximeter may display an artificially low reading or fail to register any reading at all. An inaccurate reading can mask a patient’s true oxygen status, delaying the medical team’s response to a dangerous drop in blood oxygen levels (hypoxia). The interference caused by these pigments compromises the continuous safety check the pulse oximeter provides.
Visual Clues for Anesthesia Teams
Beyond technical interference, the natural nail bed serves as a simple, quick visual indicator of peripheral circulation and tissue oxygenation. The translucent skin and tissue beneath the nail allow the medical team to observe the color of the underlying capillary beds. This visual assessment provides a traditional, immediate safety measure that complements machine-based monitoring.
A standard visual check is the capillary refill time, which assesses how quickly blood returns after light pressure is applied to the nail bed. A slow return of color signals poor peripheral perfusion or circulation issues, potentially indicating low blood pressure or shock. Furthermore, a bluish discoloration of the nail bed, called cyanosis, is a physical sign of reduced oxygen levels in the blood.
Nail polish, regardless of color, obscures these natural color changes and prevents the capillary refill test. The presence of polish can hide the subtle onset of cyanosis, removing a valuable visual cue for the anesthesia team. The ability to confirm a machine reading with a simple physical check is an important layer of redundancy for patient safety during the procedure.
Specific Concerns with Artificial Nails
Artificial nail enhancements, such as acrylics, gels, or dips, present unique concerns that necessitate their removal before surgery, even if clear. The thickness and material composition of these enhancements make it challenging to securely place the pulse oximeter sensor. The thickness increases the distance between the light source and the sensor, which distorts the light signal and leads to unreliable oxygen readings.
Artificial nails also introduce a risk of infection, regardless of whether polish is applied. The space between the natural nail and the enhancement can harbor bacteria and fungi, which are difficult to eliminate even with rigorous scrubbing. This increased bacterial load heightens the risk of a surgical site infection (SSI) for the patient.
In an emergency, the medical team may need to access the nail bed for a procedure or injection, which is complicated and delayed by the hard, thick nature of artificial materials. The time required to remove an artificial nail in a situation requiring immediate intervention can be detrimental. These material and hygiene factors make the removal of all nail enhancements a standard practice.
Pre-Surgical Preparation Guidelines
To ensure the safest monitoring, patients should remove all nail polish and artificial nail enhancements from their fingers before arriving at the hospital. Acetone or a similar remover should be used to ensure no residue, including clear base or top coats, remains on the nail bed. Complete removal is the most straightforward way to comply with safety protocols.
If a patient has a permanent enhancement, such as a difficult-to-remove gel manicure, it is usually only necessary to have one finger completely bare. The index finger is the most common site for oximeter placement, and removing the polish from just this nail is often an acceptable compromise. Patients with permanent nail tattoos or other unique circumstances should contact their surgical unit or anesthesiologist in advance. Following these guidelines ensures the medical team has the clearest view of a patient’s oxygenation and circulation status throughout the surgical process.