CPT® Code 95875

1. Indications

The ischemic limb exercise test is indicated for patients presenting with symptoms that may suggest underlying metabolic disorders affecting muscle function. These indications include:

• Muscle Weakness - Patients experiencing unexplained weakness in the muscles, particularly in the limbs, may benefit from this test to identify potential metabolic causes.
• Fatigue - Individuals who report significant fatigue during physical activities, especially those that involve the upper extremities, may have metabolic dysfunctions that this test can help diagnose.
• Cramps - Recurrent muscle cramps during exertion can indicate metabolic issues, and the test can assist in determining if these cramps are due to disorders of glycolysis or other metabolic pathways.

2. Procedure

The ischemic limb exercise test involves several key procedural steps that are critical for accurate assessment of muscle metabolism. These steps include:

• Step 1: Venous Catheter Placement - A venous catheter is carefully inserted into the patient's hand or forearm. This catheter is essential for obtaining blood samples throughout the procedure, allowing for real-time monitoring of metabolic changes.
• Step 2: Baseline Blood Sample Collection - An initial blood sample is drawn through the catheter to establish baseline levels of lactate and ammonia. These baseline measurements are crucial for comparison with post-exercise levels.
• Step 3: Application of Blood Pressure Cuff - A blood pressure cuff is placed on the upper arm and inflated to a pressure above the patient's systolic blood pressure. This inflation induces ischemia in the forearm, which is necessary for the subsequent exercise phase.
• Step 4: Exercise with Hand Grip Dynamometer - The patient is instructed to use a hand grip dynamometer, performing a series of squeezes and releases at a set pace. This exercise continues until the patient experiences muscle fatigue, pain, or cramping, typically lasting at least two minutes.
• Step 5: Deflation of Blood Pressure Cuff - After the exercise is completed, the blood pressure cuff is deflated, restoring blood flow to the forearm and allowing for the collection of post-exercise blood samples.
• Step 6: Serial Blood Specimen Collection - Blood specimens are obtained at prescribed intervals following the exercise to measure lactate and ammonia levels. These measurements provide insight into the metabolic response of the muscles during and after ischemia.

3. Post-Procedure

After the ischemic limb exercise test, patients may be monitored for any immediate post-procedural effects, such as discomfort or changes in muscle function. The collection of serial blood specimens allows healthcare providers to analyze the metabolic changes that occurred during the test. Patients may be advised to rest and hydrate following the procedure, and any abnormal results will be discussed in follow-up appointments to determine the next steps in diagnosis or treatment. It is important for healthcare professionals to document the findings accurately and to consider the implications of the test results in the context of the patient's overall clinical picture.