Lidocaine is a common local anesthetic often used in shoulder injections. Its primary purpose is to temporarily block nerve signals in the area, thereby providing pain relief. This temporary numbing effect can be used for diagnostic purposes, helping identify the source of pain, or as a therapeutic measure to alleviate discomfort. The medication works by stabilizing the neuronal membrane, which prevents the initiation and conduction of nerve impulses.
Typical Duration of Relief
The numbing effect of a lidocaine injection in the shoulder typically lasts from 30 minutes to a few hours. Immediate pain relief is often noticeable within minutes, due to lidocaine’s rapid action on nerve endings in the injected area.
When lidocaine is administered alone, its pain relief is transient, and discomfort usually returns once the medication is metabolized. Some shoulder injections combine lidocaine with other medications, such as corticosteroids, which offer longer-term anti-inflammatory effects. In these combined injections, lidocaine provides immediate relief while the corticosteroid begins to reduce inflammation over several days.
Factors Influencing Lidocaine’s Effect
Several factors can influence how long a lidocaine injection provides pain relief in the shoulder. The concentration and total volume of lidocaine administered play a significant role; higher concentrations or larger volumes generally lead to a longer duration of action. The specific site of the injection within the shoulder also impacts its longevity.
The specific injection site, such as a joint space, muscle, or around nerves for a nerve block, affects absorption and distribution rates. Individual metabolic rates, or how quickly the body processes the drug, also influence duration. Higher blood flow to the injection site can lead to faster absorption and a shorter anesthetic effect. The addition of vasoconstrictors, like epinephrine, can slow lidocaine absorption by constricting blood vessels, prolonging its numbing action.
After the Lidocaine Wears Off
Once the numbing effect of the lidocaine injection subsides, it is common for the original pain or discomfort to return. The duration of this return can vary, depending on the underlying condition causing the pain. Patients should closely follow any post-injection instructions provided by their healthcare provider, which may include recommendations for activity levels or pain management.
Lidocaine primarily offers temporary symptom relief and does not address the root cause of shoulder pain. Following the injection, healthcare providers may recommend further steps, such as physical therapy to improve shoulder function and reduce pain. Follow-up appointments are often scheduled to assess the injection’s effectiveness and discuss next diagnostic tests or treatment options.