How to minimize the pain of local anesthetic administration
Expertise in the delivery of effective local analgesia is critical to the success of in-office procedures. Here’s how to optimize patient outcomes and satisfaction.
PRACTICE RECOMMENDATIONS
› Add epinephrine and sodium bicarbonate buffer to local anesthetic solution to reduce pain and procedural blood loss. A
› Use such techniques as counter-stimulation, a perpendicular angle of injection, a subcutaneous depth of injection, and a slow rate of injection to minimize patient discomfort. A
Strength of recommendation (SOR)
A Good-quality patient-oriented evidence
B Inconsistent or limited-quality patient-oriented evidence
C Consensus, usual practice, opinion, disease-oriented evidence, case series
Speed of injection. Rapid injection of anesthesia is associated with worse injection site pain and decreased patient satisfaction.48-50 Slowing the rate of injection causes less rapid distention of the dermis and subcutaneous space, resulting in decreased pain afferent activation and increased time for nerve blockade. Its importance is underscored by a prospective, randomized trial that compared rate of administration with buffering of local anesthetics and demonstrated that slow administration impacted patient-perceived pain more than buffering solution.51
Needle stabilization. Following perpendicular entry of the needle into the area of planned infiltration, deliver 0.5 mL of local anesthetic into the subcutaneous space without movement of the needle tip.52 With a stabilized needle tip, pain associated with initial needle entry is no longer perceived within 15 to 30 seconds.
It is paramount to stabilize both the syringe and the area of infiltration to prevent patient movement from causing iatrogenic injury or the need for multiple needlesticks. This can be accomplished by maintaining the dominant hand in a position to inject (ie, thumb on the plunger).
Needle reinsertion. Once subcutaneous swelling of local anesthesia is obtained, the needle may be slowly advanced, maintaining a palpable subcutaneous wavefront of local anesthesia ahead of the needle tip as it moves proximally to distally.2,52 Any reinsertion of the needle should be through previously anesthetized skin; this blockade is assessed by the presence of palpable tumescence and blanching (from the epinephrine effect).53
An example of the application of these injection pearls is demonstrated in the administration of a digital nerve block in FIGURE 2.54,55 With the use of the techniques outlined here, the patient ideally experiences only the initial needle entry and is comfortable for the remainder of the procedure.
CORRESPONDENCE
Katharine C. DeGeorge, MD, MS, Department of Family Medicine, University of Virginia, 1215 Lee Street, Charlottesville, VA, 22903; kd6fp@viginia.edu.
