Procedural Pain During Lumbar Medial Branch Blocks With and Without Skin Wheal Anesthesia: A Prospective Comparative Observational Study

Abstract

Objective: To determine if skin wheals reduce procedural pain associated with lumbar medial branch blocks (MBBs) performed with 25-gauge needles.

Design: Prospective comparative observational study.

Setting: Outpatient Physical Medicine & Rehabilitation and interventional pain practice within an academic tertiary care center.

Subjects: Ninety-nine consecutive patients who underwent lumbar MBBs for facet pain were included. Patients who were obese or required larger-diameter needles were excluded.

Methods: One to three facet joints were targeted per side, with some patients receiving bilateral procedures. All injections were performed with 25-gauge, 3.5-inch Quincke tip needles under fluoroscopic guidance. A total of 306 needle sticks were recorded. MBBs were performed without skin wheals or any other type of local anesthesia (35 patients, 108 needle sticks), with skin wheals (30 patients, 94 needle sticks), and in mixed groups (34 patients, 47 needle sticks with skin wheals, 57 needle sticks without skin wheals or other type of local anesthesia). Patients rated the pain of each needle placement immediately after the multilevel MBB procedure.

Results: Considering all 306 needle sticks, needles that were placed using skin wheals caused slightly more pain than those placed without skin wheals or any other type of local anesthesia (P = 0.007).

Conclusions: Skin wheals do not reduce and may increase procedural pain associated with lumbar MBBs performed with 25-gauge needles.

Keywords: Anesthesia; Blocks; Local; Medial; Pain; Skin.