Greater Cephalad Extent of Thoracic Epidural Sensory Anesthesia After Lidocaine and Epinephrine Test Dose Correlates With Analgesic Consumption and Pain Burden After Uterine Fibroid Artery Embolization

BACKGROUND AND OBJECTIVES: Ischemic pain after uterine fibroid artery embolization (UFAE) is often severe. We evaluated the sensory anesthesia extent from thoracic epidural catheter test injection of lidocaine 75 mg with epinephrine 25 μg as a predictor of analgesia effectiveness after UFAE. METHODS: One hundred patients were studied. Pinprick and cold insensitivity were assessed from L3 to T4 at 5-minute intervals for 30 minutes after the test dose. Thoracic epidural management was standardized. Total epidural infusate and numeric rating of pain (0-10) scores were recorded. RESULTS: Pinprick or cold insensitivity at T9 to T10 dermatome was present in 94% of patients. Forty-six subjects (45%) achieved a sensory level at or above the T6 dermatome at 30 minutes. Median analgesic consumption in the first hour and at catheter discontinuation was greater in subjects with a sensory level above T6 compared with those below T6: first hour difference, 7 mL (95% confidence interval [95% CI], 0-12 mL; P = 0.02); difference at discontinuation, 21 mL (95% CI, 4-35 mL; P = 0.02). The area under the pain score by time curve for the first 24 hours was greater in patients with sensory levels above T6: difference 32 score · hour (95% CI, 12 score · h - 60 score · h; P = 0.001). CONCLUSIONS: Sensory anesthesia spread above the T6 dermatome 30 minutes after a test dose of 1.5% lidocaine was an independent predictor of the analgesic consumption after UFAE. Pain burden and oral opioid consumption were also increased in subjects who demonstrated a high sensory spread after the test dose.