Table 1. Comparison of dye staining at various spinal levels using 10 ml or 30 ml of injectate for erector spinae plane blocks.

	Volume of dye solution
	10 ml injectate (n = 5)			30 ml injectate (n = 7)
Spinal level	SCTL	Spinal nerves at the intervertebral foramen	Sympathetic nerves-epidural space	SCTL	Spinal nerves at the intervertebral foramen	Sympathetic nerves-epidural space
T2	-	-	-	1/7	-	-
T3	-	-	-	3/7	1/7	-
T4	2/5	-	-	6/7	4/7	-
T5 (injection site)	4/5	-	-	7/7	7/7	1/7
T6	3/5	-	-	7/7	5/7	-
T7	-	-	-	4/7	2/7	-
T8	-	-	-	1/7	-	-

‘-’ indicates no staining. SCTL is the superior costotransverse ligament. Values are the number of stained structures/total number of structures.