Table 3.

Details regarding preoperative extradural and extradural catheter placement, drugs used and intraoperative opioid requirement in a cohort of dogs undergoing cholecystectomy.

N of dogs	Tuohy needle	Catheter advancement	Drugs used
	Entrance point	Catheter tip level	0.5% L-bupivacaine (mg/kg)	1% Morphine (mg/kg)	0.03% Buprenorphine (μg/kg)	Total volume (ml/kg)	L-bupivacaine final concentration (%)	Intraoperative opioid administered
1	T13-L1	T10-T11	0.59	0.12		0.12	0.48	Fentanyl boluses
1	L2-L3	T13-L1	0.81		9.8	0.20	0.42	No
1	L6-L7	L2-L3	1.62	0.13		0.34	0.47	No
5	L7-S1	L1-L2	0.57		5.7	0.14	0.4	Alfentanil CRI
		L1-L2	1.35		8.1	0.54	0.25	No
		L2-L3	1.28	0.09		0.27	0.48	No
		L3-L4	0.64	0.09		0.19	0.33	No
		L3-L4	0.99	0.1		0.30	0.33	No
1	L1-L2	N/A	0.99	0.16		0.21	0.46	Alfentanil CRI
2	L6-L7	N/A	1.26 1.29	0.12 0.19		0.38 0.32	0.33 0.36	No
1	L6-L7	N/A	1.48		9.9	0.42	0.35	No
5	L7-S1	N/A	1.27 (0.67–2.1)*	0.1 (0.1–0.17)*		0.32 (0.18–0.47)*	0.44 (0.33–0.48)*	Fentanyl boluses in three dogs
5	L7-S1	N/A	1.98 (1.6–2.1)*		9.5 (9.4–10.3)*	0.64 (0.4–1.1)*	0.45 (0.19–0.46)*	Fentanyl boluses in three dogs

^*indicates median (95%CI).

n, number; T, thoracic; L, lumbar; S, sacral; CRI, constant rate infusion; N/A, not applicable: the drug was injected at the entrance point and no extradural catheter was placed preoperatively.