Intrathecal morphine vs femoral nerve block for postoperative-analgesia after total knee arthroplasty: A two-year retrospective analysis

Table 1 Demographic data

	ITM (n = 22)	FNB (n = 32)	Statistical significance
Median (IQR) age: Years	69.0 (62.8-74.3)	61.0 (57.0-67)	P = 0.002
Sex: Numbers
Male	9 (37.5%)	15 (62.5%)	P = 0.665
Female	13 (43.3%)	17 (56.7%)
Median (IQR) weight: Kg	64.3 (53.2-77.2)	67.3 (61.2-80.2)	P = 0.275
Median (IQR) ASA status	3.0 (2.0-3.0)	2.0 (2.0-3.0)	P = 0.161
Median (IQR) total surgery time in minutes	117.5 (108.8-135.0)	107.5 (86.3-128.8)	P = 0.163

IQR: Interquantile range; n: Numbers; ITM: Intrathecal morphine; FNB: Femoral nerve block.

Table 2 Results

	ITM (n = 22)	FNB (n = 32)
Ease of performance	Very easy, no special training	Expertise and training required, special equipment required
Added cost	Only morphine	Ultrasound machine, special needle and local anesthetic
Median (IQR) pain score at:	Low	High
6 h	0.0 (0.0-0.0)	2.0 (2.0-4.8)
12 h	0.0 (0.0-0.0)	2.0 (2.0-3.8)
24 h	0.0 (0.0-0.3)	2.0 (2.0-4.0)
Median (IQR) of morphine requirement (in mg) in 24 h	Low 5.0 (3.8-10.0)	High 16.5 (8.0-21.5)
Median (IQR) of NSAID unit in 24 h	2.0 (1.0-2.0)	1.0 (0.0-1.3)
Median (IQR) of Paracetamol (G) in 24 h	3.0 (2.0-3.0)	3.0 (2.0-4.0)
Complications	Low	Low
	No PONV since antiemetic prescribed in anticipation	Incidence of PONV was higher since no regular antiemetic given (16 at 6 h, 11 at 12 h and 9 at 24 h)
	No urinary retention since all patients were catheterized	No urine retention
	No respiratory depression	No respiratory depression
	No itching recorded	No itching recorded
Number of elective HDU admission status	3 (15%)	2 (6.5%)
Median (IQR) days to discharge	4.5 (3.0-5.0)	4.0 (3.0-6.0)
Patient satisfaction	18/20 (90.0%) rated good	4/31 (12.9%) rated good

IQR: Interquantile range; n: Numbers; ITM: Intrathecal morphine; FNB: Femoral nerve block; PONV: Post-operative nausea and vomiting; HDU: High dependency unit.