Ultrasound guided femoral nerve blocks as a compulsory pain protocol in femoral neck fractures

Table 1 Demographic and clinical characteristics

Characteristic	Overall (n = 1577)	Standard analgesia protoco (n = 1190)	US guided femoral nerve block (n = 387)	P value1
Age (years), mean (SD)	76 (15)	75 (15)	80 (11)	< 0.001
Gender, n/N (%)				0.7
Female	1016/1577 (64)	770/1190 (65)	246/387 (64)
Male	561/1577 (36)	420/1190 (35)	141/387 (36)
ASA score, n/N (%)				0.6
1	38/1045 (3.6)	32/776 (4.1)	6/269 (2.2)
2	579/1045 (55)	427/776 (55)	152/269 (57)
3	377/1045 (36)	279/776 (36)	98/269 (36)
4	51/1045 (4.9)	38/776 (4.9)	13/269 (4.8)
Unknown	532	414	118
BMI, mean (SD)	25.5 (4.7)	25.5 (4.7)	25.5 (4.7)	0.8
CVA, n/N (%)	21/1577 (1.3)	17/1190 (1.4)	4/387 (1.0)	0.7
T2DM, n/N (%)	343/1577 (22)	250/1190 (21)	93/387 (24)	0.2
IHD, n/N (%)	315/1577 (20)	244/1190 (21)	71/387 (18)	0.4
Intra capsular fracture, n/N (%)	9/1577 (0.6)	7/1190 (0.6)	2/387 (0.5)	> 0.9
Extra capsular fracture, n/N (%)	220/1577 (14)	154/1190 (13)	66/387 (17)	0.052
Time to surgery (hours), mean (SD)	38 (60)	39 (68)	32 (22)	0.0218
Hospitalization days (days), mean (SD)	15 (14)	15 (14)	16 (13)	0.3

¹Statistical tests performed: Wilcoxon rank-sum test; χ² test of independence; Fisher's exact test.

CVA: Cerebrovascular accident; BMI: Body mass index; T2DM: Type 2 diabetes mellitus; US: Ultrasound; IHD: Ischemic heart disease.

Table 2 The difference in outcomes between ultrasound guided femoral nerve block and standard analgesia protocol

Characteristic	Overall (n = 1577)	Standard analgesia protoco (n = 1190)	US guided femoral nerve block (n = 387)	P value1
Pre surgery VAS score, mean (SD)	1.73 (2.57)	1.82 (2.59)	1.46 (2.49)	0.001
12 hours post-surgery VAS score, mean (SD)	0.70 (1.61)	0.68 (1.57)	0.75 (1.73)	0.3
24 hours post surgery VAS score, mean (SD)	0.81 (1.60)	0.81 (1.55)	0.83 (1.74)	0.058
Stroke, n/N (%)	235/1577 (15)	184/1190 (15)	51/387 (13)	0.3
Sepsis, n/N (%)	19/1577 (1.2)	16/1190 (1.3)	3/387 (0.8)	0.6
Re hospitalization times, mean (SD)	1.35 (2.26)	1.46 (2.34)	0.99 (1.96)	< 0.001
Mortality, n/N (%)	439/1577 (28)	376/1190 (32)	63/387 (16)	< 0.001

¹Statistical tests performed: Wilcoxon rank-sum test; χ² test of independence; Fisher's exact test.

US: Ultrasound; VAS: Visual analogue scale.

Table 3 Association between pre surgery visual analogue scale and ultrasound guided femoral nerve block adjusted for other independent variables

Predictors	Pre-surgery VAS
	Incidence rate ratios	95%CI	P value
US guided femoral nerve block	0.85	0.76-0.95	0.006
Age	0.99	0.99-1.00	< 0.001
ASA score	0.88	0.81-0.95	0.002
Extra capsular fracture	0.82	0.71-0.95	0.007
IHD	1.21	1.07-1.36	0.003

VAS: Visual analogue scale; US: Ultrasound; IHD: Ischemic heart disease.

Table 4 Association between morbidity and all independent variables

Characteristic	Overall (n = 1577)	Non-morbidity group (n = 572)	Morbidity group, (n = 1005)	P value1
US guided femoral nerve block, n/N (%)	387/1577 (25)	174/572 (30)	213/1005 (21)	< 0.001
Age, mean (SD)	76 (15)	72 (17)	79 (13)	< 0.001
Gender, n/N (%)				0.4
Female	1016/1577 (64)	377/572 (66)	639/1005 (64)
Male	561/1577 (36)	195/572 (34)	366/1005 (36)
ASA score, n/N (%)				< 0.001
1	38/1045 (3.6)	27/395 (6.8)	11/650 (1.7)
2	579/1045 (55)	268/395 (68)	311/650 (48)
3	377/1045 (36)	96/395 (24)	281/650 (43)
4	51/1045 (4.9)	4/395 (1.0)	47/650 (7.2)
BMI, mean (SD)	25.5 (4.7)	25.3 (4.4)	25.5 (4.8)	0.5
CVA, n/N (%)	21/1577 (1.3)	3/572 (0.5)	18/1005 (1.8)	0.060
T2DM, n/N (%)	343/1577 (22)	83/572 (15)	260/1005 (26)	< 0.001
IHD, n/N (%)	315/1577 (20)	64/572 (11)	251/1005 (25)	< 0.001
Intra capsular fracture, n/N (%)	9/1577 (0.6)	3/572 (0.5)	6/1005 (0.6)	> 0.9
Extra capsular fracture, n/N (%)	220/1577 (14)	89/572 (16)	131/1005 (13)	0.2
Time to surgery (hours), mean (SD)	38 (60)	36 (73)	39 (52)	0.3
Hospitalization days (days), mean (SD)	15 (14)	13 (11)	16 (14)	< 0.001

¹Statistical tests performed: χ² test of independence; Wilcoxon rank-sum test; Fisher's exact test.

BMI: Body mass index; T2DM: Type 2 diabetes mellitus; US: Ultrasound; IHD: Ischemic heart disease.

Table 5 Association between morbidity and ultrasound guided femoral nerve block adjusted for other independent variables

Predictors	Morbidity
	Odds ratios	95%CI	P value
US guided femoral nerve block	0.52	0.38-0.70	< 0.001
Age	1.02	1.01-1.03	< 0.001
ASA score	2.09	1.64-2.68	< 0.001
T2DM	1.46	1.04-2.06	0.032
IHD	1.57	1.06-2.34	0.026
Hospitalization days	1.02	1.01-1.03	0.002

T2DM: Type 2 diabetes mellitus; US: Ultrasound; IHD: Ischemic heart disease.