Local infiltration for postsurgical analgesia following total hip arthroplasty: a comparison of liposomal bupivacaine to traditional bupivacaine

Figures & data

Table 1. Patient demographics.

Variable	Liposomal Bupivacaine n = 64	Control n = 66	All Patients N = 130	p Value
Age, mean (SD), years	67 (10)	71 (11)	69 (11)	.051
≤65, n (%)	25 (39)	19 (29)	44 (34)
>65, n (%)	39 (61)	47 (71)	86 (66)
Gender, n (%)				.052
Male	39 (61)	29 (44)	68 (52)
Female	25 (39)	37 (56)	62 (48)
Race, n (%)				1.000
White	64 (100)	65 (98)	129 (99)
Other	0	1 (2)	1 (1)
BMI, mean (SD), kg/m^2	29.9 (5.5)	30.4 (6.9)	30.2 (6.3)	.634
<25, n (%)	10 (16)	14 (21)	24 (18)
25–29.9, n (%)	27 (42)	20 (30)	47 (36)
≥30, n (%)	27 (42)	32 (48)	59 (45)
Procedure side, n (%)				.299
Left	30 (47)	25 (38)	55 (42)
Right	34 (53)	41 (62)	75 (58)
Medical insurance, n (%)				.491
Medicare	31 (48)	28 (42)	59 (45)
Other	33 (52)	38 (58)	71 (55)
Living situation, n (%)				.785
Home alone	18 (28)	20 (30)	38 (29)
Home with family or other	46 (72)	46 (70)	92 (71)

BMI: body mass index; SD: standard deviation.

Table 2. Comorbidities.

Comorbidity, n (%)	Liposomal Bupivacaine n = 64	Control n = 66	All Patients N = 130	p Value
Hypertension	34 (53)	38 (58)	72 (55)	.610
Depression	6 (9)	13 (20)	19 (15)	.096
Diabetes	9 (14)	6 (9)	15 (12)	.375
Cardiac disease	15 (23)	18 (27)	33 (25)	.615
Cancer	9 (14)	16 (24)	25 (19)	.141
Sleep apnea	7 (11)	8 (12)	15 (12)	.833
Spinal disease	6 (9)	1 (2)	7 (5)	.110
Renal disease	4 (6)	5 (8)	9 (7)	1.000
Gastric disease	9 (14)	4 (6)	13 (10)	.128
Chronic lung disease	7 (11)	4 (6)	11 (9)	.318
Thyroid disease	6 (9)	0	6 (5)	.033
Hypercholesterolemia	7 (11)	16 (24)	23 (18)	.047
Number of comorbidities, n (%)
0	11 (17)	9 (14)	20 (15)	.945
1	16 (25)	16 (24)	32 (25)
2	17 (27)	19 (29)	36 (28)
3 or more	20 (31)	22 (33)	42 (32)

Figure 1. Mean distance walked after surgery. *Unadjusted p = .025, adjusted p = .070. Day of surgery: liposomal bupivacaine, n = 62; control, n = 66. POD 1: liposomal bupivacaine, n = 55; control, n = 56. POD 2: liposomal bupivacaine, n = 32; control, n = 32. Day of discharge: liposomal bupivacaine, n = 54; control, n = 41. POD: postoperative day; SD: standard deviation.

Figure 2. Proportion of patients using opioid rescue. *Unadjusted and adjusted p < .01. Day of surgery: liposomal bupivacaine, n = 32; control, n = 38. POD 1: liposomal bupivacaine, n = 19; control, n = 37. POD 2: liposomal bupivacaine, n = 5; control, n = 20. POD: postoperative day.

Figure 3. Mean cumulative AUC of the numeric pain score. *Unadjusted and adjusted p < .01. Day of surgery: liposomal bupivacaine, n = 62; control, n = 55. POD 1: liposomal bupivacaine, n = 61; control, n = 62. POD 2: liposomal bupivacaine, n = 35; control, n = 51. AUC: area under the curve; POD: postoperative day; SD: standard deviation.

Table 3. Adjusted hospital charges and cost.

Variable	Liposomal Bupivacaine n = 24^e Adjusted Mean (95% CI)	Control n = 66 Adjusted Mean (95% CI)	Unadjusted p Value	Adjusted p Value^d
Room and board^f	$4355 (3813–4896)	$5443 (5043–5843)	.007	.002
Pharmacy^g	$3324 (2915–3734)	$3249 (3016–3483)	.592	.762
Medical/surgical supplies^h	$16,552 (15,055–18,049)	$21,819 (20,659–22,979)	<.001	<.001
Diagnostic/laboratory testing/OR^i	$12,595 (11,452–13,738)	$14,527 (13,752–15,303)	.007	.008
PT/OT/ST^b	$1985 (1673–2298)	$2619 (2373–2865)	.013	.002
Other	$662 (505–819)	$815 (702–928)	.182	.128
Total charges	$43,794 (41,905–45,683)	$48,010 (46,804–49,215)	<.001	<.001
Total cost^c	$9984 (9953–10,415)	$10,949 (10,674–11,225)	<.001	<.001

CI: confidence interval; CMS: Centers for Medicare & Medicaid Services; OR: operating room; OT: occupational therapy; PT: physical therapy; ST: speech therapy.

^a All charges were inflated to 2015 US dollars using the Hospital Service Consumer Price Index.

^b PT charge + PT evaluation + OT charge + OT evaluation.

^c Total cost was converted from total charges based on CMS cost-to-charge ratio (CCR).

^d Analyzed using a generalized linear model with log link and gamma distribution adjusted by age, sex, insurance type, living situation, body mass index, procedure side, and comorbidity.

^e Detailed charge information was available for 24 patients.

^f Bed charge + recovery charge; ^gpharmacy charge + drug charge.

^h Medical supplies + sterile/nonsterile supplies + implants + anesthesia.

ⁱ Vascular lab + labs + X-ray + pathology + OR services.