Evaluation of an opioid-sparing protocol for spine surgeries performed in an ambulatory surgery center

Table 1 Patient demographics, comorbidities, and surgical details

Demographics/comorbidities	All patients (n = 290)
Age (years)	55.1 ± 13.5
BMI (kg/m2)	28.6 ± 5.1
Gender
Male	158 (54.5)
Female	132 (45.5)
Race
Black	27 (9.3)
White	246 (84.8)
Other	17 (5.9)
CCI score	1.6 ± 1.7
ASA score
1	21 (7.2)
2	193 (66.6)
3	76 (26.2)
Depression/anxiety	131 (45.2)
Chronic opioid use	15 (5.2)
Current smoker	34 (11.7)
Former smoker	80 (27.6)
Surgical details
Surgery type
Anterior cervical fusion	69 (23.8)
Lumbar laminectomy/discectomy	190 (65.5)
Posterior lumbar fusion	31 (10.7)
Operative levels
1	244 (84.1)
2	46 (15.9)

BMI: Body mass index; CCI: Charlson Comorbidity Index; ASA: American Society of Anesthesiologists.

Table 2 Patient demographics, comorbidities and surgical details by protocol, n (%)/mean ± SD

Demographics/comorbidities	Usual care (n = 208)	Opioid-sparing protocol (n = 82)	P value
Age (years)	55.6 ± 13.5	54.0 ± 13.4	0.358
BMI (kg/m2)	28.8 ± 4.9	28.3 ± 5.5	0.524
Gender			0.569
Male	92 (44.2)	42 (51.2)
Female	116 (55.8)	40 (48.8)
Race			0.8541
Black	21 (10.1)	6 (7.3)
White	175 (84.1)	71 (86.6)
Other	12 (5.8)	5 (6.1)
CCI score2	1.0 (0.0-2.0)	1.0 (0.0-2.0)	0.562
ASA score			0.169
1	12 (5.8)	9 (11.0)
2	137 (65.9)	56 (68.3)
3	59 (28.4)	17 (20.7)
Depression/anxiety	90 (43.3)	41 (50.0)	0.365
Chronic opioid use	8 (3.8)	7 (8.5)	0.1381
Current smoker	21 (10.1)	13 (15.9)	0.242
Former smoker	63 (30.3)	17 (20.7)	0.135
Surgical details
Surgery type
Anterior cervical fusion	49 (23.6)	20 (24.4)	1
Lumbar laminectomy/discectomy	131 (63.0)	59 (72.0)	0.190
Posterior lumbar fusion	28 (13.5)	3 (3.7)	0.0191
Operative levels			0.856
1	174 (83.7)	70 (85.4)
2	34 (16.3)	12 (14.6)

¹Denotes Fisher’s Exact test.

²Non-normally distributed data presented as median (25^th-75^th percentile), Mann Whitney U test.

BMI: Body mass index; CCI: Charlson Comorbidity Index; ASA: American Society of Anesthesiologists.

Table 3 Perioperative ambulatory surgery center outcomes by protocol, mean ± SD/median (25^th-75^th percentile)

	Usual care (n = 208)	Opioid-sparing protocol (n = 82)	P value
Intraoperative MME1	30.0 (25.0-45.0)	25.0 (25.0-39.4)	0.119
Minutes in OR	113.4 ± 37.6	106.8 ± 27.8	0.099
PACU hours	2.8 ± 1.5	2.4 ± 1.3	0.006
PACU opioids received, n (%)	147 (70.7)	45 (54.9)	0.015
PACU MME1	5.0 (0.0-12.5)	5.0 (0.0-5.0)	< 0.001
LOS hours	4.9 ± 1.9	4.1 ± 1.7	< 0.001

¹Non-normally distributed data presented as median (25^th-75^th percentile), Mann Whitney U test.

MME: Morphine milligram equivalents; OR: Operating room; PACU: Post-anesthesia care unit; LOS: Length of stay.

Table 4 Postoperative pain management medications by protocol, n (%)

	Usual care (n = 208)	Opioid-sparing protocol (n = 82)	P value
Postoperative multimodal agents prescribed
Diazepam	4 (1.9)	70 (85.4)	< 0.001
Cyclobenzaprine	52 (25.0)	3 (3.7)	< 0.001
Gabapentin or pregabalin	96 (46.2)	66 (80.5)	< 0.001
Acetaminophen	28 (13.5)	60 (73.2)	< 0.001
Postoperative NSAIDs prescribed
Ketorolac	19 (9.1)	69 (84.1)	< 0.001
Ibuprofen	34 (16.3)	16 (19.5)	0.683
Other NSAID	23 (11.1)	61 (74.4)	< 0.001
Postoperative opioids prescribed
Tramadol	9 (4.3)	69 (84.1)	< 0.001
Hydrocodone-acetaminophen	122 (58.7)	-	N/A
Oxycodone-acetaminophen	60 (28.8)	-	N/A
Other opioid	15 (7.2)	-	N/A
Postoperative MME1	140.0 (105.0-210.0)	30.0 (30.0-30.0)	< 0.001

¹Non-normally distributed data presented as median (25^th-75^th percentile), Mann Whitney U test.

NSAID: Non-steroidal anti-inflammatory drug; MME: Morphine milligram equivalents.

Table 5 30-day postoperative outcomes by protocol, n (%)

	Usual care (n = 208)	Opioid-sparing protocol (n = 82)	P value
Call back for pain	66 (31.7)	20 (24.4)	0.276
ED return	24 (11.5)	5 (6.1)	0.197
Readmission	9 (4.3)	3 (3.7)	1
ED return/readmission for pain	8 (3.8)	2 (2.4)	0.730
Additional opioids prescribed	32 (15.4)	6 (7.3)	0.101

ED: Emergency department.

Table 6 Subgroup analysis of anterior cervical discectomy and fusion perioperative and 30-day outcomes, n (%)/mean ± SD/median (25^th-75^th percentile)

	Usual care (n = 49)	Opioid-sparing protocol (n = 20)	P value
Perioperative ASC outcomes
Intraoperative MME1	35.0 (25.0-50.0)	27.5 (25.0-46.3)	0.466
Minutes in OR	116.6 ± 19.8	116.3 ± 17.4	0.955
PACU opioids	44 (89.8)	13 (6.0)	0.034
PACU MME1	7.5 (5.0-15.0)	5.0 (0.0-11.6)	0.076
LOS hours	6.7 ± 1.0	6.3 ± 0.8	0.040
Postoperative MME1	140.0 (140.0-210.0)	30.0 (30.0-30.0)	< 0.001
30-day postoperative outcomes
Call back for pain	12 (24.5)	6 (30.0)	0.864
ED return	8 (16.3)	2 (10.0)	0.7122
Readmission	1 (2.0)	0 (0)	12
ED return/readmission for pain	2 (4.1)	0 (0)	12
Additional opioids prescribed	8 (16.3)	2 (10.0)	0.7122

¹Non-normally distributed data presented as median (25^th-75^th percentile), Mann Whitney U test.

²Denotes Fisher’s Exact test.

ASC: Ambulatory surgery center; MME: Morphine milligram equivalents; OR: Operating room; PACU: Post-anesthesia care unit; LOS: Length of stay; ED: Emergency department.

Table 7 Subgroup analysis of lumbar laminectomy/discectomy perioperative and 30-day outcomes, n (%)/mean ± SD/median (25^th-75^th percentile)

	Usual care (n = 131)	Opioid-sparing protocol (n = 59)	P value
Perioperative ASC outcomes
Intraoperative MME1	25.0 (25.0-37.5)	25.0 (25.0-34.0)	0.259
Minutes in OR	96.2 ± 19.6	99.3 ± 22.9	0.375
PACU opioids	80 (61.1)	29 (49.2)	0.168
PACU MME1	5.0 (0.0-10.0)	0.0 (0.0-5.0)	0.002
LOS hours	3.8 ± 1.3	3.3 ± 1.2	0.005
Postoperative MME1	140.0 (105.0-150.0)	30.0 (30.0-50.0)	< 0.001
30-day postoperative outcomes
Call back for pain	42 (32.1)	13 (22.0)	0.216
ED return	10 (7.6)	3 (5.1)	0.7582
Readmission	5 (3.8)	3 (5.1)	0.7052
ED return/readmission for pain	5 (3.8)	2 (3.4)	12
Additional opioids prescribed	13 (9.9)	4 (6.8)	0.5912

¹Non-normally distributed data presented as median (25^th-75^th percentile), Mann Whitney U test.

²Denotes Fisher’s Exact test.

ASC: Ambulatory surgery center; MME: Morphine milligram equivalents; OR: Operating room; PACU: Post-anesthesia care unit; LOS: Length of stay; ED: Emergency department.