Surgical Site Infection Following Neuromuscular Posterior Spinal Fusion Fell 72% After Adopting the 2013 Best Practice Guidelines

Stephen R. Stephan, MD; Kenneth D. Illingworth, MD; Kavish Gupta, MD; Lindsay M. Andras, MD; David L. Skaggs, MD, MMM

Spine. 2021;46(17):1147-1153.

Abstract and Introduction

Abstract

Study Design: Retrospective cohort study.

Objective: The purpose of this study is to investigate the incidence of surgical site infection in neuromuscular scoliosis (NMS) patients at a tertiary children's hospital before and after the implementation of strategies mentioned in the 2013 Best Practice Guideline.

Summary of Background Data: Patients with NMS are at high risk for surgical site infection following spine surgery. In 2013, a Best Practice Guideline for surgical site infection prevention in high-risk pediatric spine surgery patients reported strategies to decrease incidence. To date, no studies have looked at the efficacy of these strategies.

Methods: A retrospective review of surgical site infection in NMS patients was performed. NMS patients undergoing primary posterior spinal fusion from January 2008 to December 2012 (Group 1) and January 2014 to December 2018 (Group 2) were included, with 2013 excluded as a transition year. The primary outcome was incidence of surgical site infection within 1 year of surgery, as defined by the Centers for Disease Control and National Healthcare Safety Network. All patients had at least 1 year of documented follow-up.

Results: One hundred ninety eight patients were included, 62 in Group 1 and 136 in Group 2. Age, BMI, sex, fusion to pelvis, preoperative Cobb angle, incontinence, drain use, blood loss, surgical time, and other perioperative values were similar (P > 0.05). Deep surgical site infection occurred in 10 (16.1%) patients in Group 1 and six (4.4%) patients in Group 2 (P = 0.005). Thirteen (59.1%) identified organisms were gram-negative, with 11 (84.6%) isolated from Group 1 (P = 0.047). Polymicrobial infections accounted for six (37.5%) infections overall.

Conclusion: The incidence of surgical site infection in NMS patients decreased significantly (16.1% vs. 4.4%) after the implementation of the strategies mentioned in the 2013 Best Practice Guideline. Further studies are required to continue to decrease the incidence in this high-risk population.

Level of Evidence: 3

Introduction

Pediatric patients undergoing posterior spinal fusion with instrumentation (PSF) for scoliosis are at risk for infections. Infections lead to prolonged hospital stays, reoperations and readmissions, revision surgery, increased healthcare costs, and emotional distress.^[1–4] Numerous studies have demonstrated infection rates for primary PSF to range from 1% to almost 40%,^[5–12] depending on the underlying etiology of scoliosis.

Surgical site infections have been shown to be more common in children with non-idiopathic etiologies, particularly neuromuscular scoliosis (NMS). Studies have reported infection rates as high as 24%.^{[4,9,11,13–16]} These children commonly have severe scoliosis, which necessitate larger exposures, increased blood loss, and longer surgical times,^[2,5,17] with a limited ability to cope with surgical stress. Risk factors include inadequate prophylactic antibiotic dosing, fusion to pelvis, preoperative malnutrition, and neurologic function.^{[4,5,12,18–20]} This high-risk population was the focus of a Best Practice Guideline (BPG) in 2013 by Vitale et al,^[21] where a consensus to support 14 perioperative strategies to prevent surgical site infections was reached.

The purpose of this study is to investigate the efficacy of the strategies mentioned in the BPG in NMS patients undergoing primary PSF. Our primary outcome was incidence of deep surgical site infection requiring surgical intervention within 1 year of surgery, comparing the 4 years before and after the implementation of the BPG strategies.

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Abstract and Introduction
Methods
Results
Discussion
References
Sidebar

Table 1. Strategies Mentioned in 2013 Best Practice Guideline
1. Chlorhexidine skin wash was done at home the night before surgery
2. Preoperative urine cultures obtained and treated if positive
3. Patient family given a preoperative patient education sheet
4. Preoperative nutritional assessment completed
5. Clipping preferred to shaving in operating room, if removing hair
6. Perioperative intravenous cefazolin administered
7. Perioperative intravenous prophylaxis for gram-negative bacilli administered
8. Adherence to perioperative antimicrobial regimens was monitored
9. Operating room access was limited during scoliosis surgery
10. Ultraviolet lights were not used in the operating room
11. Patients received intraoperative wound irrigation
12. Vancomycin powder was used in the bone graft and/or surgical site
13. Impervious dressings were used postoperatively
14. Postoperative dressing changes were minimized before discharge

Table 2. Demographics, Patient Characteristics, and Preoperative Data
Variable	Group 1 2008–2012 n = 62	Group 2 2014–2018 n = 136	P Value^†
Age, yrs	14.2 ± 2.3	13.7 ± 2.5	0.209
Sex			0.327
Female	25 (40.3%)	65 (47.8%)
Male	37 (59.7%)	71 (52.2%)
Body mass index	18.7 ± 5.6	18.3 ± 3.9	0.537
Preoperative Cobb angle, °	87.2 ± 31.5	81.6 ± 22.7	0.159
Preoperative incontinence			0.987
Yes	51 (82.3%)	112 (82.4%)
No	11 (17.7%)	24 (17.6%)
Etiology of scoliosis			0.001
Cerebral palsy (CP)	25 (40.3%)	77 (56.6%)
Muscular dystrophy	17 (27.4%)	14 (10.3%)
Spina bifida	3 (4.8%)	2 (1.5%)
Syndromic	6 (9.7%)	27 (19.9%)
Spinal muscular atrophy	2 (3.2%)	8 (5.9%)
Other	9 (14.5%)	8 (5.9%)
GMFCS level (if has CP)			0.608
1	0 (0%)	0 (0%)
2	1 (4.0%)	7 (9.2%)
3	0 (0%)	5 (6.6%)
4	4 (16.0%)	10 (13.2%)
5	20 (80.0%)	54 (71.1%)
Tracheostomy present			0.702
Yes	8 (12.9%)	15 (11%)
No	54 (91.9%)	121 (88.9%)
Gastrostomy tube			0.004
Yes	22 (35.5%)	78 (57.4%)
No	40 (64.5%)	58 (42.6%)
Use of non-invasive ventilation			0.727
Yes	11 (17.7%)	27 (19.9%)
No	51 (82.2%)	109 (80.1%)

^† P values correspond to the Student t test or chi-square test.
Note: GMFCS indicates Gross Motor Function Classification System.

Table 3. Operative Data
Variable	Group 1 2008–2012 n = 62	Group 2 2014–2018 n = 136	P Value^†
Preoperative hematocrit	41.1 ± 4.5	40.3 ± 6.1	0.325
Postoperative hematocrit	30.4 ± 4.4	29.8 ± 6.9	0.562
Estimated blood loss, cm³	914.7 ± 523.4	778.5 ± 484.2	0.0763
Implant material			<0.001
Cobalt chrome	8 (12.9%)	100 (73.5%)
Titanium	4 (6.5%)	5 (3.7%)
Stainless steel	43 (69.4%)	0 (0%)
Hybrid	0 (0%)	3 (2.2%)
Unknown	7 (11.3%)	28 (20.6%)
Length of fusion (vertebrae)	15.2 ± 1.9	15.4 ± 1.3	0.368
Instrumentation to pelvis			0.613
Yes	52 (83.9%)	110 (80.9%)
No	10 (16.1%)	26 (19.1%)
Intraoperative blood transfusion			0.126
Yes	34 (54.8%)	90 (66.2%)
No	28 (45.2%)	46 (33.8%)
Drain placed intraoperatively			0.241
Yes	61 (98.4%)	129 (94.9%)
No	1 (1.6%)	7 (5.1%)
Surgical time, min	346.3 ± 128.2	360.7 ± 102.9	0.8457
Presence of dual attendings in case			0.855
Yes	11 (17.7%)	23 (16.9%)
No	51 (82.3%)	113 (83.1%)

†P values correspond to the Student t test or chi-square test.

Table 4. Best Practice Guideline Strategies Implementation by Group
Variable	Group 1 2008–2012 n = 62	Group 2 2014–2018 n = 136	P Value^†
Preoperative nutrition consult			0.002
Yes	15 (24.2%)	64 (47.1%)
No	47 (75.8%)	72 (52.9%)
Perioperative IV ancef			1
Yes	62 (100%)	136 (100%)
No	0 (0%)	0 (0%)
Perioperative IV gram-negative antibiotic			<0.001
Yes	53 (85.5%)	136 (100%)
No	9 (14.55)	0 (0%)
Vancomycin* in bone graft and/or surgical site			<0.001
Yes	13 (21%)	132 (97.1%)
No	49 (79%)	4 (2.9%)

Note: Nutrition consult within 12 months prior to surgery.
*Or Tobramycin.
†P values correspond to the chi-square test.

Table 5. Surgical Site Infection Data
Variable	Group 1 2008–2012	Group 2 2014–2018	P Value^†
Surgical site infection	10 (16.1%)	6 (4.4%)	0.005
Gram-negative organisms isolated	11 (73.3%)	2 (28.5%)	0.047
Gram-positive organisms isolated	4 (26.7%)	3 (42.9%)	0.447
Polymicrobial infections	5 (50%)	1 (16.7%)	0.182
Time to infection, days	41.5 ± 32.9	115.7 ± 150.9	0.1468

^† P values correspond to the Student t test or chi-square test.

Table 6. Organisms Isolated
Organism	Gram Stain	Group 1 2008–2012	Group 2 2014–2018
Pseudomonas aeruginosa	Gram-negative	3
Pseudomonas stutzeri	Gram-negative	1
Campylobacter jejuni	Gram-negative	1
Klebsiella pneumoniae	Gram-negative	1
Escherichia coli	Gram-negative	4	1
Enterococcus faecalis	Gram-positive	1
Methicillin Resistant Staphylococcus aureus	Gram-positive	2
Methicillin Sensitive Staphylococcus aureus	Gram-positive	1
Enterobacter cloacae	Gram-negative	1
Propionibacterium acnes	Gram-positive		1
Cornyebacterium amycolatum	Gram-positive		1
Proteus mirabilis	Gram-negative		1
Staphylococcus lugdunensis	Gram-positive		1
No organism identified	Not applicable		2