y Antibiotic Prophylaxis in Spine Surgery | NASS Clinical Guidelines 1 G o l o Evidence-Based Clinical Guidelines for Multidisciplinary d o h t e Spine Care M e n lI e d uI Antibiotic Prophylaxis in G / n o tI c u Spine Surgery d o r t n I NASS Evidence-Based Clinical Guidelines Committee William O. Shaffer, MD Committee Chair Jamie Baisden, MD Robert Fernand, MD Paul Matz, MD This clinical guideline should not be construed as including all proper methods of care or excluding or other acceptable methods of care reason- ably directed to obtaining the same results. The ultimate judgment regarding any specific procedure or treatment is to be made by the physi- cian and patient in light of all circumstances presented by the patient and the needs and resources particular to the locality or institution. I nt 2 Antibiotic Prophylaxis in Spine Surgery | NASS Clinical Guidelines r o d u c Financial Statement t Io This clinical guideline was developed and funded in its entirety by the North American Spine Society (NASS). All participating n /G authors have disclosed potential conflicts of interest consistent with NASS’ disclosure policy. Disclosures are listed below: u Id Range Key: elIn William O. Shaffer, MD Nothing to disclose. Level A. $100 to $1,000 e Level B. $1,001 to $10,000 M Level C. $10,001 to $25,000 e Paul G. Matz, MD Nothing to disclose. t Level D. $25,001 to $50,000 h o Level E. $50,001 to $100,000 d o Jamie Baisden, MD Nothing to disclose. Level F. $100,001 to $500,000 l o Level G. $500,001 to $1M G y Level H. $1,000,001 to $2.5M Robert Fernand, MD Nothing to disclose. Level I. Greater than $2.5M Comments Comments regarding the guideline may be submitted to the North American Spine Society and will be considered in develop- ment of future revisions of the work. Special Thanks The North American Spine Society would like to express its thanks to Dr. Nikolai Bogduk for generating the calculations in Ap- pendix E to explain the prohibitive nature of the sample sizes required to yield Level I data for the efficacy of antibiotic prophy- laxis. North American Spine Society Clinical Guidelines for Multidisciplinary Spine Care Antibiotic Prophylaxis in Spine Surgery Copyright © 2013 North American Spine Society 7075 Veterans Boulevard Burr Ridge, IL 60527 USA 630.230.3600 www.spine.org ISBN 1-929988-31-1 This clinical guideline should not be construed as including all proper methods of care or excluding or other acceptable methods of care reason- ably directed to obtaining the same results. The ultimate judgment regarding any specific procedure or treatment is to be made by the physi- cian and patient in light of all circumstances presented by the patient and the needs and resources particular to the locality or institution. y Antibiotic Prophylaxis in Spine Surgery | NASS Clinical Guidelines 3 G o l o Table of Contents d o h t e M e n lI e d I. Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 uI G / n II. Guideline Development Methodology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 o tI c u III. Recommendations Regarding Antibiotic Prophylaxis in Spine Surgery . . . . . . . . . . . . . . . . . . . . .8 d o r A. Efficacy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8 t n B. Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20 I C. Redosing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37 D. Discontinuation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40 E. Wound Drains. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44 F. Body Habitus. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46 G. Comorbidities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48 H. Complications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52 IV. Appendices. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 A. Levels of Evidence for Primary Research Questions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55 B. Grades of Recommendations for Summaries or Reviews of Studies. . . . . . . . . . . . . . . . . . . . . . .56 C. Linking Levels of Evidence to Grades of Recommendation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57 D. NASS Literature Search Protocol. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58 E. Comparing the Prevalence of Rare Events. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59 F. Comparing 2007 Recommendations to Current Recommendations . . . . . . . . . . . . . . . . . . . . . .60 V. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66 A technical report, including the literature search parameters and evidentiary tables developed by the au- thors, can be accessed at http://www.spine.org/Documents/Antibiotic_Prophylaxis_TechRept.pdf This clinical guideline should not be construed as including all proper methods of care or excluding or other acceptable methods of care reason- ably directed to obtaining the same results. The ultimate judgment regarding any specific procedure or treatment is to be made by the physi- cian and patient in light of all circumstances presented by the patient and the needs and resources particular to the locality or institution. I nt 4 Antibiotic Prophylaxis in Spine Surgery | NASS Clinical Guidelines r o d u I. Introduction c t Io n / G u Id Objective col. The recommendations made in this guideline are based on e l The objective of the North American Spine Society (NASS) Ev- evidence related to open procedures. No evidence was reviewed In e idence-Based Clinical Guideline on Antibiotic Prophylaxis in related to efficacy and protocol for the use of antibiotic prophy- M Spine Surgery is to provide evidence-based recommendations to laxis in percutaneous procedures. e t address key clinical questions surrounding the use of prophy- h o lactic antibiotics in spine surgery. The guideline is intended to THIS GUIDELINE DOES NOT REPRESENT A “STAN- do address these questions based on the highest quality clinical lit- DARD OF CARE,” nor is it intended as a fixed treatment pro- l o erature available on this subject as of June 2011. The goals of the tocol. It is anticipated that there will be patients who will require G y guideline recommendations are to assist in delivering optimum, less or more treatment than the average. It is also acknowledged efficacious treatment with the goal of preventing surgical infec- that in atypical cases, treatment falling outside this guideline tion. will sometimes be necessary. This guideline should not be seen as prescribing the type, frequency or duration of intervention. Treatment should be based on the individual patient’s need and Scope, Purpose and Intended User doctor’s professional judgment. This document is designed to This document was developed by the North American Spine function as a guideline and should not be used as the sole reason Society Evidence-based Guideline Development Committee as for denial of treatment and services. This guideline is not intend- an educational tool to assist spine surgeons in preventing surgi- ed to expand or restrict a health care provider’s scope of practice cal site infections. This guideline is an update to the 2007 ver- or to supersede applicable ethical standards or provisions of law. sion. The NASS Clinical Guideline on Antibiotic Prophylaxis in Spine Surgery addresses the efficacy and appropriate protocol for Patient Population antibiotic prophylaxis and discusses redosing, discontinuation, wound drains, as well as special considerations related to the po- The patient population for this guideline encompasses adults (18 tential impact of comorbidities on antibiotic prophylaxis proto- years or older) undergoing spine surgery. This clinical guideline should not be construed as including all proper methods of care or excluding or other acceptable methods of care reason- ably directed to obtaining the same results. The ultimate judgment regarding any specific procedure or treatment is to be made by the physi- cian and patient in light of all circumstances presented by the patient and the needs and resources particular to the locality or institution. y Antibiotic Prophylaxis in Spine Surgery | NASS Clinical Guidelines 5 G o l o II. Guideline Development Methodology d o h t e M e n Through objective evaluation of the evidence and transparency cate the strength of the recommendations made in the guideline lI e in the process of making recommendations, it is NASS’ goal to based on the quality of the literature. d uI develop evidence-based clinical practice guidelines for the diag- G nosis and treatment of adult patients with various spinal condi- Grades of Recommendation: /n o tions. These guidelines are developed for educational purposes A: Good evidence (Level I studies with consistent findings) tI to assist practitioners in their clinical decision-making process- c for or against recommending intervention. u es. It is anticipated that where evidence is very strong in support d o of recommendations, these recommendations will be operation- r B: Fair evidence (Level II or III studies with consistent find- t alized into performance measures. n ings) for or against recommending intervention. I Multidisciplinary Collaboration C: Poor quality evidence (Level IV or V studies) for or With the goal of ensuring the best possible care for adult patients against recommending intervention. suffering with spinal disorders, NASS is committed to multidis- ciplinary involvement in the process of guideline and perfor- I: Insufficient or conflicting evidence not allowing a recom- mance measure development. To this end, NASS has ensured mendation for or against intervention. that representatives from medical, interventional and surgical spine specialties have participated in the development and re- Levels of evidence have very specific criteria and are assigned to view of all NASS guidelines. To ensure broad-based representa- studies prior to developing rec-ommendations. Recommenda- tion, NASS has invited and welcomes input from other societies tions are then graded based upon the level of evidence. To better and specialties un-derstand how levels of evidence inform the grades of recom- mendation and the standard nomencla-ture used within the rec- Evidence Analysis Training of All NASS ommendations see Appendix C. Guideline Developers Guideline recommendations are written utilizing a standard NASS has initiated, in conjunction with the University of Al- language that indicates the strength of the recommendation. berta’s Centre for Health Evidence, an online training program “A” recommendations indicate a test or intervention is “recom- geared toward educating guideline developers about evidence mended”; “B” recommendations “suggest” a test or intervention analysis and guideline development. All participants in guide- and “C” recommendations indicate a test or in-tervention “may line development for NASS have completed the training prior be considered” or “is an option.” “I” or “Insufficient Evidence” to participating in the guideline development program at NASS. statements clearly indicate that “there is insufficient evidence to This training includes a series of readings and exercises, or in- make a recommendation for or against” a test or in-tervention. teractivities, to prepare guideline developers for systematically Work group consensus statements clearly state that “in the ab- evaluating literature and developing evidence-based guidelines. sence of reliable evidence, it is the work group’s opinion that” a The online course takes approximately 15-30 hours to complete test or intervention may be appropriate. and participants have been awarded CME credit upon comple- The levels of evidence and grades of recommendation imple- tion of the course. mented in this guideline have also been adopted by the Journal of Bone and Joint Surgery, the American Academy of Orthopae- Disclosure of Potential Conflicts of Interest dic Surgeons, Clinical Orthopaedics and Related Research, the All participants involved in guideline development have dis- journal Spine and the Pediatric Orthopaedic Society of North closed potential conflicts of interest to their colleagues and their America. potential conflicts have been documented in this guideline. Par- In evaluating studies as to levels of evidence for this guide- ticipants have been asked to update their disclosures regularly line, the study design was interpreted as establishing only a po- throughout the guideline development process. tential level of evidence. As an example, a therapeutic study de- signed as a randomized controlled trial would be considered a Levels of Evidence and Grades of Recom- potential Level I study. The study would then be further analyzed as to how well the study design was implemented and significant mendation short comings in the execution of the study would be used to NASS has adopted standardized levels of evidence (Appendix A) downgrade the levels of evidence for the study’s con-clusions. In and grades of recommendation (Appendix B) to assist practitio- the example cited previously, reasons to downgrade the results of ners in easily understanding the strength of the evidence and a potential Level I randomized controlled trial to a Level II study recommendations within the guidelines. The levels of evidence would include, among other possibilities: an under-powered range from Level I (high quality randomized controlled trial) to study (patient sample too small, variance too high), inadequate Level V (expert consensus). Grades of recommendation indi- randomization or masking of the group assignments and lack of validated outcome measures. This clinical guideline should not be construed as including all proper methods of care or excluding or other acceptable methods of care reason- ably directed to obtaining the same results. The ultimate judgment regarding any specific procedure or treatment is to be made by the physi- cian and patient in light of all circumstances presented by the patient and the needs and resources particular to the locality or institution. I nt 6 Antibiotic Prophylaxis in Spine Surgery | NASS Clinical Guidelines r o d u In addition, a number of studies were reviewed several times and (3) represent the current best research evidence available. c t in answering different questions within this guideline. How NASS maintains a search history in Endnote, for future use or Io n a given question was asked might influence how a study was reference. / G evaluated and interpreted as to its level of evidence in answer- u ing that particular question. For example, a randomized control Step 5: Review of Search Results/Identification of Id e trial reviewed to evaluate the differences between the outcomes Literature to Review l In of surgically treated versus untreated patients with lumbar spinal Work group members reviewed all abstracts yielded from the e stenosis might be a well designed and implemented Level I ther- literature search and identified the literature they will review M e apeutic study. This same study, however, might be classified as in order to address the clinical questions, in accordance with t h giving Level II prognostic evidence if the data for the untreated the Literature Search Protocol. Members have identified the o d controls were extracted and evaluated prognostically. best research evidence available to answer the targeted clinical o l questions. That is, if Level I, II and or III literature is available to o G Guideline Development Process answer specific questions, the work group was not required to y review Level IV or V studies. Step 1: Identification of Clinical Questions Trained guideline participants were asked to submit a list of clin- Step 6: Evidence Analysis ical questions that the guideline should address. The lists were Members have independently developed evidentiary tables sum- compiled into a master list, which was then circulated to each marizing study conclusions, identifying strengths and weakness- member with a request that they independently rank the ques- es and assigning levels of evidence. In order to systematically tions in order of importance for consideration in the guideline. control for potential biases, at least two work group members The most highly ranked questions, as determined by the partici- have reviewed each article selected and independently assigned pants, served to focus the guideline. levels of evidence to the literature using the NASS levels of evi- dence. Any discrepancies in scoring have been addressed by two Step 2: Identification of Work Groups or more reviewers. The consensus level (the level upon which Multidisciplinary teams were assigned to work groups and as- two-thirds of reviewers were in agreement) was then assigned signed specific clinical questions to address. Because NASS is to the article. comprised of surgical, medical and interventional specialists, it As a final step in the evidence analysis process, members is imperative to the guideline development process that a cross- have identified and documented gaps in the evidence to educate section of NASS membership is represented on each group. This guideline readers about where evidence is lacking and help guide also helps to ensure that the potential for inadvertent biases in further needed research by NASS and other societies. evaluating the literature and formulating recommendations is minimized. Step 7: Formulation of Evidence-Based Recommendations and Incorporation of Expert Step 3: Identification of Search Terms and Parameters Consensus One of the most crucial elements of evidence analysis to support Work groups held face-to-face meetings to discuss the evidence- development of recommendations for appropriate clinical care based answers to the clinical questions, the grades of recommen- is the comprehensive literature search. Thorough assessment of dations and the incorporation of expert consensus. Expert con- the literature is the basis for the review of existing evidence and sensus has been incorporated only where Level I-IV evidence is the formulation of evidence-based recommendations. In order insufficient and the work group has deemed that a recommenda- to ensure a thorough literature search, NASS has instituted a Lit- tion is warranted. Transparency in the incorporation of consen- erature Search Protocol (Appendix D) which has been followed sus is crucial, and all consensus-based recommendations made to identify literature for evaluation in guideline development. In in this guideline very clearly indicate that Level I-IV evi-dence keeping with the Literature Search Protocol, work group mem- is insufficient to support a recommendation and that the recom- bers have identified appropriate search terms and parameters to mendation is based only on expert consensus. direct the literature search. Specific search strategies, including search terms, parameters Consensus Development Process and databases searched, are documented in the technical report Voting on guideline recommendations was conducted using that accompanies this guideline. a modification of the nominal group technique in which each work group member independently and anonymously ranked Step 4: Completion of the Literature Search a recommendation on a scale ranging from 1 (“extremely inap- Once each work group identified search terms/parameters, the propriate”) to 9 (“extremely appropriate”). Consensus was ob- literature search was implemented by a medical/research librar- tained when at least 80% of work group members ranked the ian, consistent with the Literature Search Protocol. recommendation as 7, 8 or 9. When the 80% threshold was not Following these protocols ensures that NASS recommenda- attained, up to three rounds of discussion and voting were held tions (1) are based on a thorough review of relevant literature; to resolve disagreements. If disagreements were not resolved af- (2) are truly based on a uniform, comprehensive search strategy; ter these rounds, no recommendation was adopted. This clinical guideline should not be construed as including all proper methods of care or excluding or other acceptable methods of care reason- ably directed to obtaining the same results. The ultimate judgment regarding any specific procedure or treatment is to be made by the physi- cian and patient in light of all circumstances presented by the patient and the needs and resources particular to the locality or institution. y Antibiotic Prophylaxis in Spine Surgery | NASS Clinical Guidelines 7 G o l o After the recommendations were established, work group mem- Step 10: Submission for Publication and National d o bers developed the guideline content, addressing the literature Guideline Clearinghouse (NGC) Inclusion h t which supports the recommendations. Following NASS Board approval, the guidelines have been slat- Me ed for publication and submitted for inclusion in the National e Step 8: Submission of the Draft Guidelines for Review/ Guidelines Clearinghouse (NGC). No revisions were made at n lI Comment this point in the process, but comments have been and will be e d Guidelines were submitted to the full Evidence-Based Guideline saved for the next iteration. uI G Development Committee and the Research Council Director for / n review and comment. Revisions to recommendations were con- Step 11: Review and Revision Process o sidered for incorporation only when substantiated by a prepon- The guideline recommendations will be reviewed every three tI c derance of appropriate level evidence. years by an EBM-trained multidisciplinary team and revised as u d appropriate based on a thorough review and assessment of rel- o r Step 9: Submission for Board Approval evant literature published since the development of this version t n Once any evidence-based revisions were incorporated, the drafts of the guideline. I were prepared for NASS Board review and approval. Edits and revisions to recommendations and any other content were con- Nomenclature for Medical/Interventional Treatment sidered for incorporation only when substantiated by a prepon- Throughout the guideline, readers will see that what has tra- derance of appropriate level evidence. ditionally been referred to as “nonoperative,” “nonsurgical” or “conservative” care is now referred to as “medical/interventional care.” The term medical/interventional is meant to encompass pharmacological treatment, physical therapy, exercise therapy, manipulative therapy, modalities, various types of external stim- ulators and injections. This clinical guideline should not be construed as including all proper methods of care or excluding or other acceptable methods of care reason- ably directed to obtaining the same results. The ultimate judgment regarding any specific procedure or treatment is to be made by the physi- cian and patient in light of all circumstances presented by the patient and the needs and resources particular to the locality or institution. 8 Antibiotic Prophylaxis in Spine Surgery | NASS Clinical Guidelines III. Recommendations Regarding Antibiotic Prophylaxis in Spine Surgery A. Efficacy For patients undergoing open spine surgery, does antibiotic prophylaxis result in decreased infection rates compared to patients who do not receive prophylaxis? R e c o P m Preoperative prophylactic antibiotics are suggested to decrease infection R m oP en rates in patients undergoing spine surgery. h d ylax atio Grade of Recommendation: B is n s in R s e P g ine aRd su ing Barker et al1 described a meta-analysis based on a systematic hours prior to surgery) and 71 received placebo. Presence of Rg a review of the literature concerning the efficacy of prophylactic infection was assessed at 30 days, with surgical site infection e n R t antibiotics on the incidence of postoperative spinal infection. defined as drainage of purulent material from the operative y ib io By pooling data from six randomized controlled trials, they site and a positive bacteriological culture, or inflammation of tic found a 2.2% (10 of 451) infection rate if antibiotics were given an area more than 20 mm in diameter; for urinary tract infec- and a 5.9% (23 of 392) infection rate if antibiotics were not tion, more than 100,000 colony forming units/mL on culture; administered. Whereas each of the individual studies did not and for pneumonia, the clinical diagnosis was made by the treat- find a statistical difference, the pooled data did (p<0.01). In ing physician. There were 21 wound or urinary infections in critique of this analysis, the individual studies included in the the 71 patients who received placebo and nine in the 70 who meta-analysis did not show a statistically significant difference received cephazolin (p < 0.05). Nine patients (12.7%) who re- in infection rate with antibiotic use. However, the pooled results ceived placebo and three (4.3%) who received cephazolin devel- did show a significantly lower rate of infection with prophylactic oped wound infections (p = 0.07). All but three of the infections antibiotic use. These data offer Level II therapeutic evidence that in the placebo group were confirmed by bacterial culture. All antibiotics can lead to lower rates of infection for general spine the organisms isolated from the patients who received placebo surgical procedures. (except the group-D streptococci which are inherently resistant) Pavel et al2 reported a prospective, randomized controlled were sensitive to cephazolin whereas in the cephazolin prophy- trial comparing the use of antibiotic prophylaxis with cepha- lactic group 43% of the organisms isolated were resistant or had loridine with a placebo on the rate of postoperative infection in reduced sensitivity to the drug. The authors concluded that the orthopedic surgical procedures. When separately analyzed, the administration of a single dose of cephazolin preoperatively is infection rate after spinal procedures was 9.2% in the placebo recommended for patients undergoing lumbar spinal surgery. group, compared to 3% in the group who received cephalori- In critique, the sample size was small and the study’s follow-up dine. In critique of this study, the numbers were too small in the period was short. In addition, the authors expanded the defini- spine subgroup to detect a statistically significant difference. tion of infection to include wound, urinary tract infection and While this is a Level I study relative to orthopedic procedures, it pneumonia in order to achieve statistical significance. Due to provides Level II therapeutic evidence that the use of periopera- these limitations, this potential Level I study provides Level II tive cephalosporin antibiotic can significantly reduce the rate of therapeutic evidence that for uncomplicated spine surgery, a perioperative infection in the subgroup of patients undergoing single preoperative dose of cephazolin decreases infection rate; orthopedic spinal procedures. however, it does not significantly decrease the rate of wound in- Rubinstein et al3 performed a prospective, randomized fection. The use of cephazolin appears to be associated with an controlled trial to investigate the efficacy of a single dose of 1 increase in development of resistant organisms. g of cephazolin in reducing postoperative infections in patients undergoing ‘clean’ operations on the lumbar spine. Of the 141 patients included in the study, 70 received 1 g intravenous cep- hazolin upon arrival to the operative room (approximately two This clinical guideline should not be construed as including all proper methods of care or excluding or other acceptable methods of care reason- ably directed to obtaining the same results. The ultimate judgment regarding any specific procedure or treatment is to be made by the phy- sician and patient in light of all circumstances presented by the patient and the needs and resources particular to the locality or institution 9 Antibiotic Prophylaxis in Spine Surgery | NASS Clinical Guidelines For a typical, uncomplicated lumbar laminotomy and discectomy, a single preoperative dose of antibiotics is suggested to decrease the risk of infection and/or discitis. Grade of Recommendation: B Petignat et al4 conducted a prospective, randomized controlled sensitive to cephazolin whereas in the cephazolin prophylactic trial assessing the efficacy of one preoperative 1.5 g dose of ce- group 43% of the organisms isolated were resistant or had re- furoxime in preventing surgical site infection after lumbar lami- duced sensitivity to the drug. The authors concluded that the notomy and discectomy for herniated disc. Of the 1237 patients administration of a single dose of cephazolin preoperatively is included in the study, 613 received 1.5 g intravenous cefuroxime recommended for patients undergoing lumbar spinal surgery. on induction and 624 received placebo. Presence of infection, In critique, the sample size was small and the study’s follow-up as defined by the Centers for Disease Control (CDC) guide- period was short. In addition, the authors expanded the defini- c ti lines, was assessed at six weeks, three months and six months. tion of infection to include wound, urinary tract infection and o Baseline characteristics were similar in patients allocated to ce- pneumonia in order to achieve statistical significance. Due to tibi Ry n e furoxime (n = 613) or placebo (n=624). Eight (1.3%) patients these limitations, this potential Level I study provides Level II a g in the cefuroxime group and 18 patients (2.8%) in the placebo therapeutic evidence that for uncomplicated spine surgery, a g uR n s group developed a surgical site infection (p =0.073). A diagno- single preoperative dose of cephazolin decreases infection rate; di sis of spondylodiscitis or epidural abscess was made in nine pa- however, it does not significantly decrease the rate of wound in- gaR Pine tients in the placebo group, but none in the cefuroxime group fection. The use of cephazolin appears to be associated with an e s R (p < 0.01), which corresponded to a number necessary to treat increase in the development of resistant organisms. s in of 69 patients to prevent one of these infections. There were no Rohde et al5 described a retrospective comparative study de- on xis spilganceifibcoa. nOt vaedrvaellr, steh ee vseunrtgsi caatlt rsiibteu tiendfe cttoi oeni trhaetre wceafsu r1o.3x%im we iothr sinig 1n6e4d2 t oco rnespeocrut ttihvee icnacsiedse innc we hoifc pho nsto- oanpteirbaitoivtiec spproonpdhyylloadxiiss cwitaiss ndati Phyla antibiotics versus 2.8% with placebo (p=0.073), and the discitis used and to define the value of a collagenous sponge containing me Ro rate was 0/613 versus 9/624 (p<0.01), respectively. The authors gentamicin in preventing disc space infections. No topical or om P c concluded that a single, preoperative dose of cefuroxime signifi- systemic antibiotics were administered in the first 508 patients. e R cantly reduces the risk of organ-space infection, most notably A 4 cm × 4 cm collagenous sponge containing 8 mg of genta- spondylodiscitis, after surgery for herniated disc. Cefuroxime is micin was placed in the cleared disc space in the sub-sequent protective against spondylodiscitis. This study provides Level I 1134 patients. Surgery was performed for 1584 primary lumbar therapeutic evidence that for uncomplicated lumbar microdis- disc herniations (two-level discectomy in 39 cases, three-level cectomy, a single dose of cefuroxime versus placebo tends to de- discectomy in one case) and 169 operations for recurrent herni- crease rate of post operative infection and significantly reduces ations. In all patients, the erythrocyte sedimentation rate (ESR) the rate of spondylodiscitis specifically. was obtained before surgery and on the first day after surgery. Beginning in January 1992, C-reactive protein (CRP) also was Rubinstein et al3 performed a prospective, randomized con- analyzed before surgery, one day after surgery, and six days after trolled trial to investigate the efficacy of a single dose of 1 g of surgery. All patients were clinically reexamined on days 10-14 cephazolin in reducing postoperative infections in patients un- after surgery (day of discharge). Final follow-up was at 60 days. dergoing ”clean” operations on the lumbar spine. Of the 141 In 19 of these 508 patients, a postoperative spondylodiscitis patients included in the study, 70 received 1 g intravenous cep- developed, accounting for an incidence rate of 3.7%. None of hazolin upon arrival to the operative room (approximately two the 1134 patients receiving antibiotic prophylaxis developed a hours prior to surgery) and 71 received placebo. Presence of postoperative spondylodiscitis during the follow-up period of infection was assessed at 30 days, with surgical site infection de- 60 days. Therefore, the incidence of postoperative spondylodis- fined as drainage of purulent material from the operative site citis was 0%. Using the Fisher exact test, the difference in the and a positive bacteriological culture or inflammation of an area incidence rates between the patient groups with and without more than 20 mm in diameter; for urinary tract infection, more antibiotic prophylaxis during lumbar discectomy was highly sig- than 100,000 colony forming units/mL on culture; and for pneu- nificant (p < 0.00001). The authors observed no complications monia, the clinical diagnosis was made by the treating physician. related to the use of a collagenous sponge containing gentamicin There were 21 wound or urinary infections in the 71 patients for antibiotic prophylaxis. The authors concluded that a 3.7% who received placebo and nine in the 70 who received cephazo- incidence of postoperative spondylodiscitis was found in the ab- lin (p < 0.05). Nine patients (12.7%) who received placebo and sence of prophylactic antibiotics. Gentamicin-containing collag- three (4.3%) who received cephazolin developed wound infec- enous sponges placed in the cleared disc space were effective in tions (p = 0.07). All but three of the infections in the placebo preventing postoperative spondylodiscitis. This study provides group were confirmed by bacterial culture. All of the organ- Level III therapeutic evidence that for uncomplicated lumbar isms isolated from the patients who received placebo (except microdiscectomy, topical administration of a gentamicin soaked the group-D streptococci which are inherently resistant) were collagen sponge is more effective than placebo in preventing clinically significant discitis. This clinical guideline should not be construed as including all proper methods of care or excluding or other acceptable methods of care reason- ably directed to obtaining the same results. The ultimate judgment regarding any specific procedure or treatment is to be made by the phy- sician and patient in light of all circumstances presented by the patient and the needs and resources particular to the locality or institution