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Prophylactic Antibiotics in Otolaryngology. Department of Otolaryngology University of Ottawa Grand Rounds January 7 th , 2008. James P. Bonaparte, MD, MSc PGY -2. Objectives. Review the basics of antibiotic prophylaxis in surgery
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Prophylactic Antibiotics in Otolaryngology Department of Otolaryngology University of Ottawa Grand Rounds January 7th, 2008 James P. Bonaparte, MD, MSc PGY-2
Objectives • Review the basics of antibiotic prophylaxis in surgery • Discuss common otolaryngology procedures in which antibiotic prophylaxis is commonly used • Discuss controversies related to antibiotic prophylaxis in Otolaryngology • Gain an understanding of the evidence available supporting the use of prophylaxis in Otolaryngology • Understand the potential evidence based risks associated with prophylactic antibiotic use
Overview • Surgical Site Infections • Definitions • Pathogenesis • Antibiotic Prophylaxis Theory • Prophylaxis in Otolaryngology • Head and Neck Surgery • Tonsillectomies • Septorhinoplasty • Nasal Packing • Otology
Prophylactic Antibiotics Surgical Site Infections
Surgical Site Infections (SSI) • CDC’s National Nosocomial Infections Surveillance System (USA)1 • Monitors reported trends in infections • Surgical Site Infections (SSI) are third most common Nosocomial Infection • 14-16% of all Hospital infections • 2/3 were confined to incision • 1/3 involved organs/spaces accessed during OR • When patients with SSI died • 77% were related to SSI • A single SSI prolongs stay by 7 days 1-Emori TG et al. Clin Microbiol Rev. 1993
Consequences of SSI in ENT • Increased Post-Op Death • Penel et al (2004), Penel et al (2005) • Surgical Failure • Penel et al (2004), Govaerts et al (1998), Andrews et al (2006), Rodrigo et al (1997), Liu et al (2008) • Fever • Penel et al (2004), Dhiwakar et al (2006), Burkart et al (2005) • Increased Hospital Stay • Penel et al (2004), Rodrigo et al (1997 ), Johnson et al (1997), Weber et al (1992), Liu et al (2008) • Delay in Radiation Therapy • Penel et al (2004), Penel et al (2001) • Increase cost • Callender et al (1999), Penel et al (2001)
Definition of Surgical Site Infection • NNIS Definition of SSI • Superficial Incisional SSI • Infection within 30 days involving only skin/subcutaneous tissue of incision AND one of: • Purulent Drainage • Positive Culture • A sign of infection (pain, swelling, redness, heat) • A diagnosis by a physician • Deep Incisional SSI • Infection within 30 days involving fascial and/or muscle layersand one of: • Purulence • Spontaneous dehiscence or opened by physician due to symptoms • Abscess • Dx by a physician • Organ Space SSI
Initiating Factors for SSI Creation of wound Presence of bacteria Susceptible host
Initiating Factors for SSI Creation of wound Presence of bacteria Susceptible host
Initiating Factors for SSI Creation of wound Presence of bacteria Susceptible host
Pathogenesis of SSI • Bacterial “Dose” Required for SSI • Greater than 105 per gram of tissue increased risk • Significantly lower if foreign body present • Less than 102 per gram of tissue if silk suture present • Bio-Burden of Saliva • Approximately 108 bacteria per gram of tissue
Factors Influencing SSI • Patient Characteristics • Systemic Factors • Diabetes • Nicotine Use • Steroid Use • Malnutrition • Prolonged Hospital Stay • Pre-operative Colonization by virulent bacteria • Local Factors • Tissue Ischemia • Non-viable tissue • Foreign Bodies • Hematoma • Dead Space • Environment Factors • Perioperative Transfusion • Preoperative Characteristics • Antiseptic Showering • Preoperative hair removal – razor vs shave • Skin Preparation • Surgical team antiseptic • Antimicrobial Prophylaxis • Operative Characteristics • Operating Room – Ventilation, Atire, Drapes, • Surgical Technique • Excessive electrocautery • Post-operative • Wound Care • Post-operative Antibiotics
Factors Influencing SSI • Patient Characteristics • Systemic Factors • Diabetes • Nicotine Use • Steroid Use • Malnutrition • Prolonged Hospital Stay • Pre-operative Colonization by virulent bacteria • Local Factors • Tissue Ischemia • Non-viable tissue • Foreign Bodies • Hematoma • Dead Space • Environment Factors • Perioperative Transfusion • Preoperative Characteristics • Antiseptic Showering • Preoperative hair removal – razor vs shave • Skin Preparation • Surgical team antiseptic • Antimicrobial Prophylaxis • Operative Characteristics • Operating Room – Ventilation, Atire, Drapes, • Surgical Technique • Excessive electrocautery • Post-operative • Wound Care • Post-operative Antibiotics
Principle of Prophylaxis “Antibiotic Prophylaxis is warranted when a surgical procedure or patient susceptibility poses a greater risk than that associated with the administration of the Drug.” How do we calculate Infection Risk? How do we calculated Drug Risk?
Timing and Purpose of Antimicrobial Prophylaxis • Three Primary Methods: • Pre-operative Antibiotics • Dose given prior to incision • Reduces burden of bacteria introduced during OR • Post-operative Antibiotics • Given for varying number of doses post-op • Reduce post-operative contamination • Thus reduce infection risk • Combination
Wound Classification • Clean • Uninfected wound with no inflammation and the respiratory, alimentary or genital tract is not entered. • Closed primarily and using closed drainage • Clean-Contaminated • Operative wound in which respiratory, alimentary, genital/urinary tracts are entered under controlled conditions. • Contaminated • Open, fresh or accidental wounds or major breaks in sterile technique or gross spillage from GI tract • Dirty/Infected • Old traumatic wounds or those with clinical infection or perforated viscera.
Assessment of Surgical Site Infections • Multiple Assessment Scales • Purulence vs No purulence • Common in Otology • Used in all other areas as well • Grades of erythema • Head and Neck • Combination of symptoms and signs • Johnson’s Criteria • Most common in head and neck
Assessment of Surgical Site Infections • Johnson`s Criteria (Johnson et al, 1984) • 0: Normal Healing • 1+: Erythema around suture line limited to 1cm • 2+: 1-5 cm of erythema around suture line • 3+: Greater than 5cm of erythema/induration • 4+: Purulence either spontaneous or through incision • 5+: Orocutaneous fistula formation • 4+ and 5+ often used as definition of positive “SSI” in studies • 1+ to 3+ considered as expected surgical inflammation
Otolaryngology Surgical Site Infections Head and Neck
Head and Neck Clean Procedures
Clean Procedures • Retrospective Studies • Johnson et al (1987) • Carrau et al (1991) • Slattery et al (1995) • Prospective Studies • Mustafa et al (1993) • Seven et al (2004) • Penel et al (2004) • Meta-analysis - 0 • Placebo-Controlled RCT - 0
Clean Head and Neck Procedures: Retrospective • Johnson et al (1987) • Retrospective of 438 patients • Thyroidectomy, parathyroidectomy , parotidectomy and submandibular gland excision • 20% of patients used prophylactic antibiotics (chart review) • SSI=0.7% (3/438) • 2 - No antibiotics • 1 – Received antibiotics • Carrau et al (1991) • Retrospective review of 192 Clean Neck Dissections • Multiple antibiotics dosing and duration utilized • SSI = 6% overall with no difference between those with and without antibiotics • Study had low power to detect difference • Infection correlated with: Flap-use, prior Radiation, length of surgery
Clean Head and Neck Procedures: Retrospective • Slattery et al. (1995) • Retrospective review of 119 Clean Neck Dissections • 25% of patients also underwent other clean procedures • Parotidectomies (14), Thyroidectomy (7), tracheotomies (8) • Compared short (<24h vs Extended >24h) of antibiotics • All patients received Ancef • 31 patients received <24h • 88 patients received >24h • 4% for 48-hours and 70% until drains removed (4.3 days average) • Johnson’s Criteria used for SSI definition • No infections reported • Are Tracheotomies Clean?
Clean Head and Neck Procedures: Prospective • Mustafa et al (1992) • Prospective Double-Blind RCT of 60 patients • Included: Parotidectomies, Thyroidectomies, Submandibular Gland Excisions • Received either 24h or 7 days of cefotaxime (IM) • Used Johnson’s Criteria • SSI=11.6% with no difference between groups • 13% - 24h Group • 10% - 7 day Group • No Antibiotic Complications • Seven et al (2004) • Compared Antibiotic to No Antibiotic in 68 patients • 1.5g amp-sulbac q6h for 24h: SSI = 1.7% (1/57) • No antibiotics: SSI = 13.3% (7/51) • Not true prospective study • Control group identified retrospectively and compared • Both groups had similar definitions of infections • Who assessed for infection in past? How were infections recorded? • Johnson’s Criteria would be very difficult to apply retrospectively
Clean Head and Neck Procedures: Prospective • Penel et al. 2004 • Prospective study: • 221 patients with no prophylactic antibiotics • Neck Dissection (114), Thyroidectomy (50), Parotidectomy (7), Skin Resections (34) • Johnson’s Criteria • Multiple Univariate analysis performed • Overall SSI Rate=6.6% (14/212) • 100% of these in patients with malignant tumors • P=0.06 (too few benign cases to reach significance) • Only 38 benign cases • Risk Factors • Prior Chemotherapy (p=0.0001) • 93% (14/15) oh those with Prior Chemo developed a SSI • 0/197 in those without Prior Chemo
Chemotherapy and Infection • Discussion • Chemo affects the immune system • Reduced number and function of macrophages/neutrophils • B-cell and T-cell Function • Diminished opsonizing activity • Reduced cellular and humoral immunity • Increased susceptibility to pyogenic infections • Even if not neutropenic (wolf et al, 1987) • Adverse effects last up to 6-months • Wolf et al (1987) • No Mention of when chemo was given
Clean Head and Neck ProceduresConclusions • Overall Low Incidence of SSI • 0%-11.6% • 6.6% in Penel et al. (2004) in absence of antibiotics • No study has shown effect of antibiotics • No reported major complications of antibiotics • Antibiotics do not appear to be required in Clean Head and Neck Procedures • Future study to assess: • Coverage for those with clean H/N surgery with Prior Chemotherapy
Head and Neck Clean-Contaminated
Clean-Contaminated Procedures Definition in Otolaryngology Studies: “Skin incision in communication with oral cavity or the aerodigestive tract “ Common Procedures Neck Dissection with communication Laryngectomy, Pharyngectomy Mandibular procedures Floor of mouth resections
Review of the Literature • 3 Risk Factor Assessments • 1 Retrospective Study • 10 RCT assessed (1979-2008) • Multiple antibiotic regimens • Class, Dose, Timing, Duration • Two studies did not assess for SSI • One assessed for pulmonary complications • One assessed for prescribing habits • 5/8 studies used Johnson’s Criteria • Alternate definition include • Presence of purulence or fistula • “Clinician impression” • Erythema around the surgical site • Two compared Antibiotic to placebo • 1 Meta-analysis
SSI Risk Factors in ENT • Penel et al. (2001, 2004, 2005) • Conducted three studies using same population • Used “Johnson’s Criteria” • Prospective study (2001) 165 patients • Received Clindamycin 900mg IV at incision time then 48h • Prospective study (2004) 95 patients • Received amox/clav 1g at incision time then 48 hours • “Prospective” study (2005) • Compared prior two studies retrospectively
Risk Factors for SSI • Clindamycin Group (2001) • Clean-contaminated procedures – communication with aerodigestive tract • Over 30 variables assessed at p<0.05 • True bonferoni adjusted value p<0.0015 • Overall SSI= 41.8% • Positive Risk Factors – Univariate assessment • Tumor stage (p=0.044) • Prior Chemo (p=0.008) • Duration of hospital stay (p=0.022)*Confounding • Laryngectomy stoma (p=0.00008) • Laryngeal/hypopharyngeal cancer (p=0.008)
Risk Factors for SSI • Amox/Clav Group (2004) • Clean-contaminated procedures • Same variables although included some new ones • Overall SSI=50.5% • Risk Factors • High ETOH consumption (p=0.007) • Not included in first study or multivariate analysis • Larynx/Hypopharynx (p=0.02) • Laryngectomy Stoma (p=0.01)
Risk Factors for SSI • Multivariate analysis – (2005) • Compared prior two studies • Pooled patients to perform multivariate analysis • 25 Parameters assessed with p<0.05 • Adjusted rate p<0.002 • Overall SSI rate = 45% • No difference between therapies (p=0.17) • Univariate Risk Factors • Male (p=0.003) • Prior Chemo (p=0.009) • Hypopharyngeal Cancer (p=0.009) • Laryngectomy stoma (p=0.00001) • Multivariate Risk Factors • Laryngectomy Stoma (p=0.001)
Risk Factors for SSI - Discussion • Identified risk factors for • Clean-contaminated H/N Patients • Who received antibiotics • What does this say about those who don’t receive Antibiotics? • Nothing • Why was Male a risk factor in univariate analysis? • Comorbidities? ETHO (significant in one assessment)? • This was a European Population • Why do laryngectomy stoma’s increase risk of infection, even with 2-days of Abx? • Improper coverage • Should we cover longer in these patients
Risk Factors for SSI - Discussion • Notable Insignificant Risk Factors • Prior Radiation • Uni or Bilateral Neck • Flap vs No-Flap • Recurrence vs Primary
Clean Contaminated Surgery Placebo Controlled • Becker et al (1979) • Clean contaminated H/N surgery of 55 patients • Cefazolin Pre-op then q6h for 1 day • Infection Rate: 38% • Placebo • Infection Rate: 87% • Johnson et al (1984) • Clean contaminated H/N of 80 patients • Started “Johnson’s Criteria” • 24h of cefotaxime or placebo • Abx: 10% infection rate • Placebo: 78% infection rate • Interestingly, this rate is lower than Clean H/N Study by Mustafa (1993)
Clean Contaminated Surgery Double-Blind- RCT • Johnson et al (1984) – 107 patients randomized to one of 4 Groups • 15% Overall infection rate • Ancef rate • 24h: 33% • 5-days : 20% • Clinda-gent rate • 24h: 7% • 5-days: 4% • Small Sample • Small sample for 4-factor comparison • No complications • No difference in Vestibular function between groups (ENG) • No changes in auditory function (Pre/post audiogram) • Rodrigo et al (1997) – 159 patients randomized to one of 3 groups • 23% infection rate after 24h hours of: • No difference between 24h of Ancef, Clavulin or Clinda-gent • Small sample for 3-factor comparison • No reported complications
Clean Contaminated Surgery Double-Blind- RCT • Skitarelic et al (2007) – 189 patients randomized to one of 2 groups • 24h of Clavulin vs Ancef • 22% Overall Infection rate • No Significant difference between 24h of • Clavulin: 21% • Ancef: 24% • No significant difference in non-wound related infections (12%) • Liu et al (2008) – 50 Patients randomized to one of 2 groups • 1 vs 2 days of Clindamycin • 24.5% infection rate • No difference between 72h vs 24h of clindamycin • No reported antibiotic related complication
Summary of Comparable RCT • Comparable Studies • All used Johnson’s Criteria for SSI assessment • All contained a variety of procedures • Discussion • Trend for improved rates with longer duration? • Is there evidence of increased harm with this? • Clindamycin ideal for coverage • Does adding Gentamycin improve efficacy?
Gram Negative Coverage • Controversial • Cummings suggests to add gram negative if: • Hospitalized • In Nursing Home • No RCT or Meta-analysis specifically looking at Gram Negative Coverage
Free-Flap StudiesRandomized Controlled Trials • Carroll et al (2003) – 74 patients with flap-reconstruction • Infection defined as: Red wound, “swollen” or purulence • 11% infection rate (8/74) • 8% Developed Fistuas (pharyngeocutaneous) • No difference between 24h and 5 day clindamycin • 1 Patient Developed c. difficilediarrhea • Simons et al (2001) – 62 patients with flap reconstruction • 8.1% infection rate • No difference between 2-days of IV pip-tazovsPiptazo containing Oral mouthwash and IV Piptazo
Meta-Analysis • Velanovich V, (1990) • Included Head and Neck Studies • Clean, Clean-Contaminated • Results • Prophylactic antibiotics compared to placebo • Reduced infection by 43.7% (14.9 to 72.5) • Multiple antibiotics compared to Ancef alone • Reduced infection by 14% (6.2 to 21.2) • Multi drug or 3rd Gen Cephlosporin vs. Single drug • 8.3% (2.4 to 14.2) relative difference compared to single Abx • No difference between single and multiple days • 4.1 (-1.4 to 9.6) relative difference
Meta-Analysis - Discussion • Poor discussion of Search Strategy • Key words? MESH? • Included articles with “Similar methods” but did not indicated what this meant • Quality assessment • No mention of who, how many assessed quality • Compared “pertinent factors” but no identification of the factors • Did not provide explanation on what variables were being assessed • Multidrug and 3rd Gen Cephalosporin considered the same • May not be as 3rd Gen Ceph have reduced Gram Positive Coverage
Clean-Contaminated SurgeryConclusions • Evidence to recommend antibiotics to reduce infections for head and neck surgery • No evidence to recommend >24h of coverage • Trend supporting use of gram negative coverage • Future studies needed • Studies required to assess influence of prior chemotherapy and prophylaxis • Clindamycin appears safe and efficacious • No evidence suggesting 24h of antibiotics increases complications or side-effects
Head and Neck Laryngectomy