头颈外科的抗生素应用(英文)antibiotics-in-head-and-neck-surgery课件.ppt

1、Antibiotics in Head and Neck SurgeryDepartment of OtolaryngologyUTMBResident Physician:Karen L.Stierman,M.D.Faculty Physician:Ronald W.Deskin,M.D.Introduction Classification of wounds Commonly used antibiotics Indications for perioperative antibiotics in head and neck surgery Wound Infections Larges

2、t group of postooperative infectious complications of surgery Second most frequent type of nocosomial infectionConsiderations for the use of antibiotic therapy Risk of developing wound infection classification of wound host and local factors Cost of therapy 1992 cost of treating a wound infection$36

3、,000 Side effects and development of resistanceResistance to Antibiotic Therapy Virtually all bacterial pathogens have the ability to acquire resistance to antibiotic therapy This problem is more common in nocosomial pathogens such as VRE and MRSA More recently,community acquired pathogens have deve

4、loped resistant strainsResistant Strept.Pnuemoniae Resistance to penicillin is found in 30 to 70%of isolates depending on the hospital Some strains are also found to be resistant to one of the following:cephalosporins,Bactrim,chloramphenicol,or a macrolide Children are more likely than adults to be

5、infected with strains resistant to chloramphenicol,erythromycin or BactrimClassification of Wounds Clean Clean contaminated Contaminated DirtyClean wounds Associated with an elective case No break in aseptic technique No associated inflammation Infection rate of 1%to 5%Clean Contaminated Wounds Orop

6、haryngeal,respiratory,alimentary or GU tract is entered under controlled conditions Most head and neck surgeries fall under this category Infection rate is 8%to 11%in general,although major head and neck cases have a rate of 28-87%.Contaminated Wounds Result after:Spillage from the GI tract Major br

7、eak in sterile technique With acute nonpurulent inflammation Includes fresh traumatic wounds Infection rate of 15%-17%Dirty Wounds Organisms causing post-operative infection are present prior to operation Wounds associated with old trauma,an abscess,or a perforated viscus.Infection rate greater than

8、 27%Timing Antibiotics are most effective when given before bacteria enters the blood stream or tissue.Studies have shown antibiotics have less effect if given after 3 hours from innoculation.Route Parenteral administration is the traditional route IM injections achieve the highest sustained level.I

9、t is recommended in contaminated cases to administer IV and IM loading doses followed by a continuous IV or intermittent IM injections.Commonly Used AntibioticsPenicillins Act by causing abnormal cell wall development in actively dividing bacterial cells.Groups are as follows:Natural penicillins,pen

10、icillinase resistant penicillins,aminopenicillins,antipsuedomonal penicillins,and extended spectrum penicillins.Natural Penicillins Drug of choice for St.pyogens and St.pneumoniae,and Clostridia perfringens 30%of isolates of St.pneumoniae are penicillin resistant.Oral form in PenV,IM form is PenGSyn

11、thetic Penicillins Include nafcillin,oxacillin,and methicillin,cloxacillin and dicloxacillin.Used when S.aureus is suspected as these drugs are resistant to B-lactamase Side effects include interstitial nephritis,leukopenia,and reversible hepatic dysfunction.Aminopenicillins Include ampicillin and a

12、moxicillin Not effective in presence of B-lactamase Antibiotics of choice for Enterococcus sp.Active against some gram-rods(E.coli and P.mirabilis)Antipsuedomonal Penicillins Include carbenicillin and ticarcillin.Similar gram negative activity as aminopenicillins Poor activity against Klebsiella sp.

13、Side effects:sodium loading and platelet dysfunction Synergistic with aminoglycosides against Psuedomonas.Extended Spectrum Penicillins Include mezlocillin and piperacillin Similar to antipsuedomonal penicillins but more active against Klebsiella sp.and Streptococcus.Cephalosporins Divided into firs

14、t,second,and third generation classes Inhibit bacterial cell wall synthesisFirst Generation Cephalosporins Cephalothin,cephapirin,cephradine,and cefazolin Active against Strept.sp and Staph sp.Limited gram negative activity Side effect:allergic reactions,drug eruptions,phlebitis,and diarrhea.Second

15、Generation Cephalosporins Cefoxitin,cefotetan,cefuroxime Increased gram negative coverage Cefoxitin and cefotetan are more active against anaerobesThird Generation Cephalosporins Cefotaxime,ceftizoxime,ceftriaxone,ceftazidime Less active against Gram positive organisms More active against the Entero

16、bacteriaceae and other Gram negative organisms Side effects include hypersensitivity reaction,hematological disturbances,GI and renal complaints.Macrolides Erythromycin,Pediazole(E-mycin and sulfisoxazole),Azithromycin and Clarithromycin Inhibits protein synthesis Similar spectrum as PenG plus Mycop

17、lasma,Legionella,Actinomyces,and H.infl.Side effects include nausea,vomiting,diarrhea,and hepatitis.Other Antibiotics Clindamycin inhibits protein synthesis Active against most Gram positive,and anaerobic organisms.Good penetration into bones and abscesses.Side effects include psuedomembranous colit

18、is,mild nausea and diarrhea,leukopenia,and hepatotoxicity.Vancomycin Antibiotic of choice for MRSA Associated with nephrotoxicity or ototoxicity when given with aminoglycoside Associated with emergence of VRE Great activity against Staph and Enterococcus.Metronidazole Good for anaerobic organisms We

19、ll absorbed into abscesses Side effects include seizures,cerebellar dysfunction,disulfiram reaction with ETOH,psuedomembranous colitisAminoglycosides Include gentamycin,tobramycin,and amikacin Good gram negative coverage including Pseudomonas Used in head and neck surgery against mixed microbial abs

20、cesses and when organisms from GI tract are suspected.Sulfonamides Bactrim Very active against Gram negative aerobic organisms and some Gram positive such as Staph and Strept.species Should not be used in last month of pregnancyFlouroquinolones Norfloxacin,Levofloxacin,Ciprofloxacin,and Ofloxacin.Go

21、od efficacy against gram negative organisms and some Staph species.Do not use in children or adolescents.Indications for Antimicrobial TreatmentOtologic Surgery Postoperative use of ototopical antimicrobial drops reduces the incidence of otorrhea after tympanostomy tube insertion Studies show a redu

22、ction from 16.4%to 8%when Cortisporin drops are used from 1 to 5 days postopOther Otologic Procedures No significant decrease in postoperative infection rates in those patients treated with perioperative antibiotics Wound infection is prevented more effectively by starting with a dry ear and observi

23、ng good surgical technique Neurotological procedures may require some antibiotic prophylaxis.More studies need to be carried outTonsillar Surgery Antibiotics given 5-7 days post-operatively decrease dysphagia,fever,pain,mouth odor and poor oral intake Ampicillin,amoxicillin in children Augmentin in

24、adults Currently a 7 day course is recommendedOdontogenic Infections Most commonly caused by oral flora Have tendency to deepen causing neck space abscess or cellulitus After appropriate drainage,treatment is recommended with IV penicillin or Cleocin.Can be augmented with Cleocin mouthwashNeck Absce

25、ss Usual organisms are Staph,Strept,and anaerobes High incidence of B-lactamase resistant organisms Antibiotic therapy with or without surgical drainageFacial Fractures Open mandible fractures have been shown to have a 30%decreased incidence of infection when perioperative treatment with clindamycin

26、 or penicillin is used Antibiotics covering the oral flora are recommended in open mandible fractures and any surgical procedures where the wound will be exposed to oral floraLacerations and Soft Tissue Injuries Soft tissue injuries of the head and neck including crush injuries,wounds contaminated b

27、y body secretions,pus or soil,wounds with devitalized tissue and those wounds seen three hours after injury should receive antibioticsDog Bites 5%result in infection Treatment is with Augmentin Need to debride devitalized tissueHuman Bites Staph,Stept,Eikenella,Bacteroides,Peptostrep Treatment is ba

28、sed on length of time from innoculation Augmentin,UnasynNasal and Sinus Surgery Current recommendations are to give anti-staph coverage in patients with nasal packing and to coat merocel packing with antibiotic ointment One study showed patients receiving low dose Erythromycin after FESS reduced pos

29、t-surgical sinusitus complaints.Thyroid,Parotid and Submandibular Surgery No efficacy in giving prophylactic therapy in these casesCranial Base Surgery High risk for postoperative infections More studies need to be done in this area Current recommendation is a single broad spectrum antibiotic for at

30、 least 48 hoursOncological Head and Neck Surgery High risk for infection if surgical site contaminated with aerodigestive secretions Depending on the study,infection rate is from 28-87%without antibiotics.This is reduced to 14%with antibiotic therapy in one study Major fistula is the most common com

31、plicationOncological Head and Neck Surgery(contd)Antibiotics are recommended in major clean contaminated head and neck oncological surgery Time course remains an issue.In most cases at least a short course of 1 to 3 days is effective Need for gram negative coverage One study showed a reduction of in

32、fection rate from 36 to 10%with the addition of an aminoglycosideSummary Decision of whether to give antibiotics is based on the individual case Need to consider cost,side effects and development of resistance,incidence of infection without antibiotics Antibiotics are never a substitute for good surgical technique