18. Classification of surgical wounds and use of antibiotics Flashcards
- Classification of surgical wounds and use of antibiotics
Classification of surgical wounds
-classified by degree of contamination–help predict the likelihood of infection
-having more than 105 bacteria per gram of tissue–bacterial infection
-infection rate for all types of surgical wounds approximately 5%
-four categories:
1)clean
2)clean-contaminated
3)contaminated
4)dirty
Wound classification system
-clean
>nontraumatic, nininflamed operative wounds in which the respiratory,gastrointestinal,genitourinary,and oropharyngeal tracts are not entered
>procedure type:exploratory laparotomy,elective neuter, total hip replacement,PDA(patent ductus arteriosus)
-clean-contaminated
>operative wounds in which the respiratory,gastrointestinal,or genitourinary tract is entered under controlled conditions without unusual contamination;an otherwise clean wound in which a drain is placed
>procedure type:bronchoscopy,cholecystectomy(remove gall bladder),small intestinal resection(remove damaged part of small intestine),enterotomy
-contaminated
>open,fresh,accidental wounds;procedures in which gastrointestinal contents or infected urine is spilled or a major break in aseptic technique occurs
>procedure type:bile spillage during cholecystectomy or biliary diversion procedures,open cardiac massage,cystotomy(remove bladder stones) with spillage of infected urine,lacerations
-dirty
>old traumatic wounds with purulent discharge,devitalized tissue,or foreign bodies;procedures in which a viscus is perforated or fecal contamination occurs
>excision or drainage of an abscess,peritonitis(inflammation of lining of abdomen),perforated intestinal tract,ruptured gallbladder caused by necrotizing cholecystitis,bullae osteotomy for otitis media
Clean wounds
-infection rate 0% – 6%
-antibiotics usually not warranted
-prophylactic antibiotics (AB) appear to be indicated in some clean procedures(orthopedic implants)
-given at induction(30 to 60 minutes prior to incision)
-discontinued within 24 hours of the procedure(at the end of surgery)
-most likely postoperative infection–severe trauma with multiple fractures,traumatic procedures,orthopedic surgery
Clean-contaminated wounds
-minor break in aseptic technique(breakage of gloves)
-infection rate 4.5% – 9.3%
-antimicrobial prophylaxis indicated
-choice of antibiotic based on anticipated flora
-most likely postoperative infection– clean-contaminated fractures of the pelvis and long bones
Contaminated wounds
-not infected initially,but have the potential
-infection rate 5.8% – 28.6%
-antimicrobial prophylaxis indicated
-choice of antibiotic based on anticipated flora,then modified according
to culture and sensitivity results
-most likely postoperative infection–contaminated fractures of the pelvis
and long bones;contaminated urogenital procedures
-delicate debridement,copious lavage,antibiotic therapy→clean wound
-inadequate therapy→dirty wound
Dirty wounds
-gross infection present at the time of surgical intervention
-(traumatic wounds with retained devitalized tissue,foreign bodies,fecal contamination)
-antibiotic therapy,later modified according to culture and sensitivity
results
-copious lavage,debridement
Antibiotic treatment(part of treatment plan)
-antibiotics commonly misused(often based on tradition rather than on
expected bacterial flora)
-development of antibiotic-resistant bacteria
-prophylactic use(ennaltaehkäisevä käyttö)
>significant risk of infection
>infection would be catastrophic
-therapeutic use
>ideally based on culture and susceptibility results
>delay might be problematic
>some antibiotics are bacteriostatic(prevent growth of bacteria) at lower and bactericidal(kills the bacteria)at higher
concentrations–selection according to susceptibility!
Prophylactic use of antibiotics
-must be present at the site during the time of potential contamination
-not a substitute for proper aseptic technique
-rational selection of AB
>effective against at least 80% of probable pathogens
-cefazolin (cefuroxime)
>no adverse effects on platelet aggregation,bleeding time,platelet size or count,prothrombin or activated partial thromboplastin time
-given 30–60 min i.v. before incision and discontinued within 24 h(ideally at the end of the procedure)
Examples of procedures that warrant(oikeutettu käyttö)prophylactic antibiotics
-general indications:
>surgery time longer than 90min
>prosthesis implantation(e.g.,mesh,pacemaker,vascular prothesis,bone cement)
>patients with a preexisting prothesis(e.g.,total hip,pacemaker,bone cement)undergoing surgical procedures(e.g.,dental prophylaxis,traumatic wounds,colorectal surgery)
>severely contaminated or traumatized wounds
-orthopedic procedures
>total hip replacement
>open fracture repair
>extensive fracture repair
>other elective procedures
-respiratory procedures
>resection of infected lobe or lobes
>closure of esophagobronchial fistula
-gastrointestinal procedures
>colonic anastomosis or colectomy
>strangulation or obstruction
>pancreatic abscess
>gastric resection for gastric dilation-volvulus
>anal and rectal surgery
>esophageal surgery
>perineal herniorrhaphy
>hepatobiliary surgery with infection
-urogenital procedures
>renal,ureteral,bladder,or urethral surgery with infected urine
Most commonly isolated microorganisms
-thoracic surgeries(pulmonary and cardiovascular procedures)
>staphylococcus spp.-gram-negative bacilli
-orhtopedic surgeries(e.g.total hip replacement,prolonged internal fixation)
>staphylococcus spp.
-gastric and upper intestinal surgeries(high-risk patients)
>gram-positive cocci,enteric gram-negative bacilli,anaerobes
-biliary tract surgeries(high-risk patients)
>enteric gram-negative bacilli,anaerobes(especially streptococcus spp.,clostridium spp.)
-colorectal surgeries
>enteric gram-negative bacilli,anaerobes(especially bacteroides spp.,streptococcus spp.)
-urogenital systems(eg.,with pyometra,endometritis)
>escherichia coli,streptococcus spp.,anaerobes
-deep,penetrating wounds(e.g.,wounds less than 6 hr old,bite wounds)
>anaerobes,facultative bacteria
-dentistry(patients with valvular heart disease)
>staphylococcus spp.,streptococcus spp.,facultative bacteria,anaerobes
Therapeutic use of antibiotics(e.g.clavaseptin)
-based on clinical judgement,knowledge of the antibiotic’s mechanism
of action,microbiologic factors
-indicated in patients with:
>overwhelming systemic infection
>when infection is present at the surgical site or in a body cavity
>with any contaminated or dirty surgical procedure
-ideal drug is the least toxic,kills bacteria at the site of infection and
does not negatively influence the host immune system
-generally instituted before surgery and continued 2-3 days after
apparent resolution of infection
Therapeutic antibiotics
-with most surgical infections, antibiotic
therapy needs additional therapy
-(drainage of accumulations, debridement
continued lavage, removal of foreign
bodies or implants)
- ‘’drugs of last resort’’ only if necessary
Use of antibiotics
-clean
>prophylactic AB -(+/-)
>therapeutic AB -
-clean-contaminated
>prophylactic AB +
>therapeutic AB -
-contaminated
>prophylactic AB +
>therapeutic AB +
-dirty
>prophylactic AB -/+(started earlier)
>therapeutic AB +
