Why do we care?Why do we care?  Wound infection and failure remain common complications  Prolong hospitalization  Increased resource consumption  Increased costs  Increased mortality  Influenced by patient factors and perioperative management

Infection Control: Hand Hygiene  Hand Hygiene  Often neglected  Semmelweis first noted in with 1847: puerperal infections  Resident vs. Transient flora  Even “clean” procedures can result in contamination

Infection Control: Hand Hygiene  Various Hand Hygiene Products  Plain soap and water  Alcohol-based rinses and gels  Chlorhexidine  Iodine and iodophors  Choice depends on expected pathogen, acceptability of HCW’s, and cost (usually $1/patient day).

Infection Control: Hand Hygiene  Barriers to hand hygiene  Skin irritation  Inaccessibility  HCW acceptance

Infection Control: Antisepsis  Masks  Caps  Sterile gloves  Drapes  Decrease OR traffic  Site of line placement

Infection Control: Antibiotic Prophylaxis  Miles et. al used guinea pig model as proof of principle for antibiotic prophylaxis  Knighten et. al assessed the use of high inspired oxygen alone and in addition to prophylactic antibiotics  Classen et. al prospective human study showed same results as Miles.  Standard for surgeries in which greater than minimal risk of infection

Infection Control: Antibiotic Prophylaxis  THA, TKA, extradural ortho and neuro spine, CT, vascular, kidney transplant: Cefazolin  Cranial and intradural spine: Ceftriaxone  Liver transplantation: Ceftriaxone  Colon surgery: Cefotetan  Vaginal and abdominal Hysterectomy: Cefazolin or Cefotetan (if bowel involved)  Dosing depends on weight, redosing interval depends on durgs used.  Discontinued by 24 hours postoperatively

Surgical Site InfectionsSurgical Site Infections  Superficial Incisional (SSI)  Deep Incisional SSI  Organ/Space SSI

Mechanism of Wound Repair  Inflammation  Matrix production  Angiogenesis  Epithelization  Remodeling

Initial Response to InjuryInitial Response to Injury  Starts with skin incision creating a wound  Phases: hemostasis, inflammation, proliferation, and remodeling  Each phase is mediated by contaminants, interaction between cells, cytokines, and other chemical mediators

Initial Response to Injury: Hemostasis  Platelet aggregation and degranulation  Release of chemoattractants and growth factors  Coagulation results

Initial Response to Injury: Inflammation  Bradykinin, complement and histamine released by mast cells  PMN’s arrive almost immediately followed by macrophages in 1-2 days  WBC’s continue cycle of inflamamtion  Characterized by erythema and edema of wound edges

Proliferation  Begins about 4 days after injury  Neovasularization  Angiogenesis  Vasculogenesis  Collagen and Extracellular Matrix Deposition  Oxygen dependent process  Epithelization

Maturation and Remodeling  Ongoing remodeling of granulation tissue and increasing tensile wound strength  Wound will never achieve tensile strength of uninjured skin/tissue  Hypertrophic and keloid scars

Wound Perfusion and Oxygenation  Ischemic or hypoxic tissue susceptible to infection and poor healing  Wound tissue oxygenation dependent on:  Perfusion  Arterial oxygen tension  Hemoglobin dissociation conditions  Local oxygen consumption  Carrying capacity

Wound Perfusion and Oxygenation  Avoid vasoconstrictors  Keep patient warm

Preoperative ManagementPreoperative Management  Address modifiable risk factors  Optimize cardiopulmonary function  Treat vasoconstriction  Treat existing infection  Administer appropriate antibiotics  Glucose control

Intraoperative ManagementIntraoperative Management  Administer appropriate antibiotics and re-dose at indicated intervals  Maintain normothermia  Elevate PaO2  Gentle surgical technique  Keep wound moist  Antibiotic irrigation  Delay closure for contaminated wounds  Use appropriate suture and dressings  Judicious fluid administration

Postoperative ManagementPostoperative Management  Pain control  Maintain adequate blood volume  Keep patient warm  Avoid vasoactive substances  Maintain PaO2  Maintain glycemic control

Summary  Anesthesiologists have opportunity to enhance wound healing during perioperative management