History

• 1847 - Semmelweis identifies surgeons hands as route of spread of puerperal infection
• 1865 - Lister introduces hand and wound asepsis with the use of carbolic acid
• 1880 - von Bergmann invents the autoclave

Definitions

• Asepsis is procedure to reduce the risk of bacterial contamination
• Usually involves
  • The use of sterile instruments
  • The use of a gloved no touch technique
• Antisepsis is the removal of transient microorganisms from the skin and a reduction in the resident flora

Preoperative skin preparation

Skin shaving

• Aesthetic and makes surgery, suture and dressing removal easier
• Wound infection rate lowest when performed immediately prior to surgery

• Infection rate increased from 1% to 5% if performed more than 12 hours prior to surgery

• Abrasions can cause colonisation which can lead to wound infection
• Clippers or depilatory creams reduce infection rates to less than 1%.

Skin preparation

• 70% Isopropyl alcohol
  • Acts by denaturing proteins
  • Is bactericidal but short acting
  • Effective against gram-positive and gram-negative organisms
  • Also fungicidal and virucidal
• 0.5% Chlorhexidine
  • Quaternary ammonium compound
  • Acts by disrupting the bacterial cell wall
  • Bactericidal but does not kill spore forming organisms
  • It is persistent and has a long duration of action (up to 6 hours)
  • More effective against gram-positive organisms
• 70% Povidone - iodine
  • Acts by oxidation / substitution of free iodine
  • Bactericidal and active against spore forming organisms
  • Effective against both gram-positive and gram-negative organisms
  • Rapidly inactivated by organic material such as blood
  • Patient skin sensitivity is occasionally a problem
  • No evidence that one is superior to any other

Occlusive adhesive drapes

• No evidence that they reduce infection rate
• May actually increase skin bacterial count during surgery

Bibliography