Infection Control in Operating Room

OR Environment & Design - Fortress Against Bugs

• Zoning: Defines access & attire.
  • Unrestricted: Street clothes.
  • Semi-restricted: Scrubs, cap.
  • Restricted (OR proper): Scrubs, cap, mask.
• Air Quality (Critical):
  • Positive Pressure: 10-15 Pa higher than corridors.
  • Air Changes: ≥20 ACH (total); ≥4 fresh air.
  • HEPA Filters: Remove 99.97% of 0.3 µm particles.
  • Laminar flow: For ultra-clean ORs (e.g., implants).
• Physical Environment:
  • Temperature: 20-23°C.
  • Humidity: 30-60%.
  • Surfaces: Seamless, non-porous, easily cleanable.
  • Lighting: Shadowless, adjustable.
• Traffic Control: Minimize movement.

⭐ Positive pressure (10-15 Pa) in OR suite prevents entry of contaminated air from less clean adjacent areas.

Sterilization & Disinfection - The Germ Warfare

• Sterilization: Kills ALL microbes, including spores.
  • Moist Heat (Autoclave): 121°C, 15 psi, 15-20 min. For instruments. 📌 Autoclave All Alive.
    • Prions: 134°C, 3-5 min.
  • Dry Heat (Hot Air Oven): 160°C for 2 hrs / 170°C for 1 hr. For glassware, oils.
  • Chemical: ETO: heat-sensitive items (plastics); 2% Glutaraldehyde: >10 hrs (endoscopes); Plasma (H₂O₂).
  • Radiation: Gamma rays for disposables.
• Disinfection: Kills most microbes; spores may survive.
  • High-level: 2% Glutaraldehyde (<45 min), Peracetic acid.
  • Intermediate: Alcohols (70%), Iodophors, Phenolics.
  • Low-level: QACs (Quaternary Ammonium Compounds).
• Antisepsis: On living tissue (Povidone-iodine, Chlorhexidine).
• Monitoring Sterilization:
  • Biological indicators (spore tests) = gold standard.

    ⭐ Geobacillus stearothermophilus spores are used to monitor steam autoclaves. oka

Surgical Team Protocol - The Sterile Sentinels

• Goal: Prevent SSI via strict team discipline & aseptic techniques.
• Hand Hygiene (Surgical Hand Antisepsis):
  • Method: Timed scrub or counted strokes.
  • Agents: Chlorhexidine (preferred), Povidone-Iodine.
  • Duration: Initial scrub 3-5 min; subsequent 2-3 min.
• Surgical Attire:
  • Clean, dedicated scrubs (non-sterile).
  • Head cover (all hair & scalp covered).
  • High-filtration surgical mask (fit-tested if N95).
  • Shoe covers (optional, per hospital policy).
• Sterile Gowning & Gloving:
  • Performed after hand antisepsis.
  • Gown: Sterile, fluid-resistant.
  • Gloves: Sterile; double-gloving recommended (esp. ortho/trauma).
  • 📌 Gloves Over Gown cuff (closed gloving technique preferred).
• Maintaining Sterility in OR:
  • Face sterile field; never turn back.
  • Keep sterile items & hands above waist/table level.
  • Minimize movement & talking near sterile field.

⭐ Movement of personnel should be minimized when sterile fields are open. Doors to the OR should be kept closed. Traffic in/out of the OR is a major source of airborne contaminants.

Patient & Intra-op Asepsis - Shielding the Host

• Patient Prep:
  • Pre-op shower: Chlorhexidine Gluconate (CHG).
  • Hair removal: Clipping (preferred over shaving) immediately pre-surgery if interfering.
  • Skin antisepsis: Povidone-iodine or Chlorhexidine-alcohol; crucial drying time.
• Intra-op Measures:
  • Sterile surgical drapes: Isolate operative field.
  • Strict adherence to sterile field.
  • Minimize OR traffic & door openings.
  • Gentle tissue handling; wound irrigation.

⭐ Chlorhexidine-alcohol solutions for skin antisepsis demonstrate superior efficacy in reducing SSIs compared to povidone-iodine. oka

High‑Yield Points - ⚡ Biggest Takeaways

• OT ventilation: Maintain positive pressure with ≥15 air changes/hour (minimum 3 fresh).
• HEPA filters: Essential for removing 99.97% of airborne particles ≥0.3 µm.
• Surgical attire: Includes scrub suit, cap, mask; shoe covers are often used.
• Surgical hand antisepsis: Critical before gloving; use chlorhexidine or povidone-iodine.
• Prophylactic antibiotics: Administer IV within 60 minutes before surgical incision.
• Instrument sterilization: Autoclaving (steam sterilization) is the preferred method.
• OR traffic: Keep movement to a minimum to reduce airborne contamination.