Key Takeaways

  • The OR should be cleaned and checked before each case — the surgical technologist assists with room turnover
  • Room temperature is typically maintained between 68-73°F (20-23°C) with humidity at 30-60%
  • Positive pressure ventilation in the OR prevents contaminated air from entering from hallways
  • Operating room air is filtered through HEPA filters and undergoes 15-20 air exchanges per hour
  • The back table and Mayo stand should be set up using aseptic technique before the patient enters
  • Instruments are organized on the back table systematically: sharps, clamps, retractors, and specialty instruments
  • The Mayo stand holds instruments for immediate use during the current phase of the procedure
  • Equipment check includes suction, electrosurgical unit (ESU/Bovie), lights, table, and monitors
Last updated: February 2026

Operating Room Setup & Preparation

The surgical technologist plays a central role in preparing the operating room for each surgical case. Proper room setup ensures patient safety, efficiency, and maintenance of the sterile field.


Environmental Controls

The OR environment is carefully controlled to minimize the risk of surgical site infections:

ParameterStandardPurpose
Temperature68-73°F (20-23°C)Patient thermoregulation; reduces microbial growth
Humidity30-60%Prevents static electricity; reduces microbial proliferation
Air Exchanges15-20 per hour (minimum 3 fresh air)Dilutes airborne contaminants
Air FiltrationHEPA filters (99.97% efficiency)Removes particles ≥ 0.3 microns
Air PressurePositive pressurePrevents contaminated air from entering the OR
TrafficRestricted movement, doors closedReduces airborne particle counts

Key Point: The OR maintains positive pressure relative to the hallway. This means air flows out of the OR when the door opens, preventing contaminated hallway air from entering. The exception is rooms for immunocompromised patients (negative pressure) and isolation rooms.


Back Table Setup

The back table is the main sterile work surface where instruments and supplies are organized:

  1. Open the sterile back table pack using proper technique (open away from you first, then sides, then toward you)
  2. Don sterile gown and gloves before touching any sterile items
  3. Organize instruments in a logical, systematic order:
    • Sharps: Scalpels, scissors (on a magnetic mat or towel)
    • Clamps: Hemostats, Kellys, Allis, Kocher, Babcock
    • Retractors: Army-Navy, Richardson, Deaver, self-retaining
    • Specialty instruments: Based on the specific procedure
  4. Count all items with the circulating nurse: sponges, sharps, and instruments
  5. Prepare sutures and ties as needed for the case
  6. Load and organize syringes: Label all medications and solutions on the sterile field

Mayo Stand Setup

The Mayo stand (also called the Mayo tray) holds instruments needed for the immediate phase of the procedure:

  • Positioned over the patient but not touching the sterile drapes
  • Set up with instruments for the current step of the procedure
  • Contents change as the procedure progresses
  • Typically includes: scalpel, hemostats, scissors (Metzenbaum and suture), forceps (tissue and smooth), retractors, and suction tip

Equipment Verification Checklist

Before the patient enters the OR, the following equipment must be checked:

  • Suction: Test that suction is functional and set to appropriate pressure
  • Electrosurgical Unit (ESU/Bovie): Verify settings and that the dispersive (grounding) pad is available
  • OR table: Check positioning capability, safety straps, padding
  • Overhead lights: Positioned and functional
  • Monitors: Powered on, correctly positioned for the surgical team
  • Anesthesia machine: Verified by anesthesia team
  • Tourniquet (if applicable): Tested and functioning
  • Specialty equipment: Laparoscopic tower, microscope, C-arm, etc.
Test Your Knowledge

What is the recommended temperature range for an operating room?

A
B
C
D
Test Your Knowledge

The operating room maintains positive air pressure relative to the hallway. The primary purpose of this is to:

A
B
C
D
Test Your KnowledgeOrdering

Place the following steps of opening a sterile back table pack in the correct order:

Arrange the items in the correct order

1
Open the flap nearest to you (toward you)
2
Open the flap farthest from you (away from you)
3
Open the left side flap
4
Open the right side flap
Test Your Knowledge

Which instrument setup is positioned directly over the patient during surgery?

A
B
C
D
Test Your Knowledge

How many minimum air exchanges per hour are required in the operating room?

A
B
C
D