A hospital CSSD runs the standard gravity displacement steam sterilization cycle for wrapped surgical instruments. Which combination of temperature, pressure and holding time defines this reference cycle?
- A 160 degrees Celsius at atmospheric pressure for 2 hours
- B 134 degrees Celsius at 30 psi for 3 minutes
- C 121 degrees Celsius at 15 psi for 15 minutes ✓
- D 115 degrees Celsius at 10 psi for 30 minutes
Correct answer: C. 121 degrees Celsius at 15 psi for 15 minutes
Explanation
The standard downward displacement autoclave cycle operates at 121 degrees Celsius and 15 psi (about 103 kPa above atmospheric) held for 15 minutes, which kills all vegetative bacteria and spores including Geobacillus stearothermophilus. Option B describes the flash or porous-load cycle used for unwrapped instruments at higher temperature for a shorter time. Option A is a hot air oven setting, and option D is inadequate for reliable spore destruction.
Reference: Ananthanarayan and Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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