Linens & Surgical Instruments are autoclaved for 30 minutes at?

Hariyana-CHO-2021

Applied Microbiology & Infection control

Easy

Appeared in: Hariyana-CHO-2021

Explanation

The standard protocol for steam sterilization (autoclaving) of wrapped items like linens and surgical instruments is to maintain a temperature of 121°C.
To achieve and maintain a steam temperature of 121°C, a pressure of 15 pounds per square inch (psi) is required.
The typical duration for this standard cycle is 15 to 30 minutes, which ensures the destruction of all microorganisms, including highly resistant bacterial spores.
The question specifies a 30-minute duration, which directly corresponds to the standard cycle parameters.

Option B: A pressure of 30 lbs/sq. inch is too high for a standard 30-minute cycle. This pressure is associated with higher temperatures (around 134°C).
Option C: A pressure of 20 lbs/sq. inch is not a standard setting for routine autoclave cycles for linens and instruments.
Option D: A pressure of 40 lbs/sq. inch is excessively high for standard medical autoclaves and is not used for sterilizing linens or surgical instruments.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Autoclave Sterilization Parameters as background academic context rather than a clinical decision trigger.
A nurse's understanding of correct sterilization parameters is fundamental to infection control and patient safety. Using improperly sterilized instruments can lead to severe surgical site infections (SSIs).
Nurses, especially in the operating room and central sterile supply department (CSSD), are responsible for verifying that sterilization cycles have met the required parameters by checking physical printouts and chemical/biological indicators.
What if? If a specific surgical instrument is dropped during a procedure and is needed urgently, the nurse should know that a 'flash' cycle (e.g., 134°C, 30 psi, 3-10 minutes) can be used for the unwrapped instrument, but this is an emergency measure and not a substitute for routine terminal sterilization.

How to Approach the Question

First, identify the key components of the question: the items being sterilized (linens & surgical instruments), the method (autoclaved), and the duration (30 minutes).
The question asks for the pressure. This requires recalling the standard parameters for steam sterilization.
Recall that autoclaving uses steam under pressure to achieve temperatures high enough for sterilization.
Remember the two main types of cycles: the standard cycle for wrapped goods and the flash cycle for urgent, unwrapped items.
The 30-minute duration points towards the standard cycle. The standard parameters for this are 121°C at 15 psi.
Evaluate the options: 15 psi matches the standard. 30 psi corresponds to the shorter flash cycle. 20 and 40 psi are not standard pressures for this application. This confirms 15 psi is the correct answer.

Concept Tested & Keywords

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E6 Parks TextBook of Preventive & Social Medicine part 1 — Subpart A (pp 26-201 of 604) p. 127-129

E6 Microbiology OneStop Sastry p. 50-52