Which of the following is an example of a critical medical device that must be sterilized?

In the context of medical devices, critical items are those that enter sterile tissues or the vascular system, representing a high risk of infection if not properly handled. Flexible endoscopes fall into this category because they are designed to penetrate mucous membranes and may contact sterile areas inside the body.

Proper sterilization of flexible endoscopes is imperative to prevent the transmission of pathogens. They are typically processed through high-level disinfection or sterilization methods after each use, depending on their design and intended application. This ensures that all microbial life, including more resistant pathogens, is eliminated before the device is reused.

Other options, such as thermometers and stethoscopes, do not typically enter sterile tissues and are considered semi-critical or non-critical items, thus having less stringent sterilization requirements. Similarly, scissors, while they may come into contact with skin or superficial tissues, do not penetrate sterile areas. This emphasizes the critical nature of flexible endoscopes and the importance of their sterilization in preventing infections in a healthcare setting.