The correct answer is D, "Clean, sterilize," as this represents the correct order of steps for reprocessing critical medical equipment. According to the Certification Board of Infection Control and Epidemiology (CBIC) guidelines, critical medical equipment—items that enter sterile tissues or the vascular system (e.g., surgical instruments, implants)—must undergo a rigorous reprocessing cycle to ensure they are free of all microorganisms, including spores. The process begins with cleaning to remove organic material, debris, and soil, which is essential to allow subsequent sterilization to be effective. Sterilization, the final step, uses methods such as steam, ethylene oxide, or hydrogen peroxide gas to achieve a sterility assurance level (SAL) of 10⁻⁶, eliminating all microbial life (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.3 - Ensure safe reprocessing of medical equipment). Disinfection, while important for semi-critical devices, is not a step in the reprocessing of critical items, as it does not achieve the sterility required; it is a separate process for non-critical or semi-critical equipment.

Option A (clean, sterilize, disinfect) is incorrect because disinfecting after sterilization is unnecessary and redundant, as sterilization already achieves a higher level of microbial kill. Option B (disinfect, clean, sterilize) reverses the logical sequence; cleaning must precede any disinfection or sterilization to remove bioburden, and disinfection is not appropriate for critical items. Option C (disinfect, sterilize) omits cleaning and incorrectly prioritizes disinfection, which is insufficient for critical equipment requiring full sterility.

The focus on cleaning followed by sterilization aligns with CBIC’s emphasis on evidence-based reprocessing protocols to prevent healthcare-associated infections (HAIs), ensuring that criticalequipment is safe for patient use (CBIC Practice Analysis, 2022, Domain III: Infection Prevention and Control, Competency 3.4 - Implement environmental cleaning and disinfection protocols). This sequence is supported by standards such as AAMI ST79, which outlines the mandatory cleaning step before sterilization to ensure efficacy and safety.