What issue can arise when a patient is set up on PC-CMV mode and exhibits accessory muscle use?

• A. Insufficient oxygenation
• B. Improper sensitivity setting
• C. Excessive tidal volume
• D. Inadequate PEEP levels

Answer: (B)

When a patient is on Pressure-Control Continuous Mandatory Ventilation (PC-CMV) mode and begins to use accessory muscles during respiration, it often indicates an issue with the sensitivity settings of the ventilator. This mode is designed to assist or control the patient's breaths at a set inspiratory pressure. However, if the sensitivity is not set correctly, the patient may have to exert additional effort to initiate a breath.

When the sensitivity is set too high, it can lead to a situation where the patient struggles to trigger the ventilator, resulting in the use of accessory muscles to overcome the cumbersome response of the machine. It reflects a mismatch between the patient's respiratory effort and the ventilator's response to that effort. Adjusting the sensitivity can help ensure that the patient can easily initiate breaths, reducing the need for accessory muscle use and making the overall ventilation process more effective and comfortable for the patient.

Other potential issues like inadequate oxygenation, excessive tidal volume, or inadequate PEEP levels can be concerns in specific contexts but do not directly relate to the immediate issue of muscle use due to improper sensitivity settings in this scenario.