What is the maximum external diameter of a suction catheter in relation to the inside diameter of the endotracheal or tracheostomy tube?

The maximum external diameter of a suction catheter should be no greater than 1/2 the inside diameter of the endotracheal or tracheostomy tube. This guideline ensures that appropriate suctioning can take place without causing undue obstruction of airflow. If the catheter were larger than half the diameter, it could diminish the effective cross-sectional area of the tube, leading to increased resistance and the potential for inadequate ventilation. Maintaining this proportion allows for optimal airflow while also ensuring that the catheter can effectively remove secretions without causing trauma to the airway. Overall, adhering to this principle is vital for patient safety and effective respiratory management.