Which of the following is a physiological risk of the Trendelenburg position? 

• A. Decreased pressure on the diaphragm. 
• B. Decreased cranial pressure. 
• C. Increased respiratory capacity.  
• D. Increased cranial pressure.  

Answer: (D)

Verified step by step guidance

1. Step 1: Understand the Trendelenburg position, which involves placing the patient on their back with the body tilted so that the head is lower than the feet.
2. Step 2: Consider the physiological effects of this position, particularly how gravity affects blood flow and pressure within the body.
3. Step 3: Analyze how the position impacts the diaphragm and respiratory system; since the abdominal organs shift towards the chest, this can increase pressure on the diaphragm, potentially decreasing respiratory capacity rather than increasing it.
4. Step 4: Evaluate the effect on cranial pressure; with the head lower than the feet, venous return from the brain can be impeded, leading to increased intracranial (cranial) pressure.
5. Step 5: Conclude that among the options, the physiological risk associated with the Trendelenburg position is increased cranial pressure, due to the gravitational effects on blood flow and pressure in the head.