National Physical Therapy Examination (NPTE) Practice Exam

What is an EXCEPTION regarding the cardiovascular and respiratory effects of full immersion hydrotherapy?

1. Increased cardiac volume

2. Reduced HR and reduced systolic BP

3. Increased CO

4. Increased VC

The correct answer is: Increased VC

Full immersion hydrotherapy has specific effects on both the cardiovascular and respiratory systems, and understanding why increased vital capacity (VC) can be viewed as an exception is crucial for grasping the physiological changes that occur during immersion. When a person is fully immersed in water, hydrostatic pressure acts on the body. This pressure results in an increased venous return to the heart, which ultimately enhances cardiac volume. The increase in venous return typically leads to increases in cardiac output (CO) as the heart pumps more efficiently due to a fuller preload. Consequently, the heart rate (HR) often decreases due to the increased stroke volume, which is part of the body's compensation to maintain an adequate blood pressure despite the changes in blood volume dynamics. However, while cardiovascular parameters like cardiac volume and cardiac output are positively impacted, vital capacity does not necessarily increase in the same manner during immersion. In fact, due to the pressure exerted by water, the chest walls may experience a restriction, potentially leading to a reduced functional residual capacity instead of an increased vital capacity. In this context, increased vital capacity during full immersion hydrotherapy stands out as an exceptional claim, because the hydrostatic effects can limit the expansion of the lungs, contrasting with other cardiovascular benefits derived from immersion.