Valsalva maneuver

The Valsalva maneuver is a common medical procedure often employed in both diagnostic and therapeutic settings. It's named after the 17th-century Italian anatomist Antonio Maria Valsalva, who first described its utility in the examination of the ear.

Description

The Valsalva maneuver is performed by moderately forceful attempted exhalation against a closed airway, usually done by closing one's mouth, pinching one's nose shut while expelling air out as if blowing up a balloon.

Medical Uses

Diagnostic

The maneuver can be used in a medical examination as a test of cardiac function and autonomic nervous control of the heart. Variations of the maneuver can be used to diagnose conditions such as orthostatic hypotension and POTS.

Therapeutic

In addition to its diagnostic uses, the Valsalva maneuver can also be used therapeutically to clear the ears and sinuses (that is, to equalize pressure between them) when ambient pressure changes, such as in scuba diving, hyperbaric oxygen therapy, or air travel. It can also be used to terminate supraventricular tachycardia (SVT), a rapid heart rhythm originating at or above the atrioventricular node.

Procedure

During the Valsalva maneuver, individuals are typically asked to take a deep breath and then forcibly exhale against a closed airway. This can be achieved by closing the mouth and pinching the nose shut while "bearing down" or attempting to exhale. This causes various physiologic changes, including increased intrathoracic pressure, decreased venous return to the heart, and, ultimately, changes in heart rate and blood pressure.

Risks

Despite its benefits, the Valsalva maneuver is not without risks. It can potentially lead to the development of barotrauma, particularly in those with underlying lung disease. It should be used with caution in individuals with cardiovascular disease, as the changes in heart rate and blood pressure can potentially exacerbate these conditions.

Physiology

The Valsalva maneuver consists of four distinct phases, each with its own physiological response.

Phase One

The onset of the maneuver where intrathoracic pressure increases, causing a brief rise in blood pressure due to compression of the aorta.

Phase Two

The pressure continues to build up within the thoracic cavity, leading to a decrease in venous return to the heart and subsequently a drop in cardiac output and blood pressure. The body compensates by increasing the heart rate and constricting peripheral blood vessels to maintain blood flow to vital organs.

Phase Three

This phase begins when the individual stops straining, leading to a sudden drop in intrathoracic pressure. This briefly leads to further decreased blood pressure.

Phase Four

The final phase is characterized by a rapid increase in cardiac output and blood pressure. This is due to the sudden increase in venous return to the heart following the release of intrathoracic pressure. The body responds by decreasing the heart rate to prevent a sudden surge in blood pressure.

See Also

• Barotrauma
• Orthostatic hypotension
• POTS
• Hyperbaric oxygen therapy
• Supraventricular tachycardia

References

Valsalva maneuver Resources
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