Valsalva maneuver

A Valsalva maneuver is any attempted exhalation against a closed glottis or against a closed mouth and nose. It is also known as Valsalva's test and Valsalva's method, after Antonio Maria Valsalva, a famous Italian anatomist. Valsalva's initial intention for the maneuver was as a method of expressing pus from the middle ear.

A Valsalva maneuver performed against a closed glottis results in a drastic increase in pressure in the thoracic cavity, the airtight section of the torso that houses the lungs and heart. In normal exhalation, the diaphragm relaxes, pushing up and into the thoracic cavity. This increases pressure in the cavity and forces the air out of the lungs. However, when the air cannot escape, as when the glottis is closed in a Valsalva maneuver, pressure simply continues to build inside the abdomen and thoracic cavity until the diaphragm relaxes or the air is allowed to escape. This reduces the amount of blood flow into the thoracic cavity, especially in the veins leading to the right atrium of the heart.

General uses

The Valsalva maneuver is used as a pressure equalization technique by scuba divers and airplane passengers to avoid barotrauma and discomfort inside their ears when they move to a higher pressure breathing environment.

To apply pressure in the eustachian tubes, a person using this technique pinches the nose, closes the mouth, and tries to exhale. The technique works by raising the pressure in the throat so that a small volume of air moves from the throat to the ears through the Eustachian tubes which connect them. It also increases intrathoracic pressure, discussed below.

People inadvertently perform closed-glottis Valsalva maneuvers when blowing up a balloon or "bearing down" for a bowel movement. The increase of thoracoabdominal pressure is reproduced while coughing or sneezing.

Clinical uses

The Valsalva Maneuver is an orthopedic test used to generally screen for a long list of conditions. It may be done with a nose pinch to assess cranial symptoms or without to assess abdominal or thoracic symptoms. The Valsalva test has physiological effects for both a positive and negative result, and the practitioner must differentiate between the two, then follow with more specific tests to assess more specifically.

In a normal (negative) result, if the pressure is held for long enough, one will begin to feel as if pressure were building in the head, followed by dizziness and lightheadedness upon release of the maneuver.

Positive signs include pain, either local to the lesion site or along a dermatomal pattern. Other sensations may be elicited if the lesion affects motor but not sensory nerves.

A positive Valsalva maneuver may point to a space-occupying lesion, such as a herniated disc, osteophyte or tumor, which would increase pressure within the spinal cord or against a specific organ. It is important to follow this very general screening test with more specific orthopedic tests to isolate where a lesion might be, and nature of the ailment. It should be used cautiously with clients who have cardiac disorders, as the temporarily decreased blood supply to the brain may result in post-test dizziness or syncope.

Performing the Valsalva maneuver habitually while bearing down on a bowel movement may lead to the weakening of the large-intestinal wall and the formation of diverticula, or weaken the inguinal tissues in men so that any unusual strain leads to a hernia. Relaxing on the toilet and taking time to let peristalsis do most of the work of defecation, together with a high-fiber diet, can forestall either or both conditions.

The Valsalva maneuver is also used by physicians to ease the entry of their index finger during a digital rectal examination.

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General uses

Clinical uses

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