Valsalva maneuver

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Valsalva maneuver.jpg

The Valsalva maneuver or Valsalva manoeuvre is performed by moderately forceful attempted exhalation against a closed airway, usually done by closing one's mouth, pinching one's nose shut while pressing out as if blowing up a balloon. Variations of the maneuver can be used either in medical examination as a test of cardiac function and autonomic nervous control of the heart, or to "clear" the ears and sinuses (that is, to equalize pressure between them) when ambient pressure changes, as in diving, hyperbaric oxygen therapy, or air travel.

The technique is named after Antonio Maria Valsalva,1 a 17th-century physician and anatomist from Bologna whose principal scientific interest was the human ear. He described the Eustachian tube and the maneuver to test its patency (openness). He also described the use of this maneuver to expel pus from the middle ear.

A modified version is done by expiring against a closed glottis. This will elicit the cardiovascular responses described below but will not force air into the Eustachian tubes.

Physiological response

Blood pressure (systolic) and pulse rate during a normal response to Valsalva’s maneuver. Forty millimeter mercury pressure is applied at 5 seconds and relieved at 20 seconds.

The normal physiological response consists of four phases.2

  1. Initial pressure rise
    On application of expiratory force, pressure rises inside the chest forcing blood out of the pulmonary circulation into the left atrium. This causes a mild rise in stroke volume.
  2. Reduced venous return and compensation
    Return of systemic blood to the heart is impeded by the pressure inside the chest. The output of the heart is reduced and stroke volume falls. This occurs from 5 to about 14 seconds in the illustration. The fall in stroke volume reflexively causes blood vessels to constrict with some rise in pressure (15 to 20 seconds). This compensation can be quite marked with pressure returning to near or even above normal, but the cardiac output and blood flow to the body remains low. During this time the pulse rate increases (compensatory tachycardia).
  3. Pressure release
    The pressure on the chest is released, allowing the pulmonary vessels and the aorta to re-expand causing a further initial slight fall in stroke volume (20 to 23 seconds) due to decreased left atrial return and increased aortic volume, respectively. Venous blood can once more enter the chest and the heart, cardiac output begins to increase.
  4. Return of cardiac output
    Blood return to the heart is enhanced by the effect of entry of blood which had been dammed back, causing a rapid increase in cardiac output (24 seconds on). The stroke volume usually rises above normal before returning to a normal level. With return of blood pressure, the pulse rate returns towards normal.

Deviation from this response pattern signifies either abnormal heart function or abnormal autonomic nervous control of the heart. Valsalva is also used by dentists following extraction of a maxillary molar tooth. The maneuver is performed to determine if a perforation or antral communication exists.

Normalizing middle-ear pressures

When rapid ambient pressure increase occurs as in diving or aircraft descent, this pressure tends to hold the Eustachian tubes closed, preventing pressure equalization across the ear drum, with painful results.345 To avoid this painful situation, divers, caisson workers and aircrew attempt to open the Eustachian tubes by swallowing, which tends to open the tubes, allowing the ear to equalize itself.

If this fails, then the Valsalva maneuver may be used. It should be noted this maneuver, when used as a tool to equalize middle ear pressure, carries with it the risk of auditory damage from over pressurization of the middle ear.4678 It is safer, if time permits, to attempt to open the Eustachian tubes by swallowing a few times, or yawning. The effectiveness of the "yawning" method can be improved with practice; some people are able to achieve release or opening by moving their jaw forward or forward and down, rather than straight down as in a classical yawn,4 and some can do so without moving their jaw at all. Opening can often be clearly heard by the practitioner, thus providing feedback that the maneuver was successful.

During swallowing or yawning, several muscles in the pharynx (throat) act to elevate the soft palate and open the throat. One of these muscles, the tensor veli palatini, also acts to open the eustachian tube. This is why swallowing or yawning is successful in equalizing middle ear pressure. Contrary to popular belief, the jaw does not pinch the tubes shut when it is closed. In fact, the eustachian tubes are not located close enough to the mandible to be pinched off. People often recommend chewing gum during ascent/descent in aircraft, because chewing gum increases the rate of salivation, and swallowing the excess saliva opens the eustachian tubes.

In a clinical setting the Valsalva maneuver will commonly be done either against a closed glottis, or against an external pressure measuring device, thus eliminating or minimizing the pressure on the Eustachian tubes. Straining or blowing against resistance as in blowing up balloons has a Valsalva effect and the fall in blood pressure can result in dizziness and even fainting.

Diving

In diving, the Valsalva maneuver is often used on descent to equalise the pressure in the middle ear to the ambient pressure. If the Valsalva maneuver is conducted during ascent, residual air overpressure in the middle-ear can potentially be released through the Eustachian tubes. During decompression stops at the end of a dive, if the diver unwittingly slightly descends again and makes a Valsalva to relieve his ears, there exists a non-negligible risk to transfer nitrogen bubbles from one side of the heart to the other one if the foramen membrane is permeable. If some of the inert gas-laden blood passes through the patent foramen ovale (PFO), it avoids the lungs and the inert gas is more likely to form large bubbles in the arterial blood stream, causing decompression sickness.citation needed

A Valsalva maneuver at the end of a dive must never be attempted as it can cause a decompression accident with severe neurological consequences (gas bubbles in the brain or damages to the spinal cord). Repeated Valsalva maneuvers are also suspected to increase the permeability of the foramen for divers at risk.citation needed

Heart Information

The Valsalva maneuver may be used to arrest episodes of supraventricular tachycardia.910 The maneuver can sometimes be used to diagnose heart abnormalities, especially when used in conjunction with echocardiogram.11 For example, the Valsalva maneuver increases the intensity of hypertrophic cardiomyopathy murmurs, namely those of dynamic subvalvular left ventricular outflow obstruction. At the same time, the Valsalva maneuver decreases the intensity of most other murmurs, including aortic stenosis and atrial septal defect.

Effect of Valsalva Cardiac Finding
Decreases Murmur
Aortic stenosis
Pulmonic stenosis
Tricuspid regurgitation
Increases Murmur
Hypertrophic cardiomyopathy, mitral valve prolapse

The Valsalva maneuver works by decreasing preload to the heart. A complementary maneuver for differentiating disorders is the handgrip maneuver, which increases afterload.

The Valsalva maneuver (in the straining phase) reduces the filling of the right and then the left side of the heart. Stroke volume and blood pressure falls, while the heart rate increases.

Neurology

The Valsalva maneuver is used to aid in the clinical diagnosis of problems or injury in the nerves of the cervical spine.12 Upon performing the Valsalva maneuver, intraspinal pressure slightly increases. Thus, neuropathies or radicular pain may be felt or exacerbated, and this may indicate impingement on a nerve by an intervertebral disc or other part of the anatomy. Headache and pain upon performing the Valsalva maneuver is also one of the main symptoms in Arnold–Chiari malformation. The Valsalva maneuver may be of use in checking for a dural tear following certain spinal operations such as a microdiscectomy. An increase in intra-spinal pressure will cause CSF to leak out of the dura causing a headache.citation needed

Urogenital

The Valsalva maneuver is used to aid diagnosis of intrinsic sphincteric deficiency (ISD) in urodynamic tests. Valsalva leak point pressure is the minimum vesicular pressure that is associated with urine leakage. Although there is no consensus on the threshold value, values > 60 cm H2O are commonly considered to indicate hypermobility of the bladder neck and normal sphincter function.13 Also, when examining women with pelvic organ prolapse, asking the patient to perform the Valsalva maneuver is used to demonstrate maximum pelvic organ descent.14

Valsalva retinopathy

A pathologic syndrome associated with the Valsalva maneuver is Valsalva retinopathy.15 It presents as preretinal hemorrhage (bleeding in front of the retina) in people with a history of transient increase in the intrathoracic pressure and may be associated with heavy lifting, forceful coughing, straining on the toilet, or vomiting. The bleeding may cause visual loss if it obstructs the visual axis, and patients may note floaters in their visual field. Usually this causes no permanent visual impairments, and sight is fully restored.

Valsalva device in spacesuits

On 25 May 2011, NASA reported that during the second spacewalk of Space Shuttle mission STS-134, astronaut Drew Feustel was able to clear tears from his eye by wiggling down far enough in his Extravehicular Mobility Unit (spacesuit) to make use of "a spongy device called a Valsalva that is typically used to block the nose in case a pressure readjustment is needed."16 The tears came about because some of a film of anti-fogging agent (liquid soap) came free from the inside of the helmet and floated into his eye.

In November 2011 ESA astronaut Samantha Cristoforetti posted on Twitter a picture of her demonstrating the use of the Valsalva device in the Sokol space suit.17

See also

References

  1. ^ synd/2316 at Who Named It?
  2. ^ Luster, EA; Baumgartner, N; Adams, WC; Convertino, VA (1996). "Effects of hypovolemia and posture on responses to the Valsalva maneuver". Aviation, Space, and Environmental Medicine 67 (4): 308–13. PMID 8900980. 
  3. ^ Brubakk, A. O.; Neuman, T. S. (2003). Bennett and Elliott's physiology and medicine of diving, 5th Rev ed. United States: Saunders Ltd. ISBN 0-7020-2571-2. page needed
  4. ^ a b c Kay, E. "Prevention of middle ear barotrauma". Retrieved 2008-06-11. 
  5. ^ Kay, E. "The Diver's Ear - Under Pressure" (Flash video). Retrieved 2008-06-11. 
  6. ^ Roydhouse, N (1978). "The squeeze, the ear and prevention". South Pacific Underwater Medicine Society Journal 8 (1). ISSN 0813-1988. OCLC 16986801. Retrieved 2008-06-11. 
  7. ^ Taylor, D (1996). "The Valsalva Manoeuvre: A critical review". South Pacific Underwater Medicine Society Journal 26 (1). ISSN 0813-1988. OCLC 16986801. Retrieved 2008-06-11. 
  8. ^ Roydhouse, N and Taylor, D (1996). "The Valsalva Manoeuvre. (letter to editor)". South Pacific Underwater Medicine Society journal 26 (3). ISSN 0813-1988. OCLC 16986801. Retrieved 2008-06-11. 
  9. ^ Lim, SH; Anantharaman, V; Teo, WS; Goh, PP; Tan, ATH (1998). "Comparison of Treatment of Supraventricular Tachycardia by Valsalva Maneuver and Carotid Sinus Massage". Annals of Emergency Medicine 31 (1): 30–5. doi:10.1016/S0196-0644(98)70277-X. PMID 9437338. 
  10. ^ Nagappan, R; Arora, S; Winter, C (2002). "Potential dangers of the Valsalva maneuver and adenosine in paroxysmal supraventricular tachycardia--beware pre-excitation". Critical care and resuscitation 4 (2): 107–11. PMID 16573413. unreliable medical source?
  11. ^ Zuber, M.; Cuculi, F.; Oechslin, E.; Erne, P.; Jenni, R. (2008). "Is transesophageal echocardiography still necessary to exclude patent foramen ovale?". Scandinavian Cardiovascular Journal 42 (3): 222–5. doi:10.1080/14017430801932832. PMID 18569955. unreliable medical source?
  12. ^ Johnson, RH; Smith, AC; Spalding, JM (1969). "Blood pressure response to standing and to Valsalva's manoeuvre: Independence of the two mechanisms in neurological diseases including cervical cord lesions". Clinical Science 36 (1): 77–86. PMID 5783806. 
  13. ^ O'Shaughnessy, Michael. "Urinary incontinence, medical and surgical aspects". 
  14. ^ Bump, Richard C.; Mattiasson, Anders; Bø, Kari; Brubaker, Linda P.; Delancey, John O.L.; Klarskov, Peter; Shull, Bob L.; Smith, Anthony R.B. (1996). "The standardization of terminology of female pelvic organ prolapse and pelvic floor dysfunction". American Journal of Obstetrics and Gynecology 175 (1): 10–7. doi:10.1016/S0002-9378(96)70243-0. PMID 8694033. 
  15. ^ Gibran, S K; Kenawy, N; Wong, D; Hiscott, P (2007). "Changes in the retinal inner limiting membrane associated with Valsalva retinopathy". British Journal of Ophthalmology 91 (5): 701–2. doi:10.1136/bjo.2006.104935. PMC 1954736. PMID 17446519. 
  16. ^ "US astronaut grapples with 'tears in space'". spacedaily.com. 25 May 2011. Retrieved 27 May 2011. 
  17. ^ It's a Valsalva device, to equalize ears as pressure in suit increases Sam Cristoforetti on Twitter. 22 November 2011. Retrieved 22 November 2012.

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