VALSALVA MANEUVER Flashcards
Valsalva Maneuver
forced expiration against a closed glottis and nose
occurs in coughing, defecation, and heavy lifting
What Happens During Valsalva Maneuver?
changes in blood pressure and pulse occurs in response to the brief periods of strain
Normal Breathing
involves inspiration and expiration
there is already pressure (3-5 mm)
How Much Pressure Occurs in the Valsalva Maneuver?
increases to 150 mmHg when glottis is closed
3 Factors that Affect Valsalva Maneuver
baroreceptors
sympathetic
parasympathetic
Baroreceptors
abundant in the bifurcation of the aorta and internal carotid arteries
sensitive to stretch of vessels
triggered by stretch receptors
enables homeostasis
is activated during phase 2 (strain phase)
Parasympathetic
activated during phase 1 and 4
lowers HR
vagus nerve stimulation
Sympathetic
activated during phase 2
increases heart rate and systemic vascular resistance
Response of HR and BP During Valsalva Maneuver
was discovered by Antonio Valsalva
valsalva is used by astronauts, divers, heavy lifters
Why Can’t Patients with Stroke Conduct Valsalva Maneuver?
there is not enough blood supply in the brain
Implications in PT Practice and What PT’s Do To Prevent Maneuver
tell pt to count 1-10 to ensure that they are breathing
recommended for those with high HP (supraventricular tachycardia/ SVT) to slow down HR
Why Do Athletes Have Lower Resting HR
they have a larger stroke volume; less energy is used with fewer contractions; more efficient pumps into the systemic circulation
Phases of the Valsalva Maneuver
Early Valsalva/ Initial Phase
Strain Phase
Release Phase
Overstretched Phase
Early Valsalva/ Initial Phase
increased intrathoracic pressure/ intra abdominal pressure
increased blood pressure
decreased venous return / decreased to no change in HR
increased stroke volume
increased intracranial pressure
blood from the heart travels to the upper extremities
pressure in the abdominal and chest cavity
stimulation of parasympathetic NS signals the brain to decrease pressure= decrease HR
Strain Phase
increased intrathoracic pressure/ intra-abdominal pressure
decreased blood pressure
increased heart rate= tachycardia (compensates for the lack of stroke volume) = reduced parasympathetic= increased sympathetic activity
decreased stroke volume= increased vasoconstriction
increased intracranial pressure
return to systematic blood
Release Phase
decreased intrathoracic pressure/ intra-abdominal pressure
decreased blood pressure
increased heart rate
increase stroke volume
increased intracranial pressure
where pt will feel dizzy/ lightheaded
Overstretched Phase
decreased intrathoracic and intra-abdominal pressure
increased blood pressure
decreased heart rate
increased stroke volume
baroreceptors detects increase in cardiac output –> signals the brain –> brain sends signals to parasympathetic NS (via vagus nerve) —> blood vessels vasodilate –> decrease in HR –> decrease aortic pressure
