Hyperventilation Syndrome/Breathing Pattern Disorders

Chapter 55 Hyperventilation Syndrome/Breathing Pattern Disorders





image Introduction



Hyperventilation Syndrome/Breathing Pattern Disorders Defined


Hyperventilation syndrome/breathing pattern disorders (HVS/BPDs) are described as follows:



As a direct result of HVS/BPDs, many patients present with multiple symptoms, some of which mimic serious disease. However, blood tests, electrocardiograms (ECGs), and thorough physical examinations may reveal nothing out of the ordinary. Up to 10% of patients in general internal medicine practice reportedly experience HVS/BPDs as their primary diagnosis.2 Many individuals with HVS/BPDs experience severe and genuinely distressing symptoms, and considerable medical expenses are incurred in excluding more serious pathology.



Gender


More females than males have HVS/BPDs, ranging from a ratio of 2:1 to 7:1. The peak age of incidence is 15 to 55 years, although other ages can be affected.2 Women may be more at risk because of hormonal influences, because progesterone stimulates respiratory rate, and in the luteal (postovulation/premenstrual) phase, CO2 levels drop on average 25%. Additional stress can then “increase ventilation at a time when CO2 levels are already low.”3 A case report linked progesterone (medroxyprogesterone) therapy as a cause of hyperventilation in a 52-year-old menopausal woman.4







Pathophysiology



Physiologic and Pathophysiologic Causes of Altered Patterns of Breathing


Hyperventilation can be an appropriate physiologic response to the body’s metabolic needs; for example, tachypnea (rapid breathing) or hyperpnea (increase in respiratory rate proportional to increase in metabolism) may result as the respiratory centers respond automatically and appropriately to rising CO2 production due to exercise or organic disease that may be creating acidosis. It is therefore important to exclude organic causes that diminish PaO2 or elevate PaCO2 levels.6


Organic causes of HVS/BPDs that should be excluded and/or identified before breathing rehabilitation is initiated include the following:



BPDs may also emerge from a background of established pathology (e.g., asthma, cardiovascular disease, kidney failure, chronic pain). Even tumor infiltrates into brain respiratory centers and central chemoreceptors have caused hyperventilation.8 Where this is the case, the aim of this chapter is not to explore these states, since they are discussed elsewhere in this textbook.


Fluctuating blood glucose levels may trigger HVS/BPD symptoms in patients with high carbohydrate diets, which produce rapid rises followed by sharp falls to fasting levels or below.6,9


Chaitow et al10 noted that the following factors could lead to altered breathing patterns through pH shifts:








Oxygen Delivery and Smooth Muscle Constriction


The blood carries oxygen mainly in molecules of hemoglobin, which are contained in red blood cells. In an appropriate environment, hemoglobin combines readily with oxygen (to form oxyhemoglobin). This process varies according to local pH, as well as PO2. This ability to combine is important for both absorbing oxygen through the alveoli and also for releasing oxygen through the capillary walls, where oxygen diffuses into the tissues.


These two properties are largely determined by local conditions, so that when pH is low (i.e., the blood is more acidic), hemoglobin in that area is stimulated to release additional oxygen. This is true of metabolically active tissues in general but especially of muscles. An exercising muscle needs all the oxygen it can get, and this is assisted by its chemical nature, explained by West as follows:


An exercising muscle is acid, hypercarbic, and hot, and it benefits from increased unloading of oxygen from its capillaries.11


The effect of pH on oxyhemoglobin dissociation is called the Bohr effect.


In the lungs the need is to bind oxygen to hemoglobin, not release it. Not surprisingly, the lungs have a more alkaline environment.


The fact that a shift of the blood toward acidity promotes dissociation and release of oxygen from the hemoglobin is particularly important when considering hyperventilation, because the resulting alkalinity causes the hemoglobin molecule to retain more oxygen than usual. With increased alkalinity encouraging smooth muscle contraction and therefore diminished diameter of blood vessels, as well as the reluctance of hemoglobin to release its oxygen, a relative oxygen deficit is likely in tissues and the brain, leading to symptoms such as fatigue, aching, cramping, and cognitive problems.



Psychology and Hyperventilation Syndrome/Breathing Pattern Disorders


On a psychological level, Bradley14 described a “cascade of symptoms” (see Figure 55-1) in which an original cause (emotional or physical) leads to tension and anxiety that results in hyperventilation, possibly an acute hyperventilation attack, which (with repetition) over time, results in anticipation, anxiety, and avoidance behaviors or phobias, or both.



Chaitow et al10 described aspects of the influence of emotion on breathing1517:


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Sep 12, 2016 | Posted by in MANUAL THERAPIST | Comments Off on Hyperventilation Syndrome/Breathing Pattern Disorders

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