Asthma is a chronic lung disease that is characterized by periods of bronchospasm, in which the airways within the lungs constrict and are unable to deliver oxygen correctly. Hypoxia is defined by "Mosby's Medical Dictionary" as an insufficient amount of oxygen at the level of the body's cells. Without enough oxygen to carry to the organs of the body, a variety of symptoms may occur.
Shortness of Breath
Patients who are having an episode of airway obstruction will have varying degrees of breathlessness, depending on the severity of the episode, or exacerbation. In mild cases, a patient will have some shortness of breath while walking, but will feel more comfortable while sitting and resting. In more severe cases, the hypoxia associated with asthma may be seen in shortness of breath that the patient experiences even while resting. Finally, according to Dr. Christopher Fanta, writing in UpToDate, a patient may be so out of breath that she is unable to lie down and must remain sitting.
Increased Heart Rate
Another indication that oxygen delivery is impaired is tachycardia--an increase in the rate at which the heart beats. The normal pulse is fewer than 100 beats per minute. In severe asthma attacks, according to the National Institutes of Health website MedlinePlus, the heart rate may be increased to over 100 beats per minute.
Change in Level of Alertness
Because the brain is so sensitive to the levels of oxygen that are available, changes in the level of alertness are also indicators that a patient with asthma is suffering the effects of hypoxia. Similarly to other symptoms, the degree of severity is related to the degree of the exacerbation. In mild asthma, for example, a patient may seem more agitated than usual. Patients who are having a severe asthma attack may become either confused or extremely drowsy. According to Drs. Mark Graber and Eric Dickson, writing in UpToDate, these are signs that the patient is suffering from severe levels of hypoxia; complete respiratory failure may soon follow.
References
- The Free Dictionary
- "UpToDate;" Acute asthma exacerbations in children: Outpatient management; R. Scarfone; May 2010
- "UpToDate;" Evaluation of the adult with dyspnea in the emergency department; M. Graber and E. Dickson; September 2009
- Asthma
