At rest, an average 70 kg person breathes 12 to 15 times a minute with a tidal volume of about 600 ml. Spontaneous respiration is controlled by neural and chemical mechanisms. Does he develop coughing or wheezing in the recumbent position? Did he ever wake up at night with shortness of breath? How long after lying down did the episode occur, and what did he do to relieve his distress? Characteristically, the patient with left ventricular failure sits up at bedside, dangles his feet, and refrains from ambulation or other activity that is likely to worsen his symptoms. Inquire about the number of pillows he uses under his head at night and whether he has ever had to sleep sitting up. The degree of functional impairment can be assessed in this manner.Īdditional questions should be aimed at ascertaining whether the patient has orthopnea or paroxysmal nocturnal dyspnea. It is helpful to ask if he has noticed any recent or progressive limitation in his ability to conduct specific tasks that he was able to perform without difficulty in the past (e.g., walking, climbing stairs, performing household chores).

Dyspnea on exertion would be abnormal if it occurred with activity that is normally well tolerated by the patient. The level of activity tolerated by any individual depends on such variables as age, sex, body weight, physical conditioning, attitude, and emotional motivation. Normal persons may feel dyspneic with strenuous exercise. Sometimes a nonproductive cough may be present as a 'dyspnea equivalent.' What other significant medical problems does the patient have, and what medications has he been taking? How much has he smoked?ĭyspnea on exertion is by no means always indicative of disease. Ask about associated symptoms: chest pain, palpitations, wheezing, or coughing. Response to activity, emotional state, and change of body position should be noted. The conditions in which dyspnea occurs should be ascertained. When did it begin? Has the onset been sudden or insidious? Inquire about the frequency and duration of attacks. Begin with a nonleading question: Do you have any difficulty breathing? If the response is affirmative and dyspnea is established as a problem, it should be characterized in detail. Platypnea refers to breathlessness that occurs in the upright position and is relieved with recumbency.Ī patient with dyspnea may say: 'I feel short of breath,' 'I'm having difficulty breathing,' 'I can't catch my breath,' 'I feel like I'm suffocating.' Because it is a subjective phenomenon, the perception of dyspnea and its interpretation vary from patient to patient. Trepopnea is dyspnea that occurs in one lateral decubitus position as opposed to the other. Two uncommon types of breathlessness are trepopnea and platypnea. Paroxysmal nocturnal dyspnea (PND) is a sensation of shortness of breath that awakens the patient, often after 1 or 2 hours of sleep, and is usually relieved in the upright position. Orthopnea is the sensation of breathlessness in the recumbent position, relieved by sitting or standing. These conditions may not always be associated with dyspnea. Tachypnea is an increase in the respiratory rate above normal hyperventilation is increased minute ventilation relative to metabolic need, and hyperpnea is a disproportionate rise in minute ventilation relative to an increase in metabolic level. Dyspnea should be differentiated from tachypnea, hyperventilation, and hyperpnea, which refer to respiratory variations regardless of the patients' subjective sensations.

Dyspnea on exertion (DOE) may occur normally, but is considered indicative of disease when it occurs at a level of activity that is usually well tolerated.

It is a subjective experience perceived and reported by an affected patient. Dyspnea refers to the sensation of difficult or uncomfortable breathing.

Nocturn catch