上海交通大学：《诊断学》课程PPT教学课件（英语版）Chapter 8 Dyspnea

Dyspnea

Dyspnea

Definition Dyspnea is defined as an awareness of difficulty in breathing It is therefore a symptom, usually described by the patient as shortness of breath, whether the sensation is due to actual difficulty in breathing or is essentially an awareness of hyperventilation. If the symptom becomes striking, it always companies with dilatation of nares cyanosis, use of accessory muscles of respiration and abnormalities of respiratory rate, depth or rhythm

Definition: Dyspnea is defined as an awareness of difficulty in breathing It is therefore a symptom, usually described by the patient as “shortness of breath,” whether the sensation is due to actual difficulty in breathing or is essentially an awareness of hyperventilation. If the symptom becomes striking, it always companies with dilatation of nares, cyanosis, use of accessory muscles of respiration and abnormalities of respiratory rate, depth or rhythm

Etiology Respiratory diseases Circulatory diseases Poisoning Hematology Neuropsychogenic factors

Etiology • Respiratory diseases • Circulatory diseases • Poisoning • Hematology • Neuropsychogenic factors

Mechanism clinical feature Respiratory dyspnea 1. Inspiratory dyspnea 2. Expiratory dyspnea 3. Mixed dyspnea

Mechanism & clinical feature • Respiratory dyspnea 1. Inspiratory dyspnea 2. Expiratory dyspnea 3. Mixed dyspnea

Mechanism clinical feature Cardiac dyspnea Cardiac dyspnea is usually attributable to pulmonary vascular congestion resulting from the left and/or right heart failure

Mechanism & clinical feature • Cardiac dyspnea Cardiac dyspnea is usually attributable to pulmonary vascular congestion resulting from the left and/or right heart failure

Mechanism clinical feature Toxic dyspnea In the metabolic acidosis (uremia and diabetic ketosis), the acid metabolites stimulate the respiratory center, causing deep and regular respiration with snoring The overdose of morphine and pentobarbital can depress respiratory center causing deep respiration or Cheyne-Stokess respiration

Mechanism & clinical feature • Toxic dyspnea In the metabolic acidosis (uremia and diabetic ketosis), the acid metabolites stimulate the respiratory center, causing deep and regular respiration with snoring. The overdose of morphine and pentobarbital can depress respiratory center causing deep respiration or Cheyne-Stokess respiration

Mechanism clinical feature Hematologic dyspnea In severe anemia, sulf hemoglobinemia methaemoglobinemia or carbon monoxide poisoning the decrease of oxygen-carrying capacity and oxygen content develop abnormal respiration and increased heart rate. The respiration rate also increases in shock which stimulates respiration center because of hypotension

Mechanism & clinical feature • Hematologic dyspnea In severe anemia, sulf hemoglobinemia, methaemoglobinemia or carbon monoxide poisoning the decrease of oxygen-carrying capacity and oxygen content develop abnormal respiration and increased heart rate. The respiration rate also increases in shock which stimulates respiration center because of hypotension

Mechanism clinical feature Neuro-psychogenic dyspnea Dyspnea may occur in the patients suffering from cerebrovascular diseases (intracranial hemorrhage, elevated intracerebral pressure). The respiratory center loses the blood supply or is compressed. The respiration becomes deep, slow and irregular. In some cases the dyspnea may be psychogenic which is characterized by repetitive deep, sighing respiration with numbness of extremities or lips, cheiropedal spasm These are also manifestations of acute respiratory alkalosis

Mechanism & clinical feature • Neuro-psychogenic dyspnea Dyspnea may occur in the patients suffering from cerebrovascular diseases (intracranial hemorrhage, elevated intracerebral pressure). The respiratory center loses the blood supply or is compressed. The respiration becomes deep, slow and irregular. In some cases the dyspnea may be psychogenic, which is characterized by repetitive deep, sighing respiration with numbness of extremities or lips, cheiropedal spasm. These are also manifestations of acute respiratory alkalosis

Accompanied Symptom Paroxysmal dyspnea with wheezing Dyspnea with chest pain Dyspnea with fever Dyspnea with cough and purulent sputum Dyspnea with coma

Accompanied Symptom • Paroxysmal dyspnea with wheezing. • Dyspnea with chest pain. • Dyspnea with fever. • Dyspnea with cough and purulent sputum. • Dyspnea with coma