Pulmonary encephalopathy in the elderly
Introduction
Introduction to pulmonary encephalopathy in the elderly Pulmonary encephalopathy refers to a syndrome of psycho-neuropathic symptoms caused by lung, bronchi, and chest diseases caused by hypoxia and carbon dioxide retention, such as those that exclude other causes. basic knowledge The proportion of illness: 0.0065% Susceptible people: the elderly Mode of infection: non-infectious Complications: optic disc edema, coma, cerebral palsy, pulmonary encephalopathy
Cause
Causes of pulmonary encephalopathy in the elderly
(1) Causes of the disease
Chronic obstructive pulmonary disease is the main underlying cause of pulmonary encephalopathy, of which 85% is caused by chronic pulmonary heart disease. Common causes of pulmonary encephalopathy are:
1 acute respiratory and pulmonary infections, severe bronchospasm, sputum occlusion in the airway, so that the previously impaired lung ventilation function is further reduced to cause CO2 retention in the body.
2 iatrogenic factors, such as improper application of sedatives, high concentration of oxygen, leading to respiratory depression and increased CO2 anesthesia; inappropriate application of dehydrating agents and diuretics, causing sputum viscous and aggravating airway obstruction.
3 Chronic obstructive pulmonary disease with right heart failure, due to decreased brain blood volume, aggravation of cerebral hypoxia and cerebral metabolic disorders.
(two) pathogenesis
1. The effect of carbon dioxide on the brain
Carbon dioxide is the main regulator of cerebral blood flow. When PaCO2 is increased, cerebral vasodilation increases cerebral blood flow, increases vascular permeability, leads to increased intracranial pressure and cerebral edema, and excessively high PaCO2 has anesthesia similar to laughing gas (N2O). Role, causing coma.
2. Brain cell acidosis
Clinically, PaCO2 has reached a fairly high level, and symptoms of pulmonary cerebral encephalopathy still do not occur. However, if the pH of the cerebrospinal fluid is lowered, neuropsychiatric symptoms occur rapidly, and hypercapnia in respiratory failure leads to hydrogen ion concentration in the blood. Increase, when the blood buffer exceeds the regulation capacity and the compensation range of the kidney, causing blood pH drop and respiratory acidosis, excessive hydrogen ions in the blood slowly enter the cerebrospinal fluid through the blood-brain barrier, and the pH value of the cerebrospinal fluid Decreased, the concentration of hydrogen ions in brain cells increases, leading to acidosis of brain tissue.
3. The effect of hypoxia on brain cells
Hypoxia can lead to anaerobic metabolism of brain cells, resulting in non-volatile acidosis and metabolic acidosis. Severe hypoxia can affect the function of brain cells and even cause irreversible damage and death of brain cells.
Prevention
Elderly patients with pulmonary encephalopathy prevention
Breathing exercises to improve the body's immunity. Strengthen safety protection, transfer patients to a safe room, avoid the window to avoid accidents, remove unnecessary equipment and dangerous items such as hot water bottles, knives, scissors, and ropes to avoid injury and self-injury.
Complication
Elderly patients with pulmonary encephalopathy Complications, optic disc edema, cerebral palsy, encephalopathy
Mainly complicated by optic disc edema, coma, cerebral palsy formation.
Symptom
Symptoms of pulmonary encephalopathy in the elderly Common symptoms Drowsiness, apathy, fluttering, tremor, respiratory failure, coma, convulsion, metabolic alkalosis
On the basis of the clinical manifestations of underlying diseases and respiratory failure, there is apathy, muscle tremor or flapping tremor, intermittent convulsions, lethargy, and even coma, etc., or sputum reflexes may be weakened or disappeared, and pyramidal tract signs are positive, etc. Cerebrovascular disease, metabolic alkalosis, infection with toxic encephalopathy.
Examine
Examination of elderly patients with pulmonary encephalopathy
Blood gas analysis: PaO2<60mmHg, with partial pressure of carbon dioxide>50mmHg, the pH change is not as obvious as that of PaCO2. The actual pH depends on the ratio of bicarbonate to PaO2. When PaCO2 is increased, but the pH is 7.35, it is called compensatory. Respiratory acidosis, such as pH <7.35, is called decompensated respiratory acidosis. Another common clinical condition is that the patient underwent arterial blood gas analysis under oxygen inhalation, PaCO2 increased, but PaO2>60mmHg, This is the performance of type II respiratory failure after oxygen absorption.
Chest radiographs suggest pulmonary infection or lung occupying lesions.
Diagnosis
Diagnosis and differential diagnosis of pulmonary encephalopathy in the elderly
diagnosis
According to the history of chronic brain and lung disease, clinical neuropsychiatric symptoms can be diagnosed in combination with blood gas analysis.
Differential diagnosis
Must be differentiated from infectious toxic encephalopathy, severe electrolyte imbalance, cerebral hemorrhage, DIC, and cerebral arteriosclerosis.
