Respiratory acidosis

Introduction to respiratory acidosis Respiratory acidosis refers to an increase in primary PaCO2 resulting in a decrease in pH. Clinically, the disease can exist alone or in combination with other acid-base balance disorders. According to the speed of onset, it can be divided into two categories: acute respiratory acidosis and chronic respiratory acidosis. The main reason is the lowering of the ventilation function of the lung; seen in respiratory obstruction, pneumonia, atelectasis, chest and abdomen surgery, trauma and so on. The fundamental method of treatment is to relieve the airway obstruction and improve the lung ventilation function. basic knowledge The proportion of illness: 0.06% Susceptible people: no specific population Mode of infection: non-infectious Complications: metabolic acidosis, sepsis, metabolic alkalosis, hyperkalemia

Causes of respiratory acidosis

Respiratory center inhibition (30%):

Some central nervous system diseases such as cerebral neoplasms, cerebral poliomyelitis, encephalitis, meningitis, vertebral artery embolism or thrombosis, increased intracranial pressure, traumatic brain injury, etc., respiratory center activity can be inhibited, Reduce ventilation and accumulate CO2. In addition, some drugs such as anesthetics, sedatives, sedatives (morphine, sodium barbital, etc.) have the effect of inhibiting breathing, and too much dose can cause hypoventilation. Carbonic anhydrase inhibitors such as acetazolamide can cause metabolic acidosis as described previously. It also inhibits carbonic anhydrase in red blood cells and reduces the release of CO ₂ from red blood cells in the lungs, causing an increase in arterial blood Pco ₂ . Patients with a tendency to acidosis should use this medicine with caution.

Respiratory nerves, muscle dysfunction (30%):

Found in poliomyelitis, acute infectious polyneuritis (Guillain-barre syndrome) botulism, myasthenia gravis, hypokalemia or familial periodic paralysis, high spinal cord injury. In severe cases, the respiratory muscles can be paralyzed. Abnormal thoracic thoracic abnormalities affecting respiratory movements include posterior scoliosis, scoliosis, Flail Chest, Ankylosing Spondylitis, and cardiopulmonary obesity syndrome (Picwick syndrome).

Extensive lung disease (20%):

It is the most common cause of respiratory acidosis. It includes chronic obstructive pulmonary disease, bronchial asthma, severe interstitial lung disease, and the like. These lesions can seriously impede alveolar ventilation. Excessive CO ₂ inhalation means that the concentration of CO _{2 in the} inhaled gas is too high, such as in a narrow space with poor ventilation such as tunnels and tanks. At this time, the alveolar ventilation did not decrease.

Respiratory acidosis prevention

Respiratory acidosis, mainly seen in respiratory obstruction and thoracic surgery or trauma, treatment to relieve airway obstruction, improve lung ventilation, chronic bronchitis, pneumonia and other medical diseases caused by respiratory insufficiency, respiratory acidosis is more common .

Respiratory acidosis complications Complications metabolic acidosis sepsis metabolic alkalosis hyperkalemia

1. Respiratory acidosis combined with metabolic acidosis showed PaCO ₂ , a significant increase and a significant decrease in HCO ₃ -. Due to the significant increase in the ratio of the two, severe acidosis was caused. The common causes are as follows:

In cardiac arrest, severe pulmonary edema is the most typical, salicylic acid poisoning plus sedative overuse and the original lung disease can also occur based on sepsis or renal failure.

During cardiac arrest or acute pulmonary edema, the lungs cannot discharge CO ₂ , causing a large accumulation of CO ₂ in the body, causing respiratory acidosis. When the circulation is disordered, the tissue cannot be perfused. Hypoxia leads to a large amount of lactic acid, which causes metabolic acidosis due to ventilation. Disorders and central lesions, PaCO ₂ value can not be reduced, so the pH value can be significantly reduced, treatment should be immediately cardiopulmonary resuscitation, recovery of airway patency, excessive infusion of NaHCO ₃ before ventilation is not smooth, for the reasons mentioned above, in addition, NaHCO ₃ Hyperosmotic hyperemia caused by injection and various changes such as promoting K+ from the outside of the cell can aggravate the risk of the lesion.

2, salicylic acid poisoning is mostly seen in elderly and suffering from joint pain, can produce chronic acidosis, when the use of sedatives or strong analgesics due to pain, can cause inhibition of the central nervous system caused by metabolic acidosis plus respiratory acidosis Chronic obstructive pulmonary disease can generally increase the hematocrit, increase the total oxygen carrying capacity, shift the oxygenated hemoglobin dissociation curve to the right, and compensatory to make the tissue oxygen supply normal, when combined with severe anemia, such as sudden digestion Hemorrhage, hypotension, arrhythmia, etc., can occur tissue hypoxia, increased lactic acid production, metabolic acidosis and respiratory acidosis, if combined with renal dysfunction, infection, etc., metabolic disorders are more serious, aggravated The extent of acidosis.

3, respiratory acidosis combined with metabolic alkalosis This is also a common type of mixed acid-base balance disorder, can be seen in chronic obstructive pulmonary disease with vomiting; chronic pulmonary heart disease in the presence of heart failure, use In the case of potassium-sparing diuretic treatment, the change of blood pH depends on the strength of acidosis and alkalosis. If the degree is appropriate, it will cancel each other and the pH will not change. If one side is strong, the pH will rise slightly. High or decreased; PaCO ₂ and plasma HCO ₃ - concentration increased significantly, and the degree of change of both exceeded the range that should be achieved by each other.

4, acute respiratory acidosis combined with hyperkalemia caused by ventricular fibrillation, 5% sodium bicarbonate 60 ~ 100ml, intravenously infused within 5 ~ 10min, so that K + transferred to the cells.

Symptoms of respiratory acidosis Common symptoms Respiratory failure Metabolic alkalosis Increased intracranial pressure Coma, shortness of breath, convulsions, Metabolic acidosis, Stupor edema, Drowsiness

1, difficulty breathing, lack of ventilation, fatigue, shortness of breath, cyanosis, headache, chest tightness.

2, blood pressure drops, sometimes sudden ventricular fibrillation.

3, sly, stupid, coma.

Examination of respiratory acidosis

1, blood gas analysis and detection, CO ₂ binding force detection.

2, blood electrolyte potassium, sodium, chlorine, calcium, magnesium detection.

3, liver, kidney function test.

4, ECG examination can appear arrhythmia.

5, according to clinical manifestations, the symptoms selected to do B-ultrasound, X-ray.

Diagnosis and identification of respiratory acidosis

diagnosis

The patient has a history of respiratory function, and some symptoms of respiratory acidosis, that is, respiratory fatigue acidosis should be suspected. In acute respiratory acidosis, blood gas analysis shows a significant decrease in blood pH, PCO _{2 is} increased, plasma [HCO ₃ -] is normal. When chronic respiratory acidosis occurs, the blood pH value does not decrease significantly, PCO ₂ increases, and plasma [HCO ₃ -] increases.

Diagnose based on

1. A history of respiratory function, such as respiratory obstruction, atelectasis, and pneumothorax.

2, difficulty breathing, shortness of breath, fatigue, cyanosis, headache, chest tightness, paralysis, coma.

3. Blood gas analysis showed that PACO ₂ increased and pH decreased.

Differential diagnosis

In addition to acute and chronic acidosis and acute respiratory acidosis based on chronic respiratory acidosis, aspiration acidosis requires a mixed acid-base balance disorder with metabolic acid-base balance and metabolic acid-base poisoning. Phase identification, generally through blood gas detection combined with etiological analysis and diagnosis is not difficult, but the acid and alkali in the body is constantly changing under normal conditions, acid and alkali maintain dynamic balance, the factors affecting acid-base changes in disease conditions are more complicated, such as pathological changes, Drugs and treatments, changes in the body's compensatory capacity, etc., especially respiratory acidosis, develop and change rapidly, so in some cases, the diagnosis and differential diagnosis of respiratory acidosis can also occur, due to respiratory The compensatory form of acidosis body is mainly the increase of renal secretion H+ and reabsorption of HCO ₃ -, especially in patients with chronic hypercapnia, the increase of PCO ₂ in the blood, HCO ₃ - is also significantly increased, when taking any effective treatment of enhanced ventilation After that, PaCO ₂ can be rapidly reduced and HCO ₃ - can not be rapidly reduced, resulting in a metabolic base after hypercapnia Toxic, that is, from respiratory acidosis to metabolic alkalosis.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.