Brief overview
- What is cyanosis? Bluish discoloration of skin and mucous membranes due to insufficient oxygen content in the blood. Typical are e.g. blue lips, earlobes, fingertips.
- Forms: peripheral cyanosis (due to increased oxygen depletion in the body periphery such as arms and legs), central cyanosis (due to insufficient oxygen loading of the blood in the lungs).
- Diagnosis: Initial interview, physical examination, blood tests, measurement of pulse and oxygen saturation in the blood by pulse oximetry, further examinations depending on the suspected cause of the cyanosis (e.g. ECG, cardiac ultrasound, lung function test).
- Treatment: Therapy of the underlying disease
- Attention: In case of acute cyanosis with shortness of breath/respiratory distress, dial emergency number 112 immediately and provide first aid!
Cyanosis: Definition
If the hemoglobin contains a lot of oxygen, the blood is bright red. If there is little oxygen, it becomes darker and looks bluish. This becomes visible on thin areas of skin, where the blood vessels running directly under the skin are most likely to show through. This explains, for example, the blue lips, earlobes and fingertips in cyanosis.
The bluish discoloration of skin and mucous membrane is the reason why cyanosis used to be called “cyanosis”.
Cyanosis: forms
- Central cyanosis: The lack of oxygen is of central origin – the blood flowing from the lungs to the periphery of the body is not sufficiently loaded with oxygen. Possible causes are, for example, lung diseases (pulmonary cyanosis) or heart defects (cardiac cyanosis).
If only the so-called body acra (nose, fingers, toes) are cyanotic, it is called acrocyanosis.
Cyanosis: Causes and development
The possible causes of cyanosis depend on whether peripheral or central cyanosis is present.
Peripheral cyanosis: Causes
Cold
To reduce heat loss, blood vessels contract in cold conditions. Blood flow in the periphery of the body slows down and thus decreases, which increases oxygen depletion. The first sign of this is usually blue lips, as the skin of the lips is particularly thin and translucent.
Thrombosis
If you suspect a thrombosis, you should consult a doctor immediately! A detached blood clot (thrombus) can block a lung vessel (pulmonary embolism), which can be life-threatening!
Blood changes
Another example of a blood change that can cause peripheral cyanosis is an excess of red blood cells (polyglobulia). It can slow down the blood flow.
Varicose Veins (Varicosis)
Varicose veins are signs of weak veins. Here, the blood pools in the deep or superficial leg veins and causes cyanosis.
Heart disease
Heart failure can develop, for example, as a result of narrowed heart valves (valvular stenosis) or cardiac arrhythmias.
Central cyanosis: Causes
Central cyanosis results from insufficient oxygenation of the blood. Causes include:
Pulmonary disease
Central cyanosis that develops due to lung disease is called pulmonary cyanosis. Its most common causes include:
- Asthma
- Chronic obstructive pulmonary disease (COPD): This chronic progressive lung disease causes coughing, shortness of breath and sputum.
- Pneumothorax (lung collapse): It occurs when air enters the pleural space (narrow space between the lung and the chest wall), such as in chest injuries. Typical symptoms are shortness of breath, cyanosis and shortness of breath.
- Pneumonia (lung inflammation)
Cardiac defect
Cardiac cyanosis occurs when, due to a heart defect, oxygen-poor blood is mixed with the oxygen-rich blood coming from the lungs before it flows further into the body periphery.
One heart defect that may be a cause of this is tetralogy of Fallot, for example. This is a congenital malformation of the heart and vessels close to the heart. It includes the following four defects:
- Right ventricular hypertrophy: tissue enlargement of the right side of the heart
- Ventricular septal defect: septum between right and left ventricle not completely closed
- aorta sitting directly above the ventricular septal defect, thus having contact with both ventricles
Poisonings
Poisoning with substances that inhibit gas exchange in the body can be manifested by cyanosis. These include, for example, poisonings with:
- Carbon dioxide
- Pesticides
- Opiates (psychoactive substances from the milky sap of the opium poppy)
- Oxygen deficiency at high altitudes (hypobaric hypoxia)
Cyanosis: diagnosis
If cyanosis is persistent and not caused by cold, you should see a doctor to have the cause clarified. This is especially true if you also suffer from acute shortness of breath, coughing and difficult breathing and/or physical weakness and rapid fatigability.
- How long has the cyanosis (e.g. bluish lips) been present?
- Do you have any other complaints besides cyanosis, such as shortness of breath or cough?
- Do you suffer from heart or lung disease?
- Are you taking any medications? If yes, which ones?
This is followed by a so-called visual diagnosis: the physician checks whether the lips, earlobes, mucous membranes, tip of the nose or fingernails are clearly discolored blue.
Blood tests are informative in the clarification of cyanosis: A blood count with analysis of the blood gases is performed. Important values are, for example, the number of red blood cells (erythrocytes), the hemoglobin content in the red blood cells and the oxygen content of the blood.
The Lewis test allows to distinguish between central and peripheral cyanosis: when massaging the earlobe it remains bluish discolored in central cyanosis, in peripheral cyanosis it becomes rosy.
Further examinations depend on what cause the physician suspects behind the cyanosis. If a heart disease is suspected, the following examinations, among others, can bring clarity:
- X-ray of the chest (chest X-ray)
- Electrocardiography (ECG)
- Cardiac catheterization
- Computer tomography (CT)
- Magnetic resonance imaging (MRI)
The physician detects possible lung diseases with a lung function test. This can detect asthma, bronchitis, COPD and other lung diseases.
Cyanosis: Treatment
In case of acute cyanosis, first aid is required! This is because the patient’s condition can become life-threatening.
Acute cyanosis: first aid
As a first responder, keep the following tips in mind:
- Make an emergency call: Dial 112 immediately!
- Mouth check: Check whether the patient has swallowed anything or whether there is still something in the mouth that he could swallow when breathing deeply, for example dentures. Remove the object in question.
- use asthma inhaler if necessary: Ask the person if they are asthmatic and have an asthma inhaler with them. This is because it could also be an asthma attack. If necessary, help the person to use the spray.
- Foreign body swallowed? Strong blows between the shoulder blades can help loosen a wedged foreign body. If this does not help, try the “Heimlich grip”: Hug the affected person from behind and place one fist on the upper abdomen below the breastbone. Now pull the fist jerkily in your direction with the other hand. Repeat the maneuver until the foreign body is spat out.
