Cyanosis
Cyanosis | |
---|---|
low oxygen saturations | |
Specialty | Pulmonology, cardiology |
Types | Central, peripheral |
Cyanosis is the change of body
Cyanosis is further classified into central cyanosis and peripheral cyanosis.
Pathophysiology
The mechanism behind cyanosis is different depending on whether it is central or peripheral.
Central cyanosis
Central cyanosis occurs due to decrease in
Causes of central cyanosis are discussed below.
Peripheral cyanosis
Peripheral cyanosis happens when there is increased concentration of
Causes
Central cyanosis
Central cyanosis is often due to a circulatory or ventilatory problem that leads to poor blood
Acute cyanosis can be a result of
that ventilation is being blocked.Central cyanosis may be due to the following causes:
- Central nervous system (impairing normal ventilation):[6]
- Respiratory system:[1][6]
- Pneumonia
- Bronchiolitis
- Bronchospasm (e.g., asthma)
- Pulmonary hypertension
- Pulmonary embolism
- Hypoventilation
- Chronic obstructive pulmonary disease, or COPD (emphysema)[6]
- Cardiovascular system:[1][6]
- Congenital heart disease (e.g., Tetralogy of Fallot, right to left shunts in heart or great vessels)
- Heart failure
- Valvular heart disease
- Myocardial infarction
- Hemoglobinopathies:[6]
- Methemoglobinemia [a]
- Sulfhemoglobinemia [b]
- Polycythemia
- oxyhaemoglobin) creating a permanent T-state of Hb..
- Others:
- High altitude, cyanosis may develop in ascents to altitudes >2400 m.[1][6]
- Hypothermia[6]
- Frostbite[8]
- Obstructive sleep apnea[6]
- ^ Note this causes "spurious" cyanosis, in that, since methemoglobin appears blue, the patient can appear cyanosed even in the presence of a normal arterial oxygen level.
- ^ Note a rare condition in which there is excess sulfhemoglobin (SulfHb) in the blood. The pigment is a greenish derivative of hemoglobin which cannot be converted back to normal, functional hemoglobin. It causes cyanosis even at low blood levels.
Peripheral cyanosis
Peripheral cyanosis is the blue tint in fingers or extremities, due to an inadequate or obstructed circulation.[6] The blood reaching the extremities is not oxygen-rich and when viewed through the skin a combination of factors can lead to the appearance of a blue color. All factors contributing to central cyanosis can also cause peripheral symptoms to appear, but peripheral cyanosis can be observed in the absence of heart or lung failures.[6] Small blood vessels may be restricted and can be treated by increasing the normal oxygenation level of the blood.[6]
Peripheral cyanosis may be due to the following causes:[6]
- All common causes of central cyanosis
- Reduced cardiac output (e.g., heart failure or hypovolemia)
- Cold exposure
- Chronic obstructive pulmonary disease (COPD)
- Arterial obstruction (e.g., Raynaud phenomenon)
- Venous obstruction (e.g., deep vein thrombosis)
Differential cyanosis
Evaluation
A detailed history and
In
It is important to note that
Management
Cyanosis is a
If it is an emergency, management should always begin with securing the
If the methemoglobin levels are positive for methemoglobinemia, first-line treatment is to administer methylene blue.[1]
History
The name cyanosis literally means the blue disease or the blue condition. It is derived from the color cyan, which comes from cyanós (κυανός), the Greek word for blue.[13]
It is postulated by Dr. Christen Lundsgaard that cyanosis was first described in 1749 by
See also
- Acrocyanosis
- Blue baby syndrome
- Raynaud's phenomenon
- Blue Fugates
References
- ^ PMID 29489181, retrieved 2021-10-28
- S2CID 22892985.
- PMID 15275979.
- ^ Mini Oxford Handbook of Clinical Medicine (7th ed.). p. 56.
- PMID 29489181, retrieved 2023-09-24
- ^ )
- ^ S2CID 244083635.
- PMID 30725599.
- ^ PMID 28613509, retrieved 2021-11-19
- ^ PMID 5502102.
- ISBN 9789350259450, retrieved 2021-11-05
- PMID 15275985.
- Mosby's Medical, Nursing & Allied Health Dictionary. Mosby-Year Book (4th ed.). 1994. p. 425.
- ^ PMID 19868357.