Cyanosis pathophysiology: Difference between revisions
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***Low [[cardiac output]] | ***Low [[cardiac output]] | ||
***Vasomotor instability | ***Vasomotor instability | ||
*Factors can affect the development of [[cyanosis]]: | |||
**[[Hemoglobin]] concentration | |||
**[[Human skin color|Skin pigmentation]] | |||
**Presence of abnormal [[Hemoglobin|hemoglobins]] interfering with [[oxygen]] [[Chemical affinity|affinity]] | |||
**Lighting conditions | |||
Revision as of 00:12, 9 March 2018
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Chandrakala Yannam, MD [2]
Overview
Cyanosis is a bluish or purplish discoloration of skin and mucous membranes. Two mechanisms involved in the development of cyanosis, Systemic arterial oxygen desaturation and increased oxygen absorption by tissues. Cyanosis is evident when arterial oxygen desaturation falls below 85% or the concentration of deoxygenated hemoglobin (Hb) is below 5 gm/dl. Several factors can affect the appearance of cyanosis includes skin pigmentation, Hemoglobin (Hb) levels, oxygen affinity to the hemoglobin (Hb).
Pathophysiology
- Cyanosis is a bluish or purplish discoloration of the skin and mucous membranes.
- Appearance of cyanosis depends on the absolute amount of deoxygenated hemoglobin(Hb) present in the blood rather than the ratio of reduced hemoglobin (Hb) to oxygenated hemoglobin (Hb).[1][2]
- Physiologically, arterial hemoglobin desaturation can be caused by following mechanisms in the person who breathes room air at normal altitude:
- Alveolar hypoventilation
- Diffusion impairment
- Mismatch of ventilation and perfusion
- Right-to-left shunting
- Inadequate oxygen transport by hemoglobin
- According to Lundsgaard and Van Slyke (1923), as well as subsequent investigators, cyanosis is evident when the subpapillary capillaries contain from 4 to 6 gm/dl of deoxygenated hemoglobin and oxygenation of hemoglobin or oxygen saturation falls below 85% (normal ABG PaO2 85-100%).[3][4]
- Cyanosis occurs due to following mechanisms:
- Central cyanosis:[7]
- Central cyanosis is caused by reduced arterial oxygen saturation or the presence of abnormal hemoglobin derivatives (methemoglobin or sulfhemoglobin).[8][9][10][11]
- Central cyanosis is evident when the systemic arterial deoxygenated hemoglobin concentration in the blood exceeds 5 g/dL (oxygen saturation ≤85 percent).[12][13]
- The increased amount of deoxygenated hemoglobin is the result of either increased amount of venous admixture or reduced capillary arterial oxygen tension.
- Peripheral cyanosis:[14][15]
- In peripheral cyanosis, systemic arterial oxygen saturation is normal.
- Increased oxygen extraction by tissues causes wide systemic arteriovenous oxygen difference and increased deoxygenated blood on the venous side of the capillary beds.
- The increased oxygen extraction by tissues results from the sluggish movement of blood through the capillary circulation.
- Causes for reduced blood flow through capillary circulation include:
- Vasoconstriction caused by exposure to cold
- Venous obstruction
- Elevated venous pressure
- Hyperviscosity (Polycythemia)
- Low cardiac output
- Vasomotor instability
- Factors can affect the development of cyanosis:
- Hemoglobin concentration
- Skin pigmentation
- Presence of abnormal hemoglobins interfering with oxygen affinity
- Lighting conditions
Genetics, Associated Conditions, Gross Pathology, Microscopic Pathology
For the detailed information of the genetics, associated conditions, gross and microscopic pathological features associated with conditions causing cyanosis, click the links below.
- Tetralogy of Fallot
- Tricuspid atresia
- Ebstein's anomaly
- Tricuspid stenosis
- Transposition of great arteries (TGA)
- Pulmonary stenosis
- Truncus arteriosus
- TAPVC
- Coarctation of aorta
- Aortic stenosis
- Eisenmenger's syndrome
- HLHS (Spectrum of hypoplastic left heart syndrome)
- Left-sided heart failure
- Acute chest syndrome
- Pneumothorax
- Foreign body aspiration
- Carbon monoxide poisoning
- Hydrogen cyanide poisoning
- Croup
- Bacterial tracheitis
- Hemothorax
- Pneumonia
- Asthma
- COPD
- Bronchiolitis
- Respiratory distress syndrome (Hyaline membrane disease)
- Empyema
- Pleural effusion
- Cystic fibrosis
- Atelectasis
- Bronchopulmonary dysplasia
- Alveolar capillary dysplasia
- Pulmonary embolism
- Pulmonary hypertension
- High Altitude
- Intracranial hemorrhage
- Seizures
- Choanal atresia
- Micrognathia or retrognathia
- Laryngomalacia
- Congenital diaphragmatic hernia
- Myasthenia gravis
- Apnea of prematurity
- Obstructive sleep apnea
- Pulmonary edema
- Pulmonary hemorrhage
- Pulmonary arteriovenous malformation
- Methemoglobinemia (congenital or acquired)
- Sulfhemoglobinemia
- Polycythemia vera
- Disseminated intravascular coagulation
- Shock
- Sepsis
- Amniotic fluid embolism
- Cold exposure
- Acrocyanosis
- Raynaud's phenomenon
- Raynaud's disease
- Peripheral vascular disease
- Buergers disease
- Deep vein thrombosis
- Superior vena cava syndrome
References
- ↑ Blount SG (May 1971). "Cyanosis: pathophysiology and differential diagnosis". Prog Cardiovasc Dis. 13 (6): 595–605. PMID 4933007.
- ↑ GERACI JE, WOOD EH (July 1951). "The relationship of the arterial oxygen saturation to cyanosis". Med. Clin. North Am. 1: 1185–1202. PMID 13098533.
- ↑ Lundsgaard C (September 1919). "STUDIES ON CYANOSIS : I. PRIMARY CAUSES OF CYANOSIS". J. Exp. Med. 30 (3): 259–69. PMC 2126682. PMID 19868357.
- ↑ Snider HL, Roy TM (October 1988). "Deoxyhaemoglobin concentrations in the detection of central cyanosis". Thorax. 43 (10): 801. PMC 461518. PMID 3206391.
- ↑ Adeyinka A, Kondamudi NP. PMID 29489181. Missing or empty
|title=(help) - ↑ Lundsgaard C (September 1919). "STUDIES ON CYANOSIS : II. SECONDARY CAUSES OF CYANOSIS". J. Exp. Med. 30 (3): 271–93. PMC 2126678. PMID 19868358.
- ↑ Steinhorn RH (September 2008). "Evaluation and management of the cyanotic neonate". Clin Pediatr Emerg Med. 9 (3): 169–175. doi:10.1016/j.cpem.2008.06.006. PMC 2598396. PMID 19727322.
- ↑ Whelan JF (May 1984). "Methemoglobin as a cause of cyanosis". Can Med Assoc J. 130 (10): 1260. PMC 1483499. PMID 6722683.
- ↑ Ananthakrishna R, Moorthy N, Rao DP, Nanjappa MC (2015). "An adult with central cyanosis and differential pulmonary vascularity". Ann Pediatr Cardiol. 8 (3): 253–4. doi:10.4103/0974-2069.150701. PMC 4608209. PMID 26556978.
- ↑ Stadie WC (September 1919). "THE OXYGEN OF THE ARTERIAL AND VENOUS BLOOD IN PNEUMONIA AND ITS RELATION TO CYANOSIS". J. Exp. Med. 30 (3): 215–40. PMC 2126679. PMID 19868355.
- ↑ Bailliard F, Anderson RH (January 2009). "Tetralogy of Fallot". Orphanet J Rare Dis. 4: 2. doi:10.1186/1750-1172-4-2. PMC 2651859. PMID 19144126.
- ↑ Martins P, Castela E (October 2008). "Transposition of the great arteries". Orphanet J Rare Dis. 3: 27. doi:10.1186/1750-1172-3-27. PMC 2577629. PMID 18851735.
- ↑ Jain A, Patel A, Hoppe IC (2016). "Benzocaine-Induced Cyanosis". Eplasty. 16: ic18. PMC 4879862. PMID 27257469.
- ↑ Baranoski G, Van Leeuwen SR, Chen TF (July 2017). "On the detection of peripheral cyanosis in individuals with distinct levels of cutaneous pigmentation". Conf Proc IEEE Eng Med Biol Soc. 2017: 4260–4264. doi:10.1109/EMBC.2017.8037797. PMID 29060838. Vancouver style error: initials (help)
- ↑ Das S, Maiti A (November 2013). "Acrocyanosis: an overview". Indian J Dermatol. 58 (6): 417–20. doi:10.4103/0019-5154.119946. PMC 3827510. PMID 24249890.