cyanosis,definition,causes,differences between central and peripheral cyanosis,approach to cyanosis

1. CYANOSIS
Dr.G.VENKATA RAMANA
MBBS DNB FAMILY MEDICINE

2. • Definition
• Bluish color of the skin and mucous membranes resulting
from an increased quantity of reduced hemoglobin (i.e.,
deoxygenated hemoglobin) or of hemoglobin derivatives
(e.g., methemoglobin or sulfhemoglobin) in the small blood
vessels of those tissues
• Criteria
• Deoxy Hb >5 g% or abnormal Hb (metHb or sulf Hb) ±
SaO2 <85%.
• Classification
• True cyanosis
• Central cyanosis
• Peripheral cyanosis
• Mixed cyanosis
• Pseudocyanosis

4. pPseudocyanosis
• Pseudocyanosis
• Metals Gold, Silver, Mercury, Arsenic
• Drugs Minocycline, Chloroquine, Amiodarone
• Differential cyanosis
• Cyanosis is seen in only lower limbs PDA with
eisenmengerization
• Reverse differential cyanosis
• Cyanosis is seen in only upper limbs PDA with
eisenmengerization and transposition of great arteries
• Three by four cyanosis
• In addition to lower limbs, the left upper limb may also be
cyanosed, when the patent ductus opens proximal to the
origin of left subclavian artery

5. • Intermittent cyanosis
• Seen in Ebstein’s anomaly
• Cyclical cyanosis
• Bilateral choanal atresia
• Orthocyanosis
• Development of cyanosis only in upright position due to
hypoxia occurring in erect posture Seen in pulmonary
arteriovenous malformation
• Cyanosis absent despite of sufficient reduced
hemoglobin
• In severe anemia, carbon monoxide poisoning

6. Iron replete cyanosis Iron deplete cyanosis
It is compensated erythrocytosis
which establishes
equilibrium with hematocrit
It is decompensated erythrocytosis
which fails to establish equilibrium
with unstable, rising hematocrit
Iron replete cells are deformable Iron deplete cells are less
deformable
Hyperviscosity symptoms are rare Hyperviscosity symptoms are
frequent

7. • Theories of Cyanosis
• Admixture cyanosis
• Secondary to shunts
• Tardive cyanosis
• Due to reversal of shunt (eisenmengerization)
• Hypoxic cyanosis
• Due to type 1 respiratory failure
• Replacement cyanosis
• Due to abnormal hemoglobins
• Distributive cyanosis
• Venous pooling of blood

8. • Hyperoxia Test (Cardiac vs Pulmonary Cyanosis)
• After giving 100% oxygen for 10 minutes, a repeat
arterial blood gas (ABG) is done and if PaO2 is <150mm
Hg then the cause is cardiac and if the PaO2 improves
to >200 mm Hg, the cause is respiratory

9. • Central Cyanosis
• In central cyanosis, the Sao2 is reduced or an abnormal
hemoglobin derivative is present
• Site : Mucous membranes of oral cavity and skin
• Decreased atmospheric pressure—high altitude
• Cyanosis usually becomes manifest in an ascent to an
altitude of 4000 m (13,000 ft)
• Impaired pulmonary function
• Seriously impaired pulmonary function, through perfusion
of unventilated or poorly ventilated areas of the lung or
alveolar hypoventilation, is a common cause of central
cyanosis
• This condition may occur acutely, as in extensive
pneumonia or pulmonary edema, or chronically, with
chronic pulmonary diseases (e.g., emphysema)
• In the latter situation, secondary polycythemia is generally
present and clubbing of the fingers may occur

10. • Anatomic shunts
• Another cause of reduced Sao2 is shunting of systemic
venous blood into the arterial circuit
• Certain forms of congenital heart disease are associated
with cyanosis on this basis
• Pulmonary arteriovenous fistulae may be congenital or
acquired, solitary or multiple, and microscopic or massive
• The severity of cyanosis produced by these fistulae
depends on their size and number
• They occur with some frequency in hereditary hemorrhagic
telangiectasia
• Sao2 reduction and cyanosis may also occur in some
patients with cirrhosis, presumably as a consequence of
pulmonary arteriovenous fistulae or portal vein–pulmonary
vein anastomoses

11. • In patients with cardiac or pulmonary right-to-left shunts,
the presence and severity of cyanosis depend on the
size of the shunt relative to the systemic flow and on the
Hb-O2 saturation of the venous blood.
• With increased extraction of O2 from the blood by the
exercising muscles, the venous blood returning to the
right side of the heart is more unsaturated than at rest,
and shunting of this blood intensifies the cyanosis
• Secondary polycythemia occurs frequently in patients in
this setting and contributes to the cyanosis

12. Methemoglobin Sulfhemoglobin
Common causes Ingested medication (dapsone,
antimalarial agents)
Local anesthetic
Nitrates or nitrites
Ingested medication
(dapsone, phenacetin,
sulfonamides)
Nitrites
Typical
presentation
Cyanosis
Neurologic symptoms from
headache to coma
Respiratory depression
Cyanosis
Color of the blood Chocolate brown Green
Pulse oximetry Inaccurate Inaccurate
Arterial blood gas PaO2 normal
Methemoglobin is detected on
most machines
PaO2 normal
Confirmatory
testing
Blood gas (arterial or venous) Spectrophotometry or
Gas chromatography
Management Methylene blue (MB) or
Ascorbic acid
Supportive (no antidote)
Exchange transfusion in
severe cases
Lack of response to MB

13. Carboxyhemoglobin
Common causes Inhaled CO gas from fires, gas-powered
generators, kerosene heaters
Smoking
Typical presentation Neurologic symptoms from headache to coma
Chest pain from myocardial ischemia
Headache, malaise
Color of the blood Cherry red
Pulse oximetry Inaccurate
Arterial blood gas PaO2 normal
Carboxyhemoglobin is detected on most
machines
Confirmatory testing Co-oximetry using arterial blood (in stable
patients, venous samples are accurate)
Management High-flow or hyperbaric oxygen

15. • Peripheral Cyanosis
• Peripheral cyanosis is due to a slowing of blood flow and
abnormally great extraction of O2 from normally saturated
arterial blood
• It results from vasoconstriction and diminished peripheral blood
flow, such as occurs in cold exposure, shock, congestive
failure, and peripheral vascular disease
• Often in these conditions, the mucous membranes of the oral
cavity, including the sublingual mucosa, may be spared
• Site :
• Nail bed
• Nose tip
• Earlobe
• Outer lips
• Finger tips
• Extremities

16. Peripheral cyanosis

19. APPROACH TO THE PATIENT
• Time of onset of cyanosis :Cyanosis present since
birth or infancy is usually due to congenital heart
disease
• Central and peripheral cyanosis must be differentiated
• The presence or absence of clubbing of the digits should
be ascertained
• Pao2 and Sao2 should be determined
• Spectroscopic examination of the blood should be
performed to look for abnormal types of hemoglobin

21. LAB TESTS
• CBC
• CHEST XRAY
• ECG
• 2DECHO
• ABG
• OXIMETRIC STUDIES
• SPECTROSCOPE
• HB ELECTROPHORESIS

22. TREATMENT OF CYANOSIS
• Treatment of underlying cause
• Symptomatic treatment of cyanosis
• Warming of the affected areas
• Oxygenation