Peripheral cyanosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Eiman Ghaffarpasand, M.D. [2]

Abbreviations: ABG= Arterial blood gas, ANP= Atrial natriuretic peptide, BNP= Brain natriuretic peptide, CBC= Complete blood count, COPD= Chronic obstructive pulmonary disease, CRP= C-reactive protein, CT= Computed tomography, CXR= Chest X-ray, DVT= Deep vein thrombosis, ESR= Erythrocyte sedimentation rate, HRCT= High Resolution CT, IgE= Immunoglobulin E, LDH= Lactate dehydrogenase, PCWP= Pulmonary capillary wedge pressure.

Diseases			Cyanosis		Clinical manifestations						Para-clinical findings							Gold standard	Additional findings
					Symptoms			Physical examination
											Lab Findings				Imaging
			Peripheral	Central	Dyspnea	Fever	Chest pain	Clubbing	Peripheral edema	Auscultation	CBC	ABG	Electrolytes	Other	X-ray	CT scan	Other
Pulmonary diseases	Airway disorder	Severe croup	+	-	+	+/-	-	-	-	Stridor	Lymphocytosis	Normal	Normal	-	Steeple sign	Normal	Distended hypopharynx during inspiration	Clinical findings	Intercostal and subcostal retraction, Barking cough
		Epiglottitis	+	-	+	+	-	-	-	Stridor	Leukocytosis with neutrophilia	Normal	Normal	-	Thumb sign	Normal	-	Laryngoscopy	Muffled voice, Drooling
		Foreign body aspiration	+	-	+	-	+/-	-	-	Decreased breath sounds, Wheezing	Normal	Normal	Normal	-	Hyperinflation, Atelectasis, Objects	Foreign body entrapment with edema or granulation tissue	-	Bronchoscopy	Mediastinitis
		Bacterial tracheitis	+	-	+	+	+	-	-	Inspiratory stridor	Leukocytosis	Normal	Normal	Blood culture, Gram stain	Irregular tracheal margin	Normal	Steeple sign (confusing)	Laryngotracheobronchoscopy	Brassy cough, Hoarseness
	Parenchymal disorder	Alveolitis	+/-	+	+	+	+	+/-	-	Wheeze, Crackles	Leukocytosis, Eosinophilia	↓O2, ↑CO2	Normal	↑ESR, ↑CRP	Scattered opacities, Fine reticulation	Homogeneous ground-glass opacity	-	HRCT PLUS Clinical findings	Malaise, Chills, Headache
		Cystic fibrosis	+	-	+	+/-	+/-	+	-	Wheeze, Crackles	Normal	↓O2, ↑CO2	Increased sweat chloride	Sweat chloride test	Hyperinflation, Nodules	Peribronchial thickening, Bronchiectasis	-	Sweat chloride test	Absent vas deferens
		COPD (Severe emphysema)	+	-	+	+/-	+	+/-	+/-	Reduced breath sounds, Wheeze, Inspiratory crackles	Polycythemia	↓O2, ↑CO2	Normal	Alpha 1-antitrypsin test	Elongated heart, Flattened diaphragms, Prominent hilar vasculature	Bullae	-	HRCT	Pulmonary hypertension, Right heart failure
	Pulmonary vascular disorders	Massive pulmonary embolism	+	-	+	+/-	+	-	+/-	Reduced breath sounds, Crackles, Loud P2	Leukocytosis	↓O2, ↑CO2, Respiratory acidosis	Normal	D-dimer, BNP	Fleischner sign, Hampton hump, Westermark sign, Pleural effusion	Filling defects in the pulmonary vasculature	Spiral CT pulmonary angiogram	Spiral CT pulmonary angiogram	Tachycardia, Shock, Pulmonary hypertension
Chest wall disorders		Flail chest	+	-	+	-	+	-	-	Normal	Normal	↓O2, ↑CO2	Normal	-	≥3 adjacent ribs with segmental fractures, >5 adjacent rib fractures	Normal	-	CXR	Bruises over chest
		Pneumothorax	+	-	+	-	+	-	-	Diminished breath sounds	Normal	↓O2, ↑CO2	Normal	-	No lung marking on one side, Collapsed lung	Loculated air in thoracic cavity	M-mode ultrasonography	Chest CT scan	Tachypnea
Disease			Peripheral	Central	Dyspnea	Fever	Chest pain	Clubbing	Peripheral edema	Auscultation	CBC	ABG	Electrolytes	Other	X-ray	CT scan	Other	Gold standard	Additional findings
Cardiac diseases	Congenital disorders	Atrioventricular canal defect	+/-	+	+	-	+/-	+/-	-	Wheezing,Holosystolic or systolic ejection murmur	Normal	Normal	Normal	Pulse oximetry	Cardiomegaly, Increased pulmonary vascular markings	Normal	Echocardiography, MRI	Echocardiography	Tachypnea, Lack of appetite, Pale skin color, Excessive sweating
	Acquired disorders	Heart failure	+	-	+	+/-	+	-	+	Coarse crackles, S3	Anemia	↓O2, ↑CO2	Hyponatremia, Hypokalemia, Hypomagnesemia	Elevated BNP	Pleural effusion, Cardiomegaly Kerley B lines	Normal	Radioisotope scan	Echocardiography	Generalized edema, Hepatomegaly
		Valvular heart disease	+	-	+	-	-	-	+	Murmurs	Schistocyte	Normal	Normal	Hyperthyroidism	Valve calcification	Normal	Valvular dysfunction in echocardiography	Echocardiography	Syncope, Palpitation
		Cardiogenic shock	+/-	+	+	-	-	-	+	Muffled heart sound	Anemia	↓O2, ↑CO2	Hyperkalemia	↓PaO2 in pulse oximetry	Normal	Normal	Echocardiography	Clinical findings	Tachypnea, Palpitation, Hypotension, Weak pulse
Vascular disease	Arterial disorders	Acrocyanosis	+	-	+/-	-	-	+	-	Normal	Anemia, Leukocytosis	↓O2, ↑CO2	Hypercalcemia	↓PaO2 in pulse oximetry	Normal	Normal	-	Clinical findings	Brittle nails, Telangiectasia
		Arterial embolism	+	-	+	-	+	+/-	-	Normal	Normal	Normal	Hyperkalemia	↓PaO2 in pulse oximetry	Normal	Normal	Transesophageal echocardiography (TEE)	Clinical findings	Headache, Decreased sensation
		Raynaud's Phenomenon	+	-	-	-	-	+	-	Normal	Polycythemia	↓O2	Normal	Mild ↓PaO2 in pulse oximetry	Normal	Normal	-	Clinical findings	Sensitivity to cold, Decreased sensation
	Venous disorders	Superior vena cava obstruction	+	-	+/-	-	+/-	+/-	+	Normal	Polycythemia	↓O2	Normal	↓PaO2 in pulse oximetry	Superior mediastinal widening, Right hilar prominence	Thrombosis, Mediastinal mass or lymphadenopathy, Associated lung mass	-	Chest CT scan	Headache, Facial swelling
		Venous stasis	+	-	-	-	-	+/-	+	Normal	Polycythemia	↓O2	Hypercalcemia	Normal	Normal	Normal	Color-flow duplex ultrasound	Color-flow duplex ultrasound	Leg swelling, Pain during walking, Leg ulcers
Hematologic diseases		Polycythemia	+	+	+	+/-	+/-	+	-	Normal	↑RBC, ↑WBC, ↑HGB, ↑Plt	↓O2	Hyperkalemia	↑Leukocyte alkaline phosphatase, ↑Ferritin, ↑Erythropoietin	AVM, COPD, pulmonary hypertension	Normal	Abdominal ultrasound or renal vascular studies for ruling out renal artery stenosis	RBC mass (RCM) and plasma volume measurement	Itchiness, Headache. Dizziness. Blurred vision
Miscellaneous		High altitude exposure	+/-	+	+	-	+/-	+	-	Wheezing	Polycythemia	↓O2, ↓CO2, Respiratory alkalosis	Hyperphosphatemia, Hypercalcemia, Hyponatremia, Hypokalemia, Hypomagnesemia	Decreased bicarbonate	Central interstitial edema	Pulmonary consolidation	-	Hypoxic challenge test	Dizziness, Coma, Death
		Septic shock	+	-	+	+	+/-	-	-	Rales, crackles, Wheeze, Pleural friction rub	Leukocytosis with neutrophilia	↓O2, ↑CO2, Metabolic acidosis	Hyperkalemia	↑ESR, ↑CRP	Consolidation	Pulmonary infiltration	Echocardiography	Blood culture	Chills, Hypothermia, Loss of consciousness
		Smoke inhalation	+/-	+	+	-	+	-	-	Wheezing	Anemia, Carboxyhemoglobin	↓O2, ↑CO2, Respiratory acidosis	Normal	CO-oximetry	Diffuse opacities	Pulmonary infiltration	Pulmonary function testing	Bronchoscopy	Cough, Hoarseness, Hemoptysis, Headache, Fainting
		Cold exposure	+	-	+/-	-	-	-	-	Normal	Leukopenia, ↑RBC	↓O2, ↑CO2, Metabolic acidosis	Hypokalemia, Hypocalcemia	Hyperglycemia, ↑CK	Normal	Normal	-	Clinical findings	Confusion, Tachycardia/Bradycardia, Coma