CausesCauses of peripheral cyanosis include:
Anything that would cause central cyanosis, with resultant bluish coloration in all peripheral tissues.
Hypothermia. The low body temperature constricts the vessels in the skin.
Thromboembolism, or a blood clot
Application of a tourniquet (accidental, deliberate or malicious)
Shock (inadequate blood flow to the tissues)
Causes of central cyanosis would include:
Heart Causes
Congenital heart disease
Tetralogy of Fallot, which is a genetic defect involving four abnormalities of the heart and great vessels
Atrial septal defect (the proverbial "hole in the heart"), with subsequent right-to-left shunting
Ventricular septal defect ("hole in the heart") with subsequent right-to-left shunting
Reversed patent ductus arteriosus (this congenital defect does not initially cause cyanosis. Only if it goes undetected or untreated so that blood flow in the heart reverses, can changes occur that lead to cyanosis)
Lung Causes
Hypoventilation (inability to breathe properly)
Pleural effusion (blood, pus, lymphatic fluid, cancer-induced fluid, etc. that gathers in the chest cavity and prevents the lungs from expanding properly)
Pneumothorax
Respiratory muscle failure
Muscle disorder (like a diaphragmatic hernia)
Neurologic disease
Anesthetic overdose
Airway obstruction
Laryngeal paralysis
Tumor, abscess, granuloma, foreign body obstructing a large airway
Inadequate oxygen due to improperly administered anesthesia
Ventilation-perfusion mismatch (improper blood supply to the lung, combined with improper lung function, or both)
Pulmonary thromboembolism (blood clot in the lungs)
Infiltration of the lung tissue with fluid (edema)
Inflammatory cells (infection, inflammation)
Cancer cells
Acute respiratory distress syndrome (ARDS)
Pulmonary fibrosis (pulmonary scar tissue)
Other Causes
Abnormal hemoglobin (methemoglobin) can result in cyanosis due to chemicals that render the hemoglobin nonfunctional.
Nitrates
Nitrites
Acetaminophen (Tylenol®)
Methylene blue
Cetacaine
Topical benzocaine
