Inspection Inspection should focus on Signs of respiratory difficulty and hypoxemia (eg, restlessness, tachypnea, cyanosis, accessory muscle use) Signs of possible chronic pulmonary disease (eg, clubbing, pedal edema) Chest wall deformities Abnormal breathing patterns (eg, prolonged expiratory time, Cheyne-Stokes respiration, Kussmaul respirations) Jugular venous distention A sign of hypoxemia is cyanosis (bluish discoloration of the lips, face, or nail beds), which requires the presence of at least 5 g / dL of unsaturated hemoglobin and thus signifies low arterial oxygen saturation (< 85%); the absence of cyanosis does not exclude the presence of hypoxemia.