Type 4 respiratory failure is due to?: (A) ARDS, (B) Shock, (C) Pneumonia, (D) Perioperative atelectasis
Answer is B. Type 4 respiratory failure results from hypoperfusion of respiratory muscles in patients in shock.Normally,respiratory muscles consume<5% of the total cardiac output and O2 delivery.Patients in shock often experience respiratory distress due to pulmonary edema(eg.,patients in cardiogenic shock),lactic acidosis,and anemia. Ref:Harrison's medicine -18th edition,page no:2200.