Cartridge-operated extinguishers are used for some regular and multipurpose dry chemical and most dry powder Class D extinguishers.

Which of these statements is false?

A) Microbial aerosols are pathogens present in blood that cause disease in humans. B) Asepsis means "freedom from infection." C) An antiseptic is an agent used on living tissue to kill or reduce numbers of bacteria. D) Contamination is soiling by contact or mixing.

A patient breathing room air at sea level has the following arterial blood gases: PaO2 = 62 mm Hg; PCO2 = 75 mm Hg. When the FIO2 is raised to 0.28, the PaO2 rises to 95 mm Hg. What is the most likely cause of the hypoxemia?

a. Hypoventilation b. Impaired diffusion c. Right-to-left shunt d. V/Q imbalance