Nitrogen washout therapy for pneumothorax1
Three episodes of bilateral spontaneous nontension pneumothoraces in 2 adolescents with malignancies who refused chest tube placement were treated with a high concentration of inspired oxygen (FiO2 approaching 100%) administered via a tight-fitting nonrebreathing oxygen reservoir mask. This technique of nitrogen washout is a useful, noninvasive method for the reduction of noncritical pneumothoraces, which may obviate the necessity for more invasive procedures, although it has no place in the treatment of pneumothorax causing cardiopulmonary compromise. Two physiologic principles are involved. Breathing a high inspired FiO2 causes nitrogen to be washed out of the alveoli, venous blood, body tissues, and body cavities; this is known as “nitrogen washout.” Second, a great decrease in total tissue gas tension while breathing a high inspired FiO2 facilitates absorption of all gas from a closed body space.