Final answer:
Typically, one chest tube is placed in the pleural space on the side with the pneumothorax to reestablish negative pressure and re-inflate the collapsed lung. Suction is used to withdraw air from the chest cavity.
Step-by-step explanation:
In the case of a unilateral pneumothorax, where air enters the chest cavity, breaking the attachment of the lungs to the chest wall and potentially causing a lung collapse, typically one chest tube is used to reestablish the negative pressure. This tube is often placed in the pleural space, which is the area between the lung and chest wall. The specific placement within this space can vary but is generally inserted on the side of the pneumothorax, either anteriorly, just above the rib to avoid the neurovascular bundle, or laterally, depending on the location of the air leak and the preference of the medical professional. Suction is applied to the tube to withdraw air, reestablishing the negative pressure necessary to re-inflate the lung.