Final answer:
Wall mounted suction units must be capable of restoring negative pressure in the chest cavity to a gauge pressure of -4 to -8 mm Hg to prevent lung collapse and assist in respiration.
Step-by-step explanation:
Wall mounted suction units should be capable of reestablishing negative pressure in the chest cavity to prevent lung collapse and assist in inflating the lungs. These units play a critical role in medical settings, particularly during surgery or in the treatment of trauma victims. The gauge pressure required to achieve this is typically between -4 to -8 mm Hg during the processes of exhalation and inhalation, respectively. Should air enter the chest cavity, it can cause the lungs to detach from the chest wall and collapse, a condition known as a pneumothorax. Therefore, maintaining or restoring the precise negative pressure is essential for patient care and recovery.