Final answer:
Suction is applied to reestablish negative pressure in the chest cavity to inflate the lungs, with suctioning lasting no longer than 10-15 seconds for adults and around 5 seconds for infants and children, performed only when clinically needed by trained professionals.
Step-by-step explanation:
Applying suction is a critical medical procedure to maintain open airways in patients who are unable to clear their own secretions due to various reasons such as surgery, trauma, or obstruction. The gauge pressure in the liquid adhering the lungs to the inside of the chest wall being negative is essential for proper lung function. For adults and children who undergo surgery or suffer trauma, suction is applied to reestablish negative pressure and inflate the lungs when necessary. Suctioning duration should be brief, generally no longer than 10-15 seconds for an adult, to reduce the risk of hypoxia and other complications. Due to the smaller size of their airways, an infant or child requires even shorter suctioning times, typically around 5 seconds, and always with an appropriate-sized catheter. For infants experiencing choking, turning them upside down and delivering back slaps may dislodge the object; whereas, older children and adults may initially be encouraged to cough and, if unsuccessful, may require the Heimlich maneuver.
It is important to note that suctioning is a procedure that should only be performed when clinically indicated and by trained healthcare professionals to ensure patient safety and efficacy of the procedure.