Negative pressure pulmonary edema is associated with a large inpiratory force that may have been caused due to an obstruction in the wind pipe. The condition of negative pressure pulmonary edema can be observed in patients who are having a laryngeal tumor. Negative pressure pulmonary edema may lead to potentially dangerous condition and is associated with acts of strangulation, sleep apnea.
There are various accidents involving intubation where the patient is biting done on the endotracheal tube. According to reports it has been found that when healthy infants were given muscle relaxants it lead to NPPE at the starting point of inhalation induction of anesthesia. In children it has been found that there is incidence of negative pressure pulmonary edema when the patient has croup and epiglottis leading to upper airway obstruction.
Paralysis can also cause upper airway obstruction. It has been observed that when there is paralysis of the glossal muscles, it may lead to diaphragmatic paralysis which causes the obstruction leads to NPPE. In case of airway obstructions like epiglottis or a laryngospasm there is generation of NPPE and this has been classified as Type 1 NPPE, while type 2 may be caused due to a chronic obstruction like a tumor.