Aspiration means taking “alien” particles together with inhaled air. These particles can be liquid or solid foreign objects, poisonous gases, infectious agents. Regardless of their nature, they always produce a response of the lung tissue. In the worst case it leads to respiratory distress syndrome, as its outcome is usually favorable. Short classification of aspiration syndromes according to their cause:
– Mendelson’s syndrome aspiration of gastric contents;
– As a result of drowning;
– Aspiration of a foreign body;
– Aspiration of mineral and animal oils causes exogenous lipoid pneumonia;
– Trachea by taking small portions foreign particles do not reach the lung tissue.
What are the clinical manifestations?
Mendelssohn syndrome occurs while aspirating a large amount of gastric contents. This is facilitated in patients with impaired consciousness or under the influence of sedatives, unable to control their swallowing reflex and have granted Swallowing muscles. This is a prerequisite for the realization of gastro-oesophageal reflux (regurgitation of gastric contents into the esophagus). Immediately after aspiration bronchial tree and lung parenchyma react with violent inflammatory response. As a major contaminating factor in this case is the low pH of the acidic gastric contents, which is normally in the range 1.8-2.2. Numerous studies have demonstrated the development even at higher values of pH – to 5.9. Department of Mendelssohn syndrome include fever, hypoxemia. Auscultatory can feel wet wheezing limited or scattered diffusely in both lung fields. On the pattern was registered local or scattered shadows of the lung tissue. The lesions that occur in the lungs are serious and very often the outcome is unfavorable.
Aspiration syndrome in drowning can occur in two ways depending on whether it is absorbed fluid. In this case developed ARDS (acute respiratory distress syndrome in adults) as essential for its weight here is the amount of liquid absorbed in drowning and whether it is salty or sweet. In one case develops alveolar and in the other interstitial pulmonary edema (swelling). Although rare (in 12% of cases), drowning is “dry”, ie proceeded without aspiration of liquid into the lungs. The reason for this is the reflector laryngospasm and / or arresting the spontaneous respiration. The recovery in these patients is much safer and faster.
Aspiration of solid particles and objects is more common in children or very elderly patients under the influence of sedatives or of dentures. Arises asphyxia (suffocation) due to an obstacle in the course of the respiratory tract and is usually superimposed spasm of the respiratory smooth muscles. In asphyxia food place jams food particle it is most often in the hypopharynx. Typically, these patients are identified by AFSS (inability to speak) and acute onset respiratory failure. In total obstruction of the larynx or trachea immediately should apply nostrum Heimlich. This is done by covering the patient with both hands and forced induction pressure in the diaphragm to provoke reverse airway course of ingested particles. In obstruction of the lower airways of foreign particles their removal is done by using a bronchoscope.
Bacterial pneumonia and pulmonary abscess aspiration bacterial agents. Under normal circumstances the respiratory tract have a biological filter for the prevention of invading microbial agents. These are the macrophages in their wall that are the first line of defense in meeting with bacterial agent. These protective mechanisms are severely impaired in intubated patients on mechanical ventilation because the tube surrounds the bacterial filter and stops mucous clearance. Therefore this patient group are especially susceptible to aspiration of bacterial agents and complications that follow from this.