Effect of Intrabronchial Insufflation of Acid

Abstract

Acid administered to rabbits by intrabronchial insufflation causes an immediate and extreme damage of the lung tissue. Within certain limits the degree and extent of the injury vary according to the concentration of the acid. With the greater concentrations death occurs promptly, almost immediately, and the lethal process has associated with it a decreased permeability of the pulmonary vessels. The latter fact has been confirmed by postmortem arterial injections. With weaker solutions the results, grossly and histologically, resemble those noted after influenzal pneumonia and gas poisoning. Thus, there is destruction of the epithelium of the bronchioles, the alveolar ducts, and the alveoli. The extent of the damage to the alveolar walls varies. Exudation occurs into the alveolar, interstitial, perivascular, and peribronchial tissues. Primarily this exudate is serous, but a rapid deposition of fibrin occurs, and later polymorphonuclear leucocytes and erythrocytes accumulate. In different animals, or in different portions of the same lung, there may be consolidations of different types, serofibrinous, hemorrhagic, or purulent, with or without destruction of the alveolar walls. Subsequent changes relate to the organization of the exudate, necrosis, proliferation of the epithelium in the alveoli and bronchi, and, finally, to the regeneration of the pulmonary parenchyma. Experiments now in progress indicate that similar changes can be induced by various acids, both inorganic and organic. Experiments also show that similar changes are produced in other species of animals but that species differ in their resistance according to the acid and the concentration in which it is employed.

On the pulmonary toxicity of oxygen. 5. Electronic structure and the paramagnetic property of oxygen

“…The direct inhalation of hot gas is a form of energy transfer and the pulmonary changes (Wilhelm and Mason, 1960) differ from the secondary lung lesions seen in persons dying from extensive dermal burns (Sochor and Mallory, 1963). Somewhat similar are the lung lesions from inhalation of phosgene partially recreated experimentally by the installation of dilute hydrochloric acid (HCl) (Winternitz, et al, 1920). Since HCl is a monoprotic acid, oxidation per se is not part of its effect on the lung.…”

Airway management in patients undergoing emergency Cesarean section

“…Winternitz and colleagues reported in 1920 the effect of hydrochloric acid infused into the bronchi of rabbits [13], although they were not thinking of aspiration of gastric acid but of war gases liberating free chlorine. Apfelbach and Christianson (in 1937) [14] were probably the first to report pathological changes caused by aspiration of gastric acid through animal research.…”

ABM Clinical Protocol #25: Recommendations for Preprocedural Fasting for the Breastfed Infant: “NPO” Guidelines

“…When this was established, all patients had to be NPO or nothing by mouth after midnight to avoid pulmonary aspiration syndrome. 7,8 The fasting guidelines have developed through the years to be more reasonable for breastfeeding infants 3 and are still evolving. Although potentially uncomfortable for the infant, the safest practice and most effective prevention of pulmonary aspiration is adherence to current fasting guidelines.…”

“…While the incidence of aspiration is low with proper fasting (anywhere from 3 to 10 out of every 10,000 anesthetics performed on children), 3,12 the consequences of pulmonary aspiration of residual gastric contents can be serious. [5][6][7][8]12 Aspiration pneumonitis may necessitate mechanical ventilation and/or a prolonged hospital course. 3 Infants with multiple co-morbidities are placed in a higher risk stratification by the ASA, and they have a higher incidence of aspiration.…”