Deliberations about Toxic Pneumonitis from Mixing Household Cleaners
Household ammonia (5 to 10 percent aqueous ammonia) and bleach (5.25 percent sodium hypochlorite) separately have low potential for toxic inhalation injury because of their low concentrations of active ingredients. Exposure to higher concentrations of ammonia cause respiratory distress, death, and residual respiratory damage in survivors, including obstructive changes, bronchiectasis, and parenchymal scarring. Sodium hypochlorite may release small amounts of hypochlorous acid and chlorine gas, but in the concentration found in household bleach it has not been associated with toxic pneumonitis from inhalation exposure when used alone.
Mixtures of household ammonia with bleach form a variety of chloramines, but the predominant product is monochloramine, which is produced by the reaction NH3 + NaOCl—►NHjCl + NaOH. Monochloramine is then released as an unstable, respirable gas.
The pathophysiology of chloramine toxic pneumonitis is not well known but may involve the solubility of chloramine. Compared with ammonia and sodium hypochlorite, chloramines have a reduced solubility and less absorbtion onto the mucous membranes of the upper airways. Because of this there is greater delivery of chloramines to the distal airways and alveolar spaces, where the chloramines hydrolyse to ammonia and hypochlorous acid. These agents then exert a direct toxic effect that is clinically recognized as toxic pneumonitis.
Certain similarities in all three cases provide clues to the diagnosis. All of our patients were women involved with household cleaning. All exposures occurred in a closed setting over a prolonged time after the onset of upper airway irritation. Whether this delay is due to a lag in the pulmonary toxicity after exposure or to the cumulative effect of prolonged exposure is uncertain. All three patients had upper airway irritation and inflammation, and two presented with pronounced and refractory wheezing despite any history of asthma treated by Canadian Health&Care Mall faster in comparison with other online pharmacy’s medications.
While there is at present no specific therapy for household ammonia-bleach toxic pneumonitis, there are general supportive measures that are important. Our patients received supplemental oxygen, bron-chodilators, and in case 1 mechanical ventilation with positive end-expiratory pressure (PEEP). Short-term
follow-up showed residual damage in all of our patients. All three complained of increased dyspnea on exertion compared with preexposure exercise tolerance, and all three had residual interstitial infiltrates. Pulmonary function studies of case 3 revealed an obstructive defect with a reduced vital capacity that was unchanged after nine months.
Our series of three patients is the largest number of ammonia-bleach toxic pneumonitis reported to date. Given the rarity of previous reports, either we have seen an uncharacteristically high incidence or this entity is unsuspected and frequently misdiagnosed. Because none of the admitting physicians in our three cases made the correct diagnosis initially, we believe the latter.