Sevoflurane breakdown produces flammable concentrations of hydrogen.

Background: Fires, explosions, and extreme heat production may occur when sevoflurane reacts with desiccated barium hydroxide lime. The identity of the flammable gas has not previously been published, although carbon monoxide, methanol, formaldehyde, and methyl formate have been identified in low quantities.

Methods: The authors reacted sevoflurane with excess desiccated barium hydroxide lime or soda lime at 55 degrees, 100 degrees, 200 degrees, 300 degrees, and 400 degrees C.

The effects of volatile salivary acids and bases on exhaled breath condensate pH.

Rationale: Recent studies have reported acidification of exhaled breath condensate (EBC) in inflammatory lung diseases. This phenomenon, designated "acidopnea," has been attributed to airway inflammation.

Objectives: To determine whether salivary acids and bases can influence EBC pH in chronic obstructive pulmonary disease (COPD).

Barium hydroxide lime turns yellow after desiccation.

Ethyl violet is added to carbon dioxide absorbents and normally serves as an indicator of absorbent exhaustion. During the course of several prior studies of anesthetic breakdown, we noted (but did not publish) that barium hydroxide lime (BL), but not soda lime, turns yellow upon desiccation. We hypothesize that ethyl violet undergoes chemical reaction to produce a yellow colorant in desiccated BL.

Epithelial lining fluid solute concentrations in chronic obstructive lung disease patients and normal subjects.

The exhaled breath condensate (EBC) method represents a new, noninvasive way to detect inflammatory and metabolic markers in the fluid that covers the airways [epithelial lining fluid (ELF)]. However, respiratory droplets represent only a very small and variable fraction of the EBC, most (approximately 99.99%) of which is water vapor.

Utility of exhaled breath condensates in chronic obstructive pulmonary disease: a critical review.

Purpose Of Review: Evaluation of the utility of exhaled breath condensates in chronic obstructive pulmonary disease.

Recent Findings: Exhaled breath condensates have recently been introduced as a simple, noninvasive method of sampling respiratory fluid in inflammatory lung disorders, including chronic obstructive pulmonary disease. Increases in condensate concentrations of at least 12 markers of inflammation have been reported in these disorders.

The promise and perils of exhaled breath condensates.

The exhaled breath condensate (EBC) approach provides a convenient and noninvasive approach for sampling the pulmonary epithelial lining fluid (ELF). Increased EBC concentrations of more than a dozen inflammatory markers and hydrogen ions have been reported in lung diseases associated with inflammation. However, the usefulness of EBC is compromised by uncertainties concerning the sources of the EBC droplets and by the extreme and variable dilution of ELF droplets with condensed water vapor ( approximately 20,000-fold).

A simple method for estimating respiratory solute dilution in exhaled breath condensates.

Exhaled breath condensates have been widely used to detect inflammatory mediators in the fluid that covers airway surfaces of patients with inflammatory lung disorders. This approach is much less invasive than bronchoalveolar lavage, but respiratory droplets are markedly diluted by large and variable amounts of water vapor. We estimated the dilution of respiratory droplets by comparing concentrations of nonvolatile, reference indicators (total nonvolatile cations, urea or conductivity) in 18 normal subjects with normal plasma concentrations by assuming similar concentrations in the respiratory fluid and plasma.

Carbon monoxide production from sevoflurane breakdown: modeling of exposures under clinical conditions.

Unlabelled: Isoflurane, enflurane, sevoflurane, and especially desflurane produce carbon monoxide (CO) during reaction with desiccated absorbents. Of these, sevoflurane is the least studied. We investigated the dependence of CO production from sevoflurane on absorbent temperature, minute ventilation (VE), and fresh gas flow rates.

Dilution of respiratory solutes in exhaled condensates.

Most exhaled water is produced as gaseous water vapor, which can be collected in cooled condensers. The presence of nonvolatile solutes in these condensates suggests that droplets of respiratory fluid (RF) have also been collected. However, calculation of RF solute concentrations from condensates requires estimation of the dilution of RF droplets by water vapor.