Postoperative hyponatremia occurred within 24 hours of induction of anesthesia when only near-isotonic fluids were infused. Hyponatremia was generally caused by generation of electrolyte-free water during excretion of hypertonic urine-a desalination process. This electrolyte-free water was retained in the body because of the actions of antidiuretic hormone. If the pathophysiology of this hyponatremic state is understood, recommendations for its prevention and treatment can be deduced.

No abstract

The more labored and asynchronous breathing seen with bubble NCPAP may lead to higher failure rates over the long term than with VF-NCPAP.

E lectronic cigarettes (e-cigarettes) are the most commonly used nicotine products among Canadian youth; a 2017 study estimated that 272 000 Canadians aged 15 to 24 years had used e-cigarettes in the last 30 days. 1 First available in China in 2004 and in the United States in 2006, 2 e-cigarettes are battery-powered devices that aerosolize various substances for inhalation, including nicotine, tetrahydrocannabinol (THC), cannabidiol and flavouring agents that may contain diacetyl, a compound known to cause pulmonary toxicity. 3 Since its introduction to the North American market, use of e-cigarettes, or "vaping," has continued to rise. 4 Although use of this heavily marketed device is rapidly growing and becoming commonplace in Canada-particularly among youth-the impact of e-cigarettes on health is poorly understood. In recent years, several patterns of adverse reactions to vaping have been reported, including hypersensitivity pneumonitis, 5-8 diffuse alveolar hemorrhage, 9 organizing pneumonia, 10-14 acute eosinophilic pneumonia 15,16 and lipoid pneumonia. 17-21 Most recently, a cluster of 53 cases in the US was described as having hypoxemia and bilateral ground-glass opacities, consistent with a diffuse alveolar damage pattern of lung injury. 22 As of Nov.

Nasal continuous-positive-airway-pressure (NCPAP) is popular for infant respiratory support. We compared delivered to intended intra-prong, proximal-airway, and distal-airway pressures using ventilator (V-NCPAP) and bubble (B-NCPAP) devices. Measurements were repeated at five flows (4,6,8,10, and 12 L/min) and three NCPAP (4, 6, and 8 cm H 2 O) under no, small, and large nares-prong interface leak conditions. With no-leak, delivered B-NCPAP was systematically greater than intended levels at all pressure sites. The corresponding V-NCPAP flow-dependence was noneto-minimal. Prong and intra-airway B-NCPAP overshoots were also observed with small-leak, while only prong B-NCPAP showed a flow-dependent overshoot for large-leak. Leaks did not affect intraprong V-NCPAP but resulted in progressively lower than desired, flow-independent intra-airway V-NCPAP. We conclude that the selfadjusting capability of ventilators allows closely matched actual versus intended V-NCPAP. Alternatively, for the range of flows used clinically, intra-prong and intra-airway B-NCPAP are systematically higher at increasing flows than operator-intended levels, even when appreciable nares-prong leak is present. Additionally, the oscillations (noise) characterizing B-NCPAP are substantially attenuated between the proximal and distal airways; therefore, it is unlikely that B-NCPAP engenders ventilation or lung recruitment via this phenomenon. Tubing submersion depth for setting the level of B-NCPAP is highly inaccurate, and operators should instead rely on intra-prong pressure measurement. (Pediatr Res 62: [343][344][345][346][347] 2007) N CPAP is an increasingly popular mode of respiratory support in preterm infants with varying pulmonary disorders. The renewed interest in this form of ventilatory support aims at preventing collapse of the alveoli and terminal airways during expiration while relying on the infant's spontaneous respiration, and thereby avoids both the risk of tracheal intubation and concerns about ventilator-induced lung injury (1,2).A variety of devices are currently used for NCPAP delivery in infants. Most commonly, an infant ventilator is used to generate positive pressure. Flow is continuous and NCPAP pressure can be changed as desired by using the ventilator's positive end-expiratory pressure control. Ventilators maintain the delivered NCPAP pressure (V-NCPAP) close to the set pressure by automatic adjustments at the expiratory valve. Another device, B-NCPAP, has become a focus of interest as it is relatively inexpensive, easy to use, and favored by an institution reporting a low incidence of chronic lung disease (3). Warmed, humidified gas flows to the infant via the NCPAP circuit, binasal prongs are used, and the expiratory limb of the NCPAP tubing is submerged underwater to a depth in centimeters equal to the desired NCPAP. Flow rate is adjusted until gas bubbles through the water chamber. A hypothesized benefit to gas exchange and lung recruitment during B-NCPAP, the high-frequency oscillatory content of the b...

No abstract

A very promising method for the conversion and storage of solar energy into a fuel is the dissociation of water to oxygen and hydrogen, carried out via a two-step process using metal oxide redox systems such as mixed iron oxides, coated upon multi-channeled honeycomb ceramic supports capable of absorbing solar irradiation, in a configuration similar to that encountered in automobile exhaust catalytic converters. With this configuration, the whole process can be carried out in a single solar energy converter, the process temperature can be significantly lowered compared to other thermo-chemical cycles and the re-combination of oxygen and hydrogen is prevented by fixing the oxygen in the metal oxide. For the realization of the integrated concept, research work proceeded in three parallel directions: synthesis of active redox systems, manufacture of ceramic honeycomb supports and manufacture, testing and optimization of operating conditions of a thermochemical solar receiver-reactor. The receiver-reactor has been developed and installed in the solar furnace in Cologne, Germany. It was proven that solar hydrogen production is feasible by this process demonstrating that multi cycling of the process was possible in principle.

A promising method for the conversion and storage of solar energy into hydrogen is the dissociation of water into oxygen and hydrogen, carried out via a two-step process using metal oxide redox systems such as mixed iron oxides, coated upon multi-channeled honeycomb ceramic supports capable of absorbing solar irradiation, in a configuration similar to that encountered in automobile exhaust catalytic converters. With this configuration, the whole process can be carried out in a single solar energy converter, the process temperature can be significantly lowered compared to other thermo-chemical cycles and the recombination of oxygen and hydrogen is prevented by fixing the oxygen in the metal oxide. For the realization of the integrated concept, research work proceeded in three parallel directions: synthesis of active redox systems, manufacture of ceramic honeycomb supports and manufacture, testing and optimization of operating conditions of a thermochemical solar receiver-reactor. The receiver-reactor has been developed and installed in the solar furnace in Cologne, Germany. It was proven that solar hydrogen production is feasible by this process demonstrating that multicycling of the process was possible in principle.