Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Critical Care giúp cho các bạn có thêm kiến thức về ngành y học đề tài: Extrapulmonary effects of nitric oxide inhalation therapy: time to consider new dosing regimes? | Available online http content 12 1 406 Letter Extrapulmonary effects of nitric oxide inhalation therapy time to consider new dosing regimes Jon O Lundberg1 and Eddie Weitzberg2 1 Department of Physiology and Pharmacology Karolinska Institutet Stockholm Sweden 2Department of Physiology and Pharmacology Section of Anaesthesiology and Intensive Care Karolinska Institutet Stockholm Sweden Corresponding author Jon Lundberg Published 11 February 2008 This article is online at http content 12 1 406 2008 BioMed Central Ltd Critical Care 2008 12 406 doi cc6775 Studies with nitric oxide NO inhalation suggest transformation of NO in the lung into a more long-lived bioactive NO species that also has distal effects 1 2 . The exact nature of these species has not been pinpointed but probable candidates include circulating nitrite anions and or S-nitrosothiols 3 . When using inhaled NO therapeutically for pulmonary disorders the dose is typically expressed as the concentration of NO without adjustments for body size. When inhaling 10 ppm NO the concentration of NO that reaches the lungs with every breath is the same whether it in a mouse a premature infant or an adult. The minute ventilation in relation to body weight however is about three to four times higher in a premature infant compared with an adult so the resulting accumulation of bioactive NO metabolites in blood is much greater. This greater accumulation suggests that the dose of inhaled NO should be adjusted in relation to body weight and also calls for some caution when extrapolating results from animal data to humans. A concentration of inhaled NO that is effective in a small animal may therefore not be sufficient in humans. Conversely a concentration that is effective and safe in adults may cause unwanted toxic effects in premature infants. Several factors will affect the metabolism of inhaled NO into bioactive circulating NO species. The vast majority of inhaled NO
