Anesthesiology and Intensive Care

Bowel obstruction: Obstructed bowel is a closed space.  Emphysema: Blebs can accumulate N2O and burst. Air embolism: If suspected, turn off N2O immediately. Eye surgery when intraocular gases are used: Expansion of gas bubble can cause blindness. Middle ear surgery: Accumulation can dislodge a tympanic graft after tympanoplasty. Chest wall or head trauma: N2O can ↑ pneumothorax or ↑ ICP respectively _________________________________________________________________________________ Кишечная непроходимость: ущемленная кишка в закрытом пространстве Эмфизема: буллы могут накапливать N2O и разрываться Воздушная эмболия: при подозрении немедленно остановите подачу N2O  Глазная хирургия при использовании внутриглазных газов: расширение глазного яблока может привести к слепоте Хирургия среднего уха: накопление N2O может оттеснить тимпанический шунт после тимпанопластики Травма грудной стенки или головы: N2O может усугубить пневмоторакс...

During induction of  general anesthesia  when a large volume of  nitrous oxide  is taken up from  alveoli  into pulmonary capillary blood, the concentration of gases remaining in the alveoli is increased. This results in effects known as the " concentration effect " and the "second gas effect". These effects occur because of the contraction of alveolar volume associated with the uptake of the nitrous oxide.      Second gas effect  occurs when the uptake of one gas enhances the rate of rise of alveolar partial pressure of another gas that is administered at the same time. The second gas effect causes an acute increase in the arterial partial pressure of oxygen by 10% when nitrous oxide is initially administered.This is called alveolar hyperoxygenation.