بررسی تاثیر وضعیت نیمه نشسته ومدت زمان آن برروی نتایج گازهای خون شریانی بیماران تحت تهویه مکانیکی بستری در ICU عمومی

Position changing with blood distribution to different portions of lung    can produce V/Q mismatch, and finally extend to oxygenation disruption.    Thus, if position changing  is done’ neglecting the patients’ pulmonary    problem types, not only does it fail to cause oxygenation improvement, but    it also induces gas exchange impairment, and with provocation of     hypoxemia and respiratory acidosis, serious problems  result. The goals of this    research are to determine the semi-fowler’s position and its duration effect    on the arterial blood gases(ABGs)results in patients under mechanical    ventilation hospitalized in general ICU.           In this study , 30 ICU patients(22 males and 8 females) under mechanical    ventilation were chosen. Then using questionnaires , the patients’    demographic data were collected . A sample of arterial blood from these    patients lying in supine position, was taken . Again the patients immediately      were placed in semi-fowler’s position and after 15,30,45,and 60minutes lying    in this position, samples of arterial blood were taken and sent to laboratory.           The findings showed that semi-fowler’s position did not have any positive    effects on oxygenation and gas exchange. Also, the findings indicated that    the effect of lying duration(15,30,45,60 minutes) in semi-fowler’s position on    oxygenation and gas exchange wasn’t significant.           It was concluded that without considering the lung pathology, semi    fowler’s position should not be used , because not only is this position unable    to induce oxygenation-improvement, but actually it may causes gas    exchange impairment.