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ABSTRACT: Introduction & Objective: Positioning is an important part of perioperative care that optimal respiratory function is a main purpose. Thus oxygen saturation measurement in routine surgical positions could be a proper index of respiratory function. Material & Methods: To determine effects of supine , prone and litatomy positions on arterial oxygen saturation , 31 healthy volunteer were positioned in each three position for ten minutes periods . oxygen saturation was measured by pulse oximeter. Results: there was no significant difference between 3 position in oxygen saturation Conclusion: Absent of prone and lithotomy positions effect on oxygenation in this study may be attributed to the short time that the subjects were in each position (ten minutes). we suggest that evaluation of position effect on oxygenation require further investigation

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ABSTRACT Introduction & Objective: Position of patients after open heart surgical operation in ICU in semi sitting and supine position has been propounded as a medical maneuver to improve oxygenation, to prevent hypoxia and its dangerous results since long times ago. No study has been conducted so far to compare the effect of two above mentioned positions on gas exchange rate and improving oxygenation and preventing hypoxia in Iran. Present study was conducted aiming to measuring the arterial blood gases and evaluating the effect of charging position and its duration on the results of arterial blood gases in patients who have been under open heart surgery operations. Materials & Methods: Subjects of this study were 30 patients, aged 18-60 years, which were selected by easy sampling method in ICU of heart surgery center of Mazandaran. The effect of position and its duration from semi sitting position to supine in intervals of 15, 30, and 45 and 60 minutes on arterial blood gases rate (pa O2, pa CO2, sp O2) was measured using analyzer. Necessary information was obtained from each patient’s file and lab results. SPSS software, version 11.5, was used to analyze the data. Results : The average of spO2 (oxygen saturation rate of arterial blood) before changing position (semi sitting) was 98.77±0.180 and after changing position (supine) in intervals 15, 30 and 45 minutes was 98.79 ± 0.163 and in 60 minute it reached 98.43 ± 0.440 but the differences was not significant. The average of pa CO2 (CO2 pressure of arterial blood) before changing position was 37.92 ± 0.765 and after changing position in intervals reached to 38.67 ± 1.03, 37.52 ± 1.03 and 37.95 ± 0.967 and in 60 minute reached to 37.50 ± 0.842 but the differences was not significant. The average of paO2 (oxygen pressure of arterial blood) before changing position reached 145.72 ± 6.11 and 30 minute after changing position reduced to 143.49 ± 5.78 and after 60 minutes it increased to 146.31±6.26 but the differences was not significant. Conclusion: In this study, it was observed that changing the position and duration don’t significantly change the rate of paO2, paCO2, spO2 and arterial blood gases and therefore these patients should not placed in semi sitting position to improve better gaseous exchange. This position doesn’t cause positive effect on exchange of arterial blood gases and it is better that those patients placed in supine position to prevent bedsore, in vulnerable area, and sliding patient over bed.