The Effect of Patients Positioning on Oxygen Saturation in the Acute Phase of Ischemic Stroke

Body position is known to influence respiratory function in normal subjects & those with respiratory pathology. Its effect on respiratory function after stroke has received little attention. It's generally thought that stroke morbidity is increased by inappropriate position during early recovery phase. The present study was designed to identify changes in arterial oxygen saturation (SaO2) associated with different four positions of the patient in order to detect proper position which maintain the optimum level of SaO2. Quasiexperiment research design was applied in this study. This study was conducted in stroke intensive care unit of Neurological Department of Assuit University Hospitals. The subjects of this study consist of 60 patients with acute ischemic stroke within 48 hours following mild to moderate and sever stroke. Three tools were included in the study, tool of sociodemographic data, tool of the positions and tool of the Scandinavian stroke scale. The result of the present study revealed that there was statistically significant difference between SaO2 and blood pressure of the patients before and after the positions. It was found also that total mean of SaO2 during right side, supine and semi-setting position was nearly equal and there was statistically significant difference between left position and 3 other positions. So, the study recommended the importance of changing patient's positions which improve ventilation and blood pressure. The importance of the use of positions tested (Rt. side, supine and semi-setting position) in the clinical practice to maintain SaO2 in patients of ischemic stroke.


INTRODUCTION
strokes result from low cerebral blood flow usually because of occlusion of blood vessels.(3)(4) Early recognition & prompt entry into emergency medical system are essential to reduce death & disability from stroke. (2,5)It's generally agreed that hypoxia should be avoided in the acute phase of stroke.Full in oxygenation could affect the vulnerable ischemic brain. (6)Body position is known to influence respiratory function in normal subjects & those with respiratory pathology.Its effect on respiratory function after stroke has received little attention. (6)'s generally thought that stroke morbidity is increased by inappropraite positioning during early recovery phase. (7,8) ntil now, for patients with ischemic stroke no studies to date have evaluated the effect of patients positioning on stroke out come. (9,10)Although there are no data from standardized studies, moderate elevation of the head is standard practice in most institutions. (10)owever

1-To identify changes in arterial
Oxygen saturation (SaO2) associated with different positions of the patients 2-To detect proper position which maintains the optimum level of SaO2.

Design:
Quasiexperimental research design was adopted for this study.Setting: The Tool of the scale: Scandinavian stroke scale tool (11) to assess neurological status of patient with ischemic stroke with total score of (58).

Methods
-Permission to conduct the study was taken from hospital responsible authorities after explanation of the aim of the study.
-Data collection tools were developed based on review of relevant literature. -

RESULTS
A total of 60 patients were enrolled in this study:  It was noticed also that there were statistically significant differences between the right side position and supine position & gait item.    It is generally thought that stroke morbidity is increased by inappropriate position during early recovery phase (7,8) .So the present study tried to identify changes in SaO2 associated with different four positions of the patient in order to detect proper position which maintains the optimum level of SaO2.The present study revealed that mean age of the patient was 54.416 ± 10.722, while more than half of the patients were males.This result may be attributed to that males were more smoker, more stressfull & have more high cholesterol than females.The results of the present study were in line with study done by Schwarz, et al., (10) on the effect of body position on cerebral perfusion in patients with stroke, who stated that mean age of the patients was 61.2 years while more than half of the patients were males.Also study done by stroke information of the patient family (12) who mentioned that 28% of people suffer stroke in given year are under age of 65 years.While Hicks (13) who stated that stroke can affect people of any  (14)(15) .Study done by Schworz, et al., (10)  Yeaw (1992) (16)

Single7%
Stroke is the third leading cause of death & adult disability preceded by heart disease & cancer. (1)According to the National Stroke Association stroke is one of the leading causes of permanently disability in adult.American Heart Association estimated that 15 to 20 billion dollars are spent annually on stroke & stroke related disorders. (2)Stroke is a descriptive term for the onset of acute neurological deficit persisting for more than 24 hours & caused by the interruption of blood flow to the brain.
and changes in SaO2 during time spent in the test positions.The study reported that there were no changes in SaO2 across the hour spent in each position and no differences in SaO2 were identified among positions. (5)It's clear from the researches that few which were directed specifically toward positioning, the patient with ischemic stroke which reflects the need for further research to supplement the present body knowledge.Hence this study was designed to identify changes in SaO2 associated with different position of the patients in order to detect proper positioning which maintains the optimum level of SaO2.
study was carried out in the stroke intensive care unit of Neurological Department of Assuit University Hospital.Subjects: Convenient sample of 60 patients were included in this study.The subjects were eligible for the study if they had first anterior circulation acute ischemic stroke within 48 hours following mild to moderately & sever stroke.: in this tool blood pressure & SaO2 were recorded before & after positions, SaO2 was recorded in this tool each 15 minutes during hour spent in semi-setting, supine, right side & left side position.

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The study tools were revised by 5 experts in the field of nursing & neurology to test content validity & clarity.Necessary modifications were done.-A pilot study was conducted on 5 patients not included in the study to test feasibility of the tool.All patients included in the study were informed about the aim of the study & all of them gave informed consent before engaging in the study if possible.In this study, each patient was put in four positions (semi-setting, supine, right side & left side position) -Before putting the patient in any position, blood pressure & SaO2were measured and recorded in tool number (

Figure ( 1 )
Figure (1) Distribution of the studied sample according to their sociodemographic characteristics.
age.Nine out of ten stroke occur in people over the age of 55 years.Hicks mentions also that men are more often affected by stroke than women.The present study demonstrated that the highest proportions of the patients were illiterate or can read & write.This level of education may be a barrier to complaine with treatment and awareness of the warning signs of the stroke.So a primary public health should focus on increased the awareness of the stroke symptoms particularly among people at high-risk to decrease delay in early detection & effective stroke treatment.The current study revealed that blood pressure & SaO2 of the studied sample after finishing from position were better than blood pressure & SaO2 before starting positions.There were statistical significant differences between blood pressure & SaO2 before & after positions.This result may be attributed to change of mentioned that before any position change of the stroke patient, assess the patient to determine baseline data as respiration, blood pressure, mental status & SaO2 to evaluate the effect of the Bull High Inst Public Health Vol.37 No.4 [2007] position, change by comparing your findings before & after change of position to your base line assessment.It was clear from the results of the present study that the highest mean of SaO2 of the study subject during total hours spent in the position, was in the right side followed by supine position & semi-setting position & it was noticed that differences between means of SaO2 in the three mentioned positions were very little & there was statistically significant difference between left side position & these three mentioned positions.While study done by chalterton, et al., (2000) ( 6) who reported that mean SaO2 values for all patients were > 90 for the hour spent in each test position.For all patients there were no changes in SaO2 across the hour spent in the test position difference in SaO2.Study done by Brainin (17) who tested the safety of positioning the stroke patient on the left side versus right side.Brainin measured oxygen saturation, breathing rate, blood pressure, pulse, & ECG on 18 patients with stroke.There were no significant differences seen in any measurement comparing the two positions.No decrease in SaO2 was found over the course of the test for either positions.Study done by Schworz et al., (2002) (10) on the effect of body position on cerebral perfusion in stroke patients, revealed that cerebral perfusion was highest in the flat position (77.0 ± 1.8 mm/hg) & decreased to 70 .0± 1.8 mm/hg at 15 further to 64.7 ± 1.7 mm/hg at 30 perfusion return to base line value (77.2±1.8 mm/hg) at the end of the protocol.It was noticed from the results that scores of the studied patients as regard Scandinavian scale were very poor in comparison to total score.This may be due to the condition of the patients in early recovery phase was unstable.The neurological scale which was used as standardized measure of neurological function & stroke severity.

Table ( 1
) Distribution of the studied sample according to their socio-demographic characteristics, number = 60 patients

Table ( 5
) Distribution of the study sample according to score of Scandinavian stroke scale .
keenan Nl, Donchoo RS, Malarcher AM, et al.Sex differences in US