Summary

: no significant difference in the decrease of regional cerebral oxygen saturation between beach chair position and semi upright sitting position .with no direct relation between decrease in mean arterial pressure and decrease in cerebral oxygen saturation.

Abstract

Objectives: to compare the changes of cerebral oxygen tension in different positions, beach chair position (BCP) at 60 degrees and semi upright sitting position (SSP) at 90 degrees, during shoulder arthroscopy and the effect on cerebral desaturation events.
Patients and methods: This prospective study included 220 patients, 150 males (68.18%) and 70 female (31.82%). Average age was 46 years (24-68 years). Patients with a history of cerebrovascular stroke, transient ischemic attacks (TIA), uncontrolled systemic diseases e.g. uncontrolled hypertension, diabetes mellitus, major hepatic or renal diseases and cardiac diseases class 3 or 4 of AHA (American Heart Association) classification were excluded from study. Group A was done at 60 degree BCP and Group B at 90 degree SSP. Vital signs; pulse rate, cerebral oxygen saturation (rSO2) and Mean arterial blood pressure (MAP) were measured, before induction of anesthesia (T0), after induction (T1 [baseline]), after positioning (T2), after induction of hypotension (T3) and at one hour after final position (T4).

Results

No significant difference between the two groups as regard MAP or rSO2 in different stages of surgery (p > 0.05).
In both groups there were highly significant changes (p<0.001) in the MAP from T1 to T2 and T2 to T3.
In both groups there were highly significant changes (p<0.001) in the rSO2 from T1 to T2 only.

Conclusion

no significant difference in the decrease of regional cerebral oxygen saturation between beach chair position and semi upright sitting position .with no direct relation between decrease in mean arterial pressure and decrease in cerebral oxygen saturation.