Abstract
Aim. The purpose of this study was to examine the effect of bed angle on back pain, urinary retention and vascular complications after coronary angiography.
Background. To minimize the severity of low back pain and urine retention after angiography, modalities such as changing position, changing bed angle, and early out of bed have been used, but there is still controversy about the appropriate bed angle that reduces cardiovascular complications and at the same time provides patient comfort.
Method. This study was a randomized clinical trial conducted on 120 patients after angiography in cardiology and angiography wards of Shahid Sadoughi Hospital, Yazd, Iran, in 2018. A total of 120 patients who were candidates for angiography were randomly divided into control and experimental group. After angiography, for the control group, the bed angle was zero, and for the experimental group, the bed angle was set at 30 degrees, from entry to the ward for 4 hours. Data collection tools included demographic and clinical information questionnaire, numerical scale for measuring severity of pain, hematoma and hemorrhage recording form and urinary retention observation and recording form. Data analysis was performed in SPSS Version 20 using descriptive and inferential statistics.

Findings. The mean score of back pain in the experimental group, immediately and four hours after angiography was 0.166±0.767 and 0.216±55.0, respectively, which was lower than that of control group (0.233±0.615 and 0.433±0.927, respectively), but the difference was not statistically significant. Also, there was no statistically significant difference between groups in terms of urinary retention, immediately and 2 hours after angiography. There was no statistically significant difference between groups in terms of vascular complications (hematoma and hemorrhage).

Conclusion. The results of this study did not show any evidence that 30 degrees bed angle adjustment have any different effect on pain severity, urinary retention, and vascular complications of the zero degree bed angle. It is recommended that after angiography, the angle of the bed be set to zero or 30 degrees according to the patient's comfort and preference.