Effect of using support surface and positions in operating room to interface pressure

Objective: The aim of this study was to investigate the effect of support surface usage and positions on interface pressure in the operating room. Method: This randomized controlled experimental study was conducted between October 2018 and June 2019 in Manisa Celal Bayar University Hafsa Sultan Hospital Operating Room. The study included patients who had planned surgery in supine and prone positions, who were over 18 years of age, who had no pressure sores in the preoperative period, that lasted more than 2 hours and were willing to participate in the study. A total of 72 patients were selected for each group 12 with 95% power and α = 0.05 error. Block randomization method was used to distribute the groups equally. Randomization was performed by using random numbers table obtained from computer program. In the preoperative period, patients who were in accordance with the research criteria were identified, written informed consent was obtained and the Individual Identification Form was completed, and the pressure injury risk was evaluated with the Braden Pressure Injury Risk Assessment Scale. The patients included in the study on the day of surgery were divided into three groups. Patients were assigned to these groups according to the determined randomization table. Gel support surface was used in the first group, viscoelastic foam support surface in the second group, and standard operating table was used in the third group. A "pressure mapping system" measuring mat was placed between the patient and the support surface on the operating table where the patient's surgery would take place. During the operation, the pressure in the patients' body was recorded and the Pressure Injury Risk Assessment Form was filled in the operating theater. The first 24 hours after surgery was evaluated using the Postoperative Pressure Injury Observation Form. In the study, numerical data were summarized with mean, standard deviation, median, minimum, maximum values, and categorical data were summarized with frequency and ratio values using the IBM SPSS Statistics 25.0 package program. The significance level was 0.05 in all analyzes (except interaction, p <0.1). Results: There was no statistically significant difference between the total body mean interface pressure (mmHg) values between the supporting surfaces in the prone position (p = 0.179; p> 0.05). There was a statistically significant difference between the total body mean interface pressure (mmHg) values between the support surfaces in the supine position (p = 0.002; p <0.05), and the mean interface pressure measured on the viscoelastic foam support surface was significantly higher than the gel support surface and the standard operating table (respectively p = 0.033 and p = 0.002; p <0.05,). There was a statistically significant difference (p <0.001) between the whole body maximum interface pressure (mmHg) values between the support surfaces in the prone position (p <0.001), and the highest interface pressure measured on the viscoelastic foam support surface was significantly lower than the gel support surface and the standard operating table (respectively p = 0.044 and p = 0,000; p <0.05). There was a statistically significant difference the highest interface pressure (mmHg) of the whole body between the support surfaces in the supine position (p = 0,015; p <0,05). The highest interface pressure measured on the viscoelastic foam support surface; it was found to be significantly lower than the standard operating table (p = 0.012; p <0.05). Conclusion: In the study, the use of viscoelastic foam support surface in the operating room was found to be more effective than the use of a standard operating table to reduce interface pressure. It was seen that gel support surface was not as effective as viscoelastic foam support surface. Viscoelastic foam support surface is recommended for patients at risk for pressure injury in the operating room. Keywords; operating room, pressure ulcer, support surface, perioperative nursing, operating room nursing