Intra-abdominal Pressure is Influenced by Body Position?

Background: Increased intra-abdominal pressure (IAP) is a complication related to physio pathological changes with high rates of mortality and morbidity. Abdominal surgery is consider one of the risk factors that can increased IAP. Measurement can be done by direct or indirect methods, being the most used the transurethral (TM). However this method continues to generate some controversy. This study tries to clarify the doubts of the effect of body position when we use different methods to measure IAP. Methodology: Study realized an anatomical model in order to eliminate the described variables that influence IAP: abdominal and gastric contraction, micturition reflex and breathing. IAP was measured, directly, via microsensor and, indirectly, by TM and intragastric manometry, in five different body positions. The study population consists in a population of 29 anatomical model, 14 males and 15 females, with an average weight of 12.04 ± 5.67 kilograms (Kg). The inclusion criteria consisted in the absence of abdominal disease that would. Principal Findings: IAP determination by direct method showed no differences in the five body positions (P=0.765). The indirect method with better correlation with the direct was TM (cc0.87). Indirect methods revealed statistically significant differences with the direct, only in the Trendelenburg and reverse Trendelenburg. Conclusions: The clinical impact of this study is to decrease the doubts in the measurements of IAP. This study improves the knowledge of the application of the direct and indirect methods to accesses IAP. IAP is not affected by body position and the direct pressure value measured in all positions is constant. Only if the indirect methods are used, in Trendelenburg and reverse Trendelenburg positions, they may underestimate or overestimate IAP value. For the first time it was explained why this phenomenon occurs.