Background. An increased intraluminal pressure in the small intestine due to paralytic intestinal obstruction refers to one of the most important factors for development and severity of intra-abdominal hypertension in patients with diffuse peritonitis. Measurement of intraluminal pressure in the small intestine appears technically challenging, therefore, evidence on the effect of intraluminal pressure on the severity of intra-abdominal hypertension is yet to be gathered. Aim. To evaluate the influence of intraluminal pressure on the severity of intra-abdominal hypertension in patients with diffuse secondary peritonitis.Methods. The research was performed according to the design of an observational clinical study on the basis of Regional Clinical Emergency Hospital, Krasnodar Krai, in the period of July 2022‒April 2024. The study considered dynamics of intra-abdominal pressure in 82 patients with diffuse peritonitis. Intraluminal pressure in the small intestine before and after decompression was measured in 34 patients (Group 1) when nasointestinal intubation was performed with the original tube. Group 2 included 48 patients subjected to measuring intra-abdominal pressure without nasointestinal intubation. The measurement of intra-abdominal pressure was performed through urinary catheterization using the Kron technique according to the recommendations of the World Society of the Abdominal Compartment Syndrome (WSACS). The severity of peritonitis was determined using the World Society of Emergency Surgery complication Intra-Abdominal Infections Score (WSES cIAIs Score). Statistical analysis and comparison of ordinal indices in different groups or subgroups were carried out by means of Mann-Whitney U-test; comparison of quantitative indices with normal distribution was performed using Student’s t-test.Results. All patients in Group 1 were detected with a sharp increase in intraluminal pressure in the small intestine, which appeared 50%-responsible for intra-abdominal hypertension. However, no statistically significant dependence between the severity of peritonitis and severity of intra-abdominal hypertension was revealed due to the variety of factors behind peritonitis development and duration of the disease, which determine the severity of paralytic intestinal obstruction. Nasointestinal intubation in Group 1 patients led to a decrease in intraluminal pressure on the average by 59.4% immediately after decompression, which was accompanied by a decrease in intra-abdominal pressure indices by 49.5% from the initial ones. In group 2, intra-abdominal pressure decreased gradually; during the first 5–7 post-operative days its indices in the majority of patients corresponded to the second degree of intra-abdominal hypertension severity.Conclusion. The level of intraluminal pressure in the small intestine determines the level of intra-abdominal hypertension in patients with diffuse secondary peritonitis. Intraluminal pressure depends on the severity of paralytic intestinal obstruction and the pathology behind peritonitis. The level of intraluminal pressure over 30 mm Hg can be considered critical for the development of severe intra-abdominal hypertension and abdominal compression syndrome. In Group 1, nasointestinal decompression of the small intestine enabled intra-abdominal pressure to be rapidly reduced to acceptable level and development of abdominal compression syndrome to be prevented.
