Role of peritoneal lavage in adhesion formation and survival rate in rats: An experimental study

Following laparotomy, almost 95% of patients develop adhesions. To prevent adhesion formation, peritoneal lavage has been investigated and many different lavage solutions have been proposed. In this study, different peritoneal lavage solutions were evaluated, testing their ability to prevent adhesion formation. Three consecutive steps were followed: (1) The lethal dose of Eschericia coli injected in the rat peritoneal cavity was determined, (2) the morbidity and mortality rates of different solutions for peritoneal lavage (i.e., saline, twice-distilled water, antiseptics, and antibiotics solutions) was investigated, and (3) the capability of the different lavage solutions to prevent adhesion formation was tested. Two hundred and ninety-eight rats were employed in this study. After intraperitoneal injection of E. coli, infection (clinical signs and animal vitality), adhesion formation (explorative laparoscopy, peritoneumgraphy and Zühlke scale grading), and animal performance status were investigated. All differences were evaluated by chi-square and analysis of variance (ANOVA) tests. Saline solution showed a low morbidity rate with no deaths. Twice-distilled water was associated with 100% mortality rate, as opposed to 45-75% for antiseptics, and 0-3% mortality for antibiotics. Antibiotics determined higher adhesion formation by Zühlke score as compared to saline solution (p < .001), while no difference was observed between antiseptics and saline (p = NS). Peritoneal lavage with 37°C saline solution was associated with low adhesion formation and high survival rate as compared to twice-distilled water and antiseptics. Antibiotics solutions had high survival rate and high adhesion formation. Twice-distilled water and antisepsis should be avoided when based on the data obtained in this work.