The preventive effect of dopamine infusion in rats with abdominal compartment syndrome

Relation between intra-abdominal pressure and early intestinal ischemia in rats

Background

Little is known on early irreversible effects of increased intra-abdominal pressure (IAP). Therefore, timing of abdominal decompression among patients with abdominal compartment syndrome remains challenging. The study objective was to determine the relation between IAP and respiratory parameters, hemodynamic parameters, and early intestinal ischemia.

Methods

Twenty-five anesthetized and ventilated male Sprague-Dawley rats were randomly assigned to five groups exposed to IAPs of 0, 5, 10, 15, or 20 mm Hg for 3 hours. Respiratory parameters, hemodynamic parameters, and serum albumin-cobalt binding (ACB) capacity as measure for systemic ischemia were determined. Intestines were processed for histopathology.

Results

IAP was negatively associated with mean arterial pressure at 90 (Spearman correlation coefficient; Rs=-0.446, p=0.025) and 180 min (Rs=-0.466, p=0.019), oxygen saturation at 90 min (Rs=-0.673, p<0.001) and 180 min (Rs=-0.882, p<0.001), and pH value at 90 (Rs=-0.819, p<0.001) and 180 min (Rs=-0.934, p<0.001). There were no associations between IAP and lactate level or ACB capacity. No histological signs for intestinal ischemia were found.

Discussion

Although increasing IAP was associated with respiratory and hemodynamic difficulties, no signs for intestinal ischemia were found.

Level of evidence

Prognostic and epidemiologic study, level II.

Renal Perfusion and Function during Pneumoperitoneum: A Systematic Review and Meta-Analysis of Animal Studies

Both preclinical and clinical studies indicate that raised intra-abdominal pressure (IAP) associated with pneumoperitoneum during laparoscopic surgical procedures can cause renal damage, the severity of which may be influenced by variables such as pressure level and duration. Several of these variables have been investigated in animal studies, but synthesis of all preclinical data has not been performed. This systematic review summarizes all available pre-clinical evidence on this topic, including an assessment of its quality and risk of bias. We performed meta-analysis to assess which aspects of the pneumoperitoneum determine the severity of its adverse effects. A systematic search in two databases identified 55 studies on the effect of pneumoperitoneum on renal function which met our inclusion criteria. There was high heterogeneity between the studies regarding study design, species, sex, pressure and duration of pneumoperitoneum, and type of gas used. Measures to reduce bias were poorly reported, leading to an unclear risk of bias in the majority of studies. Details on randomisation, blinding and a sample size calculation were not reported in ≥80% of the studies. Meta-analysis showed an overall increase in serum creatinine during pneumoperitoneum, and a decrease in urine output and renal blood flow. Subgroup analysis indicated that for serum creatinine, this effect differed between species. Subgroup analysis of pressure level indicated that urine output decreased as IAP level increased. No differences between types of gas were observed. Data were insufficient to reliably assess whether sex or IAP duration modulate the effect of pneumoperitoneum. Four studies assessing long-term effects indicated that serum creatinine normalized ≥24 hours after desufflation of pneumoperitoneum at 15mmHg. We conclude that harmful effects on renal function and perfusion during pneumoperitoneum appear to be robust, but evidence on long-term effects is very limited. The reliability and clinical relevance of these findings for healthy patients and patients at high risk of renal impairment remain uncertain. We emphasize the need for rigorous reporting of preclinical research methodology, which is of vital importance for clinical translation of preclinical data.