Temporal–spatial organ response after blast‐induced experimental blunt abdominal trauma

Abstract

Abdominal trauma (AT) is of major global importance, particularly with the increased potential for civil, terroristic, and military trauma. The injury pattern and systemic consequences of blunt abdominal injuries are highly variable and frequently underestimated or even missed, and the pathomechanisms remain still poorly understood. Therefore, we investigated the temporal-spatial organ and immune response after a standardized blast-induced blunt AT. Anesthetized mice were exposed to a single blast wave centered on the epigastrium. At 2, 6, or 24 h after trauma, abdominal organ damage was assessed macroscopically, microscopically, and biochemically. A higher degree of trauma severity, determined by a reduction of the distance between the epigastrium and blast inductor, was reflected by a reduced survival rate. The hemodynamic monitoring during the first 120 min after AT revealed a decline in the mean arterial pressure within the first 80 min, whereas the heart rate remained quite stable. AT induced a systemic damage and inflammatory response, evidenced by elevated HMGB-1 and IL-6 plasma levels. The macroscopic injury pattern of the abdominal organs (while complex) was consistent, with the following frequency: liver > pancreas > spleen > left kidney > intestine > right kidney > others > lungs and was reflected by microscopic liver and pancreas damages. Plasma levels of organ dysfunction markers increased during the first 6 h after AT and subsequently declined, indicating an early, temporal impairment of the function on a multi-organ level. The established highly reproducible murine blunt AT, with time-and trauma-severity-dependent organ injury patterns, systemic inflammatory response, and impairment of various organ functions, reflects characteristics of human AT. In the future, thisThis is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Intestinal Damage and Immune Response After Experimental Blunt Abdominal Trauma

“…The results from the present AT model revealed clinically meaningful injury patterns, which were in line with already published data in humans, showing that the liver and spleen are most frequently affected, whereas only 27% of AT patients display hollow organ injuries (with the small and large intestines being most affected) (5). Similar to clinical reports, we also found a relatively moderate incidence (36%) of intestinal injuries, whereas liver and spleen were injured more frequently (11). One reason for the only minor intestinal damage could be the overall large surface of the intestine over which the inflicting pressure could be absorbed in an efficient way.…”

“…The extent of the MAP decrease was similar to the drop seen in other animal models with isolated hemorrhagic shock (15). Furthermore, we observed an increased compensatory heart rate and a significant drop in hemoglobin indicating some intra-abdominal hemorrhage after blunt AT (11). Taken together, the detected intestinal damage could be caused either by the traumatic impact itself or by the circulatory shock after AT.…”

“…1345). In this recently established blunt AT model (11), all animal experiments have been performed according to the existing German Animal Welfare Act. Male C57BL/6JRj mice (Janvier Labs, Le Genest-Saint-Isle, France), with a body weight (BW) of 20 to 25 g and housed under a day/night rhythm of 12/12 hours, were randomly assigned to six groups: each group consisted of 3 to 5 (sham) and 4 up to 8 to 10 animals.…”

“…Another three groups of sham animals were subjected to the same basic experimental conditions (analgesia and anesthesia), but lacking the induction of AT, and were harvested after corresponding periods. Whereas, in the recently published analysis, the remote organ functions were addressed (11), in this study, the focus was set on the intestinal damage and immune response. The major part of the blast-wave experiments was performed with a blast cylinder-abdomen distance of 2.1 cm.…”

“…For analgesia during the observation period, rodents received 0.05 mg/kg BW buprenorphine via subcutaneous injection every 6 hours after AT induction until euthanasia. Using the previously described blast-induced abdominal trauma (11), anaesthetised mice were placed in supine position and the cylinder of the blast wave generator was centred on the epigastrium. The AT induction was performed in the three different distances by a single blast wave as described previously for blunt chest trauma (12).…”