The dynamics of abnormalities of the biochemical composition of bile under the influence of two-hour tourniquet limb ischemia and acute blood loss in the experiment

Abstract

Introduction. Traumatism is one of the most current problems nowadays. Its increase is caused by the escalation in number of emergencies. In recent years the proliferation of frequency of terrorist attacks and local armed conflicts has been observed. Under those circumstances, the acute blood loss is considered to be the leading cause of injured people’s death. An effective way of stopping a massive external haemorrhage from the limbs is applying the tourniquet which entirely ceases arterial blood flow. It is deemed that safe duration of tourniquet application is two hours. Individual authors’ researches indicate the negative impact of post-tourniquet reperfusion on body. However, influence of the acute blood loss, which is complicated by limb ischemia-reperfusion, on the internal organs is insufficiently studied.           
            Objective of research: to establish peculiarities of the functional state of the liver under impact of two-hour tourniquet limb ischemia and acute blood loss in the experiment.
            Materials of the research and their discussion. The experiments were conducted on 96 non-linear male rats weighing 200-220g. All animals were divided into four groups: control and three experimental ones. Injuries were inflicted under thiopental l- sodium anesthesia. In the first experimental group, the limb ischemia-reperfusion injury was performed on animals by a method of applying a band of an elastic tourniquet SWAT-T. (USA), the width of 10 mm, proximally to the rat’s left paw for 120 minutes. Acute blood loss (20% of circulating blood volume) was performed by severing a femoral vein in the second experimental group.  In the third experimental group, these lesions were combined. The control group included the animals, which were injected into anesthesia and subsequently were used for investigations in an hour.        
            An hour and two hours later, as well as in 1, 7 and 14 days, the functional state of the liver was determined in experimental animals through collecting the bile within an hour with a further determination of the total bile acids concentration, the cholesterol and calculation of the cholate-cholesterol coefficient.

            Result of the research and their discussion. It was established that the two-hour exsanguination of the limb in the reperfusion period can negatively affect the functional state of the liver with a maximum of abnormalities after 3 hours. In comparison with the control group, the content of total bile acids in the bile appreciably decreased and the cholate-cholesterol coefficient increased. Under the circumstances of the acute bleeding, the abnormalities were significantly greater. The reduction in the content of the total bile acids in bile and the cholate-cholesterol ratio was perceived at all periods of the observation as well as the increase in the content of the cholesterol after 1 and 7 days of the experiment, which indicate the dysfunctions in process of the bile acids synthesis from cholesterol and the amplification in lithogenic characteristics of bile. For the first time, it was shown that the combination of acute blood loss and limb ischemia-reperfusion exacerbated the dysfunction of functional state of the liver. Besides, a greater decrease in the content of total bile acids in bile, particularly in 3 hours, in 1 and 14 days of experiment, a significant increase in cholesterol content and a reduction in cholate-cholesterol coefficient after three hours of reperfusion period were observed.           
            Consequently, the two-hour tourniquet application in the condition of the acute blood loss in the amount of 20% of circulating blood volume aggravates the liver dysfunction in comparison to each of the effects in particular. This should be taken into consideration while assisting injured and affected people with acute blood loss from limbs, who were being applied with tourniquet. Our results aim at searching for efficacious tools of counteracting the impact of limb ischemia-reperfusion in conditions of acute blood loss.     
            Conclusions. The complication of acute blood loss by limb ischemia-reperfusion is accompanied by a summation of their negative impact on the functional state of the liver with a maximum value after 3 h - 1 day of the experiment. Under these circumstances, in 3 hours, 1 and 14 days the content of total bile acids in bile is statistically probably lower compared to the experimental group in which the acute blood loss was solely performed. The increase in the content of the cholesterol in bile is observed as well as the reduction in cholesterol ratio that are statistically substantial after 3 hours of the experiment.