The effect of aprotinin in a model of uncontrolled hemorrhagic shock

Establishment and development of a CZE-UV method for rapid measurement of aprotinin potency

A new method for the measurement of aprotinin potency by CZE-UV detector was established for the first time. The on-line mixing of substrate, trypsin and aprotinin using at-inlet technology was realized by the established method. Enzymatic reaction, separation, and detection of substrate and product can be performed simultaneously online. The aprotinin potency can be measured within 4 min. The response surface methodology was used to optimize the incubation conditions of trypsin and substrate, and the optimized conditions were obtained under 17.39 mM phosphate buffer at pH 7.6, 1.40 min of incubation time. The repeatability of proposed method was evaluated in three different systems of capillary zone electrophoresis: (i) only substrate; (ii) trypsin and substrate; (iii) aprotinin, trypsin and substrate, and the RSDs of migration times and peak areas of substrate were less than 2.7 and 3.1%, respectively. The RSDs of migration times and peak areas of product were less than 2.1 and 3.0%, respectively. A formula was also developed to calculate the aprotinin potency in this method. In a word, the established CZE-UV method was convenient, fast, and environmentally friendly for the measurement of aprotinin potency.

Hyperpressure intraperitoneal fluid administration for control of bleeding after liver injury

BACKGROUND

Acute hemorrhage is the principal cause of death in trauma patients, with most fatalities occurring during the pre-hospital phase. Recently, intra-abdominal insufflation by carbon dioxide has been shown to drastically reduce bleeding in vascular and splanchnic hemorrhagic animal models simulating the pre-hospital phase. Here, we propose that using dialysate fluid for increasing intra-abdominal pressure is at least as effective as gas with some potential advantages.

MATERIALS AND METHODS

A novel method of inducing liver trauma was used in 24 White New Zealand rabbits randomized into three groups: intra-abdominal carbon dioxide insufflation (GAS) with 15 cm H(2)O pressure; intra-abdominal infusion of type III dialysate solution (DIAL) with the same pressure; no change in intra-abdominal pressure (CTRL). All groups received intravenous resuscitation when their mean arterial pressure was below 30 mmHg. Physiologic parameters were recorded during 20 min of bleeding.

RESULTS

Red blood cell (RBC) volume loss in the DIAL and GAS was 45% and 48% lower than that in the CTRL, respectively (P < 0.0005). Similar trends were observed for losses in RBC count and hemoglobin (Hb). Final mean arterial pressure, arterial RBC, Hb, and hematocrit were higher in the DIAL and GAS than in the CTRL; glucose concentration in the DIAL group was significantly higher than that in the GAS and CTRL groups. No intravenous fluid therapy was needed in the DIAL group.

CONCLUSIONS

Hyperpressure intraperitoneal dialysate administration successfully reduced bleeding after severe liver injury in rabbits. This method can potentially be used as an adjunct to increase patient survival during pre-hospital cares.

Review of current blood transfusions strategies in a mature level I trauma center: were we wrong for the last 60 years?

BACKGROUND

Recent military experience reported casualties who receive > 10 units of packed red blood cells (PRBC) in 24 hours have 20% versus 65% mortality when the fresh-frozen plasma (FFP) to PRBC ratio was 1:1 versus 1:4, respectively. We hypothesize a similar improvement in mortality in civilian trauma patients that require massive transfusion and are treated with a FFP to PRBC ratio closer to 1:1.

METHODS

Four-year retrospective study of all trauma patients who underwent emergency surgery in an urban Level I Trauma Center. Patients were divided into two groups; those that received < or = 10 units or > 10 units of PRBC during and after initial surgical intervention. Only patients who received transfusion of both FFP and PRBC were included in the analysis. The primary research question was the impact of initial FFP:PRBC ratio on mortality. Other variables for analysis included patient age, gender, mechanism, and Injury Severity Scale score. Both univariate and multivariate analysis were used to assess the relationship between outcome and predictors.

RESULTS

A total of 2,746 patients underwent surgical intervention of which 1,985 (72.2%) received no transfusion. Of those that received transfusion, 626 (22.8%) received < or = 10 units of PRBC and 135 (4.9%) > 10 units of PRBC. Out of the 626 patients that received < or = 10 units of PRBC, 250 (39.9%) received FFP and 376 (60.1%) received no FFP. All the patients that received > 10 units PRBC received FFP. In univariate analysis, a significant difference in mortality was found in patients who received > 10 units of PRBC (26% vs. 87.5%) when FFP:PRBC ratio was 1:1 versus 1:4 (p = 0.0001). Multivariate analysis in the group of patients that received > 10 units of PRBC showed a FFP:PRBC ratio of 1:4 was consistent with increased risk of mortality (relative risk, 18.88; 95% CI, 6.32-56.36; p = 0.001), when compared with a ratio of 1:1. Patients who received < or = 10 units of PRBC had a trend toward increased mortality (21.2% vs.11.8%) when the FFP:PRBC ratio was 1:4 versus 1:1 (p: 0.06).

CONCLUSION

An FFP to PRBC ratio close to 1:1 confers a survival advantage in patients requiring massive transfusion.

The protective effect of aprotinin and alpha-tocopherol on ischemia-reperfusion injury of the rat liver

BACKGROUND

Liver injury caused by ischemia-reperfusion (I/R) processes is a complication of hepatic resection surgery and transplantation, particularly using grafts from marginal donors. Despite improvements in organ preservation and advances in surgical techniques, I/R injury remains a significant clinical problem. In this study, we investigated whether aprotinin provided protection against the adverse effects of I/R injury in liver tissue.

METHODS

Forty rats were randomized into four groups (n = 10): group I: (control group) I/R + no medication; group II: sham-operated group + no medication or I/R; group III: I/R + aprotinin; group IV: I/R + alpha-tocopherol. Malondialdehyde (MDA) was measured in the liver tissue and superoxide dismutase (SOD), catalase (CAT), aspartate aminotransferase (AST), alanine aminotransferase (ALT), as well as lactate dehydrogenase (LDH) in rat serum.

RESULTS

Administration of aprotinin and alpha-tocopherol before I/R resulted in significant reductions of MDA levels compared to the I/R alone group (group I; P = .01 and P < .01, respectively). Administration of aprotinin or alpha-tocopherol prior to I/R resulted in significant increases in SOD and CAT levels compared with the I/R group (P < .05 each). Compared to the I/R group, significant decreases in plasma AST, ALT, and LDH levels were observed both in the aprotinin and in the alpha-tocopherol group (P < .05). Histological evaluation revealed the injury grade to be relatively lower among groups III and IV compared to group I.

DISCUSSION

In conclusion, rat hepatic structures in aprotinin and alpha-tocopherol administered groups were well protected. Therefore, aprotinin may provide protection against the adverse effects of I/R injury in liver transplantation.

Efficacy of FDA-approved hemostatic drugs to improve survival and reduce bleeding in rat models of uncontrolled hemorrhage

Several FDA-approved intravenous drugs are used to reduce surgical bleeding. This series of studies tested whether these drugs (aprotinin, desmopressin, tranexamic acid, epsilon-aminocaproic acid) could reduce bleeding due to traumatic injuries in two models of uncontrolled hemorrhage in rats. In the first phase of each study, a nonlethal tail bleeding model was used that incorporated limited fluid resuscitation (lactate Ringer's solution). Four doses of vehicle or the test substance were given successively with bleeding time and blood loss measured after each dose. In the second phase of each study, a lethal liver injury was produced by excising a section of the median lobe (approximately 0.8% of body weight) and an infusion of either vehicle or the test substance was immediately begun. This model included aggressive fluid resuscitation and a severe dilutional coagulopathy. Blood loss, survival time and mortality rate were recorded. Three studies were performed, testing each of the drugs singly and in combination. None of the drugs significantly reduced either bleeding time or blood loss in the tail bleeding model, nor were blood loss, survival time or mortality rate altered in the liver injury model. Taken together, these results suggest that these FDA-approved drugs, when used either singly or in combination, are not efficacious in these models of traumatic uncontrolled hemorrhage.

The Use of Fresh Whole Blood in Massive Transfusion

BACKGROUND

Most indications for whole blood transfusion are now well managed exclusively with blood component therapy, yet the use of fresh whole blood for resuscitating combat casualties has persisted in the U.S. military.

METHODS

Published descriptions of whole blood use in military and civilian settings were compared with use of whole blood at the 31st Combat Support Hospital (31st CSH) stationed in Baghdad in 2004-2005.

FINDINGS

Concerns about logistics, safety, and relative efficacy of whole blood versus component therapy have argued against the use of whole blood in most settings. However, military physicians have observed some distinct advantages in fresh warm whole blood over component therapy during the massive resuscitation of acidotic, hypothermic, and coagulopathic trauma patients. In this critical role, fresh whole blood was eventually incorporated as an adjunct into a novel whole-blood-based massive transfusion protocol.

CONCLUSIONS

Under extreme and austere circumstances, the risk:benefit ratio of whole blood transfusion favors its use. Fresh whole blood may, at times, be advantageous even when conventional component therapy is available.