Effects of hemorrhagic shock and rhabdomyolysis on renal microcirculation, oxygenation and function in a female swine model.

BACKGROUND: Hemorrhagic shock (HS) and rhabdomyolysis (RM) are two important risk factors of acute kidney injury (AKI) after severe trauma, however the effects of the combination of RM and HS on kidney function are unknown. The purpose of this study was to determine the impact of RM and HS on renal function, oxygenation, perfusion and morphology, in a pig model. METHODS: Forty-seven female pigs were divided into 5 groups: sham, RM, HS, HS and moderate RM (RM4/HS), HS and severe RM (RM8/HS). RM was induced by intramuscular injection of Glycerol 50% with a moderate dose (4 ml/kg for RM4/HS group) or a high dose (8 ml/kg for RM and RM8/HS groups). Among animals with HS, after 90 min of hemorrhage, animals were resuscitated with fluid followed by transfusion of the withdrawn blood. Animals were followed for 48 hours. Macro and microcirculatory parameters measurements were performed. RESULTS: RM alone induced a decrease in creatinine clearance at 48 hours (19 (0-41) vs 102 (56-116) ml/min for RM and SHAM respectively; p = 0.0006) without alteration in renal perfusion and oxygenation. HS alone impaired temporarily renal microcirculation, function and oxygenation that were restored with fluid resuscitation. RM4/HS and RM8/HS groups induced greater impairment of renal microcirculation and function than HS alone at the end of blood spoliation that were not improved by fluid resuscitation. Mortality was increased in RM8/HS and RM4/HS groups in the first 48 hours (73% vs 56% vs 9% for RM8/HS, RM4/HS and HS groups respectively). CONCLUSIONS: The combination of HS and RM induced an early deleterious effect on renal microcirculation, function and oxygenation with decreased response to resuscitation and transfusion compared with HS or RM alone.

Femoral blood gas analysis, another tool to assess hemorrhage severity following trauma: an exploratory prospective study.

BACKGROUND: Veno-arterial carbon dioxide tension difference (ΔPCO2) and mixed venous oxygen saturation (SvO2) have been shown to be markers of the adequacy between cardiac output and metabolic needs in critical care patients. However, they have hardly been assessed in trauma patients. We hypothesized that femoral ΔPCO2 (ΔPCO2 fem) and SvO2 (SvO2 fem) could predict the need for red blood cell (RBC) transfusion following severe trauma. METHODS: We conducted a prospective and observational study in a French level I trauma center. Patients admitted to the trauma room following severe trauma with an Injury Severity Score (ISS) > 15, who had arterial and venous femoral catheters inserted were included. ΔPCO2 fem, SvO2 fem and arterial blood lactate were measured over the first 24 h of admission. Their abilities to predict the transfusion of at least one pack of RBC (pRBCH6) or hemostatic procedure during the first six hours of admission were assessed using receiver operating characteristics curve. RESULTS: 59 trauma patients were included in the study. Median ISS was 26 (22-32). 28 patients (47%) received at least one pRBCH6 and 21 patients (35,6%) had a hemostatic procedure performed during the first six hours of admission. At admission, ΔPCO2 fem was 9.1 ± 6.0 mmHg, SvO2 fem 61.5 ± 21.6% and blood lactate was 2.7 ± 1.9 mmol/l. ΔPCO2 fem was significantly higher (11.6 ± 7.1 mmHg vs. 6.8 ± 3.7 mmHg, P = 0.003) and SvO2 fem was significantly lower (50 ± 23 mmHg vs. 71.8 ± 14.1 mmHg, P < 0.001) in patients who were transfused than in those who were not transfused. Best thresholds to predict pRBCH6 were 8.1 mmHg for ΔPCO2 fem and 63% for SvO2 fem. Best thresholds to predict the need for a hemostatic procedure were 5.9 mmHg for ΔPCO2 fem and 63% for SvO2 fem. Blood lactate was not predictive of pRBCH6 or the need for a hemostatic procedure. CONCLUSION: In severe trauma patients, ΔPCO2 fem and SvO2 fem at admission were predictive for the need of RBC transfusion and hemostatic procedures during the first six hours of management while admission lactate was not. ΔPCO2 fem and SvO2 fem appear thus to be more sensitive to blood loss than blood lactate in trauma patients, which might be of importance to early assess the adequation of tissue blood flow with metabolic needs.

Renal Microcirculation and Function in a Pig Model of Hemorrhagic Shock Resuscitation with Norepinephrine.

Rationale: Norepinephrine (NE) is commonly used in combination with fluid during resuscitation of hemorrhagic shock, but its impact on kidney microcirculation, oxygenation, and function is still unknown in this setting. Objectives: During hemorrhagic shock resuscitation, does a combination of fluid and NE affect kidney oxygenation tension, kidney microcirculatory perfusion, and 48-hour kidney function, as compared with fluid alone? Methods: Hemorrhagic shock was induced in 24 pigs, and 8 pigs were included as a sham group. Resuscitation of hemorrhagic shock was performed, using a closed-loop device, either by fluid alone (0.9% NaCl; fluid group) or associated with the administration of NE at two doses (moderate dose: mean rate of 0.64 µg ⋅ kg-1 ⋅ min-1; high dose: mean rate of 1.57 µg ⋅ kg-1 ⋅ min-1) to obtain a target systolic arterial pressure of 80 to 90 mm Hg. Resuscitation was followed by transfusion of the withdrawn blood. Measurements and Main Results: The amount of fluid required to reach the target systolic arterial pressure was lower in the NE groups than in the fluid group, with subsequently less hemodilution. NE restored kidney microcirculation, oxygenation, and function in a manner comparable to that achieved with fluid resuscitation alone. There were no histologic differences between animals resuscitated with fluid and those resuscitated with NE. Conclusions: In pigs with hemorrhagic shock, resuscitation with a combination of NE and fluid restored kidney microcirculation and oxygenation, as well as renal function, in a manner comparable to fluid resuscitation alone and without differences between the two NE doses. NE administration led to a fluid volume-sparing effect with subsequently less hemodilution.

Long-term outcome following blunt cerebrovascular injuries: occurrence of ischemic complications, treatment, and outcome.

PURPOSE: Blunt cerebrovascular injuries (BCVI) are a rare but serious complication after trauma. Among patients with BCVI, neurological status is altered in 30% of cases and the prognosis seems to be associated with ischemic complications. The aim of this study was to assess the long-term outcome of BCVI-associated ischemic events. METHODS: This retrospective cohort study (2011-2017) included all patients admitted for severe trauma with identified BCVI in two level-1 trauma centers. Patients were considered to have a poor neurological outcome with a GOS-E between 2 and 5 and a good neurological outcome with GOS-E between 6 and 8. A multivariate logistic regression identified risk factors for poor neurological outcome at 1 year. RESULTS: Of the 6,294 patients admitted in both trauma centers between 2011 and 2017, 81 patients presenting BCVI were identified (incidence of 1.3%). The median age was 35 years (24-44) with a median Injury Severity Score of 28 (17-41). 29 patients (50%) had a good neurological prognosis, while 25 patients (43%) had a poor neurological prognosis at 1 year. Ischemic stroke occurred in 11 patients (13.6%) within a median time of 2 days (2-2.5). No ischemic stroke occurred in the first year after ICU discharge in both groups. In our study, good prognosis at 1 year was not associated with ischemic complications [3 (10) vs 3 (12) p = 1]. CONCLUSION: Ischemic complications after BCVI are rare, occur within the first week and do not seem to impact independently the 1-year neurological prognosis.

[Complex management of type 2 heparin-induced thrombocytopenia in patients with major bleeding tendency: two case report]. / Prise en charge de la thrombopénie induite par l'héparine immuno-allergique de type 2 au travers de deux cas cliniques chez des patients à risque hémorragique majeur.

Type 2 heparin-induced thrombocytopenia (HIT 2) is a rare pro-thrombotic disorder occurring in patients treated with heparin. It is defined as a clinical-biological syndrome associating the sudden onset of a thrombocytopenia, characterized by a drop of more than 50% of the initial platelet count, and thrombosis. We report two cases of HIT 2 occurring in patients with major bleeding tendency. The first HIT occurred in a patient whose management, in accordance with current guidelines, made it possible to control the thrombocytopenia and the anticoagulation despite the complexity of adapting and monitoring treatments in the context of recent cerebral hemorrhage. The second refers to an autoimmune HIT, which occurred in a patient whose management required the use of alternative therapies to the standard treatments suggested for HIT 2, to correct the severe refractory thrombocytopenia.