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1.
J Am Assoc Lab Anim Sci ; 59(3): 322-327, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32204749

RESUMO

Accurate assessment of coagulation in porcine studies is essential. We sought to establish normal values for porcine rotational thromboelastometry (ROTEM) according to the American Society for Veterinary Clinical Pathology guidelines and to assess the effects of various preanalytical parameters on those measurements. Healthy Yorkshire-cross pigs (n = 81; 46 males and 35 females) were anesthetized. By using a 18-gauge needle attached to a vacuum phlebotomy tube, blood was acquired from the cranial vena cava. Tubes were filled in the following order: evacuation clot tube, EDTA tube, heparin tube, and 2 citrate tubes. The citrate tubes were randomly assigned to 30 min with or without constant agitation on a rocker. The following parameters were reported according to the manufacturer's recommendations: clotting time, clot formation time, α, (tangent to the clot formation curve when the clot firmness is 20 mm), clot firmness after 10 and 20 min, maximal clot firmness, maximum lysis, and lysis indexes at 30 and 45 min. Reference intervals were reported as mean ± 2 SD (parametric distribution) or 2.5th and 97.5th percentile of the population's results (nonparametric distribution). The effects of sex, sampling order, and agitation on ROTEM results were analyzed through linear regression. Neither sex nor sample agitation influenced any of the ROTEM parameters. Combined reference intervals were established for each ROTEM parameter by pooling data from the nonagitated tubes for both male and female pigs. This study is the first to establish ROTEM reference intervals from a large number of male and female adult Yorkshire-cross pigs and to provide a detailed description of preanalytical sample processing.

2.
Mil Med ; 185(Suppl 1): 42-49, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-32074339

RESUMO

INTRODUCTION: External cooling of ischemic limbs has been shown to have a significant protective benefit for durations up to 4 hours. MATERIALS AND METHODS: It was hypothesized that this benefit could be extended to 8 hours. Six swine were anesthetized and instrumented, then underwent a 25% total blood volume hemorrhage. Animals were randomized to hypothermia or normothermia followed by 8 hours of Zone 3 resuscitative endovascular balloon occlusion of the aorta, then resuscitation with shed blood, warming, and 3 hours of critical care. Physiologic parameters were continuously recorded, and laboratory specimens were obtained at regular intervals. RESULTS: There were no significant differences between groups at baseline. There were no significant differences between creatine kinase in the hypothermia group when compared to the normothermia group (median [IQR] = 15,206 U/mL [12,476-19,987] vs 23,027 U/mL [18,745-26,843]); P = 0.13) at the end of the study. Similarly, serum myoglobin was also not significantly different in the hypothermia group after 8 hours (7,345 ng/mL [5,082-10,732] vs 5,126 ng/mL [4,720-5,298]; P = 0.28). No histologic differences were observed in hind limb skeletal muscle. CONCLUSION: While external cooling during prolonged Zone 3 resuscitative endovascular balloon occlusion of the aorta appears to decrease ischemic muscle injury, this benefit appears to be time dependent. As the ischemic time approaches 8 hours, the benefit from hypothermia decreases.

3.
J Trauma Acute Care Surg ; 88(2): 298-304, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31996655

RESUMO

BACKGROUND: Partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) and intermittent REBOA (iREBOA) are techniques to extend the therapeutic duration of REBOA by balloon titration for distal flow or cyclical balloon inflation/deflation to allow transient distal flow, respectively. We hypothesized that manually titrated pREBOA would reduce blood losses and ischemic burden when compared with iREBOA. METHODS: Following 20% blood volume controlled hemorrhage, 10 anesthetized pigs underwent uncontrolled hemorrhage from the right iliac artery and vein. Once in hemorrhagic shock, animals underwent 15 minutes of complete zone 1 REBOA followed by 75 minutes of either pREBOA or iREBOA (n = 5/group). After 90 minutes, definitive hemorrhage control was obtained, animals were resuscitated with the remaining collected blood, and then received 2 hours of critical care. RESULTS: There were no differences in mortality. Animals randomized to iREBOA spent a larger portion of the time at full occlusion when compared with pREBOA (median, 70 minutes; interquartile range [IQR], 70-80 vs. median, 20 minutes; IQR, 20-40, respectively; p = 0.008). While the average blood pressure during the intervention period was equivalent between groups, this was offset by large fluctuations in blood pressure and significantly more rescue occlusions for hypotension with iREBOA. Despite lower maximum aortic flow rates, the pREBOA group tolerated a greater total amount of distal aortic flow during the intervention period (median, 20.9 L; IQR, 20.1-23.0 vs. median, 9.8 L; IQR, 6.8-10.3; p = 0.03) with equivalent abdominal blood losses. Final plasma lactate and creatinine concentrations were equivalent, although iREBOA animals had increased duodenal edema on histology. CONCLUSION: Compared with iREBOA, pREBOA reduced the time spent at full occlusion and the number of precipitous drops in proximal mean arterial pressure while delivering more distal aortic flow but not increasing total blood loss in this highly lethal injury model. Neither technique demonstrated a survival benefit. Further refinement of these techniques is necessary before clinical guidelines are issued.


Assuntos
Oclusão com Balão/métodos , Procedimentos Endovasculares/métodos , Ressuscitação/métodos , Choque Hemorrágico/terapia , Ferimentos e Lesões/terapia , Animais , Aorta/cirurgia , Oclusão com Balão/efeitos adversos , Oclusão com Balão/instrumentação , Modelos Animais de Doenças , Procedimentos Endovasculares/efeitos adversos , Procedimentos Endovasculares/instrumentação , Humanos , Masculino , Ressuscitação/efeitos adversos , Ressuscitação/instrumentação , Choque Hemorrágico/etiologia , Choque Hemorrágico/mortalidade , Análise de Sobrevida , Sus scrofa , Fatores de Tempo , Índices de Gravidade do Trauma , Resultado do Tratamento , Ferimentos e Lesões/complicações , Ferimentos e Lesões/diagnóstico
5.
Artigo em Inglês | MEDLINE | ID: mdl-31804420

RESUMO

BACKGROUND: Partial resuscitative endovascular balloon occlusion of the aorta (pREBOA) and intermittent-REBOA (iREBOA) are techniques to extend the therapeutic duration of REBOA by balloon titration for distal flow or cyclical balloon inflation/deflation to allow transient distal flow, respectively. We hypothesized that manually-titrated pREBOA would reduce blood losses and ischemic burden when compared to iREBOA. METHODS: Following 20% blood volume controlled hemorrhage, 10 anesthetized pigs underwent uncontrolled hemorrhage from the right iliac artery and vein. Once in hemorrhagic shock, animals underwent 15 minutes of complete Zone 1 REBOA followed by 75 minutes of either pREBOA or iREBOA (N=5/group). After 90 minutes, definitive hemorrhage control was obtained, animals were resuscitated with the remaining collected blood, and then received 2 hours of critical care. RESULTS: There were no differences in mortality. Animals randomized to iREBOA spent a larger portion of the time at full occlusion when compared to pREBOA (median [IQR]; 70 minutes [70, 80] versus 20 minutes [20, 40] respectively; p=0.008). While the average blood pressure during the intervention period was equivalent between groups, this was offset by large fluctuations in blood pressure and significantly more rescue occlusions for hypotension with iREBOA. Despite lower maximum aortic flow rates, the pREBOA group tolerated a greater total amount of distal aortic flow during the intervention period (median [IQR]; 20.9 L [20.1-23.0] vs 9.8 L [6.8-10.3]; p=0.03) with equivalent abdominal blood losses. Final plasma lactate and creatinine concentrations were equivalent, although iREBOA animals had increased duodenal edema on histology. CONCLUSION: Compared to iREBOA, pREBOA reduced the time spent at full occlusion and the number of precipitous drops in proximal MAP while delivering more distal aortic flow but not increasing total blood loss in this highly lethal injury model. Neither technique demonstrated a survival benefit. Further refinement of these techniques is necessary before clinical guidelines are issued. LEVEL OF EVIDENCE: III STUDY TYPE: Therapeutic.

6.
Artigo em Inglês | MEDLINE | ID: mdl-31576422

RESUMO

PURPOSE: While resuscitative endovascular balloon occlusion of the aorta (REBOA) is contraindicated in patients with aortic injuries, this technique may benefit poly-trauma patients with less extreme thoracic injuries. The purpose of this study was to characterize the effects of thoracic injury on hemodynamics during REBOA and the changes in pulmonary contusion over time in a swine model. METHODS: Twelve swine were anesthetized, instrumented, and randomized to receive either a thoracic injury with 5 impacts to the chest or no injury. All animals underwent controlled hemorrhage of 25% blood volume followed by 45 min of Zone 1 REBOA. Animals were then resuscitated with shed blood, observed during a critical care period, and euthanized after 6 h of total experimental time. RESULTS: There were no differences between the groups at baseline. The only difference after 6 h was a lower hemoglobin in the thoracic trauma group (8.4 ± 0.8 versus 9.4 ± 0.6 g/dL, P = 0.04). The average proximal mean arterial pressures were significantly lower in the thoracic trauma group during aortic occlusion [103 (98-108) versus 117 (115-124) mmHg, P = 0.04]. There were no differences between the pulmonary contusion before REBOA and at the end of the experiment in size (402 ± 263 versus 356 ± 291 mL, P = 0.782) or density (- 406 ± 127 versus - 299 ± 175 HFU, P = 0.256). CONCLUSIONS: Thoracic trauma blunted the proximal arterial pressure augmentation during REBOA but had minimal impacts on resuscitative outcomes. This initial study indicates that REBOA does not seem to exacerbate pulmonary contusion in swine, but blunt thoracic injuries may attenuate the expected rises in proximal blood pressure during REBOA.

7.
Shock ; 2019 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-31389905

RESUMO

INTRODUCTION: Tranexamic acid (TXA) improves survival in traumatic hemorrhage, but difficulty obtaining intravenous (IV) access may limit its use in austere environments, given its incompatibility with blood products. The bioavailability of intramuscular (IM) TXA in a shock state is unknown. We hypothesized that IM and IV administration have similar pharmacokinetics and ability to reverse in vitro hyperfibrinolysis in a swine controlled-hemorrhage model. METHODS: Twelve Yorkshire cross swine were anesthetized, instrumented, and subjected to a 35% controlled hemorrhage, followed by resuscitation. During hemorrhage, they were randomized to receive a 1 g IV TXA infusion over 10 minutes, 1 g IM TXA in two 5 mL injections, or 10 mL normal saline IM injection as a placebo group to assess model adequacy. Serum TXA concentrations were determined using liquid chromatography-mass spectrometry, and plasma samples supplemented with tissue plasminogen activator (tPA) were analyzed by rotational thromboelastometry (ROTEM). RESULTS: All animals achieved class III shock. There was no difference in the concentration-time areas under the curve (AUC) between TXA given by either route. The absolute bioavailability of IM TXA was 97%. IV TXA resulted in a higher peak serum concentration during the infusion, with no subsequent differences. Both IV and IM TXA administration caused complete reversal of in vitro tPA-induced hyperfibrinolysis. CONCLUSION: The pharmacokinetics of IM TXA were similar to IV TXA during hemorrhagic shock in our swine model. IV administration resulted in a higher serum concentration only during the infusion, but all levels were able to successfully correct in vitro hyperfibrinolysis. There was no difference in total body exposure to equal doses of TXA between the two routes of administration. IM TXA may prove beneficial in scenarios where difficulty establishing dedicated IV access could otherwise limit or delay its use.

8.
JFMS Open Rep ; 5(2): 2055116919863175, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31384478

RESUMO

Objectives: The aims of this study were to update the prevalence of different feline blood types in the Lyon (France) area, as well as to determine the risk of mismatched transfusion (MT) and neonatal isoerythrolysis (NI) in kittens with parents of unknown blood type. Methods: Blood samples were obtained from blood donor cats and cats admitted to an intensive care unit in Lyon. AB blood typing was performed using an immunochromatographic strip. The risk of MT was estimated by adding the risk of a major transfusion reaction and the risk of a minor transfusion reaction. The risk of NI was estimated according the equation (p²)(q²) + 2pq(q²), with q being the b allele frequency and p = 1 - q. The results were analysed by absolute and relative frequency analysis and multivariate analysis. Results: The cohort study population included 320 non-pedigree cats and 37 pedigree cats. The prevalence of blood types A, B and AB was 84.3%, 14.0% and 1.7%, respectively. Considering non-pedigree cats, the prevalence of types A, B and AB was 83.7%, 14.4% and 1.9%, respectively. There were no significant differences of blood type distribution by sex (P = 0.73) or by breed (P = 0.90). Based on these percentages, the risks of MT and NI in non-pedigree cats were 24.3% and 12.3%, respectively. Conclusions and relevance: The prevalence of type B cats is high in the Lyon area and associated with high risks of MT and NI. These results confirm the importance of performing blood typing prior to any blood transfusion or mating.

9.
Injury ; 50(11): 1908-1914, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31466700

RESUMO

INTRODUCTION: Trauma patients are predisposed to kidney injury. We hypothesized that in shock, zone 3 REBOA would increase renal blood flow (RBF) compared to control and that a period of zone 3 occlusion following zone 1 occlusion would improve renal function compared to zone 1 occlusion alone. MATERIALS AND METHODS: Twenty-four anesthetized swine underwent hemorrhagic shock, 45 min of zone 1 REBOA (Z1, supraceliac), zone 3 REBOA (Z3, infrarenal), or no intervention (control) followed by resuscitation with shed blood and 5 h of critical care. In a fourth group (Z1Z3), animals underwent 55 min of zone 3 REBOA following zone 1 occlusion. Physiologic parameters were recorded, blood and urine were collected at specified intervals. RESULTS: During critical care, there were no differences in RBF between the Z1 and Z3 groups. The average RBF during critical care in Z1Z3 was significantly lower than in Z3 alone (98.2 ±â€¯23.9 and 191.9 ±â€¯23.7 mL/min; p = 0.046) and not different than Z1. There was no difference in urinary neutrophil gelatinase-associated lipocalin-to-urinary creatinine ratio between Z1 and Z1Z3. Animals in the Z1Z3 group had a significant increase in the ratio at the end of the experiment compared to baseline [median (IQR)] [9.2 (8.2-13.2) versus 264.5 (73.6-1174.6)]. Following Z1 balloon deflation, RBF required 45 min to return to baseline. CONCLUSION: Neither zone 3 REBOA alone nor zone 3 REBOA following zone 1 REBOA improved renal blood flow or function. Following zone 1 occlusion, RBF is restored to baseline levels after approximately 45 min.

10.
Front Vet Sci ; 6: 197, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31275952

RESUMO

While hemorrhagic shock might be the result of various conditions, hemorrhage control and resuscitation are the corner stone of patient management. Hemorrhage control can prove challenging in both the acute care and surgical settings, especially in the abdomen, where no direct pressure can be applied onto the source of bleeding. Resuscitative endovascular balloon occlusion of the aorta (REBOA) has emerged as a promising replacement to resuscitative thoracotomy (RT) for the management of non-compressible torso hemorrhage in human trauma patients. By inflating a balloon at specific levels (or zones) of the aorta to interrupt blood flow, hemorrhage below the level of the balloon can be controlled. While REBOA allows for hemorrhage control and augmentation of blood pressure cranial to the balloon, it also exposes caudal tissue beds to ischemia and the whole body to reperfusion injury. We aim to introduce the advantages of REBOA while reviewing known limitations. This review outlines a step-by-step approach to REBOA implementation, and discusses common challenges observed both in human patients and during translational large animal studies. Currently accepted and debated indications for REBOA in humans are discussed. Finally, we review possible applications for veterinary patients and how REBOA has the potential to be translated into clinical veterinary practice.

11.
J Trauma Acute Care Surg ; 87(3): 590-598, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31145381

RESUMO

BACKGROUND: The cardiac effects of resuscitative endovascular balloon occlusion of the aorta (REBOA) are largely unknown. We hypothesized that increased afterload from REBOA would lead to cardiac injury, and that partial flow using endovascular variable aortic control (EVAC) would mitigate this injury. METHODS: Eighteen anesthetized swine underwent controlled 25% blood volume hemorrhage. Animals were randomized to either Zone 1 REBOA, Zone 1 EVAC, or no intervention (control) for 45 minutes. Animals were then resuscitated with shed blood, observed during critical care, and euthanized after a 6-hour total experimental time. Left ventricular function was measured with a pressure-volume catheter, and blood samples were drawn at routine intervals. RESULTS: The average cardiac output during the intervention period was higher in the REBOA group (9.3 [8.6-15.4] L/min) compared with the EVAC group (7.2 [5.8-8.0] L/min, p = 0.01) and the control group (6.8 [5.8-7.7] L/min, p < 0.01). At the end of the intervention, the preload recruitable stroke work was significantly higher in both the REBOA and EVAC groups compared with the control group (111.2 [102.5-148.6] and 116.7 [116.6-141.4] vs. 67.1 [62.7-87.9], p = 0.02 and p < 0.01, respectively). The higher preload recruitable stroke work was maintained throughout the experiment in the EVAC group, but not in the REBOA group. Serum troponin concentrations after 6 hours were higher in the REBOA group compared with both the EVAC and control groups (6.26 ± 5.35 ng/mL vs 0.92 ± 0.61 ng/mL and 0.65 ± 0.38 ng/mL, p = 0.05 and p = 0.03, respectively). Cardiac intramural hemorrhage was higher in the REBOA group compared with the control group (1.67 ± 0.46 vs. 0.17 ± 0.18, p = 0.03), but not between the EVAC and control groups. CONCLUSION: In a swine model of hemorrhagic shock, complete aortic occlusion resulted in cardiac injury, although there was no direct decrease in cardiac function. EVAC mitigated the cardiac injury and improved cardiac performance during resuscitation and critical care.


Assuntos
Aorta , Oclusão com Balão , Procedimentos Endovasculares/métodos , Isquemia Miocárdica/prevenção & controle , Ressuscitação/métodos , Animais , Aorta/fisiopatologia , Aorta/cirurgia , Oclusão com Balão/efeitos adversos , Oclusão com Balão/métodos , Modelos Animais de Doenças , Feminino , Masculino , Isquemia Miocárdica/etiologia , Choque Hemorrágico/terapia , Suínos , Função Ventricular Esquerda
12.
J Trauma Acute Care Surg ; 86(4): 694-701, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30633103

RESUMO

BACKGROUND: Potassium-binding polymers have shown promising results in an anephric porcine hyperkalemia model. The benefits of the polymer in a clinically relevant injury model remain unknown. We hypothesized that potassium-binding cartridges would control serum potassium concentration in a porcine hemorrhagic shock model with supraceliac aortic occlusion and a limb crush injury. METHODS: Ten Yorkshire-cross swine were anesthetized and instrumented. Pigs underwent splenectomy and bilateral nephrectomy. Hemorrhagic shock was induced for 30 minutes while a leg compression device was applied. Pigs underwent supraceliac aortic occlusion for 60 minutes and were resuscitated with shed blood. The leg compression device was removed 20 minutes after balloon deflation. After 20 minutes of reperfusion, animals were randomized to extracorporeal circulation with (treatment) or without (control) the potassium binding cartridges. In both groups, blood was circulated through a hemodialyzer with a peristaltic pump. In the treatment group, the ultrafiltrate was diverted from the hemodialyzer through cartridges containing the polymer and returned to the extracorporeal circuit. Animals were resuscitated with 0.9% saline boluses and a norepinephrine infusion. The change in serum potassium concentration (ΔK) was calculated as serum [K]T390 - serum [K]T0. RESULTS: There was a significant difference in serum potassium concentration between groups (p < 0.001). ΔK was significantly higher in the control than the treatment group (3.75 [3.27-4.42] and 1.15 [0.62-1.59] mmol/L, respectively; p = 0.03). There were no differences in mean arterial pressure (p = 0.14), isotonic crystalloids requirement (p = 0.51), or norepinephrine dose (p = 0.83) between groups. Serum lactate concentration was significantly higher in the control group (p < 0.001). At the end of the experiment, the [K] was reduced by 25% (24.9%-27.8%) across the cartridges. CONCLUSION: The cartridges controlled serum potassium concentrations without dialysate and retained potassium binding capabilities over 4 hours. There were no deleterious effects on hemodynamic parameters. Those cartridges might be beneficial adjuncts for hyperkalemia management in austere environments. LEVEL OF EVIDENCE: Translational science study, level I.

13.
Mil Med ; 184(5-6): e298-e302, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30371879

RESUMO

INTRODUCTION: Low distal aortic flow via partial aortic occlusion (AO) may mitigate ischemia induced by resuscitative endovascular balloon occlusion of the aorta (REBOA). We compared endocrine effects of a novel simulated partial AO strategy, endovascular variable aortic control (EVAC), with simulated REBOA in a swine model. MATERIALS AND METHODS: Aortic flow in 20 swine was routed from the supraceliac aorta through an automated extracorporeal circuit. Following liver injury-induced hemorrhagic shock, animals were randomized to control (unregulated distal flow), simulated REBOA (no flow, complete AO), or simulated EVAC (distal flow of 100-300 mL/min after 20 minutes of complete AO). After 90 minutes, damage control surgery, resuscitation, and full flow restoration ensued. Critical care was continued for 4.5 hours or until death. RESULTS: Serum angiotensin II concentration was higher in the simulated EVAC (4,769 ± 624 pg/mL) than the simulated REBOA group (2649 ± 429) (p = 0.01) at 180 minutes. There was no detectable difference in serum renin [simulated REBOA: 231.3 (227.9-261.4) pg/mL; simulated EVAC: 294.1 (231.2-390.7) pg/mL; p = 0.27], aldosterone [simulated EVAC: 629 (454-1098), simulated REBOA: 777 (575-1079) pg/mL, p = 0.53], or cortisol (simulated EVAC: 141 ± 12, simulated REBOA: 127 ± 9 ng/mL, p = 0.34) concentrations between groups. CONCLUSIONS: Simulated EVAC was associated with higher serum angiotensin II, which may have contributed to previously reported cardiovascular benefits. Future studies should evaluate the renal effects of EVAC and the concomitant therapeutic use of angiotensin II.


Assuntos
Aorta/cirurgia , Oclusão com Balão/efeitos adversos , Sistema Endócrino/enzimologia , Aldosterona/análise , Aldosterona/sangue , Angiotensina II/análise , Angiotensina II/sangue , Animais , Aorta/enzimologia , Oclusão com Balão/métodos , Modelos Animais de Doenças , Sistema Endócrino/irrigação sanguínea , Hidrocortisona/análise , Hidrocortisona/sangue , Renina/análise , Renina/sangue , Estatísticas não Paramétricas , Suínos
14.
Mil Med ; 184(3-4): 81-83, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30215751

RESUMO

Trauma-induced acute kidney injury (AKI) has affected many U.S. warfighters throughout history. We seek to provide a historical review of the epidemiology of combat-acquired AKI and to highlight the importance of adapting current renal replacement therapy (RRT) capabilities to prepare for the next armed conflict. While severe AKI was rare in the recent conflicts in Iraq and Afghanistan, an analysis of prior wars suggests that it will be more common in future combat operations characterized by prolonged evacuation times, limited resuscitation capabilities, and delayed aeromedical evacuation. Therefore, the military community must develop RRT capabilities to satisfy the demands of prolonged field care and austere environments. We propose a series of solutions such as re-enforcing forward deployment of conventional RRT capabilities as well as novel therapies such as improvised dialysis systems or sorbent-based RRT.


Assuntos
Lesão Renal Aguda/terapia , Terapia de Substituição Renal/métodos , Lesão Renal Aguda/etiologia , Distúrbios de Guerra/complicações , Distúrbios de Guerra/terapia , Previsões/métodos , Humanos , Terapia de Substituição Renal/tendências
15.
Shock ; 51(5): 659-666, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-29877961

RESUMO

BACKGROUND: The resuscitation of patients in shock is materially intensive and many patients are refractory to maximal therapy. We hypothesized that partial inflation of an intra-aortic balloon, termed Endovascular Perfusion Augmentation for Critical Care (EPACC), would minimize material requirements while improving physiologic metrics. METHODS: Swine underwent a 25% controlled bleed and 45 min of complete aortic occlusion to create a severe ischemia-reperfusion shock state. Animals received either standardized critical care (SCC) composed of IV fluids and norepinephrine delivered through an algorithmically controlled platform or EPACC in addition to SCC. Physiologic parameters were collected, and blood was sampled for analysis. Primary outcomes were total IV fluids and average MAP during the critical care phase. Differences (P < 0.05) were measured with t test (continuous data) and Wilcoxon rank-sum test (ordinal data). RESULTS: There were no differences in baseline characteristics. There were no differences in the maximum lactate; however, animals in the EPACC group had a higher average MAP (EPACC 65 mmHg, 95% confidence interval [CI], 65-66; SCC 60 mmHg, 95% CI, 57-63; P < 0.01) and remained within goal MAP for a greater period of time (EPACC 95.3%, 95% CI, 93.2-97.4; SCC 51.0%, 95% CI, 29.5-72.6; P < 0.01). EPACC animals required less IV fluids when compared with the SCC group (EPACC 21 mL/kg, 95% CI, 0-42; SCC 96 mL/kg, 95% CI, 76-117; P < 0.01). There were no differences in final lactate. Animals in the EPACC group had a higher final creatinine (EPACC 2.3 mg/dL, 95% CI, 2.1-2.5; SCC 1.7 mg/dL, 95% CI, 1.4-2.0; P < 0.01), but there were no differences in renal cellular damage on histology (P = 0.16). CONCLUSION: Using a swine model of severe shock, the addition of EPACC to SCC significantly reduced fluid resuscitation requirements and improved blood pressure. This is the first description of a new therapy for patients in refractory shock or in resource-limited settings.

16.
J Spec Oper Med ; 19(4): 80-84, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31910476

RESUMO

BACKGROUND: Intravenous (IV) tranexamic acid (TXA) is an adjunct for resuscitation in hemorrhagic shock; however, IV access in these patients may be difficult or impossible. Intraosseous (IO) or intramuscular (IM) administration could be quickly performed with minimal training. We investigated the pharmacokinetics of TXA via IV, IO, and IM routes in a swine model of controlled hemorrhagic shock. METHODS: Fifteen swine were anesthetized and bled of 35% of their blood volume before randomization to a single 1g/10mL dose of IV, IO, or IM TXA. Serial serum samples were obtained after TXA administration. These were analyzed with high-pressure liquid chromatography-mass spectrometry to determine drug concentration at each time point and define the pharmacokinetics of each route. RESULTS: There were no significant differences in baseline hemodynamics or blood loss between the groups. Peak concentration (Cmax) was significantly higher in IV and IO routes compared with IM (p = .005); however, the half-life of TXA was similar across all routes (p = .275). CONCLUSION: TXA administration via IO and IM routes during hemorrhagic shock achieves serum concentrations necessary for inhibition of fibrinolysis and may be practical alternatives when IV access is not available.


Assuntos
Choque Hemorrágico/tratamento farmacológico , Ácido Tranexâmico/administração & dosagem , Ácido Tranexâmico/farmacocinética , Administração Intravenosa , Animais , Modelos Animais de Doenças , Humanos , Infusões Intraósseas , Injeções Intramusculares , Suínos
17.
Shock ; 50(6): 677-683, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30427323

RESUMO

INTRODUCTION: The standard of care for refractory hyperkalemia is renal replacement therapy (RRT). However, traditional RRT requires specialized equipment, trained personnel, and large amounts of dialysate. It is therefore poorly suited for austere environments. We hypothesized that a simplified hemoperfusion system could control serum potassium concentration in a swine model of acute hyperkalemia. METHODS: Ten pigs were anesthetized and instrumented. A dialysis catheter was inserted. After bilateral nephrectomy, animals received intravenous potassium chloride and were randomized to the control or treatment group. In both groups, blood was pumped through an extracorporeal circuit (EC) with an in-line hemodialyzer. In the treatment arm, ultrafiltrate from the hemodialyzer was diverted through cartridges containing novel potassium binding beads and returned to the EC. Blood samples were obtained every 30 min for 6 h. RESULTS: Serum potassium concentration was significantly lower in the treatment than in the control group over time (P = 0.02). There was no difference in serum total calcium concentration for group or time (P = 0.13 and 0.44, respectively) or platelet count between groups or over time (P = 0.28 and 1, respectively). No significant EC thrombosis occurred. Two of five animals in the control group and none in the treatment group developed arrhythmias. All animals survived until end of experiment. CONCLUSIONS: A simplified hemoperfusion system removed potassium in a porcine model. In austere settings, this system could be used to temporize patients with hyperkalemia until evacuation to a facility with traditional RRT.


Assuntos
Hiperpotassemia/sangue , Hiperpotassemia/terapia , Animais , Pressão Arterial/fisiologia , Glicemia/efeitos dos fármacos , Glucose/uso terapêutico , Hemodinâmica/efeitos dos fármacos , Hemoperfusão , Hiperpotassemia/fisiopatologia , Masculino , Fenilefrina/farmacologia , Potássio/sangue , Taxa Respiratória/fisiologia , Suínos
18.
J Trauma Acute Care Surg ; 85(3): 519-526, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30142105

RESUMO

BACKGROUND: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is effective at limiting hemorrhage from noncompressible sources and restoring but causes progressive distal ischemia, supraphysiologic pressures, and increased cardiac afterload. Endovascular variable aortic control (EVAC) addresses these limitations, while still controlling hemorrhage. Previous work demonstrated improved outcomes following a 90-minute intervention period in an uncontrolled hemorrhage model. The present study compares automated EVAC to REBOA over an occlusion period reflective of contemporary REBOA usage. METHODS: Following instrumentation, 12 Yorkshire-cross swine underwent controlled 25% hemorrhage, a 45-minute intervention period of EVAC or REBOA, and subsequent resuscitation with whole blood and critical care for the remainder of a 6-hour experiment. Hemodynamics were acquired continuously, and laboratory parameters were assessed at routine intervals. Tissue was collected for histopathologic analysis. RESULTS: No differences were seen in baseline parameters. During intervention, EVAC resulted in more physiologic proximal pressure augmentation compared with REBOA (101 vs. 129 mm Hg; 95% confidence interval [CI], 105-151 mm Hg; p = 0.04). During critical care, EVAC animals required less than half the amount of crystalloid (3,450 mL; 95% CI, 1,215-5,684 mL] vs. 7,400 mL [95% CI, 6,148-8,642 mL]; p < 0.01) and vasopressors (21.5 ng/kg [95% CI, 7.5-35.5 ng/kg] vs. 50.5 ng/kg [95% CI, 40.5-60.5 ng/kg]; p = 0.05) when compared with REBOA animals. Endovascular variable aortic control resulted in lower peak and final lactate levels. Endovascular variable aortic control animals had less aortic hyperemia from reperfusion with aortic flow rates closer to baseline (36 mL/kg per minute [95% CI, 30-44 mL/kg per minute] vs. 51 mL/kg per minute [95% CI, 41-61 mL/kg per minute]; p = 0.01). CONCLUSIONS: For short durations of therapy, EVAC produces superior hemodynamics and less ischemic insult than REBOA in this porcine-controlled hemorrhage model, with improved outcomes during critical care. This study suggests EVAC is a viable strategy for in-hospital management of patients with hemorrhagic shock from noncompressible sources. Survival studies are needed to determine if these early differences persist over time.


Assuntos
Oclusão com Balão/métodos , Procedimentos Endovasculares/instrumentação , Traumatismo por Reperfusão/terapia , Animais , Aorta/patologia , Oclusão com Balão/efeitos adversos , Modelos Animais de Doenças , Feminino , Hemodinâmica/fisiologia , Hemorragia/prevenção & controle , Hemorragia/terapia , Ácido Láctico/metabolismo , Masculino , Reperfusão , Ressuscitação/métodos , Choque Hemorrágico/terapia , Suínos
19.
J Trauma Acute Care Surg ; 85(1): 101-107, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29965941

RESUMO

OBJECTIVES: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is an emerging technology to augment proximal blood pressure during the resuscitation of patients with noncompressible torso hemorrhage. Currently, placement choice, supraceliac (Zone 1) versus infrarenal (Zone 3) aorta, depends on injury patterns, but remains a highly debated topic. We sought to compare the proximal hemodynamic support provided by Zone 1 versus Zone 3 REBOA placement and the degree of hemodynamic instability upon reperfusion following intervention. METHODS: Eighteen anesthetized swine underwent controlled hemorrhage of 25% total blood volume, followed by 45 minutes of Zone 1 REBOA, Zone 3 REBOA, or no intervention (control). They were then resuscitated with shed blood, aortic balloons were deflated, and 5 hours of critical care ensued prior to euthanasia. Physiologic parameters were recorded continuously, and blood was drawn for analysis at specified intervals. Significance was defined as p < 0.05. RESULTS: There were no significant differences between groups at baseline or during the initial 30 minutes of hemorrhage. During the intervention period, average proximal MAP was significantly greater in Zone 1 animals when compared with Zone 3 animals (127.9 ± 1.3 vs. 53.4 ± 1.1 mm Hg) and greater in Zone 3 animals when compared with control animals (42.9 ± 0.9 mm Hg). Lactate concentrations were significantly higher in Zone 1 animals (9.6 ± 0.4 mmol/L) when compared with Zone 3 animals (5.1 ± 0.3 mmol/L) and control animals (4.2 ± 0.8 mmol/L). CONCLUSIONS: In our swine model of hemorrhagic shock, Zone 3 REBOA provided minimal proximal hemodynamic support when compared with Zone 1 REBOA, albeit with less ischemic burden and instability upon reperfusion. In cases of impending hemodynamic collapse, Zone 1 REBOA placement may be more efficacious regardless of injury pattern, whereas Zone 3 should be reserved only for relatively stable patients with ongoing distal hemorrhage.


Assuntos
Aorta/cirurgia , Oclusão com Balão/métodos , Procedimentos Endovasculares/métodos , Ressuscitação/métodos , Choque Hemorrágico/cirurgia , Animais , Oclusão com Balão/veterinária , Cuidados Críticos/métodos , Modelos Animais de Doenças , Procedimentos Endovasculares/veterinária , Feminino , Hemodinâmica/fisiologia , Masculino , Traumatismo por Reperfusão/etiologia , Ressuscitação/veterinária , Choque Hemorrágico/fisiopatologia , Choque Hemorrágico/veterinária , Suínos
20.
Artigo em Inglês | MEDLINE | ID: mdl-30020223

RESUMO

BACKGROUND: Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA) is effective at limiting hemorrhage from non-compressible sources and restoring, yet causes progressive distal ischemia, supraphysiologic pressures and increased cardiac afterload. Endovascular Variable Aortic Control (EVAC) addresses these limitations, while still controlling hemorrhage. Previous work demonstrated improved outcomes following a 90-minute intervention period in an uncontrolled hemorrhage model. The present study compares automated EVAC to REBOA over an occlusion period reflective of contemporary REBOA usage. METHODS: Following instrumentation, 12 Yorkshire-cross swine underwent controlled 25% hemorrhage, a 45-minute intervention period of EVAC or REBOA, and subsequent resuscitation with whole blood and critical care for the remainder of a six-hour experiment. Hemodynamics were acquired continuously and laboratory parameters were assessed at routine intervals. Tissue was collected for histopathologic analysis. RESULTS: No differences were seen in baseline parameters. During intervention, EVAC resulted in more physiologic proximal pressure augmentation compared to REBOA (101 mmHg vs 129 mmHg 95CI 105-151, p=0.04). During critical care, EVAC animals required less than half the amount of crystalloid (3450 ml 95CI 1215-5684 vs 7400 ml 95CI 6148-8642, p<0.01) and vasopressors (21.5 ng/kg 95CI 7.5-35.5 vs 50.5 ng/kg 95CI 40.5-60.5, p=0.05) when compared to REBOA animals. EVAC resulted in lower peak and final lactate levels. EVAC animals had less aortic hyperemia from reperfusion with aortic flow rates closer to baseline (36 ml/kg/min 95CI 30-44 vs 51 mL/kg/min 95CI 41-61, p=0.01). CONCLUSION: For short durations of therapy, EVAC produces superior hemodynamics and less ischemic insult than REBOA in this porcine controlled hemorrhage model, with improved outcomes during critical care. This study suggests EVAC is a viable strategy for in-hospital management of patients with hemorrhagic shock from non-compressible sources. Survival studies are needed to determine if these early differences persist over time. LEVEL OF EVIDENCE: 1 STUDY TYPE: Translational Science.

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