The Impact of Hemorrhagic Shock on Lung Ultrasound-Induced Pulmonary Capillary Hemorrhage.

OBJECTIVES: Lung ultrasound (LUS) exposure can induce pulmonary capillary hemorrhage (PCH), depending on biological and physical exposure parameters. This study was designed to investigate the variation in the LUS induction of PCH due to hemorrhagic shock, which itself can engender pulmonary injury. METHODS: Male rats were anesthetized with isoflurane in air. Shock was induced by withdrawal of 40% of the blood volume and assessed by the blood pressure detected by a femoral artery catheter and by blood glucose tests. B-mode ultrasound was delivered at 7.3 MHz with a low output (-20 dB) for aiming and with the maximal output (0 dB) for exposure. Pulmonary capillary hemorrhage was quantified by an assessment of comet tail artifacts in the LUS images and by measurement of PCH areas on the surface of fresh lung samples. RESULTS: Tests without shock or catheterization surgery gave results for PCH similar to those of previous studies using different methods. Exposure before hemorrhagic shock gave a mean PCH area ± SE of 24.8 ± 9.2 mm2 on the ultrasound scan plane, whereas exposure after shock gave 0 PCH (P < .001; n = 7). CONCLUSIONS: The presence of hemorrhagic shock significantly reduces the occurrence of LUS-induced PCH.

Usefulness of dynamic computed tomography for diagnosing and evaluating uterine artery pseudoaneurysms in women with late post-partum hemorrhage not complicated by retained products of conception.

AIM: We examined whether critical conditions, which were defined as having hemoglobin (Hb) less than 7.0 g/dL, shock index ≥1.0, or need for transfusion, were associated with the presence of extravasation (EV) on dynamic computed tomography (CT) in women with late post-partum hemorrhage (PPH). METHODS: Forty post-partum women with late PPH without evident retained products of conception performed dynamic CT. Two radiologists retrospectively evaluated dynamic CT, and determined the presence or absence of EV and a sac-like structure within the uterine cavity with enhancement. RESULTS: Ultrasound images were available in 34/40 patients. Color Doppler flow in uterine cavity was evaluated in 33/34 (97%), and all women showed abnormal flow. Of 40 patients, dynamic CT revealed EV in 8 (20%), and a sac-like structure in 30 (75%). Thus, we diagnosed these 38 (95%) as having uterine artery pseudoaneurysm (UAP). Uterine artery embolization was performed in 36/38 diagnosed as having UAP, and in 2/2 patients with an unknown cause of hemorrhage. The incidence rates of critical conditions were significantly increased in PPH women with than without EV on dynamic CT: Hb <7.0 g/dL (62.5 vs 0%, [P < 0.001]), shock index ≥1.0 (50 vs 9.4% [P = 0.020]), and need for transfusion (37.5 vs 0% [P = 0.006]). Abnormal color Doppler flows were observed in all patients with either EV and sac on dynamic CT. CONCLUSION: Dynamic CT was useful for diagnosing UAP, and for evaluating critical conditions, in women with late PPH not complicated by retained products of conception.

The resuscitative endovascular balloon occlusion of aorta (REBOA) device-what radiologists need to know.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a novel device approved by the Food and Drug administration (FDA) in 2017 as an alternative to resuscitative emergent thoracotomy (RET). Due to advancements in placement of REBOA, including newly validated placement using anatomic landmarks, REBOA is now widely used by interventional radiologists and emergency physicians in acute subdiaphragmatic hemorrhage. Increased use of REBOA necessitates that radiologists are familiar with verification of proper REBOA placement to minimize complications. This review describes the REBOA device, indications, placement, and complications, summarizing the current available literature.

A rat model of acute kidney injury through systemic hypoperfusion evaluated by micro-US, color and PW-Doppler.

AIM: To create an animal model of acute renal ischemia induced by systemic hypoperfusion, controllable and reproducible to study, in real time, hemorrhagic shock changes with micro-imaging. ANIMALS AND METHODS: Hemorrhagic shock was induced in rats activating a syringe pump setup to remove 1 mL/min of blood, through the femoral artery catheter. The withdrawal was continued until the mean arterial pressure (MAP) dropped to 25-30 mmHg. For the next 60 min, the MAP was maintained at a constant pressure value, by automatic pump infusion and withdrawal. Micro-ultrasound imaging was performed using the Vevo 2100 system with the MS250 transducer (13-24 MHz). Renal size, morphology and echogenicity were evaluated in B-mode. Renal blood flow was evaluated using color and PW-Doppler. RESULTS: After 1 h of ischemia, B-mode images documented slight changes in kidney echogenicity. Color and PW-Doppler analysis showed a reduction in renal blood flow in kidneys during the hypoperfusion with a progressive and significant change from baseline values of resistive index (RI). At the histological evaluation, 60 min of hypoperfusion resulted in ischemic changes in the kidneys. CONCLUSIONS: The results of this experimental study encourage the use of the described model to study acute renal ischemia trough severe hypoperfusion. The histological data confirmed that the model was able to produce injury in renal parenchyma. It can be used to assess acute ischemic damage not only in the kidney but also in other organs by using all available dedicated small animals imaging techniques.

Vasculotide, an Angiopoietin-1 Mimetic, Restores Microcirculatory Perfusion and Microvascular Leakage and Decreases Fluid Resuscitation Requirements in Hemorrhagic Shock.

BACKGROUND: Microcirculatory dysfunction is associated with multiple organ failure and unfavorable patient outcome. We investigated whether therapeutically targeting the endothelial angiopoietin/Tie2 system preserves microvascular integrity during hemorrhagic shock. METHODS: Rats were treated with the angiopoietin-1 mimetic vasculotide and subjected to hemorrhagic shock and fluid resuscitation. Microcirculatory perfusion and leakage were assessed with intravital microscopy (n = 7 per group) and Evans blue dye extravasation (n = 8 per group), respectively. The angiopoietin/Tie2 system was studied at protein and RNA level in plasma, kidneys, and lungs. RESULTS: Hemorrhagic shock significantly reduced continuously perfused capillaries (7 ± 2 vs. 11 ± 2) and increased nonperfused vessels (9 ± 3 vs. 5 ± 2) during hemorrhagic shock, which could not be restored by fluid resuscitation. Hemorrhagic shock increased circulating angiopoietin-2 and soluble Tie2 significantly, which associated with microcirculatory perfusion disturbances. Hemorrhagic shock significantly decreased Tie2 gene expression in kidneys and lungs and induced microvascular leakage in kidneys (19.7 ± 11.3 vs. 5.2 ± 3.0 µg/g) and lungs (16.1 ± 7.0 vs. 8.6 ± 2.7 µg/g). Vasculotide had no effect on hemodynamics and microcirculatory perfusion during hemorrhagic shock but restored microcirculatory perfusion during fluid resuscitation. Interestingly, vasculotide attenuated microvascular leakage in lungs (10.1 ± 3.3 µg/g) and significantly reduced the required amount of volume supplementation (1.3 ± 1.4 vs. 2.8 ± 1.5 ml). Furthermore, vasculotide posttreatment was also able to restore microcirculatory perfusion during fluid resuscitation. CONCLUSIONS: Targeting Tie2 restored microvascular leakage and microcirculatory perfusion and reduced fluid resuscitation requirements in an experimental model of hemorrhagic shock. Therefore, the angiopoietin/Tie2 system seems to be a promising target in restoring microvascular integrity and may reduce organ failure during hemorrhagic shock.

Cerebral Blood Flow in Polytrauma: Transcranial Doppler Analysis in a Nonhuman Primate Shock Model.

BACKGROUND: In combat-related trauma, resuscitation goals are to attenuate tissue hypoxia and maintain circulation. During hemorrhagic shock, compensatory and autoregulatory mechanisms are activated to preserve cerebral blood flow. Transcranial Doppler (TCD) ultrasonography may be an ideal noninvasive modality to monitor cerebral hemodynamics. Using a nonhuman primate (NHP) model, we attempted to characterize cerebral hemodynamics during polytraumatic hemorrhagic shock using TCD ultrasonography. MATERIALS AND METHODS: The ophthalmic artery was insonated at multiple time points during varying stages of shock. Hemorrhage was controlled and pressure targeted to 20 mmHg to initiate and maintain the shock period. Mean flow velocity (MFV), peak systolic velocity (PSV), end diastolic velocity (EDV), pulsatility index (PI), and resistance index (RI) were recorded. Results represent mean ± standard deviation; statistical significance is P < 0.05; n = 12. RESULTS: Compared to baseline, MFV, PSV, EDV, and RI show significant changes after 60 min of hemorrhagic shock, (9.81 ± 3.60 cm/s; P < 0.01), (21.15 ± 8.59 cm/s; P < 0.01), (5.15 ± 0.21 cm/s; P < 0.01), (0.70 ± 0.11; P < 0.05), respectively. PI did not change during hemorrhagic shock. At end of prehospital care (T30), cerebral flow recovers for MFV, PSV, and RI while EDV remained decreased at T30 (6.15 ± 1.13 cm/s; P < 0.01) and 1 h of simulated transport (T90) (5.87 ± 0.62 cm/s; P < 0.01). Changes in PI at T30 and T90 were not significant. MFV diminished (16.45 ± 3.85 cm/s; P < 0.05) at T90. CONCLUSIONS: This study establishes baseline and hemorrhagic shock values for NHP cerebral blood flow velocities and cerebrovascular indices. TCD ultrasonography may represent an important area of research for targeted resuscitation investigations using a hemorrhagic shock model in NHPs.

Estimation of Stroke Volume and Stroke Volume Changes by Electrical Impedance Tomography.

BACKGROUND: Electrical impedance tomography (EIT) is a noninvasive imaging method that identifies changes in air and blood volume based on thoracic impedance changes. Recently, there has been growing interest in EIT to measure stroke volume (SV). The objectives of this study are as follows: (1) to evaluate the ability of systolic impedance variations (ΔZsys) to track changes in SV in relation to a baseline condition; (2) to assess the relationship of ΔZsys and SV in experimental subjects; and (3) to identify the influence of body dimensions on the relationship between ΔZsys and SV. METHODS: Twelve Agroceres pigs were instrumented with transpulmonary thermodilution catheter and EIT and were mechanically ventilated in a random order using different settings of tidal volume (VT) and positive end-expiratory pressure (PEEP): VT 10 mL·kg and PEEP 10 cm H2O, VT 10 mL·kg and PEEP 5 cm H2O, VT 6 mL·kg and PEEP 10 cm H2O, and VT 6 mL·kg and PEEP 5 cm H2O. After baseline data collection, subjects were submitted to hemorrhagic shock and successive fluid challenges. RESULTS: A total of 204 paired measurements of SV and ΔZsys were obtained. The 4-quadrant plot showed acceptable trending ability with a concordance rate of 91.2%. Changes in ΔZsys after fluid challenges presented an area under the curve of 0.83 (95% confidence interval, 0.74-0.92) to evaluate SV changes. Conversely, the linear association between ΔZsys and SV was poor, with R from linear mixed model of 0.35. Adding information on body dimensions improved the linear association between ΔZsys and SV up to R from linear mixed model of 0.85. CONCLUSIONS: EIT showed good trending ability and is a promising hemodynamic monitoring tool. Measurements of absolute SV require that body dimensions be taken into account.

Damage Control and the Open Abdomen: Challenges for the Nonsurgical Intensivist.

BACKGROUND: As strategies in acute care surgery focus on damage control to restore physiology, intensivists spanning all disciplines care for an increasing number of patients requiring massive transfusion, temporary abdominal closures, and their sequelae. OBJECTIVE: To equip the nonsurgical intensivist with evidence-based management principles for patients with an open abdomen after damage control surgery. DATA SOURCE: Search of PubMed database and manual review of bibliographies from selected articles. DATA SYNTHESIS AND CONCLUSIONS: Temporary abdominal closure improves outcomes in patients with abdominal compartment syndrome, hemorrhagic shock, and intra-abdominal sepsis but creates new challenges with electrolyte derangement, hypovolemia, malnutrition, enteric fistulas, and loss of abdominal wall domain. Intensive care of such patients mandates attention to resuscitation, sepsis control, and expedient abdominal closure.

Pan-Cardiac Cycle Fixed Mitral Valve Opening in an LVAD Patient Presenting with Hemorrhagic Shock.

We present the case of a patient with a HeartMate II left ventricular assist device (LVAD) who underwent an elective cholecystectomy and abruptly decompensated on postoperative day 9. We highlight the uncommon echocardiogram finding of mitral valve leaflets fixed widely open throughout the cardiac cycle during an LVAD suction event. Bedside echocardiographic confirmation of a suction event enabled the rapid diagnosis and intervention for hemorrhagic shock before blood tests and radiographic results were available. Acoustic image quality can be limited in LVAD patients, and awareness of this uncommon finding may increase specificity for the echocardiographic diagnosis of LVAD suction events.

A new model for the study of secondary intra-abdominal hypertension in rats.

BACKGROUND: To build a new and appropriate model of secondary intra-abdominal hypertension (IAH) in rats. METHODS: A total of 32 female Sprague-Dawley rats were randomized into four groups. Group I: the rats were hemorrhaged to a mean arterial pressure (MAP) of 40 mm Hg for 1 h and portal hypertension was induced by partial ligation of the portal vein 1 h later; Group II: after inducing portal hypertension, hemorrhagic shock of MAP of 40 mm Hg was induced and maintained for 1 h; Group III: after inducing portal hypertension, hemorrhagic shock of MAP of 40 mm Hg was induced and maintained for 2 h; Group IV: after inducing portal hypertension, hemorrhagic shock of MAP of 40 mm Hg was induced and maintained for 2 h, and a specially designed abdominal restraint device was used. After these procedures, respectively, the collected blood was reinfused and lactated Ringer solution was continuously infused until the secondary IAH model was established. RESULTS: No models were built in Groups I, II, and III. One rat died in Group IV after portal vein ligation, and all the remaining rats successfully developed IAH; the success rate was 87.5%. During the resuscitation period, the average time was 5.26 ± 0.59 h and the average total infusion volume was 665.5 ± 86.04 mL/kg. CONCLUSION: A rat model of secondary IAH was successfully established by resuscitation after a combination of inducing portal hypertension, hemorrhaging to a MAP of 40 mm Hg for 2 h, and using an abdominal restraint device. All these criteria mimic key etiological factors for the development of secondary IAH.

[Giant subcutaneous hematoma with hemorrhagic shock induced by goserelin acetate injection for prostate cancer : report of a case].

A 87-year-old man was diagnosed with prostate cancer (cT2aN0M0 Gleason score 4＋4 with initial prostate specific antigen of 23.4 ng/ml). Prostate cancer was treated with combined androgen blockade (goserelin acetate plus flutamide). He was administered goserelin acetate depot injection without any complications as an outpatient. However, 5 hours after he left the hospital, he came back to the hospital, complaining of lower abdominal pain. Abdominal computed tomography revealed a giant subcutaneous hematoma in the lower abdomen. Hemoglobin was 6.9 g/dl and blood pressure was lower than 80 mmHg. He was admitted and given a blood transfusion. Because of pre-disseminated intravascular coagulation score 6, it was hard to antagonize warfarin by Vitamin K (he had taken warfarin because of atrial fibrillation). Arteriography was performed and injury to a branch of the lower epigastric artery was found. Transcatheter arterial embolization was performed at the same time. Injecting goserelin acetate may cause severe arterial injury.

[Case of small bowel angioectasia in which the resection site was angiographically detected using intraoperative dye infusion].

A 37-year-old Japanese man undergoing treatment for dilated cardiomyopathy was presented with weakness and melena. He had conjunctival pallor and difficulty in standing;his blood pressure was 81/62 mmHg. Abdominal computed tomography revealed contrast dye leakage into the small intestine. He was diagnosed with hemorrhagic shock secondary to intestinal bleeding;we administered large volumes of intravenous fluid along with performing a blood transfusion. We then performed angiography to determine the site of bleeding angioectasia and placed a catheter into the affected artery. We identified the resection site using an intraoperative dye infusion via the catheter, and successfully performed small bowel resection. He was subsequently discharged without complications.

Evaluation of hemorrhagic shock and fluid resuscitation in pigs using handless Doppler carotid artery ultrasound.

OBJECTIVE: This study aimed to utilize a hemorrhagic shock pig model to compare two hemodynamic monitoring methods, pulse index continuous cardiac output (PiCCO) and spectral carotid artery Doppler ultrasound (CDU). Additionally, we sought to explore the feasibility of employing CDU as a non-invasive hemodynamic monitoring tool in the context of hemorrhagic shock and fluid resuscitation. DESIGN: Animal experiments. SETTING AND SUBJECTS: Female pigs were selected, and hemorrhagic shock was induced by rapid bleeding through an arterial sheath. INTERVENTIONS: Hemodynamic monitoring was conducted using both PiCCO and CDU during episodes of hemorrhagic shock and fluid resuscitation. MEASUREMENTS AND MAIN RESULTS: Among the 10 female pigs studied, CDU measurements revealed a significant decrease in carotid velocity time integral (cVTI) compared to baseline values under shock conditions. During the resuscitation phase, after the mean arterial pressure (MAP) returned to its baseline level, there was no significant difference between cVTI and baseline values. A similar trend was observed for carotid peak velocity (cPV). The corrected flow time (FTc) exhibited a significant difference only at the time of shock compared to baseline values. In comparison to PiCCO, there was a significant correlation between cVTI and MAP (r = 0.616, P < 0.001), stroke volume (SV) (r = 0.821, P < 0.001), and cardiac index (CI) (r = 0.698, P < 0.001). The carotid Doppler shock index (cDSI) displayed negative correlations with MAP (r = - 0.593, P < 0.001), SV (r = - 0.761, P < 0.001), and CI (r = - 0.548, P < 0.001), while showing a positive correlation with the shock index (SI) (r = 0.647, P < 0.001). CONCLUSIONS: Compared to PiCCO, CDU monitoring can reliably reflect the volume status of hemorrhagic shock and fluid resuscitation. CDU offers the advantages of being non-invasive, providing real-time data, and being operationally straightforward. These characteristics make it a valuable tool for assessing and managing hemorrhagic shock, especially in resource-limited settings.

ASSESSMENT OF ABNORMAL SKELETAL MUSCLE PERFUSION BY CONTRAST-ENHANCED ULTRASOUND WITH PARAMETRIC IMAGING IN RATS AFTER SEVERE INJURY, HEMORRHAGIC SHOCK, AND WHOLE BLOOD RESUSCITATION.

ABSTRACT: Background: After severe injury, optical measures of microvascular blood flow (MBF) decrease and do not normalize with resuscitation to normal blood pressure. These changes are associated with organ dysfunction, coagulopathy, and death. However, the pathophysiology is not well understood. Several possible pathways could also contribute to the development of trauma-induced coagulopathy (TIC). A small-animal model of trauma-related MBF derangement that persists after resuscitation and includes TIC would facilitate further study. Parametric contrast-enhanced ultrasound (CEUS) is particularly advantageous in this setting, because it noninvasively assesses MBF in large, deep vascular beds. We sought to develop such a model, measuring MBF with CEUS. Methods: Sixteen male Sprague-Dawley rats were anesthetized, ventilated, and cannulated. Rats were subjected to either no injury (sham group) or a standardized polytrauma and pressure-targeted arterial catheter hemorrhage with subsequent whole blood resuscitation (trauma group). At prespecified time points, CEUS measurements of uninjured quadriceps muscle, viscoelastic blood clot strength, and complete blood counts were taken. Results: After resuscitation, blood pressure normalized, but MBF decreased and remained low for the rest of the protocol. This was primarily driven by a decrease in blood volume with a relative sparing of blood velocity. Viscoelastic blood clot strength and platelet count also decreased and remained low throughout the protocol. Conclusion: We present a rat model of MBF derangement in uninjured skeletal muscle and coagulopathy after polytrauma that persists after resuscitation with whole blood to normal macrohemodynamics. Parametric CEUS analysis shows that this change is primarily due to microvascular obstruction. This platform can be used to develop a deeper understanding of this important process.

Depletion of myocardial glucose is observed during endotoxemic but not hemorrhagic shock in a porcine model.

INTRODUCTION: Metabolic dysfunction is one of the hallmarks of sepsis yet little is known about local changes in key organs such as the heart. The aim of this study was to compare myocardial metabolic changes by direct measurements of substrates, such as glucose, lactate and pyruvate, using microdialysis (MD) in in-vivo porcine endotoxemic and hemorrhagic shock. To assess whether these changes were specific to the heart, we simultaneously investigated substrate levels in skeletal muscle. METHODS: Twenty-six female pigs were randomized to three groups: control (C) n = 8, endotoxemic shock (E) n = 9 and hemorrhagic shock (H) n = 9. Interstitial myocardial pyruvate, lactate and glucose were measured using MD. Skeletal muscle MD was also performed in all three groups. RESULTS: Marked decreases in myocardial glucose were observed in the E group but not in the H group compared to controls (mean difference (CI) in mmol/L: C versus E -1.5(-2.2 to -0.8), P <0.001; H versus E -1.1(-1.8 to -0.4), P = 0.004; C versus H -0.4(-1.1 to 0.3), P = 0.282). Up to four-fold increases in myocardial pyruvate and three-fold increases in lactate were seen in both shock groups with no differences between the two types of shock. There was no evidence of myocardial anaerobic metabolism, with normal lactate:pyruvate (L:P) ratios seen in all animals regardless of the type of shock. CONCLUSIONS: Endotoxemia, but not hemorrhage, induces a rapid decrease of myocardial glucose levels. Despite the decrease in glucose, myocardial lactate and pyruvate concentrations were elevated and not different than in hemorrhagic shock. In skeletal muscle, substrate patterns during endotoxemic shock mimicked those seen in myocardium. During hemorrhagic shock the skeletal muscle response was characterized by a lack of increase in pyruvate and higher L:P ratios. Hence, metabolic patterns in the myocardium during endotoxemic shock are different than those seen during hemorrhagic shock. Skeletal muscle and myocardium displayed similar substrate patterns during endotoxemic shock but differed during hemorrhagic shock.

Ultrasound Localization of Resuscitative Endovascular Balloon Occlusion of the Aorta in a Human Cadaver Model.

OBJECTIVE: Resuscitative endovascular balloon occlusion of the aorta (REBOA) is a method of gaining proximal control of noncompressible torso hemorrhage (NCTH). Catheter placement is traditionally confirmed with fluoroscopy, but few studies have evaluated whether ultrasound (US) can be used. METHODS: Using a pressurized human cadaver model, a certified REBOA placer was shown one of four randomized cards that instructed them to place the REBOA either correctly or incorrectly in Zone 1 (the distal thoracic aorta extending from the celiac artery to the left subclavian artery) or Zone 3 (in the distal abdominal aorta, from the aortic bifurcation to the lowest renal artery). Once the REBOA was placed, 10 US-trained locators were asked to confirm balloon placement via US. The participants were given 3 minutes to determine whether the catheter had been correctly placed, repeating this 20 times on two cadavers. RESULTS: Overall, US exhibited an average sensitivity of 83%, specificity of 76%, and accuracy of 80%. For Zone 1, US showed a sensitivity of 78% and specificity of 83%, and for Zone 3, a sensitivity of 88% and specificity of 76%. In addition, US exhibited a likelihood positive ratio (LR+) of 3.73 and a likelihood negative ratio (LR-) of 0.22 for either position, with similar numbers for Zone 1 (+4.57, -0.26) and Zone 3 (+3.16, -0.16). CONCLUSION: Ultrasound could prove to be a useful tool for confirming placement of a REBOA catheter, especially in austere environments.

Ultrasound assessment is useful for evaluating balloon volume of resuscitative endovascular balloon occlusion of the aorta.

BACKGROUND: Endovascular balloon occlusion of the aorta (EBOA) increases proximal arterial pressure but may also induce life-threatening ischemic complications. Although partial REBOA (P-REBOA) mitigates distal ischemia, it requires invasive monitoring of femoral artery pressure for titration. In this study, we aimed to titrate P-REBOA to prevent high-degree P-REBOA using ultrasound assessment of femoral arterial flow. METHODS: Proximal (carotid) and distal (femoral) arterial pressures were recorded, and perfusion velocity of distal arterial pressures was measured by pulse wave Doppler. Systolic and diastolic peak velocities were measured among all ten pigs. Total REBOA was defined as a cessation of distal pulse pressure, and maximum balloon volume was documented. The balloon volume (BV) was titrated at 20% increments of maximum capacity to adjust the degree of P-REBOA. The distal/proximal arterial pressure gradient and the perfusion velocity of distal arterial pressures were recorded. RESULTS: Proximal blood pressure increased with increasing BV. Distal pressure decreased with increasing BV, and distal pressure sharply decreased by > 80% of BV. Both systolic and diastolic velocities of the distal arterial pressure decreased with increasing BV. Diastolic velocity could not be recorded when the BV of REBOA was > 80%. CONCLUSION: The diastolic peak velocity in the femoral artery disappeared when %BV was > 80%. Evaluation of the femoral artery pressure by pulse wave Doppler may predict the degree of P-REBOA without invasive arterial monitoring.

Retroperitoneal hemorrhage after percutaneous coronary intervention in the current practice era: clinical outcomes and prognostic value of abdominal/pelvic computed tomography.

BACKGROUND: Retroperitoneal hemorrhage (RPH) is a serious but infrequent complication of percutaneous coronary intervention (PCI). This study aimed to describe the clinical outcomes of patients who developed RPH following PCI in the current practice era, with particular focus on treatment strategies and the related prognostic value of abdominal/pelvic computed tomography (CT). METHODS: Among 20,904 patients undergoing PCI, we identified 93 RPH (0.45%) confirmed by CT or by unequivocal surgical findings. We identified three groups with RPH for comparison: patients who developed refractory shock (systolic blood pressure <80 mm Hg for ≥30 min despite fluids and vasopressors, n = 16 [17.2%]); patients with transient hypotension (<30 min, n = 34 [36.6%]); and patients without hypotension (n = 43 [46.2%]). The primary endpoint was a composite of in-hospital mortality, myocardial infarction, and cerebral vascular accident (CVA). RESULTS: Baseline clinical, angiographic, and procedural characteristics were similar among the three groups. Patients who developed refractory shock had significantly more bleeding quantified by abdominal/pelvic CT (P < 0.001), had a higher rate and amount of red blood cell transfusion (P < 0.001), and were managed invasively more frequently (68.7%) than the rest of the population. The primary endpoint trended higher in patients presenting with refractory shock; however, this difference was not statistically significant. The volume of bleeding quantified by CT and the timing of imaging diagnosis did not correlate with the primary endpoint. Red blood cell transfusion, but not clopidogrel discontinuation, was associated with the primary endpoint. CONCLUSIONS: RPH remains as a serious complication of PCI and is associated with high rates of mortality and morbidity independently of the therapeutic strategy. In patients who were hemodynamically stable, RPH volume as quantified by non-contrast abdominal/pelvic CT did not contribute to prognosis.

Organ perfusion during partial REBOA in haemorrhagic shock: dynamic 4D-CT analyses in swine.

Resuscitative endovascular balloon occlusion of the aorta (REBOA) increases proximal blood pressure while inducing distal ischemia of visceral organs. The evaluation of distal ischemia severity during REBOA is a prerequisite for safe resuscitation of haemorrhagic shock patients with REBOA. We evaluated changes in blood flow and organ perfusion due to the degree of occlusion using dynamic 4D-computed tomography (CT). We compared the results with those of a previous study on euvolemic status. Delayed enhancement of the inferior vena cava (IVC) without retrograde flow was observed in the 4D-volume rendering images in the high-degree occlusion. The time-density curve (TDC) of the liver parenchyma (liver perfusion) and superior mesenteric vein (SMV) demonstrated a decreased peak density and a delayed peak in high-degree occlusion. The change rate of the area under the TDC of the liver and SMV decreased linearly as the degree of occlusion increased (PV, Y = -1.071*X + 106.8, r2 = 0.972, P = 0.0003; liver, Y = -1.050*X + 101.8, r2 = 0.933, P = 0.0017; SMV, Y = -0.985*X + 100.3, r2 = 0.952, P = 0.0009). Dynamic 4D-CT revealed less severe IVC congestion during P-REBOA in haemorrhagic shock than in euvolemia. Analyses of TDC of the liver and SMV revealed a linear change in organ perfusion, regardless of intravascular volume.

Can blood loss be assessed by echocardiography? An experimental study on a controlled hemorrhagic shock model in piglets.

BACKGROUND: Assessment of the volemic loss is a major challenge during the management of hemorrhagic shock. Echocardiography is an increasingly used noninvasive tool for hemodynamic assessment. In mechanically ventilated patients, some studies suggest that respiratory variations of mean subaortic time-velocity integral (∆VTI) would be predictive of fluid filling response. An experimental model of controlled hemorrhagic shock provides a precise approach to study correlation between blood volume and cardiac ultrasonographic parameters. OBJECTIVES: The main objective was to analyze the ∆VTI changes during hemorrhage in an anesthetized-piglet model of controlled hemorrhagic shock. The secondary objective was to evaluate ∆VTI during the resuscitation process after hemorrhage and other echocardiographic parameters changes during the whole protocol. METHODS: Twenty-four anesthetized and ventilated piglets were bled until mean arterial pressure reached 40 mm Hg. Controlled hemorrhage was maintained for 30 minutes before randomizing the piglets to two resuscitation groups: fluid filling group resuscitated with saline solution and noradrenaline group resuscitated with saline solution and noradrenaline. Echocardiography and hemodynamic measures, including pulsed pressure variations (PPV), were performed at different stages of the protocol. RESULTS: The correlation coefficient between ΔVTI and PPV with the volume of bleeding during the hemorrhagic phase were respectively 0.24 (95% confidence interval, 0.08-0.39; p < 0.01) and 0.57 (95% CI, 0.44-0.67; p < 0.01). Two parameters had a moderate correlation coefficient with hemorrhage volume (over 0.5): mean subaortic time-velocity index (VTI) and mitral annulus diastolic tissular velocity (E'). CONCLUSION: In this hemorrhagic shock model, ΔVTI had a low correlation with the volume of bleeding, but VTI and E' had a correlation with blood volume comparable to that of PPV.