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Background: Excessive intraoperative bleeding remains a challenge in limb surgeries. The exsanguination tourniquet ring has emerged as a potential solution for effective exsanguination and hemostasis. This study aims to evaluate its efficacy and safety compared to the conventional exsanguination and hemostasis approach (pneumatic tourniquet combined with Esmarch bandage). Methods: This randomized controlled trial evaluates the exsanguination tourniquet ring's effectiveness and safety versus the conventional approach in 220 participants undergoing various limb surgeries. Allocation included experimental and control groups, assesses through efficacy (including intraoperative and total blood loss, hemoglobin levels, and exsanguination and hemostasis effectiveness) and safety (adverse event occurrence) indicators. Results: The experimental group (n = 110) utilizes the exsanguination tourniquet ring, while the control group (n = 110) employs the conventional approach. As for intraoperative blood loss, the experimental group is non-inferior to the control group (p-value < 0.001). While no significant difference is found in total blood loss (for the full analysis set, p-value = 0.442; for the per protocol set, p-value = 0.976) and differences in postoperative and preoperative hemoglobin levels (for the full analysis set, p-value = 0.502; for the per protocol set, p-value = 0.928). Regarding exsanguination and hemostasis effectiveness, the full analysis set reveals significantly superior ratings in the experimental group compared to the control group (p-value = 0.002 < 0.05), while the per protocol set analysis indicates no significant difference between the groups (p-value = 0.504). As for safety indicators, adverse events related to the device are minimal in two groups, with only one severe event unrelated to the device. Conclusions: The exsanguination tourniquet ring is an effective and safe device for intraoperative blood loss control in various limb surgeries. Trial registration: Comparison of Exsanguination and Hemostasis Devices for Limb Surgery A Prospective Multicenter Randomized Controlled Study, ChiCTR2300077998, 11/27/2023. [ABSTRACT FROM AUTHOR]

Abstract Background Excessive intraoperative bleeding remains a challenge in limb surgeries. The exsanguination tourniquet ring has emerged as a potential solution for effective exsanguination and hemostasis. This study aims to evaluate its efficacy and safety compared to the conventional exsanguination and hemostasis approach (pneumatic tourniquet combined with Esmarch bandage). Methods This randomized controlled trial evaluates the exsanguination tourniquet ring’s effectiveness and safety versus the conventional approach in 220 participants undergoing various limb surgeries. Allocation included experimental and control groups, assesses through efficacy (including intraoperative and total blood loss, hemoglobin levels, and exsanguination and hemostasis effectiveness) and safety (adverse event occurrence) indicators. Results The experimental group (n = 110) utilizes the exsanguination tourniquet ring, while the control group (n = 110) employs the conventional approach. As for intraoperative blood loss, the experimental group is non-inferior to the control group (p-value

Severe external hemorrhage is a significant reason for morbidity and mortality in adults; thus, the swift and correct application of a tourniquet by laypersons can be lifesaving. We conducted this randomized-controlled cross-over study to investigate the use of a novel tourniquet. Participants were recruited at the Heidelberg University Hospital. Eligible participants were ≥ 18 years old with a medical background but without prior experience in applying a tourniquet. Participants were 1:1 randomized to the intervention group (PAX tourniquet) or the control group (SAM or CAT tourniquet). In the control group, participants underwent another randomization to either the SAM or CAT tourniquet without a predefined allocation ratio. Hyperspectral measurements were undertaken (i) before ligation, (ii) 30 s after ligation, and (iii) 30 s after the reopening of the tourniquet. The primary outcome was time until ligation before crossover between the respective groups. The analysis of secondary endpoints included all attempts to assess a possible learning effect, intraoperator variability, and hyperspectral measurements. Participants were crossed to the other study group after a brief wash-out phase. In total, 50 participants were recruited, resulting in 100 attempts. A success rate of 98% was observed across the study population. Time until ligation was 49 s and 56 s (p = 0.572) in the intervention and control group, respectively. However, there was a significant difference between the PAX and SAM (54 vs 75 s; p = 0.037) and the SAM and CAT tourniquet (75 vs. 47 s; p = 0.015). Further, we observed a significant learning effect in participants allocated to the control group first, with a median reduction of 9 s in the time until ligation. Hyperspectral measurements showed a significant decrease in perfusion and tissue oxygenation after ligation. Further, a significant increase in perfusion and tissue oxygenation was found after reopening the tourniquet compared to the baseline measurement. The novel PAX tourniquet can be applied quickly and effectively by medical personnel without prior experience in applying a tourniquet. [ABSTRACT FROM AUTHOR]

We present a case of a complex suicide of a 66-year-old man with a history of several psychiatric disorders. He attempted to commit suicide by inflicting cut wounds on his forearms, wrists, and neck but afterwards changed the method of suicide by using an electric power drill. After several unsuccessful attempts to drill a hole in either his head, thorax, or abdomen, he managed to perforate the common carotid artery on the right side of his neck and subsequently died from exsanguination. [ABSTRACT FROM AUTHOR]

Background: A distally based sural flap is a workhorse flap used to reconstruct the distal lower leg and foot. It developed a bad reputation due to venous congestion, leading to flap failure. Herein, we present a new modification in the form of proximal catheterization and distal ligation of the short saphenous vein to relieve flap congestion. Methods: Twenty patients underwent reconstruction with distally based sural artery flaps for defects around the ankle, distal leg, and foot from June 2019 to March 2021. Distal ligation with proximal catheterization of the short saphenous vein was performed to reduce the risk of venous congestion. Results: Early flap congestion was observed in five flaps (25%). The venous congestion was relieved by draining congested blood through the catheter. The total amount of blood removed was around 80–100 mL in the first 2 days postoperatively. The flaps healed uneventfully as two flaps with distal 2-cm necrosis healed with dressing. Conclusions: Distal ligation of the short saphenous vein may prevent venous overloading from the foot and reduce sural flap venous congestion. Proximal catheterization of the vein to relieve flap congestion is an effective flap safety tool. Level of evidence: Level V, Risk/Prognostic. [ABSTRACT FROM AUTHOR]

SUMMARY: With over 9 billion broilers processed each year in the United States, blood is a significant by-product of poultry processing. An adequate bleed-out during slaughter with subsequent blood collection results in blood being redirected from the wastewater stream to rendering, less wastewater treatment needed at the processing plant, and more saleable by-product. There is relatively little current research into the effect of stunning method on blood loss and blood loss rate, particularly on today's high breast meat-yield broilers. This study aimed to determine the percent of blood loss and rate of blood loss for 3 stunning methods (alternating current [AC] electrocution, pulsed direct current [DC] electrical stun, and controlled atmosphere stun/kill [CASK]) across the 2 most commonly used neck cut methods (1-sided neck cut [1S] and 2-sided neck cut [2S]). Four trials of 120 birds each from separate flocks of male broilers at 62 d, 45 d, 43 d, and 43 d of age were stunned and then exsanguinated via 1S or 2S. Postneck cut, carcass weights were recorded in 15 s intervals for 180 s. In general, DC stunning resulted in significantly greater blood loss and rates of blood loss than either AC or CASK, whereas exsanguination method and treatment interactions had limited impact. Upon evisceration, a substantial proportion of residual blood in AC and CASK broiler carcasses was found to be in the viscera. These results highlight the need to closely revaluate bleed-out and blood collection processes when changing stunning method in broilers.

SUMMARY: Optimal bleed-out of commercial broilers in a poultry processing facility results in increased product quality, improved wastewater quality, and allows processors an opportunity to recover additional profits through rendering. Little data exist on how exsanguination method affects the blood loss of modern heavy, high breast meat-yield broilers during bleed-out. This study measured the impact of a 1-sided neck cut (1S), 2-sided neck cut (2S), decapitation at the base of head (DH), and decapitation at base of neck (DN) on birds 51 d (n = 88), 45 d (n = 96), 44 d (n = 88), and 36 d of age (n = 80). Regardless of treatment, 73 to 77% of all blood lost occurred during the first 30 s with only 5 to 7% of total blood loss happening after 90 s of bleed-out time. 1S resulted in a lower initial rate of blood loss than DH or DN in 3 out of 4 trials. From ∼30 to 90 s of bleed-out time, DH and DN tended to lose blood at a slower rate than 1S. On average, 1S resulted in the highest percent of blood loss in all flocks at 180 s of bleed-out time, and in 3 out of 4 trials at 90 s of bleed-out (exception being 51 d). In 3 out of 4 trials, DN resulted in the lowest average percent of blood loss at both 180 s and 90 s of bleed-out (exception being 44 d). Results validate the current industry standard of 90 s of bleed-out time regardless of exsanguination method.

In reaction to publishing the article by P.T. Skoczykłoda (Zoophilologica nr 2 (10)/2022) who uses religious sources to demonstrate that Jewish ritual slaughter or shechita does not harm animals more than the standard slaughter, and portrays this stance as being compatible with science, the shechita is here compared to the standard slaughter in the light of current knowledge. All credible results of physiological experiments and systematic studies of the real proces in the slughter-houses leave no doubt that the correct standard slaughter starting with stunning causes much less suffering than any, even perfect cut without stunning which leaves an animal conscious with excruiciating pain until the death by exsanguina-tion. Several independent quantitative studies of the latter demonstrated, that stunning preceding the cut does not affect either the rate or the final effect of exsanguination, which runs contrary to the religious tales, and calls into question the very religious sense of ritual slaughter. Systematic observations in slaughterhouses show that both standard slaughter and shechita are prone to malfunction that affects substantial numbers of animals and cause a great amount of additional pain except that faulty stunning shots should and usually are corrected by a second shot whereas in shechita animals are left to die of exsanguination whatever the cause of their prolonged agony (usually 20-80 seconds but sometimes much longer). In addition, the neck cut of a fully conscious animal necessaitates complete restraint - whereas in a modern slaughterhouse the cow is compressed in a slaughter box, in the traditional shechita the cow had the muzzle shackled to the ground while being suspended and hoisted by one hind leg, all of which is a torture made of pain and panic. This infamous, broadly used shackle-and-hoist technique, only recently banned in the USA and Isreal under the public pressure, contradicts the claim that shechita is meant to alleviate animal suffering. [ABSTRACT FROM AUTHOR]

Trauma remains one of the leading causes of death in adults despite the implementation of preventive measures and innovations in trauma systems. The etiology of coagulopathy in trauma patients is multifactorial and related to the kind of injury and nature of resuscitation. Trauma-induced coagulopathy (TIC) is a biochemical response involving dysregulated coagulation, altered fibrinolysis, systemic endothelial dysfunction, platelet dysfunction, and inflammatory responses due to trauma. The aim of this review is to report the pathophysiology, early diagnosis and treatment of TIC. A literature search was performed using different databases to identify relevant studies in indexed scientific journals. We reviewed the main pathophysiological mechanisms involved in the early development of TIC. Diagnostic methods have also been reported which allow early targeted therapy with pharmaceutical hemostatic agents such as TEG-based goal-directed resuscitation and fibrinolysis management. TIC is a result of a complex interaction between different pathophysiological processes. New evidence in the field of trauma immunology can, in part, help explain the intricacy of the processes that occur after trauma. However, although our knowledge of TIC has grown, improving outcomes for trauma patients, many questions still need to be answered by ongoing studies. [ABSTRACT FROM AUTHOR]

The management of a rare midclavicular crossbow bolt injury to the subclavian artery is discussed. Important concepts include the initial clinical diagnosis, operative planning, the surgical approach to the retro-clavicular great vessels, the technical aspects of repair, and postoperative course. A discussion of the reasoning behind an operative vs. endovascular approach is also discussed. [ABSTRACT FROM AUTHOR]

Hemorrhagic shock (HS) management is based on a timely, rapid, definitive source control of bleeding/s and on blood loss replacement. Stopping the hemorrhage from progressing from any named and visible vessel is the main stem fundamental praxis of efficacy and effectiveness and an essential, obligatory, life-saving step. Blood loss replacement serves the purpose of preventing ischemia/reperfusion toxemia and optimizing tissue oxygenation and microcirculation dynamics. The "physiological classification of HS" dictates the timely management and suits the 'titrated hypotensive resuscitation' tactics and the 'damage control surgery' strategy. In any hypotensive but not yet critical shock, the body's response to a fluid load test determines the cut-off point between compensation and progression between the time for adopting conservative treatment and preparing for surgery or rushing to the theater for rapid bleeding source control. Up to 20% of the total blood volume is given to refill the unstressed venous return volume. In any critical level of shock where, ab initio, the patient manifests signs indicating critical physiology and impending cardiac arrest or cardiovascular accident, the balance between the life-saving reflexes stretched to the maximum and the insufficient distal perfusion (blood, oxygen, and substrates) remains in a liable and delicate equilibrium, susceptible to any minimal change or interfering variable. In a cardiac arrest by exsanguination, the core of the physiological issue remains the rapid restoration of a sufficient venous return, allowing the heart to pump it back into systemic circulation either by open massage via sternotomy or anterolateral thoracotomy or spontaneously after aorta clamping in the chest or in the abdomen at the epigastrium under extracorporeal resuscitation and induced hypothermia. This is the only way to prevent ischemic damage to the brain and the heart. This is accomplishable rapidly and efficiently only by a direct approach, which is a crush laparotomy if the bleeding is coming from an abdominal +/− lower limb site or rapid sternotomy/anterolateral thoracotomy if the bleeding is coming from a chest +/− upper limbs site. Without first stopping the bleeding and refilling the heart, any further exercise is doomed to failure. Direct source control via laparotomy/thoracotomy, with the concomitant or soon following venous refilling, are the two essential, initial life-saving steps. [ABSTRACT FROM AUTHOR]

Trauma remains a leading cause of death worldwide, and most early preventable deaths in both the civilian and military settings are due to uncontrolled hemorrhage, despite paradigm advances in modern trauma care. Combined tissue injury and shock result in hemostatic failure, which has been identified as a multidimensional molecular, physiologic and clinical disorder termed trauma-induced coagulopathy (TIC). Understanding the biology of TIC is of utmost importance, as it is often responsible for uncontrolled bleeding, organ failure, thromboembolic complications, and death. Investigations have shown that TIC is characterized by multiple phenotypes of impaired hemostasis due to altered biology in clot formation and breakdown. These coagulopathies are attributable to tissue injury and shock, and encompass underlying endothelial, immune and inflammatory perturbations. Despite the recognition and identification of multiple mechanisms and mediators of TIC, and the development of targeted treatments, the mortality rates and associated morbidities due to hemorrhage after injury remain high. The purpose of this review is to examine the past and present understanding of the multiple distinct but highly integrated pathways implicated in TIC, in order to highlight the current knowledge gaps and future needs in this evolving field, with the aim of reducing morbidity and mortality after injury.

BackgroundHistorically, hemorrhage has been attributed as the leading cause (40%) of early death. However, a rigorous, real-time classification of the cause of death (COD) has not been performed. This study sought to prospectively adjudicate and classify COD to determine the epidemiology of trauma mortality.MethodsEighteen trauma centers prospectively enrolled all adult trauma patients at the time of death during December 2015 to August 2017. Immediately following death, attending providers adjudicated the primary and contributing secondary COD using standardized definitions. Data were confirmed by autopsies, if performed.ResultsOne thousand five hundred thirty-six patients were enrolled with a median age of 55 years (interquartile range, 32-75 years), 74.5% were male. Penetrating mechanism (n = 412) patients were younger (32 vs. 64, p < 0.0001) and more likely to be male (86.7% vs. 69.9%, p < 0.0001). Falls were the most common mechanism of injury (26.6%), with gunshot wounds second (24.3%). The most common overall primary COD was traumatic brain injury (TBI) (45%), followed by exsanguination (23%). Traumatic brain injury was nonsurvivable in 82.2% of cases. Blunt patients were more likely to have TBI (47.8% vs. 37.4%, p < 0.0001) and penetrating patients exsanguination (51.7% vs. 12.5%, p < 0.0001) as the primary COD. Exsanguination was the predominant prehospital (44.7%) and early COD (39.1%) with TBI as the most common later. Penetrating mechanism patients died earlier with 80.1% on day 0 (vs. 38.5%, p < 0.0001). Most deaths were deemed disease-related (69.3%), rather than by limitation of further aggressive care (30.7%). Hemorrhage was a contributing cause to 38.8% of deaths that occurred due to withdrawal of care.ConclusionExsanguination remains the predominant early primary COD with TBI accounting for most deaths at later time points. Timing and primary COD vary significantly by mechanism. Contemporaneous adjudication of COD is essential to elucidate the true understanding of patient outcome, center performance, and future research.Level of evidenceEpidemiologic, level II.

Abstract The present study was designed to compare the effects of lidocaine and ropivacaine in intravenous regional anaesthesia (IVRA) in dogs. Twelve adult male dogs were used. Under isoflurane anaesthesia, exsanguination was performed in the target forelimb. Then, a blood pressure cuff was encircled around the limb proximal to the elbow joint with a pressure of approximately 150 mmHg above the mean arterial blood pressure. The animals then received one of the two treatments of lidocaine (3 mg/kg) or ropivacaine (1.5 mg/kg) with a final volume of 0.6 mL/kg into the cephalic vein. After 60 min, the anaesthesia was disrupted and the tourniquet was removed using intermittent opening (30 s) and closing (5 min) manner for three times. The results revealed that at 20 and 30 min after the initiation of IVRA, the dogs in ROP showed higher analgesia than LID. A leakage under the tourniquet during IVRA was detected. Tremor and hypersalivation were observed after tourniquet removal in some dogs. It was concluded that ropivacaine might provide a higher quality of anaesthesia than lidocaine in IVRA in dogs. The development of local anaesthetic toxicity is a major concern and should be considered at the time of tourniquet removal.

Background: Hemorrhagic shock is a clinically challenging disease process with high mortality. When conventional blood products are unable to be administered, oxygen‐carrying blood alternatives are sometimes utilized. The international experience with this scenario is limited. We aim to add to this body of literature. Study Design and Methods: This is a case report of the administration of bovine hemoglobin‐based oxygen‐carrying red blood cell (RBC) substitute HBOC‐201 (HemoPure®) to a patient with post‐partum bleeding and hemorrhagic shock because the patient declined RBC transfusion. HBOC‐201 was administered with consent under a one‐time Emergency Investigational New Drug (eIND) approval from the Food and Drug Administration with appropriate notification of the Institutional Review Board. Results: The patient was successfully resuscitated with HBOC‐201 from hemorrhagic shock. She was weaned off of vasopressor support and extubated with the recovery of her baseline mental status within 4 h. However, approximately 36 h after this, the patient developed multi‐organ system dysfunction, volume overload, right heart failure and ultimately expired early on post‐partum day 4. Discussion: Resuscitation from hemorrhagic shock with HBOC‐201 as an RBC alternative is feasible, but significant challenges remain with the management of sequelae resulting from prolonged low‐flow, ischemic states as well as the significant colloid pressure and volume overload experienced after massive transfusion with an acellular colloid oxygen carrier. [ABSTRACT FROM AUTHOR]

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Trauma remains one of the leading causes of death in adults despite the implementation of preventive measures and innovations in trauma systems. The etiology of coagulopathy in trauma patients is multifactorial and related to the kind of injury and nature of resuscitation. Trauma-induced coagulopathy (TIC) is a biochemical response involving dysregulated coagulation, altered fibrinolysis, systemic endothelial dysfunction, platelet dysfunction, and inflammatory responses due to trauma. The aim of this review is to report the pathophysiology, early diagnosis and treatment of TIC. A literature search was performed using different databases to identify relevant studies in indexed scientific journals. We reviewed the main pathophysiological mechanisms involved in the early development of TIC. Diagnostic methods have also been reported which allow early targeted therapy with pharmaceutical hemostatic agents such as TEG-based goal-directed resuscitation and fibrinolysis management. TIC is a result of a complex interaction between different pathophysiological processes. New evidence in the field of trauma immunology can, in part, help explain the intricacy of the processes that occur after trauma. However, although our knowledge of TIC has grown, improving outcomes for trauma patients, many questions still need to be answered by ongoing studies.

Aim : To describe and compare the aortic-right atrial pressure (AoP-RAP) gradients and mean coronary perfusion pressures (CPPs) generated during open chest selective aortic arch perfusion (OCSAAP) with those generated during open cardiac massage (OCM) in hypovolemic swine. Methods : Ten male Hanford swine utilized in a prior poly-trauma study were included in the study. Animals were rendered hypovolemic via a 30% volume bleed. Upon confirmation of death, animals underwent immediate clamshell thoracotomy and aortic cross-clamping followed by 5 min of OCM. A catheter suitable for OCSAAP was then inserted into the aorta and animals underwent 1 min of OCSAAP at a rate of 10 mL/kg/min. Aortic and right atrial pressures were recorded continuously using solid-state blood pressure catheters. Representative 10-s intervals from each resuscitation method were extracted. Hemodynamic parameters including AoP-RAP gradients and CPPs were calculated and compared. Results : At baseline, time from death to intervention was significantly shorter for OCM. However, mean CPPs and AoP-RAP gradients were significantly higher in animals undergoing OCSAAP. 98% of OCSAAP segments had a mean CPP > 15, compared to 35% of OCM intervals. While OCM had a significant negative correlation between time to intervention and maximum CPP, this correlation was not significant for OCSAAP. Conclusion : OCSAAP generates favorable and potentially time-resistant pressure gradients when compared to those generated by OCM. Further investigation of the technique of OCSAAP is warranted, as it may have potential utility as a therapy during resuscitative thoracotomy (RT). [ABSTRACT FROM AUTHOR]

Background : Penetrating injuries to sacrum are rare; only a few reports have been published in literature. We hereby report the first case of low velocity penetrating trauma leading to coccygeal fracture dislocation and exsanguination, without any major abdominal/vascular injury. Case Report : The patient underwent wound packing bedside and hemostatic resuscitation. Wound packing was successful in achieving hemostasis. He stabilized after 1.5 L of fluids, massive hemorrhage protocol institution (12-unit blood components), and vasopressor support. The presentation is unique and not reported in literature published so far. Conclusion : This report is a pertinent example of lifesaving potential of effective wound packing, which is often under-utilized. Possibility of associated neurological injury and residual foreign bodies is there in such cases. They should be duly assessed after stabilizing life-threatening injuries. [ABSTRACT FROM AUTHOR]

Background: During hemorrhage and resuscitation, clinical and laboratory monitoring is useful to guide further management. However, acute changes in the biochemistry due to blood loss and subsequent crystalloid fluid resuscitation have not been fully studied. Materials and methods: Twelve anesthetized, juvenile pigs were used. Atraumatic exsanguination, corresponding to a total blood loss of 40%, was performed through a catheter and completed 2 h after initiation of the experiment. Arterial samples were analyzed by point-of-care testing and venous samples were analyzed. Oxygen delivery was calculated. Results: Shortly after 40% hemorrhage and concomitant fluid supplementation, there were significant reductions in arterial hemoglobin and hematocrit (approximately 25%, respectively). Oxygen delivery was less than half of the baseline value. Lactate in arterial blood was more than doubled after 40% exsanguination. On average, no other clinically significant changes in any of the analytes were observed, but interindividual dispersion was pronounced. Conclusions: Acute exsanguination was associated with decreased hemoglobin and hematocrit levels and increased lactate levels but limited effects on the other biomarkers that were studied. Increased levels of biomarkers in severely bleeding patients could indicate tissue damage and the source should be further investigated.

Background: Cases of external hemorrhage are difficult to recognize on postmortem computed tomography (PMCT). Purpose: To investigate the effects of blood loss on CT attenuation of the spleen, liver, kidneys, and lungs on PMCT and to assess the relationship between blood loss and organ weight. Methods: A total of 125 cases with blood loss were sex- and age-matched to 125 control cases without blood loss. Individual organ attenuation was measured on transverse CT images. Organ weights of the liver, spleen, kidneys, and lung were extracted from the autopsy protocols. Results: Organ weight was significantly lower in cases with blood loss (lung 30%, spleen 28%, kidneys 14%, liver 18%) than in controls. CT attenuation of the lungs was significantly lower (30%) in cases with blood loss than in controls. CT attenuation of the spleen and kidneys did not significantly differ between cases and controls. CT attenuation of the liver was significantly higher (25%) in cases with blood loss than in controls. Conclusion: Blood loss decreases organ weight and CT attenuation of the lungs but appears to have no significant effect on CT attenuation of the spleen and kidneys. The increased liver attenuation in cases with blood loss compared to controls was an unexpected finding and remains challenging to explain. One probable interpretation refers to different levels of hepatic glycogen; however, further work is warranted to substantiate this hypothesis. [ABSTRACT FROM AUTHOR]

Objective: To describe resuscitation patterns of critically bleeding dogs, including those receiving massive transfusion (MT).Design: Retrospective study from three universities (2007–2013).Animals: Critically bleeding dogs, defined as dogs who received ≥ 25 ml/kg of blood products for treatment of hemorrhagic shock caused by blood loss.Measurements and Main Results: Sixty-nine dogs were included. Sources of critical bleeding were trauma (26.1%), intra/perioperative surgical period (26.1%), miscellaneous (24.6%), and spontaneous hemoabdomen (23.1%). Median (range) age was 7 years (0.5–18). Median body weight was 20 kg (2.6–57). Median pre-transfusion hematocrit, total protein, systolic blood pressure, and lactate were 25% (10–63), 4.1 g/dl (2–7.1), 80 mm Hg (20–181), and 6.4 mmol/L (1.1–18.2), respectively. Median blood product volume administered was 44 ml/kg (25–137.4). Median plasma to red blood cell ratio was 0.8 (0–4), and median non-blood product resuscitation fluid to blood product ratio was 0.5 (0–3.6). MT was given to 47.8% of dogs. Survival rate was 40.6%. The estimated odds of survival were higher by a factor of 1.8 (95% CI: 1.174, 3.094) for a dog with 1 g/dl higher total protein above reference interval and were lower by a factor of 0.6 (95% CI: 0.340, 0.915) per 100% prolongation of partial thromboplastin time above the reference interval. No predictors of MT were identified.Conclusions: Critical bleeding in dogs was associated with a wide range of resuscitation patterns and carries a guarded to poor prognosis.

The present study was designed to compare the effects of lidocaine and ropivacaine in intravenous regional anaesthesia (IVRA) in dogs. Twelve adult male dogs were used. Under isoflurane anaesthesia, exsanguination was performed in the target forelimb. Then, a blood pressure cuff was encircled around the limb proximal to the elbow joint with a pressure of approximately 150 mmHg above the mean arterial blood pressure. The animals then received one of the two treatments of lidocaine (3 mg/kg) or ropivacaine (1.5 mg/kg) with a final volume of 0.6 mL/kg into the cephalic vein. After 60 min, the anaesthesia was disrupted and the tourniquet was removed using intermittent opening (30 s) and closing (5 min) manner for three times. The results revealed that at 20 and 30 min after the initiation of IVRA, the dogs in ROP showed higher analgesia than LID. A leakage under the tourniquet during IVRA was detected. Tremor and hypersalivation were observed after tourniquet removal in some dogs. It was concluded that ropivacaine might provide a higher quality of anaesthesia than lidocaine in IVRA in dogs. The development of local anaesthetic toxicity is a major concern and should be considered at the time of tourniquet removal. [ABSTRACT FROM AUTHOR]

Hemorrhagic shock (HS) management is based on a timely, rapid, definitive source control of bleeding/s and on blood loss replacement. Stopping the hemorrhage from progressing from any named and visible vessel is the main stem fundamental praxis of efficacy and effectiveness and an essential, obligatory, life-saving step. Blood loss replacement serves the purpose of preventing ischemia/reperfusion toxemia and optimizing tissue oxygenation and microcirculation dynamics. The “physiological classification of HS” dictates the timely management and suits the ‘titrated hypotensive resuscitation’ tactics and the ‘damage control surgery’ strategy. In any hypotensive but not yet critical shock, the body’s response to a fluid load test determines the cut-off point between compensation and progression between the time for adopting conservative treatment and preparing for surgery or rushing to the theater for rapid bleeding source control. Up to 20% of the total blood volume is given to refill the unstressed venous return volume. In any critical level of shock where, ab initio, the patient manifests signs indicating critical physiology and impending cardiac arrest or cardiovascular accident, the balance between the life-saving reflexes stretched to the maximum and the insufficient distal perfusion (blood, oxygen, and substrates) remains in a liable and delicate equilibrium, susceptible to any minimal change or interfering variable. In a cardiac arrest by exsanguination, the core of the physiological issue remains the rapid restoration of a sufficient venous return, allowing the heart to pump it back into systemic circulation either by open massage via sternotomy or anterolateral thoracotomy or spontaneously after aorta clamping in the chest or in the abdomen at the epigastrium under extracorporeal resuscitation and induced hypothermia. This is the only way to prevent ischemic damage to the brain and the heart. This is accomplishable rapidly and efficiently only by a direct approach, which is a crush laparotomy if the bleeding is coming from an abdominal +/− lower limb site or rapid sternotomy/anterolateral thoracotomy if the bleeding is coming from a chest +/− upper limbs site. Without first stopping the bleeding and refilling the heart, any further exercise is doomed to failure. Direct source control via laparotomy/thoracotomy, with the concomitant or soon following venous refilling, are the two essential, initial life-saving steps.

Background: At the 2023 ATLS symposium, the priority of circulation was emphasized through the "x-airway-breathing-circulation (ABC)" sequence, where "x" stands for exsanguinating hemorrhage control. With growing evidence from military and civilian studies supporting an x-ABC approach to trauma care, a prehospital advanced resuscitative care (ARC) bundle emphasizing early transfusion was developed in our emergency medical services (EMS) system. We hypothesized that prioritization of prehospital x-ABC through ARC would reduce in-hospital mortality., Study Design: This was a single-year prospective analysis of patients with severe hemorrhage. These patients were combined with our institution's historic controls before prehospital blood implementation. Included were patients with systolic blood pressure (SBP) less than 90 mmHg. Excluded were patients with penetrating head trauma or prehospital cardiac arrest. Two-to-one propensity matching for x-ABC to ABC groups was conducted, and the primary outcome, in-hospital mortality, was compared between groups., Results: A total of 93 patients (x-ABC = 62, ABC = 31) met the inclusion criteria. There was no difference in patient age, sex, initial SBP, initial Glasgow Coma Score, and initial shock index between groups. When compared with the ABC group, x-ABC patients had significant improvement in vitals at emergency department admission. Overall mortality was lower in the x-ABC group (13% vs 47%, p < 0.001). Multivariable regression revealed that prehospital circulation-first prioritization was independently associated with decreased in-hospital mortality (odds ratio 0.15, 95% CI 0.04 to 0.54, p = 0.004)., Conclusions: This is the first analysis to demonstrate a prehospital survival benefit of x-ABC in this subset of patient with severe injury and hemorrhagic shock. Standardization of prehospital x-ABC management in this patient population warrants special consideration., (Copyright © 2024 by the American College of Surgeons. Published by Wolters Kluwer Health, Inc. All rights reserved.)

Objective: Early assessment of the clinical status of trauma patients is crucial for guiding the treatment strategy, and it requires a rapid and systematic approach. The aim of this report is to critically review the assessment parameters currently used in the prehospital setting to quantify blood loss in trauma. Data Sources: Studies regarding hemorrhagic shock in trauma were pooled from PubMed, EMBASE, and Cochrane databases using key words such as "hemorrhagic shock," "vital signs evaluation," "trauma," "blood loss," and "emergency medical service," alone or combined. Study Selection: Articles published since 2009 in English and Italian were considered eligible if containing data on assessment parameters in blood loss in adults. Data Extraction: Sixteen articles matching the inclusion criteria were considered in our study. Data Synthesis: Current prehospital assessment measures lack precise correlation with blood loss. Conclusions: Traditional assessment parameters such as heart rate, systolic blood pressure, shock index, and Glasgow Coma Scale score often lag in providing accurate blood loss assessment. The current literature supports the need for a noninvasive, continuously monitored assessment parameter to identify early shock in the prehospital setting. JTRAN Journal of Trauma Nursing 1078-7496 Wolters Kluwer Health, Inc. 10.1097/JTN.0000000000000608 00011 3 CONCISE REVIEW Prehospital Hemorrhage Assessment Criteria: A Concise Review Di Carlo Sara MD, PhD saradicarlo81@gmail.com Cavallaro Giuseppe MD, PhD giuseppe.cavallaro@uniroma1.it Palomeque Kenia MS kenia-kp-95@live.it Cardi Maurizio MD, PhD maurizio.cardi@uniroma1.it Sica Giuseppe MD, PhD sigisica@gmail.com Rossi Piero MD, PhD piero.rossi@uniroma2.it Sibio Simone MD, PhD simone.sibio@uniroma1.it Department of Surgery, Tor Vergata University of Rome, Viale Oxford, Rome, Italy (Drs Di Carlo, Sica, and Rossi); and Department of Surgery "Pietro Valdoni," University "Sapienza" of Rome, Viale del Policlinico, Rome, Italy (Drs Cavallaro, Cardi, and Sibio and Ms Palomeque). Correspondence: Simone Sibio, MD, PhD, Department of Surgery, "Viale del Policlinico", University "Sapienza" of Rome, "Pietro Valdoni," Via Lancisi 2—00161 Rome, Italy (simone.sibio@uniroma1.it). Data and materials are available upon request. The authors declare no conflicts of interest. September/October 2021 28 5 332 338 © 2021 Society of Trauma Nurses 2021 Objective: Early assessment of the clinical status of trauma patients is crucial for guiding the treatment strategy, and it requires a rapid and systematic approach. The aim of this report is to critically review the assessment parameters currently used in the prehospital setting to quantify blood loss in trauma. Data Sources: Studies regarding hemorrhagic shock in trauma were pooled from PubMed, EMBASE, and Cochrane databases using key words such as "hemorrhagic shock," "vital signs evaluation," "trauma," "blood loss," and "emergency medical service," alone or combined. Study Selection: Articles published since 2009 in English and Italian were considered eligible if containing data on assessment parameters in blood loss in adults. Data Extraction: Sixteen articles matching the inclusion criteria were considered in our study. Data Synthesis: Current prehospital assessment measures lack precise correlation with blood loss. Conclusions: Traditional assessment parameters such as heart rate, systolic blood pressure, shock index, and Glasgow Coma Scale score often lag in providing accurate blood loss assessment. The current literature supports the need for a noninvasive, continuously monitored assessment parameter to identify early shock in the prehospital setting. Blood loss Emergency Exsanguination Hemorrhagic shock Prehospital care Quantitative measures Trauma Worldwide, trauma is the leading cause of death and disability in patients younger than 40 years, and it accounts for approximately 8% of all deaths, causing an enormous socioeconomic impact with regard to the costs of treatment and rehabilitation (World Health Organization, 2021). Hemorrhage is among the main causes of death in trauma, which can be exacerbated by inaccurate recognition or delayed treatment (Dunham, Sartorius, Laing, Bruce, & Clarke, 2017; Lui et al., 2018). Hemorrhagic shock pathophysiology and compensatory mechanisms contribute to the masking of signs of clinical deterioration. Thus, knowledge of underlying pathophysiology assists the clinician's interpretation of assessment parameters. PATHOPHYSIOLOGY OF HEMORRHAGE: Massive brisk intravascular volume loss leads to hemodynamic instability, decreased oxygen delivery, reduced tissue perfusion, cellular hypoxia, organ damage, and death. A significant loss in circulating blood volume can depress cardiac output hence reducing organ perfusion pressure. A decrease in arterial pressure stimulates sympathetic nerve activity. Catecholamines, antidiuretic hormone, and atrial natriuretic receptors induce vasoconstriction of arterioles and muscular arteries, increasing vascular resistance leading to a compensatory elevation in arterial pressure. With the depletion of intravascular volume and the reduced oxygen availability in the tissues, mitochondria are no longer able to sustain aerobic metabolism for energy production and switch to anaerobic metabolism. In aerobic conditions, systemic oxygen utilization is proportional to the metabolic rate, and it varies according to the body's needs. During the shock, prostaglandins, adenosine, and nitric oxide tend to lower vascular resistance leading to hypoxic redistribution of blood flow to all organs. Under these conditions, a failure of the protonic pumps and the alteration of ion transport lead to a loss of the membrane integrity, depletion of cellular energy, acidosis, and loss of adenine nucleotides from the cell. This mechanism should maintain the perfusion pressure by increasing cardiac output. As a result of hypovolemia and tissue hypoxia, the ventilation increases (tachypnea) to compensate for the metabolic acidosis caused by carbon dioxide production. The decrease of blood flow to the renal and splanchnic vasculature contributes to a further drop of the systolic blood pressure (SBP) (Cannon, 2018; Convertino, Wirt, Glenn, & Lein, 2016). Prehospital assessment of hemorrhage is important because it is potentially the most critical time to detect and intervene with damage control measures. The first approach to the trauma patient occurs with assessment of the mechanism of injury to identify potential patterns of injury (Cardi et al., 2019; Frank et al., 2010). Time is crucial in trauma. Prehospital care is prioritized with lifesaving scene management and prompt transport to the most appropriate facility, often characterized as occurring within the "golden hour" (Wyen et al., 2013). Blood loss estimation is notoriously challenging and consistently reported as unreliable (Ashburn, Harrison, Ham, & Strote, 2012). Hemorrhage classification systems help clinicians rapidly and systematically focus assessment of the bleeding patient. The most commonly taught hemorrhagic shock classification is from Advanced Trauma Life Support (ATLS); see Table 1 (American College of Surgeons Committee on Trauma, 2021). However, evidence challenges the accuracy of the ATLS shock classification (Guly et al., 2011; Mutschler, Nienaber, Brockamp, et al., 2013; Mutschler, Nienaber, et al., 2014; Mutschler, Paffrath, et al., 2014; Reisner et al., 2018). The ATLS classification is based on average or standardized responses of static variables maintained by the body's mechanisms to compensate for blood loss. However, not all patients compensate equally. What is needed is an individualized and continuous assessment of the patient's progression toward shock that considers the patient's total degree of compensation to identify those patients deteriorating into early shock. Prehospital estimation of blood loss is crucial, yet tools to predict blood loss and need for transfusion are often time-consuming and impractical in the prehospital setting (Olaussen, Blackburn, Mitra, & Fitzgerald, 2014; Van Sickle et al., 2013). Prompt shock recognition is essential to apply damage control resuscitation to reverse the conditions that exacerbate hemorrhage (Tonglet, Minon, Seidel, Poplavsky, & Vergnion, 2014). TABLE 1 Vital Signs Classification of Hemorrhagic Shock Based on Advanced Trauma Life Support: Shock Class Group 1 2 3 4 HR (BPM) <100 100–119 120–139 >140 SBP (mm Hg) >110 100–109 90–99 <90 GCS 15 15 12–14 <12 Note. BPM = beats per minute; GCS = Glasgow Coma Scale; HR = heart rate; mmHg = millimeters of mercury; SBP = systolic blood pressure. OBJECTIVE: The aim of this study is to critically review the assessment parameters currently used in the prehospital setting to quantify blood loss in trauma. METHODS: A systematic search was performed of the PubMed, EMBASE, and Cochrane databases using the key words "hemorrhagic shock," "vital signs scale evaluation," "trauma," "blood loss," and "emergency medical service," alone or embedded. All articles published since 2009 matching with the search terms were analyzed. Only those studies concerning the adult trauma population and written in English or Italian were considered. References of the included studies were analyzed to find additional relevant articles. Articles were considered eligible if containing data on assessment parameters and blood loss in trauma patients undergoing hypovolemic shock. Titles and abstracts underwent a double-blinded evaluation to select articles for full-text reading. A senior researcher acted as supervisor in case of discordance. A final selection of articles was provided and underwent full text reading. RESULTS: A total of 16 articles were included in the study, which identified five assessment measures used for prehospital estimation of blood loss. The measures include heart rate (HR), SBP, Shock Index (SI), Glasgow Coma Scale (GCS) score, and visual estimation of blood loss (see Table 2). TABLE 2 Analysis of Available Measures: Authors Scale Parameters Author Opinion Reisner et al. (2018) ATLS HR, SBP, BL Changes appear to be subtle Guly et al. (2011)Mutschler et al. (2013) SI (HR/SBP) 4 classes: SI ≥ 1 good parameter to predict ↑mortality and ↑ bt Pacagnella et al. (2013) I: ≤0.6 Van Sickle et al. (2013) II: ≥0.6 to ≤1 Pandit et al. (2014) III: ≥1 to ≤1.4 Olaussen et al. (2014) IV: ≥1.4 Merlin et al. (2009) MAR method Clenched fist = 20-ml blood Improves accuracy and precision Note. ATLS = Advanced Trauma Life Support; BL = blood loss; bt = blood unit; HR = heart rate transfusions; SBP = systolic blood pressure; SI = Shock Index. Patient Characteristics: Other factors can also influence the accuracy of data provided by assessment measures. Among them, the most important in altering clinical values are those depending on patient characteristics and treatment, such as the following: Age: Patients older than 55 years with normal vital signs cannot rule out impending shock. An HR greater than 100 and SBP of 100–110 may represent hypoperfusion (Heffernan et al., 2010), and the SI can increase from 0.79 to 0.81 (Zarzaur, Croce, Fischer, Magnotti, & Fabian, 2008) Comorbidities: Neurological, cardiovascular, autoimmune Medications: β-blockers or neurological drugs can underestimate the shock Lifestyle: Fit and active patients with physiological bradycardia achieve HR compensation values of up to 80–90 bpm Pregnancy: May lead to an underestimation of the bleeding due to the physiological changes Fluids: Prehospital administration of 1L of fluids shifts the SI cutoff values to 1.0 and greater (1.1 [SD = 0.6] vs. 0.7 [SD = 0.2], p >.001; Mitra, Fitzgerald, & Chan, 2013). Assessment Parameters: HR and SBP: The inverse relationship of HR to SBP is commonly assumed to occur in hemorrhage and commonly taught to providers to assess, yet it does not consistently occur among bleeding patients (Pacagnella et al., 2013). Using standardized vital sign norms does not distinguish those patients who can compensate well versus those who cannot, leading to delayed identification of shock progression. Mounting evidence challenge the dogma that vital signs changes can identify early blood loss. Mizushima, Ueno, Watanabe, Ishikawa, and Matsuoka (2011) retrospectively analyzed a large database of trauma patients with base deficit and lactate levels indicating hemorrhage; a normal HR was a predictor of poor prognosis. Heart rate is nonspecific to blood loss and influenced by other factors such as age, pain, temperature, and medications, and thus cannot be considered a reliable parameter. Indeed, bradycardia or normal HR is reported to be more common in hemorrhage than expected. Ley, Salim, Kohanzadeh, Mirocha, and Margulies (2009) found the incidence of relative bradycardia in 44% of all hypotensive trauma patients on a large data set of more than 130,000 patients. They also found that bradycardia is an indicator of higher mortality. Similar results were reported by Riordan, Norris, Jenkins, and Morris (2009) in a study of 2,178 trauma patients admitted to the intensive care unit, in which reduced HR was associated with worsening prognosis and higher mortality, especially in patients with isolated head injury or penetrating trauma. Guly et al. (2011), in a study of blunt and penetrating trauma, demonstrated an average HR and blood pressure (in patients with blood loss of >40% of the volume) lower than the values reported in the ATLS classification for the same hypovolemia (Class 4). Moreover, a varied correlation between vital signs and actual blood loss was highlighted by Reisner et al. (2018). Their retrospective comparative analysis studied HR changes in adult trauma with hemorrhage during either prehospital or emergency department care. Hemorrhage patients were divided into two groups, those with a normal HR and those with tachycardia. They demonstrated that some trauma patients with hemorrhage are continuously tachycardic whereas others have a normal HR. For both cohorts, hypotension developed within 30 min without any consistent increase in HR. Tachycardia was not specific for hemorrhage. Shock Index: Shock index, defined as the HR divided by SBP with values of 1 or more considered abnormal, is another parameter used to assess blood loss. Shock index is gaining favor as a predictor for transfusion or prognostic factor in major trauma (Mutschler, Nienaber, Brockamp, et al., 2013; Pandit et al., 2014). Olaussen et al. (2014) demonstrated the SI's effectiveness in identifying severe bleeding in the prehospital setting. However, this observation was not confirmed by Van Sickle et al. (2013), who found that SI indicated hypovolemia only in the advanced stages of reduced central blood volume; moreover, they established that this index was not able to estimate the blood volume loss or to establish the patient's residual compensation capacity. The main limit of this study was the small sample size of 15 patients. Glasgow Coma Scale: According to the ATLS classification, GCS, together with SBP and HR, is considered one of the parameters evaluated in the prehospital setting and on admission to rule out hemorrhagic shock. The descriptors slightly anxious and mildly anxious were considered a GCS score of 15, whereas anxious or confused was considered a GCS score of 12–14 and confused or lethargic as GCS score of less than 12. Changes in the GCS are considered reliable indicators of hemorrhagic shock for some authors (Vishwanathan, Chhajwani, Gupta, & Vaishya, 2020). Some reports found a correlation between hypotension and GCS reduction for patients with injury severity score of more than 15 (Guly et al., 2011), whereas other studies with larger data sets find a lack of a clear correlation between GCS and changes in SBP and HR as well as the onset and progression of hypotension (Mutschler, Nienaber, Munzberg, et al., 2013). Furthermore, prehospital GCS could be influenced by prehospital intubation, whose rates vary across providers. Visual Estimation of Blood Loss: Analysis of large data sets suggests a correlation between the volume of red blood cell loss and the blood products needed to reestablish hemodynamic balance. High severity bleeding (>15% of circulating blood volume) in trauma leads to an average of 6–10 units of blood transfused per patient in 24 hr, especially for those who experience hypotension and tachycardia (Reisner et al., 2018; Weeber, Hunter, Van Hoving, & Lategan, 2018). Even from these studies, inaccurate evaluation of the blood loss emerges; for values less than 300 ml, there was a tendency to overestimate the quantity, whereas for volumes between 400 ml and 1,500 ml, there was an underestimation (Patton, Funk, Mcerlean, & Bartfield, 2001). This study found that emergency medical service personnel were unable or strongly inaccurate in estimating blood loss. Similar results were reported by Frank et al. (2010), who used a prospective blinded, observational design and asked the participants to visually estimate the amount of blood loss in six simulated trauma scenarios. Both paramedics and emergency physicians overestimated the amount of blood loss when the assessment parameters showed instability (low blood pressure, high HR). Small volumes were overestimated for both stable and unstable patients, whereas higher volumes tended to be underestimated. The accuracy of blood loss evaluation was not influenced by profession (emergency physician or paramedic), gender, or experience level. Ashburn et al. (2012) demonstrated that such estimates could be misleading if used in clinical decision making. Williams and Boyle (2007) described the inaccuracy of blood loss estimation given by undergraduate paramedic students for both absorbent and impermeable surfaces. Finally, Phillips, Friberg, Lantz Cronqvist, Jonson, and Prytz (2020) investigated the ability of laypeople to assess blood loss and also found overestimation of small volumes (from 50 to 200 ml) and underestimation of large volumes (from 400 to 1,900 ml). Moreover, the underestimation was more common for female victims than for male victims. One novel study sought to identify a comparable estimate of blood loss using the size of a clenched fist (Merlin, Alter, Raffel, & Pryor, 2009). Called the MAR method, a clenched fist was found to approximate roughly 20 ml of blood loss. Merlin et al. (2009) performed an unblinded crossover trial of 74 health care professionals' estimation of blood loss in two scenarios (75 ml and 750 ml). A comparison before and after a 1-min education session on the MAR method demonstrated significantly improved blood loss estimation. DISCUSSION: Humans compensate for blood loss through a cascade of physiologic responses, contributing to unrecognized hemorrhagic shock. Our review finds a lack of reliable assessment measures to identify early blood loss in the prehospital setting. Although advances in trauma technology, practice, and guidelines continuously update, the prehospital ability to assess hemorrhage has not changed for decades. Accurate estimation of blood loss in trauma is paramount, yet neither medical personnel nor paramedics are instructed how to estimate blood volume loss and have no specific measure to assess it. The cornerstone of hemorrhagic trauma management is the reestablishment of hemodynamic stability by controlling the source of bleeding and reintegrating the volume loss with balanced transfusions, all of which begin with prehospital recognition of blood loss. Future Directions: Emerging research explores new technology that may help with prehospital hemorrhage recognition. Ultrasound: The role of ultrasound-focused assessment with sonography in trauma is emerging as a tool for the prehospital environment and holds promise (Kalkwarf, Goodman, Press, Wade, & Cotton, 2021; Pietersen et al., 2021). Its role is operator-dependent, and it has some limitations, such as difficulties in exploring some deep regions and poor detection of some organ injuries depending on the patients' habitus (Miele et al., 2016). Therefore, a negative examination does not rule out injuries and must be verified by a computed tomographic scan (Stengel et al., 2018). However, it has several advantages, such as portability, speed, and the lack of ionizing radiation exposure. End-tidal Carbon Dioxide: End-tidal carbon dioxide (ETCO2) is the measurement of alveolar carbon dioxide concentration at end-expiration. It is measured noninvasively either in the ventilator circuit of intubated patients or with specialized nasal cannulas in nonintubated patients. End-tidal carbon dioxide is widely available across emergency medical services agencies and holds promise as prehospital levels have been shown to correlate with mortality and the need for massive transfusion or early death (Campion et al., 2020). Compensatory Reserve Measurement: There is ongoing military research to develop wearable sensors to measure a patient's compensatory reserve defined as a composite or sum total of the patient's individual compensatory responses (tachycardia, vasoconstriction, breathing) to hemorrhage using real-time measurement of arterial waveforms. The measurement of a patient's compensatory reserve is more sensitive and specific in monitoring physiological status than other measures, including HR variability and HR complexity, and hold promise as a future shock measure as technology advances (Convertino et al., 2016; Convertino et al., 2020, Schlotman et al., 2020). Limitations: Our review has some limitations. First is the limited number of articles that address the correlation between assessment parameters and blood loss or the classification or quantification of blood loss in a standardized and precise manner. Only one of 16 articles provided a method for estimating blood loss. Most of the articles were retrospective; the data were often incomplete or did not take into account the hospital treatment; only six out of 16 articles examined the visual estimation of the blood losses by the health care staff (prehospital and hospital setting); the majority of these articles used a blood-like product, which lacked all its typical characteristics (coagulation, viscosity, etc.) to simulate the scenario; and finally, out of 16 articles, only seven used simulation scenarios. CONCLUSIONS: Available parameters to assess early blood loss in the prehospital setting are insensitive and nonspecific. Blood loss assessment is restricted by use of legacy vital signs that remain unchanged during the compensatory stage of shock. The correlation between changes in vital signs and early hemorrhage is highly variable and dependent on interindividual responses. Using static standardized vital sign norms does little to identify the patient early in compensated shock. 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The golden hour of shock-how time is running out: Prehospital time intervals in Germany, a multivariate analysis of 15103 patients from the Trauma Register DGU. Emergency Medicine Journal , 30 (12), 1048 – 1055. doi:10.1136/emermed-2012-201962 Zarzaur B. L. Croce M. A. Fischer P. E. Magnotti L. J. Fabian P. C. (2008). New vitals after injury: Shock index for the young and age x shock index for the old. Journal of Surgical Research , 147 (2), 229 – 236. doi:10.1016/j.jss.2008.03.025 Zia J. Kimball J. Rolfes C. Hahn J. O. Inan O. T. (2020). Enabling the assessment of trauma-induced hemorrhage via smart wearable systems. Science Advances , 6 (30), eabb1708. doi:10.1126/sciadv.abb1708 [ABSTRACT FROM AUTHOR]

Background: We previously explained why acardiac twinning occurs in the first trimester. We raised the question why a sudden demised monochorionic twin beyond the first trimester does not lead to acardiac twinning. We argued that exsanguinated blood from the live twin would strongly increase the demised twins' vascular resistance, preventing its perfusion and acardiac onset. However, our current hypothesis is that perfusion of the demised twin does occur but that it is insufficient for onset of acardiac twinning. Methods: We analyzed blood pressures and flows in a vascular resistance model of a monochorionic twin pregnancy where one of the fetuses demised. The resistance model consists of a demised twin with a (former) placenta, a live twin and its placenta, and arterioarterial (AA) and venovenous placental anastomoses. We assumed that only twins with a weight of at least 33% of normal survived the first trimester and that exsanguination of more than 50% of its blood volume is fatal for the live twin. Results: At 20 weeks, only AA anastomoses with radii ≲1 mm keep the exsanguinated blood volume below 50%. Then, perfusion of the deceased body with arterial blood from the live fetus is about 5–40 times smaller than when that body was alive. Beyond 20 weeks, this factor is even smaller. At 14 weeks, this factor is at most 2. Conclusion: We hypothesize that this small perfusion flow of arterial blood prevents further growth of the deceased body and hence precludes onset of acardiac twinning. [ABSTRACT FROM AUTHOR]

ImportanceSeverely injured patients experiencing hemorrhagic shock often require massive transfusion. Earlier transfusion with higher blood product ratios (plasma, platelets, and red blood cells), defined as damage control resuscitation, has been associated with improved outcomes; however, there have been no large multicenter clinical trials.ObjectiveTo determine the effectiveness and safety of transfusing patients with severe trauma and major bleeding using plasma, platelets, and red blood cells in a 1:1:1 ratio compared with a 1:1:2 ratio.Design, setting, and participantsPragmatic, phase 3, multisite, randomized clinical trial of 680 severely injured patients who arrived at 1 of 12 level I trauma centers in North America directly from the scene and were predicted to require massive transfusion between August 2012 and December 2013.InterventionsBlood product ratios of 1:1:1 (338 patients) vs 1:1:2 (342 patients) during active resuscitation in addition to all local standard-of-care interventions (uncontrolled).Main outcomes and measuresPrimary outcomes were 24-hour and 30-day all-cause mortality. Prespecified ancillary outcomes included time to hemostasis, blood product volumes transfused, complications, incidence of surgical procedures, and functional status.ResultsNo significant differences were detected in mortality at 24 hours (12.7% in 1:1:1 group vs 17.0% in 1:1:2 group; difference, -4.2% [95% CI, -9.6% to 1.1%]; P = .12) or at 30 days (22.4% vs 26.1%, respectively; difference, -3.7% [95% CI, -10.2% to 2.7%]; P = .26). Exsanguination, which was the predominant cause of death within the first 24 hours, was significantly decreased in the 1:1:1 group (9.2% vs 14.6% in 1:1:2 group; difference, -5.4% [95% CI, -10.4% to -0.5%]; P = .03). More patients in the 1:1:1 group achieved hemostasis than in the 1:1:2 group (86% vs 78%, respectively; P = .006). Despite the 1:1:1 group receiving more plasma (median of 7 U vs 5 U, P

Objectives and Background: Pelvic fracture causes significant mortality and morbidities. The purpose of this study is to identify the characteristics of patients with pelvic fracture in Hong Kong and to determine the factors predicting mortality. The result could help to identify high-risk patients who might benefit from more intensive evaluation and intervention. Method: Five hundred and eight patients (age > 12 years old) with pelvic fractures were identified from the trauma registries of four designated trauma centres in Hong Kong from 1 January 2005 to 31 December 2012. Patient baseline characteristics and outcomes were analysed. Stepwise logistic regression was performed to identify independent clinical predictors for mortality. Result: Mean age was 45.4 ± 19.2 years, 43.3% were female, mean length of hospital stay was 27.9 ± 42.4 days and mean length of intensive care unit stay was 4.8 ± 6.8 days. Injury severity score was 28.9 ± 18.7, revised trauma score was 7.2 ± 2 and 30-day mortality was 20.9%. Stepwise logistic regression identified patient's age, presenting systolic blood pressure, initial Glasgow Coma Scale, injuries to the thoracic and abdominal regions, first base excess and the volume of red blood cell transfusion required within the first 6 h to be independent risk factors predicting mortality. Conclusion: Pelvic fracture is associated with significant risk of mortality in major trauma patients. Clinical characteristics obtained during emergency department resuscitation can help in selecting patients for timely aggressive interventions. [ABSTRACT FROM AUTHOR]

With over 9 billion broilers processed each year in the United States, blood is a significant by-product of poultry processing. An adequate bleed-out during slaughter with subsequent blood collection results in blood being redirected from the wastewater stream to rendering, less wastewater treatment needed at the processing plant, and more saleable by-product. There is relatively little current research into the effect of stunning method on blood loss and blood loss rate, particularly on today's high breast meat-yield broilers. This study aimed to determine the percent of blood loss and rate of blood loss for 3 stunning methods (alternating current [ AC ] electrocution, pulsed direct current [ DC ] electrical stun, and controlled atmosphere stun/kill [ CASK ]) across the 2 most commonly used neck cut methods (1-sided neck cut [ 1S ] and 2-sided neck cut [ 2S ]). Four trials of 120 birds each from separate flocks of male broilers at 62 d, 45 d, 43 d, and 43 d of age were stunned and then exsanguinated via 1S or 2S. Postneck cut, carcass weights were recorded in 15 s intervals for 180 s. In general, DC stunning resulted in significantly greater blood loss and rates of blood loss than either AC or CASK, whereas exsanguination method and treatment interactions had limited impact. Upon evisceration, a substantial proportion of residual blood in AC and CASK broiler carcasses was found to be in the viscera. These results highlight the need to closely revaluate bleed-out and blood collection processes when changing stunning method in broilers. [ABSTRACT FROM AUTHOR]

Abstract Background During total knee arthroplasty(TKA), tourniquet is widely used by most surgeons whereas the optimal application is still controversial. With this prospective randomized controlled study, we intend to investigate the effect of lower limb lifting and squeeze exsanguination methods on clinical outcomes in a series of TKAs. Methods Prospectively enrolled a total of 236 TKA patients from March, 2012 to November, 2016. Of which 118 patients randomly constitute Group A with lower limb lifting exsanguination technique; and the other 118 patients comprise Group B with squeeze exsanguination method. A year’s follow-up measurements were recorded in detail for analysis. Results The pre-tourniquet time of Group A was significantly shorter than that in Group B (P

Introduction: Arterio-oesophageal fistulae are a very uncommon cause of severe gastrointestinal bleeding, and mostly result from an aberrant right subclavian artery and mediastinal surgery or prolonged endotracheal/nasogastric intubation. Material and Methods: We present the case of a patient with an oesophageal adenocarcinoma and haematemesis due to a subclavian arterio-oesophageal fistula after mediastinal radiotherapy. Conclusion: We discuss the rare, life-threatening condition of acute erosion of the left subclavian artery caused by an oesophageal tumour and presenting with Chiari's triad.

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Background: During hemorrhage and resuscitation, clinical and laboratory monitoring is useful to guide further management. However, acute changes in the biochemistry due to blood loss and subsequent crystalloid fluid resuscitation have not been fully studied. Materials and methods: Twelve anesthetized, juvenile pigs were used. Atraumatic exsanguination, corresponding to a total blood loss of 40%, was performed through a catheter and completed 2 h after initiation of the experiment. Arterial samples were analyzed by point-of-care testing and venous samples were analyzed. Oxygen delivery was calculated. Results: Shortly after 40% hemorrhage and concomitant fluid supplementation, there were significant reductions in arterial hemoglobin and hematocrit (approximately 25%, respectively). Oxygen delivery was less than half of the baseline value. Lactate in arterial blood was more than doubled after 40% exsanguination. On average, no other clinically significant changes in any of the analytes were observed, but interindividual dispersion was pronounced. Conclusions: Acute exsanguination was associated with decreased hemoglobin and hematocrit levels and increased lactate levels but limited effects on the other biomarkers that were studied. Increased levels of biomarkers in severely bleeding patients could indicate tissue damage and the source should be further investigated. [ABSTRACT FROM AUTHOR]