AAST multicenter prospective analysis of prehospital tourniquet use for extremity trauma.

BACKGROUND: Tourniquet use for extremity hemorrhage control has seen a recent increase in civilian usage. Previous retrospective studies demonstrated that tourniquets improve outcomes for major extremity trauma (MET). No prospective study has been conducted to date. The objective of this study was to evaluate outcomes in MET patients with prehospital tourniquet use. We hypothesized that prehospital tourniquet use in MET decreases the incidence of patients arriving to the trauma center in shock. METHODS: Data were collected prospectively for adult patients with MET at 26 Level I and 3 Level II trauma centers from 2015 to 2020. Limbs with tourniquets applied in the prehospital setting were included in the tourniquet group and limbs without prehospital tourniquets were enrolled in the control group. RESULTS: A total of 1,392 injured limbs were enrolled with 1,130 tourniquets, including 962 prehospital tourniquets. The control group consisted of 262 limbs without prehospital tourniquets and 88 with tourniquets placed upon hospital arrival. Prehospital improvised tourniquets were placed in 42 patients. Tourniquets effectively controlled bleeding in 87.7% of limbs. Tourniquet and control groups were similarly matched for demographics, Injury Severity Score, and prehospital vital signs (p > 0.05). Despite higher limb injury severity, patients in the tourniquet group were less likely to arrive in shock compared with the control group (13.0% vs. 17.4%, p = 0.04). The incidence of limb complications was not significantly higher in the tourniquet group (p > 0.05). CONCLUSION: This study is the first prospective analysis of prehospital tourniquet use for civilian extremity trauma. Prehospital tourniquet application was associated with decreased incidence of arrival in shock without increasing limb complications. We found widespread tourniquet use, high effectiveness, and a low number of improvised tourniquets. This study provides further evidence that tourniquets are being widely and safely adopted to improve outcomes in civilians with MET. LEVEL OF EVIDENCE: Therapeutic/Care Management; Level IV.

[Preliminary discussion on the prevention and treatment of shock after severe burns].

Shock is one of the most common complications and one of the main causes of death after severe burns. The prevention and treatment of shock runs through the whole process of severe burn treatment. Shocks after severe burns, based on their causes, are mainly classified as follows: hypovolemic shock characterized by elevated hematocrit, also known as burn shock, and caused by serious leakage of intravascular fluid to body surface and interstitial spaces in the early stage of burns; hemorrhagic shock caused by large scale of incision and tension reduction, gastrointestinal stress ulcer, or large area of escharectomy and tangential excision surgery; septic shock caused by various microbial invasion; anaphylactic shock caused by infusion of drugs or blood. From the perspective of the reduction of effective circulating volume, burn shock and hemorrhagic shock are hypovolemic shocks, and septic shock and anaphylactic shock are vasodilatory shocks. As the aforementioned shocks vary in terms of occurrence timing, occurrence mechanism, and clinical manifestations, individualized strategies should be adopted for the prevention and treatment.

Thermodynamic interference with bile acid demicelleization reduces systemic entry and injury during cholestasis.

Bile acids (BA), with their large hydrophobic steroid nucleus and polar groups are amphipathic molecules. In bile, these exist as micelles above their critical micellar concentration (CMC). In blood at low concentrations, these exist as monomers, initiating cellular signals. This micellar to monomer transition may involve complex thermodynamic interactions between bile salts alone or with phospholipids, i.e. mixed micelles and the aqueous environment. We therefore went on to test if therapeutically relevant changes in temperature could influence micellar behavior of bile salts, and in turn whether this affected the biological responses in cells, and in vivo. Sodium taurocholate (STC) belongs to a major class of bile salts. STC has a CMC in the 5-8 mM range and its infusion into the pancreatic duct is commonly used to study pancreatitis. We thus studied micellar breakdown of STC using isothermal titration calorimetry (ITC), dynamic light scattering and cryogenic transmission electron microscopy. Under conditions relevant to the in vivo environment (pH 7.4, Na 0.15 M), ITC showed STC to have a U shaped reduction in micellar breakdown between 37 °C and 15 °C with a nadir at 25 °C approaching ≈90% inhibition. This temperature dependence paralleled pancreatic acinar injury induced by monomeric STC. Mixed micelles of STC and 1-palmitoyl, 2-oleyl phosphatidylcholine, a phospholipid present in high proportions in bile, behaved similarly, with ≈75% reduction in micellar breakdown at 25 °C compared to 37 °C. In vivo pancreatic cooling to 25 °C reduced the increase in circulating BAs after infusion of 120 mM (5%) STC into the pancreatic duct, and duct ligation. Lower BA levels were associated with improved cardiac function, reduced myocardial damage, shock, lung injury and improved survival independent of pancreatic injury. Thus micellar breakdown of bile salts is essential for their entry into the systemic circulation, and thermodynamic interference with this may reduce their systemic entry and consequent injury during cholestasis, such as from biliary pancreatitis.

Temperature gradients in domestic cats over seven-years-old: descriptive analysis / Avaliação descritiva dos gradientes de temperatura em felinos domésticos com mais de sete anos

The temperature gradients are dynamic and noninvasive monitoring techniques that provide information on peripheral blood flow and have been related to the prognosis of patients with circulatory shock. This study evaluated 47 elderly domestic cats' temperature gradients, and we measured central (rectal) and peripheral (palmar, plantar and medial region of the radio) temperatures. Values found in this study are compatible with studies in young felines and differ from dogs and humans. The mean gradients found were 7.5°C for the central-peripheral; 5.6°C for the peripheral-environmental; 2.7°C for the skin-diff; and 0°C for the member-diff and the variables age and gender do not seem to influence these measurements. To the authors' knowledge, there is no description of temperature gradients in elderly domestic cats, so this study pretends to clarify the vasoconstriction response in this group of animals.(AU)

Os gradientes de temperatura são técnicas de monitoração dinâmicas e não-invasivas que fornecem informações sobre o fluxo sanguíneo periférico, e têm sido relacionados ao prognóstico de paciente com choque circulatório. O presente estudo avaliou os gradientes de temperatura em 47 felinos domésticos idosos aferindo as temperaturas central (retal) e periférica (palmar, plantar e região medial do rádio). Os gradientes encontrados foram 7,5°C para o centro-periférico; 5,6°C para o periférico-ambiental; 2,7°C para o skin-diff; e 0°C para o member-diff. As variáveis idade e sexo não pareceram influenciar as mensurações. Não há, em conhecimento dos autores, descrição prévia dos gradientes de temperatura em felinos domésticos idosos, e por isso esse estudo pretende contribuir com o entendimento sobre a capacidade de resposta de vasoconstrição nesse grupo de animais.(AU)

MK2 phosphorylation of RIPK1 regulates TNF-mediated cell death.

TNF is a master proinflammatory cytokine whose pathogenic role in inflammatory disorders can, in certain conditions, be attributed to RIPK1 kinase-dependent cell death. Survival, however, is the default response of most cells to TNF stimulation, indicating that cell demise is normally actively repressed and that specific checkpoints must be turned off for cell death to proceed. We identified RIPK1 as a direct substrate of MK2 in the TNFR1 signalling pathway. Phosphorylation of RIPK1 by MK2 limits cytosolic activation of RIPK1 and the subsequent assembly of the death complex that drives RIPK1 kinase-dependent apoptosis and necroptosis. In line with these in vitro findings, MK2 inactivation greatly sensitizes mice to the cytotoxic effects of TNF in an acute model of sterile shock caused by RIPK1-dependent cell death. In conclusion, we identified MK2-mediated RIPK1 phosphorylation as an important molecular mechanism limiting the sensitivity of the cells to the cytotoxic effects of TNF.

Recurrence of non-cardiogenic pulmonary edema and sustained hypotension shock in cystic pheochromocytoma.

Pheochromocytoma is a rare neuroendocrine tumor which derives from chromaffin cells of the adrenal gland or relevant to sympathetic nerves and ganglia. The clinical features of pheochromocytoma are various. Paroxysmal episodes of serious hypertension, headache, palpitation, and diaphoresis are the typical manifestations (Bravo, 2004). Hypotension shock, pulmonary edema, and acute coronary syndrome induced by pheochromocytoma are uncommon (Malindretos et al., 2008; Batisse-Lignier et al., 2015). In this study, we present a rare case of cystic pheochromocytoma causing recurrent hypotension shock, non-cardiogenic pulmonary edema, and acute coronary syndrome, and the possible mechanisms are discussed.

Peri-procedural risk stratification and management of patients with Williams syndrome.

Williams syndrome (WS) is a congenital, multisystem disorder affecting the cardiovascular, connective tissue, and central nervous systems in 1 in 10 000 live births. Cardiovascular involvement is the most common cause of morbidity and mortality in patients with WS, and noninvasive and invasive procedures are common. Sudden cardiovascular collapse in patients with WS is a well-known phenomenon, especially in the peri-procedural period. Detailed guidelines for peri-procedural management of patients with WS are limited. The goal of this review is to provide thoughtful, safe and effective management strategies for the peri-procedural care of patients with WS with careful consideration of hemodynamic impacts of anesthetic strategies. In addition, an expanded risk stratification system for anesthetic administration is provided.

Craniosynostosis and Guanine Nucleotide-binding Protein Alpha Stimulating Mutation: Risk of Bleeding Diathesis and Circulatory Collapse in Patients Undergoing Cranial Vault Reconstruction.

Reconstruction of the craniosynostosis deformity is a relatively safe operation with low overall complication risks. Despite expected risk of significant blood loss, life-threatening bleeding is relatively rare, and there is a low incidence of reported deaths in the literature. Several modalities have been described for perioperative mitigation of blood loss and transfusion requirements. Due to the low overall risk of life-threatening bleeding and circulatory collapse, it is judicious that any potential causes of such unusual but potentially significant fatal bleeding complication be evaluated and reported to increase awareness for craniofacial surgeons treating these conditions. In this report and literature review, the authors present a highly unusual patient with significant bone bleeding and circulatory collapse in a metopic craniosynostosis patient with guanine nucleotide-binding protein alpha stimulating (GNAS) mutation; perform a literature review regarding bleeding diathesis in craniosynostosis patients with GNAS mutations; and suggest guidelines to potentially prevent mortality in such patients.

The prevention of circulatory collapse in left atrial myxoma or left atrail thrombus patients.

Some patients with myxoma or thrombus may develop to severe hypotension or sudden death. In this article, we hypothesize a clinical scenario that when the myxoma or thrombus blocks in the mitral valve and causes significant hypotension during anesthesia or surgery. Increasing cardiac preload will be an effective preventive method to increasing the mitral valve annulus and decreasing the severity of stenosis, as a result it will prevent circulatory collapse. Our hypothesis will decrease the possibility of lethal mitral valve stenosis induced by left atrial mass blocking the mitral valve area. In addition, we should also maintain a relative slow heart rate and a relative high systemic vascular resistance.

Preventable deaths and potentially preventable deaths. What are our errors?

BACKGROUND: A variety of systems have been applied to identify and address errors in the management of multiple trauma patients. This lack of standardisation represents a serious problem. OBJECTIVES: Detect preventable and potentially preventable deaths, and classify all the errors with universal language. METHODS: We studied all trauma patients over 16 admitted to the critical care unit or who died before. In multidisciplinary sessions we decided which deaths were preventable, potentially preventable and non preventable. Guided by ATLS protocols, we detected errors in their management that were classified using the taxonomy of Joint Commission. RESULTS: We registered 1236 trauma patients (ISS 20.77). Of the 115 trauma deaths, 19 were preventable or potentially preventable deaths. We recorded 130 errors in all deaths, 46 of them in preventable or potentially preventable deaths. Using our own classification, the main errors were delay in starting correct treatment or performance of CT in hemodynamically unstable patients. Using the taxonomy of Joint Commission, the main type error was clinical, during the intervention: the delay in initiating correct treatment. Mistakes were made in the emergency department by medical specialists. The incidence of therapeutic and diagnostic errors was similar. The main cause of error was human failure, specifically 'rule-based' errors CONCLUSIONS: Measuring and recording the results is the first step on the way to improving the quality of care for trauma patients. A common language like the taxonomy of Joint Commission will help standardise patient safety data, thus improving the recording of incidents and their analysis and treatment.

Pulmonary Vasodilators in the Management of Low Cardiac Output Syndrome After Pediatric Cardiac Surgery.

Pulmonary hypertension is among the causes of low cardiac output syndrome after neonatal and pediatric cardiac surgery. In the setting of transient postoperative myocardial dysfunction, even a moderate elevation of pulmonary pressure can result in heart dysfunction and circulatory collapse. Although, specific pharmacological manipulation of pulmonary vascular resistance is frequently required in the perioperative period, there is no widely standardized management. In this review, a systematic literature search of PubMed and MEDLINE databases using relevant terms was performed. All clinical trials and relevant manuscripts, along with important physiological, pharmacological, and evidence-based considerations involving the use of pulmonary vasodilators in the management of low cardiac output syndrome after cardiac surgery were reviewed. This article addresses the fifth of eight topics comprising the special issue entitled "Pharmacologic strategies with afterload reduction in low cardiac output syndrome after pediatric cardiac surgery".

Comparison of three techniques for calculation of the Parkland formula to aid fluid resuscitation in paediatric burns.

CONTEXT: Inadequate fluid resuscitation of acute burns may result in hypovolaemic shock. Excessive fluid resuscitation may result in fluid overload. A nomogram which uses the popular Parkland formula and '4-2-1' regime has been recently described to facilitate the calculation of fluid requirements in children during the first 24 h following burn injury. OBJECTIVE: To compare the accuracy and speed of calculation of three different methods (pen and paper, electronic calculator and nomogram), which all use the Parkland formula and '4-2-1' regime to calculate maintenance and resuscitation fluid requirements for children in the first 24 h after burn injury. DESIGN: A randomised volunteer study using computer-generated simulated patient data. SETTING: Welsh Centre for Burns, ABM University Local Health Board, Swansea, UK. Data were collected between February 2011 and October 2011. PARTICIPANTS: The group consisted of 36 volunteers including trainee and consultant surgeons and anaesthetists. INTERVENTION: Thirty-six participants performed 318 calculations, using each of the three methods of calculation up to three times. MAIN OUTCOME MEASURES: Accuracy, speed and acceptability of the different methods. RESULTS: For nomogram, calculator and pen and paper: magnitude of error [low (≥25%), medium (≥50%) and high (≥75%)]: [5.7, 4.7 and 3.8%], [12.1, 12.1 and 7.5%], [28.6, 21.9 and 16.2%]; [P <0.001, P = 0.001 and P = 0.006]. Calculation time: [s; mean (SD)]: 121 (48), 109 (52) and 240 (140); P <0.001. The mean (SD) of the difficulty scores were 17.3 (13), 20.6 (13.4) and 62.2 (23.4); P <0.001. CONCLUSION: The nomogram was the most accurate method of calculating fluid requirements using the Parkland formula, was only slightly slower than the electronic calculator and was deemed the easiest to use. The nomogram is also low cost, robust, and provides a rapid means of detecting and preventing the large errors that we have shown can occur when an electronic device is used as the primary method of resuscitation fluid calculation. We, therefore, suggest that the nomogram is a suitable method for the calculation of the Parkland formula to guide resuscitation and maintenance fluid requirements in the first 24 h of paediatric burns or for cross-checking the results obtained by other means of calculation.

Predicting haemorrhage in pre-hospital traumatic patients: evaluation of the novel heart-to-arm time index.

BACKGROUND: Early recognition of hypovolaemia in trauma patients is very important. However, the most often used clinical signs, such as hypotension and tachycardia, lack specificity and sensitivity. METHODS: We propose a non-invasive index of hypovolaemia, the heart to arm time (iHAT), based on a modified pulse transit time indexed to heart rate. Pulse transit time is the sum of pre-ejection period and vascular transit time. Following pre-load reductions due to hypovolaemia, ventricular diastolic filling time increases causing an increase in pre-ejection-period, pulse transit time, and hence iHAT. One hundred and four consecutive patients with suspected major trauma were enrolled. The primary aim was to evaluate the use of the iHAT for detecting haemorrhage in major trauma. The secondary end point was to compare the specificity and sensitivity of iHAT compared to commonly used indexes. RESULTS: iHAT was calculated in 84 subjects, 11 of whom were haemorrhagic. iHAT discriminated haemorrhagic from non-haemorrhagic group (46.8% vs. 66.9%, P < 0.0001). The cut-off for iHAT with the best compromise between sensitivity (90.9%) and specificity (100%) was reached at the 58.78% level. Comparing haemorrhagic and non-haemorrhagic patients, the area under the ROC curve was 0.952 for iHAT, 0.835 for heart rate, and 0.911 for systolic blood pressure, showing no significant differences. CONCLUSIONS: iHAT is a non-invasive index that can identify haemorrhage in trauma patients with high sensitivity and specificity. These data should be considered as an exploration, but any conclusion should be validated in a new set of consecutive patients.

High-dose perioperative corticosteroids in steroid-treated patients undergoing major colorectal surgery: necessary or overkill?

BACKGROUND: Steroid-treated patients undergoing major colorectal surgery are routinely treated with high-dose steroids (HDS) to prevent perioperative adrenal insufficiency and cardiovascular collapse. However, there is no evidence to support this practice. METHODS: A retrospective analysis of 97 consecutive steroid-treated patients with inflammatory bowel disease who underwent major colorectal surgery was performed. The incidence of hemodynamic instability and surgical outcomes were compared in patients treated with perioperative low-dose steroids (LDS) versus HDS. RESULTS: Forty-three patients were treated with HDS, and 54 patients received LDS. There was no significant difference in hemodynamic instability between HDS-treated (74%) and LDS-treated (78%) patients. No patients required rescue HDS for adrenal insufficiency. CONCLUSIONS: Steroid-treated patients with inflammatory bowel disease undergoing major colorectal surgery appear to have no clinically significant hemodynamic instability when managed with LDS versus HDS. A prospective study assessing perioperative steroid dosing in patients with inflammatory bowel disease is in progress.

Melanocortins as potential therapeutic agents in severe hypoxic conditions.

Melanocortin peptides with the adrenocorticotropin/melanocyte-stimulating hormone (ACTH/MSH) sequences and synthetic analogs have protective and life-saving effects in experimental conditions of circulatory shock, myocardial ischemia, ischemic stroke, traumatic brain injury, respiratory arrest, renal ischemia, intestinal ischemia and testicular ischemia, as well as in experimental heart transplantation. Moreover, melanocortins improve functional recovery and stimulate neurogenesis in experimental models of cerebral ischemia. These beneficial effects of ACTH/MSH-like peptides are mostly mediated by brain melanocortin MC(3)/MC(4) receptors, whose activation triggers protective pathways that counteract the main ischemia/reperfusion-related mechanisms of damage. Induction of signaling pathways and other molecular regulators of neural stem/progenitor cell proliferation, differentiation and integration seems to be the key mechanism of neurogenesis stimulation. Synthesis of stable and highly selective agonists at MC(3) and MC(4) receptors could provide the potential for development of a new class of drugs for a novel approach to management of severe ischemic diseases.

Early initiation of arginine vasopressin infusion in neonates after complex cardiac surgery.

OBJECTIVE: To describe our experience with low-dose arginine vasopressin infusions (0.0003 U/kg/min) initiated in the operating room after the Norwood procedure or arterial switch operation. DESIGN: Retrospective cohort study of 37 consecutive neonates. SETTING: Pediatric cardiovascular intensive care unit in a tertiary hospital. SUBJECTS: Nineteen patients that received low-dose arginine vasopressin infusion instituted in the operating room (arginine vasopressin+) were compared to 18 patients that did not receive early arginine vasopressin infusion (arginine vasopressin-). INTERVENTIONS: None. RESULTS: When comparing arginine vasopressin+ and arginine vasopressin- in the first 24 hrs after cardiovascular intensive care unit admission, there was no difference in demographic variables, heart rate, blood pressure, central venous pressure, maximum lactate, maximum arterial and central venous saturation difference, urine output, chest tube output, or peritoneal drain output. Mean fluid resuscitation in the first 24 hrs was significantly lower in the arginine vasopressin+ group compared to the arginine vasopressin- group (182 ± 61 mL/kg vs. 223 ± 53 mL/kg, p = .03). The arginine vasopressin+ group also reached median net negative cumulative fluid balance sooner (55 hrs: interquartile range 45, 74 vs. 76 hrs: interquartile range 69, 92; p = .02). Median maximum inotrope score in the first 24 hrs was significantly lower in arginine vasopressin+ (9: interquartile range 5, 12.5 vs. 16.5: interquartile range 10.3, 22.1; p = .02). There was a nonsignificant trend toward shorter duration of mechanical ventilation and cardiovascular intensive care unit length of stay in the arginine vasopressin+ group. The lowest serum sodium in the first 48 hrs was significantly lower in arginine vasopressin+ (132 vs. 137 mmol/L, p = .01). CONCLUSION: Low-dose arginine vasopressin infusion initiated in the operating room after complex neonatal cardiac surgery was associated with decreased fluid resuscitation and catecholamine requirements in the first 24 postoperative hours.

[Experience in surgical management of posttraumatic arteriovenous aneurysms of the aortorenal zone].

Presented herein are two clinical case reports concerning surgical management of posttraumatic arteriovenous aneurysms of the juxtarenal portion of the aorta and left renal vein, demonstrating the informative value of multispiral computed angiography in diagnosis of the pathology involved. Two patients presenting with a stab-and-lacerated wound of the abdominal cavity and subjected to comprehensive examination were found to have an arteriovenous anastomosis between the aorta and left renal vein with the formation of an up to 35-mm aneurysm in one case, and an arteriovenous anastomosis between the left renal artery and left renal vein with the formation of a pseudoaneurysm sized up to 30 mm in the other. Both patients had a clinical picture of cardiopulmonary insufficiency induced by overloading of the right portions of the heart. Both pathologies were treated surgically in the scope of removing the arteriovenous anastomosis and aneurysm of the juxtarenal portion of the abdominal aorta and left renal artery. The postoperative period showed nothing to report and turned out uneventful, with the patients being discharged from the clinic in a satisfactory condition with good laboratory and haemodynamic parameters.

[Diagnostic performance of colonoscopy in lower gastrointestinal bleeding]. / Rendimiento de la colonoscopia en la hemorragia digestiva baja.

Lower gastrointestinal bleeding is a common medical emergency that usually has a favorable prognosis. However, these events generate high resource use. The procedure of choice is colonoscopy with prior colonic preparation due to its high diagnostic performance and safety and the possibility of endoscopic therapy. Emergency colonoscopy has advantages over elective colonoscopy, showing higher diagnostic yield and superior detection of stigmata of recent bleeding, increasing the probability of endoscopic treatment. Predictive models of bleeding severity and recurrence have been published, allowing resource use to be rationalized, mainly by reducing hospital stay in low-risk patients. Nevertheless, the optimal timing of emergency colonoscopy has not been established and the impact of endoscopic treatment on prognosis is controversial.