Fluid resuscitation in trauma: what are the best strategies and fluids?

Process Mining Uncovers Actionable Patterns of Red Blood Cell Unit Wastage in a Health Care Network

Packed red blood cell transfusions are integral to the care of the critically and chronically ill patient, but require careful storage and a large, coordinated network to ensure their integrity during distribution and administration. Auditing a Transfusion Medicine service can be challenging due to the complexity of this network. Process mining is an analytical technique that allows for the identification of high-efficiency pathways through a network, as well as areas of challenge for targeted innovation. Here, we detail a case study of an efficiency audit of the Transfusion Medicine service of the Nova Scotia Health Administration Central Zone using process mining, across a period encompassing years prior to, during, and after the acute COVID-19 pandemic. Service efficiency from a product wastage perspective was consistently demonstrated at benchmarks near globally published optima. Furthermore, we detail key areas of continued challenge in product wastage, and suggest potential strategies for further targeted optimization.

The impact of pre-rehydration guided by carotid corrected flow time on hypotension prevention following general anesthesia induction in patients undergoing gastrointestinal surgery: a prospective randomized controlled trial

Background

Patients undergoing gastrointestinal surgery often experience hypotension following general anesthesia induction due to insufficient volume. This study aimed to assess whether pre-rehydration guided by carotid corrected flow time (FTc) could mitigate post-induction hypotension induced by general anesthesia.

Methods

Patients undergoing resection of gastrointestinal tumors were assigned to either the conventional treatment group (Group C) or the fluid treatment group based on FTc (Group F). Within Group F, patients were further divided into Group A (carotid FTc <340.7 ms) and Group B (carotid FTc ≥340.7 ms) based on pre-rehydration carotid FTc values. Group A patients received pre-rehydration with 250 mL of colloids (hydroxyethyl starch-HES) administered within 15 min until carotid FTc reached ≥340.7 ms to counteract hypovolemia prior to induction. Patients in Group B and Group C received a continuous HES infusion at a rate of 6 mL/kg/h 30 min before induction to compensate for physiological fluid loss. All patients received a perioperative background infusion of 3 mL/kg/h compound sodium chloride, with infusion rates optimized based on mean arterial pressure (MAP) and heart rate (HR). The incidence of post-induction hypotension was compared between Group C and Group F, as well as between Group A and Group B.

Results

The incidence of hypotension after induction was significantly lower in Group F compared to Group C (26.4% vs. 46.7%, respectively; p < 0.001). Patients in Group A received significantly more pre-rehydration, leading to a greater increase in carotid FTc values compared to Group B (336.5 ± 64.5 vs. 174.3 ± 34.1 ms, p = 0.002). However, no significant difference in carotid FTc values after pre-rehydration was observed between the groups. There was no significant difference in the incidence of hypotension after general anesthesia induction between Group A and Group B (22.9% vs. 28.8%, p = 0.535).

Conclusion

Pre-rehydration based on FTc can effectively reduce the occurrence of post-induction hypotension in patients undergoing gastrointestinal surgery who present with insufficient volume.

Clinical trial registration

https://www.chictr.org.cn/showprojEN.html?proj=201481.

4A after access: a new mnemonic to aid timely administration of IV/IO treatment in trauma patients

Administration of medication is a well-established part of prehospital trauma care. Guidance varies on the types of recommended medications and when they should be administered. Mnemonics have become commonplace in prehospital medicine to facilitate recall and retention. However, there is no comprehensive aid for the administration of medication in trauma patients. We propose a new mnemonic for the delivery of relevant intravenous or intraosseous medications in trauma patients. A '4A after Access' approach should enhance memory recall for the efficient provision of patient care. These 4As are: antifibrinolysis, analgesia, antiemesis and antibiotics. This mnemonic is designed to be used as an optional aide memoire in conjunction with existing treatment algorithms in the military prehospital setting.

Impact of Immunopathy and Coagulopathy on Multi-Organ Failure and Mortality in a Lethal Porcine Model of Controlled and Uncontrolled Hemorrhage

Uncontrolled hemorrhage is a major preventable cause of death in patients with trauma. However, the majority of large animal models of hemorrhage have utilized controlled hemorrhage rather than uncontrolled hemorrhage to investigate the impact of immunopathy and coagulopathy on multi-organ failure (MOF) and mortality. This study evaluates these alterations in a severe porcine controlled and uncontrolled hemorrhagic shock (HS) model. Anesthetized female swine underwent controlled hemorrhage and uncontrolled hemorrhage by partial splenic resection followed with or without lactated Ringer solution (LR) or Voluven® resuscitation. Swine were surveyed 6 h after completion of splenic hemorrhage or until death. Blood chemistry, physiologic variables, systemic and tissue levels of complement proteins and cytokines, coagulation parameters, organ function, and damage were recorded and assessed. HS resulted in systemic and local complement activation, cytokine release, hypocoagulopathy, metabolic acidosis, MOF, and no animal survival. Resuscitation with LR and Voluven® after HS improved hemodynamic parameters (MAP and SI), metabolic acidosis, hyperkalemia, and survival but resulted in increased complement activation and worse coagulopathy. Compared with the LR group, the animals with hemorrhagic shock treated with Voluven® had worse dilutional anemia, coagulopathy, renal and hepatic dysfunction, increased myocardial complement activation and renal damage, and decreased survival rate. Hemorrhagic shock triggers early immunopathy and coagulopathy and appears associated with MOF and death. This study indicates that immunopathy and coagulopathy are therapeutic targets that may be addressed with a high-impact adjunctive treatment to conventional resuscitation.

Adenosine, lidocaine and Mg2+ update: teaching old drugs new tricks

If a trauma (or infection) exceeds the body's evolutionary design limits, a stress response is activated to quickly restore homeostasis. However, when the injury severity score is high, death is often imminent. The goal of this review is to provide an update on the effect of small-volume adenosine, lidocaine and Mg2+ (ALM) therapy on increasing survival and blunting secondary injury after non-compressible hemorrhagic shock and other trauma and infective/endotoxemic states. Two standout features of ALM therapy are: (1) resuscitation occurs at permissive hypotensive blood pressures (MAPs 50-60 mmHg), and (2) the drug confers neuroprotection at these low pressures. The therapy appears to reset the body's baroreflex to produce a high-flow, hypotensive, vasodilatory state with maintained tissue O2 delivery. Whole body ALM protection appears to be afforded by NO synthesis-dependent pathways and shifting central nervous system (CNS) control from sympathetic to parasympathetic dominance, resulting in improved cardiovascular function, reduced immune activation and inflammation, correction of coagulopathy, restoration of endothelial glycocalyx, and reduced energy demand and mitochondrial oxidative stress. Recently, independent studies have shown ALM may also be useful for stroke, muscle trauma, and as an adjunct to Resuscitative Endovascular Balloon Occlusion of the Aorta (REBOA). Ongoing studies have further shown ALM may have utility for burn polytrauma, damage control surgery and orthopedic surgery. Lastly, we discuss the clinical applications of ALM fluid therapy for prehospital and military far-forward use for non-compressible hemorrhage and traumatic brain injury (TBI).

The efficacy of prehospital IV fluid management in severely injured adult trauma patients: a systematic review and meta-analysis

PURPOSE

The most widely used prehospital strategy for the management of hemorrhagic shock or trauma accompanied by hypotension is fluid resuscitation. Though current guidelines suggest early and aggressive fluid resuscitation, contemporary literature suggests a more restrictive approach. Our objective was to evaluate the effectiveness of low/ no IV fluids in comparison to standard resuscitation in reducing mortality for trauma patients in the prehospital setting.

METHODS

Population-adults with blunt or penetrating trauma in the prehospital setting with severe injury (defined as SBP < 90 mm Hg and/or a shock index > (1). Intervention-low-dose/no IV fluids. Comparison-standard resuscitation. Outcome-mortality. A librarian-assisted search of five databases (Medline, Embase, Web of Science, and CINAHL, Cochrane trials) was completed in June 2021 (updated in November 2022). ROBINS-1 and ROB-2 tools were used to assess risk of bias in observational and randomized studies, respectively. An inverse variance method and random-effects model of statistical analysis were utilized, with data reported as risk ratios with related 95% confidence intervals. Heterogeneity of studies was assessed through analysis of the I² RESULTS: Seven studies (six observational and one randomized trial) were included, with three thousand and fifty study participants included for analysis. Four studies compared high- to low-dose fluids, and three compared fluids to no fluids. We found no difference in mortality when comparing standard resuscitation to restricted resuscitation (RR 0.99, 95% CI [0.80-1.22], I² = 54%).

CONCLUSION

Weak, primarily observational evidence suggests that standard fluid resuscitation has no significant mortality benefit over restricting/withholding IV fluids in severe/hypotensive trauma. This review adds evidence to questioning the requirement for IV fluids in trauma given the lack of mortality benefit, in addition to demonstrating the need for more randomized studies in this area.

Perioperative colloids: From theory to practice

INTRODUCTION

Fluid administration is the cornerstone in hypovolemic patient's reanimation. Clinical guidelines restrict colloid administration favouring crystalloids. Currently, we don't know exactly which is the daily clinical practice during the perioperative period. The objective of this study is to describe perioperative use of colloids analysing possible reasons aiming to use them.

MATERIAL AND METHODS

Prospective, cross-section, national, multicentre observational study. Fluid Day sub-study. We enrolled all patient's older than 18 years old who underwent surgery during the 24 h of the 2-days study (February, 2019, 18th and 20th). We registered demographic data, comorbidities, anaesthetic and surgical procedure data, fluids administered, perioperative bleeding and monitoring type used during the perioperative period.

RESULTS

A total of 5928 cases were analysed and 542 patients (9.1%) received any type of colloids, being hydroxiethyl-starch the most frequently used (5.1%). Patients receiving colloids suffered more longing surgery (150 [90-255] vs. 75 [45-120] min), were urgently operated (13.7 vs. 7.5%) and were more frequent classified as high risk (22 vs. 4.8%). Their recovery was mostly in critical care units (45.1 vs.15.8%). Patients with bleeding less than 500 ml received colloids in a percentage of 5.9 versus 45.9% when this figure was overcome. Patients who received colloids were anaemic more frequently: 29.4 vs. 16.3%. Colloids administration had a higher risk for transfusion (OR 15.7). Advanced monitoring also increased the risk for receiving colloids (OR 9.43).

CONCLUSIONS

In our environment with routine clinical practice, colloids administration is limited and close linked to perioperative bleeding.

Mechanistic considerations for adenosine-lidocaine-magnesium (ALM) in controlling coagulopathy

Adenosine-lidocaine-magnesium (ALM) mixture is a cardioplegic agent that improves survivability in rodent, but not swine, models of noncompressible torso hemorrhage (NCTH). However, despite protection from comorbid coagulopathy being the one common effect reported in both NCTH models, the underlying prothrombotic mechanism for ALM has not been elucidated in either. Here, we undertook a component-based approach focusing on individual drugs in the mixture to elaborate on the protective mechanism against coagulopathy within the frames of adenosine signaling and metabolic pathways. Additionally, the translational potential of small and large animal models of NCTH for human survival is critically appraised, owing to substantial quantitative/qualitative differences between humans and rodents, particularly regarding the genetics of G protein-coupled receptors (GPCRs) interacting with ALM's constituents.

Predictive Factors of Outcome in Cases of Out-of-hospital Cardiac Arrest Due to Traffic Accident Injuries in Thailand; a National Database Study

INTRODUCTION

Traffic accident injury is one of the global leading causes of death and an important public health problem. This study aimed to evaluate the predictive factors of return of spontaneous circulation (ROSC) at the scene in out-of-hospital cardiac arrest (OHCA) due to traffic accidents.

METHODS

This retrospective cross-sectional study was conducted on cases of OHCA due to traffic accident, who were resuscitated at the scene by emergency medical services (EMS) in Bankok, Thiland, from January 1, 2020, to December 31, 2020 (1 year). Patients were divided into two groups of with and without ROSC and independent predictive factors of outcome were evaluated.

RESULTS

2400 OHCA cases met the inclusion criteria, among them, 1728 (72.0%) achieved ROSC at the scene. Facial injury (adjusted OR = 2.17, 95%CI: 1.37-3.44, p = 0.001); prehospital airway management using bag valve mask (adjusted OR = 1.69, 95%CI: 1.21-2.34, p = 0.002), and endotracheal tube (adjusted OR = 3.88, 95%CI: 1.84-8.18, p <0.001); and prehospital fluid therapy using normal saline (adjusted OR = 4.24, 95%CI: 3.12-5.77, p <0.001), ringer lactate (adjusted OR = 5.13, 95%CI: 3.47-7.61, p <0.001), and other solutions (adjusted OR = 5.25, 95%CI: 2.16-12.8, p <0.001) were independent predictive factors of ROSC at the scene in OHCA due to traffic accidents.

CONCLUSION

Based on the findings, the rate of ROSC at the scene for cases with OHCA due to traffic accidents, serviced by EMS was high, i.e., 72%, and three independent predictive factors of ROSC at the scene were facial injury, prehospital airway management, and prehospital fluid management.

Major Risk Factors for Mortality in Elderly and Non-Elderly Adult Patients Emergently Admitted for Blunt Chest Wall Trauma: Hospital Length of Stay as an Independent Predictor

Background: Blunt thoracic trauma is responsible for 35% of trauma-related deaths in the United States and significantly contributes to morbidity and healthcare-related financial strain. The goal of this study was to evaluate factors influencing mortality in patients emergently admitted with the primary diagnosis of blunt chest wall trauma. Methods: Adults emergently admitted for blunt chest trauma were assessed using the National Inpatient Sample Database, 2004–2014. Data regarding demographics, comorbidities, and outcomes were collected. Relationships were determined using univariable and multivariable logistic regression models. Results: In total, 1120 adult and 1038 elderly patients emergently admitted with blunt chest trauma were assessed; 46.3% were female, and 53.6% were male. The average ages of adult and elderly patients were 46.6 and 78.9 years, respectively. Elderly and adult patients both displayed mortality rates of 1%. The regression model showed HLOS and several comorbidities as the main risk factors of mortality Every additional day of hospitalization increased the odds of mortality by 9% (OR = 1.09, 95% CI = 1.01–1.18, p = 0.033). Mortality and liver disease were significantly associated (OR = 8.36, 95% CI = 2.23–31.37, p = 0.002). Respiratory disease and mortality rates demonstrated robust correlations (OR = 7.46, 95% CI = 1.63–34.11, p = 0.010). Trauma, burns, and poisons were associated with increased mortality (OR = 3.72, 95% CI = 1.18–11.71, p = 0.025). The presence of platelet/white blood cell disease correlated to higher mortality. (OR = 4.42, 95% CI = 1.09–17.91, p = 0.038).

Cold-stored platelets are effective in an in vitro model of massive transfusion protocol assessed by rotational thromboelastometry

BACKGROUND

Platelets are a key component of massive transfusion in treating actively bleeding patients. While optimized for prophylactic transfusions, the effectiveness of the current standard room temperature stored platelets (RPs) in treating actively bleeding patients is not clear. Cold-stored platelets (CPs) have been shown to have superior hemostatic functions and the potential to extend shelf life. In this study, we explored the effect of using CPs versus RPs in an in vitro transfusion model based on the massive transfusion protocol.

STUDY DESIGN AND METHODS

RPs or CPs were combined with RBCs and plasma in a 1:1:1 volume ratio to make transfusion packages. Whole blood was collected and then either diluted to 20% hematocrit or mixed with tPA (8.8 μg/ml). By volume, 70% of transfusion package was mixed with 30% whole blood to simulate massive transfusions and analyzed by rotational thromboelastometry. Transfusion package supernatant was analyzed for PAI-1 activity as well.

RESULTS

Both transfusion packages restored the clot characteristics of hemodiluted or hyperfibrinolytic whole blood. Specifically, only transfusion packages made with CPs significantly reduced the maximum clot lysis of hyperfibrinolytic whole blood. PAI-1 activity in CPs transfusion packages were also significantly higher.

DISCUSSION

Transfusion packages containing cold-stored platelets may be able to restore the blood hemostatic profile of bleeding patients. In addition, transfusion packages made from CPs may provide additional benefit of resisting hyperfibrinolysis in bleeding patients. In trauma where post-transfusion platelet recovery is less of a concern, CPs are a viable option to restore hemostasis.

Recovery of organ-specific tissue oxygen delivery at restrictive transfusion thresholds after fluid treatment in ovine haemorrhagic shock

Background

Fluid resuscitation is the standard treatment to restore circulating blood volume and pressure after massive haemorrhage and shock. Packed red blood cells (PRBC) are transfused to restore haemoglobin levels. Restoration of microcirculatory flow and tissue oxygen delivery is critical for organ and patient survival, but these parameters are infrequently measured. Patient Blood Management is a multidisciplinary approach to manage and conserve a patient’s own blood, directing treatment options based on broad clinical assessment beyond haemoglobin alone, for which tissue perfusion and oxygenation could be useful. Our aim was to assess utility of non-invasive tissue-specific measures to compare PRBC transfusion with novel crystalloid treatments for haemorrhagic shock.

Methods

A model of severe haemorrhagic shock was developed in an intensive care setting, with controlled haemorrhage in sheep according to pressure (mean arterial pressure 30–40 mmHg) and oxygen debt (lactate > 4 mM) targets. We compared PRBC transfusion to fluid resuscitation with either PlasmaLyte or a novel crystalloid. Efficacy was assessed according to recovery of haemodynamic parameters and non-invasive measures of sublingual microcirculatory flow, regional tissue oxygen saturation, repayment of oxygen debt (arterial lactate), and a panel of inflammatory and organ function markers. Invasive measurements of tissue perfusion, oxygen tension and lactate levels were performed in brain, kidney, liver, and skeletal muscle. Outcomes were assessed during 4 h treatment and post-mortem, and analysed by one- and two-way ANOVA.

Results

Each treatment restored haemodynamic and tissue oxygen delivery parameters equivalently (p > 0.05), despite haemodilution after crystalloid infusion to haemoglobin concentrations below 70 g/L (p < 0.001). Recovery of vital organ-specific perfusion and oxygen tension commenced shortly before non-invasive measures improved. Lactate declined in all tissues and correlated with arterial lactate levels (p < 0.0001). The novel crystalloid supported rapid peripheral vasodilation (p = 0.014) and tended to achieve tissue oxygen delivery targets earlier. PRBC supported earlier renal oxygen delivery (p = 0.012) but delayed peripheral perfusion (p = 0.034).

Conclusions

Crystalloids supported vital organ oxygen delivery after massive haemorrhage, despite haemodilution to < 70 g/L, confirming that restrictive transfusion thresholds are appropriate to support oxygen delivery. Non-invasive tissue perfusion and oximetry technologies merit further clinical appraisal to guide treatment for massive haemorrhage in the context of Patient Blood Management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40635-022-00439-6.

Automated Assessment of Cardiovascular Sufficiency Using Non-Invasive Physiological Data

For fluid resuscitation of critically ill individuals to be effective, it must be well calibrated in terms of timing and dosages of treatments. In current practice, the cardiovascular sufficiency of patients during fluid resuscitation is determined using primarily invasively measured vital signs, including Arterial Pressure and Mixed Venous Oxygen Saturation (SvO2), which may not be available in outside-of-hospital settings, particularly in the field when treating subjects injured in traffic accidents or wounded in combat where only non-invasive monitoring is available to drive care. In this paper, we propose (1) a Machine Learning (ML) approach to estimate the sufficiency utilizing features extracted from non-invasive vital signs and (2) a novel framework to address the detrimental impact of inter-patient diversity on the ability of ML models to generalize well to unseen subjects. Through comprehensive evaluation on the physiological data collected in laboratory animal experiments, we demonstrate that the proposed approaches can achieve competitive performance on new patients using only non-invasive measurements. These characteristics enable effective monitoring of fluid resuscitation in real-world acute settings with limited monitoring resources and can help facilitate broader adoption of ML in this important subfield of healthcare.

The Role of Nitric Oxide in the Efficacy of Adenosine, Lidocaine, and Magnesium Treatment for Experimental Hemorrhagic Shock in Rats

Background

Nitric oxide (NO) plays multiple roles regulating the central nervous, cardiovascular, and immune systems.

Objective

Our aim was to investigate the role of NO in the efficacy of hypertonic saline (7.5% sodium chloride [NaCl]) adenosine, lidocaine, and magnesium (ALM) to improve mean arterial pressure (MAP) and heart rate following hemorrhagic shock.

Methods

One hundred one male Sprague-Dawley rats (mean [SD] weight = 425 [6] g) were randomly assigned to 20 groups (groups of 4–8 rats each). Hemorrhagic shock (MAP < 40 mm Hg) was induced by 20-minute pressure-controlled bleeding (∼40% blood volume), and the animal was left in shock (MAP = 35-40 mm Hg) for 60 minutes. The NO synthase (NOS) inhibitor L-NAME was administered with a 0.3-mL bolus of different combinations of 7.5% NaCl ALM active ingredients and hemodynamic parameters were monitored for 60 minutes. A number of specific NOS and NO inhibitors were tested.

Results

We found that 7.5% NaCl ALM corrected MAP after hemorrhagic shock. In contrast, the addition of L-NAME to 7.5% NaCl ALM led to a rapid fall in MAP, sustained ventricular arrhythmias, and 100% mortality. Saline controls receiving 7.5% NaCl with N^G-nitro-l-arginine methyl ester (L-NAME) showed improved MAP with no deaths. None of the specific NOS and NO inhibitors mimicked L-NAME's effect on ALM. The addition of inducible NOS inhibitor 1400W to 7.5% NaCl ALM failed to resuscitate, whereas the NO scavenger PTIO and the PI3K inhibitor wortmannin reduced MAP recovery during 60-minute resuscitation.

Conclusions

The ability of 7.5% NaCl ALM to resuscitate appears to be linked to 1 or more NO-producing pathways. Nonspecific NOS inhibition with L-NAME blocked ALM resuscitation and led to cardiovascular collapse. More studies are required to examine NO site-specific contributions to ALM resuscitation. (Curr Ther Res Clin Exp. 2022; 82:XXX–XXX)

Traumatic Suprahepatic inferior vena cava injury survival of a rare case

Traumatic supra-hepatic inferior vena cava (IVC) injury is rare and nearly universally fatal. We report an excellent outcome from a case involving severe injury of the suprahepatic and intra-pericardial IVC utilizing emergency cardiopulmonary bypass (CPB) with deep hypothermic circulatory arrest.

The goal of this case report is to outline key factors that facilitated the patient's survival of extensive IVC injury. We conclude that aggressive prehospital fluid resuscitation, facile transfer to the operating room, early detection of anatomy and pathology of the injury, an early decision to call for perfusion and cardiothoracic surgery, and prompt blood transfusion were the key factors that allowed for the patient to survive without deficits.

Possible Predictive Factor of Acute Respiratory Distress Syndrome Development After Mild Traumatic Brain Injury: A Single Rural Trauma Center Preliminary Study

Introduction Acute respiratory distress syndrome (ARDS) after mild traumatic brain injury (TBI) can be associated with significant morbidity and mortality. This study aimed to evaluate the potential predictive factors of ARDS development following mild TBI in trauma patients. Methods A retrospective chart review was done for adult trauma patients with mild TBI (GCS 13-15) requiring admission at our center from 2012 to 2020. Linear regression analysis and chi-square test were utilized to identify independent predictors of the association with ARDS in adults with mild TBI.  Results A total of 784 mild TBI patients were admitted during the time of interest; 34 patients developed ARDS during their index hospitalization. Patients who had ARDS were more likely to have acute kidney injury (AKI; p < 0.0001), sepsis (p < 0.01), rib fractures (p < 0.05), use of anticoagulants (p < 0.001), deep vein thrombosis (p < 0.001), transfusion during the first 4four hours upon admission (p = 0.01), intravenous fluid (IVF) resuscitation during the first four hours (p <0.05), the first eight hours (p = 0.01), the first 12 hours (p = 0.03), and intubation upon the admission (p < 0.0001). ARDS associated with mild TBI demonstrated a statistically significant increase in mortality during the index hospitalization (p < 0.0001). Conclusion ARDS after mild TBI can be associated with significant morbidity and mortality. Key risk factors identified include AKI, sepsis, anticoagulant use, deep vein thrombosis (DVT), transfusion in the first four hours, IVF resuscitation in the first four, eight, and 12 hours, and intubation upon admission.

Thrombin immobilized polydopamine-diatom biosilica for effective hemorrhage control

In this study, an efficient composite hemostatic material (DA-diatom-T) was prepared, using a polydopamine layer as a linker to immobilize thrombin on the surface of diatom biosilica. DA-diatom-T retained the porous structure of the diatom with high water absorption capacity, which can absorb 31 times its own weight of water. The thrombin activity of DA-diatom-T was as high as 5.81 U mg-1 that could be maintained at 67% after 30 days at room temperature. DA-diatom-T exhibited non-toxicity to mouse fibroblast cell lines, favorable hemocompatibility and fast procoagulant ability. DA-diatom-T could promote the initiation of the coagulation process and increase platelet activity and blood clot strength to form a physical barrier at the wound. In an in vivo study, DA-diatom-T could significantly reduce the clotting time and reduce the bleeding volume. The above results showed that DA-diatom-T had potential as a new hemostatic material.

Resuscitation of the Traumatically Injured Patient

Trauma is a leading cause of death. Optimal outcomes depend on a coordinated effort. Providers must be prepared to act in an organized and methodical manner. Recognizing and immediately treating causes of shock after trauma offer the best chance of survival to the patient. Incorporating evidence-based knowledge and resuscitation techniques learned from the military, the trauma victim experiencing acute hypovolemia has better outcomes because of advances in the clinical management of blood loss than ever before. Treatment focuses primarily on stopping the bleeding, providing damage control resuscitation, and monitoring and treating the patient for signs of shock. If the patient can be stabilized and avoid the lethal trauma triad, definitive surgical care can be achieved.

Physiology of Human Hemorrhage and Compensation

Hemorrhage is a leading cause of death following traumatic injuries in the United States. Much of the previous work in assessing the physiology and pathophysiology underlying blood loss has focused on descriptive measures of hemodynamic responses such as blood pressure, cardiac output, stroke volume, heart rate, and vascular resistance as indicators of changes in organ perfusion. More recent work has shifted the focus toward understanding mechanisms of compensation for reduced systemic delivery and cellular utilization of oxygen as a more comprehensive approach to understanding the complex physiologic changes that occur following and during blood loss. In this article, we begin with applying dimensional analysis for comparison of animal models, and progress to descriptions of various physiological consequences of hemorrhage. We then introduce the complementary side of compensation by detailing the complexity and integration of various compensatory mechanisms that are activated from the initiation of hemorrhage and serve to maintain adequate vital organ perfusion and hemodynamic stability in the scenario of reduced systemic delivery of oxygen until the onset of hemodynamic decompensation. New data are introduced that challenge legacy concepts related to mechanisms that underlie baroreflex functions and provide novel insights into the measurement of the integrated response of compensation to central hypovolemia known as the compensatory reserve. The impact of demographic and environmental factors on tolerance to hemorrhage is also reviewed. Finally, we describe how understanding the physiology of compensation can be translated to applications for early assessment of the clinical status and accurate triage of hypovolemic and hypotensive patients. © 2021 American Physiological Society. Compr Physiol 11:1531-1574, 2021.

Prehospital Damage Control: The Management of Volume, Temperature… and Bleeding!

Damage control resuscitation should be initiated as soon as possible after a trauma event to avoid metabolic decompensation and high mortality rates. The aim of this article is to assess the position of the Trauma and Emergency Surgery Group (CTE) from Cali, Colombia regarding prehospital care, and to present our experience in the implementation of the “Stop the Bleed” initiative within Latin America. Prehospital care is phase 0 of damage control resuscitation. Prehospital damage control must follow the guidelines proposed by the “Stop the Bleed” initiative. We identified that prehospital personnel have a better perception of hemostatic techniques such as tourniquet use than the hospital providers. The use of tourniquets is recommended as a measure to control bleeding. Fluid management should be initiated using low volume crystalloids, ideally 250 cc boluses, maintaining the principle of permissive hypotension with a systolic blood pressure range between 80- and 90-mm Hg. Hypothermia must be management using warmed blankets or the administration of intravenous fluids warmed prior to infusion. However, these prehospital measures should not delay the transfer time of a patient from the scene to the hospital. To conclude, prehospital damage control measures are the first steps in the control of bleeding and the initiation of hemostatic resuscitation in the traumatically injured patient. Early interventions without increasing the transfer time to a hospital are the keys to increase survival rate of severe trauma patients.

Crystalloids and colloids

Administration of intravenous fluid is like giving drugs, in that they have both beneficial and harmful effects. The composition of intravenous crystalloid and colloid fluids used for resuscitation is described in detail. The use of fluids for intravascular volume replacement is discussed as well as some of the controversies of this in haemorrhagic shock and septic shock.

Managing preoperative anemia: Evolving concepts and strategies for improving patient outcomes

Anemia is the most common hematological disease, and is defined by the World Health Organization as a condition in which the number of red blood cells and consequently oxygen-carrying capacity is insufficient to meet the physiological needs of the body. Anemia can occur throughout the perioperative period and has important clinical consequences. Preoperative anemia is usually regarded as no more than a surrogate marker of a patient's physical status, and it is not always adequately addressed before surgery. Postoperative anemia is a common event and occurs in 80-90% of patients who have undergone major surgery. This manuscript discusses the detection and management of preoperative anemia, the three pillars of patient blood management, perioperative anemia management, and risk stratification for anemia in the surgical setting.