Is the normalisation of blood pressure in bleeding trauma patients harmful?

Hypertension during transfer is associated with poor outcomes in unstable patients with ruptured abdominal aortic aneurysm

OBJECTIVE

Limited data exist for optimal blood pressure (BP) management during transfer of patients with ruptured abdominal aortic aneurysm (rAAA). This study evaluates the effects of hypertension and severe hypotension during interhospital transfers in a cohort of patients with rAAA in hemorrhagic shock.

METHODS

We performed a retrospective, single-institution review of patients with rAAA transferred via air ambulance to a quaternary referral center for repair (2003-2019). Vitals were recorded every 5 minutes in transit. Hypertension was defined as a systolic BP of ≥140 mm Hg. The primary cohort included patients with rAAA with hemorrhagic shock (≥1 episode of a systolic BP of <90 mm Hg) during transfer. The primary analysis compared those who experienced any hypertensive episode to those who did not. A secondary analysis evaluated those with either hypertension or severe hypotension <70 mm Hg. The primary outcome was 30-day mortality.

RESULTS

Detailed BP data were available for 271 patients, of which 125 (46.1%) had evidence of hemorrhagic shock. The mean age was 74.2 ± 9.1 years, 93 (74.4%) were male, and the median total transport time from helicopter dispatch to arrival at the treatment facility was 65 minutes (interquartile range, 46-79 minutes). Among the cohort with shock, 26.4% (n = 33) had at least one episode of hypertension. There were no significant differences in age, sex, comorbidities, AAA repair type, AAA anatomic location, fluid resuscitation volume, blood transfusion volume, or vasopressor administration between the hypertensive and nonhypertensive groups. Patients with hypertension more frequently received prehospital antihypertensives (15% vs 2%; P = .01) and pain medication (64% vs 24%; P < .001), and had longer transit times (36.3 minutes vs 26.0 minutes; P = .006). Episodes of hypertension were associated with significantly increased 30-day mortality on multivariable logistic regression (adjusted odds ratio [aOR], 4.71; 95% confidence interval [CI], 1.54-14.39; P = .007; 59.4% [n = 19] vs 40.2% [n = 37]; P = .01). Severe hypotension (46%; n = 57) was also associated with higher 30-day mortality (aOR, 2.82; 95% CI, 1.27-6.28; P = .01; 60% [n = 34] vs 32% [n = 22]; P = .01). Those with either hypertension or severe hypotension (54%; n = 66) also had an increased odds of mortality (aOR, 2.95; 95% CI, 1.08-8.11; P = .04; 58% [n = 38] vs 31% [n = 18]; P < .01). Level of hypertension, BP fluctuation, and timing of hypertension were not significantly associated with mortality.

CONCLUSIONS

Hypertensive and severely hypotensive episodes during interhospital transfer were independently associated with increased 30-day mortality in patients with rAAA with shock. Hypertension should be avoided in these patients, but permissive hypotension approaches should also maintain systolic BPs above 70 mm Hg whenever possible.

[Guidelines for Non-variceal Upper Gastrointestinal Bleeding]

Non-variceal upper gastrointestinal bleeding (NVUGIB) refers to bleeding that develops in the gastrointestinal tract proximal to the ligament of Treitz. NVUGIB is an important cause for visiting the hospital and is associated with significant morbidity and mortality. Although European and Asian-Pacific guidelines have been published, there has been no previous guidelines regarding management of NVUGIB in Korea. Korea is a country with a high prevalence of Helicobacter pylori infection and patients have easy accessibility to receive endoscopy. Therefore, we believe that guidelines regarding management of NVUGIB are mandatory. The Korean Society of Gastroenterology reviewed recent evidence and recommends practical management guidelines on NVUGIB in Korea.

Patient's performance status should dictate transfusion strategy in nonvariceal acute upper gastrointestinal bleeding (NV-AUGIB): A prospective multicenter cohort study: Transfusion strategy in NV-AUGIB

BACKGROUND

Non-variceal acute UGI bleeding (NV-AUGIB) is a frequent indication for transfusion, but the best hemoglobin threshold and target values for transfusion in relation to the patients' performance status are unknown.

OBJECTIVE

To identify threshold and target hemoglobin levels for transfusion favoring survival of patients with NV-AUGIB stratified by ASA score.

DESIGN

Prospective cohort study.

SETTING

50 hospitals of the Italian National Health Service.

PARTICIPANTS

2758 consecutive patients with NV-AUGIB admitted to 50 Italian hospitals from January 1st, 2014 to December 31st, 2015. Five hemoglobin cut-off values were evaluated.

RESULTS

30-days mortality: overall: 5.4%; ASA 1-2 patients: 2.5%; ASA 3-4 patients: 10.8%. Mortality was higher when hemoglobin at admission was ≤ 7 g/dL in ASA 1-2 patients, and when it was ≤ 8 g/dL in ASA 3-4 patients. The hemoglobin levels after transfusion favouring survival were ≥ 8 g/dL in ASA 1-2, p <0.0001 and 9-10 g/dL in ASA 3-4 patients; p = 0.0002.

CONCLUSIONS

In patients with NV-AUGIB the physical performance status should dictate the transfusion strategy. In ASA 1-2 patients, admission hemoglobin values ≤ 7 g/dL should prompt transfusion, aiming at a target value of 8-9 g/dL; the corresponding figures for ASA 3-4 patients are: admission hemoglobin level ≤ 8 g/dL and target value of 9-10 g/dL.

Guidelines for Nonvariceal Upper Gastrointestinal Bleeding

Nonvariceal upper gastrointestinal bleeding (NVUGIB) refers to bleeding that develops in the gastrointestinal tract proximal to the ligament of Treitz. NVUGIB requires hospitalization and is associated with significant morbidity and mortality. Although European and Asian-Pacific guidelines have been published, there have been no previous guidelines regarding management of NVUGIB in Korea. Korea has a high prevalence of Helicobacter pylori infections, and patients have easy accessibility to endoscopy. Therefore, we believe that guidelines regarding management of NVUGIB in Korea are essential. The Korean Society of Gastroenterology reviewed the recent evidence and recommends practical management guidelines on NVUGIB in Korea.

Superior Survival Outcomes of a Polyethylene Glycol-20k Based Resuscitation Solution in a Preclinical Porcine Model of Lethal Hemorrhagic Shock

OBJECTIVE

To compare early outcomes and 24-hour survival after LVR with the novel polyethylene glycol-20k-based crystalloid (PEG-20k), WB, or hextend in a preclinical model of lethal HS.

BACKGROUND

Posttraumatic HS is a major cause of preventable death. Current resuscitation strategies focus on restoring oxygen-carrying capacity (OCC) and coagulation with blood products. Our lab shows that PEG-20k is an effective non-sanguineous, LVR solution in acute models of HS through mechanisms targeting cell swelling-induced microcirculatory failure.

METHODS

Male pigs underwent splenectomy followed by controlled hemorrhage until lactate reached 7.5-8.5 mmol/L. They were randomized to receive LVR with PEG-20k, WB, or Hextend. Surviving animals were recovered 4 hours post-LVR. Outcomes included 24-hour survival rates, mean arterial pressure, lactate, hemoglobin, and estimated intravascular volume changes.

RESULTS

Twenty-four-hour survival rates were 100%, 16.7%, and 0% in the PEG-20k, WB, and Hextend groups, respectively (P = 0.001). PEG-20k significantly restored mean arterial press, intravascular volume, and capillary perfusion to baseline, compared to other groups. This caused complete lactate clearance despite decreased OCC. Neurological function was normal after next-day recovery in PEG-20k resuscitated pigs.

CONCLUSION

Superior early and 24-hour outcomes were observed with PEG-20k LVR compared to WB and Hextend in a preclinical porcine model of lethal HS, despite decreased OCC from substantial volume-expansion. These findings demonstrate the importance of enhancing microcirculatory perfusion in early resuscitation strategies.

Can prospective systematic reviews of animal studies improve clinical translation?

Systematic reviews are powerful tools with the potential to generate high quality evidence. Their application to animal studies has been instrumental in exposing the poor quality of these studies, as well as a catalyst for improvements in study design, conduct and reporting. It has been suggested that prospective systematic reviews of animal studies (i.e. systematic reviews conducted prior to clinical trials) would allow scrutiny of the preclinical evidence, providing valuable information on safety and efficacy, and helping to determine whether clinical trials should proceed. However, while prospective systematic reviews allow valuable scrutiny of the preclinical animal data, they are not necessarily able to reliably predict the safety and efficacy of an intervention when trialled in humans. Consequently, they may not reliably safeguard humans participating in clinical trials and might potentially result in lost opportunities for beneficial clinical treatments. Furthermore, animal and human studies are often conducted concurrently, which not only makes prospective systematic reviews of animal studies impossible, but suggests that animal studies do not inform human studies in the manner presumed. We suggest that this points to a confused attitude regarding animal studies, whereby tradition demands that they precede human studies but practice indicates that their findings are often ignored. We argue that it is time to assess the relative contributions of animal and human research in order to better understand how clinical knowledge is actually produced.

Controlled hypotension versus normotensive resuscitation strategy for people with ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) is the pathological enlargement of the aorta and can develop in both men and women. Progressive aneurysm enlargement can lead to rupture. The rupture of an AAA is frequently fatal and accounts for the death from haemorrhagic shock of at least 45 people per 100,000 population. The outcome of people with ruptured AAA varies among countries and healthcare systems, with mortality ranging from 53% to 90%. Definitive treatment for ruptured AAA includes open surgery or endovascular repair. The management of haemorrhagic shock is crucial for the person's outcome and aims to restore organ perfusion and systolic blood pressure above 100 mmHg through immediate and aggressive fluid replacement. This rapid fluid replacement is known as the normotensive resuscitation strategy. However, evidence suggests that infusing large volumes of cold fluid causes dilutional and hypothermic coagulopathy. The association of these factors may exacerbate bleeding, resulting in a 'lethal triad' of hypothermia, acidaemia, and coagulopathy. An alternative to the normotensive resuscitation strategy is the controlled (permissive) hypotension resuscitation strategy, with a target systolic blood pressure of 50 mmHg to 100 mmHg. The principle of controlled or hypotensive resuscitation has been used in some management protocols for endovascular repair of ruptured AAA. It may be beneficial in preventing blood loss by avoiding the clot disruption caused by the rapid increase in systolic blood pressure; avoiding dilution of clotting factors, platelets and fibrinogen; and by avoiding the temperature decrease that inhibits enzyme activity involved in platelet and clotting factor function. This is an update of a review first published in 2016.

OBJECTIVES

To compare the effects of controlled (permissive) hypotension resuscitation and normotensive resuscitation strategies for people with ruptured AAA.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Specialised Register (August 2017), the Cochrane Register of Studies (CENTRAL (2017, Issue 7)) and EMBASE (August 2017). The Cochrane Vascular Information Specialist also searched clinical trials databases (August 2017) for details of ongoing or unpublished studies.

SELECTION CRITERIA

We sought all published and unpublished randomised controlled trial (RCTs) that compared controlled hypotension and normotensive resuscitation strategies for the management of shock in patients with ruptured abdominal aortic aneurysms.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed identified studies for potential inclusion in the review. We used standard methodological procedures in accordance with the Cochrane Handbook for Systematic Review of Interventions.

MAIN RESULTS

We identified no RCTs that met the inclusion criteria.

AUTHORS' CONCLUSIONS

We found no RCTs that compared controlled hypotension and normotensive resuscitation strategies in the management of haemorrhagic shock in patients with ruptured abdominal aortic aneurysm that assessed mortality, presence of coagulopathy, intensive care unit length of stay, and the presence of myocardial infarct and renal failure. High quality studies that evaluate the best strategy for managing haemorrhagic shock in ruptured abdominal aortic aneurysms are required.

The Evolution of Damage Control in Concept and Practice

Damage control surgery (DCS) began as an adjunct approach to hemorrhage control, seeking to facilitate the body's innate clotting ability when direct repair or ligation was impossible, but it has since become a valuable instrument for a broader collection of critically ill surgical patients in whom metabolic dysfunction is the more immediate threat to life than imminent exsanguination. Modern damage control is a strategy that combines the principles of DCS with those of damage control resuscitation. When used correctly, damage control may improve survival in previously unsalvageable patients; when used incorrectly, it can subject patients to imprudent risk and contribute to morbidity. This review discusses the evolution of damage control in both concept and practice, summarizing available literature and experience to guide patient selection, medical decision-making, and strategy implementation throughout the preoperative, intraoperative, and early postoperative periods.

Prevention and management of gastroesophageal varices

Bleeding from gastroesophageal varices is a serious complication in patients with liver cirrhosis and portal hypertension. Although there has been significance improvement in the prognosis of variceal bleeding with advancement in diagnostic and therapeutic modalities for its management, mortality rate still remains high. Therefore, appropriate prevention and rapid, effective management of bleeding from gastroesophageal varices is very important. Recently, various studies about management of gastoesophageal varices, including prevention of development and aggravation of varices, prevention of first variceal bleeding, management of acute variceal bleeding, and prevention of variceal rebleeding, have been published. The present article reviews published articles and practice guidelines to present the most optimal management of patients with gastroesophageal varices.

Emergency Medical team: an Entrapped Patient

Motor vehicle collision is one leading cause of morbidity and mortality. Victims may be trapped in the deformed vehicles. Emergency medical team may be summoned to help in the extrication process. The principles of resuscitation in the pre-hospital phase are the same as in the in-hospital phase, but clinicians would face greater impediments to success in the former situation. We present a case of motor vehicle collision in which an emergency medical team was called to assist in the extrication of an entrapped patient. The principles of pre-hospital trauma care are discussed.

Prehospital hypertonic fluid resuscitation for trauma patients: A systematic review and meta-analysis

BACKGROUND

Prehospital assessment of a patient's circulation status and appropriate resuscitation with intravenous fluids plays a critical role in patients with obvious hemorrhage or systolic blood pressure below 90 mm Hg.

OBJECTIVES

We assessed the efficacy and safety of prehospital administration of crystalloids or colloids to improve the survival rate of trauma patients with acceptable safety profile.

DATA SOURCES

We searched SCOPUS, Embase, TRIP database, Cochrane Central Register of Controlled Trials, Ovid MEDLINE, and PubMed as per search protocol from January 1, 1900 to February 12, 2015.

STUDY ELIGIBILITY CRITERIA

All randomized controlled trials were considered.

PARTICIPANTS AND INTERVENTIONS

All patients had penetrating or blunt trauma, excluding traumatic brain or thermal injuries. At least one of the comparators should be a crystalloid or colloid.

STUDY APPRAISAL AND SYNTHESIS METHODS

Detailed search strategy was developed and utilized. Duplicates were removed from the search results. We, the co-first authors (C.d.C. and F.G.), independently reviewed the article titles and abstracts to assess eligibility. Eligible articles were downloaded for full text review to determine inclusion in the review and analysis. We (C.d.C. and F.G.) performed a methodological quality assessment of each included article. The primary outcome was mortality. The secondary outcomes included adverse events, infections, multiple organ dysfunction score, and length of stay at the hospital. Heterogeneity was measured by I value. An I value greater than 50% was considered to be substantial heterogeneity. Fixed effect analysis and random effect analysis were performed when needed.

RESULTS

A total of nine trials (3,490 patients) were included in the systematic review, and six trials were included in meta-analyses. There were no significant differences between hypertonic saline with dextran and lactated Ringer's solution in 1 day using two studies (2.91; 95% CI, 0.58-14.54; p = 0.19) and 28- to 30-day survival rates using another two studies (1.47; 95% CI, 0.30-7.18; p = 0.63). Adding dextran to hypertonic saline did not increase the survival rate (0.94; 95% CI, 0.65-1.34; p = 0.71). Overall, complications were comparable between all groups.

LIMITATIONS

The quality of some of the included studies is not optimal.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

There is no beneficial effect of hypertonic saline with or without dextran in general traumatic patients. Further trials to evaluate its benefit in patients with penetrating trauma requiring surgery are warranted.

LEVEL OF EVIDENCE

Systematic review and meta-analysis, level I.

Typical vasovagal syncope as a "defense mechanism" for the heart by contrasting sympathetic overactivity

Many observations suggest that typical (emotional or orthostatic) vasovagal syncope (VVS) is not a disease, but rather a manifestation of a non-pathological trait. Some authors have hypothesized this type of syncope as a "defense mechanism" for the organism and a few theories have been postulated. Under the human violent conflicts theory, the VVS evolved during the Paleolithic era only in the human lineage. In this evolutionary period, a predominant cause of death was wounding by a sharp object. This theory could explain the occurrence of emotional VVS, but not of the orthostatic one. The clot production theory suggests that the vasovagal reflex is a defense mechanism against hemorrhage in mammals. This theory could explain orthostatic VVS, but not emotional VVS. The brain self-preservation theory is mainly based on the observation that during tilt testing a decrease in cerebral blood flow often precedes the drop in blood pressure and heart rate. The faint causes the body to take on a gravitationally neutral position, and thereby provides a better chance of restoring brain blood supply. However, a decrease in cerebral blood flow has not been demonstrated during negative emotions, which trigger emotional VVS. Under the heart defense theory, the vasovagal reflex seems to be a protective mechanism against sympathetic overactivity and the heart is the most vulnerable organ during this condition. This appears to be the only unifying theory able to explain the occurrence of the vasovagal reflex and its associated selective advantage, during both orthostatic and emotional stress.

Trauma and critical care III: chest trauma

Patients requiring intensive care for chest trauma are often severely injured and may have suffered trauma elsewhere. The single largest cause of significant blunt chest trauma is road traffic accidents (RTAs). RTAs account for 70-80% of such injuries. Falls and acts of violence are other causative mechanisms. Blast injuries can also result in significant blunt thoracic trauma. Penetrating chest trauma comprises a broad spectrum of injuries and severity. Particular challenges occur in patients with associated polytrauma, as well as those with a combination of blunt and penetrating chest trauma. Chest injury is the most important injury in polytrauma patients with reported incidences of 45-65% and an associated mortality of up to 60%. The treatment of these patients can be prolonged and the initial injury may become of secondary importance to the effects of systemic inflammatory response syndrome, acute lung injury (ALI), nosocomial infection and intercurrent multiorgan dysfunction syndrome (MODS). Multiply-injured patients with thoracic injuries require significantly longer periods of mechanical ventilation and longer intensive care unit lengths of stay compared with nonthoracic injury trauma patients. The use of a variety of therapeutic interventions may have to be considered during management of the disease process.

Pharmacologic agents for acute hemodynamic instability: recent advances in the management of perioperative shock- a systematic review

Despite the growing body of evidence evaluating the efficacy of vasoactive agents in the management of hemodynamic instability and circulatory shock, it appears no agent is superior. This is becoming increasingly accepted as current guidelines are moving away from detailed algorithms for the management of shock, and instead succinctly state that vasoactive agents should be individualized and guided by invasive hemodynamic monitoring. This extends to the perioperative period, where vasoactive agent selection and use may still be left to the discretion of the treating physician with a goal-directed approach, consisting of close hemodynamic monitoring and administration of the lowest effective dose to achieve the hemodynamic goals. Successful therapy depends on the ability to rapidly diagnose the etiology of circulatory shock and thoroughly understand its pathophysiology as well as the pharmacology of vasoactive agents. This review focuses on the physiology and resuscitation goals in perioperative shock, as well as the pharmacology and recent advances in vasoactive agent use in its management.

Liver trauma

Management of blunt or penetrating injury to the liver remains a significant challenge to trauma surgeons. Liver injury remains common in both blunt and penetrating trauma of the abdomen. Unstable patients require immediate laparotomy. Selective patients can be managed without surgery and with careful monitoring. There has been a recent resurgence in the role of temporary packing in the management of liver trauma. Other commonly used techniques are resectional debribement and suture ligation of bleeding vessels. Complications include haemorrhage, bile leak and sepsis. Mortality is mainly due to damage to major hepatic blood vessels or other associated non-hepatic injuries. With improved understanding of the major causes of death from hepatic injury, improved resuscitation and intensive care, mortality has fallen below 10%.

The clinical effectiveness of pre-hospital intravenous fluid replacement in trauma patients without head injury: a systematic review

Traditionally, the management of bleeding trauma patients has included early rapid fluid replacement on scene. However, evidence shows that a delay to definitive treatment (control of bleeding) may be harmful and UK policy advocates minimal delay on scene with intravenous fluids being administered in transit to hospitals. This paper systematically reviews the evidence for administering fluids in pre-hospital trauma patients with no head injury. Randomized controlled trials comparing immediate and delayed fluid replacement were sought using formal search strategies. Study selection, quality assessment and data extraction were performed independently by two reviewers using pre-defined criteria. We found no evidence to suggest that pre-hospital fluid administration is beneficial. There is some evidence that it may be harmful and that patients do comparatively well when fluids are withheld. However, this evidence is not conclusive, particularly for blunt trauma, and is not sufficient to disprove current UK policy, which recommends hypotensive resuscitation.

Controlled hypotension versus normotensive resuscitation strategy for people with ruptured abdominal aortic aneurysm

BACKGROUND

An abdominal aortic aneurysm (AAA) is the pathological enlargement of the aorta and can develop in both men and women. Progressive aneurysm enlargement can lead to rupture. The rupture of an AAA is frequently fatal and accounts for the death from haemorrhagic shock of at least 45 people per 100,000 population. The outcome of people with ruptured AAA varies among countries and healthcare systems, with mortality ranging from 53% to 90%. Definitive treatment for ruptured AAA includes open surgery or endovascular repair. The management of haemorrhagic shock is crucial for the person's outcome and aims to restore organ perfusion and systolic blood pressure above 100 mm Hg through immediate and aggressive fluid replacement. This rapid fluid replacement is known as the normotensive resuscitation strategy. However, evidence suggests that infusing large volumes of cold fluid causes dilutional and hypothermic coagulopathy. The association of these factors may exacerbate bleeding, resulting in a 'lethal triad' of hypothermia, acidaemia, and coagulopathy. An alternative to the normotensive resuscitation strategy is the controlled (permissive) hypotension resuscitation strategy, with a target systolic blood pressure of 50 to 100 mm Hg. The principle of controlled or hypotensive resuscitation has been used in some management protocols for endovascular repair of ruptured AAA. It may be beneficial in preventing blood loss by avoiding the clot disruption caused by the rapid increase in systolic blood pressure; avoiding dilution of clotting factors, platelets and fibrinogen; and by avoiding the temperature decrease that inhibits enzyme activity involved in platelet and clotting factor function.

OBJECTIVES

To compare the effects of controlled (permissive) hypotension resuscitation and normotensive resuscitation strategies for people with ruptured AAA.

SEARCH METHODS

The Cochrane Vascular Information Specialist searched the Specialised Register (April 2016) and the Cochrane Register of Studies (CENTRAL (2016, Issue 3)). Clinical trials databases were searched (April 2016) for details of ongoing or unpublished studies.

SELECTION CRITERIA

We sought all published and unpublished randomised controlled trial (RCTs) that compared controlled hypotension and normotensive resuscitation strategies for the management of shock in patients with ruptured abdominal aortic aneurysms.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed identified studies for potential inclusion in the review. We used standard methodological procedures in accordance with the Cochrane Handbook for Systematic Review of Interventions.

MAIN RESULTS

We identified no RCTs that met the inclusion criteria.

AUTHORS' CONCLUSIONS

We found no RCTs that compared controlled hypotension and normotensive resuscitation strategies in the management of haemorrhagic shock in patients with ruptured abdominal aortic aneurysm that assessed mortality, presence of coagulopathy, intensive care unit length of stay, and the presence of myocardial infarct and renal failure. High quality studies that evaluate the best strategy for managing haemorrhagic shock in ruptured abdominal aortic aneurysms are required.

Upper gastrointestinal haemorrhage: an update

Upper gastrointestinal (GI) haemorrhage is a common cause for admission to hospital and is associated with a mortality of around 10%. Prompt assessment and resuscitation are vital, as are risk stratification of the severity of bleeding, early involvement of the multidisciplinary team and timely access to endoscopy, preferably within 24 h. The majority of bleeds are due to peptic ulcers for which Helicobacter pylori and non-steroidal anti-inflammatory agents are the main risk factors. Although proton pump inhibitors (PPIs) are widely used before endoscopy, this is controversial. Pre-endoscopic risk stratification with the Glasgow Blatchford score is recommended as is the use of the Rockall score postendoscopy. Endoscopic therapy, with at least two haemostatic modalities, remains the mainstay of treating high-risk lesions and reduces rebleeding rates and mortality. High-dose PPI therapy after endoscopic haemostasis also reduces rebleeding rates and mortality. Variceal oesophageal haemorrhage is associated with a higher rebleeding rate and risk of death. Antibiotics and vasopressin analogues are advised in suspected variceal bleeding; however, endoscopic variceal band ligation remains the haemostatic treatment of choice. Balloon tamponade remains useful in the presence of torrential variceal haemorrhage or when endoscopy fails to secure haemostasis, and can be a bridge to further endoscopic attempts or placement of a transjugular intrahepatic portosystemic shunt. This review aims to provide an update on the latest evidence-based recommendations for the management of acute upper GI haemorrhage.

Preferential effects of low volume versus high volume replacement with crystalloid fluid in a hemorrhagic shock model in pigs

Background

Fluid resuscitation is a core stone of hemorrhagic shock therapy, and crystalloid fluids seem to be associated with lower mortality compared to colloids. However, as redistribution starts within minutes, it has been suggested to replace blood loss with a minimum of a three-fold amount of crystalloids. The hypothesis was that in comparison to high volume (HV), a lower crystalloid volume (LV) achieves a favorable coagulation profile and exerts sufficient haemodynamics in the acute phase of resuscitation.

Methods

In 24 anaesthetized pigs, controlled arterial blood loss of 50 % of the estimated blood volume was either (n = 12) replaced with a LV (one-fold) or a HV (three-fold) volume of a balanced, acetated crystalloid solution at room temperature. Hemodynamic parameters, dilution effects and coagulation profile by standard coagulation tests and thromboelastometry at baseline and after resuscitation were determined in both groups.

Results

LV resuscitation increased MAP significantly less compared to the HV, 61 ± 7 vs. 82 ± 14 mmHg (p < 0.001) respectively, with no difference between lactate and base excess between groups. Haematocrit after fluid replacement was 0.20 vs. 0.16 (LV vs. HV, p < 0.001), suggesting a grade of blood dilution of 32 vs. 42 % (p < 0.001) compared to baseline values. Compared to LV, HV resulted in decreased core temperature (37.5 ± 0.2 vs. 36.0 ± 0.6 °C, p < 0.001), lower platelet count (318 ± 77 vs. 231 ± 53 K/μL, p < 0.01) and lower plasma fibrinogen levels (205 ± 19 vs. 168 ± 24 mg/dL, p < 0.001). Thromboelastometric measurements showed a significant impairment on viscoelastic clot properties following HV group. While prothrombin time index decreased significantly more in the HV group, activated partial thromboplastin time did not differ between both groups. HV did not result in hyperchloraemic acidosis.

Discussion

Coagulation parameters represented by plasma fibrinogen and ROTEM parameters were also less impaired with LV. With regrad to hematocrit, 60 % of LV remained intracascular , while in HV only 30 % remained in circulation within the first hour of administration. In the acute setting of 50 % controlled blood loss, a one fold LV crystalloid replacement strategy is sufficient to adequately raise blood pressure up to a mean arterial pressure >50 mm Hg. The concept of damage control resuscitation (DCR) with permissive hypotension may be better met by using LV as compared to a three fold HV resuscitation strategy.

Conclusion

High volume administration of an acetated balanced crystalloid does not lead to hyperchloraemic acidosis, but may negatively influence clinical parameters, such as higher blood pressure, lower body temperature and impaired coagulation parameters, which could potentially increase bleeding after trauma. Replacement of acute blood loss with just an equal amount of an acetated balanced crystalloid appears to be the preferential treatment strategy in the acute phase after controlled bleeding.

Vasovagal Syncope As A Manifestation Of An Evolutionary Selected Trait

Some observations suggest that typical (emotional or orthostatic) vasovagal syncope (VVS) is not a disease, but rather a manifestation of a non-pathological trait. We conducted an extensive bibliographic research on the vasovagal reactions in animals, including humans, in order to investigate the possible factors that may explain the origin and evolution of VVS. We found two processes which appear relevant for the investigation of VVS evolution: fear/threat bradycardia (alarm bradycardia) in animals, mainly during tonic immobility and vasovagal reflex during hemorrhagic shock (thoracic hypovolemia) both in animals and humans. The available data suggest that VVS in humans, alarm bradycardia in animals and the vasovagal reflex during hemorrhagic shock share the same physiological mechanisms and that is indicative of a common evolutionary root. However, during the vasovagal reflex loss of consciousness occurs in humans, but it is absent (or extremely rare) in animals. That can be explained as a by-product due to the erect position and the large brain evolved in our species. If the vasovagal reflex persisted for millions of years along the vertebrates evolutionary history, we can reasonably assume that it has a function and it is not harmful. It could be neutral or beneficial, but the available data suggest it is beneficial; likely, it evolved as an advantageous response to stressful and possibly dangerous heart conditions. Emotional or orthostatic vasovagal reflex is preceded by enhanced sympathetic activity, which is harmful and possibly dangerous. The transient inhibition of the sympathetic system, together with activation of the vagal tone , characterizes VVS. The consequent slowing of the heart rate induced by the vasovagal reflex may constitute a beneficial break of the cardiac pump, thereby reducing myocardial oxygen consumption. We suggest that typical VVS should be regarded as a selected response, which probably evolved in the ancient past as a defense mechanism of the organism within some ancestral group(s) of vertebrates.

Target blood pressure for hypotensive resuscitation

BACKGROUND

Good outcomes have resulted from hypotensive resuscitation of hemorrhagic shock patients. We hypothesized that mean arterial pressure (MAP) 60mmHg is the target blood pressure for hypotensive resuscitation during uncontrolled hemorrhagic shock in trauma.

METHODS

To determine the effective target MAP for hypotensive resuscitation during uncontrolled hemorrhagic shock, we randomly assigned 80 rats to one of 8 treatment groups (n=10 for each group). We then observed the effects of different target MAPs (control, 40, 50, 60, 70, 80, 90mmHg, and sham) on fluid resuscitation of uncontrolled hemorrhagic shock. Blood pressure, serum lactate, hematocrit, fluid therapy, blood loss, and plasma cytokine levels were measured at 0, 30, 90, 120, 180, 240, 300min after the start of the surgical procedure.

RESULTS

A target MAP of 90, 80 and 70mmHg had increased blood loss and decreased hematocrit and IL-6 and TNF-α production. A target MAP of 60, 50 and 40mmHg had lower blood loss, good hematocrit, higher IL-6 and TNF-α production, and decreased animal survival. Only target MAPs of 40 and 50 had and decreased animal survival. The differences in blood loss, hematocrit, lactate, post-resuscitation MAP, survival, IL-6, IL-10, and TNF-α production between rats with a target MAP of 60mmHg and those with a target MAP of 70mmHg were not significant. The amount of fluid therapy in the BP 60 groups was less than in the BP 70 groups (P<0.001).

CONCLUSION

A MAP of 60mmHg should be considered for evaluation in human studies as a target for hypotensive resuscitation.

Transfusion strategies for acute upper gastrointestinal bleeding

BACKGROUND

The hemoglobin threshold for transfusion of red cells in patients with acute gastrointestinal bleeding is controversial. We compared the efficacy and safety of a restrictive transfusion strategy with those of a liberal transfusion strategy.

METHODS

We enrolled 921 patients with severe acute upper gastrointestinal bleeding and randomly assigned 461 of them to a restrictive strategy (transfusion when the hemoglobin level fell below 7 g per deciliter) and 460 to a liberal strategy (transfusion when the hemoglobin fell below 9 g per deciliter). Randomization was stratified according to the presence or absence of liver cirrhosis.

RESULTS

A total of 225 patients assigned to the restrictive strategy (51%), as compared with 61 assigned to the liberal strategy (14%), did not receive transfusions (P<0.001) [corrected].The probability of survival at 6 weeks was higher in the restrictive-strategy group than in the liberal-strategy group (95% vs. 91%; hazard ratio for death with restrictive strategy, 0.55; 95% confidence interval [CI], 0.33 to 0.92; P=0.02). Further bleeding occurred in 10% of the patients in the restrictive-strategy group as compared with 16% of the patients in the liberal-strategy group (P=0.01), and adverse events occurred in 40% as compared with 48% (P=0.02). The probability of survival was slightly higher with the restrictive strategy than with the liberal strategy in the subgroup of patients who had bleeding associated with a peptic ulcer (hazard ratio, 0.70; 95% CI, 0.26 to 1.25) and was significantly higher in the subgroup of patients with cirrhosis and Child-Pugh class A or B disease (hazard ratio, 0.30; 95% CI, 0.11 to 0.85), but not in those with cirrhosis and Child-Pugh class C disease (hazard ratio, 1.04; 95% CI, 0.45 to 2.37). Within the first 5 days, the portal-pressure gradient increased significantly in patients assigned to the liberal strategy (P=0.03) but not in those assigned to the restrictive strategy.

CONCLUSIONS

As compared with a liberal transfusion strategy, a restrictive strategy significantly improved outcomes in patients with acute upper gastrointestinal bleeding. (Funded by Fundació Investigació Sant Pau; ClinicalTrials.gov number, NCT00414713.).

The effect of fibrinogen concentrate and factor XIII on thromboelastometry in 33% diluted blood with albumin, gelatine, hydroxyethyl starch or saline in vitro

BACKGROUND

Fluid replacement results in dilutional coagulopathy. We investigated the potential role of fibrinogen, factor XIII and a combination of both to reverse dilutional coagulopathy, assessed by thromboelastometry (ROTEM(®)).

MATERIAL AND METHODS

Blood samples from healthy volunteers were analysed undiluted and after 33% dilution in vitro with albumin, gelatine, 130/0.4 hydroxyethyl starch or saline. Diluted samples were incubated with fibrinogen (3 g/70 kg bodyweight equivalent), factor XIII (10,000 IU/70 kg bodyweight equivalent), or a combination of both. Measurements were performed using an extrinsic activated assay (EXTEM(®)) and a functional fibrin polymerisation test (FIBTEM(®)).

RESULTS

Compared with baseline, EXTEM clotting time increased with hydroxyethyl starch, exceeding the upper limit of the reference value. Albumin prolonged clotting time within normal limits. Gelatine did not change clotting time, and saline reduced clotting time. Clot formation time increased in colloids only. Maximum clot firmness of both EXTEM and FIBTEM decreased with all fluids, but was less pronounced in saline. Incubation with fibrinogen had no effect on EXTEM maximum clot firmness but improved FIBTEM maximum clot firmness in saline (P <0.001) and albumin (P <0.05), but not gelatine and hydroxyethyl starch). Factor XIII had no effect on any EXTEM and FIBTEM maximum clot firmness results. Fibrinogen and factor XIII combined did not improve EXTEM maximum clot firmness. Fibrinogen and factor XIII did not change FIBTEM maximum clot firmness in hydroxyethyl starch but improved FIBTEM maximum clot firmness in albumin (P <0.001), gelatine (P <0.01) and saline (P <0.001).

DISCUSSION

ROTEM parameters in dilutional coagulopathy in vitro cannot be improved with factor XIII alone in any tested diluent. The combination of fibrinogen and factor XIII is highly effective in raising FIBTEM maximum clot firmness after dilution with albumin, gelatine and saline back to normal values, but is ineffective in 130/0.4 hydroxyethyl starch.

Permissive hypotension does not reduce regional organ perfusion compared to normotensive resuscitation: animal study with fluorescent microspheres

Introduction

The objective of this study was to investigate regional organ perfusion acutely following uncontrolled hemorrhage in an animal model that simulates a penetrating vascular injury and accounts for prehospital times in urban trauma. We set forth to determine if hypotensive resuscitation (permissive hypotension) would result in equivalent organ perfusion compared to normotensive resuscitation.

Methods

Twenty four (n=24) male rats randomized to 4 groups: Sham, No Fluid (NF), Permissive Hypotension (PH) (60% of baseline mean arterial pressure - MAP), Normotensive Resuscitation (NBP). Uncontrolled hemorrhage caused by a standardised injury to the abdominal aorta; MAP was monitored continuously and lactated Ringer’s was infused. Fluorimeter readings of regional blood flow of the brain, heart, lung, kidney, liver, and bowel were obtained at baseline and 85 minutes after hemorrhage, as well as, cardiac output, lactic acid, and laboratory tests; intra-abdominal blood loss was assessed. Analysis of variance was used for comparison.

Results

Intra-abdominal blood loss was higher in NBP group, as well as, lower hematocrit and hemoglobin levels. No statistical differences in perfusion of any organ between PH and NBP groups. No statistical difference in cardiac output between PH and NBP groups, as well as, in lactic acid levels between PH and NBP. NF group had significantly higher lactic acidosis and had significantly lower organ perfusion.

Conclusions

Hypotensive resuscitation causes less intra-abdominal bleeding than normotensive resuscitation and concurrently maintains equivalent organ perfusion. No fluid resuscitation reduces intra-abdominal bleeding but also significantly reduces organ perfusion.

Evaluation of the Prehospital Management of Road Traffic Fatalities in Victoria, Australia

Introduction:

This study was undertaken to identify prehospital system and management deficiencies and preventable deaths between 01 January 1997 and 31 December 1998 in 243 consecutive Victorian road crash victims with fatal outcomes.

Methods:

The complete prehospital and hospital records, the deposition to the coroner, and autopsy findings were evaluated by computer analysis and peer group review with multidisciplinary discussion.

Results:

One-hundred eighty-seven (77%) patients had prehospital errors or inadequacies, of which 135 (67%) contributed to death. Three-hundred ninety-four (67%) related to management and 130 (22%) to system deficiencies. Technique errors, diagnosis delays, and errors relatively were infrequent. One of 24 deaths at the crash scene or en route to hospital was considered to be preventable and two potentially preventable.

Conclusion:

The high prevalence of prehospital deficiencies has been addressed by a Ministerial Task Force on Trauma and Emergency Services and followed by the introduction of a new trauma care system in Victoria.

The clinical effectiveness of permissive hypotension in blunt abdominal trauma with hemorrhagic shock but without head or spine injuries or burns: a systematic review

Background

Trauma is a major cause of death and disability. The current trend in trauma management is the rapid administration of fluid as per the Advanced Trauma Life Support guidelines, although there is no evidence to support this and even some to suggest it might be harmful. Some guidelines, protocols, and recommendations have been established for the use of permissive hypotension although there is reluctance concerning its application in blunt injuries.

Objectives

The aim of this review is to determine whether there is evidence of the use of permissive hypotension in the management of hemorrhagic shock in blunt trauma patients. This review also aims to search for any reason for the reluctance to apply permissive hypotension in blunt injuries.

Methods

This systematic review has followed the steps recommended in the Cochrane Handbook for Systematic Reviews of Interventions. It is also being reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement and checklist. Database searches of MEDLINE, EMBASE, the Centre for Reviews and Dissemination databases and the Cochrane Library were made for eligible studies as well as journal searches. Inclusion criteria included systematic reviews that have similar primary questions to this review and randomized controlled trials where patients with blunt torso injuries and hemorrhagic shock were not excluded. Rapid or early fluid administration was compared with controlled or delayed fluid resuscitation and a significant outcome was obtained.

Results

No systematic reviews attempting to answer similar questions were found. Two randomized controlled trials with mixed types of injuries in the included patients found no significant difference between the groups used in each study. Data concerning the question of this review was sought after these papers were appraised.

Conclusion

The limited available data are not conclusive. However, the supportive theoretical concept and laboratory evidence do not show any reason for treating blunt injuries differently from other traumatic injuries. Moreover, permissive hypotension is being used for some nontraumatic causes of hemorrhagic shock and in theater. Therefore, this should encourage interested researchers to continue clinical work in this important field.

Severe traumatic brain injury: consequences of early adverse events

BACKGROUND

Several factors associated with an unfavourable outcome after severe traumatic brain injury (TBI) have been described: prolonged pre-hospital time, secondary referral to a level 1 trauma centre, the occurrence of secondary insults such as hypoxia, hypotension or low end-tidal carbon dioxide (ETCO(2)). To determine whether adverse events were linked to outcome, patients with severe TBI were studied before arrival at a level 1 trauma centre.

METHODS

Prospective, observational study design. Patients with severe TBI (n = 48), admitted to Umeå University Hospital between January 2002 to December 2005 were included. All medical records from the site of the accident to arrival at the level 1 trauma centre were collected and evaluated.

RESULTS

A pre-hospital time of >60 min, secondary referral to a level 1 trauma centre, documented hypoxia (oxygen saturation <95%), hypotension (systolic blood pressure <90 mmHg), hyperventilation (ETCO(2) <4.5 kPa) or tachycardia (heart rate >100 beats/min) at any time before arrival at a level 1 trauma centre were not significantly related to an unfavourable outcome (Glasgow Outcome Scale 1-3).

CONCLUSION

Early adverse events before arrival at a level 1 trauma centre were without significance for outcome after severe TBI in the trauma system studied.

Randomized controlled trials affecting polytrauma care

Trauma remains the leading cause of death in the world in patients under 45 years of age. The evaluation, resuscitation, and appropriate management of polytraumatized patients are paramount to successful outcomes. The advance of evidence-based medicine has had a powerful and positive impact on trauma care, even though the nature of many traumatic injuries lends itself poorly to study in a randomized fashion. During the initial management of bleeding patients, hypotensive resuscitation prior to surgical control has found strong support in the literature, and its use has been adopted by many surgeons. Head injury is the most common cause of traumatic death, and while high-level evidence is limited, adherence to management guidelines is associated with improved outcomes. For abdominal trauma, the concept of damage control surgery, while popular, has never been put to the test in a randomized controlled trial. Numerous randomized trials in the field of critical care have affected the management of severely injured patients, including intensive insulin therapy and low tidal volume ventilation in patients with compromised respiratory function. Finally, a multidisciplinary approach to trauma care in designated trauma centers allows for improved outcomes in polytraumatized patients.

Surgical intensive care unit--the trauma surgery perspective

PURPOSE

This review addresses and summarizes the key issues and unique specific intensive care treatment of adult patients from the trauma surgery perspective.

MATERIALS AND METHODS

The cornerstones of successful surgical intensive care management are fluid resuscitation, transfusion protocol and extracorporeal organ replacement therapies. The injury-type specific complications and unique pathophysiologic regulatory mechanisms of the traumatized patients influencing the critical care treatment are discussed.

CONCLUSIONS

Furthermore, the fundamental knowledge of the injury severity, understanding of the trauma mechanism, surgical treatment strategies and specific techniques of surgical intensive care are pointed out as essentials for a successful intensive care therapy.

Preventing cardiac arrest during hemorrhagic shock with vasopressin

The optimal strategy of stabilizing hemodynamic function in uncontrolled traumatic hemorrhagic shock states is unclear. Although fluid replacement is established in controlled hemorrhagic shock, its use in uncontrolled hemorrhagic shock is controversial, because it may worsen bleeding. In the refractory phase of severe hemorrhagic shock, arginine vasopressin has been shown to be beneficial in selected cases due to an increase in arterial blood pressure, shift of blood away from a subdiaphragmatic bleeding site toward the heart and brain, and decrease in fluid-resuscitation requirements. Especially in patients with severe traumatic brain injury, rapid stabilization of cardiocirculatory function is essential to ensure adequate brain perfusion, thus, to prevent neurologic damage and to improve outcome. In addition, despite wide distribution of highly developed and professional emergency medical systems in western industrialized countries, survival chances of patients with uncontrolled traumatic hemorrhagic shock in the preclinical setting are still poor.

Permissive hypotension and desmopressin enhance clot formation

BACKGROUND

Experimental studies of uncontrolled hemorrhage demonstrated that permissive hypotension (PH) reduces blood loss, but its effect on clot formation remains unexplored. Desmopressin (DDAVP) enhances platelet adhesion promoting stronger clots. We hypothesized PH and DDAVP have additive effects and reduce bleeding in uncontrolled hemorrhage.

METHODS

Rabbits (n = 42) randomized as follows: sham; normal blood pressure (NBP) resuscitation; PH resuscitation-60% baseline mean arterial pressure; NBP plus DDAVP 1 hour before (DDAVP NBP) or 15 minutes after beginning of shock (DDAVP T1 NBP); and PH plus DDAVP 1 hour before (DDAVP PH) or 15 minutes after beginning of shock (DDAVP T1 PH). Fluid resuscitation started 15 minutes after aortic injury and ended at 85 minutes. Intraabdominal blood loss was calculated, aortic clot sent for electron microscopy. Activated partial thromboplastin time, platelet count, thromboelastometry, arterial blood gases, and complete blood count were performed at baseline and 85 minutes. Analysis of variance was used for comparison.

RESULTS

NBP received more fluid volume and had greater intraabdominal blood loss. DDAVP, when administered preshock, significantly reduced blood loss in NBP and fluid requirement when given postshock. Platelets, arterial blood gas, complete blood count, and activated partial thromboplastin time were similar at 85 minutes. NBP delayed clot formation and worsened thrombodynamic potential on thromboelastometry, whereas PH and DDAVP improved. Electron microscopy showed lack of fibrin on NBP clots, whereas DDAVP and PH clots displayed exuberant fibrin/platelet aggregates. DDAVP NBP presented intermediate clots.

CONCLUSION

PH reduced bleeding and improved hemostasis compared with normotensive resuscitation. DDAVP given preshock exerted similar effects with normotensive resuscitation.

Vasopressin in Hemorrhagic Shock: Review Article

Trauma with resultant hypovolemic shock remains both prevalent and difficult to treat. Standard strategies using volume resuscitation and catecholamine support have historically yielded poor results. Vasopressin has emerged as a possible pharmacologic adjunct, particularly in patients with shock refractory to the administration of fluids and catecholamines. Much of the data regarding vasopressin is extrapolated from its usefulness in cases of nonhypovolemic human shock, which are supported by convincing animal studies. It is true that humans show a deficiency in vasopressin minutes after significant hemorrhage that can respond to administration of exogenous vasopressin. When given in physiological dosing regimens, vasopressin appears to be a safe adjunct to other therapy. Definite recommendations regarding indications for use, recommended dose, and long-term outcome in patients with hemorrhagic shock await a much needed prospective, randomized, controlled trial.

The influence of vasovagal response on the coagulation system

BACKGROUND

Vasovagal response (VVR) is provoked by a reduced venous blood return to the heart as a reaction to orthostatic stress and to haemorrhage. Recently, two cases were reported showing elevated plasma concentration of von-Willebrand-factor (VWF) and factor VIII (FVIII) after VVR due to venapuncture. Although the effect of epinephrine as trigger for VWF liberation is known, a connection between VVR and activation of the coagulation system has not been studied systematically.

METHODS

We examined 21 subjects with lower body negative pressure. We measured the plasma concentration of von-Willebrand-factor-antigen (VWF:Ag), the activity of von-Willebrand-factor-Ristocetin-Cofactor (VWF:RiCo) and FVIII at several stress-levels and consecutively split up the different VWF-multimers.

RESULTS

In 16 of 21 subjects VVR could be induced. These subjects showed a significant increase of VWF:Ag concentration in plasma and an increase of FVIII and VWF:RiCo activity. The five individuals who experienced all stress-levels without VVR did not show any changes in their clotting factor levels.

CONCLUSION

VVR leads to measurable changes in the coagulation system. This might be a further diagnostic tool in treating patients with syncope.

Fluid management in traumatic shock: a practical approach for mountain rescue. Official recommendations of the International Commission for Mountain Emergency Medicine (ICAR MEDCOM)

Sumann, Günther, Peter Paal, Peter Mair, John Ellerton, Tore Dahlberg, Gregoire Zen-Ruffinen, Ken Zafren, and Hermann Brugger. Fluid management in traumatic shock: a practical approach for mountain rescue. High Alt. Med. Biol. 10:71-75, 2009.-The management of severe injuries leading to traumatic shock in mountains and remote areas is a great challenge for emergency physicians and rescuers. Traumatic brain injury may further aggravate outcome. A mountain rescue mission may face severe limitations from the terrain and required rescue technique. The mission may be characterized by a prolonged prehospital care time, where urban traumatic shock protocols may not apply. Yet optimal treatment is of utmost importance. The aim of this study is to establish scientifically supported recommendations for fluid management that are feasible for the physician or paramedic attending such an emergency. A nonsystematic literature search was performed; the results and recommendations were discussed among the authors and accepted by the International Commission for Mountain Emergency Medicine (ICAR MEDCOM). Diagnostic and therapeutic strategies are discussed, as well as limitations on therapy in mountain rescue. An algorithm for fluid resuscitation, derived from the recommendations, is presented in Fig. 1. Focused on the key criterion of traumatic brain injury, different levels of blood pressure are presented as a goal of therapy, and the practical means for achieving these are given.

Studies of the outcome of the treatment with beta-blockers in secondary prevention of the ischemic heart disease

Convincing evidence of the decline of mortality has been achieved with beta-blockers in patients with an acute myocardial infarction and in post-infarction follow-up. The beta-blockers are also the most efficient antianginal medications for the decrease of ischemia in outpatients. They are highly efficient as a monotherapy for angina and are also a medication of choice for angina after the coronary. The objective of this work was an estimate of the use of beta-blockers in secondary prevention of the ischemic heart disease and eliminating doubts concerning their prescription. The method of the analysis sums up the results of a twenty-five- year study on of the outcome of the treatment with beta-blockers in secondary prevention of the ischemic heart disease. The method of the work implies an examination of the professional literature and the data-bases, such as MEDLINE, PubMed and KOBSON. The first studies concerned non-selective beta-blockers, used orally. The following studies concerned cardioselective beta-blockers, metoprolol and atenolol. Several studies followed also the effect of beta-blockers and heparin, or beta-blockers and antagonists of calcium towards placebo, in patients with an unstable angina pectoris. Beta-blockers are an essential drug in secondary prevention of the myocardial infarction and in chronic heart failure. The necessary condition for the efficiency of beta-blockers is an early use. Beta-blockers should be given within 12 hours after the appearance of pain. The continuation of the therapy with beta-blockers after the acute phase is considered to be important in the decrease of the infarction zone expansion. Prophylactic use of beta-blockers after the coronary has an excellent effect, above all in patients with a minor, uncomplicated coronary. Though certain groups of beta-blockers have some special characteristics, when it comes to the treatment of angina pectoris, all beta-blockers are efficient. Generally, patients react well to them. Preference is given to cardioselective remedies, in patients with diabetes or lung disease. Exhaustive controlled clinical studies affirm beta-blockers as drugs that reduce mortality in secondary prevention of the ischemic heart disease.

Arginine vasopressin: a promising rescue drug in the treatment of uncontrolled haemorrhagic shock

Haemorrhagic shock is one of the most frequent types of shock. If haemorrhage cannot be controlled and fluid resuscitation as well as catecholamines are insufficient to stabilize cardiovascular function, uncontrolled haemorrhagic shock occurs. Several approaches have been suggested as promising alternatives to volume resuscitation. The rationale for the use of arginine vasopressin (AVP) is the pharmacologic amplification of the neuroendocrine stress response. AVP-mediated vasoconstriction is the first physiologic step to haemostasis and shifts blood away from the bleeding site towards the heart, lungs and brain. Particularly, when uncontrolled haemorrhage is accompanied by traumatic brain injury this may help to reduce secondary neurological damage. Since AVP can prevent acute death only transiently, it must comprehensively be combined with rapid hospital admission, immediate control of haemorrhage followed by aggressive fluid resuscitation and blood transfusion. This review article summarizes current experimental and clinical evidence on the use of AVP in uncontrolled haemorrhagic shock.

Developing alternative strategies for the treatment of traumatic haemorrhagic shock

PURPOSE OF REVIEW

The optimal strategy of stabilizing haemodynamic function in uncontrolled traumatic haemorrhagic shock states is unclear. Although fluid replacement is established in controlled haemorrhagic shock, its use in uncontrolled haemorrhagic shock is controversial, because it may worsen bleeding.

RECENT FINDINGS

In the refractory phase of severe haemorrhagic shock, arginine vasopressin has been shown to be beneficial in selected cases due to an increase in arterial blood pressure, shift of blood away from a subdiaphragmatic bleeding site towards the heart and brain, and decrease in fluid resuscitation requirements. Especially in patients with severe traumatic brain injury, rapid stabilization of cardiocirculatory function is essential to ensure adequate brain perfusion and thus to prevent neurological damage and to improve outcome. In addition, despite wide distribution of highly developed and professional emergency medical systems in western industrialized countries, survival chances of patients with uncontrolled traumatic haemorrhagic shock in the prehospital setting are still poor.

SUMMARY

A multicenter, randomized, controlled, international clinical trial is being initiated to assess the effects of arginine vasopressin (10 IU) vs. saline placebo in prehospital traumatic haemorrhagic shock patients, not responding to standard shock treatment, being managed by helicopter emergency medical services [vasopressin in traumatic haemorrhagic shock (VITRIS.at) study].

The origin of vasovagal syncope: to protect the heart or to escape predation?

Major lines of evidence suggest that classical (emotional and orthostatic) vasovagal syncope (VVS) is not a disease, but rather a manifestation of a non-pathological trait. It is, therefore, reasonable to investigate the possible factors that may explain its origin and evolution. We reviewed the data available in the literature on the vasovagal reaction in humans and animals in order to identify possible similarities that might provide insight into the evolution of VVS. We found two processes which appear relevant to the investigation of VVS evolution: fear and threat bradycardia in animals, and the vasovagal reflex during hemorrhagic shock in humans and animals. We suggest that VVS in humans involves physiological mechanisms similar to those found in other vertebrates, and that this may indicate a common evolutionary root. The available data seem to suggest that VVS evolved as an advantageous response to inescapable predators or to stressful and possibly dangerous heart conditions. The inhibition of the sympathetic system, together with activation of the vagal system, characterizes VVS. The consequent slowing of the heart rate induced by VVS may constitute a beneficial break of the cardiac pump, thereby reducing myocardial oxygen consumption. We suggest that classical VVS did not evolve recently in the modern human lineage; rather, it should be regarded as a selected response, which probably evolved in the ancient past as a "defense mechanism" of the organism within some ancestral group(s) of vertebrates.

Reperfusion injury after hemorrhage: a collective review

OBJECTIVE

To review current knowledge of hemorrhagic shock and reperfusion injury.

SUMMARY BACKGROUND DATA

Patients with hemorrhagic shock require optimal resuscitation and cessation of ongoing bleeding. Often our resuscitative measures, while necessary, cause a wide range of detrimental physiologic effects. Research continues to answer questions regarding measurable endpoints and optimal fluids used in resuscitation. Elucidation and understanding of the complex metabolic pathways involved in reperfusion injury are areas of intense current investigative effort.

METHODS

A literature review was performed using MEDLINE and key words related to experimental and clinical studies concerning shock and reperfusion.

RESULTS

Experimental studies have shown that resuscitation with colloid and crystalloid show no difference in outcomes in critically ill patients. Laboratory studies are showing promising results with immunomodulation of response to injury. However, no clinical trials have shown significance yet.

CONCLUSIONS

It is unlikely that a single treatment modality or "magic bullet" will be able to substantially block such a complex regulated process unless performed before feedback mechanisms known to be in place. Ongoing translational research will inevitably have a major impact on patient care.

The role of blood transfusion in the management of upper and lower intestinal tract bleeding

Patients with gastrointestinal (GI) haemorrhage use 13.8% of all red blood cell transfusions in England. This review addresses the evidence for red blood cell, fresh frozen plasma and platelet transfusions in acute and chronic blood loss, from both the upper and lower intestinal tract. It reviews the indications for transfusion in GI bleeding, the haematological consequences of massive blood loss and massive transfusion, and the importance of managing coagulopathy in bleeding patients. It also looks at the safety and risks of blood transfusion, and provides clinicians with evidence to reduce unnecessary transfusion. Large controlled clinical trials of blood transfusion specifically in GI bleeding are required, along with further research into the use of adjuvant therapies such as recombinant activated factor VIIa. Changing clinician behaviour to reduce inappropriate blood transfusion remains a key target for future transfusion research.

Vasopressin improves survival in a porcine model of abdominal vascular injury

Introduction

We sought to determine and compare the effects of vasopressin, fluid resuscitation and saline placebo on haemodynamic variables and short-term survival in an abdominal vascular injury model with uncontrolled haemorrhagic shock in pigs.

Methods

During general anaesthesia, a midline laparotomy was performed on 19 domestic pigs, followed by an incision (width about 5 cm and depth 0.5 cm) across the mesenterial shaft. When mean arterial blood pressure was below 20 mmHg, and heart rate had declined progressively, experimental therapy was initiated. At that point, animals were randomly assigned to receive vasopressin (0.4 U/kg; n = 7), fluid resuscitation (25 ml/kg lactated Ringer's and 25 ml/kg 3% gelatine solution; n = 7), or a single injection of saline placebo (n = 5). Vasopressin-treated animals were then given a continuous infusion of 0.08 U/kg per min vasopressin, whereas the remaining two groups received saline placebo at an equal rate of infusion. After 30 min of experimental therapy bleeding was controlled by surgical intervention, and further fluid resuscitation was performed. Thereafter, the animals were observed for an additional hour.

Results

After 68 ± 19 min (mean ± standard deviation) of uncontrolled bleeding, experimental therapy was initiated; at that time total blood loss and mean arterial blood pressure were similar between groups (not significant). Mean arterial blood pressure increased in both vasopressin-treated and fluid-resuscitated animals from about 15 mmHg to about 55 mmHg within 5 min, but afterward it decreased more rapidly in the fluid resuscitation group; mean arterial blood pressure in the placebo group never increased. Seven out of seven vasopressin-treated animals survived, whereas six out of seven fluid-resuscitated and five out of five placebo pigs died before surgical intervention was initiated (P < 0.0001).

Conclusion

Vasopressin, but not fluid resuscitation or saline placebo, ensured short-term survival in this vascular injury model with uncontrolled haemorrhagic shock in sedated pigs.

Liver response to hemorrhagic shock and subsequent resuscitation: MRI analysis

The liver is a target for injury in low flow states. Markers of liver injury are either invasive or not rapidly responding. Magnetic resonance imaging (MRI) may offer a noninvasive alternative to evaluate liver injury due to reduced perfusion. Recently, we reported an MRI method (functional MRI [fMRI]) that enables us to follow liver perfusion by changing the enrichment of inspired gas (air, air-5% carbon dioxide, 95% oxygen-5% carbon dioxide). Rats were subjected to hemorrhagic shock (HS) (bleeding to a MAP of 25 mmHg) and randomized to no resuscitation or resuscitation with Ringer lactate (RL) or adrenaline infusion targeted to a MAP of 50 mmHg or baseline. Significantly decreased fMRI responses to hyperoxia and hypercapnia were observed immediately after HS. Liver enzymes levels, liver histology, and apoptosis assessments were normal immediately after hemorrhage, however, showed significant changes after 6 h. Functional MRI revealed that adrenaline, but not RL infusion, significantly (P < 0.01) improved liver perfusion. Similarly, liver injury, as assessed by liver enzyme levels, liver histology, and apoptosis, was attenuated to a greater extent with adrenaline resuscitation. No significant differences in liver perfusion and injury were noted between resuscitation to low (50 mmHg) versus high (baseline) MAP. This study shows that fMRI enables early assessment of changes in liver perfusion, resulting in liver injury or recovery, and therefore, it may be considered as a noninvasive, rapidly responding tool for following liver outcome subsequent to hemorrhage and resuscitation. Using fMRI, we showed that adrenaline may be preferable to RL as an initial measure to attenuate liver injury after HS.