Michael T. Ganter

Bio: Michael T. Ganter is an academic researcher from Winterthur Museum, Garden and Library. The author has contributed to research in topics: Lung injury & Coagulopathy. The author has an hindex of 26, co-authored 81 publications receiving 4328 citations. Previous affiliations of Michael T. Ganter include University of Zurich & University of California.

Acute traumatic coagulopathy: initiated by hypoperfusion: modulated through the protein C pathway?

Abstract: Objectives: Coagulopathy following major trauma is conventionally attributed to activation and consumption of coagulation factors. Recent studies have identified an acute coagulopathy present on admission that is independent of injury severity. We hypothesized that early coagulopathy is due to tissue hypoperfusion, and investigated derangements in coagulation associated with this. Methods: This was a prospective cohort study of major trauma patients admitted to a single trauma center. Blood was drawn within 10 minutes of arrival for analysis of partial thromboplastin and prothrombin times, prothrombin fragments 12, fibrinogen, thrombomodulin, protein C, plasminogen activator inhibitor-1, and D-dimers. Base deficit (BD) was used as a measure of tissue hypoperfusion. Results: A total of 208 patients were enrolled. Patients without tissue hypoperfusion were not coagulopathic, irrespective of the amount of thrombin generated. Prolongation of the partial thromboplastin and prothrombin times was only observed with an increased BD. An increasing BD was associated with high soluble thrombomodulin and low protein C levels. Low protein C levels were associated with prolongation of the partial thromboplastin and prothrombin times and hyperfibrinolysis with low levels of plasminogen activator inhibitor-1 and high D-dimer levels. High thrombomodulin and low protein C levels were significantly associated with increased mortality, blood transfusion requirements, acute renal injury, and reduced ventilator-free days. Conclusions: Early traumatic coagulopathy occurs only in the presence of tissue hypoperfusion and appears to occur without significant consumption of coagulation factors. Alterations in the thrombomodulin-protein C pathway are consistent with activated protein C activation and systemic anticoagulation. Admission plasma thrombomodulin and protein C levels are predictive of clinical outcomes following major trauma.

Acute Coagulopathy of Trauma: Hypoperfusion Induces Systemic Anticoagulation and Hyperfibrinolysis

Abstract: BACKGROUND: Coagulopathy is present at admission in 25% of trauma patients, is associated with shock and a 5-fold increase in mortality. The coagulopathy has recently been associated with systemic activation of the protein C pathway. This study was designed to characterize the thrombotic, coagulant and fibrinolytic derangements of trauma-induced shock. METHODS: This was a prospective cohort study of major trauma patients admitted to a single trauma center. Blood was drawn within 10 minutes of arrival for analysis of partial thromboplastin and prothrombin times, prothrombin fragments 1 + 2 (PF1 + 2), fibrinogen, factor VII, thrombomodulin, protein C, plasminogen activator inhibitor-1 (PAI-1), thrombin activatable fibrinolysis inhibitor (TAFI), tissue plasminogen activator (tPA), and D-dimers. Base deficit was used as a measure of tissue hypoperfusion. RESULTS: Two hundred eight patients were studied. Systemic hypoperfusion was associated with anticoagulation and hyperfibrinolysis. Coagulation was activated and thrombin generation was related to injury severity, but acidosis did not affect Factor VII or PF1 + 2 levels. Hypoperfusion-induced increase in soluble thrombomodulin levels was associated with reduced fibrinogen utilization, reduction in protein C and an increase in TAFI. Hypoperfusion also resulted in hyperfibrinolysis, with raised tPA and D-Dimers, associated with the observed reduction in PAI-1 and not alterations in TAFI. CONCLUSIONS: Acute coagulopathy of trauma is associated with systemic hypoperfusion and is characterized by anticoagulation and hyperfibrinolysis. There was no evidence of coagulation factor loss or dysfunction at this time point. Soluble thrombomodulin levels correlate with thrombomodulin activity. Thrombin binding to thrombomodulin contributes to hyperfibrinolysis via activated protein C consumption of PAI-1.

Coagulation monitoring: current techniques and clinical use of viscoelastic point-of-care coagulation devices

Abstract: Perioperative monitoring of blood coagulation is critical to better understand causes of hemorrhage, to guide hemostatic therapies, and to predict the risk of bleeding during the consecutive anesthetic or surgical procedures. Point-of-care (POC) coagulation monitoring devices assessing the viscoelastic properties of whole blood, i.e., thrombelastography, rotation thrombelastometry, and Sonoclot analysis, may overcome several limitations of routine coagulation tests in the perioperative setting. The advantage of these techniques is that they have the potential to measure the clotting process, starting with fibrin formation and continue through to clot retraction and fibrinolysis at the bedside, with minimal delays. Furthermore, the coagulation status of patients is assessed in whole blood, allowing the plasmatic coagulation system to interact with platelets and red cells, and thereby providing useful additional information on platelet function. Viscoelastic POC coagulation devices are increasingly being used in clinical practice, especially in the management of patients undergoing cardiac and liver surgery. Furthermore, they provide useful information in a large variety of clinical scenarios, e.g., massive hemorrhage, assessment of hypo- and hypercoagulable states, guiding pro- and anticoagulant therapies, and in diagnosing of a surgical bleeding. A surgical etiology of bleeding has to be considered when viscoelastic test results are normal. In summary, viscoelastic POC coagulation devices may help identify the cause of bleeding and guide pro- and anticoagulant therapies. To ensure optimal accuracy and performance, standardized procedures for blood sampling and handling, strict quality controls and trained personnel are required.

Global patient outcomes after elective surgery: Prospective cohort study in 27 low-, middle- and high-income countries

Abstract: Background As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. Methods We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. Results A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2–7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. Conclusions Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care.

Interleukin-1β Causes Acute Lung Injury via αvβ5 and αvβ6 Integrin–Dependent Mechanisms

Abstract: Interleukin (IL)-1beta has previously been shown to be among the most biologically active cytokines in the lungs of patients with acute lung injury (ALI). Furthermore, there is experimental evidence that lung vascular permeability increases after short-term exposure to IL-1 protein, although the exact mechanism is unknown. Therefore, the objective of this study was to determine the mechanisms of IL-1beta-mediated increase in lung vascular permeability and pulmonary edema following transient overexpression of this cytokine in the lungs by adenoviral gene transfer. Lung vascular permeability increased with intrapulmonary IL-1beta production with a maximal effect 7 days after instillation of the adenovirus. Furthermore, inhibition of the alphavbeta6 integrin and/or transforming growth factor-beta attenuated the IL-1beta-induced ALI. The results of in vitro studies indicated that IL-1beta caused the activation of transforming growth factor-beta via RhoA/alphavbeta6 integrin-dependent mechanisms and the inhibition of the alphavbeta6 integrin and/or transforming growth factor-beta signaling completely blocked the IL-1beta-mediated protein permeability across alveolar epithelial cell monolayers. In addition, IL-1beta increased protein permeability across lung endothelial cell monolayers via RhoA- and alphavbeta5 integrin-dependent mechanisms. The final series of in vivo experiments demonstrated that pretreatment with blocking antibodies to both the alphavbeta5 and alphavbeta6 integrins had an additive protective effect against IL-1beta-induced ALI. In summary, these results demonstrate a critical role for the alphavbeta5/beta6 integrins in mediating the IL-1beta-induced ALI and indicate that these integrins could be a potentially attractive therapeutic target in ALI.

Part 9: Post-Cardiac Arrest Care: 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Abstract: There is increasing recognition that systematic post–cardiac arrest care after return of spontaneous circulation (ROSC) can improve the likelihood of patient survival with good quality of life. This is based in part on the publication of results of randomized controlled clinical trials as well as a description of the post–cardiac arrest syndrome. 1–3 Post–cardiac arrest care has significant potential to reduce early mortality caused by hemodynamic instability and later morbidity and mortality from multiorgan failure and brain injury. 3,4 This section summarizes our evolving understanding of the hemodynamic, neurological, and metabolic abnormalities encountered in patients who are initially resuscitated from cardiac arrest. The initial objectives of post–cardiac arrest care are to ● Optimize cardiopulmonary function and vital organ perfusion. ● After out-of-hospital cardiac arrest, transport patient to an appropriate hospital with a comprehensive post–cardiac arrest treatment system of care that includes acute coronary interventions, neurological care, goal-directed critical care, and hypothermia. ● Transport the in-hospital post–cardiac arrest patient to an appropriate critical-care unit capable of providing comprehensive post–cardiac arrest care. ● Try to identify and treat the precipitating causes of the arrest and prevent recurrent arrest.

Part 14: Pediatric Advanced Life Support 2010 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care

Abstract: In contrast to adults, cardiac arrest in infants and children does not usually result from a primary cardiac cause. More often it is the terminal result of progressive respiratory failure or shock, also called an asphyxial arrest. Asphyxia begins with a variable period of systemic hypoxemia, hypercapnea, and acidosis, progresses to bradycardia and hypotension, and culminates with cardiac arrest.1 Another mechanism of cardiac arrest, ventricular fibrillation (VF) or pulseless ventricular tachycardia (VT), is the initial cardiac rhythm in approximately 5% to 15% of pediatric in-hospital and out-of-hospital cardiac arrests;2,–,9 it is reported in up to 27% of pediatric in-hospital arrests at some point during the resuscitation.6 The incidence of VF/pulseless VT cardiac arrest rises with age.2,4 Increasing evidence suggests that sudden unexpected death in young people can be associated with genetic abnormalities in myocyte ion channels resulting in abnormalities in ion flow (see “Sudden Unexplained Deaths,” below). Since 2010 marks the 50th anniversary of the introduction of cardiopulmonary resuscitation (CPR),10 it seems appropriate to review the progressive improvement in outcome of pediatric resuscitation from cardiac arrest. Survival from in-hospital cardiac arrest in infants and children in the 1980s was around 9%.11,12 Approximately 20 years later, that figure had increased to 17%,13,14 and by 2006, to 27%.15,–,17 In contrast to those favorable results from in-hospital cardiac arrest, overall survival to discharge from out-of-hospital cardiac arrest in infants and children has not changed substantially in 20 years and remains at about 6% (3% for infants and 9% for children and adolescents).7,9 It is unclear why the improvement in outcome from in-hospital cardiac arrest has occurred, although earlier recognition and management of at-risk patients on general inpatient units …

The Ratio of Blood Products Transfused Affects Mortality in Patients Receiving Massive Transfusions at a Combat Support Hospital

Abstract: Background Patients with severe traumatic injuries often present with coagulopathy and require massive transfusion. The risk of death from hemorrhagic shock increases in this population. To treat the coagulopathy of trauma, some have suggested early, aggressive correction using a 1:1 ratio of plasma to red blood cell (RBC) units. Methods We performed a retrospective chart review of 246 patients at a US Army combat support hospital, each of who received a massive transfusion (>/=10 units of RBCs in 24 hours). Three groups of patients were constructed according to the plasma to RBC ratio transfused during massive transfusion. Mortality rates and the cause of death were compared among groups. Results For the low ratio group the plasma to RBC median ratio was 1:8 (interquartile range, 0:12-1:5), for the medium ratio group, 1:2.5 (interquartile range, 1:3.0-1:2.3), and for the high ratio group, 1:1.4 (interquartile range, 1:1.7-1:1.2) (p Conclusions In patients with combat-related trauma requiring massive transfusion, a high 1:1.4 plasma to RBC ratio is independently associated with improved survival to hospital discharge, primarily by decreasing death from hemorrhage. For practical purposes, massive transfusion protocols should utilize a 1:1 ratio of plasma to RBCs for all patients who are hypocoagulable with traumatic injuries.