185 research outputs found
Use of Ducted Head Baffles to Reduce Rear-row Cylinder Temperatures of an Air-cooled Aircraft Engine
Influence of TRPM4 rs8104571 Genotype on Intracranial Pressure and Outcomes in African Americans With Traumatic Brain Injury
The TRPM4 gene codes for a membrane ion channel subunit related to inflammation in the central nervous system. Recent investigation has identified an association between TRPM4 single nucleotide polymorphisms (SNPs) rs8104571 and rs150391806 and increased intracranial (ICP) pressure following traumatic brain injury (TBI). We assessed the influence of these genotypes on clinical outcomes and ICP in TBI patients. We included 292 trauma patients with TBI. DNA extraction and real-time PCR were used for TRPM4 rs8104571 and rs150391806 allele discrimination. Five participants were determined to have the rs8104571 homozygous variant genotype, and 20 participants were identified as heterozygotes; 24 of these 25 participants were African American. No participants had rs150391806 variant alleles, preventing further analysis of this SNP. Genotypes containing the rs8104571 variant allele were associated with decreased Glasgow outcome scale-extended (GOSE) score (P = 0.0231), which was also consistent within our African-American subpopulation (P = 0.0324). Regression analysis identified an association between rs8104571 variant homozygotes and mortality within our overall population (P = 0.0230) and among African Americans (P = 0.0244). Participants with rs8104571 variant genotypes exhibited an overall increase in ICP (P = 0.0077), although a greater frequency of ICP measurements \u3e 25 mmHg was observed in wild-type participants (P = \u3c 0.0001). We report an association between the TRPM4 rs8104571 variant allele and poor outcomes following TBI. These findings can potentially be translated into a precision medicine approach for African Americans following TBI utilizing TRPM4-specific pharmaceutical interventions. Validation through larger cohorts is warranted
Impact of Transfused Citrate on Pathophysiology in Massive Transfusion
UNLABELLED: This narrative review article seeks to highlight the effects of citrate on physiology during massive transfusion of the bleeding patient.
DATA SOURCES: A limited library of curated articles was created using search terms including citrate intoxication, citrate massive transfusion, citrate pharmacokinetics, hypocalcemia of trauma, citrate phosphate dextrose, and hypocalcemia in massive transfusion. Review articles, as well as prospective and retrospective studies were selected based on their relevance for inclusion in this review.
STUDY SELECTION: Given the limited number of relevant studies, studies were reviewed and included if they were written in English. This is not a systematic review nor a meta-analysis.
DATA EXTRACTION AND SYNTHESIS: As this is not a meta-analysis, new statistical analyses were not performed. Relevant data were summarized in the body of the text.
CONCLUSIONS: The physiologic effects of citrate independent of hypocalcemia are poorly understood. While a healthy individual can rapidly clear the citrate in a unit of blood (either through the citric acid cycle or direct excretion in urine), the physiology of hemorrhagic shock can lead to decreased clearance and prolonged circulation of citrate. The so-called Diamond of Death of bleeding-coagulopathy, acidemia, hypothermia, and hypocalcemia-has a dynamic interaction with citrate that can lead to a death spiral. Hypothermia and acidemia both decrease citrate clearance while circulating citrate decreases thrombin generation and platelet function, leading to ionized hypocalcemia, coagulopathy, and need for further transfusion resulting in a new citrate load. Whole blood transfusion typically requires lower volumes of transfused product than component therapy alone, resulting in a lower citrate burden. Efforts should be made to limit the amount of citrate infused into a patient in hemorrhagic shock while simultaneously addressing the induced hypocalcemia
Does an Early, Balanced Resuscitation Strategy Reduce the Incidence of Hypofibrinogenemia in Hemorrhagic Shock?
OBJECTIVES: Some centers have recommended including concentrated fibrinogen replacement in massive transfusion protocols (MTPs). Given our center\u27s policy of aggressive early balanced resuscitation (1:1:1), beginning prehospital, we hypothesized that our rates of hypofibrinogenemia may be lower than those previously reported.
METHODS: In this retrospective cohort study, patients presenting to our trauma center November 2017 to April 2021 were reviewed. Patients were defined as hypofibrinogenemic (HYPOFIB) if admission fibrinogen
RESULTS: Of 29 782 patients, 6618 level 1 activations, and 1948 patients receiving emergency release blood,
CONCLUSIONS: Low rates of hypofibrinogenemia were found in our center which treats hemorrhage with early, balanced resuscitation. Previously reported higher rates may be partially due to unbalanced resuscitation and/or delay in resuscitation initiation. Routine empiric inclusion of concentrated fibrinogen replacement in MTPs is not supported by the currently available data.
LEVEL OF EVIDENCE: Level III
Does an Early, Balanced Resuscitation Strategy Reduce the Incidence of Hypofibrinogenemia in Hemorrhagic Shock?
OBJECTIVES: Some centers have recommended including concentrated fibrinogen replacement in massive transfusion protocols (MTPs). Given our center\u27s policy of aggressive early balanced resuscitation (1:1:1), beginning prehospital, we hypothesized that our rates of hypofibrinogenemia may be lower than those previously reported.
METHODS: In this retrospective cohort study, patients presenting to our trauma center November 2017 to April 2021 were reviewed. Patients were defined as hypofibrinogenemic (HYPOFIB) if admission fibrinogen
RESULTS: Of 29 782 patients, 6618 level 1 activations, and 1948 patients receiving emergency release blood,
CONCLUSIONS: Low rates of hypofibrinogenemia were found in our center which treats hemorrhage with early, balanced resuscitation. Previously reported higher rates may be partially due to unbalanced resuscitation and/or delay in resuscitation initiation. Routine empiric inclusion of concentrated fibrinogen replacement in MTPs is not supported by the currently available data.
LEVEL OF EVIDENCE: Level III
Pre-hospital transfusion of plasma in hemorrhaging trauma patients independently improves hemostatic competence and acidosis
BACKGROUND: The early use of blood products has been associated with improved patient outcomes following severe hemorrhage or traumatic injury. We aimed to investigate the influence of pre-hospital blood products (i.e. plasma and/or RBCs) on admission hemostatic properties and patient outcomes. We hypothesized that pre-hospital plasma would improve hemostatic function as evaluated by rapid thrombelastography (rTEG). METHODS: We conducted a prospective observational study recruiting 257 trauma patients admitted to a Level I trauma center having received either blood products pre-hospital or in-hospital within 6 hours of admission. Clinical data on patient demographics, blood biochemistry, injury severity score and mortality were collected. Admission rTEG was conducted to characterize the coagulation profile and hemostatic function. RESULTS: 75 patients received pre-hospital plasma and/or RBCs (PH group; nearly half received both RBCs and plasma) whereas 182 patients only received in-hospital blood products (RBCs, Plasma and Platelets) within 6 hours of admission (IH group). PH patients had lower Glasgow coma scale (GCS) scores, more penetrating injuries, lower systolic blood pressures, lower hemoglobin levels, lower platelet counts and greater acidosis upon ED admission than the IH group (all p < 0.05). Despite differences in type of injury and admission vitals indicating that the PH group had more signs of bleeding than the IH group, there were no significant differences in in-hospital mortality (PH 26.7% vs. IH 20.9% p = 0.31). When comparing rTEG variables between PH patients transfused with 0, 1 or 2 units of plasma, more pre-hospital plasma transfusion was tendency towards improved rTEG variables. When adjusting for pre-hospital RBC, pre-hospital plasma was associated with significantly higher rTEG MA (p = 0.012) at hospital admission. DISCUSSION: After adjusting for pre-hospital RBCs, pre-hospital plasma transfusion was independently associated with increased rTEG MA, as well as arrival indices of shock and hemodynamic instability. Besides more severe injury and worse clinical presentation, the group that received pre-hospital transfusion had early and late mortality similar to patients not transfused pre-hospital. CONCLUSIONS: These data suggest that early administration of plasma can provide significant hemostatic and potential survival benefit to severely hemorrhaging trauma patients
Traumatic Endotheliopathy:A Prospective Observational Study of 424 Severely Injured Patients
OBJECTIVE: Investigate and confirm the association between sympathoadrenal activation, endotheliopathy and poor outcome in trauma patients. BACKGROUND: The association between sympathoadrenal activation, endotheliopathy, and poor outcome in trauma has only been demonstrated in smaller patient cohorts and animal models but needs confirmation in a large independent patient cohort. METHODS: Prospective observational study of 424 trauma patients admitted to a level 1 Trauma Center. Admission plasma levels of catecholamines (adrenaline, noradrenaline) and biomarkers reflecting endothelial damage (syndecan-1, thrombomodulin, and sE-selectin) were measured and demography, injury type and severity, physiology, treatment, and mortality up till 28 days were recorded. RESULTS: Patients had a median ISS of 17 with 72% suffering from blunt injury. Adrenaline and noradrenaline correlated with syndecan-1 (r = 0.38, P < 0.001 and r = 0.23, P < 0.001, respectively) but adrenaline was the only independent predictor of syndecan-1 by multiple linear regression adjusted for age, injury severity score, Glascow Coma Scale, systolic blood pressure, base excess, platelet count, hemoglobin, prehospital plasma, and prehospital fluids (100 pg/mL higher adrenaline predicted 2.75 ng/mL higher syndecan-1, P < 0.001). By Cox analyses adjusted for age, sex, injury severity score, Glascow Coma Scale, base excess, platelet count and hemoglobin, adrenaline, and syndecan-1 were the only independent predictors of both <24-hours, 7-day and 28-day mortality (all P < 0.05). Furthermore, noradrenaline was an independent predictor of <24-hours mortality and thrombomodulin was an independent predictor of 7-day and 28-day mortality (all P < 0.05). CONCLUSIONS: We confirmed that sympathoadrenal activation was strongly and independently associated with endothelial glycocalyx and cell damage (ie, endotheliopathy) and furthermore that sympathoadrenal activation and endotheliopathy were independent predictors of mortality in trauma patients
Bacteraemia in patients admitted to an urban hospital in West Africa
BACKGROUND: Few studies on bacteraemia in Africa have been published. We aimed to prospectively identify the causative organisms of bacteraemia in The Gambia and their relation to clinical diagnoses, outcome and antimicrobial susceptibility. METHODS: Between November 2003 and February 2005 we studied those admitted to the Medical Research Council hospital who were suspected of having bacteraemia. We documented clinical features, outcome, pathogens identified and their susceptibility patterns, and searched for factors associated with bacteraemia. RESULTS: 871 patients were admitted and had a blood culture taken. The median age was 2 years (range 2 months to 80 years) and 36 of 119 tested were HIV positive; 54.5% were male. 297 (34%) had a positive result and 93 (10.7% overall) were considered a genuine pathogen. Those with bacteraemia were more likely to die in hospital (OR 2.79; 1.17–6.65, p = 0.017) and to have a high white cell count (WCC; OR 1.81;95% CI 1.09–3.02; p = 0.022). Three organisms accounted for 73% of bacteraemias: Streptococcus pneumoniae (45.2%), Staphylococcus aureus (18.3%) and Escherichia coli (9.7%) while non-typhoidal salmonellae (NTS) accounted for 8.6%. Antimicrobial susceptibility of S. pneumoniae was very high to penicillin (97.5%); high resistance was found to co-trimoxazole. S. aureus was generally highly susceptible to cloxacillin, gentamicin and chloramphenicol. E. coli and NTS were all susceptible to ciprofloxacin and mostly susceptible to gentamicin. Thirteen (33%) S. pneumoniae isolates were of serotypes contained in a 7-valent pneumococcal conjugate vaccine and 20 (51.3%) were of the same serogroup. CONCLUSION: In The Gambia, those with bacteraemia are more likely than those without to die in hospital and to have a raised peripheral blood WCC. S. pneumoniae is the most common organism isolated. Introduction of a pneumococcal conjugate vaccine can be expected to lead to a reduction in disease incidence
Robust physical methods that enrich genomic regions identical by descent for linkage studies: confirmation of a locus for osteogenesis imperfecta
<p>Abstract</p> <p>Background</p> <p>The monogenic disease osteogenesis imperfecta (OI) is due to single mutations in either of the collagen genes ColA1 or ColA2, but within the same family a given mutation is accompanied by a wide range of disease severity. Although this phenotypic variability implies the existence of modifier gene variants, genome wide scanning of DNA from OI patients has not been reported. Promising genome wide marker-independent physical methods for identifying disease-related loci have lacked robustness for widespread applicability. Therefore we sought to improve these methods and demonstrate their performance to identify known and novel loci relevant to OI.</p> <p>Results</p> <p>We have improved methods for enriching regions of identity-by-descent (IBD) shared between related, afflicted individuals. The extent of enrichment exceeds 10- to 50-fold for some loci. The efficiency of the new process is shown by confirmation of the identification of the Col1A2 locus in osteogenesis imperfecta patients from Amish families. Moreover the analysis revealed additional candidate linkage loci that may harbour modifier genes for OI; a locus on chromosome 1q includes COX-2, a gene implicated in osteogenesis.</p> <p>Conclusion</p> <p>Technology for physical enrichment of IBD loci is now robust and applicable for finding genes for monogenic diseases and genes for complex diseases. The data support the further investigation of genetic loci other than collagen gene loci to identify genes affecting the clinical expression of osteogenesis imperfecta. The discrimination of IBD mapping will be enhanced when the IBD enrichment procedure is coupled with deep resequencing.</p
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