Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “HEMOSTASIS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources
PubMed2001

Vascular complications after percutaneous coronary interventions following hemostasis with manual compression versus arteriotomy closure devices.

OBJECTIVES: We evaluated the vascular complications after hemostasis with arteriotomy closure devices (ACD) versus manual compression after percutaneous coronary interventions (PCI). BACKGROUND: Previous clinical studies have indicated that ACD can be used for achievement of hemostasis and early ambulation after PCI. This study investigated the safety of ACD in achieving hemostasis after PCI compared with manual compression in a large cohort of consecutive patients. METHODS: A total of 5,093 patients were followed after PCI was performed with the transfemoral approach. Univariate and multivariate analysis were used to identify the predictors of vascular complications with ACD (n = 516) or with manual compression (n = 5,892) as a hemostasis option after sheath removal. RESULTS: The use of ACD was associated with a more frequent occurrence of hematoma compared with manual compression (9.3 vs. 5.1%, p < 0.001). There was also a higher rate of significant hematocrit drop (>15%) with ACD versus manual compression (5.2% vs. 2.5%, p < 0.001). Similar rates of pseudoaneurysm and arteriovenous fistulae were noted with either hemostasis technique. Vascular surgical repair at the access site was required more often with ACD versus manual compression (2.5 vs. 1.5%, p = 0.03). CONCLUSIONS: In this early experience with ACD after PCI, their use was associated with higher vascular complication rates than hemostasis with manual compression.

Aged↗
PubMed2001

High intensity focused ultrasound: a method of hemostasis.

Acoustic hemostasis is a new field of ultrasound research in which high intensity focused ultrasound (HIFU) is used to induce hemostasis in actively bleeding, injured solid organs and blood vessels. In animal studies, moderate to profuse bleeding from parenchymal and vascular injuries has been arrested within approximately 1 minute of HIFU application, even when a large dose of heparin was administered. Moreover, acoustic hemostasis has shown promise in cauterizing large regions of liver, providing a method for bloodless resectioning of abnormal tissue. Two distinct physical mechanisms of HIFU appear to contribute to hemostasis: (1) a thermal mechanism in which absorption of sound leads to temperature elevations, and (2) mechanical mechanisms (acoustic cavitation) in which gas and vapor-filled voids oscillate with large displacement amplitudes. While the thermal mechanism results in a temperature increase in excess of 70 degrees C in about 1 second, the mechanical mechanism appears to result in structural disruption of tissue and possible release of coagulation-inducing tissue factors. Of utmost importance in further development of HIFU as a clinical tool is targeting and monitoring of the HIFU treatment. We have obtained initial success in integrating HIFU with ultrasound imaging so as to develop an image-guided therapy system. Image-guided acoustic hemostasis may provide a valuable method of hemostasis in surgical and prehospital settings with applications in trauma and elective surgery.

Animals↗
PubMed1986

Hemostasis--therapeutic alternatives to the laser.

In clinical practice, there are a number of other endoscopic procedures for attaining hemostasis available as alternatives to laser hemostasis. Of these the following may be emphasized: Modified electrocoagulation procedures such as EHT coagulation, bipolar or multipolar coagulation, and sclerotherapy. The efficacy of these "laser-alternative" methods of hemostasis has already been demonstrated in clinical studies, and is unquestioned. Large comparative investigations that would provide definitive information on the relative effectiveness of the various techniques, have yet to be carried out. If, however, we consider such aspects as practicability and economy, the laser would appear to be a "dinosaur" among the endoscopic procedures presently available for hemostasis. The oldest recognized fiber-endoscopic instrument for hemostasis, it is anything but highly mobile, and is bound to a fixed location. In addition, it is as expensive as a museum exhibit. If the only indication for its use were hemostasis, it would probably have vanished from the scene.

Electrocoagulation↗
PubMed1998

[Critical analysis of hemostasis disorders in the course of eclampsia. Report of 106 cases].

OBJECTIVE: Study of hemostatic disorders during eclampsia, their risk factors, maternal complications and associated mortality. METHODS: Retrospective study concerning 106 cases of severe eclampsia treated in intensive care between September 1992 and December 96. Patients with or without hemostatic disorders were compared for laboratory findings, maternal complications and mortality. RESULTS: Forty patients had hemostasis disorders as follows: isolated thrombopenia in 19 cases, disseminated intravascular coagulation (DIC) in 5 cases, Hellp syndrome associated to DIC in 7 cases and Hellp syndrome in 9 cases. Hemostasis disorders were associated to maternal advanced age, but not with gestational age or blood pressure in admission or time of convulsions. Complications and mortality associated with hemostasis disorders were more frequent compared to patients without hemostasis disorders. Among the 17 deaths of our series, 10 had hemostasis disorders. CONCLUSION: Hemostasis disorders were prognosis factors in eclampsia requiring systematic laboratory tests at admission and immediate delivery.

Adult↗
PubMed2000

Efficacy of a novel hemostatic agent in animal models of impaired hemostasis.

This study evaluated the efficacy of a novel sprayable hemostat under both normal conditions and those of compromised coagulation. CoStasistrade mark Surgical Hemostat ("CoStasis"), containing collagen, thrombin, and autologous plasma, was compared to Instattrade mark collagen sponge, an investigational fibrin sealant, and a no treatment control, for the ability to control bleeding in a rabbit kidney model. Hemostatic performance was determined by time to hemostasis and blood loss in a nonsurvival, randomized, in vivo bleeding rabbit kidney model. Under conditions of normal coagulation, as well as aspirin and heparin treatment, hemostasis was achieved faster with CoStasistrade mark than with Instattrade mark and fibrin sealant. With the exception of the time to hemostasis using Instattrade mark sponge in heparinized rabbits, all differences were statistically significant (p < 0.03, Wilcoxon). Blood loss, where measured, was lower with CoStasistrade mark than with the other hemostats under the three coagulation conditions. Statistical significance, (p < 0.03, Wilcoxon), was achieved with all comparisons except with fibrin sealant in aspirin treated animals. The combination of collagen, thrombin, and autologous plasma used in CoStasis, can achieve significantly faster hemostasis than the conventional atraumatic hemostats, collagen sponge, and fibrin sealant under normal conditions and conditions of impaired hemostasis.

Animals↗
PubMed1998

The use of bipolar cautery, laparosonic coagulating shears, and vascular clips for hemostasis of small and medium-sized vessels.

Advanced laparoscopic surgery requires a reliable method of hemostasis. In order to determine the efficacy of common hemostatic devices, we tested bipolar electrosurgery (BPES), laparosonic coagulating shears (LCS), and vascular clips (VC) on arteries of various sizes to compare the strength of hemostasis against elevated intraarterial pressure. The procedures were performed on a porcine model through a laparotomy. Segments of visceral arteries were isolated and cannulated with an angiocatheter that was linked to a pressure monitor. After hemostasis with the tested instrument and division of the vessel, the intraarterial pressure was elevated by infusion of saline solution through the angiocatheter. The pressure was recorded when bleeding occurred through the cut end of the vessel or when the pressure reached 300 mm Hg. All three devices were effective in maintaining hemostasis on small (diameter, 0.25-0.5 mm) and medium-sized arteries (diameter, 2-3.5 mm) with a success rate ranging between 75% and 100% (p = n.s.). Practice and technical finesse were required with the use of the LCS and BPES before excellent results could be obtained. The LCS has an advantage over BPES because it allows the surgeon to perform hemostasis and division simultaneously, thus keeping the operating field clean and avoiding instrument adhesion to the tissue.

Animals↗
PubMed2006

How does spontaneous hemostasis occur in ruptured cerebral aneurysms? Preliminary investigation on 247 clipping surgeries.

BACKGROUND: Rupture of cerebral aneurysms results in subarachnoid hemorrhage. In many cases, bleeding from aneurysms spontaneously arrests. Although bleeding from cerebral aneurysms has been reported to arrest from outside, bleeding from some aneurysms can arrest in different ways. METHODS: Between April 2002 and March 2004, we prospectively investigated mechanisms of spontaneous hemostasis in ruptured aneurysms by macroscopic examination when performing craniotomy and clipping surgeries. RESULTS: Hemostatic mechanisms were investigated in 247 patients with ruptured aneurysm (77 men, 170 women; age range, 25-95 years). Hemostatic mechanisms were divided into 3 different patterns. In the most common pattern (79.4%), the surface of the aneurysm rupture point was sealed from the outside by a platelet plug or fibrin net (outside-arrest pattern). In some aneurysms (10.1%), a thrombus or platelet plug was attached to the rupture point from inside the aneurysm (inside-arrest pattern). In a very small number of aneurysms (1.6%), a naked thrombus covered the hole made on the arterial wall or small remnant of the aneurysmal dome (bursting pattern) The mechanism remained unclear in the remaining 8.9% of aneurysms. Multivariate analysis revealed that alert consciousness on admission (WFNS grade I) significantly associated with usual hemostasis (outside arrest pattern: OR, 3.8; 95% CI, 1.4-10.0; P = .008). Borderline association with usual hemostasis was found in aneurysms with a size of 5 or smaller than 5 mm (OR, 2.6; 95% CI, 0.99-7.1; P = .052). CONCLUSIONS: The present preliminary study revealed that arrest of bleeding from a ruptured cerebral aneurysm does not always occur from outside the aneurysm. Unusual mechanisms of hemostasis are seen in approximately 12% of ruptured aneurysm. The outside-arrest-pattern aneurysm was more common for smaller aneurysms, and these patients tended to be of better grade. Further studies are necessary to explore the mechanism of hemostasis for ruptured cerebral aneurysms.

Adult↗
PubMed2002

Argon ion beam hemostasis with albumin after liver resection.

BACKGROUND: Bleeding is common after liver resection and establishing hemostasis with sutures or argon beam coagulation can be difficult. In our laboratory, concentrated albumin applied to the liver surface before argon beam coagulation improves sealing of the resected surface of the liver, including closure of blood vessels and ducts not generally seen with standard argon beam coagulation. METHODS: Domestic swine underwent heparinization, then laparotomy and wedge resection of the left medial segment of the liver, using finger fracture technique. Blood vessels and ducts 5 mm or greater were ligated. For achieving hemostasis, the animals were randomized to either a control group using argon beam coagulation alone (n = 15) or an albumin group using argon beam coagulation with concentrated 38% albumin (n = 13). After initial hemostasis, the resected liver surfaces were packed for 3 minutes. Repeated applications of argon beam coagulation with or without albumin were performed as needed, followed by 3 minutes of repacking, until complete hemostasis was achieved. Liver functions and blood counts were examined 4 days postoperatively. RESULTS: The albumin group was less likely to require repeat applications of argon beam coagulation than control animals (mean 0.5 versus 1.5 times, P = 0.006). The total time of argon beam coagulation was significantly shorter in the albumin group (mean 90 versus 154 seconds, P = 0.001). CONCLUSIONS: Adding albumin to the liver surface substantially increases the durability of the repaired surface and reduces the time needed to achieve stable hemostasis when compared with standard argon beam coagulation. Further investigations using this technique are warranted.

Albumins↗
PubMed2004

A prospective, randomized trial comparing mechanical methods of hemostasis plus epinephrine injection to epinephrine injection alone for bleeding peptic ulcer.

BACKGROUND: The hemostatic efficacy of mechanical methods of hemostasis, together with epinephrine injection, was compared with that of epinephrine injection alone in bleeding peptic ulcer. METHODS: Ninety patients with a peptic ulcer with active bleeding or a non-bleeding visible vessel were randomly assigned to undergo a mechanical method of hemostasis (23 hemoclip application, 22 band ligation) plus epinephrine injection, or epinephrine injection alone. RESULTS: The two groups were similar with respect to all background variables. Initial hemostasis was achieved in 44/45 (97.8%) patients in both groups. The mean number of hemoclips and elastic bands applied were 2.8: 95% CI[2.5, 3.1] and 1.1: 95% CI[1.0, 1.2], respectively, and the mean volume of epinephrine injected was 19.9 mL: 95% CI[19.3 mL, 20.5 mL]. The rate of recurrent bleeding in the combination group (2/44, 4.5%) was significantly lower in comparison with the injection group (9/44, 20.5%, p < 0.05). The mean number of therapeutic endoscopic sessions needed to achieve permanent hemostasis in the combination group (1.04: 95% CI[1.01, 1.07]) was significantly lower vs. the injection group (1.22: 95% CI[1.15, 1.30]). CONCLUSIONS: The combination of an endoscopic mechanical method of hemostasis plus epinephrine injection is more effective than epinephrine injection alone for the treatment of bleeding peptic ulcer.

Epinephrine↗
PubMed2003

Endoscopic hemostasis: safe treatment for peptic ulcer patients aged 80 years or older?

BACKGROUND AND AIM: Recently, the number of peptic ulcer patients aged 80 years or older has been increasing. However, little information is available concerning therapeutic endoscopy for these patients. The objective of this study was to evaluate the efficacy of endoscopic hemostasis for peptic ulcer bleeding in patients aged 80 years or older. METHODS: In this 7-year study, bleeding peptic ulcer patients were divided into group A (>/=80 years old) and group B (<80 years), for which prospective data, endoscopic findings and outcomes of endoscopic treatment were compared. RESULTS: Of the 459 patients who underwent endoscopic hemostasis for peptic ulcer bleeding, the 42 patients (average age 84 +/- 3 years) in group A had a significantly higher incidence of concomitant disease, lower hemoglobin, transfusional requirement over 800 mL and lower serum albumin than the 417 patients (average age 55 +/- 13 years) in group B. Significantly more patients in group A had large gastric ulcers. More patients in group A had ulcers located at the proximal third of the stomach, which is technically difficult to treat endoscopically. Nevertheless, all patients in groups A and B underwent initial hemostasis successfully. The rebleeding rate was not significantly different between group A and B. Neither group had hospital deaths nor complications related to endoscopic procedures. CONCLUSIONS: Endoscopic hemostasis for peptic ulcer bleeding in patients aged 80 years or older is effective and safe. Increasing age may no longer be a risk factor for rebleeding and hospital death after endoscopic hemostasis for peptic ulcer bleeding.

Aged↗
PubMed1976

Alterations of hemostasis associated with cardiopulmonary bypass: pathophysiology, prevention, diagnosis, and management.

This chapter has provided a review of available literature regarding alterations of hemostasis associated with CPB. The primary pathology of altered hemostasis during CPB appears to be two-fold: (1) a functional platelet defect of unclear etiology, which occurs in virtually all patients, and (2) a primary hyperfibino(geno)lytic defect which occurs in the majority of patients undergoing cardiopulmonary bypass. Significant thrombocytopenia does not appear to be a consistent problem, and is probably a function of perfusion technics; this may, however, be an important source of hemorrhage in some instances. Although hyperheparinemia, heparin rebound, and protamine excess have occasionally been incriminated as sources of hemorrhage during CPB, no well documented cases appear in the literature. Likewise, although DIC gained popularity in early reports of CPB hemorrahge, it appears that this syndrome rarely, if ever, arises as a consequence of CPB alone; it can be seen, however, in CPB patients who are provided a triggerin situation for DIC, such as shock, sepsis, or hemolytic transfusion reaction. It is likely that many reported alterations of hemostasis during CPB which were concluded to represent DIC actually were due to hyperfibino(geno)lysis. The key to prevention of CPB hemorrhage rests simply in obtaining an adequate preoperative workup. Of extreme importance is an adequate history with respect to bleeding tendencies in both patient and family; of equal importance is a careful history regarding antiplatelet drugs. A careful physical examination, searching for clues of a real or potential bleeding diathesis, also can often prevent catastrophic cases of CPB hemorrhage. Lastly, an adequate presurgical laboratory screen must be performed; in addition to the usual prothrombin time, partial thromboplastin time, and platelet count, a thrombin time and standardized template bleeding time must be added. The addition of these two simple modalities will insure against significant defects in fibrinogen, the fibrinolytic system, vascular function, and platelet function. When CPB hemorrhage occurs, simple laboratory screening will usually allow for a quick hemostasis evaluation. The parameters recommended in this review will distinguish between surgical and nonsurgical bleeding and should, therefore, allow for a quick decision regarding necessity for reexploration and the adequacy of hemostasis if reexploration is needed. In addition, this screen will distinguish between difficulties with heparin, protamine, and the fibrinolytic system. The vast majority of nonsurgical hemorrhages during CPB is due to a functional platlet defect, primary hyperfibrino(geno)lysis, or a combination of these. The quick administration of platelet concentrates, while awaiting laboratory evaluation, will control or significantly blunt most instances of CPB hemorrhage. If platelets fail to control bleeding, and reasonable laboratory evidence of primary hyperfibrino(geno)lysis is present, antifibrinolytics should then be used...

Blood Coagulation Factors↗
PubMed1986

Current status of argon laser hemostasis of bleeding ulcers.

Endoscopic argon laser photocoagulation has been extensively studied in animals. Clinical pilot studies and randomized controlled trials have demonstrated that argon laser endoscopic hemostasis is both safe and efficient. Specific guidelines for successful endoscopic hemostasis have been determined. The limitations of the argon laser for emergency hemostasis are a strong absorption by blood, its expense and lack of portability, the inability to tamponade or to treat tangentially, and the vaporization potential. The Nd:YAG laser shares all these limitations except that it is less absorbed by blood. Because of these limitations, GI lasers are at present being used less for emergency hemostasis than for elective tumor ablation. Some new, non-laser, thermal devices which do not have these limitations have been developed. They are currently being evaluated in randomized trials. Perhaps because of these factors, the good results obtained with lasers for emergency hemostasis of bleeding ulcers have not been translated into clinical practice at most hospitals.

Argon↗
PubMed2001

A novel collagen-based composite offers effective hemostasis for multiple surgical indications: Results of a randomized controlled trial.

BACKGROUND: Intraoperative bleeding is ubiquitous during open surgical procedures and uniformly effective hemostasis remains elusive. We conducted a randomized controlled trial to determine the effectiveness of a novel collagen-based composite (CoStasis Surgical Hemostat) compared with standard methods of hemostasis during general, hepatic, cardiac, and orthopedic operations. METHODS: Hemostatic treatment was assigned randomly to 347 subjects; 318 subjects (167 CoStasis, 151 controls) underwent operation, received treatment, and provided hemostatic success data. CoStasis was applied to the bleeding site without manual pressure as a sprayable liquid composite of bovine microfibrillar collagen, bovine thrombin, and autologous plasma. Manual compression was used as the control hemostat. Hemostatic success was achieved if bleeding had ceased completely within 10 minutes (3 minutes for cardiac subjects). The time to controlled bleeding (ie, slight oozing) and time to complete hemostasis were recorded for all subjects. RESULTS: Hemostatic success was achieved in more than 90% (153/167) of CoStasis subjects compared with 58% (88/151) of control subjects (P =.01). Superior hemostatic effectiveness with CoStasis was realized in every surgical specialty: general (77/79 vs 49/75, P =.01), hepatic (38/39 vs 20/29, P =.01), cardiac (28/37 vs 17/37, P =.02), and orthopedic (10/12 vs 2/10, P =.01). The duration of bleeding was also significantly shorter with CoStasis. The median time to controlled bleeding (42 seconds vs 150 seconds, P =.0001) and time to complete hemostasis (75 seconds vs 252 seconds, P =.0001) were both markedly longer with the control intervention. There were no serious adverse events related to the use of CoStasis. CONCLUSIONS: CoStasis is more effective at controlling and stopping diffuse intraoperative bleeding than standard methods of hemostasis in 4 distinct surgical indications representing a wide variety of operative interventions.

Adult↗
PubMed2000

Comparison of poly-N-acetyl glucosamine (P-GlcNAc) with absorbable collagen (Actifoam), and fibrin sealant (Bolheal) for achieving hemostasis in a swine model of splenic hemorrhage.

OBJECTIVE: To compare the hemostatic capabilities of poly-Nacetylglucosamine (p-GlcNAc) with three currently available products: Actifoam, Surgicel, and Bolheal fibrin glue. This study was conducted in a controlled animal model, with monitoring of hematologic parameters over the course of the study. Two series were conducted, one in unheparinized animals comparing Bolheal fibrin sealant, Actifoam (absorbable collagen, AC), and Surgicel (ORC) with p-GlcNAc, and the second in systemically heparinized animals comparing p-GlcNAc with AC. METHODS: This study was performed in immature female Yorkshire White swine. Splenic lacerations controlled for length and depth of wound were used as sources of bleeding, with one material used per wound to assess hemostatic effectiveness. A total of 97 wounds in 12 animals were created for the study, 74 wounds in unheparinized animals, and 23 wounds in the heparinized animals. In the heparinized animals, hemostatic efficacy was judged by number of applications needed to achieve complete hemostasis. In the unheparinized animals, hemostatic efficacy was judged by length of time required to achieve complete hemostasis (p-GlcNAc vs. fibrin sealant) or the number of applications needed to achieve complete hemostasis (p-GlcNAc vs. AC or ORC). RESULTS: In systemically heparinized animals, p-GlcNAc demonstrated greater hemostatic efficacy (72.7 %) in one application than did the control material (0%), p < 0.01. In the unheparinized animals, p-GlcNAc took less time to achieve hemostasis (mean, 22.9 seconds) than fibrin sealant (mean, 172.9 seconds), p < 0.01. p-GlcNAc achieved hemostasis with a greater efficacy (79.2%) in one application than did the AC or ORC (16.7%), p < 0.01, whereas there was no difference in the efficacy of the control materials. CONCLUSION: The results of the previous series in unheparinized animals demonstrated that p-GlcNAc in the form of a membrane is a more effective topical hemostatic agent than Bolheal fibrin glue, AC or ORC. The results in the anticoagulated animals similarly demonstrate that p-GlcNAc is a more effective topical hemostatic agent than the control material AC. These data indicate that p-GlcNAc is a promising hemostatic agent as evaluated in this model.

Acetylglucosamine↗
PubMed2006

Factors associated with failure of initial endoscopic hemoclip hemostasis for upper gastrointestinal bleeding.

BACKGROUND: Endoscopic hemoclip is widely used for the management of bleeding peptic ulcers. The major difficulty in clinical application of the hemoclip is deployment to the lesion during initial hemostasis. The aim of this study was to define factors associated with the failure of endoscopic hemoclip for initial hemostasis of upper GI bleeding. PATIENTS AND METHODS: From January to December 2003, we prospectively studied 77 randomized patients with clinical evidence of upper GI bleeding due to either active bleeding or a visible vessel identified by upper GI endoscopy in our emergency department. RESULTS: Among the 77 patients, 13 (16.9%) failed treatment (Group 1) and 64 (83.1%) were successfully (Group 2) treated by endoscopic hemoclip for lesions related to upper GI bleeding. There were no differences due to gender, blood pressure, initial heart rate, and hemoglobulin before or after endoscopic treatment, platelet count, serum creatinine, and albumin between groups. The mean age of Group 1 was higher than that of Group 2 (73.31+/-9.38 years vs. 65.41+/-16.45 years, respectively; P=0.083). Most patients who did not achieve initial hemostasis by endoscopic hemoclip had upper GI lesions over the gastric antrum and duodenal bulb. Among the 13 patients who failed to achieve endoscopic hemoclip initial hemostasis, four lesions were located over the posterior wall of the antrum, and four lesions over the lesser curvature side of the duodenal bulb. CONCLUSION: Endoscopic hemoclip is an effective hemostatic method for upper GI bleeding. Age, gastric antrum, and duodenal bulb lesions may be associated with the failure of initial hemostasis by endoscopic hemoclip.

Aged↗
PubMed2000

Genetic determinants of hemostasis phenotypes in Spanish families.

BACKGROUND: Recent studies have described genetic mutations that affect the risk of thrombosis as a result of abnormal levels of such hemostatic parameters as protein C, protein S, and the activated protein C resistance ratio. Although these mutations suggest that genes play a part in determining variability in some hemostasis-related phenotypes, the relative importance of genetic influences on these traits has not been evaluated. METHODS AND RESULTS: The relative contributions of genetic and environmental influences to a panel of hemostasis-related phenotypes were assessed in a sample of 397 individuals in 21 extended pedigrees. The effects of measured covariates (sex, age, smoking, and exogenous sex hormones), genes, and environmental variables shared by members of a household were quantified for 27 hemostasis-related measures. All of these phenotypes showed significant genetic contributions, with the majority of heritabilities ranging between 22% and 55% of the residual phenotypic variance after correction for covariate effects. Activated protein C resistance ratio, activated partial thromboplastin time, and Factor XII showed the strongest heritabilities, with 71.3%, 83.0%, and 67.3%, respectively, of the residual phenotypic variation attributable to genetic effects. CONCLUSIONS: These results clearly demonstrate the importance of genetic factors in determining variation in hemostasis-related phenotypes that are components of the coagulation and fibrinolysis pathways and that have been implicated in risk for thrombosis. The presence of such strong genetic effects suggests that it will be possible to localize previously unknown genes that influence quantitative variation in these hemostasis-related phenotypes that may contribute to risk for thrombosis.

Adolescent↗
PubMed2003

Hemostasis and hemodilution: a quantitative mathematical guide for clinical practice.

UNLABELLED: Quantitative changes of hemostasis during hemodilution remain unclear. With the increasing popularity of artificial blood substitutes (ABS), which solely provide oxygen-transport capacity, this issue becomes even more complex. We developed a mathematical model to quantitatively analyze hemostasis during hemodilution and validated it by recalculating patient data. We calculated and compared maximal allowable blood losses (MABL) related to minimal acceptable hematocrit, platelet concentration, and plasma fibrinogen concentration. MABL is the maximal blood loss that can be tolerated without any additional blood products. The variable with the smallest MABL thus limits hemodilution foremost. Hemodilution included isovolemic replacement of blood loss with colloid or acute normovolemic hemodilution (ANH) followed by isovolemic replacement of blood loss with colloid and ABS. We also related our findings to preoperative patient data (n = 204). The decline in platelet concentrations rarely (<2% of all patients) limits hemodilution. By contrast, critical plasma fibrinogen (< or =100 mg/dL) concentrations can often (< or =20% of all patients) limit hemodilution if their initial concentrations are within the lower normal range (<300 mg/dL). These findings become more frequent if ANH is combined with ABS. Under those circumstances ANH blood products are solely required for stabilization of hemostasis, thereby defeating the original purpose of combining ANH with ABS. IMPLICATIONS: The causes of quantitative changes of hemostasis during hemodilution, as well as their clinical effect and relevance, remain unclear. Using a validated, realistic mathematical model, we demonstrate that hemostasis, especially plasma fibrinogen, can limit the extent of hemodilution. This phenomenon is particularly prominent when acute normovolemic hemodilution is combined with artificial blood substitutes.

Blood Loss, Surgical↗
PubMed1999

[Liver diseases and hemostasis].

The liver plays a key role in the regulation of hemostasis. By producing most clotting factors and inhibitors, as well as a number of the proteins involved in fibrinolysis, and by clearing from the bloodstream activated enzymes involved in clotting or fibrinolysis, the liver protects against both bleeding and undue activation of coagulation. It follows that liver diseases are commonly responsible for hemostasis abnormalities including decreased production of clotting factors, thrombocytopenia, platelet dysfunction, and increased circulating fibrinolytic activity. With the exception of cholestasis and in the absence of a specific setting such as pregnancy, the abnormalities are the same in all liver diseases, and their severity varies only with the degree of hepatocellular failure. Although liver diseases do not directly cause disseminated intravascular coagulation (DIC), they are a major risk factor for DIC in patients with infection or shock, as well as during pregnancy. In patients with liver diseases, hemostasis tests can be required to evaluate the degree of hepatocellular failure, the severity of hemostasis disorders manifesting as bleeding, or the bleeding risk before an invasive procedure. Prothrombin time determination is usually sufficient to evaluate the degree of hepatocellular failure, although in some cases assays of fibrinogen and factors II, VII, X, V are also useful. Evaluation of the bleeding risk prior to an invasive procedure requires a study of platelet function and measurement of circulating fibrinolytic activity, which is particularly likely to be abnormal in patients with severe hepatocellular failure and/or alcohol abuse. A less common reason for investigating hemostasis is a search for the cause of a thrombotic condition, such as portal vein thrombosis or Budd-Chiari syndrome.

Blood Coagulation Disorders↗