Evaluation Of Prothrombin Time Research Articles

Evaluation of Prothrombin Time and Activated Partial Thromboplastin Time in Native and Citrated Whole Blood in Hispaniolan Amazon Parrots (Amazona ventralis) With a Handheld Point-of-Care Analyzer.

Objective assessment of coagulation in birds is difficult, and traditional methods of measuring prothrombin time (PT) and activated partial thromboplastin time (aPTT) with the use of mammalian reagents have not been validated in birds. Avian-specific reagents must be prepared from brain extract and are not practical for clinical use. The objective of this investigation was to determine whether the InSight qLabs point-of-care analyzer (Micropoint Biotechnologies Inc, Guangdong, China) could measure PT and aPTT in Hispaniolan Amazon parrots (Amazona ventralis) in native and citrated whole blood, and whether the values obtained correlated with clinical appearance and basic hematologic and biochemical parameters from the bird. The qLabs analyzer was able to measure aPTT reliably, but not PT. Activated partial thromboplastin time of citrated blood was significantly different from the aPTT measured from native whole blood (P < 0.001). On the basis of this study, the qLabs machine may be used to measure aPTT, but clinical application between avian species requires further research.

Hemoglobin-Based Oxygen Carrier for the Reconstitution of Canine Freeze-Dried Plasma in an In Vitro Model of Resuscitation.

Military working dogs (MWDs) are force multipliers that are at risk for severe trauma when employed on the battlefield. When in severe hemorrhagic shock, MWDs require both oxygen- carrying capacity and replacement of vascular volume and coagulation factors. The objective of this study was to evaluate the hemostatic capacity of canine freeze-dried plasma (cFDP) with a Food and Drug Administration (FDA)-approved hemoglobin- based oxygen carrier (HBOC) in an in vitro model of resuscitation. Whole blood (WB) was collected from 10 MWDs, and these samples were diluted by 10%, 25%, or 40% with either cFDP (reconstituted with water), HBOC, cFDP (reconstituted with HBOC), or an equal volume of a 1:1 ratio of cFDP (reconstituted with water) and HBOC. Hemostatic parameters were minimally changed based on evaluation of prothrombin time, activated partial thromboplastin time, fibrinogen and thromboelastography at the 10% and 25% dilutions, and parameters consistent with a hypocoagulability were seen at dilutions of 40%. Based on the results of this study, additional research is warranted to determine if cFDP reconstituted with HBOC is a viable resuscitation product in canine trauma.

Evaluation of Prothrombin time and Activated Partial Thromboplastin Time Tests in Diabetes Mellitus Patients at Meru Teaching and Referral Hospital

Evaluation of Prothrombin time and Activated Partial Thromboplastin Time Tests in Diabetes Mellitus Patients at Meru Teaching and Referral Hospital

Impact of some intravenously administered drugs (paracetamol, hydrocortisone, dexamethasone and amikacin) on coagulation hemostasis (in vitro evaluation study)

Background:Normally, the coagulation homeostasis prevents bleeding and retain the blood in the vascular system during periods of injury. Unfortunately, pathological factors, drugs or toxins could affect one or more stages of homeostasis mechanisms leading to bleeding or abnormal thrombi. Evaluation of prothrombin time is a favorable test for the screening of extrinsic coagulation mechanism whilst activated partial thromboplastin time measurement is a global coagulation screening method for intrinsic factor.Material and Methods:Blood samples were withdrawn from healthy adults volunteers for clotting times measurements from collected plasma. The effect of paracetamol, hydrocortisone, dexamethasone, and amikacin at different concentrations on coagulation homeostasis was in vitro investigated and compared to control and positive control.Results:High concentrations of all tested drugs except amikacin prolong significantly activated partial thromboplastin time, whilst the effect on the prothrombin time was conflicting.Conclusions:Paracetamol, hydrocortisone, dexamethasone, and amikacin could prolong clotting time expressed in prolongation of activated partial thromboplastin time comparable to the anticoagulants drugs.

Preoperative assessment of haemostasis in patients undergoing stereotactic brain biopsy

Parenchymal hemorrhage is considered a major risk factor for perioperative morbidity in patients undergoing stereotactic brain biopsy. Studies on patients undergoing surgical procedures have suggested that evaluation of prothrombin time (PT) and activated partial thromboplastin time (aPTT) is of limited value with regard to prevention of haemorrhagic complications. However, this issue has not yet been addressed in patients undergoing stereotactic biopsy of intracranial lesions. We retrospectively analysed the medical records of 159 consecutive patients undergoing stereotactic biopsy of supratentorial intracranial lesions during a three-year period. Laboratory values (PT, aPTT, platelet count) were reviewed as well as clinical characteristics, modalities of surgical treatment, histopathological results and the postoperative course of patients. The overall diagnostic yield was 93.7%. Histopathological examination revealed glioma (WHO°I: 5, WHO°II: 25, WHO°III: 23, WHO°IV: 65), lymphoma (n = 14), inflammation (n = 8) and other entities (n = 6). Surgery-associated neurological deficits occurred in 7 patients (4.4%) and completely resolved in 6 of these patients. CT-confirmed intracranial hemorrhage occurred in 2 patients (1.3%) and in both cases, histopathological examination revealed glioblastoma. Results of hemostatic parameters (PT: 99 ± 13%, aPTT: 24 ± 3s, platelet count: 274 ± 87 103/μL) were within normal range values in all patients and did not correlate with postsurgical morbidity. Standard assessment of haemostasis seems to be of limited value in patients with intracranial lesions undergoing stereotactic biopsy. Further studies regarding the intratumoural vasculature’s impact on the risk of biopsy-related bleeding are necessary.

Evaluation of Prothrombin Time and Activated Partial Thromboplastin Time among Patients with Obstructive Jaundice in Federal Medical Center Yola, Nigeria

Evaluation of Prothrombin Time and Activated Partial Thromboplastin Time among Patients with Obstructive Jaundice in Federal Medical Center Yola, Nigeria

Evaluation of Prothrombin Time in Acute Acetaminophen Overdose treated by N-acetylcysteine

Background: Acetaminophen (N-Acetyl-p aminophenol; APAP) is one of the most common types of analgesics. It is also the most common xneobitic reported to poison centers. This study investigates if therapeutic doses of NAC can falsely increase coagulation tests, prothrombin time (PT) and bleeding time (BT). ​​ Methods: Thirty-six APAP poisoned patients whose acetaminophen serum concentration were in toxic zone in the Rummak-Matheiw graph were treated by NAC according to standard intravenous 21 hours protocol. Prothrombin time (PT) and bleeding time (BT) in all cases were measured before the start of the NAC and at the 8th and 16th hour of the treatment. Results: The mean age of the cases was 21.5 ± 5.12 years old. Among them, 31 cases (86%) were female. The mean dose of ingested APAP was 9.6 ±2.0 grams (7.8 – 16.1 g). Mean of SLA was 196.0±37.7. The means of BT were nor significantly different at all evolution times (2.6±0.64, 2.6±0.62 and 2.6± 0.6. The means of PT rose at 16th hour of NAC treatment in as compared 8th hour (16.1± 1.1 s 12.3±0.6 s, respectively) (P <0.001). Conclusion: With specific reference to our study results, a low level of rising PT resulting from an NAC treatment is not a reliable indicator of liver damage. Further investigation on the effect of NAC on clotting factors is recommended.

Evaluation of prothrombin time and activated partial thromboplastin time mixing studies using an estimated factor correction method.

Mixing studies for prolonged prothrombin time (PT)/activated partial thromboplastin time (aPTT) are used to estimate whether the prolongation is due to an inhibitor or factor deficiency. We propose a new method of mixing study interpretation based on estimation of average factor level changes. Factor level vs. PT/aPTT curves were prepared for single factor, vitamin K-dependent factor, and all factor deficiencies. These curves were used to predict the factor level in the sample and the correction needed to differentiate deficiencies from inhibitors. We compared this estimated factor correction (EFC) method to normal range, percentage correction, and Rosner index. For a given factor level, multiple factor deficiencies prolonged the PT/aPTT more than single factor deficiency, necessitating different thresholds for defining correction on mixing studies. The EFC method was superior to other the correction methods, correctly identifying 38 of 39 known inhibitors, single and multiple factor deficiencies, and correctly identifying inhibitor vs. deficiency in 50 of 59 patient samples. In 99 adult patient mixing studies over 18 months, 30% showed deficiency only, 30% inhibitor only, whereas 40% showed evidence of both. The EFC method for PT/aPTT mixing study interpretation was more accurate than the comparison methods at determining deficiency versus inhibitor.

Evaluation of prothrombin time and activated partial thromboplastin time in hypertensive patients attending a tertiary hospital in calabar, Nigeria.

Introduction. Several biomedical findings have established the effects of hypertension on haemostasis and roles of blood coagulation products in the clinical course of hypertension. Methods. This cross-sectional study aimed at determining effects of hypertension on prothrombin time (PT) and activated partial thromboplastin time (APTT) in hypertensive patients in comparison with normotensive subjects attending a tertiary hospital in Calabar. Forty-two (42) hypertensive patients and thirty-nine (39) normotensive control subjects were investigated for PT and APTT using Quick one-stage methods. Results. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) correlated positively with APTT (r = 0.3072, r = 0.4988; P < 0.05) in hypertensive patients. DBP, SBP, PT, and APTT were significantly higher in hypertensive patients when compared to normotensive subjects (P < 0.05). DBP correlated negatively with duration of illness (r = −0.3097; P < 0.05) in hypertensive patients and positively with age of normotensive subjects (r = 0.3523; P < 0.05). Conclusion. The results obtained indicated that measurements of PT and APTT may serve as indices for evaluating hemostatic abnormalities in hypertensive patients and guide for antihypertensive therapy. However, to have better understanding of hemostatic activities in hypertension, it is recommended to conduct D-dimer, platelet factors, and protein assays.

Variceal hemorrhage: Saudi tertiary center experience of clinical presentations, complications and mortality

To determine the clinical presentation, underlying etiology and short- and long-term outcomes of acute variceal bleeding (AVB). A retrospective descriptive cohort study of cirrhotic patients with AVB who were admitted to King Abdul Aziz University Hospital between January 2005 and December 2009. We obtained demographic data for all patients. For each patient we also obtained the clinical data at presentation; cause of liver cirrhosis, bleeding presentation (hematemesis and/or melena), presence of ascites, hepatic encephalopathy and renal impairment (RI) or hepatorenal syndrome. We carried out complete blood count, prothrombin time evaluation, and liver function tests. We also report all episodes of re-bleeding after the first episode of AVB, both during the initial admission and after discharge. We recorded the length of stay for each patient and thereby calculated the mean duration of stay for all patients. The length of follow-up after the first AVB and the outcome for each patient at the end of the study period were recorded. Causes of mortality either related to liver disease or non-liver disease cause were determined. A 125 patients were enrolled in the study. The number of episodes of AVB for each patients varied between 1 and 10. Survival from the first attack of AVB to death was 20.38 mo (SD 30.86), while the length of follow-up for the living patients was 53.58 mo (SD 24.94). Total number of AVB admissions was 241. Chronic hepatitis C, the commonest underlying etiology for liver disease, was present in 46 (36.8%) patients. Only 35 (28%) patients had received a primary prophylactic β-blocker before the first bleeding episode. The mean hemoglobin level at the time of admission was 8.59 g/dL (SD 2.53). Most patients had Child-Pugh Class C 41 (32.8%) or Class B 72 (57.6%) disease. Hematemesis was the predominant symptom and was found in 119 (95.2%) patients, followed by melena in 75 (60.0%) patients. Ascites of variable extent was documented in 93 (74.4%) patients. We identified hepatic encephalopathy in 31 (28.8%) patients and spontaneous bacterial peritonitis in 17 (13.6%). Bleeding gastric varices was the cause of AVB in 2 patients. AVB was associated with shock in 22 patients, 13 of whom (59.1%) had Child-Pugh class C disease. RI was noted in 19 (46.3%) of 41 patients in Child-Pugh class C and 14 (19.4%) of 72 patients in Child-Pugh class B. None of the patients with Child-Pugh class A disease had RI. Emergency endoscopy was effective in controlling the bleeding, although the re-bleeding rate was still high, 12 (9.6%) during the same admission and 55 (44%) after discharge. The re-bleeding rate was higher in patients with ascites, occurring in 40/55 (72.2%). The length of hospital stay was 1-54 d with a mean of 8.7 d. Three patients had emergency surgery due to failure of endoscopic treatment and balloon tamponade. The overall long term mortality was 65%. Survival from the first attack of AVB to death was 20.38 ± 30.86 mo, while the length of follow-up for the living patients was 53.58 ± 24.94 mo. Patients with Child-Pugh score C had a higher risk of liver disease-related mortality (67.6%). RI (developed during admission) was the main factor that was associated with mortality (P = 0.045). The majority of patients with liver disease who present at the emergency unit for AVB are at an advanced stage of the disease. The outcome is poorer for patients who develop RI during hospitalization.

Comparison of prothrombin time evaluation using automated and bedside devices in cancer patients

Comparison of prothrombin time evaluation using automated and bedside devices in cancer patients

Brodifacoum Poisoning of Avian Scavengers During Rat Control on a Seabird Colony

Langara Island, at the north-western tip of British Columbia's Queen Charlotte archipelago, was once nesting grounds for an estimated 500,000 seabirds. However, infestations of Norway rats (Rattus norvegicus) and their predation of eggs and breeding adults have caused extirpation or serious declines of all seabird species. By 1993, the breeding population of ancient murrelets (Synthliboramphus antiquus) had declined to 10% of its historical size. Successful eradication of rats on smaller New Zealand islands using the anticoagulant brodifacoum prompted its application on Langara Island. The island is also home to breeding bald eagles (Haliaeetus leucocephalus), peregrine falcons (Falco peregrinus), and other wildlife. No comprehensive studies of non-target impacts and potential for secondary poisoning were done during similar operations elsewhere; thus, in 1994 and 1995 we initiated a two-year study into the risk of secondary poisoning to non-target species. During 1994, rat carcasses were laid out with motion sensor cameras to identify potential scavengers. Ravens, northwestern crows and bald eagles were photographed at carcasses, and therefore at risk of feeding on rats that die above ground. During the baiting program, 19 rats were radio-tagged to determine the proportion dying above ground, and thus available to predators/scavengers. Ravens were found poisoned both from feeding directly on the bait, and predating/scavenging poisoned rats. Bald eagles were trapped and blood sampled for brodifacoum residue analysis and prothrombin time evaluation; 15% of the sampled population showed detectable residues but no adversely-affected birds were found. We conclude that the use of brodifacoum for rat removal on seabird islands poses a clear risk of secondary poisoning to avian scavengers. This risk must be weighed against the benefit of rat removal programs.

Evaluation of Prothrombin Time with Use of Highly Diluted Tissue Factor Reagent

Prothrombin time (PT) is an established screening method for hemorrhagic disorders. Recent progress of the biochemistry of tissue factor (TF)-dependent coagulation pathway revealed that TF/factor VIIa complex activated factor IX rather than factor X. However, PT does not reflect the activity of factors IX and VIII, because of excess amount of TF reagent in the assay system. In this study, we evaluated PT using highly diluted TF reagent (Dil-PT) and its clinical application. Coexistence of magnesium with calcium ion resulted in the shortening of Dil-PT. Dil-PT prolonged in accordance with the decrease of TF reagent, and prolongation was observed in factor VIII-and factor IX-deficient plasmas similarly to the factor X-, factor V-, factor VII-and factor II-deficient plasmas. On the contrary, prolonged clotting time of factor XI-, factor XII-, high molecular weight kininogen-and plasma prekallikrein-deficient plasmas were the same as that of normal pooled plasma in the Dil-PT system. In the clinical samples, significant shortenings of Dil-PT and PT were observed in the patients with rhabdomyolysis. On the other hand, Dil-PT showed significant shortning in gestational toxicosis, but PT did not. These results suggest that Dil-PT reflect the activity of factors IX and VIII besides factors VII, X, V and II, and Dil-PT is an useful screening method that does not require specific reagents and apparatus for the detection of hypercoagulable state.