Wednesday, March 3, 2010
The Olympics of Coagulation-SCORING SYSTEMS: GOING FOR THE GOLD!
While watching the Olympics, I noticed all of the complex scoring systems-
Remember when a 10 was the best you could do? Now they have video replays and different measures of excellence. I thought of the scoring that is used in health care. These systems are used to remove the subjectivity and grade a series of symptoms to help predict outcomes. Now that is golden!
SEVERITY of DISEASE:
APACHE score [a cute p hysiological a ssessment and c hronic h ealth e valuation] a widely-used method for assessing severity of illness in acutely ill patients in intensive care units, taking into account a variety of routine physiological parameters.APACHE II was designed to measure the severity of disease for adult patients (> 15 years of age) admitted to the ICU. .
This scoring system is used in many ways:
- Some procedures and some medicine is only given to patients with certain APACHE II score
- APACHE II score can be used to describe the morbidity of a patient when comparing the outcome with other patients.
- Predicted mortalities are averaged for groups of patients in order to specify the group's morbidity.
The point score is calculated from 12 routine measurements (such as blood pressure, body temperature, heart rate etc.) during the first 24 hours after admission, The resulting point score should always be interpreted in relation to the illness of the patient. In order to make this calculation of predicted mortality precise, the principal diagnosis leading to ICU admission was added as a category weight: the predicted mortality is computed based on the patient's APACHE II score and their principal diagnosis at admission.
Symptoms of deep vein thrombosis (DVT) includes swelling, redness, or pain in the leg that has been present for 60 days or less. While symptoms of pulmonary embolism (PE) includes sudden onset of dyspnea, sudden deterioration of existing dyspnea(s), sudden onset of pleuritic chest pain without another apparent cause.
Patients who present with these symptoms in an outpatient setting can be scored to determine their pre-test probability of having a DVT or PE. Based on their score they will be classified as low, moderate or high probability. The scoring system takes several conditions into consideration.
Data collected for the Wells model for patients suspected of DVT :
- Malignancy (defined as patients with cancer who are receiving treatment or have received treatment in the last 6 months or patients with cancer that are receiving palliative care) (1.0 point)
- Entire leg swollen (1.0 point)
- Paralysis, paresis, or recent plaster immobilization of the lower extremities (1.0 point)
- Immobilized (defined as bed rest, except to access bathroom, for 3 or more consecutive days during the last 30 days) (1.0 point)
- Localized tenderness along the distribution of the deep venous system (1.0 point)
- Calf swelling at least 3 cm larger than on the asymptomatic side (measured 10 cm below the tibial tuberosity) (1.0 point)
- Pitting edema (greater in the symptomatic leg) (1.0 point)
- Previously documented deep-vein thrombosis (1.0 point)
- Collateral superficial veins (nonvaricose) (1.0 point)
- Alternate diagnosis as likely or more possible than that of DVT (-2.0 points)
The patients will be classified into low (0 or less points), moderate (1 or 2 points), or high (3 or more points) probability of DVT during data analysis.
Data collected for the Wells model for patients suspected of PE :
- Clinical signs and symptoms of DVT (3.0 points)
- Heart rate higher than 100 beats/minute (1.5 points)
- Immobilized (defined as bed rest, except to access bathroom, for 3 or more consecutive days during the last 30 days) (1.5 points)
- Previous DVT or PE diagnosis (1.5 points)
- Hemoptysis (1.0 points)
- Malignancy (defined as patients with cancer who are receiving treatment or have received treatment in the last 6 months or patients with cancer that are receiving palliative care) (1.0 points)
- PE as likely or more likely than an alternate diagnosis (3.0 points)
Patients will be classified into low (less than 2 points), moderate (2.0 -6.0 points), or high (higher than 6.0 points) probability of PE during data analysis.Assessment of clinical probability is now widely accepted as an important initial step in the diagnostic approach of pulmonary embolism (PE), as it allows the identification of patients at lower risk of the disease, who require a less extensive diagnostic workup. For instance, the association of a low clinical probability of PE and a low D-dimer concentration has been shown to safely rule out PE.
ISTH Scoring System for Disseminated Intravascular Coagulation
The ISTH recently proposed a scoring system for the diagnosis of DIC based on 4 laboratory parameters and the presence of a predisposing condition. The ISTH algorithm excludes patients without a recognized, predisposing condition at the time of evaluation.
The ISTH defines DIC as "an acquired syndrome characterized by the intravascular activation of coagulation with loss of localization arising from different causes. It can originate from and cause damage to the microvasculature, which if sufficiently severe, can produce organ dysfunction".
DIC is caused by several clinical conditions. The degree is dependent on the etiology and the acuteness.
There are 2 types of DIC: (1) acute hemorrhagic DIC, and (2) chronic or overt DIC.
Acute Hemorrhagic DIC
Acute hemorrhagic DIC develops rapidly-from a few hours to a few days-with a high mortality rate of 54% to 67%. Each patient's presentation varies depending on the etiology and the body's ability to control this coagulopathy. Acute DIC is seen in infections. It is a frequent complication of severe sepsis with a high degree of mortality and multiorgan failure. The disseminated microthrombi decrease tissue oxygenation; this can cause organ infarction and necrosis. It is more likely to occur in conjunction with bacterial infection, in particular gram-negative sepsis. Other causes include obstetric complications, liver malignancy, tissue injury, and necrosis. Excess plasmin formation results in a hemorrhagic state. Patients will present with oozing from sites, large subcutaneous hematomas, deep tissue bleeding, and petechiae. It may occur in patient with endotoxemia, extensive tissue trauma, hypotension or shock, and massive surgery. Treatment depends on the symptoms.
Chronic or Overt DIC
Overt DIC is more difficult to diagnosis than acute DIC, and occurs in 10% to 20% of patients. This is a compensated DIC that occurs when fibrin clot formation and the accompanying fibrinolysis are in a steady state because the liver and bone marrow can compensate for the increased use of coagulation factors and platelets. Additionally, fibrin degradation products (FDPs) can still be cleared. Laboratory tests are minimally abnormal.
Chronic DIC is associated with malignancies, aortic aneurysms, and incomplete abortions. Ten percent to 15% of patients with tumors present with DIC, most likely due to tissue factor expressed on the surface of tumor cells. DIC is also seen in M3-acute promyelocytic leukemia , the granules of the promyelocytes release a thromboplastin-like substance that releases procoagulants.1 Survival in cancer patients with DIC is worse than in cancer patients who do not present with DIC. In these cases, if the underlying disease is appropriately treated, the stimulus for the DIC is removed.
The International Society of Thrombosis and Hemostasis developed a scoring system that improves accuracy in the diagnosis of DIC with 91% sensitivity and 97% specificity. The scoring system follows:
Platelet count: >100=0
<100 = 1
<50 = 2
Fibrin related marker no increase =0
Moderate increase = 2
Strong increase = 3
Prolonged PT <3 sec = 0
>3 sec = 1
>6 sec = 2
Fibrinogen >100 g/dL = 0
<100 g/dL = 1
If the sum is ≥5 the patient status is compatible with overt DIC. It appears to be valid once linked to coagulation activation markers such as the D-dimer and the consumption of inhibitors.
All of these scoring systems have been designed to enhance diagnosis and treatment of patients. They have been developed in relation to outcomes of patients, making them an invaluable tool for clinicians. So, in many cases, it isn't the high score that always wins- but it is the most accurate score that gets the gold!
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