Description

The risk of major hemorrhage requiring blood transfusion in a patient receiving thrombolytic therapy following a myocardial infarction can be estimated using a predictive instrument.


 

Parameters for score:

(1) age

(2) sex

(3) history of hypertension

(4) systolic blood pressure

(5) heart rate with systolic blood pressure

(6) sex with dose of thrombolytic agent adjusted for weight

(7) standard dose of thrombolytic agent adjusted for weight

Parameter

Finding

Value

age

< 30 years

0

 

30 - 75 years

age in years

 

> 75 years

75

sex

female

0

 

male

1

history of hypertension

absent

0

 

present

1

systolic blood pressure

< 60 mm Hg

60

 

60 - 190 mm Hg

systolic blood pressure

 

> 190 mm Hg

190

heart rate with systolic BP

systolic BP < 100 mm Hg, AND heart rate < 40 beats/min

15

 

systolic BP < 100 mm Hg, AND heart rate >= 40 and <= 55 beats/min

55 - (heart rate)

 

systolic BP >= 100 and <= 120 mm Hg, AND heart rate < 40 beats/min

15 * (120 - (systolic BP)) / 20

 

systolic BP >= 100 and <= 120 mm Hg, AND heart rate >= 40 and <= 55beats/min

(55 - (heart rate)) * (120 - (systolic BP)) / 20

 

systolic BP > 120 mm Hg, OR heart rate > 55 beats/min

0

standard dose of thrombolytic agent adjusted to weight

70 * (standard dose) / (weight) < 0.7

0

 

70 * (standard dose) / (weight) >= 0.7 and <= 1.4

(70 * (standard dose) / (weight)) - 0.7

 

70 * (standard dose) / (weight) > 1.4

0.7

sex with standard dose of thrombolytic agent adjusted to weight

female

0

 

male

standard dose adjusted to weight (see previous parameter)

 

number of standard doses for tissue plasminogen activator (TPA) =

= (number of units) / 100

 

number of standard doses for streptokinase =

= (number of units) / (1.5 million)

 

number of standard doses for urokinase =

= (number of units) / (1 million)

 

score =

= (0.0378 * (value for age)) - (0.3919 * (value for sex)) + (0.8017 * (value for hypertension history)) - (0.0246 * (value for systolic blood pressure)) + (0.2181 * (value for heart rate and systolic BP)) + (4.1339 * (standard dose of thrombolytic agent adjusted for weight)) - (3.0338 * (value for sex with standard dose adjusted for weight)) - 3.3296

 

probability of major hemorrhage =

= 1 / (1 + EXP((-1) * (score)))

 


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