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Heparin 

Indication

Bolus dose
(Units/kg)

Maximum bolus
(Units)

Initial infusion
U/kg/h

Maximum
Initial infusion rate
U/kg/h

80

80

70

60

10,000

5,000

5,000

4000

18

18

15

12

1,800

1,000

1,200

1,000

Body Weight 

kg.

Bolus

Units

Initial infusion

Heparin 2ml (10,000 U) + NSS 100 ml (100 Units/ml)

IV drip 

ml/h

(                 Units/kg/h)

Adjustment

aPTT ratio

Repeated bolus dose
(Units)

Stop infusion
duration
(min)

Change rate of infusion

Time to next aPTT (hours)

>7

-

180

Reduce rate by 500 U/h (5ml/h)

3

5.1-7.0

-

60

Reduce rate by 500 U/h (5ml/h)

6

4.1-5.0

-

30-60

Reduce rate by 300 U/h (3ml/h)

6

3.1-4.0

-

30-60

Reduce rate by 200 U/h (2ml/h)

6

2.6-3.0

-

30-60

Reduce rate by 100 U/h (1ml/h)

6

1.8-2.5

-

0

No change

Next morning

1.2-1.7

2,500

0

Increase rate by 100-200 U/h (1-2 ml/h)

6

<1.2

5,000

0

Increase rate by 400 U/h (4 ml/h)

6

Monitoring

Vital signs (BP, HR, RR)

  • Observe neurological sign

  • Observe bleeding

  • Lab

  • PTT keep <70 sec,

  • aPTTratio (keep < 2.5) q 4-6 h

  • platelet, Hct q 2 days

  • ตรวจสอบปริมาณยาที่เหลือตามแผนการรักษา

Notify if...

  • Neurological sign change

  • PTT >/= 70 sec

  • aPTT ratio > 2.5

  • Platelet < 100,000 /mm3

  • Hct drop > 3% from baseline

  • invasive catheter bleeding/hematoma

  • heparin infusion pump error

  • Antidote: Protamine 1 - 1.5mg/100U of heparin (25-50 mg, Maximum 50 mg) slow injection in 10 minutes

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