Question

The patient weighs 255 pounds. On admission, the patient's aPTT is 30 seconds. You initiate IV heparin therapy at 1730 on 12/10/20. The infusion pump is calibrated to deliver whole mL/h.  

Heparin IV infusion: Heparin 50,000 units in 500 mL of 1/2 NS. IV Boluses: Use 1000 units/mL. Calculate the patient weight to nearest 10 kg. Bolus with 80 Units/kg. Then initiate heparin drip at 18 units/kg/h.

Obtain aPTT every 6 hours, and adjust dosage and rate as follows.     

If aPTT is less than 35 seconds: Rebolus with 80 units/kg and increase rate by 4 units/kg/h.

If aPTT is 35 to 44 seconds: Rebolus with 40 units/kg and decrease rate by 2 units/kg/h.

If aPTT is 45 to 75 seconds: Continue current rate

If aPTT is 76 to 90 seconds: Decrease rate by 2 units/kg/h.

If aPTT is greater than 90 seconds: Hold heparin for 1 hour and then decrease rate by 3units/kg/h.

Calculate the initial heparin bolus dosage:_____________ units

Calculate the bolus dose_____________ml

Calculate the initial heparin infusion rate___________units/hr, or ______________ml/h

At 2330, the patient's aPTT is 40 seconds. According to the protocol what will be your action be?

Rebolus with _______________units or ____________ml

decrease infusion rate by_______________units/hr or ___________ml/hr

for a new rate of______________ml/hr

Answer 1

ANSWER :

•Patient weight : 255 pounds = 116 kg

•Weight to nearest 10 kg = 120 kg

•IV blouses = 1000 units/ml

•Bolus = 80 units/kg

1kg --------> 80 units

120 kg --------> ??

= ( 120 × 80 ) ÷ 1 = 9600 units

1000 units --------> 1ml

9600 units ---------> ??

= ( 9600 × 1 ) ÷ 1000 = 9.6 ml

•Initial heparin bolus dosage 9600 units.

•Initial heparin bolus dose 9.6 ​​​​​​ml.

Heparin IV infusion = Heparin 50000 units in 500 ml 1/2 NS

Heparin drip = 18 units/kg/hr

1kg --------> 18 units

120 kg -------> ??

= ( 120 × 18 ) ÷ 1 = 2160 units

50000 units --------> 500 ml

2160 units -------> ??

= ( 2160 × 500 ) ÷ 50000 = 21.6ml

•Initial heparin infusion rate 2160 units/hr

•​​​​​​Initial heparin infusion rate 21.6 ml/hr

​​​​​​At 2330 patients aptt is 49 sec

So, rebolus with 40 units/kg and decrease rate by 2units/kg/hr

1kg --------> 40 units

120 kg ------- > ??

= ( 120 × 40 ) ÷ 1 = 4800 units

1000 units ------> 1ml

4800 units -------> ??

= ( 4800 × 1 ) ÷ 1000 = 4.8 ml

•Rebolus with 4800 units or 4.8 ml

1kg --------> decrease by 2 units

120 kg ----------> ??

( 120 × 2 ) ÷ 1 = 240 units

50000 units --------> 500 ml

240 units -------- > ??

= ( 240 × 500 ) ÷ 50000 = 2.4 ml

•Decrease infusion rate by 240 units/hr or 2.4 ml/hr.

•New rate of heparin infusion = 21.6 - 2.4 = 19.2 ml/hr.