Question

CASE STUDY 2

COPD/Emphysema

A patient is admitted to the hospital with dyspnea and COPD exacerbation. The orders from the physician include:

• Stat ABGs, chest x-ray, complete blood count, and electrolytes
• IV D5W NS 1000 ml/8 hr
• Aminophylline IV loading dose of 5.6 mg/kg over 30 minutes followed by 0.5 mg/kg/hr continuous IV
• O2 at 2 L/min per nasal cannula
• Albuterol respiratory treatments every 4h
• Chest physiotherapy every 4h Erythromycin 800 mg IV every 6h Bed rest Accurate intake/output
• High-calorie, protein-rich diet in six small meals daily
• Encourage PO fluids to 3 L/day

Identify the orders that require calculations.

Set up and solve each problem using dimensional analysis. problem using dimensional analysis.

4. Calculate ml/hr to set the IV pump to infuse erythromycin 800 mg. Erythromycin

supply: 1-g vial to be reconstituted with 20 mL sterile water and further diluted in 250 mL NS to infuse over 1 hr.

5. Calculate the PO fluids in ml/shift for an 8-hour shift.

Answer 1

ANSWERS:-

1) Identify the orders that require calculations:-

a) IV D5W NS 1000ml / 8hr

b) Aminophylline IV loading dose of 5.6mg/kg over 30 minutes followed by 0.5mg/ kg/hr continuous IV.

c) Erythromycin 800mg IV every 6 hr.

d) PO( per oral) fluid to 3L/day.

2) Set up and solve each problem using dimensional analysis:-

a) IV D5W NS 1000ml/ 8hr

* 1000 ÷ 8 =125ml/hr.

b) Aminophylline loading dose of 5.6mg /kg over 30 minutes-

## Patient weight is not given here , so I will do an example-

## If patient weight is 65kg

* Loading dose of Aminophylline = 5.6 × 65;

* 5.6 × 65 = 364mg over 30 minutes.

* Continuous infusion = 0.5 mg/ 65kg/ hr ,

= 0.5 × 65 =32.5 mg /hr .

## Erythromycin and PO fluids will be done in next questions.

3) Calculate ml/hr to set IV pump to infuse Erythromycin 800mg:-

* Erythromycin supply is 1g vial as powder.

* First reconstitute with 20ml of sterile water.

* Now we have Erythromycin 1g / 20ml .

* 1g = 1000mg

* 1000 mg= 20 ml;

• Now take 20ml of reconstituted Erythromycin and add into 250ml NS for further dilution.

* Now we have 270ml .

* Formula for calculation = required dose(800mg) ÷ available dose( 1000mg) × available dilution ( 270ml)

* =800 ÷ 1000 × 270 = 216 ml

* Set IV pump to infuse at 216ml/hr to administer 800 mg of Erythromycin.

4) Calculate PO fluids in ml/shift for an 8- hr shift:-

* Oral fluids iedere = 3L ( 3000ml)

* Amount of fluids for 1hr = 3000 ÷ 24 ( hrs per day)= 125 ml/hr.

* Amount for 8hr = 125 × 8 =1000ml.

* PO fluid ml/ shift = 1000ml.