TPN administration
1. Initiation - TPN solutions should be infused slowly with small increases
in the rate of the first TPN to avoid hyperglycemia.
Start 50 ml/hr x 4 hours,
then 75 ml/hr x 4 hours,
then 100 ml/hr x 4 hours
then increase to final rate.
Blood glucose determinations (accu-chekR) should be done before
each rate increase. If the blood glucose is greater than 200, continue at the
same rate for another 4 hours, check again and if still high, consider insulin
therapy. If patient is diabetic; see section on TPN in various disease states.
2. Cessation - patient can be weaned from TPN rapidly. Decrease the rate by
1/2 every 2 hours until the rate is less than 50 ml/hr, then discontinue.
3. Cyclic TPN administration - Cycling is a procedure used especially in
the outpatient setting to free the patient from being attached to an IV and
allow for ambulation. There are no specific written guidelines on how to
convert patients to cyclic TPN although the following information is generally
considered to be helpful. The patient must be stabilized on the 24 hour
schedule. The maximum hourly rate tolerated for a TPN is usually about 200
ml/hr. Advance to the final time period slowly by subtracting 2-4 hour blocks
of time from the total daily infusion time. It will take several days to reach
the final infusion time. Monitor vital signs, input and output, and glucose
with accuchecks carefully during the change over period as the patient may
require additional time to adjust to new regimen.
To convert a patient from a 24 hour TPN to cyclic TPN the following is
suggested:
Total daily TPN volume/(Total hours to deliver TPN - 1) =
Final cyclic TPN rate
Approximately 1/2 of the final hourly cyclic TPN rate is usually sufficient
for a 1 hour advancing and decreasing taper. Refer to example below. Advancing
tapers at an initial rate exceeding 80 ml/hr should probably be changed to
deliver 35% of the final rate over the first half hour and 65% of the final
rate over the second half hour.
For example a 2400 ml TPN is running at 100 ml/hr over 24 hours. To convert
to a cyclic TPN:
20 hr delivery: 2400/19=126 ml/hr x 18 hours which is a total of 2268 ml.
2400-2268=132 ml. One hour start and stop taper=66 ml/hr
16 hr delivery: 2400/15=160 ml/hr x 14 hours which is a total of 2240 ml.
2400-2240=160 ml. One hour start and stop rate=80 ml/hr.
12 hr delivery: 2400/11=218 ml/hr x 10 hours which is a total of 2180 ml.
2400-2180=220 ml. One hour start and stop rate =110 ml/hr. This rate may be
too fast as a start rate and a slower rate for the first 1/2 hour and last 1/2
hour of the taper may be required. Consider delivery of 35% of this rate over
the first half hour (77 ml/hr) and 65% (142 ml/hr) over the second half hour
which would equal a one hour start volume of 110 ml/hr. Taper the rate to 142
ml/hr for a half hour and then 77 ml/hr for a half hour when stopping the
cyclic TPN.
Fluid volume and infusion rates
Infusion rates must be ordered so the total fluid volume is given over 24
hours. If following the recommended initiation schedule, the first 24 hour bag
should be written for 2400 ml.
FLUID VOLUME/24 HOURS
INFUSION RATE
1000
ml
42 ml/hr
1200
ml
50 ml/hr
1800
ml
75 ml/hr
2000
ml
83 ml/hr
2400
ml
100 ml/hr
3000
ml
125 ml/hr
3600
ml
150 ml/hr
3-in-1 admixtures
Recommended only if the patient's additive profile is compatible with 3-in-1
mixing. Pharmacists will verify compatibility and will contact the physician if
there are problems. Patients who show a rapid elevation of triglycerides to
greater than>400 mg/dL upon fat emulsion infusion would NOT be
candidates for 24 hour 3-in-1 admixtures. |