1. Intravenous Solutions, Equipment, and Calculations
Chapter 15
Intravenous Solutions, Equipment, and Calculations
MOVING INTO ADVANCED CALCULATIONS: ADVISE CLASS TO LISTEN CAREFULLY TO LECTURE TODAY
IV or intravenous refers to the administration of fluids, nutrients, and medication through a vein.
IV therapy is an important and challenging nursing responsibility.
IV solutions are ordered by the MD, but administered and monitored by the nurse.
Using 6 medication rights
Supplied in plastic bags or glass bottles with volumes of 50 mL to 1,ooo mL ( and some more ie peritoneal dialysis or TPN)
Lets begin by analyzing IV solutions

2. GOAL OF IV THERAPY:
To maintain or regain fluid and electrolyte balance!

3. IV Solution Components
Abbreviation
Solution Component D
Dextrose W
Water S
Saline NS
Normal saline (0.9% NaCl)
NaCl
Sodium chloride RL
Ringer’s lactate LR
Lactated Ringer’s
Also, selected electrolytes are found in IV solns
dextrose and sodium chloride are the 2 most common solute components.
Memorize this chart!!
Besides SOLUTION COMPONENTS, we need to look at SOLUTION STRENGTH. The abbreviation letters indicate solution components, the NUMBER indicate soln strength or concentration of the components
Write on board: D5W aka dextrose 5% in water .
What is the solvent? (water)
Recall from chapter 8 in reading drug labels that parenteral solutions expressed in a percent indicate X g per 100 mL
Looking at the IV bag notice that each 100 mL contains 5g dextrose
Option to look at all examples

4. Saline Solutions Normal Saline
term for 0.9% Sodium Chloride (NaCl) ; has the same concentration of NaCl present in the blood. “physiologic saline”
0.45% NaCl
0.225% NaCl
Common solutions
0.45% = 450 mg NaCl per 100 mL
0.225% = 225 mg NaCl per 100 mL

5. Comparison of IV Solutions
Types of IV solution concentrations by osmolarity
Hypotonic
Isotonic
Hypertonic
IV fluids are concentrated and have classifications based on those concentrations:
OSMOLARITY: concentration/property of active particles
Chart on page 476

6. Normal Serum Osmolarity
Hypotonic
Less than 250 milliosmole (mOsm) per L
Solvent exceeds the solute
Used to dilute excess serum electrolytes
E.g., 0.45 % saline (154 mOsm/L)
So when fluid needs to be shifted into the cell Such as hyperglycemia
USE IV LABELS PAGE 476

7. Normal Serum Osmolarity
Isotonic
250 to 375 mOsm per L
Used to expand volume and maintain normal tonicity
Solvent and solutes are balanced
E.g., 0.9 % saline (308 mOsm/L), lactated Ringer’s (273 mOsm/L), 5 % dextrose in water (252 mOsm/L)
Examples: to the OR, maintenance fluid aka PHYSIOLOGIC SALINE
Page 475 Label

8. Normal Serum Osmolarity
Hypertonic
Greater than 375 mOsm per L
Used to correct electrolyte imbalances
Solutes exceed solvent
E.g., 5 % dextrose and 0.9% NaCl (560 mOsm/L); 5 % dextrose and lactated Ringer’s (525 mOsm/L)
Examples: excessive vomiting, diarrhea, hemorrhaging…hypovolemia
KNOW CHART PG 476 REVIEW SET 32 PT 477 (1-5)
Page 475 label

9. Calculating IV Solution and Strength
Solution strengths are expressed as a percent to indicate number of grams of solute per 100 mL solution
Calculating the amount of solutes: dextrose, saline
D5W 1000 mL IV q 8 h (E)
D 5 1/4 NS 500 mL IV q 6 h (A)
Page 479 DO ON BOARD
It is not necessary to perform this calculation every time you give IV solns, but the concept is important because it helps you understand that IV solns provide much more than fluid…they have other components

10. Practice
Review Set 33
Page 481
Questions 2-5

11. IV Sites Peripheral line Central line
Rate of infusion should not exceed 200 mL in one hour
Accommodates a maximum glucose concentration of 12%
Central line
Accommodates larger concentrations and volumes of fluid
Accommodates up to 35% glucose
Utilized for long term therapy
Where do we place peripheral lines? Central lines? Infants/scalp veins
Transparent ivf vs. blood, albumin with increased visicosity

12. Monitoring IVs Nursing responsibility
Check every 30 minutes to one hour:
Fluid volume remaining
Infusion rate
Signs of complications
Phlebitis
Infiltration
Infection

13. Electronically Regulated IVs
Most often, IV solutions are regulated electronically by an infusion device—an IV pump:
Infusion pump—maintain flow by displacing fluid at the prescribed rate
Syringe pump—infuses fluids or medications directly from a syringe
Patient-controlled analgesia (PCA) pump
Page 488
The nurses program these pumps and need to monitor accordingly. We do not typically use gravity as a method due to safety concerns

14. IV Flow Rate Ordered by physician Measured and prescribed in:
mL per hour
gtts per minute
Nurse’s responsibility to understand the order, regulate, monitor, and maintain
What are we monitoring? These fluids are going directly into the circulatory system.
Site, not getting too much or too little of ivf or medication, Accurately set and maintain flow rate, Record fluids and flow rates on the MAR hourly,
Note when bag and tubing need to be changed and when ivf is complete!

15. IV Flow Rate: mL per Hour
Regulate IV volume by electronic infusion pump or controller calibrated in mL per hour
Calculate using formula method:
Calculate using ratio-proportion:
Write on board
Can calculate using the Formula Method or the Ratio/Proportion Method

16. Calculating IV Flow Rate
mL per hour example:
Order: D5W 250 mL IV during next 2 h by infusion pump
ASK: what are total ml’s ordered? ASK: over what time period?
we can estimate as step 2 in our 3 step approach
Ask: what is maximum rate per hour to infuse??
Book states we don’t want to infuse more than 200 mL per hour in a peripheral vein mL per hour is reasonable

17. Calculating IV Flow Rate
Think
Pump set by rate of mL per hour
If 250 mL is to be infused in two hours, how much will be infused in one hour?
125 mL will be infused in one hour
Set pump at 125 mL per hour
Animations x 2
Using formula method(next slide)

18. Calculating IV Flow Rate
Use formula method
Set pump at 125 mL per hour

19. Calculating IV Flow Rate
Can also solve using ratio-proportion
Can give off the top examples on board for practice
1000 mL over 10 hours = 100 mL/hour
500 mL over 8 hours = 62.5 mL/hour

20. Calculating IV Flow Rate
Example of mL per hour with infusion rate of less than one hour: (minutes)
Use ratio-proportion
Round mL/h to a whole number or tenths, depending on equipment
For less than 1 hour: 2nd formula to know
Write formula on the board.

21. Calculating IV Flow Rate
Example: mL per hour with infusion rate of less than one hour:
Order: Ampicillin 500 mg IV in 50 mL
D5 NS in 30 minutes by controller

22. Calculating IV Flow Rate
Think
Controller set by rate of mL per hour
If 50 mL is to be infused in 30 minutes:
100 mL will be infused in 60 minutes
Set rate of controller at 100 mL per hour to infuse 50 mL in 30 minutes

23. Calculating IV Flow Rate
Use ratio-proportion

24. PRACTICE
Review set 34 Page 492 Questions 1-5

25. IV Flow Rate: Drops per Minute
Formula for IV flow rate for manually regulated IVs ordered in mL per hour or for minutes
Volume to be infused (mL)
Calibration of tubing (drop factor) gtt/mL
WRITE ON BOARD WHAT IF THERE IS NO PUMP??
This can be used as a backup incase of pump failure. The nurse needs to calculate the ordered IV rate based on a certain number of drops per minute( gtt/min). This represents the ordered milliliters per hour. The nurse regulates this by using
Need a watch w/ a second hand holding it up to the drop chamber counting whole drops for 1 minute. THE FLOW RATE DEPENDS OF THE IV TUBING CALIBRATION, CALLED THE DROP FACTOR. (which is on package of tubing)
Time required (min)
Rate of flow in gtt/min

26. RULE Drop Factor = gtt/mL
The drop factor is the number of drops per milliliter (gtt/mL) that a particular IV tubing set will deliver.
Determined by the size of the tubing or needle releasing the drops into the drip chamber.
HOW do we know the drop factor? Stated on the IV tubing package label
Macro drop factors 10,15,20 gtt.ml vs Micro drop factor 60 gtt/ml
Hospitals usually stock one macrodrop tubing for rountine adult IV admin and the microdrop tubing for more exact measurements
Turn to page

27. Drip Chambers
MACRO
MICRO

29. Inserting IV bag and using clamp
The number of drops falling per minute into IV drip chamber is counted and regulated by opening and closing the roller clamp

30. IV Flow Rate: Drops per Minute
Carry calculations to one decimal
Round drops per minute to nearest whole number
Can watch-count only whole drops

31. Calculating Drops per Minute
Example:
Order: D5W IV at 125 mL per hour
Infusion set calibrated for drop factor of 10 drops per mL
Calculate IV flow rate in drops per minute
Me: write out formula on board V/T x C=
Me: turn to page 496 for examples MY COPIED PAGE

32. Formula for manually regulated IV’s in gtt/min

33. Calculating Drops per Minute
Notice that mL cancel out
Leaving gtt per minute
Use watch to count drops and adjust roller clamp to deliver 21 drops per minute 6
Example 2, 3 page ON BOARD!!

34. Calculating Drops per Minute: Microdrip Drop Factor
When IV drop factor is 60 drops per mL (microdrip sets):
Flow rate in drops per minute is same as volume ordered in mL per hour
Example 4 shown on next slide: ON BOARD write order: D5 NS IV at 50 mL per hour

35. Calculating Drops per Minute: Microdrip Drop Factor
Example:
Order: D5W NS IV at 50 mL per hour
Drop factor: 60 drops per mL
Notice order is same as flow rate of 50 drops per minute when drop factor is 60 drops per mL
Used for many pediatric/NICU set ups

36. PRACTICE Review Set 36 Page 497 Questions 2-8 Review set 36 1-8
GO TO SLIDE 45

37. Drop Factor Constants Drop Factor Drop Factor Constant 10 drops per mL
GO TO SLIDE 59
This is a shortcut method to calculate IV flowrate
The drop factor constant is equal to minutes

38. Drop Factor Constants
Administer 125 mL per hour IV with 20 drops per mL infusion set 3

39. IV Flow Rate Shortcut Method
Shortcut to calculate IV flow rate:
Write on board from page 499 example 1 and 2

40. Adjusting IV Flow Rate
Nurse may not arbitrarily speed up or slow down flow rate to catch up IV
Check institutional policy regarding correction of off-schedule IV rates and percentage of variation allowed
Should not exceed 25 percent

41. PRACTICE Review Set 37 Page 500 Questions 1-10
SKIP TO SLIDE 48 AFTER DONE WITH REVIEW

42. Adjusting IV Flow Rate If adjustment permitted:
Use formula to recalculate mL per hour and gtt per minute for time remaining and percentage of variation
NO…slides 41-46
Not up to nurse to arbitrarily speed up or slow sown the IV flow rate.
Can have unintended consequences.
IV’s must be checked frquently 15 min to hourly
Safe rule of thumb is that the flow rate epr minute may be adjusted by up to 25% mor or less thatn the original prescribed rate. BEST to notify MD

43. Adjusting IV Flow Rate no

44. Adjusting IV Flow Rate
Percent variation will be positive (+) if administration is too slow
Rate must be increased
Percent variation will be negative () if administration is too fast
Rate must be decreased no

45. Calculating IV Flow Rate Adjustment
Example:
Order: 500 mL LR to run over 10 h at 50 mL per hour
Drop factor is 60 drops per mL
IV is correctly infusing at 50 drops per minute
After 2 hours, 300 mL remaining
Almost half of total volume infused in one-quarter the time no

46. Calculating IV Flow Rate Adjustment
IV infusion ahead of schedule
Compute new rate of 300 mL to complete IV fluid order in remaining 7 hours
Patient requires close assessment for fluid overload no

47. Calculating IV Flow Rate Adjustment
Variation of negative percent indicates rate will be decreased no

48. Calculating Intermittent IV Infusion Rates for IV PB
Example:
Order: Cefazolin 0.5 g in 100 mL D5W over 30 min
Drop factor is 20 gtt per mL
Write formula in board V/T x C =
Explain that sometimes a pt is only on an IV for medication OR IVF at scheduled times.
Page 512

49. Calculating Intermittent IV Infusion Rates for IV PB
Calculate flow rate in gtt per minute 2 3

50. Calculating Intermittent IV Infusion Rates for IV PB
Calculate infusion rate for same order if infusion pump used
Think
If 100 mL will be administered in 30 minutes, then 200 mL will be administered in 60 minutes
REMEMBER: you will need to program the device in mL/h

51. Calculating Intermittent IV Infusion Rates for IV PB
Calculate using ratio-proportion
Practice problems REVIEW SET
TO SLIDE 60

52. Calculating Intermittent IV Push Rate
Caution:
IV drugs are rapidly distributed in the bloodstream.
Never infuse IV push drugs more rapidly than recommended
Some drugs require further dilution after reconstitution
Read package inserts and drug resources for administration guidelines
NO from slide 51-58

53. Calculating Intermittent IV Push Rate
Example:
Order: Ativan 3 mg IV Push 20 min preoperatively
Available: Ativan 4 mg per mL with drug literature guidelines of “IV infusion not to exceed 2 mg/min”
How much Ativan should be prepared?
Me: go to next slide

54. Calculating Intermittent IV Push Rate
Convert
No conversion necessary
Think
Estimate giving less than 1 mL
Calculate
Ask class : hoiw many mL will we give?

55. Calculating Intermittent IV Push Rate
Calculate

56. Calculating Intermittent IV Push Rate
What is a safe infusion time?
Use ratio-proportion
2 mg/min is recommended infusion rate

57. Calculating Intermittent IV Push Rate
How much should be infused every 15 seconds?
Convert minutes to seconds
One minute equals 60 seconds

58. Calculating Intermittent IV Push Rate
How much should be infused every 15 seconds?
Use ratio-proportion
What size syringe will you use?

59. Calculating Intermittent IV Push Rate
Use 1 mL syringe to draw up 0.75 mL of Ativan 4 mg per mL
Infuse via IV push at rate of 0.13 mL every 15 seconds for total of 1 minutes

60. PRACTICE
Review Set 40 Questions 1-5

61. Calculating Flow Rates Using a Dial-Flow Controller
Usually requires a few readjustments until desired flow rate is achieved
Widely used to reduce inconvenience and time
Same principle as roller clamp but with numbers
Cost-saving alternative to electronic infusion devices
Not more accurate than a general IV set alone no

62. Calculating IV Infusion Time and Volume
IV solutions prescribed number of mL/hour
Nurse may need to calculate total infusion time
Use fractions for hours that are not whole numbers
Write formula on board: Total volume ÷ mL/h = Total hours
Page 518 can also write ratio/ proportion

63. Example for calculating Time
LR 1,000 mL IV to infuse at 125 mL per hour. How long will this IV last?
Page 518
Total volume ÷ mL/h = Total hours
1,000 ÷ 125 mL/h = 8 h (formula method)
Can give off the top examples: 500 mL to infuse at 50 mL per hour

64. Calculating Total IV Infusion Time
Example:
D5W 1,000 mL to infuse at 60 mL per hour
If infusion begins at 0600, what time will infusion be complete?
Write on board

65. Calculating Total IV Infusion Time
Use ratio-proportion
Use formula method:
total volume = total hours
mL/ h
Write on board:

66. Calculating Total IV Infusion Time
Use ratio-proportion
0.6 = 6/10 =
2/3 x 60/1 = 40 min
Multiply .66 x 60 min = 39.6

67. Calculating Total IV Infusion Time
IV will be complete at:
Time started
Time of completion
Time infusion will run

68. Calculate IV Fluid Volume
To calculate IV volume:
Flow rate (mL/h) and time (h) are known
Calculate using formula:
Calculate using ratio-proportion:

69. Calculate IV Fluid Volume
Example:
IV is infusing per infusion pump at 100 mL per hour
How much will infuse during the next eight hours?
FORMULA: Total hours x mL/h = total mL

70. Calculate IV Fluid Volume
Apply formula
Use ratio-proportion

71. Practice
Review Set 41 Page 520 Questions 1-6

74. Calculating IV Fluid Volume
Example:
At 7 am, IV of D5W is infusing at 25 gtt per minute
Drop factor is 15 gtt per mL
How much will the patient receive in eight hours?

75. Calculating IV Fluid Volume
Convert hours to minutes

76. Calculating IV Fluid Volume
Apply formula

77. Calculating IV Fluid Volume
Apply formula

78. Calculating IV Fluid Volume
To calculate IV volume:
Flow rate (drops per minute), drop factor, and time are known
V is unknown

80. Calculating Total IV Infusion Time
Use ratio-proportion
0.6 = 6/10 =
2/3 x 60/1 = 40 min
Multiply .66 x 60 min = 39.6