Medical Dosage Calculations A Dimensional Analysis Approach Eleventh Edition Chapter 10 Flow Rates and Durations of Enteral and Intravenous Infusions

Learning Objectives 10.1 Describe the basic concepts and standard equipment used in administering enteral and intravenous (IV) infusions. 10.2 Quickly convert flow rates between gtt/min and mL/h. 10.3 Calculate the flow rates of enteral and IV infusions. 10.4 Calculate the durations of enteral and IV infusions. 10.5 Determine fluid replacement volumes. Slide 2 is list of textbook LO numbers and statements

Introduction to Intravenous and Enteral Solutions Fluids can be given to a patient slowly over a period of time: through a vein (intravenous). or through a tube inserted into the alimentary tract (enteral).

Enteral Feedings Tube feedings provide nutrients and other fluids by way of a tube inserted directly into the gastrointestinal system. May be given continuously or intermittently 24 hour periods at most Orders always indicate a flow rate. FLOW RATE = Volume of fluid to be infused over a period of time. 𝐹𝑙𝑜𝑤 𝑟𝑎𝑡𝑒= 𝑉𝑜𝑙𝑢𝑚𝑒 𝑇𝑖𝑚𝑒

Figure 10.1 A patient with a nasogastric tube.

Figure 10.2 A percutaneous endoscopic jejunostomy (PEJ) tube.

Figure 10.3 Enteral feeding via pump. (Photographer; Elena Dorfman)

Intravenous Infusions and Solutions (1 of 2) IV means "through the vein" Replacement fluids and maintenance fluids Infusions can be continuous or intermittent. Intermittent peripheral infusion devices maintain venous access.

Intravenous Infusions and Solutions (2 of 2) Intravenous Solutions Saline solution is commonly used. Intravenous fluids generally contain dextrose, sodium chloride, or electrolytes. D5W, D5/W, or 5% D/W is a 5% dextrose solution. 5 𝑔 𝐷𝑒𝑥𝑡𝑜𝑠𝑒 100 𝑚𝑙 𝑠𝑜𝑙𝑢𝑡𝑖𝑜𝑛 NS – Normal Saline – 0.9% NaCl 1 2 NS – Half Normal Saline – 0.45% NaCl 1 4 NS – Quarter Normal Saline – 0.225% NaCl

Infusion Flow Rates Drops per Minute = 𝑔𝑡𝑡 𝑚𝑖𝑛 Milliliters per Hour = 𝑚𝐿 ℎ

Figure 10. 4 Examples of IV bags and labels. (10-04a AI Dodge/AI Dodge Figure 10.4 Examples of IV bags and labels. (10-04a AI Dodge/AI Dodge. 10-04b Courtesy of Baxter Healthcare Corporation. All rights reserved. 10-04c AI Dodge/AI Dodge. 10-04d Reproduced with permission of Abbott Laboratories) (1 of 4)

Figure 10. 4 Examples of IV bags and labels. (10-04a AI Dodge/AI Dodge Figure 10.4 Examples of IV bags and labels. (10-04a AI Dodge/AI Dodge. 10-04b Courtesy of Baxter Healthcare Corporation. All rights reserved. 10-04c AI Dodge/AI Dodge. 10-04d Reproduced with permission of Abbott Laboratories) (2 of 4)

Figure 10. 4 Examples of IV bags and labels. (10-04a AI Dodge/AI Dodge Figure 10.4 Examples of IV bags and labels. (10-04a AI Dodge/AI Dodge. 10-04b Courtesy of Baxter Healthcare Corporation. All rights reserved. 10-04c AI Dodge/AI Dodge. 10-04d Reproduced with permission of Abbott Laboratories) (3 of 4)

Figure 10. 4 Examples of IV bags and labels. (10-04a AI Dodge/AI Dodge Figure 10.4 Examples of IV bags and labels. (10-04a AI Dodge/AI Dodge. 10-04b Courtesy of Baxter Healthcare Corporation. All rights reserved. 10-04c AI Dodge/AI Dodge. 10-04d Reproduced with permission of Abbott Laboratories) (4 of 4)

Figure 10. 5 Examples of intravenous fluids Figure 10.5 Examples of intravenous fluids. (Reproduced with permission of Abbott Laboratories.) (1 of 4)

Figure 10. 5 Examples of intravenous fluids Figure 10.5 Examples of intravenous fluids. (Reproduced with permission of Abbott Laboratories.) (2 of 4)

Figure 10. 5 Examples of intravenous fluids Figure 10.5 Examples of intravenous fluids. (Reproduced with permission of Abbott Laboratories.) (3 of 4)

Figure 10. 5 Examples of intravenous fluids Figure 10.5 Examples of intravenous fluids. (Reproduced with permission of Abbott Laboratories.) (4 of 4)

Gravity Systems and Pumps (1 of 2) Flow Rate Regulation Rate of flow is regulated by an electronic device or gravity. IV tubing drop delivery is not standard. Manufacturers specify the number of drops that equal 1mL for their particular tubing. Drop factor Essential to calculating flow rates

Figure 10.6 Primary intravenous line (gravity flow).

Figure 10.7 Tubing with drip chamber. (Photodisc/Getty Images)

Figure 10.8 Samples of IV tubing containers with drop factors of 10 and 60. (10-8a Courtesy of Baxter Healthcare Corporation. All rights reserved. 10-8b AI Dodge/AI Dodge)

Gravity Systems and Pumps (2 of 2) Table 10.1 Common Drop Factors 10 gtt = 1 mL macrodrops 15 gtt 20 gtt 60 mcgtt microdrops

Figure 10.9 Volumetric infusion pump.

Figure 10.10 Patient-Controlled Analgesia (PCA) (a) pump (b) control button.

Finding the Flow Rate on a Pump Example 10.1 Order: NS 1,000 mL IV stat infuse in 8 hr. Find the flow rate (pump setting) in mL/h.

Finding the Flow Rate on a Pump Example 10.2 (1 of 2) 1,000 mL of NS must infuse via IV over 8 hours. The drop factor is 20 gtt/mL. Find the flow rate in gtt/min.

Finding the Flow Rate on a Pump Example 10.2 (2 of 2)

Finding the Flow Rate on a Pump Example 10.3 (1 of 3) The order is 775 mL of 5% D/W b.i.d infuse in 6 hours. Initially, the flow rate was set at 26 drops per minute. You assess the infusion 3 hours later, and the patient has received 500 mL. The drop factor is 10 gtt/mL. Recalculate the flow rate so that the infusion finishes on time.

Finding the Flow Rate on a Pump Example 10.3 (2 of 3) The remaining IV fluid (275 mL) must infuse in the remaining time (3 h).

Finding the Flow Rate on a Pump Example 10.3 (3 of 3)

Calculating the Duration of Flow for IV and Enteral Solutions Example 10.4 (1 of 2) An infusion of 5% D/W begins with 300 mL in the IV bag. The pump is set at 60 mL/h. How many hours will it take for the infusion to complete? 60 𝑚𝐿 ℎ = 300 𝑚𝐿 𝑡𝑖𝑚𝑒 t𝑖𝑚𝑒=𝑣𝑜𝑙𝑢𝑚𝑒 ∗𝑓𝑙𝑜𝑤 𝑟𝑎𝑡𝑒

Calculating the Duration of Flow for IV and Enteral Solutions Example 10.4 (2 of 2) Convert the volume in the bag (300 mL) to hours using the flow rate as the unit fraction.

Calculating the Duration of Flow for IV and Enteral Solutions Example 10.5 If the drip rate is 30 gtt/min, how many mL will infuse in 6 hours? The drop factor is 10 gtt/mL. Convert the time (6 h) to volume infused (mL) using the flow rate as a unit fraction.

Chapter Summary (1 of 2) Fluids can be given to a patient slowly over a period of time through a vein (intravenous) or through a tube inserted into the alimentary tract (enteral). Enteral and IV fluids can be administered continuously or intermittently. In IV solutions, letters indicate solution compounds, whereas numbers indicate solution concentration (e.g., D5W).

Chapter Summary (2 of 2) An intravenous infusion can flow solely by the force of gravity or by an electronic infusion pump. Flow rates are usually given as either mL/h or gtt/min. The drop factor of the IV administration set must be known in order to calculate gravity system flow rates. Microdrops/minute are equivalent to milliliters/hour.