Preparation of Solutions (cont.) Universal solvent – water Diluent Substance used to dilute Solvent Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Water is the most common solvent. Normal Saline is an example of a solution. 0.9 g of NaCl in each 100 mL NaCl is the solute. Water is the solvent or diluent.

Preparation of Solutions (cont.) Percent concentration Expression of the concentration Amount of solute per 100 mL solution Milliliters/100 mL for liquid solutes Grams/100 mL if solute is a solid or semisolid Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Most solutions are prepared by the manufacturer. Examples of solutions made by the manufacturer are: injections; eye drops; cough syrups. It may be necessary to prepare solutions from powders or dilute a more concentrated solution than the concentration ordered.

Preparation of Solutions (cont.) Example What is the amount of hydrocortisone powder in 300 mL of 2% hydrocortisone lotion? 2% hydrocortisone lotion contains 2 g of hydrocortisone powder per each 100 mL. Therefore, 300 mL will contain (2 g x 3) 6 g hydrocortisone powder. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

Preparation of Solutions (cont.) Example What is the amount of isopropyl alcohol in 100 mL of a 70% isopropyl alcohol solution? Percent strength = 70 so a 70% isopropyl alcohol solution has 70 mL isopropyl alcohol per each 100 mL solution. 100 mL has 70 mL isopropyl alcohol with enough water added to make a total of 100 mL. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

Preparation of Solutions (cont.) Rule 16-2 For solid or semisolid mixtures prepared with a dry medication, percent strength represents the number of grams of medication in 100 g of the mixture. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

Preparation of Solutions (cont.) Rule 16-2 (cont.) For solid or semisolid mixtures prepared with a liquid medication, percent strength represents the number of milliliters of medication in 100 g of the mixture. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

Preparation of Solutions (cont.) Determine the amount of hydrocortisone in 2% hydrocortisone ointment. Each 100 mL of ointment contains 2 g of hydrocortisone. 2 g hydrocortisone would be mixed with 98 g petroleum jelly. Example Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

Preparation of Solutions (cont.) When preparing percent solutions and solids measure the solute; add a sufficient quantity of solvent to bring the total to the desired volume; know qsad – a sufficient quantity to adjust the dimensions to…. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. qsad – Latin phrase To make a liquid solution, the diluents are added up to the desired volume.

Preparation of Solutions (cont.) A “recipe” for preparing 100 mL of 2% lidocaine solution: Example 2% Lidocaine Solution Lidocaine 2g Water qsad 100 mL Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. You must account for the volume of the lidocaine being added to the solution, so you add a sufficient quantity of water to equal 100 mL.

Preparation of Solutions (cont.) A “recipe” for preparing 100 g of 10% zinc oxide ointment from zinc oxide powder and petroleum jelly Example 10% Zinc Oxide Ointment Zinc Oxide 10g Petroleum jelly 90 g Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. When adding a solid to another solid (ointment base), subtract the number of grams of the solute from the total number of grams to determine how much base product you need. You do not use qsad when preparing solid mixtures.

Preparation of Solutions (cont.) Procedure Checklist 6-1: Calculating by the Proportion Method Write a conversion factor with the units needed in the numerator or before the colon; units converting from in the denominator or after the colon. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparation of Solutions (cont.) Procedure Checklist 6-1: (cont.) Write a factor with the unknown, “X,” in the numerator or before the colon . with the number to convert in the denominator or after the colon. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings X/B or X:B

Using Conversion Factors: Proportion Method (cont.) Procedure Checklist 6-1: (cont.) Set the two factors up as a proportion. Cancel units. Cross-multiply or multiply the means and extremes and solve for the unknown value. X/B = C/D or X:B = C:D Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings Remember rules for cancelling units. Cross-multiply for fractions Multiply means and extremes for ratios

Preparation of Solutions (cont.) Calculate the amount of NaCl needed for for 250 mL of 0.9% sodium chloride. 0.9 g NaCl in 100 mL solution Step A Convert No conversion is needed. Example Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparation of Solutions (cont.) Example 0.9 g NaCl in 100 mL solution Step B Calculate using the proportion method. 0.9 g /100 mL = X/250 mL 0.9 g x 250 = 100 x X 225 g/100 = 100X/100 2.25 g NaCl = X Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings First ratio is our known – 0.9 g / 100 mL solution Second ratio – X (the unknown)/250 mL Cancel units (mL). Cross multiply and solve the equation.

Preparation of Solutions (cont.) Step C Think!...Is It Reasonable? Since there is 0.9 g of NaCl in 100 mL, there should be more than 2 times that amount in 250 mL, so 2.25 g is a reasonable answer. Example Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparation of Solutions (cont.) Procedure Checklist 6-2: Calculating by Dimensional Analysis Write the unknown “X” on one side of the equation. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings X =

Preparation of Solutions (cont.) Procedure Checklist 6-2 (cont.) On the other side of the equation, write a conversion factor with the units of measure for the answer on top and the units you are converting from on the bottom. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparation of Solutions (cont.) Procedure Checklist 6-2 (cont.) Multiply the numerator of the conversion factor by the number that is being converted divided by 1. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparation of Solutions (cont.) Procedure Checklist 6-2 (cont.) Cancel units. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparation of Solutions (cont.) Procedure Checklist 6-2: Solve the equation. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparation of Solutions (cont.) Step C Think! … Is It Reasonable? Regardless of the method used, we find that 2.25 g of NaCl is needed to prepare 250 mL of a 0.9% solution. Example Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparation of Solutions (cont.) Write the recipe for 250 mL of 0.9% sodium chloride solution. Example 0.9% Sodium Chloride Solution NaCl 2.25 g Water qsad 250 mL Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Practice Write a recipe for preparing 50 g if a 10% zinc oxide ointment using zinc oxide powder and petrolatum jelly. ANSWER: 10% Zinc Oxide Ointment Zinc oxide powder 5g Petroleum jelly 45 g Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings Step A Convert – not necessary Step B Calculate – X = 10 g/100 g x 50g/1 X = 500g/100 X = 5 g Step C – 50 g is half of 100 g, so 5 g zinc oxide is reasonable.

Preparing a Dilution from a Concentrate When preparing a solution from two solutions of different concentration, know Solvent – less concentrated solution Solute – more concentrated solution To calculate, use Formula method Alligation Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparing a Dilution from a Concentrate (cont.) Procedure Checklist 16-1 Formula Method Identify information needed: V = volume of solution needed C = concentration of solution needed St = amount of solute Sv = amount of solvent Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparing a Dilution from a Concentrate (cont.) Procedure Checklist 16-1 (cont.) Insert values into formula: C x V = St Determine the amount of solvent by subtracting the solute from the total volume: V – St = Sv Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

Preparing a Dilution from a Concentrate (cont.) Ordered: 1 oz of ¼ strength hydrogen peroxide in normal saline for wound care TID for 2 days. Write the recipe. Step A = Convert ounces to mL. 1 oz TID x 2 day = 6 oz 1oz/30 mL = 6 oz/ X 180 mL = X Example Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings Use method of choice. Cancel units (oz). Solve.

Preparing a Dilution from a Concentrate (cont.) Step B Calculate. V = 180 mL, C = ¼ C x V = St ¼ x 180 mL = 45 mL of the solute (hydrogen peroxide) V – St = Sv 180 mL – 45 mL = 135 mL of the solvent (normal saline) Example Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feeding Set up problem – insert values.

Preparing a Dilution from a Concentrate (cont.) The recipe is: Step C Since 45 is one fourth of the total volume of solution (180 mL) and 135 + 45 = 180 mL, this answer is reasonable. Example ¼ strength Hydrogen Peroxide – 180 mL H2O2 45 mL NS 135 mL Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings

½ hydrogen peroxide – 720 mL Practice Clean leg wound with 2 oz of ½ strength hydrogen peroxide in normal saline q6 h x 3 days. Write the recipe for total supply needed. ½ hydrogen peroxide – 720 mL H2O2 360 mL NS 360 mL ANSWER: Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Learning Outcome: 16.2 Calculate the amount of solute and solvent needed to prepare a desired strength for: Topical solutions/irrigants Enteral feedings Step A Convert mL to oz 2 oz x 4 times/day x 3 days = 24 oz. 1 oz: 30 mL = 24 oz : X [cancel units (oz)] 720 mL = X Step B Calculate. C x V = St ½ x720 mL = 360 mL hydrogen peroxide (solute) V - St = Sv 720 mL – 360 mL = 360 mL normal saline (solvent) Step C 360 mL is half total volume, so it is reasonable.

Patient Education Mixing infant formulas Know that most formulas have 20 calories / ounce. Wash hands and top of formula can before starting. Let cold water run for 2 minutes. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Some babies may need fewer calories. Use clean measuring devices. Reduce the amount of lead (do not use well water – may contain bacteria).

Patient Education When using liquid formulas Check that label reads “concentrate”; shake before opening; follow recipe from AP; pour formula concentrate into another container; measure desired amount of water; add to concentrate and mix well. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. A – Label should not read “ready-to-use.” E – Use a clear liquid measuring cup.

Patient Education When using powdered formulas follow instruction of AP; measure desired amount of water; check liquid level at eye level; add level measures of formula powder; use scoop provided; mix or shake well. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. B – Use a liquid measuring cup. C – Set cup on level surface to measure. D – Do not pack powder into measuring device. E – You may use measuring devices indented for dry ingredients. F – Be sure lumps are gone.

Patient Education When storing formula refrigerate in a covered container; throw away unused prepared formula after 48 hours; throw away unused formula powder one month after opening the can. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid.

Patient Education When feeding with formula shake formula well; warm bottle; do not use microwave; shake bottle after warming; test temperature of formula; discard formula left in bottle after feeding. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. B – Warm bottle under warm tap water, or set bottle in a pan of warm water. C – Microwave heats unevenly and can cause hot spots that might burn the baby’s mouth. E – Test before feeding.

Label all patient tubing. ERROR ALERT! Label all patient tubing. Learning Outcome: 16.1 Write a recipe for preparing a percent solution or solid. Eliminates errors that might occur when tubing is not marked Reduces the chance of tube feedings being through an IV catheter