Pharmacology, CH 8

fluids that have a diuretic effect on kidneys:

coffee, caffeinated sodas, and beer; they increase urination. These count as hydration, but are not best choices when intake and output are important to the patient's health

ratios

comparisons between two things

drug dose calculation:step 1:

conversion of numbers to the same unit of measurement

medication is absorbed differently in children and at a ___ rate

different; children's bodies cannot handle an adult dosage

fraction method:

dosage on hand desired dose ________________ = _______________ dosage unit dose given

drop factor =

drops per milliliter (gtt/mL; how many drips are in 1 mL)and is stated on the package of the IV tubing (the drop factor is built into electronic pumps because the tubing matches the pump)

If IV rate doesn't come out correctly, like it's taking 2 hours instead of 1,

report it to your supervisor of flow rate is not constant and correct. DO NOT change the flow rate because the change may cause the fluid or medication to be infused to quickly.

formula

rule prescribing how to calculate a dosage

electronic regulator pumps:

machines that deliver and monitor IV fluids at a set rate; these pumps alert health care professionals if a problem arises and allow them to perform other tasks; usually like 1000 mL/2 hours or 400 mL/8 hours

dimensional analysis

method based on the premise that any number can be multiplied by one without changing its value

IV tubing has either ___ or ___ chamber

microdrip or macrodrip chamber

physician may drug geriatric patient:

on an individual basis, after evaluating organ function and body weight; each medication might have a slightly different reaction, and must be assessed after each medication is begun or changes to doses implemented

nonparenteral

oral

complicated health of many elderly patients:

patients may be seeing a multitude of practitioners, each of whom treats a different health issue, as well as self medicating with vitamins and herbal medications

special calculations include:

pediatric and geriatric patients; their bodies are either immature (pediatric) or weakened by the aging process (geriatric)

reconstituting:

powdered medics occasionally must be converted to liquid form to be administered

IV tubing:

specific to the type of pump, run through an electronic regulator

proportion

statement saying those two ratios are equal

dimensional analysis steps:

step 1: write the units of the dose ordered step 2: write the units that are on the label and the unit that you plan to give the patient Mg (ordered) x ____ mL _______________________ = mL (desired) Mg for label (ordered)

drug quantities can be in:

tablets, capsules, milliliters, or another unit, and each label has its own equivalents

available dose

the dosage on hand

body surface area (define)

ratio of height to weight or total surface area of the human body; method most commonly used in children or administered chemotherapy to adults when dosage accuracy is critical

sample drug label should include 8 things:

1. brand name (trade) 2. generic name 3: drug strength 4 drug form, route of administration if other than oral, total amount of medication in the container, directions for reconstitution if necessary 5. manufacturer 6. National Drug Code (NDC) 7. expiration date 8. lot number

4 methods by which to calculate drug dosages for nonparenteral (oral) route of administration:

1. ratio and proportion method 2. formulation method 3. dimensional analysis 4. fractions

micro drip is:

60 gtt/mL

D = ? H = ? Q = ?

D = desired Dose H = on hand or available amount in ordered units Q = quantity in units given

IV formula:

Total mL ordered __________________________ = mL/hour (round 2 whole#) Total time ordered in hours

formula for the IV flow rate is:

Total volume (V) to be infused (mL) Drop factor (D) (gtt) Rate Flow (R)(gtt) ___________________________ x _______________ = _______ Total time in minutes mL min

simple formula for IV flow rate:

V ___ x D = R T

diluent

amount of fluid, used to reconstitute the formula adds to the powder's volume, so the final solution (powder and fluid) may be greater than the volume of the diluent

IV set must not:

be moved (gravity changes how fast the drops fall) or adjusted; doing so could change the drip rate

BSA:

body surface area, patient's weight or body surface to calculate for the correct dosage; convert patient's weight from pounds to kilos and then multiply that number by number of milligrams to determine the daily dosage

geriatric patients need medications:

calculated very carefully because of high risk for toxicity resulting from their aging body systems, particularly renal (kidneys) hepatic (liver) and circulatory systems

macrodrip is:

either 10 0r 15 gtt/mL, again as stated on the tubing practice

desired dose:

equals the dosage that has been ordered or ordered dose

fluid balance in pediatric and geriatric patients:

fluid balance is vital for life. Pediatric and geriatric patients can easily suffer from dehydration, overhydration, or electrolyte imbalances because of differences in their kidneys

conversion factor:

formula to change from one unit of measurement to another

the health care professional who starts the IV infusion establishes the rate by:

hanging the bag or bottle at a certain height and adjusting the number od drops per minute with the roller clamp

in children, total body water content is ____ in a child than an adult

higher

fluid output is determined by measuring:

in mL either urine or emesis (vomit) caught in a special container that includes the unit of measure

pediatric

infants and children

parenteral

intravenous or IV

Formulation method:

involves stacking units that are the same and multiplying by the unit requested.

dimensional analysis is best way:

to calculate an IV drip rate because this method uses ratios as conversion factors and reduces the possibility of errors

Manual IV sets

use gravity to infuse a solution at a set rate; this means you need to know the drop factor

after adding sterile water or saline solution;

use the conversion ratio on the drug label to calculate the dosage

Ratio and proportion method:

uses ratios, which are comparisons between two objects (numbers in this case) like 4 pieces of pepperoni pizza and 3 pieces of cheese pizza are 4:3::8:6 or 4/3 = 8/6. Medication order is for 400 mg. Available medication is 300 mg in 1mL. 300 mg/1mL = 400 mg/?mL

dimensional analysis:

uses the ordered amount of a drug to multiply with two equal quantities in different dimensions (units of measurement) to derive the answer

fraction method

uses two equivalent proportions to find the answer

drug dose calculation: step 2:

using the preferred method, write the problem on paper; check again to confirm that your calculations are correct

physician's order for fluid intake restrictions:

usually in milliliters mL

laws related to IV therapy:

vary from state to state

emesis

vomit

in pediatric population ____ is used to calculate dosages:

weight

infiltrated:

when there is leakage of IV fluid or medication into the surrounding tissue; you can cause damage by increasing the flow rate

you must know how IV dosages are calculated so

you can double-check other health-care workers calculations