Starting unit x ( Desired unit / Starting unit )
Starting Unit : What you are giving to the pt / What is ordered for the patient
Desired Unit : What we are solving for ( at the end what do we want to have )
Starting Unit : What is available for us to give to the patient
Step 1 : Set Your Goal : Know what you are solving for
You need to administer 50 mg , and you know your stock is 100 mg in 2 mL .
Step 2 : Set Up Your Equation
Here ’ s how you ’ d set up your equation using dimensional analysis :
50mg × ( 2mL / 100 mg )
Step 3 : Do the Math
Cancel out like units and carry out the multiplication and division :
50 × ( 2mL / 100 ) = 1mL
The units cancel out just right , leaving you with mL , which is what you want for administering the liquid medication .
Dimensional Analysis Tips
Pro Tip 1 : multiply straight across and then divide the answer you got in the numerator by the answer you got in the denominator .
Pro Tip 2 : check your “ design ”. Like units should always be diagonal to each other ( aka one in the numerator and one in the denominator ) and NEVER horizontal to each ( across from each other ) If they are horizontal you can ’ t cancel them out ( Smith , 2020 ).
Pro Tip 3 : when you are done canceling out like you units the only units left should be your desired units ( what you are solving for ). If you have extra units , reread the problem and check your “ design ”.
Pro Tip 4 : Keep units clear by always writing out your units . This helps avoid confusion .
Wrapping It Up
Both methods are invaluable , but they serve slightly different needs . The formula method is great for straightforward , quick calculations , while dimensional analysis offers a rigorous approach suitable for complex calculations involving multiple unit conversions . As a nursing student and future nurse , mastering both techniques will equip you with the tools to ensure safe medication administration and uphold the highest standards of patient care ( Murphy , Ozimek , Wendel , & Murphy , n . d .).
Remember , nursing is a field where lifelong learning and accuracy go hand in hand . Embrace every learning opportunity , engage actively in your education , and always strive for precision . Mistakes are learning opportunities — each one teaches you something valuable .
Thank you for joining me in this detailed exploration of medication dosage calculations . Keep practicing , stay curious , and continue to advocate for your patients through accurate and safe medication administration . You ’ re doing more than just passing exams ; you ’ re learning to save lives . You got this !
Keep pushing forward , keep learning , and most importantly , keep caring . Together , we ’ re making a difference — one calculation at a time .
Stay curious , stay motivated , and let ’ s keep those calculations accurate !
References
Murphy , G ., Ozimek , D ., Wendel , A ., & Murphy , J . ( n . d .). Teaching dosage calculations : Strategies for narrowing the theory-practice gap . Pennsylvania College of Health Sciences , Drexel University . National Council of State Boards of Nursing . https :// www . ncsbn . org / public-files / Final _ TeachingDosageWebinar . pdf
Smith , L . The trap guide to nursing dosage calculation with Latoya , RN . Latoya Smith . Tulsa : Because I ’ m A Nurse Publishing ; 2020 .
Toney-Butler TJ , Nicolas S , Wilcox L . ( 2023 ). Dose Calculation Desired Over Have Formula Method . In : StatPearls [ Internet ]. Treasure Island ( FL ): StatPearls Publishing . https :// pubmed . ncbi . nlm . nih . gov / 29630214 /
Bio
Latoya Smith , RN , affectionately known as Nurse Toya , is a seasoned registered nurse , a nurse innovator , and a passionate educator in the nursing profession . She is particularly focused on improving medication dosage calculations among nursing students , an area she believes is crucial for patient safety and effective treatment . Her interactive workshops and seminars have inspired a new generation of nurses to approach their education and practice with confidence and precision . Nurse Toya is committed to transforming nursing education by integrating innovative learning methods and supportive technologies . She is the founder of the Oklahoma Nurse Innovators Network , a chapter of the Oklahoma Nurses Association .
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