Experience in Posology

Student nurses need more than maths to improve their drug calculating skills

Nurses need to be able to calculate accurate drug calculations in order to safely administer drugs to their patients (NMC, 2002). Studies have shown however that nurses do not always have the necessary skills to calculate accurate drug dosages and are potentially administering incorrect dosages of drugs to their patients (Hutton, M. 1998. Nursing Mathematics: the importance of application. Nursing Standard 13(11), 35-38; Kapborg, I. 1994. Calculation and administration of drug dosage by Swedish nurses, Student Nurses and Physicians. International Journal for Quality in Health Care 6(4), 389-395; O'Shea, E. 1999. Factors contributing to medication errors: a literature review. Journal of Advanced Nursing 8, 496-504; Wilson, A. 2003. Nurses maths: researching a practical approach. Nursing Standard 17(47), 33-36). The literature indicates that in order to improve drug calculations strategies need to focus on both the mathematical skills and conceptual skills of student nurses so they can interpret clinical data into drug calculations to be solved. A study was undertaken to investigate the effectiveness of implementing several strategies which focussed on developing the mathematical and conceptual skills of student nurses to improve their drug calculation skills. The study found that implementing a range of strategies which addressed these two developmental areas significantly improved the drug calculation skills of nurses. The study also indicates that a range of strategies has the potential ensuring that the skills taught are retained by the student nurses. Although the strategies significantly improved the drug calculation skills of student nurses, the fact that only 2 students were able to achieve 100% in their drug calculation test indicates a need for further research into this area.

Characteristics of medication errors made by students during the administration phase: a descriptive study

Faculty concentrate on teaching nursing students about safe medication administration practices and on challenging them to develop skills for calculating drug dose and intravenous flow rate problems. In spite of these efforts, students make medication errors and little is known about the attributes of these errors. Therefore, this descriptive, retrospective, secondary analysis study examined the characteristics of medication errors made by nursing students during the administration phase of the medication use process as reported to the MEDMARX, a database operated by the United States Pharmacopeia through the Patient Safety Program. Fewer than 3% of 1,305 student-made medication errors occurring in the administration process resulted in patient harm. Most were omission errors, followed by errors of giving the wrong dose (amount) of a drug. The most prevalent cause of the errors was students' performance deficits, whereas inexperience and distractions were leading contributing factors. The antimicrobial therapeutic class of drugs and the 10 subcategories within this class were the most commonly reported medications involved. Insulin was the highest-frequency single medication reported. Overall, this study shows that students' administration errors may be more frequent than suspected. Faculty might consider curriculum revisions that incorporate medication use safety throughout each course in nursing major courses.

Medication Errors: More Basic Than a System Issue

The Institute of Medicine's 2000 report drew attention to both U.S. health care agencies and the medication errors that occur within them. However, this attention focused on a more basic and fundamental issue within the medication error concern: nurses' mathematical skills and competence. This article describes a nationwide study assessing processes to validate mathematical skills for medication administration. Practices within educational and acute care institutions are explored, and recommendations for future action are noted with a call for 100% accuracy on all mathematical examinations for medication administration.

The 4 Cs: a model for teaching dosage calculation

Performing dosage calculation can be viewed as the ability to perform the 4 Cs: compute, convert, conceptualize, and critically evaluate. Ability to perform the 4 Cs is dependent on a variety of student and program factors. A model for teaching dosage calculation, grounded in research on mathematical success, is presented. Strategies for teaching dosage calculation based on this model are discussed.

Refinements in the dimensional analysis method of dose calculation problem-solving

Although the dimensional analysis method for solving dose calculation problems is gaining acceptance with nurse educators, many inconsistencies in teaching methodologies remain that can be confusing to both students and practicing nurses. The author presents refinements to the dimensional analysis method which can improve speed and accuracy in dose calculations and will be universally applicable to all types of clinical dosage problems.

Numeracy needs of the beginning registered nurse

The literature indicates: Nursing students demonstrate serious numeracy skills deficits. Consensus that such skills are necessary, particularly for medication administration. Diagnostic testing and remediation are desirable, or basic mathematics is pre-requisite for entry into nursing courses. Calculation skills mastered at one point in time diminish if ongoing practise is not maintained. The frequency with which nurses perform drug calculation in the clinical setting is decreasing. This study aimed to identify and analyze numeracy skills required by beginning registered nurses to facilitate development of numeracy skills by nursing students. A convenience sample of metropolitan and rural health care facilities in New South Wales (NSW) was selected. Within each facility an area where nursing graduates customarily work was selected. Numeracy input required to complete patients' charts was identified. Additional counting, measuring or computation the nurses performed was also identified. Except for paediatric areas, the frequency with which a nurse has to perform other than a simple calculation in order to administer a medication, or calculate a per minute drip rate is low. However, the necessity to calculate drug doses does exist. Creative ideas are needed to enable nurses to do this accurately. Three general approaches are suggested. A number of recommendations are presented.