(BOOK) DRUG CALCULATIONS FOR NURSES A STEPBY-STEP APPROACH 3RD Edition By ROBERT LAPHAM

DRUG CALCULATIONS FOR NURSES A STEPBY-STEP APPROACH 3RD Edition By ROBERT LAPHAM. PROMOTING THE SAFER USE OF INJECTABLE MEDICINES The risks associated with using injectable medicines in clinical areas have been recognized and well known for some time. Evidence indicates that the incidence of errors in prescribing, preparing and administering injectable medicines is higher than for other forms of medicine. As a consequence the National Patient Safety Agency (NPSA) issued safety alert 20: Promoting Safer Use ofInjectable Medicines in March 2007. The alert covers multi-professional safer practice standards,with particular emphasis on prescribing, preparation and administration of injectable medicines in clinical areas. The NPSA has produced a risk assessment tool which highlights eight risks associated with the prescribing, preparation and administration of injectable drugs. There are two risks that highlight the involvement of calculations and so emphasize the need to be able to perform calculations confidently and competently; these risks are: • Complex calculations: any calculation with more than one step required for preparation and/or administration, e.g. microgram/kg/hour, dose unit conversion such as mg to mmol or % to mg. • Use of a pump or syringe driver: all pumps and syringe drivers require some element of calculation and therefore have potential for error and should be included in the risk factors. However, it is important to note that this potential risk is considered less significant than the risks associated with not using a pump when indicated. Each injectable drug in use within a particular hospital needs to undergo a risk assessment using a set proforma. Once risks have been identified, action plans need to be developed to minimize them. Hospitals must ensure that healthcare staff who prescribe, prepare and administer injectable medicines have received training and have the necessary work competences to undertake their duties safely. This will include IV study days which will teach and assess nurses so that they are able to prepare and administer injectable drugs – part of these assessments will involve drug calculations. References Injectable Administration of Medicines (2007). Pharmacy Department, UCL Hospitals. Blackwell Publishing: Oxford, 2nd ed. 138 Action and administration of medicines Injectable drug risk assessment proforma Final volume Bag/syringe Therapeutic Use of concentrate Complex calculation Complex preparation Reconstitute vial Part/multiple container Infusions pump or driver Non-standard infusion set Risk assessment score Risk reduction method(s) Revised score Risk factors Directorate: Date: Strength Diluent Prepared injectable medicine Risk assessment summary for high- and moderate-risk injectable medicines products Risk assessment undertaken by: Name of pharmacist: Name of clinical practioner: Problems139 PROBLEMS Write down the volume as indicated on the following syringes for oral use: Answers can be found on page 215. 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1 mL syringe Question 2 1 mL syringe Question 1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 1 mL syringe Question 3 0 0.1 0.2 0.3 0.4 0.5 0 1 2 2.5 0.6 0.7 0.8 0.9 1 1 mL syringe Question 4 0 1 2 3 4 5 6 7 8 9 10 0 1 2 3 4 5 6 7 8 9 10 10 mL syringe Question 10 10 mL syringe Question 9 2 mL syringe Question 5 0 1 2 2.5 2 mL syringe Question 6 0 1 2 3 4 5 5 mL syringe Question 7 0 1 2 3 4 5 5mL syringe Question 8 10 INFUSION DEVICES OBJECTIVES At the end of this chapter, you should be familiar with the following: • Gravity devices • Pumped systems • Volumetric pumps • Syringe pumps • Patient-controlled analgesia (PCA) • Anaesthesia pumps • Pumps for ambulatory use • Infusion device classification Various devices are available. Gravity Devices • These depend entirely on gravity to drive the infusion; flow is measured by counting the drops. • A gravity device should be considered only for low-risk infusions such as sodium chloride, dextrose saline and dextrose infusions. • A gravity device should not be used for infusions: • containing potassium; • containing drug therapies requiring accurate monitoring or delivery of accurate volumes; • delivered to volume-sensitive patients. Pumped Systems These include the following different types: Volumetric pumps • Preferred pumps for medium and large flow rate and volume infusions; although some are designed specially to operate at low flow rates for neonataluse (not recommended for <5 mL/hour). Syringe pumps • These are used to administer drugs or infusions in small or medium volumes, and are calibrated at rates of 0.1 to 99 mL/hour (recommended for <5 mL/hour). • Syringe pumps are used extensively where small volumes of highly concentrated drugs are required at low flow rates: usually in intensive care settings. KEY POINTS INTRODUCTION This chapter is not meant to be an exhaustive review, but is a brief overview of the different infusion devices available and their use in drug administration. The reader is advised to seek more detailed references and to read the manufacturers’ manuals for advice on setting up and using infusion devices, and problems associated with them. In general, infusion pumps are capable of accurate delivery of solutions over a wide range of volumes and flow rates, and may be designed for specialist applications, e.g. for neonatal use. For assistance with online tutoring and help with assignments with guaranteed pass contact: