Medication errors are unacceptably common and a review of the literature will leave the reader in no doubt that such errors present a real risk to patients in terms of morbidity and mortality. The aim is to give the right drug to the right patient at the right dose at the right rate for the right duration by the right route at the right time. There are a number of technologies that can impact at various stages of the medication process but no one safety technology can impact on all stages.
Medication safety systems include computerised physician order entry, pharmacy information systems, automated dispensing machines, bar code medication administration and smart infusion technology.
The various steps of the medication process are associated with different error rates: ordering 39%, transcribing 12&, dispensing 11% and administering 38%. Approximately half of ordering errors and one third of transcription and dispensing errors are detected before the drug reaches the patient, but Bates et al (1995) found that 34& of preventable adverse drug events (ADE) occurred at the point of administration, and that none of these were intercepted. Literature evidence demonstrates that the incidence of errors in the medication process for injectable medicines is higher than for other forms of medicine and 60% of these errors relate to IV infusion pumps.
Smart infusion systems are a relatively new yet under-utilised technology that provides an additional layer of protection at the point of drug administration to help avert errors and prevent patient harm. Although for maximal effect a number of medication safety technologies are required, smart infusion pumps can be introduced as a stand-alone technology and immediately impact positively on medication administration safety – the area where almost all errors will not be intercepted. The
National Patient Safety Agency states that for high-risk injectable products consideration should be given to the use of safer systems of administration such as 'smart' infusion pumps.
The term smart pump was originally adopted by the Institute for Safe Medical Practices (ISMP) to describe an infusion pump with an associated drug library that contains correct parameters for all medications to be delivered by the pump. That is, a customised data set is incorporated into the software that guides the clinician at the point of administration. This helps ensure that pump settings are within the institution's defined upper and lower limits for drug dosage, concentration, and infusion rate, and that drug loading and bolus doses are within institutional limits. Newer smart infusion systems increasingly communicate with other safety technologies such as barcode medication systems, electronic medication administration records and pharmacy information systems.
Standard infusion pumps will deliver whatever dose/time/concentration has been programmed into the device. The wrong touch of a button can programme a dose of 10mg/hr instead of 1mg/hr, or set the time of infusion for one hour rather than ten hours. A clinician would never give 100 tablets to a patient instead of a correct dose of one tablet, and yet 100-fold errors can be made when giving intravenous (IV) drugs via an infusion pump.
As stated IV medications as a whole carry the greatest risk, but continuous IV infusions are associated with an even higher potential for error and an even greater severity outcome. Calculations involved in delivering continuous infusions are more complex and more prone to error than those involved in intermittent dosing. A standard infusion pump will carry out instructions entered into the device no matter how erroneous they are thus increasing the potential for error. Errors are likely to
be maintained over the duration of the infusion, error detection may be delayed, and medications administered by continuous infusion tend to be more potent (such as vasoactive substances, sedatives, and narcotics) which means that medication errors have a higher likelihood of causing harm.
Flaatten and Hevroy (1999) showed that 32& of all medication errors were infusion related and Husch et al (2005) identified that 66.9& of IV infusions pump medications had one or more errors associated with their administration. Hicks et al (2003) found that 8.7& of medication errors involving infusion devices resulted in harm. The majority of errors were due to incorrect programming.
Pump errors categorised
Errors associated with the use of standard infusion pumps can be grouped into four main categories, although there is some overlap between categories.
Multiple of ten errors occur when an infusion is set up with a dose or time that is a multiple of ten higher or lower than the correct prescription. Eskew et al (2002) cited one example where the amount of morphine was entered as 100mg in 100ml instead of 1,000mg per 100ml. When the infusion device calculated the infusion rate based on the incorrect data input, the patient received a ten-fold overdose.
Unit errors are mistakes involving units of dose, weight or time, rather than simply the
addition or omission of a number of zeros. An example is an insulin infusion which should have been set up in units/hr, but was instead calculated in units/kg/hr, resulting in a 67-fold overdose.
Calculation errors occur where a mistake is made in calculating dose, rate or both. Examples are a vecuronium infusion that was calculated at 4.357mg/kg/hr instead of 0.05mg/kg/hr and an insulin infusion that was correctly set to infuse at seven units per hour, but miscalculated at the next dose to infuse seven units over five hours.
Push button errors occur when the user pushes a wrong button on the device when programming the infusion. In one example the infusion rate for a neonate was to be increased from 3.2 to 3.4ml/hr. The nurse unintentionally pressed the zero in place of the decimal point, resulting in an infusion rate of 304ml/hr instead of 3.4ml/hr. Hatcher et al (2004) cite a case where a nurse incorrectly entered 205 instead of 2.5 to deliver an 82-fold overdose of nitroprusside to a 3.3kg infant.
Benefits of smart pumps
Standard infusion pumps would not detect or prevent the above errors. However, these errors would be prevented by smart pumps with hard limits if the drug parameters entered into the pumps were outside drug library limits. Smart pumps can have soft and/or hard limits, and there has been much discussion in the literature about the risk/benefit profile of each setting. Hard limits cannot be overridden by the clinician operating the pump, whereas soft limits can.
Soft limits allow clinicians to make the ultimate decision about infusion parameters and in theory provide more flexibility. However, many consider they negate the purpose of a drug library, which is to keep infusion parameters within preset institutional drug limits deemed to be safe. Pratt (2004) evaluated a wireless smart pump system with soft limits for effectiveness and found that clinicians overrode 95& of 1,117 alerts warning the user that the requested drug delivery was outside drug
library limits. Only 57 alerts were not overridden, and 13 of these led to avoidance of harm when pumps were reprogrammed.
Obsheatz (2004) showed that, in the first two months of operation of a smart pump system, 26 overdoses involving high and moderate-risk medications were prevented. Following smart pump system introduction, data demonstrated that 12.4& of all warnings resulted in errors being averted when the original data entry was changed as a result of the drug library alert. When Vanderbilt University Medical Centre tested 50 smart pumps, 900 alert messages were produced, resulting in 99 potential
infusion errors being averted during an eight-month period. In another study smart pumps prevented near misses in 7.2& of all identified events.
Larsen et al, (2005) analysed the number of errors reported in the year before changing to smart pumps (2002) compared to the year after (2003). Hospital-wide errors reported with continuous medication infusions decreased by 73& after the introduction of smart pumps. The error rate decreased from 3.1 to 0.8 per 1,000 doses and the number of ten-fold errors decreased from 0.41 to 0.08 per 1,000 doses. Analysis of data from 18 institutions using smart infusion technology showed that, in an
average 350-bed hospital, IV medication safety systems avert a potentially life-threatening IV programming error every 2.6 days and a potentially significant IV error every 1.9 days (Maddox, 2004).
Healthcare organisations can compare using smart pumps to using seat belts. Unlike airbags, safety features that are not optional and cannot be bypassed by the user, seatbelts are an optional safety feature. They can be bypassed, as can dose-checking technology, despite a policy dictating their use. Even today there are reports in the literature of drug libraries being bypassed resulting in harm to patients. It is therefore essential that this technology is introduced, in its widest sense, into hospitals correctly, that users are educated in the technology, that drug libraries are fit for purpose and quickly modified as necessary and that a culture of safety avoids making clinicians bypass this safety feature.
Change creates uncertainty and discomfort but often leads to real innovation, providing opportunities for creating a better way forward. In addition to technology design, the manner of technology introduction into an organisation is paramount in its successful implementation – and this applies to smart infusion technology. An excellent paper by Karsh reviews the literature on diffusion of innovations, technology acceptance, organisational justice, participative decision making and
organisational change and provides strategies for promoting successful technology implementation. As Karsh says, healthcare organisations that ignore implementation design principles increase the risk that users will reject the technologies that could ultimately improve patient safety – a mistake they can ill afford to make given the cost of such technologies.
Improving patient safety is the aim of every healthcare organisation. There is little doubt that smart pumps can save lives if properly designed and used. That is, technology exists that protects both the patient and the clinician from drug administration errors. The question is – why are we not all using this technology? The Institute for Safe Medication Practices states, with respect to smart pumps, 'in the not too distant future, failure to use technology like this will likely
be considered suboptimal care.'
Research material has been referenced in this text. For full details please contact the editor, [email protected]