Medication errors are any preventable events that may cause or lead to inappropriate medication usage. This ends up harming the patient since the medication is in control of the health care professional, or consumer. Such events may be related to professional practice, health care products, and procedures including prescribing which occur in chemists or even in hospitals caused by pharmacists in charge. This can also be led by; dispensing, distribution, administration and poor monitoring (NCC MERP, 2005).
According to J.K.Aronson, 2009, the medication errors have many classifications, which include:
1 Contextual classification: The classification here made according to the specific time, place, medication and people involved.
2 Modal classification: The errors analyzed according to the way it happened.
3 Psychological classification: The classification based on explaining events. It is the most recent, preferred one. It involved four types of errors including :
* Knowledge-based errors that happened due to the lack of knowledge (e.g. giving or prescribing a medication without having established whether the patient is allergic to it or not.
* Rule-based errors which can be further classified as either the misapplication of a good rule (e.g. injecting a medication in to non-preferred site) or the application of a bad rule or the failure to apply a good rule (e.g. using excessive doses of a drug).
* Action- based errors (slips error) which can happen through incorrect performance (e.g. writing Chlorpropramide instead of Chlorpromazine). These errors include the technical error.
* Memory-based errors (lapses) which happened by forgetting (e.g. giving a drug that a patient is already known to be allergic to.)
As mentioned before, the medication errors can occur in any step in the medication use cycle, i.e. at the stage of prescribing, dispensing or administration of a drug.
The prescribing errors defined as the incorrect drug selection for a patient (DJP William, 2007). It includes wrong dose, quantity, indication or prescribing of a contraindicated drug. Many factors lead to this kind of errors including:
- Lack of knowledge (drug dose, patient details).
- Illegible handwriting.
- Confusion with the drug name.
- Using of abbreviation.
- Inappropriate use of decimal points.
- Work load and environment.
- Inadequate training.
- Communication problems.
These errors can be intercepting by using of computerized prescribing system, bar coded medication system, education, and double-checking.
In the dispensing process, errors happened in any stage of this process starting from receiving the prescription ending by supplying of the medications. It may include the dispensing of a wrong drug (Lasix instead if Losec), wrong strength, wrong dose, wrong labeling, to the wrong patient. Many factors may result in these kinds of errors including: transcription errors, high work load, inexperienced staff, similar packaging, storing the drugs that look alike near each other in the shelves. The double- checking, staff training, and providing a suitable environment for dispensing in order to reduce the incidence of such errors (DH, 2004).
Administration is the stage of the medication using process that presents multiple opportunities for errors. The errors happen when there are differences between the drug received by the patient and the drug therapy written by the prescriber. It involved dose omission, incorrect administration technique, wrong administration time, wrong preparation and wrong patient (William, 2007). Administration errors may happen for the same reasons mentioned in the two previous processes. In addition to that, any error in the prescribing or dispensing steps may result in an administration error if not detected immediately (DH, 2004).
The intravenous route of drug administration is a complex process it often results in the most serious outcome of medication errors (Barber, 2003). Many studies defined IV medication error as any deviation of preparation or administration of an IV dose from the original prescription or any act in the preparation or administration. This is deviated from the manufacturer's instructions or the hospital drug policy (Barber, 2003) Studies have been done in to the use of IV drugs and related medications errors. Two ethnographic studies investigated the causes, the incidence and severity of IV drug error in two UK hospitals .These studies found a high incidence of errors in preparation and administration processes of IV drugs, some of them were serious. The main causes of IV error were deliberate violation of guidelines, 98% of this violation was fast administration of bolus doses. Other causes include design failure of technology, workload and lack of supervision (barber, 2003).
Another study has compared errors in the UK teaching hospital and two Germany teaching hospitals. Out of 278 observations, there were 93 (34%) administration errors. The most common type of error was rate of administration error 27% in UK, 49% and 22% in Germany hospitals. Other errors identified were wrong dose, omissions, compatibility errors and patient identification errors. In the two countries, the medication errors had moderate to severe outcome (Wirtz, 2003). Similar results were observed from an audit conducted in three countries; UK, Germany and France that compare the effect of health system design on the number of observed IV medication error. The wrong rate was the most common error 49% in UK, 21% in German and 5% in France. Other errors were: wrong dose, wrong volume, wrong route and wrong time (Cousins, 2005).
Some of these studies suggested the use of good equipment designs, staff training and coordination between practitioner and regulator and pharmaceutical industry in order to reduce the IV errors occurrence (Barber, 2003).
The NHS has set out many recommendations in order to reduce the risk of drugs administration errors. This includes; the application of five "rights"s to check directly before medication administration: right medication, in the right dose, to the right patient, by the right route and at the right time. In addition, the hospitals trust should have standardised infusion equipments and these devices should be simple to setup, easy to use and have good safety features. .The joint commission on accreditation of healthcare organizations (JCAHO) has broadened its patient safety standards .These goal are to change the system and make it easier to do the right thing, prevent individuals from committing errors, and building highly reliable organisations. In order to achieve this goal, JCAHO recommend the usage of technology.
Types of infusion devices:
1 Gravity controlled.
These kinds of infusion devices rely on gravity to regulate the rate of flow. They are useful for lower risk application like fluid replacement therapy. The fluid container should be placed high above the infusion site. There are two types in this category: drip rate regulator and drip rate controller.
2 Infusion pump.
These devices are used in an active method to overcome resistance of flow by increasing delivery pressure.
An infusion pump is a medical device that delivers fluids, such as nutrients and medication (including high-risk medications) in to a patient's body in controlled amount. They are used in both hospitals and home setting and were introduced to healthcare industry over 30 years ago (Ronald D, 2005). They are many types of infusion pumps such as; drip rate pump, volumetric pump, syringe pump, multi-channel pump, and ambulatory pump. The most common used in the UK is volumetric and syringe pumps (MHRA, 2010).
Volumetric pumps are used for medium, high flow rate and also for the large volume IV. This pump can calibrate in ml per hour or microgram per kilogram per hour. It has an advantage in delivering accurate infusion volume. However, its disadvantage is that it's an expensive device, as it needs special IV infusion sets of standard size.
Syringe pumps are the most common used since they are accurate, cheap, and suitable for small volume and low flow rate infusions. It should place approximately level with the infusion site. The disadvantage of this type of pump is that it is not suitable for large volume.
Infusion pumps have many advantages compare to manual administration such as:
* They can deliver medication in very small volumes
* They can deliver medication at programmed rates.
A study done by M.G.A in 1983 examined six infusion pumps, three piston volumetric, and three peristaltic pumps showing that all pumps provided accuracy and consistency of volume delivered. However, these results depended on the correct calibration of these pumps before their usage. Furthermore, it was not possible to guarantee the accuracy of the pumps during accidental occlusion of the IV tubing. In addition, the study showed that in the event of extravasations these pumps continued to infuse the fluid.
A report from the Department of Health by the Chief Pharmaceutical Officer investigated the causes and the frequency of medication errors. This report also provided empirical solutions derived from clinical experiences in the UK and North America, in order to reduce this risk and promote good practice. According to this report, there were 6773 adverse incident reports related to infusion devices between the year 1990 to 2000, 1495 reports with infusion pump were identified. In half of these reports, the cause of patient ending up being harmed could not assess. In the other half, the most common errors were user error 19%, equipment performance 8%, design/labeling 5%, quality assurance 5% and damage 5%.
The most common type of user errors associated with infusion devices were: wrong rate, compatibility error, secondary infusion errors, and free-flow of therapeutic drug in to the patient. The direct cost of medication errors in NHS hospitals trust is between 200-400 million pounds per year, not to forget the unknown cost of errors in primary and community setting. As mentioned before, infusion pumps frequently use to administer critical medications. Pump failure can have significant implication for patient safety. Data from FDA showed that around 56,000 adverse event reports received in the period from 2005 to 2009 were associated with the usage of infusion pumps. The reports included injuries to patients and also leading to death. As a result, 87 infusion pumps were recalled (FDA/medical device).
Some new infusion pumps called smart pumps include software which allows the hospital to set dilution, and dose/infusion rate limits which cannot exceed during administration. These pumps prevent infusion when dose exceed the limits, they change setting by patient type and access to transaction data for quality-improvement efforts.