Pharmaceutica Analytica Acta

In this paper we will show the design of a device that is intended as a solution for reducing the number of Adverse Drug Events (ADEs) related to drugs administration to patients. The device is a container that incorporates an RFID (Radio Frequency Identification) reader in order to perform a check on patient's identity and to allow the administration of medications only to the right patient.

Many studies can be found in literature on this subject, assessing the problem of human factors in medication administration errors. Part of them are based on data coming from incident-reporting, others apply proactive analysis tools such as FMEA (Failure Modes and Effects Analysis) or HTA (Hierarchical Task Analysis). The National Coordinating Council for Medication Error Reporting and Prevention defines a medication error as "any preventable event that may cause or lead to inappropriate medication use or patient harm while the medication is in the control of the health care professional, patient, or consumer. Such events may be related to professional practice, health care products, procedures, and systems, including prescribing; order communication; product labelling, packaging, and nomenclature; compounding; dispensing; distribution; administration; education; monitoring; and use [1]." Adverse Drug Events (ADEs) are defined as injuries resulting from the use of a drug. Under this definition, ADEs include damages caused by the drug (adverse drug reactions and overdoses) and damages from the use of the drug (including dose reductions and discontinuations of medication therapy) [2].

According to [3,4], the 28% of all the ADEs come from the medication administration step.

Technological solutions, such as radio frequency tagging has been widely suggested as a solution to the problem of the wrong identification of patients and of the incorrect association between patient and medications.

In this work we are focusing on the error in the administration step, defined as the change between what the physician's prescription and the actual medication administered to the patient. Medication errors that originate from mistakes during prescribing can be significantly reduced by using CPOE (Computerized Physician Order Entry) software, thereby solving problems related to incomplete orders, bad calligraphy, misunderstandings in abbreviations, incompatible drugs etc. Nevertheless, CPOE use itself cannot prevent that the medication that is actually given to the patient is different from what the doctor prescribed. We can notice a lack in patient's safety in the last step of the whole therapeutic process: the administration step.

Some authors claim that use of Barcode Point-of-Care Technology (BPOC) to reduce medication errors is a patient-safety approach that hospitals can implement within a short time frame and obtain immediate benefits [5]. Some claim that the integration of bar codes and radio frequency identification tags are viewed as critical in achieving effective and safe patient care although systems using these capabilities must be carefully planned to achieve optimal outcomes [6-8].



We started the design process by spotting 28 requirements to which our device must respond (see Table 1) and generating 20 corresponding technical specifications (see Table 2). The identified requirements relate to aspects of process safety as well as to procedural aspects and usability. Also affordability is an issue, to guarantee the widest dissemination of our device in hospitals.

Table 1: Requirements and corresponding technical specifications.

Table 2: Technical specifications.

The device, based on above requirements and technical specifications, is a container with an electronically operated lock that opens only when the opening attempt is performed by the patient to whom the drugs are destined (or by healthcare staff), thus dramatically reducing the chance of wrong administrations. The device integrates a custom miniaturized RFID reader operating at 13.56 MHz for the recognition of the patient and/or operator that must wear a simple and cheap passive ISO 15693 compatible wrist band. The compliancy to this standard guarantees maximum compatibility to bracelets commercially available.

As shown in figure 2, the device incorporates an internal tag that will contain information about the patient's identity and his drug therapy. This solution has been preferred to flash memories because in this way we can read/write on this "internal memory" using the onboard electronic card or a standard external RFID reader without any wired connections. Each attempt to open the device (successful or not) and each consequent alarm is logged using this internal tag as an on-board memory. The device is also provided with an USB port, but this is used just for battery recharge and for firmware maintenance.

Figure 2: Block diagram of the device components.

As stated in specification S.5 (see Table 2), the container is provided with two LEDs, a red one and a green one, to give feedback to the user about the correct patient-drugs matching.

The technical specification S.15 is satisfied by providing a small 16 × 2 display. This is used to show the name of the patient for which the device has been prepared for, and to display the list of drugs prescribed to the patient.

The firmware is also able to read the drugs inserted into the device (provided that they are tagged with RFID) and to prevent its opening if some un-prescribed drug is found inside the container, alerting the patient/operator using the on-board display (Figure 3).

Figure 3: The RFID drug container.

The patient himself can easily operate the presented device, since its input interface consists of a single button, to be pressed after placing the device in proximity of the RFID wristband. It is also possible, for caregivers, to force the opening by using their own RFID badge. All these operations are logged in the internal tag and can be wirelessly sent to a central HIS (Hospital Information System).

By logging the number of granted/denied openings, the device could feed a Hospital Risk Management System, providing the risk manager with some valuable data to assess the quality of the medication service. If inserted in a CEP (Complex Event Processing) system the proposed device could significantly increase the patient's safety as well as the knowledge of the process by the hospital executives.

The ideal usage scenario provides an interface between the device and the hospital information system and CPOE and with an automated pharmacy that provides single dose RFID-tagged medications. In this setting, the device can easily signal mistakes in the preparation before the wrong drugs can reach the patient. It will also prevent openings in this case.

Future works include improving the performance of the antenna, realizing a mechanical prototype and analysing the domestic scenario for possible use of the device at home.

Author thanks Lorenzo Baroncelli, Aldo Manetti and Giovanni Burchietti for the big effort profused in this project. Heartfelt thanks goes to prof. Biffi for the expert help.