Accurate temperature monitoring of refrigerators and freezers is required to protect the safety and efficacy of medications, as well as to ensure compliance with TJC’s medication management standards. However, it can be challenging to ensure medications are continuously stored at the proper temperature when utilizing a manual process. Implementing a wireless temperature-monitoring (WTM) system ensures that medications are stored properly, and can prevent the loss of expensive medications should a refrigerator or freezer go out of range. 

New York Hospital Queens is a 540-bed, non-profit, community teaching facility that is part of the New York Presbyterian Healthcare System. Recognizing the importance of achieving full regulatory compliance, the hospital initiated mock accreditation surveys as a tool to gauge the success of our practices. These mock surveys identified that our method of manually documenting temperatures in refrigerators and freezers storing medication, nutrition products, and blood products was insufficient, and created the risk of a potential regulatory citation. Consequently, it was decided to implement a WTM system in critical areas throughout the hospital. 

Evaluating Our Current Refrigerators
Prior to commiting significant financial and staff resources to the implementation of a WTM system, existing units were evaluated to see if they were able to maintain the USP standards for medication storage. Unfortunately, we found that the majority of refrigerators in patient care areas were not capable of maintaining appropriate temperatures. Many older units had previously been replaced by small household units, which did not meet the temperature requirements for medication, blood, and nutrition products. Therefore, we requested and received budget to replace existing medication and vaccine refrigerators with medical-grade, under-the-counter programmable units.  

Wireless Temperature-Monitoring System Options
Several WTM systems were evaluated culminating in the adoption of one that best suited our needs. When identifying the ideal system, we chose one that utilizes wireless sensors connected to probes immersed in a bottle of ethylene glycol, which reduces temperature fluctuation and false alerts. Cost and the ability to self-install were also key elements considered.

Over 100 new, medical-grade refrigerator units were purchased; each of these could be programmed to maintain a stated temperature, which made manual log maintenance easier to manage as the WTM system was phased in over a one-year period. Once an area was integrated into the electronic process we discontinued the use of manual logs, with the exception of situations where network downtime exceeded 12 hours. In addition, because these refrigerators and freezers are designed for hospital use, they typically include ports or access points for inserting the temperature sensors, easing the installation process. 

Installation Process
Installation was managed jointly by IT and pharmacy. Implementing temperature monitoring requires the resources of multiple departments, not only during the initial implementation, but also to ensure effective, ongoing maintenance. Begin by installing the system in a few areas, and then expand once staff becomes familiar with the system. We chose to prioritize areas by need: the blood product storage area in the blood bank as well as the labor and delivery suite were the first areas chosen, followed by the pharmacy refrigerators and freezers, and then the medication and vaccine storage refrigerators on the patient care units. 

When implementing the wireless sensors, the connecting wire must be attached to an access point in the interior of the unit being monitored. Depending on the unit’s age, access ports may not be available. In our facility, the units in the blood bank and laboratory required either locating an access point or creating one. Some older storage units allowed the placement of sensor probes through the door hinge area with little complication, provided the sensor wire was properly secured using cable clips. We found that our vendor’s practical experience was a useful resource in identifying the best locations for the sensors. 

Initially, we opted to use wireless sensors with powered (120 volts) receivers. However, it quickly became clear that maintaining access to a power supply would be a challenge because most receivers are located above the ceiling where access to a 120 volt power supply is limited and requires the additional services and expense of an electrician. Our engineering department estimated that there would be a significant cost associated with transferring data from the sensor to the receiver. Thus, the powered receivers were swapped for  receivers that worked with our Ethernet  network, which resulted in significant cost savings.

Furthermore, signal strength dictates the number of receivers needed. Our institution comprises four main buildings, some of which were built in the late 1950s. Thus, the signal strength of the sensors in the oldest building was less than optimal and required the addition of multiple receivers to provide consistent readings. Basement areas also may require multiple receivers. 

It is important to note that a facility-wide, concurrent implementation of wireless smart pumps put a significant strain on IT and pharmacy resources, causing some delays in implementation. In retrospect, a more practical strategy would have been to complete one project at a time. In total, 174 refrigerators, freezers, and other critical areas are currently monitored (see TABLE 1). 

Collaborating for Success
A project of this magnitude requires collaboration from multiple departments. The director of pharmacy and the IT department manager jointly oversee the program’s software, hardware, and upgrades. The director of pharmacy notifies the IT department of any sensor or receiver issues and arranges for software upgrades as needed. IT maintains the receivers and servers, while the director of pharmacy and pharmacy staff is responsible for calibrating individual sensors, maintaining the status of the individual units, and overseeing battery replacement. 

It is also vital to maintain a close relationship with the WTM system vendor to ensure timely access to updates that will benefit your practice. Over time our vendor has offered several new options and updates, including monitoring of battery life that significantly reduced the resources required to replace batteries. This capability will be especially useful when we expand the system into our offsite clinics that close on nights and weekends. The user dashboard also has been updated making it easier to review system status. In addition, our system now utilizes a variety of sensors that can be used for specific scenarios, including non–ethylene glycol probes and pressure monitors that are used in our cleanroom to ensure USP <797> compliance. The non–ethylene glycol immersed probes provide less likelihood of spillage and evaporation.

Managing Alerts 
One benefit of our temperature-monitoring software is that it provides two types of alerts: yellow when the temperature is approaching the range limit, and red when the unit is actually out of range. The system allows a tiered alert structure, and sends alerts to primary, secondary, and then tertiary personnel if not addressed. An additional alert can be sent concurrently to the system manager and the director of pharmacy. 

Initially, we opted to transmit alerts by telephone. However, staff quickly became frustrated due to a ten-second delay prior to receiving the taped message, which caused many staff to hang up prior to hearing the message. Text messaging was also deemed impractical, as it would have required the institution to purchase a large number of cell phones, and management considered this cost-prohibitive. 

After careful consideration, we opted for email alerts sent to the manager in charge of the monitored area. Email notification was the most viable option because only the system manager is required to have a dedicated cell phone to monitor alerts during off-hours and weekends. 

System Maintenance
A primary maintenance issue is ensuring that batteries are replaced in a timely manner. Also, the system should be programmed prior to implementation to specify how often it will send a signal to the receiver. We programmed our sensors to send signals at least every 15 minutes; however, this frequent transmission of data drains battery life quickly and results in the need to replace batteries every six months. Another concern is that our system does not allow automatic reprogramming via the software. Thus, each individual sensor requires reprogramming with special software and a mobile PC in order to change any sensor programming. In the future, we hope that migration to the next generation of sensors with a software upgrade will help resolve this issue.

Benefits of Wireless Temperature Monitoring
Regulatory Compliance
In March 2013, we had a Joint Commission survey. After providing the surveyor a brief overview and description of the WTM system, he requested a demonstration of the alert process. Rather than leave a pharmacy refrigerator door open to trigger an alert, we opted to reprogram the acceptable range on one unit in the pharmacy to a narrower limit that would trigger an alert. The alert was received via email and on the director of pharmacy’s cell phone within two minutes. The surveyor was impressed with the system’s response time, and we received no further questions regarding our temperature-monitoring process. 

We also received a scheduled visit from the New York City Department of Health and Mental Hygiene regarding the Vaccines For Children (VFC) program. The inspector reviewed and approved our calibration method for the individual sensors. Calibration is accomplished using a certified, ultra-sensitive thermometer or humidity meter while observing the actual sensor reading. We also were able to provide a three-month printout of all monitored VFC storage units from our database. The inspector was impressed with the monitoring capabilities of the system for our dedicated VFC refrigerators and freezers.

Reporting Capability
It is recommended to choose a system that has a variety of reporting and documentation functions. Our system allows individual sensors to be viewed daily, monthly, or over a defined time span, with or without graphics. This ability has proven effective in meeting the standards of pharmaceutical companies who utilize our site for clinical trial studies. Many clinical studies require critical range temperature monitoring which would be time-prohibitive using a manual process. 

Cost Savings
A WTM system can provide significant cost-savings in the event a refrigerator or freezer goes out of range. Despite proper maintenance and testing, one of the medical-grade refrigerators in our onsite pediatric clinic recently went out of range, triggering an alert. This refrigerator primarily stored vaccines for the VFC program. Due to the timeliness of the alert and our subsequent intervention, $12,000 worth of vaccines was saved.

Future Goals
We are currently conducting pilot programs utilizing our WTM system. The first involves monitoring temperatures in the fluid warmers in the ambulatory surgery suite, which consists of nine ORs and a hybrid vascular room. Each of these rooms has a fluid warmer that requires a manual log sheet to document temperature of IV and irrigation fluids. Our fluid vendor provided us with revised expiration dates of their fluids under elevated fluid warmer temperatures. If we experience success monitoring temperatures in the warmers in the ambulatory surgery suite, we plan to take a similar approach in the inpatient OR as well as labor and delivery suites in the first quarter of 2014.

The second pilot program currently in progress is the monitoring of ambient room temperature and humidity in the ORs, ambulatory surgery, and central sterile distribution. Initially, this pilot has been a success and it will be fully implemented by the second quarter of 2014.

Conclusion
WTM is a key asset in our hospital’s effort to maintain regulatory compliance for the storage of medications, nutrition, and blood products. The system’s robust alerting and reporting capabilities have been instrumental in contributing to our accreditation success with TJC and VFC. Moreover, the system provides peace of mind that we are providing patients with medications that have been stored at the proper temperature and will function as intended.

Alexander F. Melchert, MS, RPh, is the director of pharmacy at New York Hospital Queens. He received his bachelors degree in pharmacy from the Brooklyn College of Pharmacy and his masters in clinical pharmacology from St. John’s University School of Pharmacy.

TABLE 1. 
Areas Managed by WTM at New York Hospital Queens

• All patient care area medication storage refrigerators including operating rooms and diagnostic procedure areas
• All vaccine refrigerator and freezer storage areas
• All pharmacy medication and investigational drug storage areas
• All patient care area nutrition refrigerators
• All blood product storage including refrigerators, freezers, and plate warmers
• Onsite pediatric clinic vaccines
• Breast milk storage areas
• Food and nutrition kitchen
• Laboratory refrigerators and freezers
• IT data closets and server rooms
• Pilot monitoring of ambulatory surgery fluid warmers
• Pilot monitoring of ambient temperature and humidity in the OR, ambulatory surgery suite, and central sterile distribution