The Effects of Severe Weather on Medical Devices
MedSun: Newsletter #88, September 2013
Severe weather-related events can have an impact on the operation of medical devices in health care settings and in the home. In June of 2012, an intense fast moving thunderstorm called a “derecho” occurred crippling many Mid-Atlantic and Midwestern states by causing widespread damage and power outages. The effects of Hurricane Sandy in October of the same year were devastating to homes and healthcare facilities throughout the Northeast causing many power outages that also resulted in unexpected closures of hospitals.
FDA is interested in learning more about the effects of severe weather or storms on medical devices in health care facilities. The information helps the FDA to better understand the clinical perspective and the issues presented in hospitals in austere weather conditions. Feedback from health care providers also helps with determining how to best address the risks and vulnerabilities of medical devices in severe weather particularly when conditions result such as power and network outages, interruptions to transportation, lack of access to fresh water, contamination of water, and temperature and humidity variances.
This survey effort addresses how extreme weather events and conditions may affect the safety and quality of medical devices. Survey data was collected using a semistructured questionnaire by telephone with respondents. A small sample of respondents was selected to obtain detailed and in-depth perspectives about experiences with medical devices in the clinical setting during and after severe weather events.
The respondent sample was a voluntary, convenience sample of nine health care providers from hospitals that participate in the Medical Product Safety Network (MedSun) and who have experience with severe weather events in healthcare facilities. Respondents include Directors and Managers from departments of Clinical and Biomedical Engineering, Quality and Risk Management, Plant Operations, and Materials Management. Several respondents also serve on their hospital’s Emergency Preparedness Committees. Respondents’ hospitals are located in the Northeast, Mid-Atlantic, Southeast and Midwest regions of the country.
The survey questions (see attachment) focus on experiences with medical device performance, types of products affected, challenges encountered, and suggestions for improvement to manage the effect of severe weather on medical devices more effectively in the future. When FDA required clarification to a response, additional questions were asked.
The information that follows is a summary of the responses.
Experience with Severe Weather Events
All survey respondents have experience with power outages during severe weather events and have relied on backup electrical power by generators. The severe weather events include hurricanes, tornados, severe thunderstorms, microbursts, lightning strikes, heavy rain causing flooding, extreme heat and cold situations, and earthquakes that have affected some medical devices and general operations in their hospitals. One respondent also describes losing power in the hospital when a section of the city’s area power grid went dark causing their emergency generator to turn on. In a few situations during severe weather, respondents have experienced damage to the backup generator and add that the “dirty power” (spikes or fluctuations in voltage) from the emergency generator resulted in batteries not recharging in medical devices.
A power loss in one hospital due to a tornado also caused damage to the emergency power supply. This event caused overheating of the computerized central monitoring systems in a room where the servers and other equipment are stored. In addition, the air conditioning (AC) system did not work and there was a loss of power to monitoring equipment, imaging systems, and the computer systems for the hospital. The respondent in this situation refers to it as a potential meltdown that almost resulted in an evacuation of the facility. Another respondent recounts a time when a power loss affected exhaust fans that help to provide positive air pressure in specific rooms used for bone marrow transplant patients. Evacuation of the hospital would have occurred if the outage continued for a longer time creating an unsafe situation for patients.
In another occurrence, the impact of a severe storm and subsequent power loss resulted in an influx of people into the hospital’s emergency room with medical equipment that they could not keep charged in their homes. In addition, some individuals did not bring all the device components required for battery recharging. According to the respondent, this situation was occurring across the city. The respondent reports that the primary device problem involved home use oxygen. Individuals in the home had to switch to using oxygen tanks, but because supply companies weren’t able to deliver replacements, individuals went to hospital emergency rooms when their oxygen tanks were empty. The respondent adds that other home use devices affected by the power outage involved continuous positive air pressure devices (CPAPs), ventilators, portable suctions devices, and left ventricular assist devices (LVADs). Although in this situation many home care patients went to hospitals to obtain a power source for their devices, this respondent’s facility also maintains a 96-hour supply of equipment and devices such as ventilators and portable suction, if needed.
Many respondents report experiencing problems when the facility’s power is turned back on and results in a power surge. In one situation, the power surge burnt an AC compressor. In two other facilities, tomography, mammography and other radiology equipment failed as a result of a power surge. All survey participants discuss the importance of a controlled power-up and the impact it can have on devices particularly if devices are powered on at the time of a power loss; even if surge protectors are used. If the biomedical and maintenance departments work together to coordinate when the power is scheduled to turn back on, the changeover may not impact medical devices. Respondents believe that a controlled power-up is essential for some devices such as imaging devices, and communication and coordination among departments is critical to ensure patients are not receiving imaging procedures at the time.
When asked about generator testing, most respondents say they do routine testing. Three specify they do monthly testing. Several individuals conduct all tests as a full load test while others only do full load testing during hot weather. In addition, most respondents report that their hospitals’ emergency generators are located on the second floor above the flood plane.
Uninterruptable Power Supply (UPS) Systems
All respondents use uninterruptable power supply (UPS) systems for small devices and some have larger UPS systems that power areas such as the catheterization labs and where Information Technology (IT) server systems are located. UPS systems can provide near-instantaneous power when power disruptions or outages occur. One respondent currently uses UPS systems for magnetic resonance imaging (MRI) and other high-end radiology equipment after experiencing frequent power fluctuations and outages from severe storms and a lightning strike to a power line. Several respondents say they use UPS systems to bridge time until emergency generators turn on for critical equipment. One respondent believes that physiological monitoring devices and all critical devices whether they are hardwired or wireless should be on UPS systems and emergency power. The respondent adds that this approach helps stop normal power glitches particularly during emergencies. Another respondent emphasizes the importance of UPS systems for specialized high frequency ventilators so that if the power goes off and the emergency power fails, the UPS has 30 minutes of power for providing ventilation to patients.
The majority of respondents test and replace the batteries in UPS systems routinely and believe this maintenance is key to preventing device failures. Respondents also report that not all UPS systems are the same and some may have a shorter lifetime than others. Most respondents say they do battery replacement more frequently than the manufacturer’s recommendations. Overall, respondents believe selecting the right UPS system is critical and that they work well for medical equipment from the perspective of safety and reliability.
Types of Medical Devices Affected by Power Outages
Table 1. Summary of Medical Devices Affected by Power Outages Due to Severe Weather Events As Reported by One or More Survey Respondents
|Device Name/Device Area Affected||Problems Identified||Additional Information|
|Bedside monitors||“Dirty power” prevented batteries from recharging.||Bedside monitors “flickered” often while power was switching back and forth from normal to emergency power.|
|Bone Density Scanner||Device shut off due to a lightning strike to the power supply and would not turn back on.|
|Catheterization Lab equipment (not on emergency power)||Loss of visualization occurred during one procedure.||Staff determined the need for approximately 10 minutes of battery backup time to prevent reoccurrence. The facility added emergency power capability to the generator.|
|Central monitors||“Dirty power” prevented batteries from recharging. Over time devices went blank.||Central monitors were most affected.|
|Computerized centralized monitoring system (in a room where servers and other equipment located)||Overheating occurred and loss of monitoring equipment, imaging systems, and computer systems.||Overheating did not cause damage to devices.|
|CT Scanners (cooling mechanisms for scanners not on emergency power)||Excessive room heat caused an error and the software alerted staff to the increased heating of the scanner.||Staff brought in an air conditioner system to cool the room temporarily. Another facility placed their ventilation system on emergency power.|
|Incubators/isolettes in the neonatal intensive care unit||The heat settings reverted to the manufacturer's default setting posing risks to patients. The memory batteries (similar to watch batteries) wouldn't hold settings when power was restored.||Nursing staff noticed the change and corrected the settings. No adverse events occurred. The devices are older models with older memory batteries. Memory battery functionality is now part of Preventive Maintenance (PM) checks.|
|Linear accelerator (not on emergency power)||Device could not be used.||Outage lasted for several days and patients had to go to other facilities for treatment.|
|MRI (not on emergency power)||Loss of cryogen/helium and failure of the cold head due to the heat change occurred in the magnet.||Power outage lasted for a few days. However, a power loss for 2 weeks would cause quenching of the magnet.|
|Sterilizers (not on emergency power)||Devices could not be used.||When power was turned back on, test loads and test controls had to be repeated affecting the timing of OR cases and availability of equipment.|
|Telemetry units||Functionality was affected.|
|Tomography, mammography units||“Equipment failure occurred due to power surges.|
|Ultrasound unit||Device was damaged due to a power surge.|
|Ventilators||All piped gas supply was affected which impacted ventilators.||Facility used oxygen tanks for patients.|
Respondents mention several devices that were affected by power outages in their facilities due to severe weather conditions. Table 1 is a summary of these medical devices and the problems encountered. According to respondents, devices in the radiology department are affected by outages most times; however, devices in other areas can also be affected. Most critical devices used for acute monitoring of patients and defibrillators have backup batteries. Additionally, when discussing problems, respondents report that many devices were not on emergency power at the time of the outage, but now have emergency back-up power.
Respondents say that infusion pumps are less problematic because of the battery backup in the devices. However, one respondent emphasizes the importance of not using third party batteries for infusion pumps because the failure rate can be very high. This particular individual also uses a monitoring device for infusion pump batteries and conducts thorough testing procedures.
One hospital respondent describes difficulties with the Electronic Medical Records (EMR) system during a severe weather event. Clinicians could not access patient records because the medical records server shut down. Staff had to rely on the system at an affiliated hospital to send the forms they needed by facsimile.
Most respondents say that weather conditions such as thunder has not been a problem, but wind and lightning have the most effect on a facility’s power. Good routing grids on roofs (for lightning suppression) and lightning rods on buildings help to prevent severe damage to hospitals. However, a lightning strike in one building did result in a loss of telecommunications equipment. In this particular situation, the respondent thinks the equipment did not have a UPS system and damage to the equipment was due to a power surge. Another respondent says there are additional rods on their buildings to prevent damage to medical devices after experiencing power surges from lightning strikes.
In response to a question about alarm activation in medical devices during severe weather, the majority of respondents did not recall any particular problems. One individual remembers alarms only from the UPS systems that were running on batteries because they didn’t switch to generator power. In this situation, a new microprocessor switch corrected the problem.
Four respondents describe disruptions to their hospital’s communication system during power outages due to hurricanes, earthquakes and severe storms. All report that communication devices such as pagers, cellphones and two-way radios had weak signals from damage to cell phone towers. Cell phone texting is viewed as the best way to communicate and more effective for communication between Emergency Medical Services (EMS) and emergency room staff. One hospital has its own communication system on site where all antennas reside, but use of the system requires staff training if used as a backup method. Staff is also more familiar with the use of cell phones for communication than a pager system. Another respondent’s hospital that has affiliate sites, is in the process of developing a mobile communications vehicle with satellites, radios, communication resources, etc., that will be used to bring resources into a building to provide temporary relief until communications is restored to the hospital.
When respondents mention staff training, it’s usually in the context of reinforcing the importance of keeping battery-operated medical devices plugged-in when not in use so the battery is charged. One respondent describes a situation when patients were transferred to other hospitals due to a severe weather event and the receiving staff was not as familiar with the infusion pump devices accompanying patients. Additionally, some of the tubing brought in with patients was not compatible with the products the hospital uses. This particular respondent asserts that this type of situation may have implications for training.
A few respondents mention supply chain issues during a serious weather event. One respondent is going back to having an inventory and keeping a backup of supplies on hand for severe storms. One facility is in an area that floods frequently and depending on the extent of the storm can be inaccessible to supply trucks. The respondent for this facility maintains close contact with the distribution chain and adds that the hospital’s backup supply is sufficient to provide what is needed if area flooding occurs.
Suggestions for handling future challenges
The following is a list of suggestions from respondents about managing future challenges with the effects of severe weather events. Suggestions include approaches for hospitals, the community and device manufacturers.
• Provide staff with a better understanding of critical medical devices and equipment including weaknesses and vulnerabilities;
• Alert staff to environmental warnings, conditions, and device vulnerabilities, if available in the device labeling;
• Encourage a thorough knowledge of the facility and where staff and patients may need to go first to avert a catastrophe;
• Provide emergency supply bags throughout the hospital with items such as flashlights, gloves, first aid kits, batteries, headlamps, etc., for any staff to use during a weather emergency; and,
• Make improvements to the emergency power distribution in the hospital.
• Determine how to deal with situations when the city’s water supply is affected and impacts water pressure for health care facilities, dialysis centers and patients receiving home dialysis;
• Increase awareness and focus on the medical needs of patients in the community before, during and after a severe weather event;
• Determine ways to prevent vendor interruptions particularly with oxygen supplies for home use;
• Improve communication systems in communities so people know where to go during a crisis such as a severe weather event; and,
• Establish a registry of people in the community and the home medical devices they use to direct assistance to them quickly and avoid a large influx of people to hospital emergency rooms.
• Incorporate standard labeling on devices to alert hospital staff to environmental warnings, conditions, and other device vulnerabilities; and,
• Design medical devices with built-in UPS systems.
Overall, respondents have concern about the impact of severe weather on their hospital’s medical devices and equipment and the potential for harm to patients. Although respondents did not mention situations involving patient harm, they discuss device problems, challenges and the potential for harm that exists when their facility experiences a severe weather event. Respondents have procedures in place in the event of austere weather conditions but add that improvements are needed to meet challenges they encounter such as inoperability or damage to devices and patient monitoring systems, disruptions to communication systems, the need for increased patient monitoring by staff, and the impact on the surrounding community that can affect hospitals. In addition, a respondent mentions that following a weather-related disaster situation, it would be helpful to know at what point a hospital can or should use the equipment again. The respondent adds that even if medical devices are functioning after being affected by a severe weather event, is it sufficient to say that they are considered operational? Also, how do hospitals determine whether medical devices are still safe to use? Biomedical department staff are relied upon to help make those decisions but additional information may be needed to determine whether medical devices should be restored and recertified after being affected by a severe weather event and are determined to be safe for patient care.
Although the survey findings add to FDA’s knowledge of the effects of severe weather on medical devices, there are several limitations to the survey methodology. These include the small, convenience sample of respondents, and that most survey respondents are from larger institutions. In view of these limitations, the respondents’ perspectives may not represent the perspectives of all health care providers.
Surveying health care providers and device users is one of many tools the FDA uses to evaluate the public health impact of the potential problems associated with the use of medical devices. Typically, small sample surveys are used to collect qualitative information on postmarket experiences of clinicians or facilities with medical device performance or use. Survey respondents are selected based on their experience with the topic or device, their availability and their willingness to participate.
These findings are one piece of information and are not generalizable. No conclusions can be made about how a device functions in the broader clinical environment based on this report alone. Instead, the report should be considered along with other information that may include adverse event reports, scientific publications, clinical trials, enforcement/compliance information, and other data sources that are part of the FDA’s monitoring of device performance.
The FDA makes our scientific, medical, nursing, and engineering staff aware of the survey results as needed. If the FDA believes there is a significant risk of adverse events as noted from the survey, we will combine those results with data gained from other sources. The FDA will work with the manufacturers and health care provider organizations to make important information known to the clinical community. Additionally, the FDA continues to work with manufacturers to ensure the development, testing, and promulgation of methods for reducing the risk associated with these devices and to minimize the complications from adverse events that may occur in the course of normal usage. If the results of any survey raise serious concerns about the safety of these devices, the FDA may convene a group of clinical, scientific, and regulatory experts to discuss any necessary actions.
Food and Drug Administration,
Center for Devices and Radiological Health
Medical Product Safety Network (MedSun)
Small Sample Survey
Topic: The Effects of Severe Weather on Medical Devices
1. Did your hospital ever experience any loss of power, damage (as a result of severe weather) or need to rely on backup electrical power?
a. If yes, were any medical devices affected by any power outage, damage, or backup power reliance?
i. If yes, what type(s) of devices were they and how many were affected?
2. Did any medical devices malfunction during the severe weather?
a. If yes, which types of devices were affected?
b. Do you know what may have been the cause of the malfunction?
c. Were any of the devices that malfunctioned in use on a patient at the time?
i. If yes, was there patient injury or a delay in treatment?
3. During any of the storms, did lightning strikes or close thunder affect any medical devices?
a. If yes, can you describe what happened?
4. During any of the storms, did device alarms go off that were due to the severe weather?
a. If yes, what device(s) was it and what types of alarms sounded?
5. After the experiences you’ve had, has your hospital put any new or revised procedures in place to better handle any challenges with medical devices as a result of severe weather?
a. If yes, please describe.
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