Medical Device Essential to Lung and Heart Surgery Linked to Deadly Bacterial Infection

patients are often the last to know - if they are ever notified at all

Medical Device Essential to Lung and Heart Surgery Linked to Deadly Bacterial Infection
Image: Pexels
October 14, 2016

Hospitals across the U.S. have reported incidents in which bacteria causing deadly infections have been linked to a medical device that regulates a patient's body temperature during certain heart and lung operations.

The Bacterial Infection

The non-tuberculosis mycobacteria (NTM) microbe is common in the environment and usually does not cause harm. However, when it enters the chest cavity or contaminates a surgical patient's prosthetic heart valve, it can cause a fatal infection.

Officials at Greenville Medical Center in South Carolina confirmed in 2014 that 15 patients had been diagnosed with the same rare infection caused by these bacteria. Four of the 15 died.

The bacteria was traced by the hospital and the South Carolina Public Health Department back to the heater-cooler devices (HCDs) used by the hospital. HCDs are machines that regulate patient body temperature during certain heart and lung operations. The investigators did not say that the HCDs were responsible for the infections, partly because the bacteria grow in water and was also discovered in several other locations throughout the hospital. However, the victims' attorneys think that there is a clear link.

"Yes, the bacteria is a common environmental contaminant," says Blake Smith, the lawyer who settled a wrongful death suit filed by the widow of a man who died from such an infection against Greenville Memorial Hospital in 2015. "But only the heater-cooler device is capable of aerosolizing that bacteria and spraying it directly into the chest cavity during surgery."

There have been similar cases public reported at hospitals in other states, including Iowa and Pennsylvania. There are some hospitals and federal agencies—as well as at least one device manufacturer—that have acknowledge that HCDs can hold the deadly microbes and then spray them through their exhaust vents across the operating room.

The Food and Drug Administration (FDA) received 180 incident reports between January 1, 2010 and February 29, 2016 regarding HCDs around the world. Included among these are 16 U.S. hospitals spanning 10 states in which no fewer than 45 patients were infected and at least nine died.

Most of these kinds of incidents have been linked to the Sorin Stockert 3T Heating-Cooling System device, which is manufactured by European company LivaNova.

The FDA database, however, names neither the hospitals where these incidents have taken place, nor the states in which the hospitals are located. In addition, there is no clear way to figure out how well any given institution investigated the issue or what steps—if any—it took to either inform patients or prevent future exposure.

In the fall of 2015, both the Centers for Disease Control and Prevention (CDC) and the FDA issued advisories that urged facilities providing healthcare to take action to lessen the risk of such infections and to monitor patients who have undergone valve replacement or heart bypass surgery for the infections. It is expected that the CDC will issue another advisory this week.

Thus far, however, the agencies have not advised healthcare facilities to notify all surgical patients about the possible risk posted to them by HCDs. As a result, critics say, too many patients are still being put in danger.

The regulation of a patient's body temperature during surgery is what makes HCDs essential to heart and lung operations meant to extend life. Thousands of operating rooms across the U.S. have them. They are used in hundreds of thousands of surgeries annually, including surgeries such as heart bypass, valve replacement, and other heart and lung operations.

HCDs have the appearance of freestanding portable air conditioners. They contain tanks of water that circulate through narrow tubes in the machine. They have been believed to be safe because the water in those circuits does not directly contact the patient. However, the FDA now says that it can leak into other parts of the machine and take bacteria along with it. If the bacteria get to the HCD's exhaust fan, it can be sprayed through the air.

"Cases out there that are going undiagnosed"

The numbers currently suggest that there is small risk of a particular HCD being contaminated or infecting a patient. However, it is uniquely hard to quantify this risk, and many experts have stated that confirmed cases probably represent only a fraction of the actual infections.

"We know there are cases out there that are going undiagnosed," said Michael Edmond, M.D., an epidemiologist at the University of Iowa Hospitals and Clinics in Iowa City.

One part of the issue is that these infections are difficult to diagnose. Some of the bacteria's strains grow at such a slow rate that it can take as many as six years for symptoms to show, and doctors rarely test for the infection because it occurs so rarely.

"The lag time really adds to the challenge," Edmond said. "If you develop flu-like symptoms a few years after you have an operation, a doctor isn't likely to link the two."

And in spite of numerous federal advisories issued to hospitals, many doctors remain unaware of the risk.

"If you query most heart surgeons around the country, they would quite honestly have an ignorance of this problem," said Keith Allen, M.D., a cardiothoracic surgeon based in Kansas City, Missouri.

Numerous NTM-infection outbreaks have been tentatively linked to the devices over the past year and a half. Two hospitals in Pennsylvania have publicly reported outbreaks that may be linked to their HCDs; at least 14 likely incidences have been identified. And in Iowa, two hospitals reported three such infections.

At the University of Washington Medical Center in Washington, five patients fell ill and two died after they were infected with legionella, another type of bacteria. Legionella is like NTM in that it occurs commonly in nature but is rare and potentially deadly in hospitals. The Washington hospital acknowledged that it had found that its HCDs were contaminated with legionella but, like Greenville Medical, did not quite state that the devices were responsible for the infections or deaths.

In at least some of the cases that occurred in Pennsylvania and Iowa, it was discovered that the HCDs in question were contaminated with the same bacteria that surgical patients had been infected with who had been exposed to them during their operations.

The FDA calls the link between the HCDs and possibly deadly bacteria a "serious public health concern."

However, though cases are continuing to emerge, hospitals are still not warning patients either before surgery or after. According to Lawrence Muscarella, Ph.D., an expert on medical devices who consults with both hospitals and manufacturers on safety matters, there is a significant gap between how many cases are reported to the FDA and how many are being acknowledged publicly.

In examining the FDA's database of medical-device incident reports for possible clusters of infections, Muscarella has so far found at least one: an unnamed hospital located likely either in or near Philadelphia that confirmed four infections with NTM in heart and lung surgery patients. Two of those patients died. It is not clear whether that hospital—or any of the other unnamed institutions that have thus far reported contamination of their devices—has either notified at-risk patients or begun to monitor them for symptoms of NTM infection.

"The panel does not recommend notifying all patients"

The FDA held a two-day meeting in early June so that experts could discuss the HCD problem and determine recommendations for monitoring outbreaks and tracking patients.

One key matter at issue was when—if at all—patients who were exposed to the devices should be warned about the risks. Several members of the panel argued against wide-ranging patient notification. Richard Hopkins, M.D., a cardiac surgeon at Children's Mercy Academic Medical Center in Kansas City, Missouri, said, "I'm a little loathe to make a recommendation that's going to cost a hospital $1.5 million based on one case." Other panel members argued that it would incite needless panic to alert every patient who underwent a surgery using an HCD.

Not every member agreed with that assessment. Jonathan Zenilman, M.D., chief of Johns Hopkins Bayview Medical Center's Division of Infectious Diseases, suggested that just "one case" of infection with NTM could qualify as an outbreak and therefore could trigger a wide-ranging alert. In addition, Laurence Givner, M.D., a pediatric infectious disease specialist at Wake Forest University, stated that every patient who has surgery with one of these devices ought to be warned about the risk.

In the end, the panel recommended that healthcare providers be informed first and that notifications of patients should be limited in range. "If a facility discovers one patient infection, the panel does not recommend notifying all patients," states the meeting summary. The panel was "more receptive" of the possibility of notifying patients after the occurrence of two infections; however, it also suggested that if the facility could figure out exactly which patients had had surgery in an operating room containing a contaminated HCD, than just those particular patients should be informed.

Lisa McGiffert, the director of Consumer Report's Safe Patient Project, believes that this recommendation is insufficient and that hospitals have not yet taken as much responsibility for the problem as they should.

"More should be done to protect patients and inform them of the risk of infection months and even years after exposure," she said. "Without that notice, patients don't know what symptoms to watch out for and can't be promptly treated with antibiotics, making recovery less likely. They have a right to know. We believe that every hospital using these devices should inform all patients who have surgery with these devices about this risk of infection."

Taking Action

Some hospitals have taken aggressive action in response to the outbreak. One such facility is the University of Iowa Medical Center, which discovered NTM in a patient in January who had undergone cardiac bypass surgery. In days, the hospital put together an emergency response team comprising experts from every relevant department, including infection control, lab testing, surgery, and cardiology.

Within two weeks, that team sent samples out for testing from all HCDs in the hospital. It also figured out and implemented a "workaround" involving the drilling of holes through the walls of the operating rooms to keep the devices away from patients but still use them during operations. "It was a busy couple of weeks," said Daniel Diekema, M.D., who directs the hospital's division of infectious diseases.

The hospital was just as thorough about informing patients. Using billing codes and surgical logs, it put together a list of every patient who had been exposed to an HCD that stretched back five years to account for the long lag time of some NTM infections. The hospital discovered 1,500 patients and chose to notify all of them, said Edmond. "We even notified the patients where the device wasn't used but was running on standby during their surgery," he stated.

In addition, the team also made an instant alert in its electronic medical record system that is triggered for any patient who underwent bypass surgery and also experienced any NTM symptoms, including fever, severe pain at the site of the surgery, and inflammation of the heart or other organs. It explains how and why the provider ought to order tests for NTM, as well as an infectious disease consult.

The steps taken by the University of Iowa Medical Center go above and beyond the recommendations issued to date by the CDC and the FDA—namely that hospitals should adhere to strict protocols for cleaning HDCs, that they direct the exhaust fan in the device away from the operating table, and that they check for NTM cases in lab records if any device tests positive for bacterial contamination.

Edmond, who works at the University of Iowa Hospital, believes that these current federal guidelines are insufficient protection for patients.

"You're not going to find many NTM cases by just passively looking back through lab records," he said. "Because the infection tends to be overlooked or misdiagnosed, you have to be more proactive than that."

Cluing Patients In

Edmond believes that relocate the devices outside the operating rooms is the most important step a hospital can take. "I can't believe no one's stepped up and demanded that yet," he said.

However, the CDC claims that it is not possible to implement that plan everywhere. "Not all ORs will be able to do that," said Michael Bell, M.D., deputy director of the CDC's Division of Healthcare Quality Promotion.

In addition, neither the FDA nor the CDC is authorized to compel hospitals to inform patients. "Those powers live at the state level," he says. "So any mandate really has to come from individual hospitals working with state health departments."