October 27, 2005
Dear Health Care Practitioner:
This is to provide new information about a possible association between the Vapotherm® 2000i Respiratory Gas Administration device, which is used to add moisture and warm breathing gases through a nasal canula in patients receiving supplemental oxygen, and the occurrence of positive Ralstonia spp. cultures. The association was first reported in a MMWR article issued by the Centers for Disease Control and Prevention (CDC) on October 21, 2005. http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5441a5.htm
Please consider this new information in deciding whether and when to use the Vapotherm® device with your patients.
New information obtained by CDC from testing in a single hospital suggests that the newly developed chlorine dioxide disinfection protocol recommended by the manufacturer for disinfecting Vapotherm® devices and cartridges may not achieve sustained bacterial control in some instances. However, a similar experiment to test the efficacy of the chlorine dioxide protocol on a mixed population of heterotrophic bacteria, conducted by an internationally recognized authority on biofilms contracted by Vapotherm®, showed no growth of organisms immediately following and several days after chlorine dioxide treatment. These two tests of the chlorine dioxide disinfection protocol each involved only one machine and therefore the data must be interpreted with caution. However, the findings do suggest that under certain circumstances, this disinfection protocol might not achieve sustained microbial control. It should also be noted that some institutions had reported no growth of Ralstonia spp. in samples obtained from machines and cartridges that had been disinfected using the protocol that was formerly recommended by the firm.
Further evaluation of both the chlorine dioxide and peroxyacetic acid protocols currently recommended by Vapotherm® is ongoing. We do not have sufficient information at this time to know the effectiveness of the firm’s recommended peroxyacetic acid protocol.
Clinicians must continue to weigh the potential risks of Ralstonia spp. contamination of Vapotherm® devices against the benefits of using the device in patients requiring humidified oxygen therapy. In making a risk-benefit decision, bear in mind that immunocompromised patients are at particularly high risk for infection if exposed to a contaminated Vapotherm® device. Premature neonates and patients with underlying respiratory illness (such as cystic fibrosis) or malignancy may also be at risk for respiratory infection if exposed to breathing gases from contaminated devices. If a Vapotherm® device is used, patients should be monitored for signs and symptoms that may suggest infection. These may include, but are not limited to, changes in temperature, poor feeding, irritability, and changes in hematologic indices. Clinicians may want to consider Ralstonia spp. in the differential diagnoses even if it has not been isolated.
Additional Information about the Tests
The hospital test described above consisted of a single trial in which one Vapotherm® device and used filter cartridge, both known to be contaminated with Ralstonia spp., were subjected to the newly recommended chlorine dioxide disinfection protocol. The length of time that the machine and cartridge had been contaminated is unknown. Samples obtained immediately after disinfection grew no organisms. The machine was then allowed to run and the vapor condensate was collected in a sterile container. Samples of both the vapor condensate and the filter cartridge obtained after seven days of operation are growing Ralstonia spp. in culture.
In the experiment conducted for the firm by the independent authority, a laboratory-generated biofilm was grown in a device and cartridge for three weeks and then the machine and cartridge were subjected to the chlorine dioxide disinfection protocol. Results from this trial showed no growth immediately after disinfection or the in the following few days.
In the hospital test, it is not known if the presence of an unusually heavy biofilm in the machine and cartridge led to the failure to eradicate Ralstonia spp. In the company-sponsored test, the effect of testing a laboratory-generated, compared to a use-generated, biofilm is not known. These varying findings could suggest that the efficacy of the disinfection protocols may depend on the maturity of any biofilm contained within machines or cartridges.
Testing is being conducted to determine the source of Ralstonia spp. contamination and to further assess the efficacy of the new disinfection protocols. As more information from that testing becomes available, we will update this notification.
In August 2005, a Pennsylvania healthcare facility reported an increase in the incidence of Ralstonia spp. in cultures obtained from several patients using the Vapotherm® 2000i. Surveillance conducted by the CDC through pediatric and neonatology listservs identified additional institutions that have recovered Ralstonia spp. from clinical specimens and/or Vapotherm® machines. This information was published in the October 21, 2005 issue of a CDC MMWR (http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5441a5.htm). In response, Vapotherm® created new infection control procedures to reduce the risk of infectious disease transmission. As noted above, recent testing suggests that one of the newly recommended protocols may not be sufficient to eliminate this risk in some instances.
Reporting Cases of Ralstonia spp. associated with the Vapotherm® Respiratory Gas Administration Device or other medical devices
Clinicians are encouraged to report cases of Ralstonia spp. in patients using any Vapotherm® 2000 respiratory gas administration device. You should report cases directly to the device manufacturer, local or state health departments, or to the CDC at 1-800-893-0485. You should also report these cases and any other adverse events related to medical devices to MedWatch, the FDA’s voluntary reporting program. You may submit reports to MedWatch one of four ways: online; by telephone at 1-800-FDA-1088; by FAX at 1-800-FDA-0178; or by mail to MedWatch, Food and Drug Administration, 5600 Fishers Lane, Rockville, MD 20852-9787.
FDA medical device Public Health Notifications are available on the Internet. You can also be notified through email on the day the safety notification is released by subscribing to our list server. To subscribe, visit: http://service.govdelivery.com/service/subscribe.html?code=USFDACDRH_10.
Daniel G. Schultz, MD
Center for Devices and Radiological Health
Food and Drug Administration
* CDRH Preliminary Public Health Notifications are intended to quickly share device-related safety information with healthcare providers when the available information and our understanding of an issue are still evolving. We will revise them as new information merits and so encourage you to check this site for updates.