BEUDAMED
    FDA Adverse Event Injury Summary report: N

    VAPOTHERM

    MDR report key: 585545 · Received March 23, 2005

    Report

    Report Number
    MW1035006
    Event Type
    Injury
    Date Received
    March 23, 2005
    Date of Event
    February 26, 2005
    Report Date
    March 23, 2005
    Manufacturer
    VAPOTHERM, INC.
    Product Code
    BTT
    Adverse Event
    Yes
    Report Source
    Voluntary report
    Reporter Location
    MO, US
    Reporter Occupation
    RISK MANAGER

    Narratives

    Description of Event or Problem · 1

    ADD'L INFO REC'D FROM RPTR 4/28/05: THE PT IN QUESTION WAS ADMITTED WITH RSV AND HYPONATRAEMIA. ADMISSION SODIUM LEVEL WAS 128 MMOL/L [NORMAL 135-145]. PRIOR TO THE SEIZURE AND HYPONATRAEMIA REPORTED IN THIS CASE THE PT WAS REPORTED TO HAVE NASAL FLARING, RETRACTIONS, BILATERAL COURSE BREATH SOUNDS, CONGESTION AND COUGHING. THESE SYMPTOMS HAVE BEEN ASSOCIATED WITH RSV AND RESPIRATORY INSUFFICIENCY. TYPICALLY, HYPONATREMIC PTS ARE TREATED WITH IV THERAPY TO RESTORE NORMAL SODIUM LEVELS. THIS PT WAS TRANSFERRED FROM PICU TO THE FLOOR WITHOUT IV THERAPY FOLLOWING DISCONTINUATION OF MECHANICAL VENTILATION. FOLLOWING MECHANICAL VENTILATION THE PT WAS PLACED ON SUPPLEMENTAL OXYGEN THERAPY FROM 3-6 LPM VIA VAPOTHERM. PRIOR TO THE EPISODE ALL IV HAD BEEN DISCONTINUED DESPITE CONTINUED RESPIRATORY SYMPTOMS AND NO LAB RESULTS ARE AVAILABLE FOR SODIUM LEVELS. NEAR THE POINT OF THE SEIZURE THE PT'S OXYGEN SATURATION BY PULSE OXIMETER WAS 69%. FOLLOWING THE SEIZURE THE PT WAS RETURNED TO THE PICU WHERE IV THERAPY WAS STARTED AND SODIUM LEVEL RETURNED TO NORMAL. HOWEVER, THE PT CONTINUED TO REQUIRE RESPIRATORY SUPPORT, INITIALLY WITH SUPPLEMENTAL OXYGEN VIA THE VAPOTHERM AND LATER BY CPAP AND FINALLY INTUBATION AND A RETURN TO MECHANICAL VENTILATION. DISCUSSION: THIRTY-THREE PERCENT OF PTS WITH RSV HAVE BEEN REPORTED TO DEVELOP HYPONATRAEMIA AND OF THOSE PTS 4% DEVELOP SEIZURE DUE TO HYPONATRAEMIA. 1 THE HYPOXEMIA, IN ASSOCIATION WITH THE UNRESOLVED RSV AND RESPIRATORY INSUFFICIENCY, ARE MAJOR RISK FACTORS FOR HYPONATREMIA. 2 THE PT'S RECORD INDICATES UNSPECIFIC MENINGITIS. IN ACUTE MENINGITIS HYPONATREMIA IS COMMON AND TRADITIONALLY ATTRIBUTED TO INAPPROPRIATE WATER RETENTION. 3 IN A RECENT STUDY IT WAS DETERMINE THAT HYPONATREMIA IN ACUTE MENINGITIS IS NOT EXCLUSIVELY BROUGHT ABOUT BY INAPPROPRIATE WATER RETENTION. 3 THIS APPEARS THE MATCH THIS PT'S PRESENTATION. HYPONATREMIA IS A FREQUENT FINDING IN SEIZURES RESULTING FROM MENINGITIS. 4 THE SEVERITY AND COMPLEXITY OF THIS PT'S ILLNESS INCREASED THEIR RISK FOR SEIZURE. HUMIDIFICATION OF THE BREATHING GAS IS ACCOMPLISHED BY VAPOTHERM WITH A RELATIVE HUMIDITY AROUND 99%. 5 THERE ARE NO CONTRAINDICATIONS FOR BREATHING MEDICAL GAS THAT HAS BEEN HUMIDIFIED. MOLECULAR PHASE MOISTURE AT NEAR BODY TEMPERATURE AND AT EQUAL SATURATION WITH GAS IN THE BODY DOES NOT CREATE A WATER GAIN. SUCH INSPIRED GAS IN SIMILAR TO BREATHING AIR THAT IS AT 95% RELATIVE HUMIDITY AND TEMPERATURE OF 97 DEGREE F THAT IS COMMON IS THE SUMMER IN THE SOUTHEASTERN UNITED STATES. THE LUNGS CONTAIN VAPOR-SATURATED GAS AT ALL TIMES, AND ARE NOT AFFECTED BY THE HUMIDITY OF INSPIRED GAS. BREATHING MEDICAL GAS UNDER THESE CONDITIONS IS THE BEST METHOD FOR BREATHING MEDICAL GAS BECAUSE IT DOES NOT PUT THE PT AT RISK. 6 AEROSOLIZED WATER AND INSTILLED WATER MAY BE HAZARDOUS BECAUSE OF THEIR DEMONSTRATED POTENTIAL FOR DELIVERING EXCESSIVE WATER TO THE AIRWAY. WATER VAPOR, AS PROVIDED BY THE VAPOTHERM'S VAPOR TRANSFER SYSTEM, IS THE BEST FORM OF HUMIDIFICATION BECAUSE IT IS UNLIKELY TO DELIVER SUFFICIENT WATER TO CAUSE PULMONARY INJURY. 6 RAINOUT OF WATER IN THE PT AIRWAY IS NOT A POSSIBILITY WITH THE VAPOTHERM BECAUSE THE HUMIDIFICATION IS DELIVERED AT BODY TEMPERATURE. THEREFORE, NO THERAML GRADIENT EXISTS THAT CAN CAUSE RAINOUT. THE WATER DELIVERED BY THE VAPOTHERM IS IN A GASEOUS STATE OR MOLECULAR WATER IN THE GAS. THE ABSOLUTE HUMIDITY IN THIS CASE IS EQUAL TO THAT AT THE CARINI. THE WATER VAPOR CONTENT OF THE LUNG AND THE VAPOTHERM IS 44 MG/L. THERE IS NO GAIN OF WATER TO THE PT UNDER THESE CONDITIONS OF EQUILIBRIUM. THE ABSENCE OF WATER GAIN IS DOCUMENTED BY THE LACK OF WEIGHT GAIN IN THIS PT. THIS IS IN CONTRAST TO THE USE OF AEROSOL THERAPY, WHERE SUBSTANTIAL QUANTITIES OF WATER MAY BE DEPOSITED BY IMPACT OF LIQUID DROPLETS IN THE PT AIRWAY. VAPOTHERM DEVICES CREATE ONLY WATER VAPOR AND DO NOT PRODUCE AEROSOLS. FINALLY, THE QUANTITY OF WATER, IN THE WATER BAG CONNECTED TO THE VAPOTHERM, CONVERTED TO VAPOR, IN THIS CASE, WAS ABOUT 316 MLS PER 24-HOUR PERIOD. THIS QUANTITY, 10.6 OUNCES OF WATER, EVEN AS FLUID, OVER A 24-HOUR PERIOD WILL NOT LEAD TO WATER INTOXICATION WITHOUT SECONDARY COMPLICATIONS SUCH AS RENAL FAILURE AND ADDITIONAL FLUID INGESTION. THERE WAS NO MEASURABLE WEIGHT GAIN IN THIS PT TO SUGGEST POSITIVE WATER BALANCE. TWO STAFF MEMBERS AT TH HOSP DISCUSSED THE INCIDENT AT THE TIME WITH VAPOTHERM, AND ON BOTH OCCASIONS IT WAS POINTED OUT THAT IT IS IMPOSSIBLE TO WATER-LOAD A PT BY BREATHING VAPOR-SATURATED GASES AT BODY TEMPERATURE. THE EFFECT ON WATER BALANCE IS TO REDUCE OR ELIMINATE EVAPORATIVE WATER LOSS FROM THE EPITHELIUM OF THE UPPER AIRWAY, BUT NOT TO TRANSFER WATER TO THE AIRWAY. CONCLUSION: WHILE THE SOURCE OF THE "EXCESSIVE WATER" CANNOT BE DETERMINED FROM THE INFO PRESENTED IN THE MDR, VAPOTHERM IS CONFIDENT THAT IT DID NOT RESULT FROM SUPPLEMENTAL OXYGEN HUMIDIFIED BY MOLECULAR WATER VAPOR.

    Description of Event or Problem · 1

    PT DEVELOPED SEIZURE AND HYPONATREMIA (SODIUM 109) WHILE ON VAPOTHERM. THERE IS NO PROVEN CAUSE OF THE ACUTE WATER INTOXICATION. IT IS SUSPECTED THERE MAY HAVE BEEN EXCESSIVE WATER SWALLOWED BY THE PT AND THIS CAUSED THE PROBLEM.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    1 VAPOTHERM HUMIDIFIER BTT VAPOTHERM, INC. UNK *

    Patients

    Seq Age Sex Outcome Treatment
    1 1 MO Hospitalization| L| R