HELP! Minvent Alarm keeps going off

I have had my Respironics bipap autoSV for a little over a year now. It's been great, no problems. But recently, the Alarm + Minvent keeps coming on and I'm not sure why. Is my understanding correct that the Minvent is the amount of air you are receiving.

I've tried resetting the alarm per the owners manual and it keeps triggering. I've changed filters, hoses, masks, humidifier, no humidifier, and the valve with the little flap where the air comes out of the machine.

Please help. I have not had my machine for the last two nights and I feel AWFUL!!

Thanks.

bump -- ideas anyone?

According to the the user manual this is a high priority alarm which means that "A low minute ventilation event occurred during therapy".

The instructions on what to do if this alarm sounds are "Press the RESET button to reset the alarm. Continue using the device. Report the alarm to your health care professional."


What did your health care professional say?

HI, i will look at our clinic manual.. but if the alarm just started recently and nothing else has changed it may be machine issues. The minute volume is your breath rate multiplied by your tidal volume to get your average volume over a minute. You can disable the alarm but i would have your rt or md check it out before doing anything rash... .good luck i will try to get back to you.. steve from canada...

The questions raised here prompted me to do a little research. This information is abstracted from several Wikipedia articles and other technical articles found using Google.

Minvent (minute ventalation) is the total amount of air exchanged by the lungs during a one minute period. The tidal air volume is the amount of air exchanged by the lungs in a normal breath. I suspect the minvent value is calculated by sv machines which track the number of breaths per minute and the tidal air volume.

i.e. Minvent = breaths per minute X tidal air volume

Tidal air is a function of chest dimentions. Men, being generally physically bigger than women, have larger tidal volumes. Breaths per minute vary, going up with excercise and excitement and down with rest and relaxation.

Some of the "normal" ranges for these measurements reported in the articles are:

resting breaths per min = 12 to 20
resting minvent = 5 to 10 liters per minute
tidal air (for men) = approx 500 ml per minute = 0.5 liters per minute
tidal air (for womwn) = approx 350 mi per minute = 0.35 liters per minute.

So if alarms are going off there are several posibilities. 1) low or zero breaths per minute; 2) very shallow breathing; 3) machine malfunctions. Also, the point at which the alarm should trigger suggested by these reports is probably just below 5 liters per minute. Here I make my disclaimer that I am not a doctor or a technician so please DO NOT rely upon my analysis to alter your machine settings.

I use a Respironics bipap autoSV advanced with the Encore Pro Smart Card. I also have the Encore Pro 2.2 software to read the smart card. My machine reports my average breaths per minute for the past week = 17.1 and the average minvent = 8.9 liters per minute. Working backwards, my calculated tidal air volume is appro. 520 ml.

i.e. 520ml = 8900ml divided by 17.1 breaths per minute

I hope this analysis helps.

Must admit I had alarms going off constantly the 1st 2 nights I used my Bipap Auto SV back in 2008. The alarms were worse than the effect so I disabled them & then started getting good nights sleep.

The alarms are really for use in a monitored environment (small hospital, nursing home, etc: ). They are of questionable use in the home environment because they can do more harm to sleep than any good.

DSM

re minivent alarm, go to setup then schroll to minivent and set at 0.0. No more alarms. Worked for me.