Machine (semi)Failure

[Bertelman]

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10 m/o with "new Dx heart murmur" for cardiac MRI. Otherwise healthy, term delivery. Mask induction -> IV -> vec -> tube. Transport to magnet, hookup to schmancy new Drager Fabius MRI machine that has been used at least twice since installation successfully. Set the vent, fiddle with monitors, kid slides into the magnet, everything looks OK.

Then the screen on the vent goes out. Black. Nada. Scan hasn't started yet, staff is still present. You scan the machine, bellows is still rising, all other components appear to have power. Chest is still rising. ETCO2 is present. VSS.

What do you do?

 

[urge]

What kind of hospital starts their work up for murmur in a "healthy" kid with an MRI? No echo machines there?

Fabius machine is pretty good. I'm sure no body will have a hard time identifying the safest answer. Can you get away with a busted machine? Maybe.

 

[Planktonmd]

Patient is stable, you said VS are stable so you must still have a functioning monitor, you also said that you have + ETCO2 and you can see the ventiltaor moving, what else do you need?
Finish the case and then figure out what happened to screen.

 

[Bertelman]

What kind of hospital starts their work up for murmur in a "healthy" kid with an MRI? No echo machines there?

I can't honestly say at what time point in the workup of this murmur the MRI occurred. May have been an echo report, if so it was of little value for us, i.e. didn't reveal any major anomaly.

Patient is stable, you said VS are stable so you must still have a functioning monitor, you also said that you have + ETCO2 and you can see the ventiltaor moving, what else do you need?
Finish the case and then figure out what happened to screen.

So someone had the bright idea of shutting the vent off and restarting, in the hopes of getting the screen back. Now the vent is back on, screen is still out, you put it on volume control and it starts delivering a standard TV that is WAY too big for the kiddo.

You'll be in there with the donut for 60-90 min., intermittently breath-holding for the scans.

 

[Pilot Doc]

So one of my favorite thought experiments in situations like this is to ask myself

"Dr. Pilot Doc, please explain to the jury why you chose to XXXX on the evening of March 18, 2009."


Generally, I get an immediate visceral response that what I'm doing is easily justifiable or it's not.


In this case, there is no urgency at all. You would have a very hard time defending even the slightest morbidity. Take the kid out, wake him up.

If you stay with him and manually bag him, I think that's an acceptable response as well. But the vent has to go.

 

[Jeff05]

wake kid up.
i would not use unreliable equipment in a peds case.

 

[pgg]

In this case, there is no urgency at all. You would have a very hard time defending even the slightest morbidity. Take the kid out, wake him up.

If you stay with him and manually bag him, I think that's an acceptable response as well. But the vent has to go.

I think manually ventilating him is the right thing to do.

The $million question is whether or not the screen failure implies other malfunctions. The risks of continuing to use the vent are hypoventilation, hyperventilation, a hypoxic mixture, unknown volatile agent levels, and/or inappropriate airway pressures. Here we have quantitative ETCO2 (presumably a gas analyzer too for the volatile and O2) and a perfectly reliable analog pressure gauge in the circuit. It's probably safe to continue using the vent provided you keep an eye on those monitors.

Although to play devil's advocate, for all we know some important bit of the machine is cooked and the next thing the vent might do is deliver a 4000 cc tidal volume and pop a lung ... lotta good intermittently watching the pressure gauge did there.

I can't really justify trusting a malfunctioning machine, when it'd be so easy to turn off the vent, and bag him for the case.

But I don't think aborting the MRI and waking the kid up is necessary.

 

[Licoricestick]

Option A: abort + wake the kid up. In doing this you can stop using your ventilator, but you're still dependent on your monitors and probably still using your circuit, vaporiser etc so you HAVEN'T removed equipment from the equation. You also have a paralysed kid (what dose of Vec was given? how long between vec and stuffed vent screen? what twitches do you have?) so if you really want to avoid all your equipment you need to convert to direct bagging on the tube with supplemental O2 and IV sedation until you can reverse and then wake him up and pull the tube. [Alternatively you could try sugammadex but I have a feeling it would be an off label use and it's certainly a drug I'm unfamiliar with - so it wouldn't be my preferred choice in this scenario]
So after all that, you then have to find another anaesthetic supported MRI slot and give him another GA. Don't know how easy it is to come by cMRI slots with available anaesthetic support but at the paeds hospital in my town.... that's at least weeks, if not a couple of months to wait (and someone thought this murmur was worth subjecting the child to a GA and cMRI to investigate). So this approach is not as simple as "safest option is to wake him up"

Option B: continue using the machine, working off the assumption that although you can't see some of the information the ventilator would tell you, you have other infomation to infer from and everything is still going OK.
My problem with this of course is the "So doctor, why did you....." as mentioned earlier. Wathcing chest rise and fall, seeing a pink kid, seeing good sats, good ETCO2 and ETCO2 trace and watching a pressure gauge are definitely all useful things, but if something isn't as it should be on the ventilator settings these things are all going to tell you after the fact.

Option C: shut of the vent and put those hands to work bagging; continue to use your gases, circut, volatile agent, monitors. Make yourself comfortable, get your (friendly I hope) MRI tech to bring you a pair of earplugs and make sure you know how they will communicate when they need the breath holds...and settle in for a bag-a-thon. This would be my preferred option, as I think it is probably the safest of the three options and still gets the investigation done.

Theoretically there could be an option D- get a new machine. But how many hospitals have spare machines that are serviced, have had the appropriate daily pre use check performed, are certified MRI compatible and can be delivered to the MRI unit (which I assume is separate from other anaesthetising locations) with an appropriate speed????? Definitely not mine!

 

[jwk]

Option C: shut of the vent and put those hands to work bagging; continue to use your gases, circut, volatile agent, monitors. Make yourself comfortable, get your (friendly I hope) MRI tech to bring you a pair of earplugs and make sure you know how they will communicate when they need the breath holds...and settle in for a bag-a-thon. This would be my preferred option, as I think it is probably the safest of the three options and still gets the investigation done.

Theoretically there could be an option D- get a new machine. But how many hospitals have spare machines that are serviced, have had the appropriate daily pre use check performed, are certified MRI compatible and can be delivered to the MRI unit (which I assume is separate from other anaesthetising locations) with an appropriate speed????? Definitely not mine!

Ah, good old hand-bagging - like we used to do all the time in the old days. Perfectly safe but definitely makes the youngsters pucker a little. 😀

And to the OP - "schmancy new Drager Fabius MRI machine that has been used at least twice since installation successfully" . Wow - that's a confidence builder. Tell me - did you or anyone with you do a full machine check prior to this case? I mean really do a check, not just a leak check and see if there was an O2 tank hanging on the back. A machine that sits around for weeks between cases is an accident waiting to happen, although admittedly electronics failure is more on the unusual side. Particularly in remote locations, you should have backup equipment with you, including ambu bag, chemical EtCO2 indicator, etc.

 

[urge]

I can't honestly say at what time point in the workup of this murmur the MRI occurred. May have been an echo report, if so it was of little value for us, i.e. didn't reveal any major anomaly.

"There is something in the jelly". I'm sure that wasn't a normal "healthy" kid.

Do you guys tube every kid in the MRI? No spontaneously breathing LMAs?

 

[urge]

And to the OP - "schmancy new Drager Fabius MRI machine that has been used at least twice since installation successfully" .

Those machines check themselves and keep a log. Very easy to check if the damn bastard in the room bothered to click the "check machine" button in the morning. You would be surprised at how many people still don't check.

 

[Jeff05]

sugammadex is NOT on the market. also it's not for vecuronium. it's made to bind roc.

 

[Planktonmd]

sugammadex is NOT on the market. also it's not for vecuronium. it's made to bind roc.

Actually, Sugammadex works for Rocuronium, Vecuronium and to a lesser degree Pancuronium.
Look it up.

 

[jwk]

sugammadex is NOT on the market. also it's not for vecuronium. it's made to bind roc.

Licorice appears to be from that island continent so he's probably lucky enough to have it there. And sugammadex will work on other non-depolarizers, but apparently is best with roc.

 

[huktonfonix]

"There is something in the jelly". I'm sure that wasn't a normal "healthy" kid.

Do you guys tube every kid in the MRI? No spontaneously breathing LMAs?

Probably done for the breath holding parts. Of course, you could do it with an LMA and hyperventilation also.

 

[Dimoak]

Bert, was the screen completely black or was it just drawing weird artifacts or a "signal not found" screen, etc.? If everything was working, but screen appeared to not be turning on, there's a chance it may have just been the screen's power that wasn't working, otherwise there's a decent chance that at least something would be up there. If your DFMRI model has an external monitor port, perhaps you could have gotten hospital IT to bring up another screen to see if that works.

 

[Bertelman]

The $million question is whether or not the screen failure implies other malfunctions. The risks of continuing to use the vent are hypoventilation, hyperventilation, a hypoxic mixture, unknown volatile agent levels, and/or inappropriate airway pressures. Here we have quantitative ETCO2 (presumably a gas analyzer too for the volatile and O2) and a perfectly reliable analog pressure gauge in the circuit. It's probably safe to continue using the vent provided you keep an eye on those monitors.

Although to play devil's advocate, for all we know some important bit of the machine is cooked and the next thing the vent might do is deliver a 4000 cc tidal volume and pop a lung ... lotta good intermittently watching the pressure gauge did there.

Here's the monitors I had: BP, ECG, SpO2, ETCO2, and of course the pressure gauge. All indication suggested the screen was the ONLY malfunction. Obvious alarms were still intact, eg apnea/low VE. All other lights were functioning appropriately.

what dose of Vec was given? how long between vec and stuffed vent screen? what twitches do you have?)

Intubating dose of Vec-.1/kg. Screen crapped out <30 min later. Not that I would have been measuring twitches, because he was going to be deep in the tube.

And to the OP - "schmancy new Drager Fabius MRI machine that has been used at least twice since installation successfully" . Wow - that's a confidence builder. Tell me - did you or anyone with you do a full machine check prior to this case? I mean really do a check, not just a leak check and see if there was an O2 tank hanging on the back. A machine that sits around for weeks between cases is an accident waiting to happen, although admittedly electronics failure is more on the unusual side. Particularly in remote locations, you should have backup equipment with you, including ambu bag, chemical EtCO2 indicator, etc.

I said the machine was new. I mean brand f-ing new. Was installed 8 days prior, with at least two successful GA's since then. Not exactly sitting around in a closet collecting dust. And yes, I did the full check. Unfortunately, there's not a test for "screen that is about to crap out w/o warning"

"There is something in the jelly". I'm sure that wasn't a normal "healthy" kid.

"Otherwise healthy" as in a 10 m/o with a heart murmur and no other significant medical problems. I didn't say he was healthy, and I don't think any child with a new heart murmur is by default "sick"

Probably done for the breath holding parts. Of course, you could do it with an LMA and hyperventilation also.

Our standard for Pedi MRI is prop drip with cannula v. LMA. We only tube the cardiac cases for the breath hold.

Bert, was the screen completely black or was it just drawing weird artifacts or a "signal not found" screen, etc.? If everything was working, but screen appeared to not be turning on, there's a chance it may have just been the screen's power that wasn't working, otherwise there's a decent chance that at least something would be up there. If your DFMRI model has an external monitor port, perhaps you could have gotten hospital IT to bring up another screen to see if that works.

Screen was completely black. I'll check on the external monitor port. That's a good idea, though I don't imagine this will happen again.

 

[Bertelman]

Theoretically there could be an option D- get a new machine. But how many hospitals have spare machines that are serviced, have had the appropriate daily pre use check performed, are certified MRI compatible and can be delivered to the MRI unit (which I assume is separate from other anaesthetising locations) with an appropriate speed????? Definitely not mine!

This was actually an option, though I didn't find out until later. Our old machine was still in house, but we were told initially it had left.

 

[Bertelman]

Option C: shut of the vent and put those hands to work bagging; continue to use your gases, circut, volatile agent, monitors. Make yourself comfortable, get your (friendly I hope) MRI tech to bring you a pair of earplugs and make sure you know how they will communicate when they need the breath holds...and settle in for a bag-a-thon. This would be my preferred option, as I think it is probably the safest of the three options and still gets the investigation done.

This was my final answer. When the attending wanted to cancel, I suggested the above. I was going to be in the room for the duration either way, as I had to provide the apneic periods. We knew we still had gas flow, agent, could monitor pressure, ETCO2 and standard monitors. Our monitor setup does not include ET agent, and of course I lost FiO2 on the Fabius.

Settled in for an hour or two of hand bagging a rate of 25-30 with a pressure gauge and chest rise. Charted during the 30 sec. apneic periods. Convinced myself this was old skool, and a nice lesson at that. Got bored thirty minutes later. Don't know how you old dudes used to bag-mask. I didn't even want to dedicate one hand.

Tried to refresh my memory of the button arrangement for setting the vent, which at this point wanted to deliver VT 600 and rate 12. Broke out the manual, showed absolute low values for each, so I individually dialed in to the lowest settings for each, then worked up until I was delivering approximately appropriate values for VT and RR, and set the pressure limit as well. Confirmed rate with the ETCO2, VT roughly with the bellows.

Was a bit dicey at first, but then became comfortable. Switched from manual to VC back and forth for the apnea, finished the case.

 

[jwk]

This was my final answer. When the attending wanted to cancel, I suggested the above. I was going to be in the room for the duration either way, as I had to provide the apneic periods. We knew we still had gas flow, agent, could monitor pressure, ETCO2 and standard monitors. Our monitor setup does not include ET agent, and of course I lost FiO2 on the Fabius.

Settled in for an hour or two of hand bagging a rate of 25-30 with a pressure gauge and chest rise. Charted during the 30 sec. apneic periods. Convinced myself this was old skool, and a nice lesson at that. Got bored thirty minutes later. Don't know how you old dudes used to bag-mask. I didn't even want to dedicate one hand.

Tried to refresh my memory of the button arrangement for setting the vent, which at this point wanted to deliver VT 600 and rate 12. Broke out the manual, showed absolute low values for each, so I individually dialed in to the lowest settings for each, then worked up until I was delivering approximately appropriate values for VT and RR, and set the pressure limit as well. Confirmed rate with the ETCO2, VT roughly with the bellows.

Was a bit dicey at first, but then became comfortable. Switched from manual to VC back and forth for the apnea, finished the case.

IC, so you just lost the vent and display for it, but still had the important stuff. (gas monitoring is a luxury many places still don't have)

Don't you think this built your character tremendously? 😉 That's what we were told when we did 3-hr mask cases as students in the copper kettle pre-LMA days.

 

[proman]

Do you routinely use volume control in kids? I never do, especially in a 10mo. Pressure control only. What do others use?

 

[Arch Guillotti]

Do you routinely use volume control in kids? I never do, especially in a 10mo. Pressure control only. What do others use?

pressure only, never volume

 

[pgg]

Licorice appears to be from that island continent so he's probably lucky enough to have it there. And sugammadex will work on other non-depolarizers, but apparently is best with roc.

It will work on other steroid nondepolarizers, but not the benzylisoquinoliniums like atracurium, cis-atracurium, mivacurium (not that anyone can buy it any more), doxacurium (not that anyone has it) ...

Not that it matters since the FDA shot it down.

Do you routinely use volume control in kids? I never do, especially in a 10mo. Pressure control only. What do others use?

I always use volume control, unless I'm using those archaic old-school vents over at our childrens' hospital. Our vents can be set on volume mode with a maximum inspiratory pressure such that if it reaches the set peak pressure, they alarm and simply fail to deliver the tidal volume. No risk of barotrauma, and the vents consistently deliver the TV & MV you expect them to. This is a lot more user-friendly (and just as safe) as pressure control, where changing operative conditions (such as position, pneumoperitoneum, surgeon elbow-leaning-factor) can affect your tidal volumes and require vent adjustments.

I think pressure control is more trouble than it's worth with modern vents.

 

[Stitch]

Do you routinely use volume control in kids? I never do, especially in a 10mo. Pressure control only. What do others use?

I don't have much OR experience, but in PICU or NICU it's always pressure control until about 10 kg or so.

 

[Bertelman]

Do you routinely use volume control in kids? I never do, especially in a 10mo. Pressure control only. What do others use?

I'm new to Peds- I do what my attending does. I can now count on one finger the number of kids I've anesthetized <1 yr. Maybe it's one hand.

I always use volume control, unless I'm using those archaic old-school vents over at our childrens' hospital. Our vents can be set on volume mode with a maximum inspiratory pressure such that if it reaches the set peak pressure, they alarm and simply fail to deliver the tidal volume. No risk of barotrauma, and the vents consistently deliver the TV & MV you expect them to. This is a lot more user-friendly (and just as safe) as pressure control, where changing operative conditions (such as position, pneumoperitoneum, surgeon elbow-leaning-factor) can affect your tidal volumes and require vent adjustments.

I think pressure control is more trouble than it's worth with modern vents.

Probably because of that.

 

[Bertelman]

I don't have much OR experience, but in PICU or NICU it's always pressure control until about 10 kg or so.

1) They've got sweeter vents

2) They keep kiddos vented for longer than 2-3 hrs.

 

[Licoricestick]

Licorice appears to be from that island continent so he's probably lucky enough to have it there. And sugammadex will work on other non-depolarizers, but apparently is best with roc.

Yep - I live upside down to most of you!

We have JUST (like last week!) got sugammadex in our hospital - 10 vials only on product familiarisation from the drug company (so not all that many doses). Yes, you can use it with Rocuronium and Vecuronium, although not sure about in a 10mo.

I expected cost to be an issue (it's the biggest one here and our public system doesn't bill based on individual drugs, in fact we don't bill medicare card holders at all) but didn't realise it wasn't approved by the FDA, how come?


And jwk - you called bagging something that "makes the youngsters pucker a little".... should I dare to mention I'm a first year trainee (equivalent to your CA-1 level, I think) 🙂

 

[jwk]

And jwk - you called bagging something that "makes the youngsters pucker a little".... should I dare to mention I'm a first year trainee (equivalent to your CA-1 level, I think) 🙂

LOL Not too many are doing mask anesthetics anymore - some even think it borders on malpractice. And I say youngsters because I'm an old fart in my early 50s

 

[huktonfonix]

LOL Not too many are doing mask anesthetics anymore - some even think it borders on malpractice. And I say youngsters because I'm an old fart in my early 50s

?? I know plenty of people that do mask anesthetics. Especially for short cases like myringotomies. Why is it any different than using an LMA? Unless youre talking about using like a mask and ether or something like that.

 

[aphistis]

LOL Not too many are doing mask anesthetics anymore - some even think it borders on malpractice. And I say youngsters because I'm an old fart in my early 50s

Just last week I masked a "quick washout" on a fattie that turned into a 45-minute I&D. My paperwork on that case was pretty much illegible from the cramped fingers.

 

[jwk]

?? I know plenty of people that do mask anesthetics. Especially for short cases like myringotomies. Why is it any different than using an LMA? Unless youre talking about using like a mask and ether or something like that.

Believe me, I have no problem with masks - but there just don't seem to be many people using them for doing the full case, even for things like cysto's and D&C's - they just throw in an LMA. Nobody would think of using them for long cases like we used to do years ago. The bad thing is I think a lot of people's mask technique is pretty poor because they don't have to make the effort - they get by because they can just pop in an LMA after a minute.

 

[urge]

Believe me, I have no problem with masks - but there just don't seem to be many people using them for doing the full case, even for things like cysto's and D&C's - they just throw in an LMA. Nobody would think of using them for long cases like we used to do years ago. The bad thing is I think a lot of people's mask technique is pretty poor because they don't have to make the effort - they get by because they can just pop in an LMA after a minute.

Embrace change, dude. Wacking people off left and right in the "good old days" was pretty normal. Now everything has to be perfect. This is where past experiences have taken us.

 

[pd4emergence]

I can see where JWK is coming from. We don't mask much anymore. Probably would not hurt to do some more short cases with a mask. It is a pain to chart at the same time. Of course a while back it really didn't matter that your record had a bunch of squiggley lines and nobody could read it. Now we have to have all the t's crossed and the i's dotted just in case we see our sh#tty looking record again and have to read it to the jury. Thank god for electronic records.

 

[Licoricestick]

I can see where JWK is coming from. We don't mask much anymore. Probably would not hurt to do some more short cases with a mask. It is a pain to chart at the same time. Of course a while back it really didn't matter that your record had a bunch of squiggley lines and nobody could read it. Now we have to have all the t's crossed and the i's dotted just in case we see our sh#tty looking record again and have to read it to the jury. Thank god for electronic records.

Sadly, no electronic record where I am right now, so I had the same problem with the kiddie broken arm pull case I held the mask for the other day - gave up and just wrote the record in recovery... it does give you the creppy looking over your shoulder for the lawyer feel!

But when you consider that the recommendation for airway managment in cardiac arrest is not to interrupt compressions (inc for intubation - at least in Australia) more mask practice is not a bad idea for when you get to the challenging airway where even two hands and a guedel are a stuggle.