CPAP with DLT

[deleted875186]

How do people do CPAP to the non ventilated lung during one lung ventilation for a patient that keeps desating? There doesn’t seem to be any safe way to do it at my hospital, other than simply not completely deflating the lung at the start of the procedure.

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[GhostTree]

I use the suction catheter from the dlt pack and connect it with suction tubing to the o2 outlet on the machine, like you would a nasal cannula. It’s more intermittent oxygenation than true cpap but it keeps th sat up. Just once in a while I occlude the hole on the tubing and oxygenate.

Why do you say there’s not a safe way to do it?

 

[B-Bone]

we use this device:

It has a dial to select the level of CPAP (basically a pop-off). Hook up auxillary O2, select CPAP level. Hook other lumen up to ventilator. Easy peasy.

 

[DesiredMemberName?]

Attach a mapleson to the lumen going to the operative lung. Attach aux O2 from the anesthesia machine to the mapleson. Adjust APL valve on mapleson for desired CPAP. If you have a pressure gauge, you can transduce the pressure from a sideport on the mapleson if present, but this is probably not necessary.

 

[pgg]

I use the suction catheter from the dlt pack and connect it with suction tubing to the o2 outlet on the machine, like you would a nasal cannula. It’s more intermittent oxygenation than true cpap but it keeps th sat up. Just once in a while I occlude the hole on the tubing and oxygenate.

This is essentially apneic oxygenation of the non-ventilated lung. It works very well and doesn't inflate the lung. I've rarely had to move on to actual CPAP or intermittent ventilation after doing this.


To apply actual CPAP to the non-ventilated lung, the easiest thing to do is connect a separate BVM or Mapleson circuit to the aux O2 port and set the valve on it to whatever pressure value you want.

 

[deleted697535]

Mapleson C.
Why you guys bother with horrible heavy useless ambu bags on every cart is beyond me and only 1 mapleson cct per hospital!

Edit to clarify. I think ambu bags are crap but seem to be everywhere in North america

 

[pgg]

Why you guys bother with horrible heavy useless ambu bags on every cart is beyond me and only 1 mapleson cct per hospital!

What?

 

[Ronin786]

When you guys are using CPAP, how frequently are your surgeons complaining of poor isolation?

 

[jonessoda1212]

When you guys are using CPAP, how frequently are your surgeons complaining of poor isolation?

Less than they complain with intermittent two lung ventilation.

 

[pgg]

When you guys are using CPAP, how frequently are your surgeons complaining of poor isolation?

Good surgeons never complain ... 🙂

If you try the apneic oxygenation thing with the suction catheter as described above, you'll almost never need CPAP. I can't remember the last time I did. Probably as a fellow because I was told to.

 

[Ronin786]

Good surgeons never complain ... 🙂

If you try the apneic oxygenation thing with the suction catheter as described above, you'll almost never need CPAP. I can't remember the last time I did. Probably as a fellow because I was told to.

I've tried that and I'm definitely a fan. Did an esophagectomy the other day where I just couldn't get it to work and had to utilize the CPAP (was actually my first time). It definitely made life a lot easier, but I could visibly see some inflation at points in time. Like you said, good surgeon mixed with a case where they're not working on the lung anyways meant I got away with it, but I could see the potential for complaint.

 

[cchoukal]

As others have said, passive oxygenation first, although you have to be careful with the size of the tubing and rate of flow; I've seen lung inflation just from this if the tubing is large enough to create even a transient seal with the inner diameter of the DLT. When CPAP is necessary, you really do need a dedicated device (I use the one B-Bone showed; maybe that's because we went to the same medical school). Even on these, I find you have to keep the flows low to limit inflation of the non-dependent lung.

As for the complaints about the ambu-bag, yes they're bulky, but it's that bulk that makes them self-inflating (their defining characteristic and a critical safety feature). Try ventilating someone with a Mapleson without a source of oxygen sometime.

 

[nimbus]

You can also PPV the ”nonventilated” lung by hand with the mapleson or ambu-bag. I give small microbreaths while watching the monitor during VATS. Or I give slightly bigger breaths in coordination with the surgeon. Just talk to the surgeon. It’s saved me many times from having to fully reinflate the down lung in order to maintain adequate oxygenation.