Tough Crani

[narcusprince]

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Yesterday's case was very interesting. 34 y/o w history of OLT @10 years of age, now with ESRD on CRRT, end stage liver disease, profoundly anemic Hgb 6.7/ 20 mental status altered sedated intubated now with posterior fossa possible cerebellum bleed, also profoundly coagulapathic Factor 7 given at the bedside which in addition to 8 units of FFP corrected the coagulopathy. Started the case with the belmont hooked into the subclavian quinton catheter infusions through IJ double lumen. Started the case on Norepinephrine pt was in florid urosepsis VRE in urine as soon as the agent was turned on bp tanked added some epinephrine(thought process was that she was on heavy dose of NE 10mcg/min must be a contractility issue) Could not transfuse the CVP as we had too many infusions hooked in. Bleeding was profuse throughout the case lost about 3.0L of blood. Transfused roughly 6 units prbc and 6 units of ftp 2 five packs of platelets also gave Novaseven during the case(not very good evidence to use Nova7 inter operatively) . Another good clinical pearl pt was in presumed DIC you give 1U of FFP for every unit of PRBC given. At the end of the case we kept the patient intubated. Vent settings were quite high PEEP of 8, peak pressures with adequate TV 6ml/kg in the 40's likely this was early ARDS. Called for an ICU ventilator because of the high vent settings high peep and Pinsp. It could be presumed that her respiratory failure was secondary to decrease compliance, my staff advocated for shorter inspiratory times( I thought this was wrong in that her Peak pressures were equal to her plateau pressures IE her problem was a compliance issue. Using this equation Ppk=VT/C + Flow rate x resistance. Her issues were all compliance related so any increase in Peak pressure would be transmitted to the alveolus resulting in barotrauma, atelectrauma, and worsening our situation.

To the old school guys what are the advantages of an ICU ventilator over a anesthesia machine ventilator? We all understand better PEEP settings, and more efficient volumes.

 

[jdh71]

Is a PEEP of 8 high on an anesthesia machine? And were peak and plat so close they appeared to be the same, because I'm not sure how it's even physically possible for them to both be the same?

Sounds like the kind of case where everyone it scratching their heads about why the patient is even in the OR in the first place.

 

[Idiopathic]

Yesterday's case was very interesting. 34 y/o w history of OLT @10 years of age, now with ESRD on CRRT, end stage liver disease, profoundly anemic Hgb 6.7/ 20 mental status altered sedated intubated now with posterior fossa possible cerebellum bleed, also profoundly coagulapathic Factor 7 given at the bedside which in addition to 8 units of FFP corrected the coagulopathy. Started the case with the belmont hooked into the subclavian quinton catheter infusions through IJ double lumen. Started the case on Norepinephrine pt was in florid urosepsis VRE in urine as soon as the agent was turned on bp tanked added some epinephrine(thought process was that she was on heavy dose of NE 10mcg/min must be a contractility issue) Could not transfuse the CVP as we had too many infusions hooked in. Bleeding was profuse throughout the case lost about 3.0L of blood. Transfused roughly 6 units prbc and 6 units of ftp 2 five packs of platelets also gave Novaseven during the case(not very good evidence to use Nova7 inter operatively) . Another good clinical pearl pt was in presumed DIC you give 1U of FFP for every unit of PRBC given. At the end of the case we kept the patient intubated. Vent settings were quite high PEEP of 8, peak pressures with adequate TV 6ml/kg in the 40's likely this was early ARDS. Called for an ICU ventilator because of the high vent settings high peep and Pinsp. It could be presumed that her respiratory failure was secondary to decrease compliance, my staff advocated for shorter inspiratory times( I thought this was wrong in that her Peak pressures were equal to her plateau pressures IE her problem was a compliance issue. Using this equation Ppk=VT/C + Flow rate x resistance. Her issues were all compliance related so any increase in Peak pressure would be transmitted to the alveolus resulting in barotrauma, atelectrauma, and worsening our situation.

To the old school guys what are the advantages of an ICU ventilator over a anesthesia machine ventilator? We all understand better PEEP settings, and more efficient volumes.

since you thought this was wrong, what was your suggestion?

 

[MTGas2B]

Yesterday's case was very interesting. 34 y/o w history of OLT @10 years of age, now with ESRD on CRRT, end stage liver disease, profoundly anemic Hgb 6.7/ 20 mental status altered sedated intubated now with posterior fossa possible cerebellum bleed, also profoundly coagulapathic Factor 7 given at the bedside which in addition to 8 units of FFP corrected the coagulopathy. Started the case with the belmont hooked into the subclavian quinton catheter infusions through IJ double lumen. Started the case on Norepinephrine pt was in florid urosepsis VRE in urine as soon as the agent was turned on bp tanked added some epinephrine(thought process was that she was on heavy dose of NE 10mcg/min must be a contractility issue) Could not transfuse the CVP as we had too many infusions hooked in. Bleeding was profuse throughout the case lost about 3.0L of blood. Transfused roughly 6 units prbc and 6 units of ftp 2 five packs of platelets also gave Novaseven during the case(not very good evidence to use Nova7 inter operatively) . Another good clinical pearl pt was in presumed DIC you give 1U of FFP for every unit of PRBC given. At the end of the case we kept the patient intubated. Vent settings were quite high PEEP of 8, peak pressures with adequate TV 6ml/kg in the 40's likely this was early ARDS. Called for an ICU ventilator because of the high vent settings high peep and Pinsp. It could be presumed that her respiratory failure was secondary to decrease compliance, my staff advocated for shorter inspiratory times( I thought this was wrong in that her Peak pressures were equal to her plateau pressures IE her problem was a compliance issue. Using this equation Ppk=VT/C + Flow rate x resistance. Her issues were all compliance related so any increase in Peak pressure would be transmitted to the alveolus resulting in barotrauma, atelectrauma, and worsening our situation.

To the old school guys what are the advantages of an ICU ventilator over a anesthesia machine ventilator? We all understand better PEEP settings, and more efficient volumes.

Sounds like a rough case. A few questions.

1. I assume she was prone (posterior fossa bleed). Did the peak pressures improve once you flipped the patient back over? While prone ventilatoin can improve ventilation perfusion matching, if you were using a regular OR bed with chest roles it could crank up chest wall compliance.

2. You mentioned you were cranking up the peep, I assume you were checking blood gasses. I'm curious what the P/F ratios were looking like. Or were you just going by sats? Did you try any recruting maneuvers?

3. Final thought, other possiblity, especially with all of blood products any thoughts it could have been TRALI? I'd be curious how the number were looking post back in the unit. Signs of progressing ARDS versus improvement.


ICU vents have a few advantages. First, you get more information. You can measure static pressure, which can be helpful in a case like this when you're trying to figure out why your peak pressure is so darn high. You really need to look at statics to tweak your ARDS therapy. Depending on the limits of your OR vents, you may need an ICU vent just to keep up patients who have high minute veniltation (with rip roaring sepsis and ARDS you increased CO2 production increased dead space ventilation, bad combo). Back when I was in training, our trauma/neuro hospital had old Draeger Narcomeds in the ORs (they've mostly been replaced now). I want to say they really couldn't handle minute volumes beyond the high teens. The other thing you mentioned is PEEP, a lot of OR vents can't handle higher PEEPS, ICU vents can do more. Plus, one of my things, some ICU vents can measure esophageal pressures which you can use to approximate pleural pressure and ramp up your PEEP, some people may need 20 of PEEP, its hard to know who they are. I don't know how well they work prone though.

My $0.02

 

[W222]

To the old school guys what are the advantages of an ICU ventilator over a anesthesia machine ventilator? We all understand better PEEP settings, and more efficient volumes.

Just a few things to add to the rest. If ARDS was a concern and things were going south, you could try high freq. oscilation vent to improve oxygenation. Also, some studies have shown benefit with verticle/upright positioning and prone positioning.

 

[Idiopathic]

its hard to tell what your main problem was. did you need the high peak pressures to ventilate effectively? could you oxygenate? 8 of PEEP is not that high, especially if you are considering ARDS/TRALI. If oxygenation is your concern, you could do a modified bi-level ventilatory strategy with shorter E times, obviously this will result in CO2 retention which may not be ideal in the craniotomy patient. (or the uremic/hepatic failure patient for that matter) but oxygenation ultimately has to take precedence. this can be done for a time in the OR without the need for an ICU vent

also, just as prone positioning or patient rotation may be beneficial, the acuity of a supine flip after acclimation to prone positioning likely would have had a major negative impact on the pulmonary status.

extrapleural compression also a possibility (large volume ascites?)

 

[MTGas2B]

obviously this will result in CO2 retention which may not be ideal in the craniotomy patient

Can't wait until someone markets extracorporeal CO2 removal for severe ARDS. Just keep this PaO2 at a minimal survivable level, and don't sweat crazy ventilation strategies to keep the PaCO2 down.

 

[Idiopathic]

Can't wait until someone markets extracorporeal CO2 removal for severe ARDS. Just keep this PaO2 at a minimal survivable level, and don't sweat crazy ventilation strategies to keep the PaCO2 down.

just modify hemodialysis therapy a little

 

[MTGas2B]

just modify hemodialysis therapy a little

can crank the bicarb in the bath, a bit, but with severe ards that may not be enough

plus you can fix the ph, but you're fighting high CO2 with high bicarb. When its done you're gonna have some deranged electrolytes to fix

I'm not entirely convinced on the benefits of permissive/therapeutic hypercapnea

 

[Idiopathic]

its been studied in kids i think, it can be done. ill look for the resource

 

[MTGas2B]

its been studied in kids i think, it can be done. ill look for the resource

The only adult data I'm aware of is post hoc analysis of the original ards net low tidal volume study. They showed increased survival in folks who had higher CO2.

The animal data is more robust, but its equivocal. Some studies show benefit (mainly inflammatory markers) in rat models. Some show increased inflammatory markers.

There was a pilot study of an extracoporeal co2 removal device published in Anesthesiology a few years ago. If someone can get one to market then I think we can do the real study to see if hypercapnea hurts or helps. Hook up the machine, dial in the randomized CO2 value you've been assigned in the study.

 

[Mman]

To the old school guys what are the advantages of an ICU ventilator over a anesthesia machine ventilator? We all understand better PEEP settings, and more efficient volumes.

I'm assuming this patient has a chance of surviving to hospital discharge of less than 1% so any benefit from a different ventilator is sort of theoretical.

I think the answer is that it depends on how old the vent is on your anesthesia machine. Newer machines are coming with nicer and fancier vents. Still not quite as good as topnotch ICU vents but they work well for almost any case you'll find in the OR.

 

[MTGas2B]

narcusprince, just out of curiosity what kind of anesthesia machine were you using?

 

[proman]

There was a pilot study of an extracoporeal co2 removal device published in Anesthesiology a few years ago. If someone can get one to market then I think we can do the real study to see if hypercapnea hurts or helps. Hook up the machine, dial in the randomized CO2 value you've been assigned in the study.

It's the Novalung www.novalung.org Not available in the US. The CESAR trial looked at ECMO vs conventional ventilation for ARDS.

 

[MTGas2B]

It's the Novalung www.novalung.org Not available in the US. The CESAR trial looked at ECMO vs conventional ventilation for ARDS.

This is the one I was thinking of
http://journals.lww.com/anesthesiology/pages/articleviewer.aspx?year=2009&issue=10000&article=00026&type=abstract

I think the CO2 elimination is the biggest key, this one uses venous-venous removal, unlike ECMO. I think it could the kind of thing an intensivist could place the catheter for and manage on their own without needing a surgeon like ECMO. It would be like managing CVVH.

extracorporeal carbon dioxide removal was initiated
by using amodified continuous veno-venous hemofiltration
system equipped with a membrane lung with a total membrane
surface of 0.33 m2 (Decap®, Hemodec, Salerno, Italy)
19 (Lower ARDSNet/Carbon Dioxide Removal; fig. 2).


I can't access the novolung website from my tent in the desert, so I can't tell if it does what these guys did.

For those following along at home here's the CESAR abstract
http://www.ncbi.nlm.nih.gov/pubmed/19762075

 

[proman]

This is the one I was thinking of
http://journals.lww.com/anesthesiology/pages/articleviewer.aspx?year=2009&issue=10000&article=00026&type=abstract

I think the CO2 elimination is the biggest key, this one uses venous-venous removal, unlike ECMO. I think it could the kind of thing an intensivist could place the catheter for and manage on their own without needing a surgeon like ECMO. It would be like managing CVVH.

Looking at the paper, they used a conventional VV ECMO neonatal circuit with a 14 french double lumen femoral venous catheter. The Avalon catheter is frequently used for adult VV ECMO. It's a 24 french line designed for the IJ. Seems like the Novalung is close to the neonatal circuit in design. I could see the website by saying I was logging in from Canada.

 

[dhb]

I saw the Novalung used once in is case that went something like this:

Post-partum hemorhrage -> hysterectomy -> massive PE -> pulmonary endarterectomy -> Novalung -> lung transplant -> +- ECMO to survival

 

[imfrankie]

I saw the Novalung used once in is case that went something like this:

Post-partum hemorhrage -> hysterectomy -> massive PE -> pulmonary endarterectomy -> Novalung -> lung transplant -> +- ECMO to survival

Gadzooks that's a long day

 

[Idiopathic]

Gadzooks that's a long month

.

 

[MTGas2B]

Gadzooks that's a long day

Lung transplant for massive PE, that's a going to be miserable life.

 

[MTGas2B]

Looking at the paper, they used a conventional VV ECMO neonatal circuit with a 14 french double lumen femoral venous catheter. The Avalon catheter is frequently used for adult VV ECMO. It's a 24 french line designed for the IJ. Seems like the Novalung is close to the neonatal circuit in design. I could see the website by saying I was logging in from Canada.

They block some pretty random sites over here.

 

[W222]

I saw the Novalung used once in is case that went something like this:

Post-partum hemorhrage -> hysterectomy -> massive PE -> pulmonary endarterectomy -> Novalung -> lung transplant -> +- ECMO to survival

Where the F--- do you work? Your surgeons should have their heads examined.

 

[dhb]

Gadzooks that's a long day

it was over several weeks

 

[dhb]

Where the F--- do you work? Your surgeons should have their heads examined.

maybe, they did kind of save her life...

 

[narcusprince]

since you thought this was wrong, what was your suggestion?

My suggestion was to increase the I time to decrease the peak pressures. My staff disagreed. We called an ICU ventilator and placed the patient on PCV and 8 of PEEP and brought them to the unit with peak pressures still at 45.

 

[narcusprince]

Sounds like a rough case. A few questions.

1. I assume she was prone (posterior fossa bleed). Did the peak pressures improve once you flipped the patient back over? While prone ventilatoin can improve ventilation perfusion matching, if you were using a regular OR bed with chest roles it could crank up chest wall compliance.
Pressures were sustained through prone and supine positioning.

2. You mentioned you were cranking up the peep, I assume you were checking blood gasses. I'm curious what the P/F ratios were looking like. Or were you just going by sats? Did you try any recruting maneuvers?

P/F ration was poor 150/1. Sats improved with peep the issue was hypercapnia in a neuro patients. Tried sustauined positive pressure for 30 seconds did not really improve situation.

3. Final thought, other possiblity, especially with all of blood products any thoughts it could have been TRALI? I'd be curious how the number were looking post back in the unit. Signs of progressing ARDS versus improvement.
TRALI was high on the list. Looks like she is in ARDS currently she had also beein in urosepsis, my thinking that she was developing ARDS in the lungs secondary to urosepsis and the generalized inflammatory, cytokine mediated state. But TRALI is still on the list.

ICU vents have a few advantages. First, you get more information. You can measure static pressure, which can be helpful in a case like this when you're trying to figure out why your peak pressure is so darn high. You really need to look at statics to tweak your ARDS therapy. Depending on the limits of your OR vents, you may need an ICU vent just to keep up patients who have high minute veniltation (with rip roaring sepsis and ARDS you increased CO2 production increased dead space ventilation, bad combo). Back when I was in training, our trauma/neuro hospital had old Draeger Narcomeds in the ORs (they've mostly been replaced now). I want to say they really couldn't handle minute volumes beyond the high teens. The other thing you mentioned is PEEP, a lot of OR vents can't handle higher PEEPS, ICU vents can do more. Plus, one of my things, some ICU vents can measure esophageal pressures which you can use to approximate pleural pressure and ramp up your PEEP, some people may need 20 of PEEP, its hard to know who they are. I don't know how well they work prone though.

My $0.02

Thanks for the response

 

[narcusprince]

narcusprince, just out of curiosity what kind of anesthesia machine were you using?

Datex Ohmedia aisys.

 

[dhb]

We called an ICU ventilator and placed the patient on PCV and 8 of PEEP and brought them to the unit with peak pressures still at 45.

PCV peak pressure 45? doesn't make sense unless you chose those settings

 

[narcusprince]

PCV peak pressure 45? doesn't make sense unless you chose those settings

Pcv-vg.

 

[gtb]

Where the F--- do you work? Your surgeons should have their heads examined.

Why do you say that? I have no idea what the real clinical picture was. However, maybe this new mother was an otherwise healthy, young woman with an isolated lung problem not amenable to thrombectomy, and is potentially fixed by a transplant. A multidisciplinary team is involved in making the decision for any transplant, but certainly the CT team decides whether they are the ones best capable of performing such a procedure. When considering some of the patients histories and lifestyles that we routinely transplant, its hard for me to imagine anyone having a question about going forward with a patient like this. It's all conjecture though since I do not have any clue what the real story is.