POST YOUR INTERESTING OR DIFFICULT VENTILATION CASE HERE.

Tell everyone what you did and how it worked(non-invasive or invasive). Use this thread to educate. And remember,What might be second nature to some could be education for others.

I have been pondering, recalling, etc., several cases of interest over the years. I need to go polish it off in a series of interesting cases in MS Word and then I'll submit.

I am interested in all cases, but would request as many as possible with APRV. I have a very evidence based medical director, and I will be using your cases to support it's use.

GJ

Interesting Ventilator Episodes.

Sometimes you can make a difference by just not being another in a line of buffoons. Sometimes you can make a difference and get recognized, but often it's under the radar.

The first tale below deals with the PB MA-1 Ventilator. This was one of the very early volume control ventilators which took over from the Birds and PR-2's. A brief description is in order. The only mode available was volume assist control. Later models were retro-fitted for IMV---one had to dial out the sensitivity and either 1) setup an H system which the patient had to draw off of, or 2) blast continuous flow through the system thereby removing any ability to have a volume alarm. The ventilator only came with a built in high pressure alarm. One had to attach a "bellows" with an independent battery powered alarm"”one which wasn't an integral part of the ventilator. In a way like how the low pressure alarm is added to Bipap in the STD models. The response time was sluggish. If any Peep was dialed in one had to then go and increase the sensitivity----the sensitivity didn't automatically "tag along" as Peep was raised or lowered.

I had graduated from RT school about one year earlier. I had spent a large amount of that time working and getting "broken in" after moving out of the area so that I could work in a more progressive hospital, "RT-wise" at least.

But for personal reasons I had to return to the Bay Area, time frame roughly 1983. I had signed up for a registry assignment and took a shift at a nearby hospital. Now this hospital was renowned for both paying a bit more than the average AND for having one of the worst RT dept.'s in the area. In retrospect I strongly feel that it was because the RT dept. was under nursing. Nursing didn't know how to pick a good RT from a total dud, plus had a default agenda to place us as low on the professional pecking order/status as could be. Ye shall reap what ye sow.

Anyway I showed up for report and was told that one of my patients on a ventilator was a doctor whom worked at the hospital. My attempted humorous reply was "is he getting a taste of his own medicine?"

He was a middle aged man with ARDS. His settings were VT 500, RR 14, FIO2 1.0 and Peep of 12. The outgoing therapist remarked to me, "He seems to be breathing as fast as he can". Then I was shown his last ABG's...pH 7.29 PaCO2 49 PaO2 63. On 100% O2 and Peep 12.

I wasn't even shown the ICU, just shown the charting paper and told to ask the nurses if/when I needed anything. I had several other patients but none seemed as bad per report as this one did. So I walked into the room. I will never forget what I saw and heard.

A patient on the ventilator was wide awake and obviously with much labored respirations. The RN was stooped over in the corner and picking up some dirty linen. As she arose she stated, "He is on what you call ˜assist control'. He doesn't seem to be getting much of the assist." Indeed.

I walked over to the ventilator and looked at the dials and the pressure manometer (NO WAVEFORMS).

The flow rate was set at 40 liters a minute. That, combined with an awake patient on a 500cc VT trying to basically suck the whole ventilator down his ET tube, meant no high pressure alarms were going off. No low volume alarms were going off either as the patient was huffing and puffing.

But it didn't stop there. The sensitivity had not been reference to the Peep. This patient had to pull negative about 14 JUST TO START THE AIR MOVING and even then it was a mere 500 cc's at 40L/M. This patient was about 5'1`0" tall so 500 per ARDSnet wouldn't be that bad IF he was sedated. But he was probably giving himself also a big of negative pressure pulmonary edema.

This all happened fast and I recall saying ala a pronouncement "every breath is an incentive spirometry maneuver". I quickly referenced the sensitivity to the Peep, turned up VT towards his demand (700 cc's just began to scratch that surface), and cranked the flow rate up until I didn't see the pressure decay on the manometer.

The next ABG's came back with normal pH and PaCO2. And the PaO2 was 130. I heard he eventually walked out of the hospital.

But had someone not noticed these elementary things awry this patient might have supposedly died of ARDS when in fact the ventilator was being used as a kind of suffocation device. This was with 8 hour shifts so I told the next shift what had happened and explained how they need to reference the sensitivity to the peep.

Next story...fast forward to about 2003.

I was working at a teaching hospital. I got a call from a distressed therapist that a patient was drastically losing ground on oxygenation and ventilation despite very aggressive PC settings. They had moved him from a one type of ventilator to the next (exact types not important except one didn't have APRV option). This patient had a relatively clear left lung, but the right one looked very ugly on CXR. Not quite white out. I forget the exact settings on PC but the FIO2 was 1.0. pH was 6.9 with a high PaCO2. The PaO2 number escapes me but it was not much greater than 60.

I put the patient on APRV with the following settings. P High 45 P Low 0 Time High 0.6 seconds Time Low 0.4 seconds. Total RR was 60. Mean airway pressure was about 24. As the THAM was being bought over to buffer the pH the ABG subsequently gave a pH of about 7.37 with much lower CO2. The PaO2 modestly improved as well. What I think happened was that with larger distending pressures in PC the uneven distribution of VT favored more normal left lung over the right. So perfusion to right lung and overdistension/ventilator left lung. By using APRV as a kind of "poor man's oscillator" (he was paralyzed and free breathing had nothing to do with it), both lungs were kept open more by mean airway pressure. No part of the lungs probably ever saw the P High of 45, nor did any lungs see P Low of 0. Imagine two people holding a very long rug at both ends such that it extends across the street. One person holds his end on the ground while the other one whips his end up 15 feet. Out in the middle of the rug the highs and lows would be a "mean rug height". This hospital had a practice of starting out on SIMV (and any move to A/C would bring out the crucifixes and garlic). If the patient got worse then they got moved to PC. If the patient got better then the transition was to MMV and later PS "weans" ala a Barbeque Cook doing a Boston Butt over 24 hours. APRV was not in the equation and had basically never been used before. I could have used PC and done exactly the same thing. But with APRV I had "the mystique of the mode" such that it acted like a smoke grenade under cover of which I make the necessary and beneficial changes. This all happened about 5AM (I was called in from home). In morning rounds the attending was obviously unhappy that the patient was on a mode he knew little or nothing about. So he mentioned "let's put him on SIMV". The interns and residents whom were there that morning for the "fireworks" about revolted on the spot.

Several years earlier I had come up with the idea on my own that the APRV on Drager could be used as a form of an oscillator. A while earlier at a conference I had asked the HFOV Vent rep to show me (test lung----actually in the shape of a lung) what adult settings would look like. It reminded me a lot of the chest wiggle of IPV as opposed to the neonatal HFOV I had witnessed. I then went over to a Drager Vent and, after the rep arguing with me "that isn't what APRV is for" and he left the vent for me to play with on my own. I wanted to see how much I could extend out to HFOV settings. I set it to a rate of almost 300 with both times high and low 0.1 seconds. But with meaningful pressure swings the vent would go crazy. I left the ventilator that way and walked over to a nearby booth. I looked back and another Drager rep had come upon the vent and I can still recall the "WTF" look on his face.

Third Case.

I had been called to see a floor ward patient because the nurse was having trouble keeping the patient oxygenated. I forget the specifics of why this patient's oxygenation was so bad. It was pneumonia, but I forget any other details of what started it all. The patient was on a NRB mask and only had an SpO2 of from 85 to 90. This was pre Aquinox/Vapotherm. I turned up the flow and it didn't make anymore than a marginal difference. I tried positioning the patient and the patient being on one side made her oxygenation a bit better. All the other vital signs were OK, no sepsis, etc.

Now the patient was an adamant DNR/DNI. But, despite being alert and aware, she kept wanting/attempting to take the mask off, asking how long she needed to wear it. She didn't seem to have any idea of how precarious her situation was. I made it a big point to tell her she needed to keep her oxygen on. We put a continuous oximeter in the room and cranked the alarm volume up, kept the door open, etc. I regularly checked on her and she did keep the mask on. But, while she didn't decompensate, we basically were treading water as far as the oxygenation went that night.

Her doctor was down the hall dictating on another patient. I briefly talked to the MD and the general take was that all the antibiotics were in, something to the effect of "we've done all we can do for now". I considered and mentioned Bipap but as the patient was barely tolerating even a mask that was not ordered.

I was off work for several days and then returned to work. This patient had been later the following morning (I was working the night shift) placed on Bipap (a Pulmonologist had been called in) and was on it now for about 2-3 days. I had the patient that evening. She had been moved to a monitored room, but not in ICU. The Bipap settings had been FIO2 0.9 to 1.0 for the entire time she was on Bipap. The Bipap settings were now something like 16/12. The patient was now starting to get very tired of the Bipap and so sedation was ordered to help confer some compliance. I went in and still the patient was trying to take the mask off. It was about midnight.

I considered her oxygenagtion status and history, that she was a DNR/DNI whom might die if not intubated--or if she took off her Bipap. I asked the nurse to give the patient as much sedation as she was allowed to do, which the RN did. I then stayed with the patient for about another hour. I turned up the Bipap to 25/18 (in sessions) and turned the rate up to 40 with a 1:1 I:E ratio. I watched her SpO2. When I left the room, about an hour later, I was able to turn the FIO2 down to 0.5. And it stayed FIO2 0.50, later down to 0.4 and then to nasal cannula. I aslo turned down the Bipap to something a bit higher (18/14 I think).

The patient made it off the Bipap and made it home.

The next day I was told the MD was irked and wrote an order "don't turn up the pressures". I was flabbergasted and asked something like "I thought the MD would basically want to kiss my gluteus maximus for getting that patient better". I was then told that "Dr. X always needs to be the one that fixes her patients".

Fourth Case.

A severe COPD patient had traveled out from the Midwest and was at our hospital. He was being worked up for a lung transplant at a local hospital (we didn't do them). I saw him briefly (routine RT treatments) before he left for the transplant.

A while later he came back to us. He not only had a transplant of one lung. His other lung still had such bad COPD that they did lung volume reduction surgery (LVRS) on that one. He was trached and considered ventilator dependent.

When he got distressed you could stand at the foot of the bed and see how the LVRS lung was still air- trapping. After a while of being distressed (wean or excitement) and tachypneic one could see a marked difference in how the lungs filled and emptied. From memory I think that what happened was that the "bad lung" would push against the good lung, but also pushing air out on exh. Then on insp. first the non-LVRS lung would fill, the air would trap.

Anyway, the patient was placed on Bipap to his trache and a bizarre "weaning" ritual was done. Every day we were to turn down his Bipap settings. But the patient had also a lot of anxiety, or maybe he just didn't tolerate it being turned down below some threshold. But definitely any anxiety and resultant ventilation increase only made things worse. Then one RT got the "bright idea" to just go in and turn down the Bipap without telling him. Well that seemed to "work" for a bit. Until the patient found out what people were doing (RN walks in room and announces or asks, hence it got exposed). So now the patient was anxious, pissed, and everytime you walked in your were also suspect.

I had the patient placed in bed. While on Bipap didn't turn the Bipap down at all. I had the patient relax and then turned the Bipap off completely. I deflated his cuff and quickly placed a Passy Muir valve on him. His FIO2 had been 0.30 on Bipap with SpO2's mid to high 90's. So he was on room air. No sounds of a ventilator, no sound of any Bipap or mist. No one had ever tried a PM valve before with him. We talked for ½ hour and his SpO2 didn't go below 94. He wasn't tachypneic or distressed at all. He hadn't talked for about 2 years by this point. The RN bought in a phone and he called his wife, left a message (she was nearby). I would have loved to have been there when she took her messages off the machine!

I explained to the patient that he might be fine on his own while relaxed, but any excitement of increased ventilatory demand and it might overly tax him. When he left us he was still going on the ventilator (Bipap or Lifecare) at night.

So I look back on this as a variation of the old "wean" nonsense vs. full support and then a daily SBT (the SBT in this case being a belated PM trial). The patient then went on PM daily and prn, making rapid progress and eventually making it home.

WOW! Great cases.