Mechanical Ventilation - Advanced Pressure Control

[nycparrothead]

From: Critical Care Medicine Tutorials


What is the difference between Inverse Ratio Ventilation (IRV) and
Airway Pressure Release Ventilation (ARPV), Bilevel and Proportional Assist Ventilation?

We know that if a patient is hypoxic the best way to treat this is to give the patient oxygen. There comes a point when the patient will require positive pressure ventilation to enhance oxygenation. The initial support added is CPAP, which improves functional residual capacity, and places the patient on a favorable part of the pressure-volume curve (1;2). If this fails to enhance oxygenation (without the patient incurring oxygen toxicity from high FiO2 levels), then it is necessary to raise the mean airway pressure to force gas in and out of the alveoli. The patient is put on a mode of inspiratory support – volume control, pressure control or pressure support. Most patients can be easily ventilated in this way. But what if we still have trouble with oxygenation?
We know that cyclical opening and closing of injured lung units damages them (particularly if tidal volumes are large (3;4)). We would prefer if the patient could be ventilated at the top of the volume pressure curve, at high lung volumes, without phasic changes. This can be achieved using high frequency oscillation, but adult oscillators are not widely available. For the majority of patients, increasing mean airway pressure without increasing peak pressure means prolonging the inspiratory time in a pressure control mode. The longer the inspiratory time (Ti), the better the oxygenation benefit.
A new method of achieving this uses a modification of ARPV (airway pressure release ventilation) (5). In conventional ventilation, the baseline airway pressure is the PEEP or CPAP level, and ventilator cycling involves application of positive pressure to a higher airway pressure level: the purpose of cycling is CO2 removal. The idea of ARPV is that the ventilator cycles between two different levels of CPAP – an upper pressure level and a lower level. The two levels are required to allow gas move in and out of the lung. The key element of ARPV is that the baseline airway pressure is the upper CPAP level, and the pressure is intermittently “released” to a lower level, thus eliminating waste gas.
Bilevel ventilation (6) or BIPAP (which is often confused with BiPAP, a form of non invasive ventilation), is ARPV with spontaneous breathing. A sophisticated valve has been developed which allows the patient to breath spontaneously at either CPAP/PEEP levels, and partial assistance (pressure support or automatic tube compensation) can be introduced to assist the spontaneous breaths. This mode appears to be extremely well tolerated, and heavy sedation is not required (it is in APRV and IRV).

[buffettbride]

Those are some awfully big words. It's probably good that you could cut and paste them.

[tommcat327]

what an excellent article shane,i have learned alot today

[aquaholic]

Now were posting good stuff thanks NYC!!!!!!...............

[PHBeerman]

Damn it scares me that this makes sense. I blame my wife....

[nycparrothead]

Damn it scares me that this makes sense. I blame my wife....

If you don't like it you don't have to read it!! Some people find it interesting and I don't need to sit here and keep quiet while you attack me!!!

[buffettbride]

Damn it scares me that this makes sense. I blame my wife....

If you don't like it you don't have to read it!! Some people find it interesting and I don't need to sit here and keep quiet while you attack me!!!

Yeah Beerman. Stay of his back. He's a poor defenseless monkey.

[jollymon345]

Can someone please explain the big words to me?

[Elrod]

Can someone please explain the big words to me?

Pink is good, blue is bad, air should go in and out.

[jollymon345]

Can someone please explain the big words to me?

Pink is good, blue is bad, air should go in and out.

Got it!

[PHBeerman]

Damn it scares me that this makes sense. I blame my wife....

If you don't like it you don't have to read it!! Some people find it interesting and I don't need to sit here and keep quiet while you attack me!!!

Have you seen this one yet?

http://www.rollingstone.com/news/story/ ... on=single1

Strait, Not Usher, on Top

Processing error leads to Nielsen SoundScan recount



Due to a merchant processing error, Nielsen SoundScan re-tallied its albums chart today, leading to a new Number One: country star George Strait, whose 50 Number Ones sold 343,000 copies rather than the 336,000 reported earlier.
With the recount, R&B breakout star Usher was bumped down to Number Two. The repackaged version of his runaway hit album Confessions -- featuring three new tracks, including a duet with Alicia Keys -- sold 336,000 copies this week.

Another error in today's tally placed R.E.M.'s Around the Sun at Number Fourteen: they also got a promotion -- but only one spot, to Thirteen, with 61,000 sold rather than the reported 59,000.

This week's Top Ten: George Strait's 50 Number Ones; Usher's Confessions; Good Charlotte's Chronicles of Life and Death; Korn's Greatest Hits, Vol.1; Nelly's Suit; Hilary Duff's Hilary Duff; Green Day's American Idiot; Rascal Flatts' Feels Like Today; Tim McGraw's Live Like You Were Dying; Ciara's Goodies.



ALEX MAR
(Posted Oct 13, 2004)

[nycparrothead]

Damn it scares me that this makes sense. I blame my wife....

If you don't like it you don't have to read it!! Some people find it interesting and I don't need to sit here and keep quiet while you attack me!!!

Have you seen this one yet?

http://www.rollingstone.com/news/story/ ... on=single1

Strait, Not Usher, on Top

Processing error leads to Nielsen SoundScan recount



Due to a merchant processing error, Nielsen SoundScan re-tallied its albums chart today, leading to a new Number One: country star George Strait, whose 50 Number Ones sold 343,000 copies rather than the 336,000 reported earlier.
With the recount, R&B breakout star Usher was bumped down to Number Two. The repackaged version of his runaway hit album Confessions -- featuring three new tracks, including a duet with Alicia Keys -- sold 336,000 copies this week.

Another error in today's tally placed R.E.M.'s Around the Sun at Number Fourteen: they also got a promotion -- but only one spot, to Thirteen, with 61,000 sold rather than the reported 59,000.

This week's Top Ten: George Strait's 50 Number Ones; Usher's Confessions; Good Charlotte's Chronicles of Life and Death; Korn's Greatest Hits, Vol.1; Nelly's Suit; Hilary Duff's Hilary Duff; Green Day's American Idiot; Rascal Flatts' Feels Like Today; Tim McGraw's Live Like You Were Dying; Ciara's Goodies.



ALEX MAR
(Posted Oct 13, 2004)

Only a tool like you would post a Rolling Stone article in a thread as serious as this one.

[Mr Play]

We know that if a patient is hypoxic the best way to treat this is to give the patient oxygen.

That's like saying, "We know that if a person is starving the best way to treat this is to give the person some food".

And YEEHAW for George Strait!

[ragtopW]

Is this a big issue??? I like my c-pap. It's my best Friend.