What is PEEP? How to do a PEEP study?

PEEP is an abbreviation for Positive End Expiratory Pressure. It's a small amount of pressure above what is in room air that remains at the end of expiration.

The benefits of PEEP are.

1. Increased Residual Capacity. This essentially means that it increases the amount of air that stays in the lungs. This works to...
2. Recruit collapsed (atelectic) alveoli. This makes it so they participate in gas exchange. It also works to...
3. Keep alveoli from collapsing. It keeps alveoli open so the effects of fluid or atelectasis do not cause shunting. This also helps to reduce V/Q mismatching. This also makes it so you have an...
4. Increased PaO2 for a given FiO2. It's a good way of improving oxygenation. 
5. Decreases Cardiac preload and afterload. It reduces the amount of blood returning to the heart, and thereby reduces the amount of blood leaving the heart. In this way, it can help patients who are in heart failure (pulmonary edema) by reducing the amount of work their heart has to do to pump blood through your body. This also means that too much PEEP can be observed by drops in cardiac output, which can be measured by bloodpressure and oxygen saturation (SpO2). 
6. Reduction in tissue injury and inflammation. It prevents the alveoli from constantly opening and closing and thereby inuring them and causing inflammation, which may be associated with the development of ARDS. Studies have shown that it is protective against "ventilator induced lung injury." This is often called volutrauma. Volutrauma was more prevalent back in the days when it was thought that people on ventilators should be on higher tidal volumes, hence the old formula of setting tidal volumes based on 10-15cc/kg ideal body weight. This has now been lowered to 6-8cc/kg ideal body weight in order to prevent volutrauma. 

There are disadvantages of this.

1. Over-distention of alveoli. It causes too much air to stay in the lungs resulting in decreased cardiac output, as would be shown by blood pressure and SpPO2. There are certain instances where you would benefit from higher PEEP, although too much PEEP can lead to over-distention and volutrauma, which may mimic respiratory disease states. So, in such instances, you would want the highest PEEP that doesn't cause over-distention. (Described below is how to accomplish this with a PEEP study). Over-distention results in increased dead space, increased work of breathing, and medical disorders such as ARDS. 
2. Diminished Cardiac Function. As noted, PEEP that is set too high can decrease venous return and cardiac output. This can be measured by complex formulas, although the simplest way is by taking a blood pressure and monitoring pulse oximetry. 
3. Diminished Renal Function. May decrease renal blood flow resulting in diminished urinary output. So, this is another reason to keep PEEP as low as clinically possible, especially when you have a patient in heart or kidney failure. 
4. Increased Intracraneal Pressure. When venous return decreases, intracraneal pressure may increase. This is usually not clinically significant. However, if you have a patient who already has an elevated intracraneal pressure (ICP), such as due to a head trauma, this is something you'll need to watch out for. This is another reason to raise the head of the bed, as this may offset any increase in ICP (the other reason for raising the head is to prevent GERD, which can increase the risk for ventilator associated pneumonia). 

Now that you know about PEEP, along with its benefits and disadvantages, we can now get into how to perform a PEEP study. The purpose here is to determine the perfect PEEP for an individual patient at any given moment in time. Keep in mind here that the ideal PEEP may increase or decrease over time, especially as a patient's medical condition worsens or improves.

Here is the basics of any PEEP study.

1. Increase PEEP by 2-3 cwp every 20 minutes and continue to monitor the patient. You should write down the patients blood pressure and SpO2. If desired, you can also jot down the patients P/F Ratio and static compliance.
2. If static compliance, P/F Ratio &/or SpO2 increase, you know it's working. 
3. Stop when the patient's blood pressure and SpO2 start to drop. Also stop when the P/F Ration is equal or greater than 200. Also stop when the static compliance decreases. 
4. The required PEEP should be set at the PEEP setting used just prior to where the hazards of PEEP were observed. 
5. Do not increase PEEP if systolic BP is less than 90
6. Also, keep mean airway pressure (MAP) less than 15. This is one of the newer markers of too much PEEP. When it starts to drop, this is an early indicator that cardiac output is about to decrease. 
7. Ideally, static complliance should be between 60-100.

I also have a shortcut. Maybe I shouldn't teach you this, but here goes: essentially, based on the wisdom we learned above, all you really need to do is monitor pulse oximetry and blood pressure. If either starts to drop, then you know it's time to lower your PEEP by 2 cwp, which would be your ideal PEEP. This makes it simple. 

The optimal goal of any PEEP study is to find the optimal PEEP to maintain a desired SpO2 and PO2.

If any of my fellow respiratory therapists has anything further to add (any tips), please feel free to share.

(Post originally published on 8/9/08. It has been edited and updated by RT Cave Staff). 

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References:

1. Vincent, Jean Louis, editor, "Intensive Care Medicine: Annual Update 2002," 2002, Springer, pages 302-303
2. Criner, Gerard J., Rodger E. Barnette, Gilbert E. D’Alonzo, editors, “Critical Care Study Guide: Text and Review,” 2nd edition, 2010, Springer
3. Kacmarek, Robert M., James K. Stoller, Albert J. Heuer, “Egan’s Fundamentals of Respiratory Care,” 10th edition, 2013, Elsevier Mosby
4. Saura, Pilar, Lluis Blanch, "Conference Proceedings: How to set Positive End Expiratory Pressure," Respiratory Care, http://www.rcjournal.com/contents/03.02/03.02.0279.cfm, accessed 4/11/17
5. Respiratory Update: "Benefits, Contraindications, Adverse Effects for PEEP/CPAP," http://www.respiratoryupdate.com/members/Contraindications_for_PEEPCPAP.cfm, accessed 4/17/17
6. Valenza, et al., "Positive end-expiratory pressure delays the progression of lung injury during ventilator strategies involving high airway pressure and lung overdistention," Critical Care Medicine, 2003, July, 31 (7), pages 1993-08, https://www.ncbi.nlm.nih.gov/pubmed/12847394, accessed 4/11/17
7. Respiratory Therapy Cave: Respiratory Failure Lexicon
8. Respiratory Therapy Cave: ABG Lexicon

Ventilator Pressures: Static -vs- Plateau

With every ventilator check it is important to measure how much pressure is needed to deliver a tidal volume. There are two different pressures that we typically check: Peak Inspiratory Pressure (PIP), and Static Pressure, also known as plateau pressure (p-plat).

Now to define these two pressures:

• PIP:  This is the pressure at peak inspiration with flow.  
• p-plat:  This is the pressure at peak inspiration after holding your breath.  This is the measure of pressure without flow. 

The best way I can explain these two pressures is by having you take in a deep breath.  Take in a breath as deep as you can.  PIP is the pressure right at the end of inspiration.  Now, hold your breath and relax your chest while still holding your breath.  This is the pressure minus flow.  It is called static or plateau. 

These two pressures are important.  They should both be recorded with each ventilator check.  Now, here is how they can be used.

1.  To monitor resistance and compliance.  

• Both PIP and p-plat go up, or are trending up together, this is probably due to the fact that the patient's lungs are becoming stiff, or less compliant.  In this case, the static compliance may be decreasing.   Efforts should be made to keep the static compliance under 30, such as decreasing tital volume.  This is one reason why low tidal volume strategies are used on patients with ARDS. 
• PIP goes up and p-plat stays the same.  This indicates increased resistance.  It can be measured by taking PIP and subtracting p-plat = resistance.  It may indicate increased resistance, meaning the patient work of breathing (WOB) will be increased, or the patient has to work hard to obtain a desired tital volume.  There are three causes of this:
• Water in the circuit.  Solution is to empty this water (empty water traps)
• Secretions in airway.  Solution is to suction
• Bronchospasm.  Treatment is bronchodilator

Squiggly lines may indicate water in tubing or secretions in airway.

There is another simple method of observing if secretions or water in the circuit are the cause of increased resistance.  When this happens the you will probably observe squiggly lines on the graphics.  When the water is removed from the circuit, or after suctioning, the lines will be normal again.  

A rule of thumb is, if you see squiggly lines, check the circuit for water.  If that doesn't solve the problem, suction should be the next thing to try.  

A recheck of PIP and p-plat after resolving these problems SHOULD result in PIP decreasing, and thus lowering the resistance.  The patient should now be able to breathe easier, or work of breathing should be reduced.

2.  To determine readiness to wean.  Such as, if the patient is requireing more than resistance to obtain adequate ventilation, then the patient is not ready to wean.  Determine resistance by the formula PIP minus p-plat. This is one of the nice things about the servo ventilators, because they have volume support.  In this mode the patient determines his own PS and flow, and therefore you can see how much PS is needed to obtain a tidal volume.  When we want to see if a patient is ready to wean, we turn the patient into volume support.  If the support drawn in by the patient is greater than resistance, the patient is not ready to wean.

Example.  The patient is in assist control or pressure regulated volume support.  Check the PIP and p-plat. Use the formula: PIP minus p-plat = resistance.  PIP =15, P-plat = 10, resistance = 5.  Switch the patient to volume support.  If the pressure is using a PIP of 10, then you know this patient is requiring too much assistance to maintain an adequate tidal volume, and is not ready to wean.  If the patient is requiring only a PS or 5, then he is probably ready to wean.

However, determining readiness to wean involves more than just looking at numbers.

3.   To determine adequate pressure support (PS).  Frequently it occurs that a physician, or a therapist, just makes up a number for PS.  Yet the purpose of PS is to make up for resistance caused by the circuit and endotracheal tube, to make it so it doesn't feel to the patient that he is breathing through a straw.

• PIP minus p-plat = resistance of tubing, endotracheal tube, and airway.  
• Example.  PIP 20 and p-plat 15 = resistance of 5
• 5 should be more than what is needed to make up for the resistance of tubing and ETT, and should make ventilator breaths feel more like normal breathing.  
• Usually this number is somewhere around 5.  However, in patients with lung disease, it may be higher.
• If PS is set at lower than resistance, in this case 5, this results in increased WOB, and this can cause anxiety.  It may result in unnecessary sedation, and failure to wean. 

So, hopefully this information will help you better manage your ventilator patients.  If you find this useful, please let me know.  If you have more tips to add, please feel free to leave a comment below. 

This post was originally published on August 22, 2008 on respiratory therapy cave.  It was updated and edited for accuracy and simplicity by Rick Frea. 

Further reading:

• Medscape, Benjamin D. Singer, Basic Invasive Mechanical Ventilation
• Considerations for readiness to wean
• Acute Respiratory Distress Syndrome
• Respiratory Therapy Formulas and Normal Values

Acute Lung Injury Ventilation Strategy

For patients suspected of being in Adult Respiratory Distress Syndrome (ARDS), you will want to implement the Acute Lung Injury Strategy.

What patients should be included in the ALI Strategy?

• PaO2/ FiO2 > 300
• Bilateral, patchy, difuse infiltratees on x-ray
• Non cardiogenic pulmonary edema
• No evidence of left atrial hypertension

Ventilator set-up:

• Tital Volume: 6-10cc/kg ideal body weight
• Select any mode

Static (Plateau) pressure goal:

• Check after each change in PEEP or Static Pressure
• If greater than 30 decrease Vt by one until Static Pressure less than 30
• If less than 25 and Vt less than 6 ml/kg idw, increase Vt by 1 until static pressure is 25 or Vt is at least 6 ml/kg ibw
• If less than 30 and breath stacking, increase Vt in increments of 1 until Static is greater than 25 or Vt greater than 6ml/kg ibw.

pH Goal: Goal 7.30 to 7.45

A. Acidosis Management: pH 7.15-7.30

• pH less than 7.30 = increase rate until pH greater than 7.30 or pCO2 less than 25
• Maximum set rate is 35

B. Acidosis Management: pH less than 7.15 = increase rate to 35

• If pH remains less than 7.15, Vt may be increased in 1 ml/kg steps until pH greater than 7.15.
• Static Pressure limit of 30 may be exceeded

C. Alkalosis Management: pH greater than 7.45 = decrease rate if possible

Oxygenation Strategy: Goal PO2 55-80 and SpO2 88-95%

A. Lower PEEP higher FiO2 Strategy:

• FiO2 30% = PEEP 5
• FiO2 40% = PEEP 5-8
• FiO2 50% = PEEP 8-10
• FiO2 60% = PEEP 10
• FiO2 70% = PEEP 10-14
• FiO2 80% = PEEP 14
• FiO2 90% = PEEP 14-18
• FiO2 100% = PEEP 18-24

B. Higher PEEP lower FiO2 strategy:

• FiO2 30% = PEEP 5-14
• FiO2 40% = PEEP 14-16
• FiO2 50% = PEEP 16-18
• FiO2 60-80% = PEEP 20-22
• FiO2 90% = PEEP 22
• FiO2 100% = PEEP 22-24

Follow the daily extubation protocol, however add the following adjustments:

A patient meets weening criteria when:

• FiO2 less than 40 and PEEP less than 8
• PEEP and FiO2 are lower than the previous day
• Acceptable spontaneous breathing efforts
• Systolic Blood Pressure greater than 90
• No neuromuscular blocking agents on board

The above information was obtained from ardsnet.org

Ventilator Bundle

Patients used to be left on ventilators too long. If the attending had the day off, the covering doctor was often leery of extubating. The RT on duty wasn't encouraged to "think wean" because there were no protocols. Procedures performed, and sedation, was essentially left to the covering physician, and often varied from patient to patient.

This policy lead to long ventilator stays, increased chance of getting ventilator acquired pneumonia (VAP), and, thus, increased time in hospital, too many poor outcomes, and all this resulting in increased cost to both the patient (or his insurance, or the government) and the hospital.

Studies were done that showed VAP was very high. In fact, every day on the ventilator increased the risk of VAP by 1 percent. Once a patient has VAP, this increases the days on the vent by 4-6 days on average, which increases hospital stays by 4-9 days.

Likewise, fatality rate for VAP is 20-50%, and ultimately costs the hospital an average of $15,000 to $40,000 per patient. Something needed to be done to improve outcomes. The focus was on reducing VAP, and the emphasis was getting all those who cared for the patient on the same page, and thinking the same things.

And if something was missing, or done wrong, others caring for the patient were encouraged to speak up. Studies (like this one) performed showed the following were the best ways to reduce VAP:

1. Good hand washing
2. Ventilator Weaning or extubation Protocols
3. Decrease Ventilator Circuit Contamination:

• use inline suction catheters
• change inline suction catheter every 7 days
• change vent circuit every 30 days (max)

4. Oral Intubations: Studies (as you can see here at Medscapes.com) show that the risk for acquiring VAP is 75% for nasal intubation as opposed to 29% for orally intubated patients.

5. Patient positioning: Keep HOB 30 degrees or greater to decrease risk of aspiration, and lowers diaphragm to improve ventilation, reducing risk of VAP.

6. ETT cuff pressure 20 or greater (a change from what we learned in RT school)

7. Proper Yankauer care, and replace daily. Contamination can potentially cause VAP.

8. Oral intubation: Studies show the best way to intubate patient s is oral intubation, as orally intubated patients had a 34% chance of developing VAP as opposed to 73% of nasally intubated patients.

9. Swabbing the mouth: Studies show swabbing mouth with chlorhexidine gel 3 times a day reduced the risk of VAP from 66% to 29%.

10. Feedings by gastrostromy or jujunostomy: These have the lowest infection rate according to studies. Long term feedings should be done by these methods. Short term feedings should be done by oral gastric tubes as opposed to nasal gastric tubes.

These have all been proven to greatly reduce the risk of VAP. Poor oral care increases the risk of colonization of the mouth, and this can work it's way to the lungs via secretions. An inflated ETT cuff does not prevent germs from reaching the lungs and cause inflammation and pneumonia.

As you can see from the graph above from the MAYO Clinic, from April through December 2003 there were between 6 and 9 cases of VAP per month. Then, almost by miracle, the number dipped to zero, where it has stayed ever since. So what happened?

In January 2004 the MAYO clinic started what is called the ventilator bundle. This is basically an order form that shows the doctor, nurse and RT what needs to be done to prevent VAP The following are the recommendations for a Ventilator Bundle:

• Elevation of head 30-40 degrees unless medically contraindicated


• Continuous removal of subglottic secretions


• Change ventilator circuit no more often than every 48 hours


• Washing of hands before and after contact with each patient


• Daily Sedation Vacation to assess for weaning daily


• Ventilator Weaning or extubation Protocol (always be thinking wean)


• Prophylaxis for DVT


• Prophylaxis for Peptic Ulcer

Here's a copy of our Ventilator Bundle order form from Shoreline Medical. This is a standard sheet that goes in the doctor's orders section for each patient placed on a ventilator:

• Ventilator Protocol Initiated


• Sedation Protocol Initiated


• Peptic Ulcer Protocol Initiated


• DVT Prophylaxis Protocol Initiated


• Glucose Control Protocol Initiated


• Hold Sedation once per day to assess for weanability per ventilator protocol


• Elevate HOB 30-45 degrees unless contraindicated


• Chest X-Ray daily


• ABG daily


• Sputum C&S ASAP after initiation of vent to rule out colonization at time of vent start


• Bronchodilator therapy if indicated (MDI only)


• Dietitian consult if pt. on vent longer than 24 hours to maintain proper nutrition


• Foley catheter


• Oral care TID to QID and prn


• Suction as indicated, or at least once per shift, preferably with inline suction catheter


• Restraints if approved by physician


• ISOPTO tears 1-2 drops as needed

Since the MAYO Clinic initiated its Ventilator Bundle, they have had one reported case of VAP. Likewise, since we initiated ours, we have had only one case of VAP.

It's kind of nice, because it pretty much puts the RNs, doctors and RTs on the same page, and it makes sure that every thing that can possibly be done to improve outcomes, and speed up time from intubation to extubation is done.

About five years ago Shoreline Medical established what it calls the Keystone Committee designed to establish protocols and policy to improve patient care and reduce costs. This committe consists of a champion physician and members from each department within the hospital, including critical care, respiratory therapy, surgery, emergency, administration, and quality assessment.

Quality improvement, and new research, is duscussed on a monthly bases, and the ventilator is updated accordingly. And Ventilator Bundle Core measures are assessed to make sure all procedures are being completed and charted accordingly.

An example of a core measures analysis for the Bundle can be seen in the picture. The goal is to obtain 90% or better in each area, and this is indicated by the green. Green ultimately means the goal has been met.

The areas marked by red indicate the goal has not been met, and something needs to be done to make sure the measure is improved. Ovarall, based on this data, the problem area is oral care. So the team would look at why we are only at 85%.

Is this because the nurse or RT forgot to chart? Was it because the procedure is ordered every 2 hours and this is not possible when the patient needs to sleep? What can be done to correct the problem?

These are all things we think of at our Keystone meetings, and then the bundle is changed if needed.

For examle, our initial bundle changes our practice of lavage and suctioning, and we not have inline suction catheters to reduce the risk of infections. We also give Ventolin MDIs to vent patients instead of breathing treatments.

For us RTs, we are thinking wean as soon as the patient is intubated. Length of time on vents has greatly diminished as well. If we notice the HOB is not elevated 30 degrees, we move it up. If the patient is not receiving feedings, we notify the nurse. Vice versal when it comes to clean suction equipment, and assuring that a sputum sample is obtained to make sure the patient didn't have pneumonia at the time of admission. We work together.

So, ultimately the goal of the Ventilator Bundle is to:

• Reduce VAP


• Reduce time from intubation to extubation


• Reduce costs


• Improve outcomes

Ventilator Bundles work, and one should be initiated at your hospital too.
This topic was also recently discussed at rtmagazine.com

For studies that show what should be done to reduce VAP check out this post at Critical Care Nurse

Ventilator Management Protocol

I am presently working on writing the ideal ventilator management protocol to go with our extubation protocol. Please help me out by adding any ideas or recommendations for the protocol below:

(For a printable copy, click here)

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1. Scope: A Licensed Registered Respiratory Therapist (RRT) who has successfully completed and passed all competencies related to patient assessment and protocols. Certified Respiratory Therapists, respiratory students and assistants may not adjust Mechanical ventilators per protocol.

2. Policy:

A. The Mechanical Ventilator Management Protocol will only be initiated on patients ordered on Vent Management Protocol (VMP), or if the attending physician orders RT Consult on a mechanically ventilated patient.

B. The attending physician may write “discontinue Vent Management Protocol”
(VMP) or discontinue RT Consult at any time.

C. The physician does not need to be notified if:

• a. Weaning FiO2
• b. Increasing FiO2 if not going greater than 50%
• c. Increase in PSV of 5 or less to maintain adequate tidal volume
• d. Changing in and out of volume support

D. The physician will be notified when:

• a. The respiratory therapist wishes to initiate VMP on a patient who is not Currently on the protocol
• b. If the patient’s condition is deteriorating.
• c. The respiratory therapist is unable to determine appropriate therapy.
• d. If the FiO2 is greater than 60% and PaO2 less than 60mmHg or SpO2 less than 90% with

5cmH20 PEEP.

e. When pre-determined therapy limits are reached, i.e. FiO2, Vt, PEEP, RR, etc.

f. When PEEP greater than 5 is indicated.

g. If PEEP greater than5 has been approved, and now PEEP less than 8 is indicated.

h. A RR greater than 30 or less than 8 is indicated

i. A VT greater than 10 ml/kg ideal body weight or less than 6 ml/kg is indicated.

j. If VT or PEEP is indicated that results in PIP greater than or = 40 or plateau pressure greater than 30.

k. Weaning success or failure

l. Increasing FiO2 above 50% is indicated to maintain sats

m. Change in PSV greater than 5 cmH20 is made

n. A change in tidal volume is made

o. A change in respiratory rate is made

E. For continuous monitoring of ABG values, an arterial line should be introduced, and/or the use of non-invasive monitoring (SpO2 & EtCO2)should be employed. Non-invasive monitoring is preferred.

F. Modify ventilator settings as indicated to maintain target values.

G. Assure the non-invasive oxygen saturation (SpO2) and end tidal CO2 (EtCO2) values correlate with current ABGs.

H. If rate of greater than 30 is indicated, consider sedation prior to calling physician.

I. Maximum PIP is determined by increasing PEEP in increments of
1cmH20. Stop increasing when BP, HR, SpO2 drop, or PaO2/Fio2 Ratio = or less than 200. If the PaO2/FiO2 ratio increases you know PEEP therapy is working.

J. When considering the adjustment of FiO2, hemoglobin should be checked to ensure the absence of anemia. Hemodynamic data should be checked to ensure adequate circulation.

3. Ventilator Management Protocol: The following are guidelines for use in stabilization and management of the patient on mechanical ventilation:

A. The following values will be maintained, unless otherwise ordered by physician.

• a. Ph: 7.35 to 7.45
• b. PaCO2: 35 to 45 mmHg (EtCO2: 30 to 50 mmHg), unless the patients “usual” PaCO2 is chronically elevated.
• c. PaO2: 60 to 100 mmHg (SpO2 greater than 90%)
• d. In patients with COPD, adjust parameters to the patient’s “normal” values

B. Obtain ABG or non-invasive oxygen saturation (SpO2) and end tidal CO2

C. Adjust the ventilator settings to correct abnormal ABG and/or SpO2 and EtCO2 values.

a. Abnormal PaCO2 greater than 45 mmHg (EtCO2) values:

• 1. Increase rate in increments of 2 to obtain acceptable values.
• 2. Increase Tidal Volume by increments of 50ml to obtain acceptable values

b. Abnormal PaCO2 less than 35 mmHg (EtCO2) values:

• 1. Decrease rate in increments of 2 to obtain acceptable values.
• 2. Decrease Tidal Volume by increments of 50ml to obtain acceptable values.

c. Abnormal PaO2/SpO2 values:

• 1. PaO2 less than 60 mmHg or SpO2 less than90%, increase FiO2 in increments of 05% to obtain acceptable values.
• 2. For hypoxia (Sa02 less than 92%)requiring greater than 60% FiO2, increase PEEP in steps of 1 cmH20 at a time to PEEP max (specific Dr. order required)
• 5. With PEEP = or greater than 5 & PaO2 greater than 100 mmHg or Spo2 greater than 95%, decrease FiO2 in increments of 05% to obtain acceptable values.
• 6. If the SpO2 or PaO2 is not adequate after any weaning attempt of the Fi02, increase the Fi02 to the previous setting. Continue weaning the Fi02 as tolerated by patient.

D. Non-invasive monitoring or ABG criteria is not the absolute control for maintaining Ventilatory support. Sudden changes in cardiovascular status, respiratory rate, and color may mandate a change in ventilator parameters.

E. Once patient is stabilized, and once the problem that resulted in the need for Ventilatory support has been resolved, the patient should be continuously monitored for indications for weaning (See Ventilator Weaning Protocol).

4. Documentation:

A. Initial assessment

• a. An RT assessment will be performed within 15-45 minutes from start of ventilation.
• b. Assessment will include evaluation of the patient’s general appearance, blood pressure, heart rate, breath sounds, ventilating pressures, volumes and ABGs.
• c. Assessments may also include additional data, when available, such as EtCO2 and hemodynamic data.
• d. Ventilator checks will be completed every two hours and documented accordingly. Checks will include ventilator settings, pressures, and essential alarms
• e. Cuff pressure will be checked once per shift, and a minimum cuff pressure of 20 cwp will be maintained in order to minimize VAP.
• f. All therapy will be documented in computer charting.

B. Re-assessments

• a. Regular assessment of general appearance, vital signs, breath sounds and Hemodynamic stability should be evaluated prior to and during any ventilator adjustment.
• B. Adjustments of the patient’s therapy will be determined objectively by changes in the monitored parameters.

5. References:

1. Mechanical Ventilator Protocol, Retrieved from: http://rtcorner.net/rt_forms.htm
and http://rtcorner.net/rt_forms.htm

2. Mechanical Ventilator Protocols, Retrieved from:
http://www.aarc.org/resources/protocol_resources/documents/general_vent.pdf
3. CTICU Weaning Protocol, retrieved from: http://www.dhmc.org/webpage.cfm?site_id=2&org_id=116&morg_id=0&sec_id=0&gsec_id=5560&item_id=7386

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For a related article, check out "Ventilator Weaning Protocols" by Bill Croft @ rtmagazine.com

Ventilator Delerium should not be overlooked

I don't think this matters so much on day shift, but I think on the night shift we RTs and RNs and doctors when writing orders ought to have more consideration for the amount of sleep our patients get, especially patients in the critical care on a ventilator.

There's this thing called Ventilator Narcosis (Delirium) that I think is way underdiagnosed. In fact, I bet it hardly ever gets diagnosed.

According to the August, 2007, issue of Chest, Ventilator Delirium effects 85% of patients receiving mechanical ventilation, resulting in , "and has been linked to prolonged length of stay, reintubation, higher mortality, and higher costs of care."

Delirium, or cognitive decline, often effects elderly patients who are on narcotics or benzodiazepines and left in a state of coma (or "suspended animation") for lengthy periods of time, thus resulting in a poor quality of sleep.

Or, poor lighting coupled with the above and continued patient agitation resulting in lack of adequate sleep often causes a patient (particularly the elderly) to enter into a state of cognitive decline. This happens even in elderly patients who are in otherwise good physical condition.

Likewise, "recommendations by professional societies have established the importance of delirium monitoring and recommended it as standard practice in ICUs all over the world."

Roger Striker at RTMagazine.com provides a more cons ice definition:

"Delirium, as defined by the DSM-IV, requires an acute disturbance of consciousness with reduced clarity or awareness of the environment (eg, an inability to focus or to sustain or shift attention) and either (1) a new cognitive change (eg, deficits in memory or orientation, or a language disturbance) or (2) a new perceptual disturbance (eg, hallucinations or misinterpretations).2 Delirium frequently develops over hours or days, and fluctuates over time.

One of the major contributing factors is believed to be poorly dosed, or too much, narcotics for the age of the patient. Many experts who study ventilator delirium note that most doctors dose narcotics the same for most patients, when the dose should be adjusted for age and size -- particularly in the elderly.

Along with too much, or poorly dosed narcotics, we hospital staffers add to this problem by constantly irritating the patient.

Think about it though. You would go nuts too if the lights were on in your bedroom all night long, and every two hours someone came in to brush your teeth, and every hour between that someone came in to roll you over, or wipe your bottom, or break the circuit of the vent to give you a breathing treatment or squirt in an MDI, or dump water out of the circuit, or insert a new IV.

There have been studies done on this, and the result to every one I've read the experts conclude that the lights need to be out for at least 8 consecutive hours a night, and interfering with the patient needs to be kept to a complete minimum in order for that patient to get a good nights sleep to prevent Ventilator Narcosis.

However, at Shoreline Medical, we have a protocol that calls for 2 puffs of Ventolin every 6 hours, and a good mouth cleaning every 2 hours, and shifting the patient from side to side every hour. The result here is that the patient never gets more than one hour of consecutive sleep.

Since the average sleep cycle lasts 1.5 hours, one can assume that ventilated patient rarely if ever gets through a cycle. And, the result of lack of enough REM sleep is psychosis.

What has me most concerned is brushing the teeth every 2 hours. I understand that a good mouth cleaning is a great way to prevent ventilator acquired pneumonia, but I think there comes a time you use an amount of common sense and just let the patient miss a few of these mouth cleanings so he can get some sleep.

Some RNs I've talked to agree with me, and they ignore the protocol at night. Some, however (those who do everything by the book), never miss a mouth cleaning. To these individuals, the reasoning "I have to do it because it's protocol," or "I have to do it because the doctor ordered it," supersedes common sense.

I understand that rotating the patient often is a great way to prevent blood clots from forming, although I don't see why a little night time common sense can't prevail to allow the patient to sleep.

I understand why the overhead light needs to be on most of the day to so we can see the patient from the nurses station, but putting on the nightlight for six hours during the night shift is a great way to allow the patient to fall asleep and get some REM.

Thankfully most patients don't remember being on a ventilator anyway, even if they appear to be awake and appropriate at the moment. I have asked many patients a day or two after extubation if they remember anything, and a majority of them say, "No. I remember nothing."

Riker notes, "Most trauma patients have no recall of their ICU stay, but slightly more than one third do remember these events; 88 percent of the time, they have fantasies or hallucinations about being in prison and trying to escape."

So, the next time you are taking care of a patient on mechanical ventilation, ventilator psychosis or delirium or cognitive decline should be something for you to consider discussing with the attending physician.

The five levels of a good ventilator protocol

I have found from my studies that there are five different levels of a ventilator protocol.

Level 1: Ventilator set-up
Level 2: Ventilator management
Level 3: Ventilator weaning
Level 4: Ventilator extubation
Level 5: Other

So, the first level of a true ventilator protocol is the set-up. Pretty much here you need a standard range of settings to be adjusted for each particular patient, and each particular disease state.

For example, we have a standard tidal volume range of 6-10cc/kg ideal body weight. If a patient presents with an acute lung injury (ALI), we start at the low end. Otherwise, we adjust this range depending on the patient.

Basically, a vent set-up protocol has in it anything you need to set up a ventilator: RR, VT, PEEP, FiO2, and mode.

Whether you start at 40% FiO2 like we do and adjust accordingly to maintain an SpO2 of 92% (or an appropriate sat for the patient), or whether you start at 100% and work down depends on your particular institution.

What else do you need to set-up a vent. Well, you need more than your basic ventilator settings. You also might want some sedation, an NG, soft restraints if needed, etc.

So, level one is the set-up level. We have this in our protocol that is already enacted (see ventilator set-up link above).

Level 2 is a ventilator management protocol. This, I am afraid to admit, is something that is missing from our ventilator protocol.

Ventilator management would require allowing the RT to make changes in the original ventilator settings without directly talking with the physician. This we cannot do at Shoreline.

I will go into more detail on a ventilator management protocol that I would like to see enacted here in a later post.

Level two would include something like the following:

1. If CO2 is greater 45, increase rate. If ABG still not normalized, increase VT in increments of 50cc
2. If CO2 is less than 35, decrease the rate. If ABG still not normalized, decrease the VT in increments of 50cc.
3. FiO2 should be adjusted to maintain an SpO2 of 92% or to maintain a value normal for patient or condition, or as directed by physician.
4. If FiO2 at 100% and PO2 less than 60, PEEP should be implemented. I suppose here you might add a PEEP study as part of the protocol.

I'm not writing a protocol here, just providing some examples of what might be seen in a ventilator management protocol.

Level 3 would include anything that would allow you to wean a patient off the above mentioned settings once the patient is normalized. Here you would need to have some type of criteria for weaning, of which we do at Shoreline (check out this link to see the basic weaning criteria).

Now, our weaning criteria does not include everything that is mentioned in that link, but the basic idea is there: The patient is not on any vasopressors, the HR has to be within a particular range, the BP cannot be >20% of patient normal, the condition that placed the patient on the vent must be resolved, the patient must be awake and alert, secretions must be thin and minimal to name a few.

The patient also must require less than 40% FiO2 and have an PEEP of 5 or less while maintaining an appropriate SpO2.

Whatever weaning criteria your particular hospital has will basically depend on the physicians at your institution, or the requirements recommended by your hospital committee.

So, once the patient meats weaning criteria, you have the ability to wean a patient's rate and tidal volume to encourage a patient to breath on his or her own.

Now, we do not have the ability to decrease rate or VT, but we do have the ability to put a patient in automode. So, kind of in a roundabout way, we do have a weaning protocol. Still, it would be nice to be able to adjust the VT and RT, which would allow me the ability to adjust the patients minute ventilation even while a patient is in VS mode.

Because, ideally, the minute ventilation the patient is maintaining on the ventilator should be equal to the minute ventilation he would have if he were off the ventilator. Sometimes, however, especially on the Servo 300A, this minute ventilation is not the same as what is dialed into the machine, and must be adjusted by the RT -- but this doesn't always happen.

Anyway, once the patient is in volume support, the weaning process begins. Yet still, at my hospital, it is up to the doctor and not the RT to make the next step. Thus, we do not have a true ventilator weaning protocol.

While we cannot wean RR and VT, we do have the ability to wean FiO2 to maintain an appropriate SpO2.

Thus, we kind of have a weaning protocol, but we aren't quite there all the way yet. This, however, is something we will be working on in the coming weeks -- this and a true ventilator management protocol.

Level 5 is a ventilator extubation protocol. We do have this, and you can check out the link above to see a good extubation protocol. This affords us RTs the ability to assess the patient daily for weaning criteria, and perform weaning parameters if the patient meets criteria.

Once a patient meets criteria, we have the ability to do a spontaneous breathing trial (SBT). Once the patient passes that, we do weaning parameters again, draw ABGs, and call for order to extubate.

Of course the patient could fail, and this would require the patient to stay on the vent another day. However, just because a patient fails a daily weaning trial does not mean the physician, RT and RN should stop thinking about weaning -- that should never stop.

In fact, the weaning process should start as soon as the patient is placed on the ventilator. And that is why I think it would work out to the benefit of the patient if all hospitals afforded RTs with the ability to do at least the first four levels of a ventilator protocol.

Level 5 would pretty much depend on what kind of a hospital you have, and whether your doctors have faith in your RT department to be independent in the care of certain types ventilated patients, such as ARDS, ALI, Sepsis, trauma, neuro, cardiac, etc.

For example, an ARDS/ALI ventilator protocol would be included here. This would allow the RT to adjust the ventilator strategy according to the type of patient on the vent. Being a smaller hospital that transfers most of these patients, I doubt our doctors would approve of this type of protocol for my particular hospital.

However, for the larger hospital in the Bigger Cities, I know the ARDS/ALI protocol that I wrote about in the link above is implemented and working well.

Still, I would be flabbergasted if it were incorporated here at Shoreline. But, even though it's not, I think it's important for us RTs here to have an understanding of such a protocol, as we too can participate in making recommendations on the patient's behalf to the physician -- or at the very least have an understanding what the doctor is up to.

We don't need a cardiac, neuro or trauma protocol here as most of those patients are shipped to whatever larger hospital will take them. Maybe that will change some day, but currently it's been a challenge to draw in those types of physicians (mainly because if we get one, he will have to be on call for himself 24-7, which is not a good selling point).

Well, there you have it: the five levels of a ventilator protocol. Not counting level five, we here at Shoreline are about 70% of the way to a full fledged ventilator protocol. What percent of the way is your hospital?

An RT department that has all of steps 1-4 would be at 100%. An RT department that has all five levels would be at 125%. I suppose if you have all of levels 1-4 and a cardiac, and a neuro, and an ALI/ARDS, and whatever other protocols there are for ventilators out there, you might get all the way up to 200+%.

That would be really cool.

If we had that, and a full fledged RT Treatment protocol that allowed us to only do
breathing treatments on those patient's who need them, this RT would be in RT Heaven.

Ventilator protocol: Setting up pt. on ventilator; and some information about EtCO2 monitoring

As I've been writing about the past few posts, we have a so-so Ventilator protocol here at Shoreline, and we are currently in the process of updating it.

Just for the record here, the ventilators we use are the Servo 300A and the Servo i.

While the majority of the protocol is actually an extubation protocol, we also have the ability to wean FiO2 to maintain an SpO2 of 92%. Which is nice, because before we used to have to sit on an SpO2 of 100 on a specified FiO2 all night long. Now I can wean it down as low as necessary.

This has got to be better for the patient, considering the hazards of oxygen therapy.

So, basically, when setting up a ventilator, we can pretty much determine the most appropriate respitatory rate, FiO2 and tidal volume for the patient based on the protocol, as opposed to just making up numbers.

Here are the initial vent settings per protocol:

1. FiO2: 40%, and increase to main SpO2 >92% (or as specified by physician).
2. VT: 6-10 ml/kg IBW (for Acute Lung Injury or ARDS use 6 ml/kg IBW)
3. PRVC: 10-14 BPM


4. PEEP: 5


5. ABG within 30 minutes post set-up


6. Automode: per RT discretion


7. Maintain cuff pressure >20


8. Suction and send sputum to lab


9. Perform oral care Q2 hours


10. elevate head of bed 40 degrees

There's a little more than just ventilator settings there, so allow me to explain.

First, our doctor who is championing the protocol has decided that lower tidal volumes are safer for patients than the 10-15cc/kg IBW that is taught in RT school. Actually, people with normal lungs may use 10-15cc/kg IBW, but it's better to be on the safe side with lower tidal volumes.

Likewise, studies have shown lower tidal volumes to be equally effective ventilation.

As per another hospital's ventilator protocol: "Recent literature has shown tidal volumes in the range of 7-10 cc/kg to be effective in ventilation while reducing the risk of barotrauma."

So, the going trend is to start low and increase as indicated, based on ETCO2 (see below) and SpO2 or ABG.

PEEP of 5 is a good place to start, and increase as indicated or as directed by a physician. I discussed PEEP studies a few days ago.

Along with an ABG, an X-Ray should be completed within 30 minutes. Soft wrist restraints as needed, Ativan as needed, NG, etc. are also included in the protocol.

While this is not a ventilator weaning protocol per se, the ability of the RT to turn on automode allows us to basically switch the patient over from PRVC to volume support. In VS, the patient determines his own flow and pressure support.

For the most part, in the aspect, we RTs are allowed to change modes, so long as the mode we choose to change it to is VS. The funny thing is, I think a lot of doctors have little understanding of automode, as even while the patient may have been in Volume Support for three days, some of our doctors continue to order for rate and tidal volume changes thinking that's what the patient will get.

Now this is fine, so long as they understand the changes are in order to maintain a minute ventilation, as opposed to guaranteeing the preset rate and tidal volume.

It can be safe to say that once the patient switches himself to volume support, he has taken the first step in the weaning process.

Basically, the pressure support in volume suport mode can be measured by subtracting static pressure from peak pressure. If PIP is 20 and static is 15, then the pressure support the patient is drawing in is 5, which is actually a good number. Anything under 10 is good. If a patient is sucking in more than 10, then you may be safe to assume the patient is not weanable.

Automode is nice for the patient, because as he wakes up, he is able to actually control the vent, instead of the vent controlling the patient. This was a big selling point for us in choosing to purchase the Servo vents.

When I explain the ventilator to nurses and patients, I tell them that it is "state of the art life support technology, and it actually has a brain that senses when the patient is ready to breath on his own."

And, when the patient stops breathing on his own, the vent will automatically switch back to the PRVC mode. And then back to VS after the patient takes three consecutive spontaneous breaths.

I wouldn't always turn the automode on. If the patient had a cardiac event, or if the patient is not breathing effectively on his own, I would keep the patient in PRVC.

Basically, once the patient is in automode, and stays there, the weaning process is started. The initial vent settings are assuring the patient maintains the desired minute ventilation, but otherwise determining his own settings.

While in school we were taught that the cuff pressure should always be maintained at less than 20 to make sure the circulation to the arteries are not cut off. However, with new research, it has been learned that most patients are intubated for such a short period of time now, that this is less of a concern.

As I've written about before on this blog, the average stay on a ventilator has significanly decreased since the advent of microprosessor ventilators that allow the patient to control the vent instead of the other way around.

So, now we want the cuff pressure to be >20. The reason here is we want to prevent VAP. Also, to prevent Ventilator Acquired Pneumonia (VAP), we make sure that we clean the oral cavity as often as possible. Our protocol recommends Q2 hours. Usually this job is shared between RTs and RNs.

Then, so we can prove later that the patient had pneumonia prior to being placed on the vent, or to prove that we caused it later on, we obtain a sputum as soon as possible and send it to the lab.

Also, we want to make sure the head of bed is elevated to protect the airway, and prevent aspiration, which is another VAP preventative measure.

Ultimately, however, "the guidelines listed above should be considered a starting point for most patients. Adjustments to rate, tidal volume, or inspiratory time should be made according to disease process or as changes in the patient's condition warrants. Closely monitor BP, HR, RR, EtCO2 (as needed), SpO2, and breath sounds for changes in patient status."

Shorter inspiratory times and longer expiratory times may be indicated for some asthma and COPD patients to prevent air trapping.

EtCO2 should be monitored on all ventilator patients. A normal EtCO2 is 40, however the EtCO2 should be coordinated with the ABG so it can be monitored instead of doing ABGs.

There are some conditions that may alter EtCO2 and cause it to read lower than the actual ABG due to shunting. These include:

1. Asthma


2. COPD


3. Severe Pneumonia


4. ARDS


5. Chest trauma


6. pulmonary embolism


7. decreased cardiac output

This is progress based on the latest studies. If you guys think our data is wrong, or if you have new information to add here, please feel free to respond. We RT are continuously trying to stay up to date, or to stay ahead of the curve.

ALI, ARDS Ventilator Strategy

Note: An error has occurred in this post, and parts of it are presently unavailable. I am aware of the problem and will correct is in the next few days. Rick Feb. 8, 2010

Being a smaller hospital, we RT here at Shoreline don't have many opportunities to take care of patients with Acute Lung Injuries (ALI) or Acute Respiratory Distress Syndrome (ARDS). However, we do on occasion. When this happens, it pays to be up to date on the best methods of caring for these patients.

After much research, we found that the larger hospital in this area has one of the better ALI or ARDS Ventilator strategies.

The gaol with ALI or ARDS is to ventilate at the lowest pressure possible. And, while our ventilator protocol calls for tidal volumes of 6-10cc/kg IBW, the target tidal volume for these processes is 6 cc/kg IBW.

Since pressures is a major issue with ALI & ARDS, it is critical to monitor ventilating pressures, and often the tidal volume must be adjusted based on the ventilating pressures. And, instead of basing the tidal volume on peak inspiratory pressure (PIP), plateau pressure (p-plat) should be used.

Why is this? PIP is a measurement of pressure while a patient is still inhaling, and it measures flow, secretions, and water in the circuit. Static, however, is a measure of pressure once a patient inhales and relaxes. It is a true measure of compliance.

With this in mind, this is why we use p-plat to determine static compliance, which should be in the ranges of 60-100. When the static compliance is <60,>100, then you know you have increased compliance, as you will see with emphasema.

This in mind, here is an abreviated version of an ALI or ARDS Ventilator Strategy, which is ultimately lung protective ventilation:

A. Ideal VT = 6 ml/kg IBW
B. Oxygenation target:

1. PaO2 55-80
2. SpO2 88-95%
3. If PsO2 greater than 80 or sustained SpO2 greater than 95%, decrease FiO2 by 0.1
4. If PaO2
5. Physician will order changes in PEEP as indicated.

C. pH Goal: 7.30-7.45

1. greater than 7.45: Decrease Rate
2. less than 7.30: increase rate
3. If rate greater than 35, or CO2 >
4. >

D. Plateau Pressure: Dr. to select target pressure

1. If greater than 30 & due to VT, decrease VT by 50cc Q1 hour until p-plat >
2. If >

E. Patients ventilated this way are usually tachypneic. Respiratory rate alone cannot be used as a measure of discomfort in these patients. Some patients require increased sedation to tolerate lung protection ventilation.

F. A patient can still meet lung protective criteria even while on low FiO2s, so lung compliance should not be a criteria for determining use of this protocol. DO NOT MISS AN OPPORTUNITY TO USE LUNG PROTECTIVE VENTILATION BECAUSE THE PATIENT'S LUNG INJURY DOESN'T LOOK THAT BAD.

G. Pt's on lung protective ventilation often are hypercapneic and acidemic. So do not treat abnormal CO2 or pH unless there are advers cardiac effects. Tolerate pH as low as 7.15 and consider the use of Bicarbonate, if necessary, to treat more severe levels of acidosis in order to allow for lung protective ventilation.

H. FiO2 should be maintained as low as possible, and a PEEP study should be completed if ordered by physician (see how to do a PEEP Study post tomorrow).

I. FiO2 can have consequences to the patients lungs, and therefore should be lowered to 60% before decreasing PEEP, so long as there are no complications to high PEEP develop.

Keep in mind I wrote this post not because we do this often at Shoreline, but because when we do have to take care of an ARDS or ALI patient, I am up to date on the latest stategies for taking care of these patients.

For more information, check out ARDS.net.

Ventilator extubation Protocol

Perhaps one of the best ways of preventing Ventilator-Associated Pneumonia is by creating and implementing a ventilator extubation protocol. This assures that caregivers begin thinking extubation almost immediately as soon as a person is intubated. Such a protocol my include the following:

1.  Weaning Screen.  In the past physicians wrote orders for weaning parameters, which include respiratory rate, tidal volume (Vt), forced Vital Capacity (FVC), and negative inspiratory pressure (NIF). Most modern protocols call for screening the patient for the following.

• Fio2 less than 40% 
• PEEP less than 5 cwp (oxygenation status stable)
• Heart Rate greater than 50 and less than 120 (heart rate stable)
• Temperature less than 100.5 (higher means something is not resolved)
• SpO2 greater than 90% (or specified by physician)
• Systolic blood pressure greater than 90
• Minimal or no sedation
• No signs of respiratory distress
• Able to follow commands
• Adequate cough
• Plateau pressure less than 30 cwp (higher may indicate ARDS)
• Patient's underlying condition resolved

Please note that these are general recommendations. Some common sense must come into play too, as you must consider the patient. For instance, some patients with chronic lung diseases will have a normal SpO2 less than 90%. So, this must be accounted for when considering whether or not to begin a spontaneous breathing trial (SBT). 

2.  Spontaneous Breathing Trial.  Here is where you place the patient in a spontaneous mode to see how he will do. Some protocols will call for placing the patient in CPAP alone, although others may also involve some pressure support (PS) to accommodate for airway resistance caused by the endotracheal tube (ETT) and the ventilator tubing. Whichever method is used is fine so long as you are consistent. One hospital decided on the following formula:

• 7.5 ETT or less: Set the patient on CPAP of 5 and PS of 5
• 8.0 ETT or greater: Set the patient on CPAP of 5 and PS of 0

Basically, you will want to eliminate the resistance of the tubing, although you don't want to set the patient up to fail either. For instance, if you set the PS at 10, the patient has a greater chance of passing the weaning screen, thereby looking good enough to extubate. Yet then require re-intubation later on. 

A good way of knowing where to set the PS if you don't have a protocol is to check the Peak Airway Pressure (PAP) and the Plateau Pressure (P-plat) prior to performing the SBT

Say the Peak pressure for a patient is 20 and the static pressure is 15. The difference between the two is the resistance. Pressure Support, therefore, should be set to equal resistance, which in this case would be five.

If, in our attempt to wean the patient, we turn the pressure support down to zero, then, some experts contend, we are setting the patient up to fail. Therefore, pressure support should never be turned below resistance.

So, that's kind of the thinking on whether or not to use pressure support. Whatever your hospital uses is fine so long as it is consistent. If one therapist is using pressure support and another is not, the values will not be consistent, and therefor will not be very useful.

An SBT entails using a mode like PS and CP, and then seeing how the patient does for about five minutes. Then a second weaning screen should be performed.

• Respiratory Rate less than 30
• SpO2 90% or less (or specified by physician)
• Heart rate less than 120
• Blood pressure within 20% of baseline
• RSBI (f/vt) less than 100
• No apnea
• No diaphoresis
• No anxiety
• No respiratory distress

Does the patient pass these? If no, then place the patient back on the original settings and notify the physician that patient is not ready to be weaned. If yes, then perform weaning parameters. 

• NIF equal to or greater than 20 cwp
• FVC less than 10 ml/kg
• VT of greater than 5 ml/kg (or appropriate for patient)
• Respiratory rate less than 30
• Minute Ventilation greater than 5 and less than 15
• RSBI (f/vt) less than 100

If the patient fails, then place patient back on original settings. 

3.  Extubation.  If the patient passes, then you continue the SBT for 30 minutes to a couple hours. Then you redo the screen. If the patient continues to do well, you can draw and ABG and discuss with the patient's nurse and doctor to see if the patient can be extubated. 

Every ventilator extubation protocol will have its differences from this one, although they should all be with the same goal of speeding time of intubation to extubation, and the overall goal is to prevent VAP and other ventilator associated events (VAE).

Note: This post was edited on July 5, 2016, by John A. Bottrell