Questions on Mechanical Ventilators - page 2

by floridarose

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Hello:) I need help with answering the questions for my vent training certification. I'll appreciate any help you can give. Please if you know of any websites that can help a newbie, pls send it my way. I have experience with... Read More


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    LTV 950 & LTV 1150 ventilator circuits,
    The circuits for these ventilators are disposable. Soaking them in water and soap may cause them to improperly monitor the patient leading to bad consequences. These circuits should be the responsibility of the agency supplying the ventilator which also should have a Respiratory Therapist on call for your questions.

    The question posted about cleaning the circut probably pertains to a nondisposable circuit. Again, you should follow the recommendations of the manufacturer and the DME company supplying that specific ventilator and not a generic statement which does not give details for the make and model.

    Complications of high volume or pressure set in pediatrics or infants on mechanical ventilators are all of the above except


    High volume and high pressure can lead to overdistention and pneumothorax.

    Oxygen toxicity is caused by prolonged exposure to a high FiO2 usually > 0.50.

    PNA is a consequence of mechanical ventilation and measures should be taken to prevent it like aspiration precautions and being mindful where you lay the circuit when not connected to the child.

    What is the mandatory mode for setting pediatrics or infants on mechanical ventilation?


    The answer for this question will vary the size of the child and the disease process. Infants will normally be on a pressure setting but that can also be a very difficult mode to monitor in home care which can do harm while trying to also prevent it. Strict alarm adherence must be in place for this mode...as with all ventilator setting.
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    Quote from FrankM
    Hi. I live in the Los Angeles area. I was wondering if you know where I can take a good vent training. Maybe if you can give me the name of the company that you took the training with. seems like a really good training they gave you. thanks
    The best way to get sound training is to contact the clinical rep through the ventilators manufacturer. Then have an RT department conduct an inservice for your agency along with the clinical rep. One can not learn very much about ventilators and the theory behind them. Six hours are definitly not enough. Some states are trying to recommend that Paramedics get at least 16 - 24 hours to operate the very simplistic transport ventilators which doesn't even include training for one like the LTV 1200. Our RTs spend 6 hours in training with the clinical rep each time they get a new ventilator and that is with over 2 years of a Respiratory Therapy degree as their base. Our ICU RNs will then get at least 1 hour for an inservice on each new ventilator.

    Also, Pulmonetics (LTV ventilators) have their manuals and a great video on their website for viewing.
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    I agree with you, that oxygen toxicity does not fit. How can you get oxygen toxicity if you ventilate your pt with high volumes or pressures on an FiO2 of .21? High pressures and volumes do release inflamitory mediators in the lungs, and I would assume therefore increase the susceptibility of pneumonia, much the same way that asthmatics and COPDers are more susceptible to lung infections.
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    i need help with 3 questins concerning a ventilator.
    1) In the SIMV mode, all patient breaths are delivered by the ventilator.
    true or false

    2) The amount of pressure needed to keep the lungs from totally collapsing after exhalation is peak inspiratory pressure (PIP).
    true or false

    3) The secondary low-pressure alarm may alert the caregiver that the tubing may be kinked.
    true or false
  5. 0
    Quote from 912smith
    i need help with 3 questins concerning a ventilator.
    1) In the SIMV mode, all patient breaths are delivered by the ventilator.
    true or false

    2) The amount of pressure needed to keep the lungs from totally collapsing after exhalation is peak inspiratory pressure (PIP).
    true or false

    3) The secondary low-pressure alarm may alert the caregiver that the tubing may be kinked.
    true or false
    How about you tell us what you think the answers and why, then we can discuss. Sorry, I'm not going to give you answers without any discussion.
  6. 0
    I could be wrong, but in regard to:
    i need help with 3 questins concerning a ventilator.
    1) In the SIMV mode, all patient breaths are delivered by the ventilator.
    true or false

    2) The amount of pressure needed to keep the lungs from totally collapsing after exhalation is peak inspiratory pressure (PIP).
    true or false

    3) The secondary low-pressure alarm may alert the caregiver that the tubing may be kinked.
    true or false

    1. simv stands for synchronized intermittent mandatory ventilation. It has a minimal rate, say simv12. This minimal rate will be delivered by the ventilator, no matter what (think of it as a back-up rate). Now.......let us say the patient decides to take a breath on their own......the machine synchronizes with the patient breath request, and gives the volume of air per its settings (perhaps a tidal volume of 700cc or whatever). It is synchronized. It is intermittent because it gives the breaths at the minimal rate AND the patient's own breath request rate (this prevents 'air hunger' if you will, prevents anxiety that you can not breathe on your own, and will help you with the breath via delivering the volume). It is mandatory, because once that patient initiates the breath, it is going to give that mandatory volume, and mandatory minimal back-up rate.

    2. peak inspiratory pressure is probably not what you are looking for to prevent lung collapse. Peak inspiratory pressure varies (ards or wet lungs, bronchoconstriction, obstrucive process, whatever).......you dont want it to get too high cause you could cause a pneumothorax, in uncuffed cases, possible abdominal distention, etc., ntm trauma to the lungs. You dont want your mean airway pressures to be high over prolonged periods of time, and the PIP is part of that equation.

    Instead, I believe you are looking for PEEP--positive end expiratory pressure. This can be 5cm h2o or whatever the pulmonologist and RT think is optimal based on serial abg's, clinical condition, etc etc., but frequently it is somewhere between 5 to 10. This positive end expiratory pressure maintains airway pressure in the lungs, preventing the alveoli from collapsing, thus allowing maximal time for respiratory exchange (which includes the diffusion of gases, oxygen and carbon dioxide in particular), and thus providing optimal clinical condition.


    3. 'low pressure' alarms are usually a result of low pressure......thus, a LEAK......the gases are escaping somehow, thus reading low pressure. If the tube was KINKED, the pressures should be HIGH, cause the ventilator attempts to cycle, and there is an obstruction to the gas flow, causing the pressures to increase, setting off high pressure alarms.


    that is my take on it anyway. hope it helps. and, i am not an expert, so be forewarned. i am just a nurse. Really you should ask your respiratory therapist.

    yes, i did read that blue textbook 20years ago (egans respiratory care), and i have worked with lots of ventilators, but i never had a single inservice. just self-taught stuff.
  7. 0
    also, just to be clear.......simv does not have to deliver the 700cc in all settings.......assist control, also labeled CMV (albeit nearly incorrectly and confusingly, as that stands for controlled mandatory ventilation, wherein you are not supposed to be allowed to take your own breaths......it can be used for sedated and paralyzed cases), WILL deliver that exact volume, however...........

    so, simv can allow the patient to take their own breaths between the backup rate, with NO guaranteed volume delivered by the machine.............

    CMV, which should be labeled AC for assist control, DOES give that prescribed volume with every patient breath request.........

    SIMV allows for a lower minute averaged mean airway pressure for the patient........which is something you want.........because when the patient breathes, it doesnt have to push 700cc, and give all that pressure to achieve that 700cc volume.

    CMV/AC WILL always give that 700cc volume, thereby producing higher averaged mean airway pressures.


    sorry about that...........

    it is just that simv on some ventilators can do some tricky stuff.......you CAN make it do certain stuff..........

    But, in the traditional, old-fashioned sense.......SIMV all by itself will only give the 12breaths of 700ml, allow the patient to breath on their own more if they wish, without giving them 700ml, but instead just allowing however much they can inhale on their own (300ml or whatever).

    hope that is clear as mud.



    ventilators have become most complex nowadays, being both volume controlled, pressure controlled, bilevel controlled, cpap controlled, allow talking with cuff deflation, etc etc etc............
  8. 0
    I am not sure I track you on the lower minute averaged pressure always being something you want? You have other options such as pressure controlled ventilation and "hybrid" modalities such as VC+ (PB 840) or PRVC (Servo-i) that will work with AC. SIMV has many pitfalls that must be appreciated. Increased work of breathing can occur with SIMV among other problems. The pros and cons of each mode must be considered; however, SIMV is not a mode I would often consider for a variety of patients.
  9. 0
    Quote from 912smith
    i need help with 3 questins concerning a ventilator.
    1) In the SIMV mode, all patient breaths are delivered by the ventilator.
    true or false
    This question can either be a trick question on an RT exam or a poorly written question on a nursing quiz.
  10. 0
    Quote from GreyGull
    This question can either be a trick question on an RT exam or a poorly written question on a nursing quiz.
    probly a question on RT exam of some sorts. I wouldnt necessarily say it is a trick question (it wants you to think it thru), but it could definitely be written better.


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