Can anyone think of a topic to research on NIMV ??? give me something specific.. i am finding hard to find something that is not already researched??? anything that you might think it will work but has not yet been researched??? please help! thanks
I'll just list some of my ideas on the topic, maybe something will "click"...
Basically the patients need mostly ventilatory support, or general mean airway support. For instance COPDers and asthmatics benefit from some auto-peep counterbalancing, and also some ventilatory assistance. And the benefit must balance the "price" of having a mask (hopefully just nasal) attached. As the degree of pulsus paradoxus is a good indication of the presence of auto-peep AND the pleth signal of the pulse oximeter (especially that displays waveforms) is a clinically reliable indicator of pulsus pardoxus (Chest articles) how about a study in which either the MD specifies the EPAP vs. EPAP set by whatever it takes to obliterate the pulsus paradoxus seen on the pleth? (and PS set to get same VT?)
There are some new nasal cannula-like devices from Inomed and Viaysis. Could these be used such that double-limbed circuit vents (i.e. LTV, Drager with NIV option, etc.) would be more tolerated. Having a double limb circuit affixed to a full face mask and all strapped seems to put alot of pressure on the face.
I have noticed that patients with pulmonary hypertension (usually given nebulized Flolan) can be a bit "atelectasis intolerant" after extubation. They seem to benefit from robust Bipap (i.e. 20/10) beyond that which would seem necessary during a SBT while on the vent pre-extubation. I think this is because the further drop in FRC causes the PVR to then go up---and splinting open the airways helps to keep PVR less. If you have enough patients with high PVR getting open heart surgery, routinely put some on NIV post-op and some not. ?
For some reason many MD's order the Spontaneous/Timed (S/T) mode on Bipap. And many RT's think it's of some benefit. IMO all this does is eradicate the apnea alarm potential of the low pressure alarm. How about a bench study in which some inspr. model can mimmick apnea AND have the same resistance of various sized patients whom would be apneic. How much VT does a Timed Pressure Support breath (at various IPAP-EPAP differences) give a patient when they go apneic. The hypothesis could be that no effective ventilation occurs during such a situation and all it does it eradicate the apnea alarm potential.
The only justification for S/T I've heard is that, when the mask is leaking so much that patient triggering doesn't occur ( the alarm would sound?--but maybe gets ignored?) that at least the timed cycling would perhaps help ventilate. (Sloppy non-invasive APRV). One could also create such a situation on a bench model and see if the timed mode combined wiht a big leak actually does augment ventilation.
As the nasal mask is far better tolerated, what if some nasal "care" was provided via nasal warmed saline irrigation (patient blows nose and coughs up). Would such a practice help nasal NIV effectiveness? (Could also do before and after nightly NIV use for OSA?).
What I remember being somewhat established already in studies (mostly CCM) is that the neb should be near the patient mask, the O2 should go back by the machine, and nasal masks are better tolerated---yet full face masks do better for the worst patients if tolerated.
I'm a new therapist, and get a lot of orders for Bipap with a full face mask. We were taught in school that a full face mask requires an NG tube, which patients frequently do not have. I usually document on my vent sheet that I suggested one when I do the initial set up.
Does anyone else run into this? Is an NG really necessary? Many patients never get one, and they do fine.
nimv in our hospie is new too. We use the conventional ventilator (bird 7200) with mask and rubber strap to do this mode on cpap with p.s. After connection we see almost immediate increase in saturation. NGT sometimes is causing leak (but we know the need for it) and have you noticed the deformation of the face? (due to tight mask seal)?
ric mandanas jrThis message has been edited. Last edited by: ric crt,
We use non-invasive ventilation routinely here as a means of preventing intubation. We call it foreplay because it is only a prelude to the inevitable. I beleive the problem is merely an equipment issue. We are using servo 900C on PSV with a full face mask strapped to the face. IMO you should only use a machine designed for NIV and the servo is certainly not. How about a study comparing effectiveness of NIV using BiPAP vs. ventilator with outcome measurements being WOB indices and intubation rates? If THere is already one out there that you know if can you tell me?
As for the need for an NGT........without question regardless of the leak it imposes! I have seen a patient arrest after a BiPAP inflated her belly and obliterated her respiratory reserve. Remember that BiPAP is DESIGNED to operate with a leak. Another reason ventilators should not be used for NIV.
Before discounting the use of a ventilator for noninvasive ventilatory support you may want to try using a ventilator with either a fixed, user set or automatic leak compensation mechanism and with faster triggering. The Servo 900C has no mechanism for compensating for leaks and studies have shown that the trigger delay is signficant in comparison with other ventilators. I would guess that the combination of a lack of leak compensation and significant trigger delay might induce a dys-synchrony between your patient and ventilatory support.
All Newport ventilators offer a form of leak compensation and trigger faster than the Servo 900C.
All my best,
Director of Clinical Education
Newport MEdical Instruments
1.800.4513111 ext 218
You may find some interesting topics in the current isssue (June) of CHEST. We just put links to it in our News section.
Speaking of using a standard vent for NIV....while hopefully the vent has leak compensation and other NIV friendly options (i.e. LTV, Drager E4 upgrade and the Newport mentioned above), what about the problem of affixing a double limbed circuit to the face of the patient? I find that often the weight and/or torque of the doulbe limbed circuit is a problem. Has anyone tried using a standard vent with the Innomed nasal interface? It is like one BIG nasal cannula. The "Y" would sit down by the lap and the continuous leak could be flushed out by the little holes up by the nose?
When an NG tube is used with a full face mask on bipap, typically what size NG tube is used? Is it connected to low suction of just left to vent to the atmosphere? What are the popular full face masks being used with bipap and how do you get a good seal around the mask with the NG tube? Thanks for you replies.
In response to Ms. Miller, Dir. of clinical education for Newport ventilators, All new generation ventilators (Maquet Servo-I, P.B., Drager and Viasys)all have some type of leak compensation. Comparing her new ventilator to the 30 plus year old Servo 900 is not a fair comparision. All new ventilators now have a refresh rate between 500 and 2000 times per second.