Term
| what is an iron lung (drinker ventilator)? |
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Definition
| a negative pressure generator (big syringe that pts go in) |
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Term
| what is a cuirass ventilator? |
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Definition
| an iron lung that is fitted to just go over the chest |
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Term
| what are the two types of positive pressure ventilators? |
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Definition
| volume and pressure ventilators (the name tells you what the endpoint of the push is, ie. a volume ventilator will stop at certain volume) |
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Term
| what is the problem with volume ventilators? |
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Definition
| the pressure varies and can be too high/low |
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Term
| what is the problem with pressure ventilators? |
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Definition
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Term
| what is CMV? what are the 2 modes? |
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Definition
| continuous mechanical ventilation of which there are two modes: assist control (breathing rate is constant, but if the pt creates a little negative pressure - the machine instantly provides another breath, *make sure you check what the pt is blowing at, not what the machine is set at*) and control (pt has no control of breathing rate - no one uses this) |
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Term
| what is synchronized intermittent mechanical ventilation (IMV)? |
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Definition
| this is used for getting pts off assist control ventilation and still consists of regulated machine breaths, but in between those, the pt is on their own and can take a breath of whatever volume they want. over time the pt can be *weaned* off the machine breaths. |
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Term
| what is the principle behind CPAP? |
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Definition
| the bigger the gradient between your mouth and the alveoli, the bigger the breath. CPAP creates a higher gradient in pts mouths, allowing pts unable to create normal gradients in their lungs (COPD pts) to take normal breaths. (there is no pushing in CPAP) |
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Term
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Definition
| CPAP with a negative expiratory pressure, b/c some pts have a harder time breathing out against CPAP |
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Term
| what is pressure support? |
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Definition
| another weaning mode ventilation machine that some think is better than SIMV. the machine "pushes" air into a pts lungs up to a certain pressure, and then anything thing past that the pt can top off. the main problem with this is the volume may vary. (hydration can decrease lung compliance etc) |
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Term
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Definition
| a *better weaning mode, where the pt triggers a breath and the machine pushes to a preset volume which the pt can then top off |
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Term
| what is the progression of mechanical ventilation types for a pt coming off support? |
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Definition
| control assist -> weaning mode like volume support -> CPAP |
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Term
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Definition
| positive end expiratory pressure, which keeps more air than usual in your lungs at the end of a breath. this can *help oxygenate pts. |
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Term
| which is longer, inspiration or expiration? |
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Definition
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Term
| how does PEEP help with air trapping? |
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Definition
| if a pt has a diseased lobe and a healthy lobe, most of the air during inspiration goes to the healthy lobe and only a little air may go to the diseased lobe at the end of inspiration. PEEP allows inspiration to last longer and keep the diseased alveoli oxygenated (recruit latent alveoli) and keep the lung from collapsing. |
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Term
| what is an inverse I/E ratio? |
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Definition
| making inspiration last longer, like w/PEEP in order to "recruit latent alveoli" |
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Term
| what is the limiting factor w/inverse I/E ratio? |
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Definition
| a longer inspiration causes more positive pressure which inhibits venous return (increased BP) |
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