mechanical ventilation

what “is” non-invasive ventilation?

positive pressure ventilation administered via nasal cannula or face mask → nasal cannula, simple mask, non-rebreather, high flow nasal cannula, CPAP/BiPAP

what are the rates for non-invasive ventilation things?

• nasal cannula: 1-6 lpm

• simple mask: 6-10 lpm

• non-rebreather: 10-15 lpm

• high flow nasal cannula: 15-60 lpm

what is CPAP?

non-invasive machine used to provide continuous expiratory positive airway pressure (EPAP) → often utilized for obstructive sleep apnea and/or hypoxemia; good for patients with airway collapse

what is BiPAP?

non-invasive machine used to provide BOTH inspiratory and expiratory positive airway pressure (IPAP & EPAP) → often utilized for obstructive sleep apnea, hypercapnea, and intubation prevention

what does IPAP and EPAP allow for?

IPAP: allows for ventilation, EPAP: allows for oxygenation → inspiratory pressure will always be higher than expiratory pressure

what are the benefits of non-invasive ventilation?

has the ability to provide similar effects to that of invasive ventilation without risks of an artificial airway → patient is able to oxygenate, ventilate, relax respiratory muscles and WOB, preserve glottic function and reduce risk of aspiration

what is important to know about patients on CPAP/BiPAP?

they cannot be restrained as they need the ability to pull off mask if needing to vomit or else they can aspirate

what metabolic signs are shown in someone who is nearing invasive ventilation?

metabolic/respiratory acidosis (pH < 7.35), hypercapnea (CO2 > 50), hypoxemia (PaO2 < 60 on ABG), elevated lactate (sign of tissue/organ hypoxia)

what are the two types of invasive ventilation?

endotracheal tube & tracheostomy tube

what is PEEP?

also called EPAP → positive pressure applied at the end of each exhalation to keep the airway & alveoli from collapsing, it makes sure the pressure in the lungs is greater than atmospheric pressure → makes it easy to facilitate oxygen into the body BUT increases intrathoracic pressure which decreases preload which decreases cardiac output

what is tidal volume?

amount of air moved through the lungs during each inhalation and exhalation → depends on ideal body weight, usually a guess

what is FIO2?

fraction of inspired oxygen → the concentration of oxygen provided in the gas mixture during a breath cycle; room air is 21% and the max is 100%

what “is” volume?

the amount of air moved through the lungs during inhalation and exhalation, helps facilitate ventilation → 5-15 mL/kg of air is considered normal

what “is” pressure?

keeps airway open for alveolar recruitment and to allow for larger volumes received, helps facilitate oxygenation

characteristics of volume control mode on a ventilator?

provider determines tidal volume and respiratory rate, settings ensure the same amount of volume will be given for any breath including spontaneous ones, pressure is the variable in this mode as the vent will deliver ordered volume regardless of amount of pressure it takes → commonly used in patients who don’t spontaneously breathe

characteristics of pressure control mode on a ventilator?

provider determines the inspiratory pressure IPAP and respiratory rate, settings ensure the same pressure is provided for all breaths taken, tidal volume is the variable in this mode as the vent will deliver the ordered pressure regardless of the amount of volume in the breath → often used in those with acute lung injuries/decreased lung compliance and providers want to prevent further lung damage or barotrauma

characteristics of pressure regulated volume control mode on a ventilator?

vent will attempt to deliver a set tidal volume at the lowest possible pressure, this mode adapts to every breath with the IPAP adjusting up or down to meet the desired tidal volume, pressure is the variable, there are pressure limits set to prevent too high of IPAP (if limit is met before targeted tidal volume is achieved, breath will terminate) → lung protective mode often used in patients w ARDS

characteristics of spontaneous intermittent mandatory ventilation mode on a ventilator?

vent will deliver a set respiratory rate with a designated amount of tidal volume while also allowing unrestricted spontaneous breaths, spontaneous breath can be of any volume and the mandatory breath will adjust to synchronize around the patient’s effort → often used to help wean patients off of a vent; if pt isn’t spontaneously breathing, this mode is the same as volume control mode BUT different in that it allows for spontaneous breaths of any size or volume or pressure

characteristics of pressure support mode on a ventilator?

patient initiates spontaneous breaths and tidal volumes, each breath is supported by a set inspiratory and expiratory pressure → used for vent weaning before tube removal

why will the high peak inspiratory pressure alarm go off?

if the patient is gagging, coughing, biting on the tube, the patient is trying to breathe over the vent too much and is causing dis-synchrony, patient has a mucus plug and/or needs to be suctioned, lung compliance worsening (pneumothorax, ARDS, bronchospasm)

what are some nursing interventions for the high peak inspiratory pressure alarm going off?

have respiratory therapist place a bite block, adjust the patient’s sedation so they are more synchronous with the vent or have provider adjust the settings, provide timely pulmonary hygiene and/or suctioning, education on s/s of worsening conditions and communicate w provider

why will the low minute volume alarm go off?

the ET tube or tracheostomy cuff has deflated which allows air to escape around it, there is a leak in the circuit (cap is open or the circuit became disconnected), there are chest wounds or drains allowing air to escape, the ET cuff has migrated above the vocal cords

what are some nursing interventions for the low minute volume alarm going off?

notify RT who can reinsert air into the cuff, trace lines and reattach the connections (usually will hear air coming from the area), alert provider of any air escaping into chest tubes and palpate for crepitus, notify provider and advocate for CXR to observe tube positioning

what are some complications associated with being on a ventilator?

VAP (ventilatory associated PNA) from prolonged intubation, aspiration, poor pulmonary hygiene, barotrauma (extreme lung expansion and difficulty returning to original size), respiratory muscle weakness, overall deconditioning

what are the two main settings that facilitate ventilation and the exchange of oxygen and CO2 (also two things that most commonly change/fluctuate)?

RR and tidal volume

what would the provider possibly do if the patient has a high CO2 level?

increase RR first and then increase tidal volume breath size → more breath, more opportunity to ventilate or exchange CO2

what are the two main settings that affect oxygenation (air being carried through bloodstream through alveoli, binding to hemoglobin in RBCs and going to tissues)?

pressure and FIO2

when to adjust IPAP (in BiPAP)?

think CO2/ventilation → if pt has high CO2 (respiratory acidosis, hypoventilation) you want to increase IPAP as increasing IPAP increases the pressure difference between IPAP and EPAP which allows for bigger tidal volumes, more ventilation, and better CO2 removal

when to adjust EPAP (in BiPAP) or PEEP (in vent)?

think O2/oxygenation → if pt is hypoxic, want to increase EPAP/PEEP to prevent alveolar collapse to improve surface area for gas exchange and raise oxygen levels

how to prevent intubation?

reposition patient, have them cough, use incentive spirometer, tripoding position

what do we want to keep our PaO2 above?

around 80-85 → want O2 sat around 90 as too much oxygen can cause oxygen toxicity (don’t want PaO2 too high)

what is PEEP relating to collapsing alveoli?

pushing walls open for good gas exchange to keep them from collapsing when exhaling → not a natural thing so patients need to be sedated; “fighting the vent”

how to prevent VAP?

pantoprazole (prevent acid reflux), constant suctioning of sub-glottic cuff area to prevent mouth gunk from going into lungs, position HOB to 30 degrees