NURS 418 - Mechanical Ventilation

21-100%

mechanical ventilation delivers warm, humidified oxygen between _____% FiO2

tidal volume (Vt)

volume of air exchanged during a normal breath

vital capacity (VC)

volume of air exhaled with maximal effort after maximal inspiration

fraction of inspired oxygen (FiO2)

the concentration of oxygen delivered to the patient

functional residual capacity

the volume of air remaining in the lungs after maximal exhalation

1. apnea or impending inability to breathe

2. ventilatory failure

3. severe hypoxia

4. respiratory muscle fatigue

5. respiratory rate greater than 35 or less than 8-10

indications for mechanical ventilation (5)

pH < 7.35 and PaCO2 > 50 mmHg

a pH _____ and PaCO2 _____ indicates ventilatory failure and requires mechanical ventilation

> 50%

a patient that requires FiO2 _____ to maintain adequate oxygenation indicates severe hypoxia and requires mechanical ventilation

< 60 mmHg

a PaO2 _____ on oxygen indicates severe hypoxia and requires mechanical ventilation

non-invasive negative pressure ventilation

type of mechanical ventilation: involves the use of chambers that encase the chest or body and surround it with intermittent sub-atmospheric pressure

non-invasive negative pressure ventilation

type of mechanical ventilation: used for patients with chronic respiratory failure who requires assisted ventilation for short periods

1. spinal cord injuries

2. Guillain-Barre'

3. ALS

conditions requiring non-invasive negative pressure ventilation (3)

non-invasive negative pressure ventilation

type of mechanical ventilation: iron lung, chest vest, body wrap, bodysuits

non-invasive positive pressure ventilation (NIPPV)

type of mechanical ventilation: used short-term in weaning, after extubation, or in acute respiratory insufficiency that is expected to resolve quickly

non-invasive positive pressure ventilation (NIPPV)

type of mechanical ventilation: used in long-term management of sleep apnea

non-invasive positive pressure ventilation (NIPPV)

type of mechanical ventilation: CPAP, BiPAP

1. CPAP

2. BiPAP

types of non-invasive positive pressure ventilation (2)

CPAP

type of non-invasive positive pressure ventilation: maintains continuous level of positive pressure-constant flow

CPAP

type of non-invasive positive pressure ventilation: similar to PEEP, but applied continuously (PEEP is on exhalation)

BiPAP

type of non-invasive positive pressure ventilation: involves two levels of positive airway pressure (inspiratory positive airway pressure (IPAP) and expiratory positive airway pressure (EPAP))

invasive positive pressure ventilation

type of mechanical ventilation: requires artificial airway such as endotracheal tube or tracheostomy

invasive positive pressure ventilation

type of mechanical ventilation: breaths are delivered until pre-set volume or pressure is reached, expiration is passive

1. volume ventilation

2. pressure ventilation

types of invasive positive pressure ventilation (2)

volume ventilation

type of invasive positive pressure ventilation: ventilator is controlled by a pre-set tidal volume and will deliver the set volume regardless of changes in lung compliance or resistance. the tidal volume is consistent from breath to breath, but the airway pressures needed to deliver the tidal volumes will vary

volume ventilation

type of invasive positive pressure ventilation: the tidal volume is set and airway pressures are measured

pressure ventilation

type of invasive positive pressure ventilation: ventilator delivers air until preset inspiratory airway pressure is present. the tidal volume delivered to the patient will vary based on the pressure selected and compliance and resistance factors of the lungs

pressure ventilation

type of invasive positive pressure ventilation: the airway pressure is set and tidal volumes are measured

tidal volume varies according to patient's pulmonary system. hypoventilation and respiratory acidosis may occur in patients with increased resistance to flow or decreased compliance

what is a disadvantage of pressure ventilation?

controlled mandatory ventilation (CMV)

ventilator mode: delivers a preset volume at regular intervals regardless of the patient's inspiratory effort

controlled mandatory ventilation (CMV)

ventilator mode: used in patients with no respiratory effort, including high C-spine injuries, end-stage degenerative neuro disease, and chemical paralysis

assist-control mandatory ventilation (AC)

ventilator mode: delivers a preset volume or pressure at a preset rate, but also delivers the preset volume when a spontaneous breath is initiated by the patient

assist-control mandatory ventilation (AC)

ventilator mode: the ventilator delivers a preset tidal volume at a preset respiratory rate. when the patient initiates a spontaneous breath, the ventilator delivers the preset tidal volume as well

assist-control mandatory ventilation (AC)

ventilator mode: may cause respiratory alkalosis in patients with a high respiratory rate (hyperventilation)

synchronized intermittent mandatory ventilation (SIMV)

ventilator mode: delivers a preset volume or pressure at a preset rate, but allows the patient to breathe at their own respiratory rate and volume between respirations

synchronized intermittent mandatory ventilation (SIMV)

ventilator mode: the ventilator delivers a preset tidal volume at a preset respiratory rate. in between the ventilator-delivered breaths, the patient can breathe spontaneously and achieve whatever tidal volume they can achieve

synchronized intermittent mandatory ventilation (SIMV)

ventilator mode: prevents respiratory muscle weakness

pressure support ventilation (PSV)

ventilator mode: delivers a preset amount of pressure during inspiration (the duration of the spontaneous breath)

pressure support ventilation (PSV)

ventilator mode: a preset pressure is applied to the airway ONLY during inspiration. the patient MUST be able to initiate the breath. as the patient starts a breath, the ventilator senses the spontaneous respiratory effort and supplies the patient with positive pressure

pressure support ventilation (PSV)

ventilator mode: the patient determines their own inspiratory length, tidal volume, and respiratory rate (no tidal volume or rate is set on the ventilator)

pressure support ventilation (PSV)

ventilator mode: augments the patient's spontaneous respiration and decreases the work of breathing

positive end expiratory pressure (PEEP)

ventilator mode: delivers a preset amount of pressure during exhalation

positive end expiratory pressure (PEEP)

ventilator mode: facilitates oxygenation by increasing surface area in the alveoli for gas exchange to occur and preventing airway collapse

positive end expiratory pressure (PEEP)

ventilator mode: maximizes the number of alveoli available for oxygen exchange (alveolar recruitment)

positive end expiratory pressure (PEEP)

ventilator mode: allows for oxygenation to occur with less FiO2

5 cm of H20

physiological PEEP

5 cm

a PEEP higher than _____ results in decreased cardiac output

higher levels of PEEP results in decreased venous return, decreasing cardiac output

how does PEEP effect cardiac output?

1. decreased cardiac output due to decreased venous return

2. alveolar barotrauma

3. may stimulate renin-angiotensin release and later decrease renal function due to decreased renal flow

complications of PEEP (3)

rate/frequency (f)

ventilator setting: the amount of breaths delivered to the patient each minute

tidal volume (Vt)

ventilator setting: the volume of air that is delivered to the patient with each breath

6-10 mL/kg

on the ventilator, tidal volume is usually set at _____

fraction of inspired oxygen (FiO2)

ventilator setting: the concentration of oxygen delivered to the patient

the lowest % to achieve a PaO2 of at least 60%

on the ventilator, FiO2 is usually set at _____

positive end expiratory pressure (PEEP)

ventilator setting: positive pressure delivered to the patient during expiration to prevent closure of the alveoli so gas exchange can occur

5-10

*avoid increasing r/t barotrauma and decreased cardiac output

on the ventilator, PEEP is usually set at _____

pressure support (PS)

ventilator setting: positive pressure delivered to the patient during inhalation when taking spontaneous breaths

5-10

on the ventilator, pressure support (PS) is usually set at _____

minute ventilation (VE)

ventilator setting: the amount of air delivered into the lungs in one minute

VE = TV x RR

minute ventilation (VE) equation

peak inspiratory pressure (PIP)

ventilator setting: the maximum pressure present in the lungs during each inspiration

positive expiratory end pressure (PEEP)

ventilator setting: a good indicator of how well the lungs can maintain alveolar expansion and avoid alveolar collapse

plateau pressure (Pplat)

ventilator setting: gives us information about lung compliance or how easy or hard it is for the lungs to expand/contract in response to pressure changes

1. disconnection

2. leak

3. ETT down the right mainstem bronchus

4. accidental extubation

low pressure ventilator alarms signal (4)

1. patient biting ETT

2. occlusion by secretions

3. bronchospasm

high pressure ventilator alarms signal

impaired cerebral blood flow

*when PEEP is too high, cardiac output decreases, therefore there is inadequate blood flow to the brain

neurologic system complications occur as a result of mechanical ventilation r/t _____

neuromuscular blocking agents

used to provide more effective synchrony with the ventilator thereby increasing oxygenation

weaning

the process of reducing ventilator support and resuming spontaneous ventilation

PaO2/FiO2 > 150-400

PaO2/FiO2 that indicates adequate oxygenation and signals that the patient is ready to begin weaning

SpO2 ≥ 90%

SpO2 that indicates adequate oxygenation and signals that the patient is ready to begin weaning

PEEP ≤ 5-8 cm H20

PEEP that indicates adequate oxygenation and signals that the patient is ready to begin weaning

FiO2 ≤ 40-50%

FiO2 that indicates adequate oxygenation and signals that the patient is ready to begin weaning

pH ≥ 7.25

pH that indicates adequate oxygenation and signals that the patient is ready to begin weaning

Hgb ≥ 7-10 mg/dL

Hgb level that signals that the patient is ready to begin weaning

T ≤ 100.4

core temperature that signals that the patient is ready to begin weaning

RR > 8 and < 35

RR that signals that the patient is ready to begin weaning

TV ≥ 10 mL/kg

tidal volume that signals that the patient is ready to begin weaning

RSBI < 105

rapid shallow breathing index (RSBI) that signals that the patient is ready to begin weaning

NIF > -20

negative inspiratory force (NIF) that signals that the patient is ready to begin weaning

CROP > 13

compliance, respiratory rate, oxygenation, maximal inspiratory pressure index (CROP) that signals that the patient is ready to begin weaning

1. use of pressure support or CPAP is common

2. T-piece with O2 for one hour

3. one-daily trial of spontaneous breathing

4. monitor SpO2, HR, RR, and BP

5. return patient to the ventilator if the patient is in acute distress

process of weaning (5)

≥ 30

head of bed elevation _____ degrees reduces the frequency and risk for nosocomial pneumonia compared to a supine position

thromboprophylaxis

the use of _____ is effective for preventing DVT

peptic ulcer disease (PUD) prophylaxis

the use of _____ reduces the risk of upper gastrointestinal bleeding

sedative

daily interruption of _____ drug infusions decreases the duration of mechanical ventilation and length of stay in the ICU

≤ 110 mg/dL

intensive insulin therapy to maintain blood glucose _____ reduces morbidity and mortality among critically ill patients

trials of spontaneous breathing

daily screening of the respiratory function followed by _____ can reduce the duration of mechanical ventilation, decrease complications and costs of ICU care

2-4 hours

mouth care should be performed every _____ with chlorhexidine solution for patients on a ventilator