ventilator module

Question 1

what is negative-pressure ventilators

Answer 1

external ventilators that decerase atmospheric pressure surrounding the thorax to initiate inspiration.
i.e. iron lung

Question 2

what is positive pressure ventilation

Answer 2

-common in acute care
-forces air into lungs via ETT of trach
-can use non invasive masks i.e. bipap

Question 3

4 phases of ventilation

Answer 3

1. change from exhalation to inhalation
2. inspiration
   3.change from inspiration to exhalation
   4.exhalation

Question 4

4 different ventilator variables

Answer 4

-volume
-pressure
-flow
-time

Question 5

what is the “trigger”

Answer 5

the phase variable that initiates the change from exhalation to inspiration
-can be pressure triggered or flow triggered, breaths can also be triggered

Question 6

what is the “limit” or “target”

Answer 6

the variable that maintains inspiration
-can be pressure-limited, flow-limited, or volume-limited

Question 7

what is the “cycle”

Answer 7

the variable that ends inspiration

Question 8

what is the “baseline”

Answer 8

the variable that is controlled during exhalation
-the pressure is always adjusted to this variable, the pt exhales to a certain pressure that is set on the vent at 0 (atmospheric pressure) or above atmospheric pressure (PEEP)

Question 9

what are volume-cycled ventilators?

Answer 9

designed to deliver a breath until a preset volume is delivered

Question 10

what are pressure-cycled ventilators

Answer 10

delivers a breath until a preset volume is delivered

Question 11

what are flow-cycled ventilators

Answer 11

delivers a breath until a preset inspiratory flow rate is achieved

Question 12

what are time-cycled ventilators

Answer 12

delivers a breath over a preset time interval

Question 13

what is assist control (AC) ventilation?

Answer 13

-ventilator provides a full ventilation for the client, takes over the work of breathing
-tidal volume and vent rate is preset
-vent will deliver preset # of breaths if the client does not initiate a breath
-if client triggers the vent, it will deliver a preset tidal volume (CAN CAUSE HYPERVENTILATION->RESP ALKALOSIS, client may require sedation to dec resp rate/triggers)

Question 14

what is synchronized intermittent mandatory ventilation (SIMV)

Answer 14

-tidal vol and vent rate are preset
-between vent-assisted breaths, allows client to breathe spontaneously at their own rate and tidal volume
-used as regular mode of vent or mode to wean client off
-if weaning # of SIMV resps is gradually dec as client triggers inc (can cause inc breathing workload->resp fatigue)

Question 15

what is positive end-expiratory pressure (PEEP)

Answer 15

-baseline (preset) pressure that prevents the client from exhaling past that pressure during exhalation. elevated baseline adds positive airway pressure to mechanically deliver breaths
-improves oxygenation by enhancing gas exchange and preventing atelectasis, keeps airway open at the end of exhalation preventing alveolar collapse->inc # alveoli available for ventilation

Question 16

normal PEEP value

Answer 16

5-15cm H2O
-normal physiologic glottis closure occurs at 5, with artificial airway glottis remaining open and normal PEEP does not occur

Question 17

what is continuous positive airway pressure (CPAP)

Answer 17

-application of positive pressure during spontaneous breaths
-invasive or non-invasive
-non-invasive can be used to deliver positive pressure during breaths to delay intubation while tx is initiated, also used for OSA

Question 18

what is pressure support ventilation (PSV)

Answer 18

-positive pressure delivered to the client on inspiration
-alleviates WOB which inc oxygenation and ventilation
-may allow for lower o2 conc to be used
-helps avoid atelectasis
-can be used during weaning, during weaning PSV is decreased

Question 19

normal pressure support ventilation (PSV) value

Answer 19

5-20cm H2O
baseline PSV (5cm) is used to overcome resistance/workload imposed by the artificial airway

Question 20

what is FiO2 and normal value

Answer 20

conc of oxygen delivered to the client
-goal is maintain PaO2 of >60mmHg using FiO2 of 40% or less

Question 21

what is tidal volume and normal value

Answer 21

the volume of air the client received with each breath
-5-8ml/kg of ideal body weight

Question 22

what is I:E ratio

Answer 22

comparison of inspiratory to expiratory time

Question 23

what is peak airway pressure and normal value

Answer 23

maximal pressure level achieved during a breath
<40cm H2O

Question 24

what is sensitivity

Answer 24

determines the inspiratory effort required to trigger a mechanical ventilated breath

Question 25

physiologic complications of mechanical ventilation

Answer 25

-barotrauma -pneumothorax -subcut emphysema -malnutrition -muscular deconditioning -hypotension -alterations in cardiac function -fluid retention -hemodynamic compromise -oxygen toxicity -aspiration -gastro ulcer -client-ventilatory asynchrony -ventilator dependence -ventilator-associated pneumonia (VAP)

Question 26

what is ventilator-associated pneumonia (VAP)

Answer 26

pneumonia acquired during ventilation -direct and indirect factors promote development of VAP -bypasses normal lung defense mechanisms creating possibility of contamination of lower airway within 24h - vents, nebs, IPPB, nasogastric tubes, enteral feeds, and meds also promote pneumonia

Question 27

2 most important nursing interventions for vented patients

Answer 27

-respiratory assessment -ABG analysis

Question 28

what is included in resp assessment of vented pt

Answer 28

-ETT location -observe/palpate subcut emphysema -review vent settings/alarms -promote airway clearance/suction PRN

Question 29

effective airway clearance for vented pt

Answer 29

resp assessment Q2-4h to identify issues such as secretions that need to be suctioned -humified o2 liquefies secretions -bronchodilators help dilate brochioles

Question 30

nutrition for vented patients

Answer 30

enteral feed are preferred if GI system is intact -start initial feeds slowly, observed for intolerance (dehydration, diarrhea) -monitor BG -rate is increased when tolerated, high protein is required for resp muscle strength

Question 31

eye care for vented patients

Answer 31

-may not have blink reflex -instill lubricating drops/ointment -apply eye shields -apply moisture chamber -scleral edema can be reduced by elevating HOB

Question 32

mouth care for vented patients

Answer 32

-intact mucosa prevents infection -increased comfort, dec thirst, and preserved mucosa

Question 33

preventing trauma and infection in vented patients

Answer 33

-position tubing so its not pulling or kinked -check cuff for pressure and leaks -observe colour and odor of sputum -elevate HOB to prevent aspiration and pneumonia -PPI for ulcer prophylaxis

Question 34

psych care for vented patients

Answer 34

-psychological distress can be caused by sleep deprivation, sensory overstimulation, pain, fear, inability to communicate, medications -vent can precipitate psychological dependence -support family

Question 35

medications used in vented patients

Answer 35

-used to minimize discomfort, reduce anxiety and agitation, facilitate vent and improve oxygenation -commonly used ones are analgesics, sedatives and neuromuscular blocking agents (i.e. pavulon, norcuron) used in conjunction with a sedative or anxiolytic agent

Question 36

pain medication for vented patient

Answer 36

-administered if client has pain-producing illness or surgery

Question 37

immobility and vented patients

Answer 37

-prevent skin breakdown -prevent atelectasis -DVT prevention

Question 38

neuromuscular blocking agents and vented patients

Answer 38

-can result in skeletal muscle weakness -paralysis is monitored using peripheral nerve stimulation

Question 39

preventing ventilator-associated pneumonia (VAP)

Answer 39

-elevated HOB 30 deg -temporarily interrupt sedation and conduct spontaneous breathing trial each day -adequate pain control -CAM assessment -using oral tubes vs nasal tubes for trachs or G tubes -provide oral care -hand hygiene

Question 40

what is weaning

Answer 40

the gradual withdrawal of mechanical ventilator support and the reestablishment of the client's spontaneous breathing. -only begins after client has been stabilized and reason for needing the vent has been corrected

Question 41

how do you wean a client off the vent

Answer 41

-evaluate clients LOC, physiologic and hemodynamic stability, adequacy of oxygenation and ventilation, spontaneous breathing capability, resp rate and pattern -position client upright, suction airway if needed -provide reassurance -assess immediately before and frequently during for signs of intolerance

Question 42

methods to wean a client off the vent

Answer 42

1. T-piece trials 2. synchronous intermittent mandatory ventilation (SIMV) 3. pressure support ventilation (PSV)

Question 43

what is bucking/fighting the vent

Answer 43

the client's respiratory effort is not synced with the vent (asynchrony) -client tries to breath out when the machine is in inspiratory phase which causes a jerk movement and increased use of abdominal muscles -contributing factors include: sedation level, pulmonary edema

Question 44

high pressure alarm and interventions

Answer 44

-secretions in airway (suction) -decrease in airway size->bronchospasms (medication) -ET dislodged (retube) -vent tube kinked or obstructed (remove obstruction) -cough/gag/bite tube (suction, bite block, ready to be weaned/extubated, sedation) -anxiety (sedation, reassurance)

Question 45

low pressure alarm and interventions

Answer 45

-disconnected or leak in vent tubing or ET cuff (reconnected, check connections, assess cuff pressure