Chapter 5: Mechanical Ventilation Flashcards
7 advantages of Noninvasive Positive Pressure Ventilation
- reduced need for sedation
- preservation of airway predictive ventilation
- Avoidance of upper airway trauma
- decreased incidence of nosocomial PNA and sinusitis
- improved comfort
- shorter length of stay in ICU and Hospital
- improved survival
(p63)
8 disadvantages of Noninvasive Positive Pressure Ventilation
- Claustrophobia
- increased workload for RT, nurse, physician
- pressure lesions
- unprotected airway
- can’t do deep suctioning
- gastric distension
- upper extremity edema , axillary vein thrombosis, tympanic membrane dysfunction
- Delayed intubation
(p63)
In what patient type is NPPV best utilized
Alert, cooperative, and expected to improve (p64)
Causes of Hypoxemic Respiratory Failure likely to respond to NPPV
Cardiogenic Pulmonary Edema WITHOUT hemodynamic instability
Mild to moderte PJP
Respiratory failure in immunocompromised patients
(p65)
Causes of Hypercapnicn Respiratory Failure likely to respond to NPPV
Acute COPD exacerbation
Acute Asthma exacerbation
Respiratory failure in CF patients
(p 65)
IPAP greater than ____ can lead to gastric dissension
20
p(65)
Contraindications to NPPV (11)
Cardiac or respiratory arrest hemodynamic instability MI or arrhythmia Noncooperative inability to protect airway high aspiration risk active upper gi bleed sever hypoxemia severe encephalopathy facial truma significant agitation (p66)
How long to wait for improvement before switching from NPPV to invasive
no improvement in 1-2 hours or when therapeutic goals have not been met at 4-6 hours (p66)
Avoid inspiratory pressures greater than ____ mm H2O to avoid gastric dissension
20
p66
A ___ ____ breath aka ____ _____ ensures the delivery of a preset tidal volume (unless peak pressure) is exceeded
Volume-cycle or volume assist
With volume assist/cycle what does worsening airway resistance due to peak inspiratory pressure
increases
A ____ ____ or ___ _____ ____ breath applies a constant pressure for a preset time.
time cycled, pressure assist control
What does an increase in resistance alter in time cycled/pressure assist control do?
changes tital volume
How does Flow cycle/ pressure support breath work
The patient imitates every breath and the ventilator delivers support with a preset pressure value. Patient sets rate and tidal volume. breaths are terminated when the flow rate decreases to a predetermined percentage of initial peak flow.
Assist control breaths can be delivered with either ___ or ____
volume cycle or time cycled breaths
Pressure support ventilation provides a preset level of ____
inspiratory pressure, to help overcome disease process.
What type of breaths in PSV
flow cycled
in PSV the patient controls the ___ and exerts sting influence on ____
RR, duration of inspiration
Synchronized Intermittent Mandatory Ventilation can deliver what kinds of breaths
volume or time cycled
In SIMV when no effort is detected _____
the ventilator delivers the preset Vt at preset time elapsed rate
AC Ventilation Advantages and Disadvantages
Advantages: Patient can increase ventilatory support, reduced work of breathing compared with spontaneous breathing
Disadvantages: excessive inspiratory pressures
AC volume ventilation Advantages and Disadvantages
Advantages: Guarantee delivery of set Vt (unless peak pressure is exceeded)
Disadvantages: excessive inspiratory pressures
ac pressure ventilation Advantages and Disadvantages
Advantages: Limitation of peak inspiratory pressures, variable flow rates, accommodates to patients demaNDS
Disadvantages: Vt Increase or decrease with lung resistance/compliance changes
Pressure support ventilation Advantages and Disadvantages
Advantages:
comfort, improved patient/ventilator interaction, decreased work of breathing
Disadvantages: apnea alarm may not trigger backup ventilation mode. Variable patient tolerance
synchronized intermittent mandatory ventilation Advantages and Disadvantages
Advantages: less interference with normal cardiovascular function
Disadvantages: increased work of breathing compared to AC
controlled mechanical ventilation Advantages and Disadvantages
Advantages: rests respiratory muscles completly
Disadvantages: Requires sedatives/neuromuscular blockade, adverse hemodynamic effects
Most common mechanical ventilation type used
AC
What variables influence peak inspiratory flow
flow rate. diameter of tube, secretions, bronchial diameter
What should inspiratory plateau pressure be kept at
<30 mm H20
What prophylactic measures should be taken when a patient is mechanically ventilated
PPI or H2 blocker- gastric stress ulcers
DVT prophylaxis- mechanical or pharm
elevate head of bed to 30 degrees , oral hygiene, daily evals to stop mechanical vent to stop PNA
normal amounts if PEEP applied
8-15 cm H2O
Mechanical ventilation goals in ARDS
PaO2 55-80
PPlat <30
Vt 4-6 ml/kg PBW
pH > 7.15 is acceptable
What vent settings to start with ARDS
AC with Vt of 8ml/kg PBW
- decrease by 1 ml/kg over next 4 hours until Vt is 4-6 ml/kh
- if Pplat is >30 decrease Vt by 1 ml/kg until Vt is 4 or arterial pH reaches 7.15
- If using Vt 4 ml/kg and Pplat is <25 Vt can be increased by `ml/kg until Pplat is 25cm H2O or Vt is 6ml/kg
- If Pplat of <30 has been achieved with Vt >6 ml/kg and lower Vt is clinically problematic it is acceptable to maintain high Vt
Initiation of PEEP in ARDS starting point
5 CM H20 and titrate up 2-3 cm
full recruitment effect may not be apparent for several hours
monitor BP, HR and Pao2 while on PEEP
Optimal Peep settings are typically 8-15 cm H20
First consideration when hypotension occurs immediately after ignition of mechanical ventilation
tension pneumothorax
Why are patients with obstructive lung disease prone to auto PEEP
need for prolonged expiratory phase
