Card Set Information
What do you look at when evaluating a patient?
use of accessory muscles
work of breathing
RT Dept. maintains a record or a flow sheet of the following
Basic pt. info
-name, diagnosis, age, ht, wt, IBW
-mode, MV, TV, Peak, Plateau, Compliance, Initial parameters, ET size, ABG's
-alarms and correct settings
What do you do in your initial assessment
Listen to breath
: adequate volumes & proper tube placement
: apnea, low & high pressure, power failure
: 15 min after
: tube placement
: If auto PEEP or PEEP is present harder to assist
Minute ventilation, tidal volume, and rate
: machine tells
: affected by closed suction & HME
Three factors to consider with alveolar ventilation
normal mechanical deadspace
added mechanical deadspace
Normal Mechanical Deadspace
vent circuits volume lost up to 75-150 mls
caused by artificial nose
calculated as 1 ml/Ib of IBW
subtracted from delivered TV to estimate alveolar ventilation
using an ET tube changes calculated anatomical deadspace-1 ml/kg of IBW
Added Mechanical Deadspace
must be subtracted to determine actual alveolar ventilation
final alveolar ventilation calculated (TV-Anatomic)x(f)=minute volume
Peak inspiratory pressure
highest pressure during inspiration
used to calculate dynamic compliance
use insp. pause control
press. drops during hold
calculate static compliance
What modes do you have a set pressure in?
Volume changes with compliance & resistance
What is mean airway pressure affected by?
peak inspiratory pressure
end expiratory pressure (PEEP)
Could affect cardiac output
End expiratory pressure
measures Auto Peep
allows longer time to exhale
If pressure limit is activated patient may need
lung compliance decreased
pt. is coughing or biting tube
water may be inline
checking for leaks
check vent circuit
late stage carcinoma
Systemic arterial BP
CVP-measure at the end of a expiration
Exam of chest-BS
Monitor cuff pressure
every 8-12 hrs
don't exceed 25 mmHg
Decrease risk of tracheal narcosis, min. leak techn., min. occluding tech.
What causes decrease static compliance?
How is decrease static compliance easily detected?
1. BS, percussion sounds, palpation, x-ray
2. decreased compliance implies vent. is less effective
3. results in decreased PaO2 and increase PaCO2
4. pressure limited vent will need an increase in pressure to deliver an adequate volume.
if constant or decreased & static is decreased=lung compliance down
if decreased & static constant=airway resistance increased
When does airway resistance increase?
Calculate airway resistance
Norm. .6-2.4 cmH2O/l/sec
ET tube increass to 6 cmH2O/l/sec
Bronchospasm increases from 3-18 cmH20/l/sec
How do you compensate for airway resistance?
removing obstruction or decreasing flowrate
What do delivery of oxygenation to the dissues depends on?
arterial oxygen content
PaO2 desired x FiO2 known/PaO2 known
Selection of PEEP
adequate for pt. to maintain PaO2
if more than 50% of FiO2 is needed
Four basic categories of hypoxia
-cells are unable to utilize oxygen
- hemoglobin concentrations lower than norm. unable to transport O2.
- cardiovascular system fails to transport O2
- hypoventilation, shunting, vent perfusion mismatching and diffussion defects.