trouble shooting of VR

8/7/2019 trouble shooting of VR

http://slidepdf.com/reader/full/trouble-shooting-of-vr 1/40

Mechanical Ventilators



Mechanical

Ventilation



I. Objectives:

y Define mechanical ventilation.

y To learn the different major modes of mechanical

ventilation.

y To familiarize one·s self with the major parts and settings of

the mechanical ventilator.

y Describe appropriate nursing actions when each of the

major ventilator alarms sound.



II. Definition of terms:

M echanical Ventilation:

Forces air into the lungs either invasively(endotracheal tube or tracheostomytube)or non-invasively (mask) using mechanical ventilators



To achieve the goals without

damaging the lungs

To optimize gasexchange

To reproduce the body'snormal breathing

mechanism



Abbreviations:ETT: Endotracheal Tube PEEP: Positive End Expirator y Pressure

CPAP: Continuous Positive Airway Pressure, PEEP with no rate

PIP: Peak inspirator y pressure

MAP: Mean Airway Pressure

RR: Respirator y Rate Ti,Te: Inspirator y and expirator y times

I:E: Ratio of inspirator y to expirator y time

Vt: Tidal Volume, volume of each breath

SaO2: arterial oxygen saturation determined by arterial blood gas analysis

SpO2: arterial oxygen saturation determined by pulse oximetr y

FiO2: Fractional inspired oxygen HFV: High Frequency Ventilation

HFOV: High Frequency Oscillator y Ventilator/Ventilation

Amplitude: (aka Delta P) Setting on HFV. Difference between

maximum and minimum airway pressure



Basic physics related to mechanical

ventilation

In simple terms the lung-ventilator unit can be thought of

as a tube with a balloon on the end with the tube representing

the ventilator tubing, ET tube and airways and the balloon the

alveoli.



M

anually bag thepatient



Bilevel Positive Airway

Pressure Ventilation (BiPAP)



M echanicalVentilator

-is a machine that generates acontrolled flow of gas into a patient·s

airways with either negative pressure

(iro

n lung)o

r po

sitive pressure.



Negative pressure mechanical ventilators, like

the iron lung, encased the thoracic cavity externally in

an air-tight chamber . The chamber was used to create anegative pressure around the thoracic cavity, thereby

causing air to r ush into the lungs to equalize the

pressure. The iron lung is shown below.



Three Types of Ventilators

1. Volume-cycled

- Ventilator delivers gas until a set tidal volume has been

achieved regardless what the pressure would be.

E.g. Normal lung: TV = 500cc with PIP = 15

Stiff lung: TV = 500cc with PIP = 35 or 45

2. Pressure-cycled

- Ventilator will cycle & will deliver that preset TV

until the ventilator senses that it has obtained the

set pressure.E.g. PIP = 25 Ventilator is triggered Gas is delivered via ET

PIP of 25 is

reachedVentilator cycles off Enter exhalation phase

Classified accdg to cycling

mechanism



Three Types of Ventilators

3. Time-cycled

-is used much less frequently

- in the past used in anesthesia machines

- Preset inspirator y time

E.g. Set @ 3 sec. Ventilator is triggered Gas f lows for 3 sec.

As 3 sec is

reached

Flow of gas is

terminated



III. Modes of Ventilation

H ow the patient interacts w/ the mechanical ventilator

1. Controlled Mechanical Ventilation (CMV)

Ventilator is set to deliver a certain volume of gas in a

set period of time.

Rarely used.

E.g. R R = 10 bpm & TV = 500cc

This means, the patients receives 500cc ever y 6 seconds

What happens if the patient breathes @ 8x or 20x per

minute? Or initiates a breathe @ 3 seconds?

What happens if the patient takes a TV= 200cc or 700cc?




2. Assist Control Mode - AC

The ventilator guarantees that the patient will

receive the set minimum number of breaths, although

he/she is able to demand (trigger) more.

Most commonly used mode.

E.g. TV = 500cc; BUR = 10 bpm

This means that the patient receives 500cc ever y 6 seconds.

What happens if the patient initiates a breathe @ 3 second?

What happens if the patient wants 200cc of breathe?

TV= 500cc given.

TV= 500cc




3. Synchronized Intermittent Mandator y Ventilation

(SIMV)

Weaning mode

Advantages:

Patient is able to maintain their respirator y strike

It is more comfortable

Mean airway pressure is less

Less hyperventilation

In contrast with AC mode, SIMV mode allows the

patient to have their own rate & tidal volume.




4. Positive End Expirator y Pressure (PEEP)

Is the level of baseline pressure during the use of a

separate mode of ventilation.

Use in conjunction

with other modes

It prevents closing of alveoli.

E.g.

PEEP @ 5 cm H20




5. Pressure Support Ventilation

Overcomes the resistance of ventilator tubings

Decreases the work of breathing

E.g. TV = 500cc & PIP = 30Patients in the ICU unit:

They may need to breathe adequate spontaneous breathe of

500cc 10/12x a minute but, they can¶t.

Pressure support ventilation mode augment pressure

support

Therefore, the work they do to get 400cc gets them 500cc.



Complications

1. Nosocomial Pneumonia

2. Barotrauma

Not only due to high pressures

Due to high volumes and shear injur y

Damages the alveolar tissue & leads to alveolar r upture

3. Gas trapping

Occurs if there is insufficient time for alveoli to empty

before the next breath. E.g., asthma & COPD

4. Cardiovascular compromise

Due to high intrathoracic pressure. In an extreme case can

lead to cardiac arrest with pulseless electrical activity.



Part I ± In summar y

1. Three types of ventilators:

Volume-cycled

Pressure-cycled

Time-cycled

2. Modes of Ventilation

CMV

AC SIMV

PEEP

Pressure support

3. Complications

Nosocomial pneumonia

Barotrauma

Gas tapping

Cardiovascular

compromise



IV. Ventilator Controls and Settings

(Puritan Bennett)

A. Panel Controls:

1. Normal Volume/ML or Tidal Volume:

- each volume of air that the clientreceives with each breath

- spirometer indicates whether the patient is receivingcorrectTV or amount delivered with each machine breath



2. Rate:

- number of ventilator breaths delivered per minute (set as

desired)

3. Peak flow:

- set f or peak unrestricted flow

- start at approximately 40LPM, adjust to

accordance with volume and rate settings



4. Power

5. Normal Pressure Limit and sigh pressure limit

6. Sensitivity:

- set f or patient eff ort to trigger inspiration

7. Manual Normal, Manual Sigh, Sigh volume



8. Oxygen percentage or FiO2

9. Expiratory resistance

10. Nebulizer

B. Panel Indicator Lights:

1. Assist:

- lights if patient triggers inspiration

- also lights if sensitivity is overset



2. Pressure:

- lights if system pressure reaches set limit

- check f or airway o bstruction

3. Ratio:

- lights if inspiration is longer than expirationwhen unit is controlling

4. Sigh:

- lights during a sigh breathing cycle

- may be used to prevent atelectasis



5.

Ox

ygen:

- lights green if with oxygen enrichment

- lights red if oxygen supply is inadequate

- at turn on, may light red momentarily; this

denotes proper initial filling of the accumulator



C. Other Controls and Indicators:

1. Spirometer ² indicates TV

2. Spirometer alarm

3. Humidifier

4. Thermometer

5. Pressure alarm ² sounds if system pressure

reaches set limit

6.

Ox

ygen alarm7. Temperature alarm

8. PIP/Peak Inspiratory pressure



IV. Sharpening your skills - trouble shooting

VR:

A. Assessment:

1. How severe is the pro blem?

2. Does the patient require immediate

resuscitation?2. Check:

2.1 Is the chest moving and is it moving

symmetrically?

2.2 Is the patient cyanosed?



2.3 What is the arterial saturation?

2.

4 Is the patient hemo

dynamically stable?

3. Diagnosis:

- ventilator/ circuit pro blems can be distinguished

from ET or patient pro blems by taking the patient

off the ventilator and continually bagging the patient

with a self

² inflating resuscitator.



IV. B. Identifying Causes of Alarms:

1. High airway pressure:

Why does it matter?

a. High airway pressure may cause barotrauma b. It signifies a deterioration in the patients

clinical state.

c. It may result in hypoventilation of the patient .

Many ventilates cycle from inspiration to expiration immediately if the pressure alarm

limit is reached.



as a result, inspiration is terminated early and the tidal volume is

reached.

Causes:

a.Ventilator pro blems:

- excessive tidal volume

- excessive flow or expensively short inspiratory

time

- high airway pressure alarm limit too low



2.Ventilator malfunction ² rare

b. Circuit pro blems:

1. Fluid pooling in circuit ² empty

2. Fluid pooling in filter3. Kinking of circuit - fix



C. ET Obstruction:

1. due to sputum ² needs suctioning

2. Patient is coughing or holding her breath or is

biting the ET

D. IncreasedAirway Resistance

1. bronchospasm



E. Decreased Respiratory System Compliance:

1. Parenchymal disease

2. Pleural disease (pneumothorax/hemothorax)

3. Decreased chest wall compliance

e.g. Patient is anxious or fights the ventilate4. Decreased Ventilated lung volume

a. Sputum plugging ² good suctioning

b. Labor/ lung collapse

c. Endo bronchial intubation



1.Assess patient

2. Disconnect patient from ventilator and manually

ventilate using self ² inflating resuscitator.

Assess the ´feelµ of the lungs. If the patient is

difficult to ventilate it is a pro blem with the

endotracheal tube or the respiratory system.

3.

Fo

r ventilato

r and circuit pro blems, check ventilat

or

settings and function, and check circuit f or o bstruction

or kinking.

Management:



Fo

r patiento

r ET

pro blems, e

xamine the patient l

ookingparticularly f or wheeze, asymmetrical chest expansion and

evidence of collapse. Pass a suction catheter through the ETT to

check its patency.

4. Chest X ²ray ² needs doctor·s order.

5. Contact RCS personnel



Low pressure alarms goes off:

1. Patient is ́ overbreathingµ ² drawing more air than theventilator delivers.

2. There·s a leak in the system, from a hole in the tubing, adisconnected tube, a leak around the cuff, or a leak inthe humidifier.



Thank you !!!

trouble shooting of VR

Documents

Transcript of trouble shooting of VR