MECHANICAL VENTILATORS

MECHANICAL
VENTILATORS


DEFINITION
MECHANICAL VENTILATOR IS A
POSITIVE / NEGATIVE
PRESSURE BREATHING DEVICE
THAT CAN MAINTAIN
VENTILATION ANDOXYGEN
DELIVERY FOR A PROLONGED
PERIOD.


ANATOMY AND
PHYSIOLOGY


OXYGEN DISSOCIATION CURVE


INDICATIONS
A) RESPIRATORY FAILURE
(1) PaO2<60mmHg

(2) PaCO2>50mmHg
B) CNS DISORDERS
(1) OVERDOSE OF SEDATIVES
(2) CVA
(3) GUILLAIN BARRE
SYNDROME

INDICATIONS( CONTD)
C) MUSCULO SKELETAL & PLEURAL-FUNCTION
(1)KYPHOSCOLIOSIS
(2)FLAIL CHEST
(3)PLEURAL EFFUSION
(4)PNEUMO/HAEMOTHORAX

D) CONDUCTIVE DISORDER
(1)UPPER AIRWAY OBSTRUCTION
(2)EPIGLOTTITIS
(3)SLEEPAPNOEA
(4)ASTHMA
(5)BRONCHOSPASM


CONTD…
E) DISORDER OF GAS EXCHANGE
(1)PNEUMONEA
(2)PULMONARY OEDEMA
(3)ARDS
(4)ASPIRATION
(5)CYSTIC FIBROSIS
(6)SMOKE INHALATION
F)NEONATALCONDITIONS
(1)HYALINE MEMBRANE DEFICIENCY
(2)MECHONIUM ASPIRATION
(3)PRETERM LABOUR

TYPES OF MECHANICAL VENTILLATORS


NEGATIVE PRESSURE
VENTILATOR
• IRON LUNG


BODYWRAP / PNEUMOWRAP / TORTOISE
SHELL


POSITIVE PRESSURE VENTILATORS
•Inflate

the lungs by
exerting positive
pressure on the airway,
forcing alveoli to expand
during inspiration
•Expiration occurs
passively


TYPES OF POSITIVE-PRESSURE
VENTILLATORS
• PRESSURE-CYCLED
• TIME CYCLED
• VOLUME CYCLED

• NON INVASIVE POSITIVE PRESSURE
Eg: BIPAP


MEDLEY OF MODES
• CONTROLLED MANDATORY VENTILATION
• ASSIST CONTROLLED MODE
• INTER MITTENT MANDATORY VENTILATION
• SYNCHRONIZED INTERMITTENT MANDATORY
VENTILATION
• PRESSURE SUPPORT VENTILATION
CPAP/PEEP
BiPAP
T-piece




SIGH-a life saver



PROBLEMS WITH MECHANICAL
VENTILATION

• PROBLEM
Increase in peak air
way pressure

• CAUSES

Coughing
Bucking
Decreased lungcompliance
Tubing kinked
Pneumo thorax
Atelectasis


PROBLEMS WITH MECHANICAL
VENTILATION - contd
Decrease in pressure
/ loss of volume

Increase in compliance
Leak in ventilator / tube
/ humidifier


PROBLEMS WITH MECHANICAL
VENTILATION – contd
• PATIENT
Cardiovascular-

compromise

Barotrauma/
pneumothorax

Pulmonary
infection

Decreased in venous
return
High mean airway
pressure lead to
alveolar rupture
Bypass of normal
defense mechanism


BUCKING THE VENTILATOR
Its management
CAUSES
Anxiety
Hypoxia
Increased secretion
Hypercapnia
Pulmonary edema


MANAGEMENT FOR
BUCKING
• Muscle relaxant
• Tranquilizers
• Analgesics
• Paralyzing agent


NURSING MANAGEMENT
Enhancing gas exchange

Promoting effective airway clearance
Preventing trauma and infection
Promoting optimal level of mobility
Promoting optimal communication
Promoting coping ability


RESPIRATORY WEANING
CRITERIA
 VITAL CAPACITY -10-5-15ml/kg
 MAXIMUM INSPIRATORY PRESSURE =
-20mm of WATER
 TIDAL VOLUME =7-9ml/kg
 MINUTE VENTILATION -6Liter/minute
 PAO2 >60mm of hg
 STABLE VITAL SIGNS AND ABG


STEPS OF WEANING
Volume control mode
SIMV
CPAP
T-piece
Mask