How Ventilation Works

Question 1

One torr equals how many mmHg

Answer 1

One. they and equivalent

Question 2

One ATM equals how many cmH2O

Answer 2

1034cmH20

Question 3

At the start of a breath the alveoli is negative?

Answer 3

2-3

Question 4

At the end of expiration the intrapleural pressure drops to

Answer 4

-10 cmH2O

Question 5

At the end of inspiration the intrapleural pressure drops to

Answer 5

-10 cmH2O

Question 6

What is the transrespiratory pressure

Answer 6

The pressure difference between the Aw opening and the body surface

(Pressure required to inflate the lungs during PPV)

Question 7

Goals of mechanical ventilation

Answer 7

Provide O2
Provide alveolar ventilation
Avoid alveolar over distention
Maintain alveolar recruitment
Promote patient-ventilator synchrony
Avoid auto PEEP
Use the lowest possible FiO2

Question 8

Define negative pressure

Answer 8

Generates a negative pressure at the body surface, transmitted to pleura space.

Question 9

Parts of a ventilator

Answer 9

Power Supply
Battery management unit
Control board
User interface
Other technologies

Question 10

What are the other technologies on the ventilator

Answer 10

Pressure sensor
Flow sensor

Question 11

How are ventilators powered

Answer 11

Alternating current (A.C.) 120V

Direct current (DC) 12V battery
(Short term transport or backup power)

Question 12

What do electrically powered ventilators work off

Answer 12

Controlled motors
Electromagnets
Potentiometer
Rheostats
Computers

Question 13

Pneumatically powered ventilator components

Answer 13

Needle valve
Venturi entrainment
Flexible diaphragms
Spring loaded valves to control flow

Question 14

When is Pneumatically powered ventilators used

Answer 14

Transport, MRI, or power fail

Question 15

Types of battery powered ventilator

Answer 15

Bear 33
PB 2801 Companion

Question 16

What does the control system do

Answer 16

Interprets the operators settings and regulates the desired outcome

Question 17

How does the open loop system work

Answer 17

Not a microprocessor (unintelligent)
Cannot respond to changing conditions

Question 18

How does a closed system work

Answer 18

Compares set control and adjust occurring to patients changes. (Intelligent)

Question 19

What does the compressor in the ventilator do

Answer 19

Reduces internal volumes to generate a positive pressure at the

Question 20

Types of compressors

Answer 20

Piston drive
Use rotating blades
Moving diaphragms
Bellows

Question 21

What are the ventilator displacement designs

Answer 21

Bellows and concertina bags

Question 22

How does a ventilator Rotary drive piston bellow work

Answer 22

Lelectric motor rotated a drive wheel

Creates a sinusoidal flow waveform (increases at the start of inspiration and tapers)

Question 23

What types of ventilator concertina bags are there

Answer 23

Linear drive piston:
Electrical motor connected by gears to pistons

Springloaded bellows
Adjustable spring on top of a bellows applies force
(No longer manufactured)

Question 24

How are solenoid valves controlled

Answer 24

Electrical timers
Microprocessor
Manual operation or pressure

Question 25

What do fluidic ventilators rely on

Answer 25

Wall attachment and beam deflection Are analogous of electronic logic circuits (used only occasionally)

Question 26

Schema of modern mechanical ventilators

Answer 26

Electronically and Pneumatically controlled Sensors measure pressure and flow Microprocessor control Inspiratory and expiratory valves Expiratory valve controls PEEP

Question 27

Define NIV

Answer 27

Delivery of positive pressure through a natural aw

Question 28

Evidence for the indication of HHFNC

Answer 28

Acute hypoxemia respiratory failure Risk of post extubation hypoxemic respiratory failure

Question 29

Unsupported Evidence for indication of HHFNC

Answer 29

COPD Asthma Cardiogenic pulmonary edema

Question 30

What does BiPAP stand for

Answer 30

Bilevel Positive Aw Pressure

Question 31

Indication for CPAP

Answer 31

Acute care (Decreases preload and after load) Need a adequate spontaneous ventilation workload

Question 32

What should the CPAP initial pressure be

Answer 32

5-10cmH2O

Question 33

Where can the FiO2 be set at the start of CPAP

Answer 33

100% and can be tapered down

Question 34

Parameters for OSA

Answer 34

A reduction in ventilation of at least 50% that results in a decrease of arterial saturation of 4-more percent. Caused by partial aw obstruction

Question 35

Equation of motion

Answer 35

Pmus+Pvent= resistance (flow) + elastance (volume)