Presentation is based WHO Guideline on the Techincal Specification of Ventilators to be used for COVID-19. Topics covered were Introduction to Mechanical Ventilation, Technical Specifications of ventilators and Ventilator Management specific for COVID-19 patients.

1. TECHNICAL
SPECIFICATIONS OF
VENTILATORS FOR
COVID-19

2.  Introduction to Mechanical Ventilation
 Technical Specification of Ventilators for COVID-19 – WHO
recommended
 Management Specific to COVID-19

3. WHAT IS VENTILATION ?
 Movement of Fresh Air In and
Out around an area or place

4. WHAT IS LUNG VENTILATION ?  Movement of Air IN and OUT of lung – Lung
Ventilation.
 Movement of fresh air (21% of O2) in the
lungs is called Inspiration or Inhalation (
Active Process)
 Movement of stale air ( Majority CO2) out of
lung is called Expiration or Exhalation (
Passive Process )
 Mechanical Ventilation is the ventilation of
lungs by Artificial means usually by
ventilator.

5. WHAT IS MECHANICAL VENTILATOR ?
Ventilator is a “Black Box” that generates a
controlled flow of gas into a patient’s airways.
Oxygen and Air are received from cylinders or
wall outlets, the gas is pressure reduced and
blended , accumulated with in the Black Box and
delivered to the patient lungs.
Inspiration – Active by Ventilator, Gas Delivered
to the patient.
Expiration – Passive by the patient, Gas Exhaled
by the patient.

6. NEEDFOR MECHANICALVENTILATION– EQUATION OF MOTION
Pressure
Pressure due to
resistance work
Pressure due to
elastance work

7. NEGATIVE PRESSURE VENTILATORS
Pressure
Pressure due to
resistance work
Pressure due to
elastance work
Negative Pressure

8. POSITIVE PRESSURE VENTILATORS
Pressure Resistance X Flow Elastance X Volume
Positive Pressure

9. MECHANICAL VENTILATION - GOAL
Minute
Ventilation
CO2 Removal
PEEP Fio2
Oxygenation
Respiratory Rate Tidal Volume

10. COMMON SETTINGS – CONVENTIONAL VENTILATOR
 Fi02- Fraction of Inspired Oxygen 0.21%
 PEEP – Positive End Expiratory Pressure – 5cmh20
 Trigger Sensitivity 1. Flow Trigger L/ Min 2. Pressure Trigger cmh20
 Tidal Volume
6 to 8 ml/Kg of ideal body weight
 Respiratory Rate
 Minute Ventilation
Predicted Value = 100ml/min * Ideal body weight
Eg= 70 kg *100 = 7000 ml
7.0 l/min

11. BASICS OF VENTILATIONS – W.R.T AMBU BAG
How much to Squeeze ? Tidal Volume
How many times to Squeeze ? Rate/ Frequency
When to Squeeze ? I : E Ratio
How Fast to Squeeze ? Flow ( Movement of Volume)

12. BREATHING SEQUENCE

13. COMMON MODES OF VENTILATION
Start Control Cycle
Volume Assisted
Control
Set Frequency or
Patient triggered
Flow ( Volume) Volume or Time
Pressure Assisted
Control
Set Frequency or
Patient triggered
Pressure Time
Pressure Support Patient Triggered Pressure % of peak Flow

14. COMPONENTS OF A VENTILATOR
 Power source or Input Power
1. Electrical Powered – AC and DC (Battery)
2. Pneumatically (Gas) Powered
3. Combined power Ventilator (Microprocessor
Controlled)
 Positive or Negative Pressure Ventilator
 Control Systems and Circuits
1. Closed Loop and Open Loop to control ventilator
function
2. Control Panel
3. Pneumatic circuit
 Power Transmission and Conversion System
1. Volume Displacement , Pneumatic Designs
2. Flow Control Valves
 Control Panel

15. POSITIVE AND
NEGATIVE
PRESSURE
VENTILATORS

16. CONTROL SYSTEMS
AND CIRCUITS
 Open and Closed Loop
Systems to Control Ventilator
Function
1. An aspect of computer or
microprocessor control is the
loop system. Most ventilators
that are not microprocessor
controlled are called open
loop, or "unintelligent,"
systems.
2. Closed loop systems are
described as "intelligent"
systems because they
compare the set control
variable to the measured
control variable.

17. PNEUMATIC
CIRCUIT
 Internal Pneumatic Circuit –
Flows with in Ventilator .
Single and Double Circuit
 External Pneumatic Circuit/
Patient Circuit - Flow from
Ventilator to Patients
 Humidifier or Heat
Moisture Exchange Filters

18. CONTROL PANEL AND USER INTERFACE

20. CLASSIFICATION OF VENTILATORS
 Negative Pressure Ventilator
 Positive Pressure Ventilator
1. Volume Cycled
2. Pressure Cycled
3. Time Cycled
 Home Ventilators – Non Invasive Ventilators
 Transport Ventilator

22.  Major Types of Ventilators Required
Invasive Ventilators
1. Patient Ventilators for ICU
2. Patient Ventilators for Transport/ Mass Causality
Non- Invasive Ventilators
1. Continuous Positive Airway Pressure (CPAP)
2. Bi-Level Positive Airway Pressure (Bipap / BPAP)

25. MAJOR OBSERVATIONS IN THE SPECIFICATIONS IN INVASIVE VENTILATORS
 Ventilation Modes
1. Pressure Control
2. Volume Control
3. Pressure Support
4. Pressure Regulated Volume Control (PRVC)
5. Synchronised Intermittent Mandatory Ventilation
6. Non Invasive Capability

26. PRESSURE CONTROL MODE
Inspiration
Expiration
Paw
Time

27. VOLUME CONTROL MODE
Inspiration
Expiration
Time
Volume
Tidal
Volume

28. PRESSURE SUPPORT MODE
Inspiration
Expiration
Paw
Time

29. SYNCHRONISED INTERMITTENT MANDATORY VENTILATION

30.  Monitored and Controlled Parameters -
Intensive Care Patient Ventilator for Adult
and Paediatric
1. Fi02 – 21 to 100%
2. Tidal Volume – 20-2000 ml
3. Inspiratory Flow – 1-160 L/min
4. Inspiratory Pressure – 0-40 cmh20
5. I:E Ratio ; I:E Inverse Ratio
6. RR – 0-06 Breaths / Min
7. Inspiratory Pause
8. Peak Pressure limitation 5-20 cmh20
9. PEEP 0-20 cmh20
 Monitored and Controlled Parameters - Patient
ventilator for Transport / Mass Casualty
1. Air and Externally supplied oxygen mixture ratios
fully controllable
2. Fi02 – 21 to 100%
3. Tidal Volume – 20 – 1000 ml
4. Inspiratory Pressure – 0 – 40 Cmh20
5. I.E Ratio
6. RR 10- 60 Breath/min

31.  Displayed Parameters ( Colour and Graphics
Preferences ) ICU Ventilator
1. Display easily readable in low ambient light and
sunlight.
2. 3 scalar waveforms: pressure, volume and flow.
3. 3 loop (axis) displays: pressure-volume, flow-
volume and pressure-flow, preferable.
4. Status indicators for ventilator mode, battery
status, patient data, alarm settings.
5. FiO2.
6. Airway pressures (peak, plateau mean and PEEP).
7. Tidal volume (inspired and expired).
8. Minute volume (inspired and expired).
9. I:E ratio
10. RR (spontaneous and mechanical)
11. End-tidal CO2.
 Displayed Parameters – ( Colour and Graphics Preferences )
Transport Ventilator
1. Display easily readable in low ambient light and sunlight.
2. Real time scalar waveforms for flow, volume and pressure at
least 2 simultaneously.
3. Status indicators for ventilator mode, battery status, patient
data, alarm settings.
4. Airway pressures (Peak, Mean and PEEP).
5. Tidal volume (Expired).
6. Minute volume (Expired).
7. I:E ratio.
8. Inspiration and expiration times.
9. Spontaneous Minute Volume.
10. RR.
11. FiO2. Occlusion pressure detection;
12. Air and oxygen pressure;
13. Spontaneous ventilation;
14. Leak percentage.

32.  Alarms, Related to Gas delivery –ICU
Ventilator
1. Adjustable, visual and audible for:
2. High/low FiO2;
3. High/low inspiratory pressure and PEEP;
4. High/low tidal volume (not achieved or
exceeded);
5. Apnoea, adjustable from 10-30 sec;
6. High/low respiratory rate;
7. Continuously high pressure/occlusion;
8. Breathing circuit disconnect.
 Alarms, Related to Gas delivery –Transport
Ventilator
1. Visual and audible for:
2. High/Low FiO2;
3. High/Low Flow;
4. High/Low Inspiratory pressure;
5. Breathing circuit disconnect;
6. Apnoea.

33.  Alarms, Related to Equipment
Operation–ICU Ventilator
1. Visual and audible for:
2. Gas supply failure;
3. Power failure;
4. Low battery.
.
 Alarms, Related to Equipment Operation –
Transport Ventilator
1. Visual and audible for:
2. Gas supply failure;
3. Power failure;
4. Low battery.
.

35. CONTINUOUS POSITIVE AIRWAY PRESSURE
 CPAP – It’s a spontaneous breathing mode in which airway
pressure is kept constant throughout the respiratory cycle
 It most commonly used a weaning technique . In
Neonates, CPAP is the method of choice.
 Respiratory Rate, Tidal Volume and Inspiratory Time are
determined by patient. It provides PEEP for spontaneous
breathing patient.

37. BI-LEVEL POSITIVE AIRWAY PRESSURE
 S – Spontaneous Mode – Device senses the patient
breath and triggers Insp Pressure (IPAP) in response to
increase flow and cycles into EXP Pressure (EPAP) at the
of inspiration
 T – Timed Mode – Fixed Breath Rate and Fixed
Inspiratory Time set by clinician are supplied regardless the
patient effort
 S/T – Spontaneous / Timed Mode – The device
augments any breath initiated by the patient, but will also
supply additional breaths if the patient breaths falls below
the Clinician’s set Back up Breath rate.
 PC/ PAC – Inspiration time is pre-set in PAC Mode, There
is no spontaneous/ flow cycling . Inspiration can be
triggered by patient when respiratory rate is above pre set
value or time triggered breaths will be delivered at the
up breath.

38. COMMONSPECIFICATIONS
 Power supply, Voltage, frequency and plug vary across the countries
1. Operates from AC power electric line: 100 to 240 V~ / 50 to 60 Hz.
2. Built-in rechargeable battery.
3. Automatic switch from AC power electric-line mode to battery operating mode and
vice versa.
4. Equipment must be connected to a reliable and continues source of energy
5. Continuous in battery operating mode with standard ventilation not less than 1
hour.
6. Total re-charging time not greater than 6 hours.

39. MANAGEMENT
SPECIFIC TO COVID-19

42. RECOMMENDATIONS WHEN USING VENTILATORS – COVID 19
 Complete PPE KIT
 Use of filters and circuits
1. The filter close to the patient aims to protect caregivers when the patient is infected.
2. The filter at the device air outlet will protect in case the device would be contaminated
 The device air in-let filter has not been validated against providing filtration of any type of pathogens and is intended as a
dust/ particle filter only.
 Only use Low Resistance Bacterial filters
 Replace the filters as per recommendations of supplier If recommendations are not clear,
1. Replace Filters every 24H
2. Replace filters in between patients
3. Replace filters when visually contaminated
 Lint free cloth and Ethanol 70% to disinfect the external surface of the devices

45. REFERENCES
 http://www.edx.org/ - Mechanical Ventilation course
 Handbook of Mechanical ventilation – B Umesh
 ACME – Asiaed Collegium of Medical Education – COVID-19 Management protocol for Hospitalized patients.
 http://www.breas.com/
 http://educationbybreas.com/
 Technical Specification for invasive and non invasive ventilator for covid-19 . WHO interim guidance 15 April
2020

46. THANK YOU