QUALCON 2022

ENGINEERING CONTROLS
&
PATIENT SAFETY
Presented by
Vinod Kumar K B
Consultant- Engineering, Maintenance,
Safety
 Some thoughts of infection control
An article entitled “Understanding and Using Measures for
Healthcare Associated Infections (HAI)” by State of New
Jersey, Department of Health in 2019, provided the
following information on hospital-associated infections:
• Healthcare-associated infections (HAIs) are among the top causes of
unnecessary illnesses and deaths in the United States.
• HAIs are infections that patients get while staying in a hospital or other
healthcare facility – infections that the patients did not have before being
admitted.
• They account for approximately 1.7 million infections and almost 100,000
deaths annually1.
• HAIs result in extra days of hospitalizations and higher health care costs.
• The estimated financial impact of HAIs is between $28 billion to $33
billion a year2.
 Engineering Controls
Engineering controls are important for preventing
infections in hospitals. The role of the engineering
team is crucial in the maintenance of the HVAC, water
supply, building and the supply lines.
 Engineering Controls
Basic requirements of environmental controls
include:
AIR
 IMPORTANT QUESTION
• Whether the patient / procedure needs to be
protected from the environment?
THIS NEEDS A POSITIVE PRESSURE AREA

• Whether the environment needs to be

protected from the patient / procedure?
THIS NEEDS A NEGATIVE PRESSURE AREA
 POSITIVE PRESSURE AREAS
• OPERATING ROOMS
• TRANSPLANT ROOMS
• ALL CONTROLLED AND AIRCONDITIONED
ROOMS
• ALL ROOMS PROVIDED WITH MORE OF FRESH
AIR AND LESS OF EXTRACT AIR
 TYPES OF OPERATION THEATRES
• TYPES OF OPERATION THEATRES
• SUPERSPECIALTY OT’S
• CVTS
• ORTHO
• NEURO
• TRANSPLANT
• GENERAL OT’S
➢OPTHALMOLOGY
➢OTHER BASIC SURGICAL PROCEDURES
 DIFFERENCE BETWEEN 2018 & 2015 NABH GUIDELINES
NABH GUIDELINES -OT
PARAMETERS SUPERSPECIALITY OT GENERAL OT
2018 2015 2014 2018 2015 2014
TOTAL AIR CHANGES PER HOUR 20 20 25 20 20 20
FRESH AIR CHANGES PER HOUR 4 4 4 4 4 4
AIR VELOCITY AT DIFFUSER GRILLE
25 - 35 25 - 35 90 - 120 25 - 35 NOT MENTIONED NOT MENTIONED
FACE - FPM
POSITIVE PRESSURE 2.5 Pa (0.25 mm) 2.5 Pa (0.25 mm) 15 Pa (1.5mm) 2.5 Pa (0.25 mm) 2.5 Pa (0.25 mm) 15 Pa(1.5mm)
CLEANLINESS LEVEL AT DIFFUSER
ISO 5 / CLASS 100 ISO 5 / CLASS 100 ISO 5 / CLASS 100 ISO 6 / CLASS 1000ISO 6 / CLASS 1000ISO 6 / CLASS 1000
GRILLE "AT REST"
21 Deg. + 3 or -3 21 Deg. + 3 or -3 21 Deg. + 3 or -3
TEMPERATURE - DEGREES
21 Deg. + 3 or -3 21 Deg. + 3 or -3 21 Deg. +3 or -3
CENTIGRADE For ORTHO For ORTHO For ORTHO
18 + 2 or -2 18 + 2 or -2 18 + 0 or -2
20% to 20% to
20% to 20% to 60%;IDEAL
40% to 60% 60%;IDEAL @ 60%;IDEAL @ 40% to 60%
60%;IDEAL @ 55% @ 55%
RH - RELATIVE HUMIDITY % 55% 55%
Washable Washable Washable
Washable Washable Washable
Flange type Flange type Flange type
Flange type Flange type Flange type
Filters in SS Filters in SS Filters in SS
Filters in SS Filters in SS Filters in SS
/Alu.casing /Alu.casing /Alu.casing
/Alu.casing /Alu.casing /Alu.casing
90% @10Microns 90% @10Microns 90%
AHU AIR FILTERS 90% @10Microns 90% @10Microns 90% @10Microns
99%@5 microns 99%@5 microns @10Microns
99%@5 microns 99%@5 microns 99%@5 microns
Hepa, 99.97%@ Hepa, 99.97%@ 99%@5 microns
(Hepa filters Hepa, 99.97%@ Hepa, 99.97%@
0.3 mcirons 0.3 mcirons Hepa, 99.97%@
only at OT 0.3 mcirons(Not 0.3 mcirons(Not
( If not available ( If not available 0.3 mcironS(Not
Terminals) compulsory) compulsory)
at OT Terminal ) at OT Terminal ) compulsory)
OPERATING ROOM HVAC EQUIPMENT
AIR CHANGES PER HOUR
Hvac ducting-supply air in OTs
Hvac ducting- return air in OTs
TYPICAL AIR FLOW PATTERN IN AN OPERATING ROOM
TYPICAL AIR FLOW PATTERN INSIDE THE OPERATING ROOM
TYPICAL AIR FLOW PATTERN IN AN
OPERATING ROOM
TYPES OF FILTERS
Are HEPA Filters effective?
• >> Most Penetrating Particle Size (MPPS)
of a HEPA Filter is that particle size for
which the HEPA filter offers the lowest
filtering efficiency
• >> Efficiency offered by a HEPA filter for
the MPPS is called “MPPS efficiency”.
• >> For all particle sizes, smaller or larger
than the MPPS, the HEPA filter offers an
efficiency that is higher than the MPPS
efficiency.
➢ Ref :
o 1) EN 1822 - 1 : 2019
o 2) Severe Acute Respiratory Infections Treatment
Centre : Practical manual to set up and manage a SARI
treatment centre and a SARI screening facility in
health care facilities, World Health Organization,
March 2020
 TECHNICAL SPECIFICATION FOR HEPA FILTERS
• FILTER SIZE : Flange Size : 1220 x 610 mm Box size : 1160 x 550 x 70 mm + 5
mm Gasket thickness & Tolerance of + or – 3 mm on the diagonals and –2 mm
to + 0 mm on the other dimensions.
• FRAME MATERIAL : Aluminum Extrusion – Anodized, Stainless Steel 304 Grade
is also preferred
• FILTRATION MEDIA : Micro Glass Fiber media
• MEDIA PROTECTION: Powder Coated Aluminum Expanded metal guard on
both sides of the filter
• SEALANT : Poly Urethane and Silicon
• SEPERATORS : Hot melt
• GASKET : Silicone Rubber Gasket
• INITIAL PRESSURE DROP : 18 mm WC at rated flow.
• FILTRATION EFFICIENCY : 99.99% down up to 0.3 microns
 GENERAL COMMISSIONING STEPS
• Adjust air flow rates
• Balance for differential pressures and fresh air
intakes
• Balance for air uniformity
• Test for Air Flow pattern
• Test for Filter Integrity
• Allow room to stabilise
• Test for Particle counts
• Test for Recovery
• Hand over to Microbiology
 OTHER REQUIREMENTS
• All return air paths to be ducted
• Do not allow for any crevices in the interior surfaces of
rooms.
• All interior surfaces must be hard cleanable and should
be non porous.
• Use Tacky mats at various places to reduce
contamination migration through traffic.
• Use Pass boxes (Dymanic/ Static) instead of opening
doors each time
• Ensure ducts are leak free by Duct leak testing
• Run the AHU 24x7 without stoppage.
 TESTS TO VERIFY CONDITIONS INSIDE THE OPERATING
ROOM

• NAME OF THE TEST EQUIPMENT USED

• TEMPERATURE THERMOMETER
• REALATIVE HUMIDITY PSYCHROMETER
• AIR VELOCITY & AIRFLOW RATES ANEMOMETER
• DIFFERENTIAL PRESSURE MANOMETER
• AIR FLOW PATTERN GLYCOL FOG& VIDEO
CAMERA
• FILTER INTEGRITY SCAN PHOTOMETER &
AEROSOL GENERATOR
• PARTICLE COUNT AIRBORNE PARTICLE COUNTER

• RECOVERY AEROSOL GENERATOR &

PARTICLE COUNTER
 ENVIRONMENT MONITORING
In ISO 14644-2 Specifications for testing and monitoring to
prove continued compliance to ISO-14644-1

Schedule of Tests to Demonstrate Continuing Compliance

Maximum Time Test
Test Parameter Class Interval Procedure
Particle Count <= ISO 5 6 Months ISO 14644-1
Test > ISO 5 12 Months Annex A
Air Pressure ISO 14644-1
Difference All Classes 12 Months Annex B5
ISO 14644-1
Airflow All Classes 12 Months Annex B4
 Air Conditioning Air Handling units Planned Preventive Maintenance Schedule 2018

Jan-18 Feb-18 Mar-18 Apr-18 May-18 Jun-18 Jul-18 Aug-18

PPM
Sl.No. Floor Location Type

1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
Frequency

week 4
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
week
Central Sterile
B2 B2-AHU-2 Critical 30 days
& Supply Dept
1
B2 Sterile Store B2-AHU-3 Critical 30 days
2
B1 B1-CSU-04 Critical 30 days
3 Dialysis-ICU
B1 30 days
4 Minor O.T B1-CSU-05 Critical
B1 Blood Bank B1-AHU-2 Critical 30 days
5
B1 Lab B1-AHU-3 Critical 30 days
6
 A TYPICAL AHU CHECK LIST
Dept. of Maintenance & Engineering
AC AHU & CSU Planned Preventive Maintenance - Service Report
Asset No. :
Asset Category :
Location :
Equipment Name:
Initial Preparations / Pre PPM Procedure. Work status
1. Notify the end user , Check with Area end user for deficiencies / complaints.
2. Use necessary Personal Protective equipments & arrange for the proper tools
Tasks & Qualitative Checks.
1. Check controls and observe the unit for normal operation.
2. Check for unusual noise or vibration.
3. Check tension, condition and alignment of belts; adjust as necessary.
4. Clean coils, evaporator drain pan, blower, motor and drain piping, as required.
5. Lubricate shaft and motor bearings.
6. Service air filters.
7. Check VFD / Bypass Starter
8. Inspect exterior piping and valves for leaks; tighten connections as required.
9. Inspect for air leakages .
10. Inspect DP sensors /Control valve / Damper actuators / Temp. Sensors
Quantitative Checks
1. Check operating Current.
2. Check Chilled water tempratures
3. Check Supply air /return air / fresh air temperature
Safety Procedures on Completion of PPM
1. Ensure that the water supply valve is open / isolating switch on / light is off
2. Close the Trap door.
3. Clean the area
4. Notify the end user.
5. Report to the immediate supervisor about the equipment status
6. Revisit required or not.

Remarks.

Work done by Checked by.

A surgical control panel display in an OT
Building management system monitoring
ISOLATION ROOMS
NEGATIVE PRESSURE ISOLATION ROOMS

• EP IS ENVIRONMENT
PROTECTION
• PP IS PATIENT
PROTECTION
• SUPPLY AIR
• EXHAUST AIR
TYPICAL ISOLATION ROOM CONTROLS
ISOLATION ROOM CONTROLS
ISOLATION ROOM WITH AN ANTE ROOM
AIR FLOW INSIDE THE ISOLATION ROOM
Engineered specifications for positive- and negative pressure
rooms
 ENVIRONMENTAL CONTROLS
Inside Operating Rooms……………….
• Contamination sources and how to control
it….
CONTAMINATION –COMMON SOURCES

• Personnel
• HVAC System
• Ingress through doors, openings, cracks,
drains etc
• Traffic (Both men and material)
• Procedure or the activity
 What do we achieve?
• Contamination dilution by ventilation
• Improvement of air quality by filtration
• Reduction in air borne exposure time by air change and pressure
differential, humidity control, organism viability (by HEPA Filtration)
and airflow patterns.
CONTAMINATION CONTROL STEPS
• Source limitation or elimination
• Creating primary (physical) barriers
• Creating secondary (indirect) barriers
• Removing entrained / generated
contaminants.
• Dilution -supply clean air continuously
 SOURCE LIMITATION / ELIMINATION
• Reduce traffic
• Stringent protocols for personnel and material
entry and exit and procedures.
• Correctly designed and operating HVAC system
• Elimination of civil defects
 PRIMARY BARRIERS
• Lay out in accordance with contamination
control principles.
• Separation of vulnerable patient residence and
movements
• Multiple compartment separation
• Provision of air locks (ante rooms) wherever
necessary.
• Provision of separate Sterile and Non Sterile
corridors in Operating suites and ICUs
 SECONDARY BARRIERS
• Air flow patterns
• Differential pressures
 REMOVING INGRESSED OF
GENERATED CONTAMINANTS
• Providing adequate number of air changes
• Effective air flow pattern to transport the
contaminants away and out of the critical
environment
• Judicious placement of the equipments
• Judicious design of personnel movement
 DILUTION
• Providing adequate level of air filtration for
the air supplied into the critical environment.
• Providing a suitable level of air filtration for
the air that is extracted from the room.
EFECT OF RELATIVE HUMIDITY
EFFECT OF RELATIVE HUMIDITY ON MICROBIAL GROWTH
WATER
 Water Management
• General requirements for water tanks are:
▪ Cleaning schedule.
▪ Records of date of cleaning, disinfectant used,
name of person who cleaned the tank.
▪ Tanks:
– Should be kept closed.
– Should be marked with details regarding type of water, tank’s
capacity, last cleaning date and due date.
– Should have water level indicator.
– Should have safe access with ladder.
 Testing drinking water

▪ Physical (Colour, odour, taste) – Daily

▪ Chemical – Once in 6 months (By accredited
facility).
▪ Biological – Every month (By the microbiology
department inhouse or outsourced).
▪ Alternate sources (bore-well, tanker, well) –
Once in 6 months.
 Water Analysis
▪ Drinking water: Once in a month.
▪ RO water (dialysis): Weekly followed by
residual chlorine check at terminal ends
before connecting to machine.
▪ Endotoxin levels: Once in a month.
▪ Scrub water: Once a week.
ISO 10500:1991
Water testing schedule
 ASHRAE STANDARDS

• ASHRAE 170 — Ventilation of Health Care Facilities (building code in approximately

40 states)
• ASHRAE 55 — Thermal Environmental Conditions for Human Occupancy
• ASHRAE 52.2 — Method of Testing General Ventilation Air-Cleaning Devices for
Removal Efficiency by Particle Size
• ASHRAE book: HVAC Design Manual for Hospitals and Clinics
 • The intensive care unit (ICU) is a potentially hostile
environment for the vulnerable critically ill patient.
• Adverse environmental factors can contribute to
delirium.
• Delirium is associated with an increased length of
hospital stay and increased mortality.
Intensive care unit environment
Tim Wenham, MBChB FRCA DICM, Alison Pittard, MBChB FRCA MD
Continuing Education in Anaesthesia Critical Care & Pain, Volume 9, Issue 6, December 2009, Pages 178–183,
https://doi.org/10.1093/bjaceaccp/mkp036
• Frequently reported stressful environmental factors are noise,
ambient light, restriction of mobility, and social isolation.
• Improving the ICU environment involves education of critical
care staff, modification of equipment, and careful
consideration to future ICU design.
 ICU’s
• Temperature (21 to 23)+/-1 deg C
• Humidity less than 60%
• Air changes per hour(outdoor air)-2
 Vinod Kumar K B
Consultant F MS- Rajagiri Hospital
Consultant MEP-V B G Consulting Engineers
9544421776
vinodkumarkb@gmail.com