ward isolation suite basic concepts and research … · isolation suite research project ¾research...

WARD ISOLATION SUITEBASIC CONCEPTS and

RESEARCH PROGRAMME

Malcolm ThomasConsulting Engineer

01132 582788March 2006

DHDH EstatesEstates & & FacilitiesFacilities 2

Isolation – Fact and FictionIsolation is required!When admitted, patients condition unknownLevels of protection:-1. A closed door2. Universal nursing precautions3. Medication4. VentilationComplicated systems are unreliableStaff change; knowledge is lost


Single room

Corridor

Doorway

Extract fan

(Optional)

WC

(Optional)

E

Bed

View panel

Window


Negative pressure isolation room with lobby

CorridorBed door

WC

Lobby

E

Staff door

E

E

S

Bed

View panel


Switchable airflow isolation room with lobby

CorridorBed door

WC

Lobby

S

E

Staff door

S

E

E

Bed

View panelNot Recommended!


Summary of current UK situation

Many different types of room installed

“On site” staff knowledge poorNursingEstates and Facilities

Many rooms modifiedDo not work as intendedChange of use


Types of Isolation RoomsPositive pressure room• Transplant units / ChemotherapyNegative pressure room• Infectious diseases unitsSwitchable room (Positive / Negative)• Wards / ITU / HDU

Neutral pressure room with Ventilated lobby• New concept• Universal application?


Isolation room, en suite and ventilated lobby

CorridorAccess door

En suite

Lobby

E

S

Transfergrille

Pressurestabiliser

Bed

View panel

Locked / Sealed window


Isolation room, en suite and ventilated lobby (Schematic of alternative layout)

Bed door

En suite

Lobby

E

Staff door

S

Transfergrille

Pressurestabiliser

Bed

View panel

Locked / Sealed window and Solid ceiling


CorridorBed door

En suite

Lobby

E

Staff door

S

Transfergrille

Pressurestabiliser

Bed

View panel

Locked / Sealed window

Neutral10 ac/h

-ve; Min 10ac/h

+ve 10Pa

and Solid ceiling

Isolation room – Pressure and flow regime


Corridor

En suite

Lobby

E

Staff door

S

Transfergrille

Pressurestabiliser

View panel


+ve

-ve

Neutral


Nominal Ventilation Parameters

Lobby:- Pressure to corridor 10 PascalsSupply air flow 208 - 238L/sAir change rate 63 - 69 per hour

Isolation room:- Pressure to corridor Nominally ZeroRoom air flow 158L/sAir change rate 10 per hour

En suite:- Pressure to room NegativeExtract air flow 45 - 158L/sAir change rate min 10 per hour


How robust is the concept?

What is the consequence of failure?Is the patient safe?Are the staff safe?

1. Extract fails; Supply maintained2. Supply fails; Extract maintained3. Both supply and extract fail


Corridor

En suite

Lobby

E

Staff door

S

Transfergrille

Pressurestabiliser

View panel


+ve

-ve

Neutral E

S

EE


HBN 4; Supplement 1Isolation facilities in acute settings


Isolation Suite Design

Historical perspective

Conclusions following outbreaks / incidentsLaboratory experimentsSmall scale modelsLidwells particle distribution work (KI discus)

The need for a more scientific approach!


NHS Estates / Department of HealthIsolation Suite Research Project

Research contract awarded to the Building Services Research & Information Association (BSRIA) Bracknell

Full size isolation suite constructed• Side room with Lobby and En suite

Test programme partners recruited• Frimley Park Hospital - Doors, Lights, Furniture• APRECO – Pressure stabilisers• GRADA – Air terminals and Transfer grilles


New build ward isolation roomSuggested design – HBN 4; Supp 1.


DH Isolation room research projectTest Programme

Air velocity and flow measurement• Velocity, Temperature, Noise

Flow visualisation using smoke• Gross air direction• Point air direction

Dilution control using tracer gas• Nitrous oxide and “sniffer” array around doors

Computed Fluid Dynamic Modelling (CFD)• Model to be calibrated to match the “real” data!


CFD Prediction of supply air jet


Physical measurement of supply air jet


DH Isolation room Research ProjectProgramme

Check the practicality of constructionTest the commissioning protocolProve the neutral pressure room conceptDefine the ventilation performanceOpen days for feedback and outside opinionDetermine the level of protection offeredExperiment to find the design limitsQuestion:- Is this a truly universal solution?

Thank You

Malcolm Thomas01132 582788

ward isolation suite basic concepts and research … · isolation suite research project ¾research...

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