WARD ISOLATION SUIT BASIC CONCPTS and RSARCH PROGRAMM Malcolm Thomas Consulting ngineer 01132 582788 March 2006
Isolation Fact and Fiction Isolation is required! When admitted, patients condition unknown Levels of protection:- 1. A closed door 2. Universal nursing precautions 3. Medication 4. Ventilation Complicated systems are unreliable Staff change; knowledge is lost 2
Single room xtract fan (Optional) Bed Window WC (Optional) View panel Doorway Corridor 3
Negative pressure isolation room with lobby WC Bed S Corridor View panel Bed door Lobby Staff door 4
Negative pressure isolation room with lobby WC Bed S Corridor View panel Bed door Lobby Staff door 5
Switchable airflow isolation room with lobby Bed Not Recommended! View panel S WC Lobby S Corridor Bed door Staff door 6
Summary of current UK situation Many different types of room installed On site staff knowledge poor Nursing states and Facilities Many rooms modified Do not work as intended Change of use 7
Types of Isolation Rooms Positive pressure room Transplant units / Chemotherapy Negative pressure room Infectious diseases units Switchable room (Positive / Negative) Wards / ITU / HDU Neutral pressure room with Ventilated lobby New concept Universal application? 8
Isolation room, en suite and ventilated lobby Locked / Sealed window Bed Transfer grille n suite View panel Pressure stabiliser Lobby S Corridor Access door 9
Isolation room, en suite and ventilated lobby (Schematic of alternative layout) Locked / Sealed window and Solid ceiling Transfer grille n suite Bed View panel Pressure stabiliser Lobby S Bed door Staff door 10
Isolation room Pressure and flow regime Locked / Sealed window and Solid ceiling n suite Bed Transfer grille Neutral 10 ac/h -ve; Min 10ac/h View panel Pressure stabiliser Lobby S +ve 10Pa Corridor Bed door Staff door 11
Isolation room, en suite and ventilated lobby Neutral Transfer grille n suite -ve View panel Pressure stabiliser Lobby S +ve Corridor Staff door 12
Nominal Ventilation Parameters Lobby:- Pressure to corridor 10 Pascals Supply air flow 208-238L/s Air change rate 63-69 per hour Isolation room:- Pressure to corridor Room air flow Air change rate n suite:- Pressure to room xtract air flow Air change rate Nominally Zero 158L/s 10 per hour Negative 45-158L/s min 10 per hour 13
How robust is the concept? What is the consequence of failure? Is the patient safe? Are the staff safe? 1. xtract fails; Supply maintained 2. Supply fails; xtract maintained 3. Both supply and extract fail 14
Isolation room, en suite and ventilated lobby Neutral Transfer grille n suite -ve View panel Pressure stabiliser Lobby S +ve Corridor Staff door 15
HBN 4; Supplement 1 Isolation facilities in acute settings 16
Isolation Suite Design Historical perspective Conclusions following outbreaks / incidents Laboratory experiments Small scale models Lidwells particle distribution work (KI discus) The need for a more scientific approach! 17
NHS states / Department of Health Isolation 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 n suite Test programme partners recruited Frimley Park Hospital - Doors, Lights, Furniture APRCO Pressure stabilisers GRADA Air terminals and Transfer grilles 18
New build ward isolation room Suggested design HBN 4; Supp 1. 19
DH Isolation room research project Test 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! 20
CFD Prediction of supply air jet 21
Physical measurement of supply air jet 22
DH Isolation room Research Project Programme Check the practicality of construction Test the commissioning protocol Prove the neutral pressure room concept Define the ventilation performance Open days for feedback and outside opinion Determine the level of protection offered xperiment to find the design limits Question:- Is this a truly universal solution? 23
Thank You Malcolm Thomas 01132 582788