VENTILATION SYSTEMS AND THERMAL CONDITIONS IN

OPERATING ROOMSMettere il nome di chi presenta

Control of the asepsis level

Control of the concentration of any form of pollutants:

chemical (anaesthetic gas and volatile substances)physical (particulate and aerosol)

micro-biological (pathogenic agents related to the human presence, to the surgical interventions themselves and to the spores carried on by the airborne particulate).

Rising trends in surgical activities:

The needs:to assure values of the air quality not dangerous for the health of the operators;to contain the infection risks.

Hospital infections in Italy:

Over 500.000 cases a year (30.000 deaths) on 9,5 million patients (30-35% related to the operating site);Over 1,5 million €/year for medical treatments;An expected loss of 3 million of working days.

The cost of a sepsis of small entity, caught in the operating room, is about € 3.500 ÷ € 7.000 at expense of the hospital structure.The cost of a deep sepsis is up to € 20.000 ÷ € 25.000.

In some countries the insurance companies don't cover the deep sepsis as imputed to a bad hospital management.

The Aim of the Research is to assess :

the genesis of the pollution phenomena in operating rooms;the correlations among the boundary conditions (room’s technological state, type of surgical operation, people in the room, clothing, clinical frame of the patient, etc.).

The research is carried out both within four surgical rooms at the Cento Hospital (Ferrara, Italy) (general surgery, urology/gynecology, emergency and orthopedics) and within the CERTECA (Air Technologies Researches Centre) Laboratory of the Ferrara University.

Cento Hospital

Operating Rooms at Cento Hospital:HVAC Plants

CERTECA(Air Technologies Researches Centre)

The CERTECA Test Facility reproduces a real operating room, with all the equipments, HVAC plant and control systems able to reproduce different conditions of ventilation and pollution.

CERTECA CENTRE:HVAC Plants

1. Containing in-field sensitive data (implemented on a server at the hospital and not directly accessible to the researchers)

2. Containing all the data of scientific interest (implemented on aserver at the University of Ferrara)

3. Containing the experimental data of contamination, decontamination, efficiency and effectiveness of ventilation tests carried out in the same room under the different conditions of operation.

Data are collected on

three databases:

12

3

The Automatic Data Acquisition Systems performs the followings functions:

- identification of the patient going into the operating room (RFID)

- identification of the personnel present in the room (RFID)

- time schedule of the surgical operation (RFID)

- identification of the surgical irons set (RFID)

- assessment of the successful sterilization of the irons set (RFID)

- identification of the of anaesthetic infusion (Palm-PC)

- identification of the surgical intervention (Palm-PC)

- identification of the used prostheses (Palm-PC + bar code)

The final aim is to build a computerized clinical report

Microbiological pollution(Petri Plates, S.A.S.)

Physical Pollution (Kanomax)

Environmental Comfort (Babuc A)

Air Flow Control (Balometer, Ultrasonic Anemometer)

Microbiological and Microbiological and EnvironmentalEnvironmentalMonitoringMonitoring

Measuring campaigns have been performed either with the operating room “at rest” or “in operating”

• Petri Plates

• S.A.S

Babuc A

• Kanomax

Instrumentation Layout

Orthopaedics RoomSurface: 36 m2

Ventilation Plant: turbulent flow (22 air changes/hour) absolutedouble filtering.

Microbiological Measurements:

1. Passive instruments (Petri plates)

2. Active equipment (SAS instrument).

Microbiological Monitoring

Passive Air Passive Air SamplingSampling

Data Data collectedcollected in in OrthopaedicOrthopaedic Room Room at at restrestand and in in operatingoperating

Plates Plates incubatedincubated at 37at 37°°C C for 48 hoursfor 48 hours

NumberNumber of CFU of CFU verifiedverified

ActiveActive Air Air SamplingSampling

SurfaceSurface air air samplersampler (SAS(SAS--PBI PBI InternationalInternational))

A known volume (6000 l/h) of air A known volume (6000 l/h) of air isisblownblown ontoonto Agar Agar CleanClean Room Room Contact FDA (55 mm) Contact FDA (55 mm) plateplate

SAS SAS waswas positionedpositioned on on toto harmharm--shelfshelf (1m (1m awayaway fromfrom the the operatingoperatingbedbed) )

PlatesPlates werewere incubatedincubated at 37at 37°°C C forfor48 48 hourshours

Data Data collectedcollected in in OrthopaedicOrthopaedicRoom Room at at restrest and and in in operatingoperating

Physical and Environmental Monitoring1. Babuc A data acquisition

system

2. Kanomax Geo-α particulate meter

BABUC A PSYCHROMETRIC PROBE GLOBOTHERMOMETRIC PROBE ANEMOMETRIC PROBE

Following the ISO 14644 Rules for the white rooms and other sterile environments, the measurements of the airborne particulate (0.3 µm , 0.5 µm, 1 µm, 3 µm e 5 µm) have been performed in correspondence at 6 points.

Physical Pollution

2m2m

A

C

E F

B

D

Door

10 min, 20 min, and 30 min tests have been performed for setting up the optimal sampling time allowing the ventilation plant to effect a sufficient number of air exchanges without intervention by the operators.

- Operating room at rest - Kanomax Geo-α with sampling flow

of 2.8 l/min.

The result of tests show that the minimum sampling time for attaining the asymptotic value is 30 min.

Concentrazione polveri sala ortopedia 12 marzo 2005

condizione at rest - punto A

0.0E+00

5.0E+04

1.0E+05

1.5E+05

2.0E+05

2.5E+05

3.0E+05

3.5E+05

4.0E+05

9.05 9.08 9.11 9.14 9.17 9.20 9.23 9.25 9.28 9.31 9.34 9.37 9.40 9.43

ora

parti

celle

/m3

0.3 micron0.5 micron1 micron3 micron5 micron

March 12th 2005

Point A – Room at rest

Hours

ROOM AT REST

The distribution of the concentration (ten minutes averaged values) depends on the position of the sampling point:- A = 400.000 part/m3

- B = 50.000 part/m3

- C, D, E, F = near to the asymptotic value since the beginning.

The doors operation influences the concentration level at the nearest points (A and B). Door opens from left to right, the left part of the room (A) remains exposed for more time.

0

500

1000

1500

2000

2500

3000

3500

part

icel

le/m

3

A B C D E Fpunto di rilievo

Concentrazione media sala ortopedia 12 marzo 2005 - condizione at rest

0.3 micron0.5 micron1 micron3 micron5 micron

March 12th 2005

Room at rest

The results of the measurements allow us to classify the orthopaedic room as ISO 5 class (ISO 14644 Rules) at rest .

1.00E+001.00E+003.64E+011.42E+029.91E+02F

3.64E+013.64E+011.07E+022.84E+021.73E+03E

1.00E+001.00E+001.00E+003.64E+012.09E+03D

1.00E+001.00E+001.00E+001.00E+009.55E+02C

3.64E+013.64E+013.64E+011.43E+021.66E+03B

1.07E+022.49E+024.60E+021.13E+033.43E+03A

5 µm3 µm1 µm0.5 µm0.3 µm

Concentration (particle/m3)point

Mean Values in orthopaedics room at rest – 12/03/2005

5.04.13.94.2CLASS

5 µm1 µm0.5 µm0.3 µmdiameter

N = log (Cn) - 2,08·log (0.1/D)N

Particle diameter considererD

number of particle / m3Cn

Classification ISO orthopaedics theatre

ROOM IN OPERATING

The time course of the concentration is similar for all the particles, the difference among the values is sensible to the diameter of the particles.

Notable differences arise among the various intervention typologies or among episodes occurring in the same operation

Misura micropolveri1 Marzo 2005 - Ortopedia

0,E+00

1,E+06

2,E+06

3,E+06

4,E+06

5,E+06

6,E+06

7,E+06

7.58 8.26 8.55 9.24 9.53 10.22 10.50 11.19 11.48 12.17 12.46 13.14 13.43 14.12

orario

part

icel

le/m

3

0,E+00

1,E+07

2,E+07

3,E+07

4,E+07

5,E+07

6,E+07

7,E+07

part

icel

le/m

3

(0.3

mic

ron)

0.5 micron1 micron3 micron5 micron0.3 micron

ATA

artroscopia spalla

osteosintesi(raggi+tecnico)

pulizia OR

Misura concentrazione polveri sala di ortopedia 28 febbraio 2005 - condizione operating

0,0E+00

5,0E+05

1,0E+06

1,5E+06

2,0E+06

2,5E+06

3,0E+06

3,5E+06

4,0E+06

9.50 10.19 10.48 11.16 11.45 12.14 12.43 13.12 13.40ora

part

icel

le/m

3

0,0E+00

5,0E+06

1,0E+07

1,5E+07

2,0E+07

2,5E+07

3,0E+07

3,5E+07

4,0E+07

part

icel

le/m

3

(0,3

mic

ron)

0.5 micron1 micron3 micron5 micron0.3 micron

asportazione ernia disco ricostruzione apparato

estensore

realizzazione ginocchiera in gesso

artroscopia con artrite

notably higher values during the reconstruction of the extensor apparatus than those referring to the arthroscopy

remarkable peak of concentration corresponding to the realization of a plaster knee-guard.

ENVIRONMENTAL COMFORT

Thermal comfort conditions in the operating room: a very complex problem.

It is necessary to conciliate several requirements:

homothermic conditions of the patient, avoiding the risk of Hypothermiacomfort conditions of the components of the surgical team

Incorrect micro-climatic conditions can also affect the airborne microbiological components promoting the development and the growth of bacterial colonies.

The aim of the study is to verify the correlation among the two different techniques of investigation:

the first (objective): the acquisition of the most important parameters related to the environment, the medical operators and the patient

the second (subjective): the gathering of the judgments expressed by all the presents towards the environment

The latter objective can be reached by means of a questionnaire regarding the feelings of comfort or uneasiness, the clothing, the weight, the age, the activity level, etc.

The microclimatics parameters, the clothing characteristics and the activity level, allow to elaborate the Fanger’s indices of thermal comfort:

Predicted Mean Vote (PMV)Predicted Percentage of Dissatisfied (PPD).

The measures have been performed placing the equipment in the center of the room at a height of 1,5 meters, with the scialytic lamp both turned on and off, with the room both “at rest” and “in operating”

The results of this investigation conducted either in field or in simulated environment will allow us to set an investigation methodology and a measuring protocol aimed to the identification of new indices of thermal stress specific for theenvironment that is the object of our study.

At rest

In operating

Control of ventilation rates

Perodically the flow rates at the air intakes are checkedusing an AIRDATA Shortridge-ADM-850L balometer.

The air flow distribution isalso verified by using a Thies Bi-axial UltrasonicGonioanemometer

G. Lupo

Dipartimento di Ingegneria CivileUniversità degli Studi di MessinaContrada di Dio - S. Agata Messina (Italy)Tel 090 3977308 - Fax 090 3976474 e-mail: gio.lupo@email.it

Università degli Studi di FerraraFACOLTA’ DI ARCHITETTURA                       

Università degli Studi di Palermo FACOLTA’ DI INGEGNERIA

Università degli Studi di MessinaFACOLTA’ DI INGEGNERIA

S. MazzacaneDipartimento di ArchitetturaUniversità degli Studi di FerraraVia Quartieri 8 44100 Ferrara (Italy)

tel +39-0532-29.36.46fax +39-0532-29.36.27email mzs@unife.it

C. Giaconia; S. Costanzo; A. Cusumano

Dipartimento di Ricerche Energetiche ed AmbientaliUniversità degli Studi di PalermoViale delle Scienze 90128 Palermo (Italy)Tel. +39-091-236213Fax +39-091-484425email giaconia@unipa.it