nosocomial infection ----prevention and control

Nosocomial Infection ----Prevention and control

Wang kefang （王克芳）[email protected]

下列物品或情形该怎样处理？体温计需要消毒吗？该怎样处理？你发现手上扎了一根小刺，同学找来缝衣针要给你

挑出来，这根缝衣针可以直接用吗？你从商店里买来一件 T 恤衫，你穿之前处理吗？有个亲戚在你家吃住 2 天，他走后你想消毒一下餐

具和被褥，如何做？

2 Cleaning, Disinfection and Sterilization

ConceptsCleaning （清洁）Disinfection （消毒）Sterilization （灭菌）

ConceptsCleaning Cleaning is to remove the dirt from item surface by

the use of water, detergents and mechanical actions.

Will remove most organisms from a surface. Remove not kill ！！！

ConceptsCleaning

Disinfection A process that eliminates/kills almost all pathogens on

objects, except of bacterial spores, to decrease the number of them to a harmless level.

ConceptsCleaning

Disinfection

Sterilization A process that destroys all forms of microorganisms,

including bacterial spores

Decontamination Steps

Levels of disinfection and sterilization

Level Bacteria Fungi ( 真菌 )

Viruses

Lipid Nonlipid

Vegetative Tubercle bacilli

Spores

sterilization ﹢ ﹢ ﹢ ﹢ ﹢ ﹢HLD ﹢ ﹢ ± ﹢ ﹢ ﹢ ILD ﹢ ﹢ ﹣ ﹢ ﹢ ± LLD ﹢ ﹣ ﹣ ﹣ ﹢ ﹣

Low-level disinfection (LLD) ,Intermediate-level disinfection (ILD),High-level disinfection (HLD)

Items’ risk to patients High risk(critical) items

Intermediate risk (semi-critical) items

Low risk (noncritical) items

How to select disinfection and sterilization


Items that reach the sterile tissues or organs( such as

body cavities and the vascular system).

Items: Surgical instruments, syringes

Items should be sterilized before using



Intermediate risk (semi-critical) items Items that do not enter sterile areas of the body but

contact with mucous membranes or skin closely. Items: thermometer, ventilator tube HLD/ILD, Sterilization is preferred.



Intermediate risk (semi-critical) items

Low risk (noncritical) items Items that contact with intact skin, not mucous

membranes Items: gown, sheet, blood pressure cuff LLD (in some cases, cleaning is acceptable)


Items’ risk to patients Characters of contaminated microorganisms

种类、数量、对消毒因子的敏感性致病性芽胞、真菌孢子—灭菌、高水平消毒致病性细菌、真菌、亲水病毒、支原体、衣原体—中水平以上消毒一般细菌和亲脂病毒—中水平和低水平消毒


Items’ risk to patients Characters of contaminated microorganisms

Characters of items耐热、耐湿物品和器材，应首选压力蒸汽灭菌法耐高温的玻璃器材、油剂类和干粉类可选用干热灭菌怕热、忌湿和贵重物品，可选择甲醛或环氧乙烷气体金属器械的浸泡灭菌，应选择腐蚀性小的灭菌剂在进行物品表面消毒时，应考虑到表面性质

表面光滑—紫外线；多孔材料—喷雾


Methods of Disinfection and Sterilization

Physical Methods

Chemical Methods:

Heat

Microwave

Ionizing radiation

Radiation

Mechanical removing microorganisms

Dry heat ：

Moist heat:

Boiling

Steam Disinfection

Low Temperature Steam Disinfection

High-Pressure Steam SterilizationSunshine

Ultraviolet light

ozone

Immersion; Rubbing; Nebulization; Fumigation

burning 、 toasting

Physical Methods

High-Pressure Steam Sterilization

SterilizationSterilization

the most common and effective method Advantages:

Highly effective; Rapid heating and rapid penetration of items; Nontoxic; Inexpensive;

用途 : 常用于 : 耐高温、耐高压、耐潮湿物品的灭菌 ---- 金属、玻璃、橡胶、搪瓷、敷料等不能用于凡士林等油剂、滑石粉等粉剂的灭菌

Sterilization parameters


Sterilizers Pressure Temperature Time

下排气式灭菌器 103kPa 121ºC 20-30 min

预真空灭菌器 205kPa 132ºC 5-10 min

Physical Methods

High-Pressure Steam Sterilization

Notes: Clean and dry items Package size：下排气式 30 ×30 × 25cm；预真空式 30 ×30 × 50cm

Arrange all packages in a way that allows the steam to circulate freely.

Timing until the autoclave reaches the required temperature and pressure.

Follow the instruction for operating the autoclave. Packs should NOT be pick out of the autoclave until dry. Label accurately with contents, date of processing and

expiration and store in storage cabinet. Monitor the effectiveness of sterilization


Monitoring the Effectiveness

IndicatiorsIndicatiors

Mechanical indicators

Chemical indicators

Biological indicators

Mechanical Indicators

These indicators, which are part of the autoclave or dry-heat oven itself, record and allow you to observe time, temperature, and/or pressure readings during the sterilization cycle.

IndicatorsIndicators

Chemical Indicators

Each pack must have external chemical indicators.

Indicator strips will change color when temperature, time, and pressure has been achieved.


Biological Indicators

非致病性嗜热脂肪肝菌芽孢 .

If the bacterial spores have been killed after sterilization, you can assume that all microorganisms have been killed as well.

Advantages: It directly measures the effectiveness of

sterilization. Disadvantages:

This indicator is not immediate. Bacterial culture results are needed before sterilization effectiveness can be determined.


Toasting Sterilization (Hot Air Oven) 用途 :

适用于在高温下不变形、不损坏、不蒸发的物品：glass, metal instruments, oil, ointments and powders

不适用于纤维织物、塑料制品等的灭菌。

灭菌参数： 160 ºC, 2 hours; 170 ºC, 1 hour; 180 ºC, 0.5 hour.


Physical Methods

Notes:

Clean and dry all items to be sterilized.

Package size ： 10cm×10cm×20cm.

Organic items ： temperature no more than 170℃


Other Physical Methods

Disinfection by Boiling

Ultraviolet Light Radiation

Microwave Disinfection

High Level DisinfectionHigh Level Disinfection

Boiling For items which are resistant to moisture and

high temperature, such as mental, glass, rubber.


Notes: Clean Open all hinged instruments and other items.

Catheter should be filled with water. Make sure that all items are completely submerged because water must touch all surfaces.

Once the water is in a rolling boil, start timing for 5-15 minute. From this point on do not add or remove any water or items.

Notes:

A 1-2% solution of sodium bicarbonate( 碳酸氢钠 ) rises the boiled temperature to 105 and helps to ℃prevent corrosion of the instruments.

The boiling point of water is affected by air pressure. Generally, every 300 meters is added, disinfection time should be prolonged for 2 minutes.

Never leave boiled items in water that has stopped boiling; they can become contaminated as the water cools.


Air disinfection A 30W UV light for every 10 m2

The effective distance ：≤ 2 meters The radiation time ： 30-60 min.

Object surface disinfection The effective distance: 25-60 cm The radiation time ： 20-30min.

Fluid disinfection The fluid depth : ≤ 2 cm


Ultraviolet (UV) Light Radiation The best anti-bacterial effect: 250-270nm.

Notes: Keep UV light clean: alcohol cotton twice a week. Effective condition:

Temperature: 20-40 ºC Humidity: 40-60%

Record radiation time after the UV light has been on for 5-7 minutes.

When turned off, the light should be cooled off for 3-4 minutes before being turned on again

Regularly check the output of the UV light Intensity≤ 70µW/cm2 , change the light. Time ≥ 1000 hours, change the light.

Keep people off the room; cover eyes and skin if people couldn’t leave.


Microwave disinfection

Uses: food, tableware, medication and some heat-tolerant non-metal instruments.


Notes: Microwave is harmful to health, so avoid long term contact

in small dose or large dose. Microwave can not penetrate metal, do not put objects in

metal container. Water is a strong microwave absorbing medium, so wet

wrapped item or put a glass of water in the microwave oven can enhance disinfection efficacy.

Methods of Disinfection and Sterilization

Physical Methods

Chemical Methods: Immersion; Rubbing; Nebulization; Fumigation

Heat

Microwave

Ionizing radiation

Irradiation

Mechanical removing microorganisms

Dry heat ： burning 、 toasting

Moist heat:

Boiling

Steam Disinfection

Low Temperature Steam Disinfection

High-Pressure Steam SterilizationSunshine

Ultraviolet light

ozone

Chemical Methods

Sterilant A chemical agent that can destroys all forms of

microorganisms to achieve sterilization.

Disinfectant A chemical agent that destroys most pathogens

but may not kill bacterial spores.

Disinfectant/Sterilant

消毒灭菌水平、用法及浓度、注意事项 Glutaraldehyde （戊二醛） Chlorine disinfectant( 含氯消毒剂 )

Alcohol （乙醇） Iodophor （碘伏） Iodine tincture( 碘酊 )

Textbook p73 表 4-4

Levels of disinfection and sterilization

Levels Methods

Sterilization Heat/Microwave/Ionizing radiationGlutaraldehyde ( 戊二醛 )/formalin （福尔马林） /ethylene oxide （环氧乙烷） /peracetic acid （过氧乙酸）

High-level disinfectionUltraviolet light/ozone

Chlorine disinfectant （含氯消毒剂）

Intermediate-level

disinfection

Alcohol （乙醇） /Iodophor （碘伏） /Iodine tincture( 碘酊 )

Low-level disinfectionMechanical removing microorganisms季铵盐类 / 双胍类消毒剂

Principles for Chemical Sterilization/Disinfection

Before deciding to use a chemical method, consider whether a more appropriate physical method is available.

Select appropriate disinfectant and method according to the characteristics of items and microorganisms

Pay attention to the effective concentration of disinfectant and contact time

Make sure the solution is still effective when you use a previously prepared solution or a new solution.

Put it in a sterile container with a lid and mark the container with the preparation date and expiration date.

Do not put gauze, cotton in disinfectant.

妇儿医院手术切口分枝杆菌感染暴发（广东深圳， 1998）

表现： 1998年 4 月 1 日～ 5 月 31日共手术 292例， 4 月 22日～ 7 月 14日发生切口感染 166例。

调查： 20份切口分泌物标本培养出分支杆菌（脓肿亚型）。使用中和未启用的戊二醛半小时不能杀灭金葡菌、 1 小时不能杀灭分支杆菌，测浓度为 0.137%。

结论：戊二醛浓度错配导致手术器械分支杆菌污染，从而引起切口感染

Principles for Chemical Sterilization/Disinfection

Before deciding to use a chemical method, consider whether a more appropriate physical method is available.

Select appropriate disinfectant and method according to the characteristics of items and microorganisms

Pay attention to the effective concentration of disinfectant and contact time

Clean, and dry all items to be sterilized /disinfected. Maintain enough contact time for items with disinfectant

solution Rinse thoroughly with sterile/clean saline to remove the

residue that is left on items. This residue is toxic to skin and to tissues.

Common methods

浸泡法（ immersion ）

擦拭法 (rubbing)

喷雾法 (nebulization)

熏蒸法 (fumigation)

Immersion

Open all hinged instruments and other items.

Place all items in the solution so that they are

completely submerged.

应用范围耐湿不耐热的器械物品如锐利器械（刀剪）、贵重仪器（导管、胃镜等）、塑料

尼龙制品等

Rubbing

应用范围擦拭被污染物体的表面或皮肤、黏膜

选用：易溶于水、穿透力强、无显著刺激的消毒剂如用含氯消毒剂擦拭墙壁、地面

Nebulization

用喷雾器将消毒剂均匀地喷洒于空气或物品表面进行消毒的方法。

常用于地面、墙壁、空气等的消毒。

Fumigation 将消毒剂加热或加入氧化剂，使其产生气体进行消

毒的方法。如手术室、换药室、病房的空气消毒。在消毒间或密闭的容器内，也可用熏蒸法对被污染的物品进行消毒灭菌。

常用的有甲醛气体和环氧乙烷气体。

Daily Cleaning, Disinfection and Sterilization in Hospital

Hospital environment

Preventive disinfection and disinfection of epidemic focus

Textiles and laundry

Skin and mucous membrane

Equipment, instruments/devices

Waste and sewage

Environmental ： Air Disinfection

Category Including Methods

I laminar flow operation room, laminar flow ward and sterile pharmaceutical preparation room, et al.

laminar flow

II operation room, obstetrical ward ， infant room, premature infant room, protective isolation room, burn ward, ICU, et al.

air disinfector

III common ward, examination room, injection room, emergency room, et al.

II methods

ozone, ultraviolet light, and chemical solution

IV contagious ward II and III methods

Environmental ： Surface Disinfection

Floor: If no obvious contamination, Wet cleaning. If contaminated by pathogenic microorganisms, use

chemical disinfectants to mop or spay the floor.

Wall: Do not need regular disinfection; if contaminated, use chemical disinfectants to spay or rub

the wall.

Object surfaces: Use clean cloth or cloth with disinfection solution to rub the

surfaces bed, bedside tables, chair, doorknob, windows, door and urinal.

If contaminated, use chemical disinfectant to spay or rub them, or use ultraviolet light.

Preventive Disinfection andDisinfection of Epidemic Focus

Preventive disinfection

Disinfection of epidemic focus Concurrent disinfection Terminal disinfection

Textiles and Laundry The textiles and laundry used by patients are

sterilized by ethylene oxide, then washed and prepared for use.

If there is no ethylene oxide sterilization room, use the following methods: wash and then disinfect patients’ cloth and sheet by high

temperature; use ultraviolet light to disinfect blankets, pillows, bed

mattress; wash and disinfect contagious patients’ and other patients’

textiles and laundry separately; wash and disinfect health care workers’ and patients’

textiles and laundry separately.

Skin and Mucous Membrane

Skin and mucous membrane provide protective barrier to microorganisms.

choose appropriate antiseptics according to patients’ skin and mucous membrane site, pathogenic microorganisms. Use 2% iodine tincture to disinfect skin, after dry deiodinize

it with 75% alcohol. Use 0.5%-2% iodophor.

Surveillance

Environmental air, object surfaces and HCW’s hands Equipment, instruments/devices Disinfection solution High pressure sterilization and ultraviolet light Dishware and eating utensils Sanitary utensils Drink water Textiles and laundry, medical waste Waste

教学内容清洁消毒灭菌概念消毒灭菌的方法医院清洁、消毒、

灭菌工作

教学目标解释术语：清洁、消毒、灭菌掌握常用物理消毒灭菌法的方

法和注意事项掌握常用化学消毒剂的名称、

浓度、使用注意事项

2 清洁、消毒、灭菌清洁、消毒、灭菌

Words:

Nosocomial Infection

Chain of Infection

Source of Infection

Mode of Transmission

Susceptible Host

Cleaning

Disinfection

Disinfectant

Sterilization

Sterilant

nosocomial infection ----prevention and control

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