Laser and operating room safety

Laser accidents—they do happen!

LASER AND OPERATING ROOM SAFETY

Dr. Meenu ChadhaChief Anaesthetist, Pain Physician and

O.T. Superintendent. Vishesh Hospital


LASER ACCIDENTS....THEY DO HAPPEN!Laser light differs from ordinary light in three waysDirectionalityMonochromaticityCoherence

Lasers can pose more of a hazard than ordinary light because they can focus a lot of power onto a small area


LASER TYPESCONTINOUS WAVE- Operates with stable beam power

( power remains constant)

PULSED OR Q- SWITCHED- Where pulse is generated by the resonant mode of the optical cavity. Power fluctuates up and down.


LASER CLASSIFICATIONOLD- American- Used before 2002 REVISED- European- from 2007

Class 1- Safe under all conditions of normal use

Class 1 M- Safe for all conditions except when passed through magnifying optics like telescope or microscope

Class I Laser

Product

Laser radiation Do not view directly with optical

instrumentsClass I M Laser product


Class 2- Safe because the blink reflex will limit the exposure to no more than 0.25 seconds. It only applies to visible light lasers.

Class 2 M- Safe because of the blink reflex if not viewed through optical instruments.

Class 3 R- Safe if handled carefully , with restricted beam viewing.

.

Laser radiation Do not stare into beamClass 2 Laser Product

Laser radiationDo not stare into beam or view directly with optical

instrumentsClass 2 M Laser Product

Laser radiationAvoid direct eye exposureClass 3 R Laser product


Class 3 B- Hazardous if the eye is exposed directly , but diffuse reflections are not hazardous. Protective eyewear required when direct viewing. Must be equipped with key switch and safety interlock

Class 4- Includes all lasers with beam power greater than 3 B. It can burn skin and cause permanent eye damage. Can ignite combustible material so fire risk. Must be equipped with key switch and safety interlock.

Laser radiationAvoid exposure to beamClass 3 B Laser product

Laser radiationAvoid eye or skin exposure to direct or scattered

radiation Class 4 Laser Product


LASER SAFETYThe most prominent safety concern with lasers is the possibility

of damage from exposure to the laser beam. The nature of the damage and the threshold level at which each type of injury can occur depend on the beam parameters:

Wave lengthBeam divergenceExposure duration

For pulsed lasers parameters includePulse lengthPulse repetition frequency


BASIC LASER SAFETY- EXPOSURE

MPE (Maximum Permissible Exposure)The highest laser energy exposure for eye or skin for a given

laser that will not cause injury

NHZ (Nominal Hazard Zone)Area within which the MPE can be met or exceeded


BEAM HAZARDSPrimary sites of damageEyesSkin

Laser beam damage can beThermal (Heat)AcousticPhotochemical


Many people think that looking into a laser beam can make them blind. Is that correct?

This fibroma was removed with a 15 wattsurgical CO2 laser, 50 mm focal length.

Can that laser make you blind? NO It might burn the cornea in or near the focal area, but not make someone blind!


An Alexandritelaser for hair removal.Can this laser make you blind?

NO

A Q-switched Nd:YAG-laser – can it make youblind if someone shoots right into your eyes?

NO


Lasers are of extremely low risk compared to: Dart arrows.Air guns.Knives.Stones thrown.Slingshots.Practically all weapons.Broken branches on trees in the forest.

Let us forbid all these things before putting strongrestrictions on therapeutic (and surgical) lasers


Lasers are used for eye treatments It is not "laser" light that may be dangerous.

It is any light of certain power, and exposure time, in certain wavelength interval, with certain pulse energy (if pulsed) with certain geometric configuration (divergence, solid angle) etc that may cause such irradiation in the retina that the MPE (maximum permissible exposure) is exceeded enough.


What is the best protection?Knowledge.Safety glasses can be hazardous: If you use the wrong type, you may think that you are protected, but instead ...


LASER SAFETY- CHOOSING THE CORRECT GLASSESThe safety glasses you wear depend on the type of laser you work

with and your processes.

Your glasses need to block all the wavelengths in use.

The optical density of your glasses should block the maximum power in use especially for invisible wavelengths.

The optical density and the wavelength must be printed on the glasses .

Just because it is the right color does not mean it will stop the laser.


FACTORS TO CONSIDER WHEN CHOOSING LASER EYEWEAR Rx – availability

Peripheral vision

Anti-fog capabilities esp. goggles

Multi wavelength operations , flip options

Laser inscribed markings

UV inhibitors to prevent darkening

Cost ( What’s the cost of an eye)

Inspect eyewear for pitting, cracking, scratches and discoloration including light leaks and coating damage prior to EVERY use


POLYMER LASER EYEWEARTranslucent laser resistant gogglesPassed UV and environmental stabilization tests. Lenses will not darken over timeSpecial caution- UV and CO2 – street wear lenses don’t

absorb these wavelengths


GLASS LASER EYEWEARNot as impact resistant as polymer, but do

not scratch easily.Heavier weight , limited frames.Glass prescriptions available.Made of mineral glass, dielectrically coated

mineral glass, layered laminates of mineral glass, rare earth minerals.

Flips in glass base, plastic flip down or plastic combo.


PATIENT EYE CARE OPTIONS

Gauze, cotton ball, tapes and quarters- looks cheap to patient and doctors.

Metal eye shields, extra ocular and intraocular corneal shields.

Disposable patient shields.

Laser glasses


EYE SAFETYAvoid “eye level” beamsAvoid situations where the beam is, or might be deflected upward i.e. beam

steering, “flippers,” periscopes.Use beam blocks . Keep the room lights bright if possible Remove or cover all jewelleryExercise caution when leaning down to beam-levelAlways look away from table area when bending-downThink twice before leaning to table level to get a better look at your

experimentBe VERY CAUTIOUS using “IR cards” and Ultraviolet (UV) Sensor

Cards


SKIN AND PHOTOCHEMICAL THERMAL BURNS

Ultraviolet (UV)- –UV can cause skin injuries comparable to a sun burnAs with damage from the sun, there is an increased risk

for developing skin cancer from UV laser exposure.Thermal InjuriesHigh powered (Class 4) lasers, can burn the skin and

even infrared (IR) and visible range cause first, second, and third degree of sun burns and can set clothes on fire.


PHOTOCHEMICAL AND THERMAL BURNS

Thermal Skin Burns-Rare; normally requires high exposure dose of at least several J/cm2; most common from CO2,10.6 μm exposure.

First degree (erythema), second degree (blistering), and third degree (charring) burns are possible-dependent upon exposure dose.

Delayed effects include skin cancer and accelerated skin aging

The hazards associated with skin exposure are of lessimportance than eye hazards. However, with the expandinguse of higher power laser systems, particularly ultravioletlasers, the unprotected skin of personnel may be exposed toextremely hazardous levels of the beam power if used in an unenclosed system design.


INTRAOPERATIVE PRECAUTIONS Dry combustible items as sponge, towel should not be placed

in sterile fieldSponges should be moistened and its moisture level should be

monitoredCloth and paper drapes not used because flammable,

polypropylene drapes least inflammable.Inflammable solutions not used for preparationIf laser surgery near patient’s teeth such as MLS, teeth

protector which is non inflammable and can withstand laser impact used.


INTRAOPERATIVE PRECAUTIONS Patient should receive preoperative instructions not to use hair

spray, gel or mousse.

If patients hair near laser impact site, covered with wet sponge.

Coat any exposed facial hair with water soluble jelly.

Laser personnel should wear scrub suits, gloves and surgical gowns to protect the skin.


COMMONLY OCCURING CAUSES OF LASER RELATED INCIDENTSUnanticipated eye exposure during alignments.

Available laser eye protection not used.

Intentional exposure occurred to protected persons.

Incorrect eyewear selection and/or eyewear failure.

Accidental eye/skin exposure during use.

Eye /skin hazards were produced of a photochemical origin.

BASIC LASER SAFETY CONTROLS

Administrative ControlsWarning SignsLabelsSOPs- Class 3B and 4

laser systemsTrainingSecurity

Engineering ControlsBeam HousingsShuttersAttenuatorsRemote viewing devicesInterlocks/switch lock

receptaclesEmergency Disconnects


OUT DOOR WARNING SYSTEMS

Warning sign which states type and wattage of laserAppropriate goggles for the specific wavelength of laser in use

to be located outside the door Door knob

warning signs ( “ Do not enter”, “ Alignment in progress”, “ Laser operating inside”) should be temporarily posted to alert the persons during beam alignment

TEMPORARY LASER CONTROLLED AREA ( e.g. Servicing Laser)

If a temporary laser controlled area is established, as in the case of servicing a laser a notice sign for temporary laser controlled area must be posted.

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WINDOW COVERINGNo additional covering required for CO2 laser – absorbed

by glassFor argon and Nd YAG laser- windows covered with

window inserts


ELECTRICAL CONNECTIONSDO NOT USEFrayed electrical cords .

If significant leak in water hoses.

Water leakage from laser console.

Isolated transformer alarms.

Excessive cords or wires on floor ( trip hazard)


ESSENTIAL REQUIREMENTSPOWER OUTLET REQUIREMENTSNd YAG- 208 volts , 3 phaseArgon -208 volts, single phaseCO2 110 volts grounded

WATER SAFETYIf water leakage- disconnectPerson should stand on dry floor when plugging the laserLaser foot pedal on dry floor. Only one foot pedal is to be used.Instruments to be used in laser proximity have dull rough surface to diffuse

any stray energy or constructed of material that will absorb energy


SMOKE EVACUATIONSome procedures generate smoke so smoke evacuation requiredHigh filtration surgical masks must be worn during procedures that

produce plumes.Fire extinguisher must be always availableContainer of sterile water always availableDo not use flammable tapes, skin degreasers, prep solution,

lubricants and drying agents during surgeryPVC endotracheal tubes not suitableCover rectal area with moist sponges as methane gas is inflammableUse non-explosive anaesthetics and localized ventilation in laser

surgery of digestive tractsAvoid flammable gases near laser

DEFECTIVE

DO NOT USE

Date ___________By ___________

Do not RemoveThis Label

LOCK OUT/ TAG OUT PROCEDURES

Laser systems have safety concerns.

Ensures that the equipment being controlled cannot be re- energized until the locking device is removed


ENTRY WAY CONTROLSOf two typesDoors and barriers that are interlocked to laser power supplyDoors and barriers that are not interlocked to laser power

supply.

First option best and provision can be made for selective entry of personnel


BEAM PATH CONTROLDone to reduce the nominal hazard zone around the laser

Use of a mechanically stable , optical table.Careful placement of optical components to ensure the beam

path is well defined.Keeping the beam path above or below the eye level.Use of screens , curtains, window cover.


COLLATERAL RADIATIONIncludes any radiation produced by the laser or laser system other

than the beam

X ray radiation- lead shielding is required to keep the exposure below the maximum permissible exposure level.

Ultraviolet and visible radiation- Protection afforded by protective housing over laser


PANIC BUTTONRed mushroom shaped button – to facilitate immediate

shutdown of a laser in an event of emergency such as fire or sudden or unexpected change in beam direction that creates a hazard to personnel


EMERGENCY PROCEDURESMay be sudden fire, explosion, release of toxic gas or serious

injury to personnel

Shut the laser off using panic button or remove the interlock key

Evacuate the areaIf fire- evacuate and shout FIRE, activate fire alarm


TRAININGLaser education program should be designed to meet

individual’s needOT personnel should demonstrate appropriate skill levels

before assuming the responsibility for operating laser equipment.

Laser safety operator should be responsible for1. Laser safety protocol2. Performing laser equipment preoperative check3. Operating laser control panel4. Completing laser documents


SPECIFIC PROCEDURESLASER SURGERY IN HEAD AND NECK AREA

CO2 LASER- For patient- if patient asleep- saline soaked sponges over patients eyes and if awake protective goggles.

For OT personnel – clear goggles over prescription glasses , clear glasses with side shields, contact lenses not acceptable


Nd YAG OR ARGON LASERFor treatment outside eye area- eyes covered with oval gauze and

overlying filtering lenses that correspond to the specific laser wavelength. Both should be taped securely so no exposed area through which light can radiate. If patient awake –protective goggles.

For treatment of periorbital area- eye can be protected by holding a covered or dull metal spoon over the eye, to expose more skin surface for treatment.

For OT personnel- For argon- Special eyewear with OD> 5, amber filtered goggles with side shields

For Nd YAG- Special eyewear OD 4.5, green filtered goggles with side shields.


SURGERY BELOW HEAD AND NECK Patients who are awake- Goggles provided so there is no open

area between the goggle and skin surface where laser light may enter. Or patients may wear a sleep mask with gauze pads placed between the mask and face.

Patients who are asleep- gauze pads taped securely over the eyes.


EYE WEAR FOR OT PERSONNEL For diode- Special eyewear with OD 4

When using laser through endoscope or microscope- all OT personnel should wear appropriate eye wear and endoscopic lens covers with appropriate filtering lenses must be used for protection.


SAFETY CHECK LIST

PREOPERATIVE1. EYE PROTECTION- Personnel, patient

2. DOORS PROPER WARNING SIGN- Flashing light on

3. SMOKE EVACUATION

4. FIRE EXTINGUISHER- Room free of inflammables, patient free of inflammables- hairspray, clothing etc

5. WATER- Laser hoses connected to outlets and turned ON. Excessive water not leaking from hoses.


6. ELECTRICITY- Electric cords are in good condition, cords plugged into appropriate outlet, circuit breaker switch in correct position.

7. TRAFFIC- Laser console, water hoses, and electrical cords are out of traffic mainstream.

8. GASES- coaxial –proper kind and amount for laser. Assist for CO2 LASER, co2 for CO2 laser enough for procedure.

9. RECIRCULATION SYSTEM- Off and on as needed, High and low flows regulated, Suction regulated, Endoscope T piece ready for use,


10. DELIVERY SYSTEM INSPECTION/PLACEMENT- Fibre, Hand piece, Micromanipulator.

11. MODIFIED INSTUMENTATION- Retractors, suction, special finish on instruments, modified endotracheal tubes, modified cottonoids.

12. REINTUBATION EQUIPMENT- ready

13. OBATIN KEY TO LASER

14. BASIN OF STERILE WATER AVAILBLE

15. TEST FIRE LASER

16. CHECK LASER FOR PROPER FUNCTIONING- Check standby/ OFF, check HIGH/LOW laser power, check all mode and malfunction panels


INTRAOPERATIVE

1. When physician requests laser , turn machine to standby and position foot pedal for physician.

2. Select mode and power as requested by physician

3. Do not leave laser while in use.

4. Place laser on standby when not in use

5. Turn off the laser before changing gas tanks.

6. Maintain communication with surgeon while operating the laser.


POSTOPERATIVE1. Turn of laser and remove the key.

2. Return laser key to proper storage.


CONCLUSIONSafety is everyone’s responsibility !

Knowledge of Laser science= Ability to perform risk assessment=development of appropriate safety policies=safer staff=safer patient care !!!

Laser and operating room safety

Health & Medicine

Transcript of Laser and operating room safety