slide presentation on occupational hazards of anesthesia with latest millers update

2. The Explosive History
 Historically, the greatest occupational hazard encountered by an anesthetist
was the threat of a fire or explosion while using a potentially explosive
anesthetic agent
 The first recorded fire resulting from the use of an anesthetic agent occurred
in 1850, when ether caught fire during a facial operation.
 Many subsequent fires and explosions have been reported ,caused by ether,
acetylene, ethylene and cyclopropane.
 But, replacement with non-explosive agents has rendered this hazard virtually
obsolete in modern anesthesia

3. Infection
 Blood-borne pathogens- HIV, Hepatitis B and C.
(self-inoculation from a needle during the insertion or suturing of intravascular catheters, the injection of
intradermal anesthesia)
 Air born pathogens- Tuberculosis,Covid-19,SARS
(Suction,Intubation,Tracheostomy)
 Exposure to body fluids other than blood- Amniotic fluid, CSF, Pericardial fluid, Pleural fluid,
exudative fluid from burns or skin lesions.

4. Hepatitis B
 Highly infectious and the risk of transmission after occupational exposure is higher than for HIV.
 In a multicenter study, the overall prevalence of serologic indicators for HBV in anesthesiology residents
who had received neither hepatitis vaccine nor hepatitis B immune globulin (HBIG) was 17.8% in 267 tested.
 The incidence of seroconversion after parenteral inoculation with HBV can be as high as 40%.
 All anesthetists should ensure that they are up to date with their immunization schedule. A blood test is
necessary to confirm immunity as the non-responder rate is 5–10% and boosters are required every 5 yr.
 OSHA mandates that employers make vaccination against HBV available at no cost to all employees.
 Unvaccinated anesthesiologists who suspect HBV exposure with an HBsAg-positive source should be passively
immunized with HBIG and begin a series of three injections of hepatitis B vaccine.
 The combination of HBIG and HBV vaccine prophylaxis is believed to be 85% to 90% effective, whereas
either treatment alone is 70% to 75% effective.

5. Hepatitis C
 Like HBV, HCV is transmitted principally by infected blood
 Transmission of HCV by contaminated needles occurs in less
than 4% of these injuries.
 No effective postexposure treatment is available for HCV/No vaccine exist.
 Recommendations for postexposure management are geared towards early recognition and intervention in
chronic disease.
 Chronic hepatitis develops in 85% of hepatitis C infections with 20% progressing to cirrhosis and 3% to
hepatocellular carcinoma
 Health care workers exposed to HCV should undergo baseline testing for anti-HCV and alanine
aminotransferase activity as soon as possible after the injury, with follow-up testing 3 and 6 months after
exposure

6. HIV
 Fortunately, HIV is a relatively fragile virus, and with proper
attention to cleanliness and care in performing invasive procedures,
the likelihood that the disease will develop in an anesthesiologist during the course of patient management is
very low.
 Epidemiological studies → Risk for HIV transmission → percutaneous exposure → 0.3%.
→mucocutaneous exposure → 0.03%
→Intact skin is exposed to HIV-infected blood →0%
 If occupational exposure does occur, the site of exposure should be washed immediately with soap and water.
 Routine methods of disinfection, sterilization, and housekeeping → HIV on instruments, surfaces, and laundry
can be destroyed.
 Post-exposure prophylaxis → maximally effective → Taken within an hour after an exposure,
but benefit may remain if commenced up to 2 weeks after exposure.

7. Tuberculosis
 The incidence of tuberculosis is increasing, both in isolation
and in association with other conditions such as HIV.
 Tuberculosis spreads by small (1–5 μm) droplets released when
an infected person speaks, coughs or sneezes.
 Droplets can travel up to 3 feet from the source and remain viable and airborne
for several days.
 Factors implicated in the transmission of the bacillus to an anesthetist include
bronchoscopy, laryngoscopy, tracheal intubation, suctioning of the airways and
mechanical ventilation.
 Healthy Individual→ Inhaled Contaminated droplets → Lifetime risk of
developing TB→10%

8.  OSHA standards to prevent airborne contamination include both environmental
controls and respiratory protection:
Environmental controls:
Engineering measures to manage exhaust ventilation and general ventilation.
Examples :- ↑ Air exchange rates,
High-efficiency particulate air (HEPA) filtration,
Ultraviolet germicidal irradiation (UVGI; irradiation of the air in the upper portion of room, Ducts)
Respiratory protection:
Masks that filter particles smaller than 1μm with a filter efficiency of 95% → N95 Masks
Face shields

9. Novel Infectious Agents
 Prion disease → CreutzfeldtJakob disease (CJD)(subacute spongiform encephalopathy)
 Coronavirus infections : Severe acute respiratory syndrome(SARS-CoV)epidemic2003
Middle East SARS {(MERS-CoV)(CFR>50%)},
H1N1 influenza outbreak of 2009,
Novel covid-19 outbreak

10. Lessons Learnt from Respiratory Virus Outbreaks
Source: CDC(Centers for Disease control and Prevention) WHO
SYSTEMS INDIVIDUALS
Anticipate future outbreaks Droplet and contact precautions
Develop staff and plans for dealing
with mass exposure
Eye protection
Adequate isolation equipment Staying home with fever or cough
Use of Simulation to test facility’s
readiness
Compliance with vaccination programs
Active surveillance
Data collection and reporting

11. Musculoskeletal morbidity
 Lacerations and glass splinters when opening drug ampoules are a common
occurrence.
 Where possible, plastic ampoules or plastic ‘ampoule snappers’ should be
used.
 The first metacarpophalangeal joint is the commonest joint to be affected by
osteoarthritis in any dexterous manual employment. Hand ventilation,
opening ampoules, drawing up and injecting drugs are all actions that
predispose to the development of this condition.

12. Latex Allergy
 The development of latex allergy is associated with repeated
latex exposure. In health care workers this often involves
the use of latex containing gloves.
 Responses range from irritant contact dermatitis, a delayed type IV reaction
mediated by T-cells to IgE-mediated anaphylactic shock.
 The use of latex free products, hand washing after contact with latex
containing products and educational programs aim to reduce the prevalence
of latex allergy.

13. Radiation
Ionizing Radiation : X-Rays
 Exposure is commonly reported in units of rem (roentgen equivalents man).
 A rem is a measure of the biologic damage from radiation adjusted to apply to all tissues.
 Maximum yearly occupational exposure is mandated to be no more than 5 rem
 Occupational exposure to radiation comes primarily from x-rays
 One chest radiograph results in approximately 25 mrem of exposure to the patient and procedures requiring
multiple films occasionally involve more than 1 rem.
 Best protection is physical separation, a distance of at least 3 feet from the patient is recommended.Six feet
of air will provide protection equivalent of 9 inches of concrete or 2.5mm of lead.
 Aprons containing the equivalent of 0.25 to 0.5mm of lead sheet are effective in blocking most scattered
radiation.
 Uncovered areas, such as the lens of the eye and thyroid still bear the risk of injury.
 Exposure is inversely related to the experience of the surgeon, and the amount of radiation received by the
anesthesiologist during orthopedic procedures.

14. Non Ionizing Radiation : LASERS
 Eye injuries are the greatest risk to personnel working near lasers.
 Either direct exposure or reflected radiation may cause eye damage.
 Injuries include burns to the cornea and retina, destruction of the macula or optic nerve, and cataract
formation.
 Protective eyewear is recommended for all personnel.
 Plume (vapor and cellular debris produced during laser surgery) may carry significant risks.
 Median size of particles in plume is 0.31μm in dia (range, 0.1 to 0.8μm).
 Most surgical masks do not trap such small particles.
 Exhaust smoke from tissues treated with a carbon dioxide laser causes pulmonary lesions.
 Intact HPV DNA has been detected in the vapor from both laser-treated plantar warts and genital warts.
 HIV proviral DNA has been found in laser smoke produced by vaporizing cultures of HIV-positive cell

15. Diathermy and laser smoke inhalation
 Inhalation of smoke and vapor generated by the use of surgical diathermy and lasers represents a potential
hazard to anesthetists.
 Surgical masks do not filter toxic gases nor trap particles <0.5 μm in diameter. The median diameter of
particles produced in smoke plumes is 0.31 μm.
 Pulmonary lesions have been found after inhalation of smoke from tissues treated with a carbon dioxide
laser.
 The smoke plume generated by diathermy has been found to contain carcinogens such as benzene. Other
chemicals (e.g. toluene, styrene, carbon disulphide) have been identified in diathermy smoke and can
cause corneal irritation, dermatitis, renal and hepatic toxicity and affect the central nervous system.
 Viable bacteria, human papillomavirus DNA and HIV proviral DNA have also been found in laser smoke under
experimental conditions.
 Exposure can be reduced effectively by suction devices, diathermy pencils with smoke evacuator.

16. Electromagnetic Fields
 The use of monitors and electrical equipment's continually exposes the
anesthetist to electromagnetic fields.
 Adverse health effects resulting from this exposure are not well defined but
there are reports that an increased risk of brain cancer, breast cancer and
leukemia occurs in populations exposed to electromagnetic fields.
 While the potential health hazards and safe upper limits of exposure remain
to be determined, anesthetists should aim to minimize their exposure.

17. Waste Anesthetic Gases
 Escape of anesthetic vapors into the operating room atmosphere is unavoidable.
 Waste anaesthetic gases include both nitrous oxide and halogenated anaesthetics such as halothane, enflurane,
isoflurane, desflurane and sevoflurane.
 Trace amounts of waste gases enter the operating room atmosphere each time an inhaled anesthetic is
delivered.
 Rule→ If the anesthetic can be smelled, its concentration is well above the maximum recommended level.
 1ml of volatile liquid
↓
200ml of vapor
↓
20x20x9 feet room
↓
2ppm concentration

18. Exposure Limits
NIH-National Institute of Health(Divn of occupational health and safety)
NIOSH-National Institute for occupational safety and health

19. Acute/Effect on
High
concentration
• Headache
•Irritability
•Fatigue
•Nausea
•Drowsiness
•Defect in cognitive and psychomotor
performance
Chronic/Effect
on low
concentration
•DNA damage
•Mutagenicity
•Liver and Kidney disease
•Oxidative stress
•Reproductive problems(spontaneous
abortion/developmental defects)
Health Effects

20. Facts
 Lara A. Oliveira et al published a critical review on 7 January 2021 aimed to systematically evaluate
spontaneous abortion in women occupationally exposed to occupational anesthetic.
Results:
a. Considering all 18 included studies, ten studies (55%) showed an association between occupational exposure to
inhalational anesthetics and spontaneous abortion, while eight studies (45%) did not show this association.
b. The exposed populations included different professionals, and the medical anesthesiologists/nurse anesthetists
and scrub nurses had the highest rates of abortion among the analyzed jobs.
c. Significantly increased spontaneous abortion rate in the group with the longer exposure period (Rowland et al.
1995)
d. The most frequently mentioned anesthetics were N2O and halothane in the studies.

21.  Mariana G Braz et al published an observational study in July 2018 on Detrimental effects detected in exfoliated buccal
cells from anesthesiology medical residents occupationally exposed to inhalation anesthetics.
Results:
a. The anesthesiology residents (high exposure group) showed statistically significant lower frequencies of basal cells and
higher frequencies of micronuclei, karyorrhexis, pyknosis, and differentiated cells than did the unexposed group(surgery
and medicine residents).
b. Karyolysis frequencies were significantly higher in anesthesiology residents than were those in the unexposed group or in
surgical residents (low exposure).
c. The findings suggest a genetic risk for young professionals exposed to WAGs at the beginning of their careers.
d. Thus, exposure to high WAGs concentrations leads to impairment of the buccal cell proliferative potential, genomic
instability and cell death, especially in anesthesiology residents, demonstrating an early impact on their health.

22. Where are workers most likely to be exposed to
waste anesthetic gases?
 operating facilities with no automatic ventilation or scavenging systems,
 recovery rooms where gases exhaled by recovering patients are not properly vented or scavenged.
 When leaks occur in the anesthetic breathing circuit (which may leak gas if the connectors, tubing, and valves
are not maintained and tightly connected)
 When anesthetic gas seeps over the lip of the patient’s mask or from endotracheal coupling (particularly if the
mask is poorly fitted—for example, during pediatric anesthesia)
 Via Uncuffed pediatric endotracheal tube.

23. How can employers reduce worker exposures to waste
anesthetic gases?
 Install a anesthesia gas scavenging system to remove waste anesthetic gases from the operating room.
 Place the exhaust in an area where waste gases will not be reintroduced into intake air for the facility.
 Install a ventilation system that circulates and replenishes the air in operating rooms (at least 15 air changes
per hour).
 Properly maintain anesthesia machines, breathing circuits, and waste-gas scavenging systems to minimize
leaks of anesthetic gases into the operating rooms.

24. How can operating-room personnel reduce their exposures to waste
anesthetic gases?
 Inspect the anesthetic delivery system before each use.
 Look for irregularities or breaks.
 Check the patient’s breathing circuit for negative pressure and positive pressure relief as part of the daily
machine checklist.
 Turn on the room ventilation system/AC.
 Make sure the scavenging equipment is properly connected.
 Start the gas flow after the laryngeal mask or endotracheal tube is installed.
 Fill vaporizers when no other personnel is their in OT and before or after OT.
 Use the lowest anesthetic gas flow rates possible: Avoid very high anesthetic gas flow rates to prevent leaks:
high flow rates generate more waste anesthetic gases than low flow rates.

25. Substance Abuse
 Potent psychoactive drugs are readily available and familiar to anesthesiologists
 A national survey published in 1992 reported a 2.1% annual and a 7.9% lifetime prevalence of substance abuse
among physicians.
 Three retrospective surveys suggest that the prevalence of drug abuse in anesthesiologists ranges from 1% to
2%.
 Although physicians are less likely to use cigarettes and illicit substances such as marijuana, cocaine, and
heroin, they are five times as likely to take sedatives and minor tranquilizers without medical supervision.
 Fentanyl is the most commonly abused narcotic, followed by sufentanil, meperidine, morphine, and oral
drugs.
 Sadly, loss of life may be the first indication that a physician is abusing drugs.

26.  Occupational stressors first surface in residency, during which long hours preclude much time for relaxation,
and certain patients may evoke negative emotions.
 The death of a patient under one’s care may cause a sense of professional inadequacy to surface for the first
time.
 Management of physicians who are chemically dependent includes :
identification
intervention
referral for treatment
and help with reentry.

27. Fatigue
 The impact of fatigue on patient safety has come to the forefront in recent decades.
 Well defined periods of vulnerability to sleep have been identified in humans, the major peak occurs
between 2 am and 7 am, and a smaller peak occurs in the midafternoon.
 These peaks appear to be enhanced by irregular work schedules and sleep disruption.
 Increased rates of anesthetic complications for cases started late in the day and during “off-hours” have
been reported.
 Being on duty every third or fourth night has a negative impact on the cognitive function and psychomotor
performance of residents.
 In a survey of 225 physicians, 48.8% blamed tiredness and 19.5% blamed the pressure of overwork to be a
significant cause of clinical mistakes and suboptimal patient care.
 A survey of retired members of ASA found that professional relationships (especially with surgeons), work
overload, threats of litigation, peer review, and increasing administrative responsibilities also contribute to
stress in the workplace.

28.  Anesthesiologist: The silent force behind the scene.
: Do not get adequate recognition as doctors both within the medical community as well
as outside from patients.
:No appreciation for their work and also underpaid as compared to surgeon’s fee even
when as responsible as the surgeon for the patients successful operation.

29. Life is all about balance,
Treat patients and treat yourself well
-Thank You