Anesthetic Gases in Healthcare

Healthcare Industry According to the U.S. Bureau of Labor Statistics, Healthcare was the largest industry in 2006 employing 14 million people of whom 13.6 million were wage/salary workers and 438,000 self-employed. In addition, 7 of the 10 fastest growing occupations were healthcare related, and were likely to generate 3 million new jobs in 10 years - more than any other U.S. Industry. Healthcare workers face many workplace hazards; in addition to physical injuries such as needle stick injuries, back injuries and workplace stressors, they also run the risk of exposure to anesthetic waste gases, sterilant gases, solvents and disinfectants. Due to the growth of this industry, injury reporting has increased over the past decade. Anesthetic Gases The primary function of anesthetic gases is to block the sensation of pain allowing the patient to undergo surgical or other procedures without distress. There are several different types of anesthetics – general, inhaled, injected, and regional. Of particular concern in the healthcare workplace is exposure to anesthetic vapors from causes involving dosing technique, equipment leaks or failures, and waste anesthetic gases (WAG). Due to the high risk of workplace exposure, monitoring programs are required by several regulatory agencies such as OSHA, NIOSH, the American Hospital Association (AHA) and the Joint Commission on Accreditation of Health Care Organizations. The most widely used anesthetic gases are halogenated ethers such as enflurane, halothane, isoflurane, and desflurane coupled with nitrous oxide. Did you know? Our radiello® Anesthetic Gas and Vapor Sampling (Sterile) Kit – RAD125 was developed to sample nitrous oxide, isoflurane, ethrane, halothane, and sevorane in surgical theaters? Components for one sampler are packed separately in one sealed and sterile bag; each sampler includes: 1 permeative body, 1 support plate, 1 vertical adapter, and 1 adsorbing cartridge. Commonly Encountered Waste Gases, Chemicals, Vapors in Healthcare Nitrous Oxide Halogenated Ethers – Forane (isoflurane), Ethrane (Enflurane), Desflurane, Halothane, Sevorane Sterilant Gases – Ethylene Oxide Solvents, Disinfectants and Antiseptics – Aldehydes (Glutaraldehyde, Formaldehyde, Acetaldehyde); Phenols Methyl Methacrylate (MMA)

Nitrous Oxide is a commonly used anesthetic/analgesic in dentistry and surgical operations and is often referred to as “laughing gas”. Occupational exposure from inhalation can result in neurotoxic effects, also decrease in mental performance and audiovisual dexterity. It is often used with sevoflurane or desflurane in order to strengthen the anesthetic effect.

Forane (Isoflurane)
Is used primarily in veterinary procedures and is often combined with other anesthetics such as nitrous oxide. It is widely used and has a stabilizing effect on the cardiovascular system. It’s less soluble in blood than halothane therefore results in more rapid recovery. Common signs of exposure are dizziness and headache and unconsciousness (in extreme cases). Pregnant women and operating personnel should minimize exposure.

Ethrane (Enflurane)
Is a vasodilator acting directly on smooth muscles. It is a non-flammable halogenated ether used as a general inhaled anesthetic primarily in veterinary procedures. It is a structural isomer of isoflurane. Extremely lipid (fat) soluble; may have prolonged action in obese individuals.

Desflurane
Is a highly fluorinated methyl ethyl ether used for maintenance of general anesthesia. It has lower blood and body tissue solubility therefore its uptake and elimination from the body is faster. It undergoes minimal metabolism and should have low potential for toxic effects.

Halothane (bronchiodialator)
Used since the 1960s, probably still the most widely used in the world though isoflurane is generally used in UK and USA. Halothane is in essence halogenated ethane (enflurane and isoflurane are halogenated methyl ethyl ethers). Chronic exposure said to lead to nervous system toxicity and behavioral changes. When used as a clinical anesthetic, halothane induces amnesia, analgesia, anesthesia, and respiratory depression [Hathaway et al. 1991]. Anesthetic doses range from 5000 to 30,000 ppm [ACGIH 1991]. During anesthesia, cardiac output may be reduced and arrhythmias may occur [Hathaway et al. 1991]. A syndrome called "halothane hepatitis" occurs in 1 in 10,000 halothane-induced anesthesia patients; this syndrome involves fever, anorexia, nausea, and vomiting and may progress to hepatic failure and death [Hathaway et al. 1991].
Is extremely sensitive to light and decomposes to toxic gases of bromine, chlorine and fluorine if not properly stabilized. It is incompatible with acids, light, heat and flames.

Sevorane (Sevoflurane)
Sevoflurane is the preferred agent for mask induction due to its lesser irritation to mucous membranes, along with desflurane, it is replacing halothane and forane. Like the other halogenated ethers, it is administered in a mixture of nitrous oxide and oxygen.
The U.S. Environmental Protection Agency (EPA) has classified sevoflurane as a greenhouse gas.

Ethylene Oxide (EtO)
Ethylene oxide is commonly used a sterilant for medical equipment and supplies. It is both flammable and highly reactive. Acute exposures to the gas may result in respiratory irritation and lung injury, headache, nausea, vomiting, diarrhea, shortness of breath, and cyanosis. Chronic exposure has been associated with the occurrence of cancer, reproductive effects, mutagenic changes, neurotoxicity, and sensitization. Acute overexposure to ethylene oxide causes conjunctival skin, and respiratory tract irritation, including rhinitis, cough, and shortness of breathe.

Aldehydes

Glutaraldehyde
Glutaraldehyde is a toxic chemical that is used as a cold sterilant to disinfect and clean heat-sensitive medical, surgical and dental equipment. It is used in a limited number of applications, rather than as a general disinfectant. Specific applications include use as a disinfecting agent for respiratory therapy equipment, bronchoscopes, physical therapy whirlpool tubs, surgical instruments, anesthesia equipment parts, X-ray tabletops, dialyzers, and dialysis treatment equipment.

Short-term exposure has been known to burn irritate the mucous membranes and the skin. Inhaling it can irritate the nose, throat and respiratory system resulting in coughing and wheezing. It may also cause nausea, drowsiness, dizziness and nosebleeds. Long-term effects result from Glutaraldehyde as a desensitizer. Those who are desensitized have strong reactions even with little exposure to the compound. Common responses are asthma attacks and trouble breathing, but also skin allergies and eczema, itching and rashes. It is one of the leading causes of workplace asthma.

Formaldehyde
Formaldehyde is a common indoor air pollutant that is colorless with a strong and unique odor. It is present in medical preservatives, as a component of surgical smoke, adhesives, particleboard, paints and coatings, paper, foam, etc. Workers can inhale formaldehyde in the gas form and adsorb it in the liquid form through the skin. Exposure may result in irritated or burning eyes, stuffy nose and skin rashes. It is also known to cause headaches and flu-like symptoms. Chronic exposure may also result in bronchitis. It can also trigger other ailments like asthma, and behave as an allergen.

It is one of the only VOC’s regulated by the EPA. However, OSHA regulates it as a known carcinogen. Formaldehyde is also a concern in other industries such as healthcare-human and animal, teachers and students in a laboratory environment, construction workers, pulp and paper, automotive, maritime, and so on. It is also a common contaminant investigated in Vapor Intrusion, Sick Building, and Building related illness cases.

Acetaldehyde
Acetaldehyde is a volatile, flammable and colorless liquid with a pungent, fruity odor commonly used in disinfectants. It is widely used as a chemical intermediate, principally for the production of acetic acid, pyridine and pyridine bases, peracetic acid, pentaerythritol, butylene glycol, and chloral. It is used in the production of esters, particularly ethyl acetate and isobutyl acetate. It is also used to manufacture dyes and aniline rubber, as a flavorant, component of paints, adhesives, coatings, etc. It is dangerous when exposed to heat or flame; it can react vigorously with oxidizing material, acid anhydrides, alcohols, ketones, phenols, halogens, isocyanates, and strong alkalides and amines. It is also incompatible with acids, bases, alcohol, ammonia, amines, phenols, ketones, and hydrogen cyanide. It will polymerize readily in the presence of trace metals (iron). Acetaldehyde can form unstable or explosive peroxides with exposure to air. It may polymerize under influence of air and heat, acids, or bases with potential of fire or explosion. It is polymerized violently by concentrated sulfuric acid. Rubber products decompose on contact with acetaldehyde, but it is not corrosive to most metals.

Workers in a wide range of industries from Healthcare to Paints and Coatings can be exposed by inhaling the fumes. When ingested or inhaled, acetaldehyde can irritate the eye, nose, and throat; cause conjunctivitis, coughing, central nervous system depression, eye and skin burns, dermatitis, and delayed pulmonary edema.

Acetaldehyde is a by-product of yeast production and is a naturally occurring compound in wine, bread, soy sauce and other yeast fermented products. It is approved for use in phenolic resins in molded containers for contact with nonacidic foods. Acetaldehyde is exempted from a residue tolerance when it is used as a fumigant for storage of apples and strawberries.

Phenolic Compounds (Phenols)

Phenol is commonly used as an antiseptic and analgesic in the Healthcare Industry. It also has other uses such as the primary chemical in embalming fluid for its preservation characteristics. It is more widely used for this purpose in medical embalming versus for public where formaldehyde is most often used. It has other uses such as in the manufacture of drugs, herbicides, synthetic resins, and cosmetics.

Common symptoms of exposure: Eye, nose, throat irritation; anorexia, nausea, vomiting, weight loss, lassitude (weakness, exhaustion), headache, dizziness, muscle ache, pain; cardiac arrhythmia; labored breathing, shortness of breath, pulmonary edema, cyanosis; liver, kidney damage; skin burns, dermatitis; ochronosis; tremor, convulsions, twitching; metabolic acidosis.
Skin Absorption: Numbness, collapse, coma.
Ingestion: acute abdominal pain, sore throat, diarrhea; smoky, greenish-dark urine; shock or collapse.

Methyl Methacrylate (MMA)
Methyl Methacrylate is used in the healthcare and dentistry industries as bone cement. It is a monomer of acrylic resin that is both moldable and pliable. When exposed to MMA in the dental office, dentists and other dental staff may experience hypersensitivity, asthmatic reactions, local neurological symptoms, irritant and local dermatological reactions. It is irritating to the skin, eyes, and mucous membranes and may also result in allergic reaction.

In addition to its use in the healthcare field, MMA is widely used in the manufacture of resin and plastics and is impregnated in concrete to make it water repellant.