Aseptic Technique, Sterilization, and Hospital Hygiene

Comprehensive vocabulary flashcards covering medical asepsis, disinfection classifications, chemical agents, physical and chemical sterilization protocols, biological indicators, and surgical hand preparation.

Antiseptics

Medicinal and veterinary products applied topically to living human or animal tissues, broken skin, or patient skin prior to procedures to destroy microorganisms or inhibit their growth, aiming for relative sterility rather than $100\%$ decontamination.

Disinfectants

Chemical formulations used to destroy microorganisms on inanimate (abiotic) surfaces.

Critical Items (Spaulding Classification)

High-risk medical devices that enter sterile tissues or the vascular system (e.g., surgical instruments, needles, vascular catheters) and must be absolutely sterile (single-use or sterilized).

Semicritical Items (Spaulding Classification)

Medium-risk medical devices that come into contact with intact mucous membranes or non-intact skin (e.g., endoscopes, intubation sets, vaginal specula), requiring sterilization or high-level disinfection before use.

Non-critical Items (Spaulding Classification)

Low-risk objects that contact only intact skin (e.g., blood pressure cuffs, bed linen, patient room furnishings), requiring cleaning and periodic disinfection to prevent secondary pathogen transmission.

High-Level Disinfection (HLD)

A disinfection process whose efficacy is comparable to sterilization, eliminating bacteria, fungi, viruses, and some bacterial spores; primarily applied to semicritical medical equipment.

Low-Level Disinfection

A process that kills most vegetative bacteria and fungi but does not eliminate bacterial spores, mycobacteria, or non-enveloped viruses, utilized for non-critical surfaces and equipment.

Thermal Disinfection

A decontamination method utilizing hot water at $93\text{--}95^\circ\text{C}$ or water steam under an overpressure of $0.5\,\text{atm}$ at $105\text{--}110^\circ\text{C}$, commonly applied to hospital linens, dishware, and sanitary furnishings.

Thermo-chemical Disinfection

A procedure combining heat at $60\text{--}65^\circ\text{C}$ with chemical disinfectant formulations, applied to decontaminate heat-sensitive equipment.

Sterility Assurance Level (SAL)

The metric of biocidal process efficacy defining the probability of a non-sterile unit; a SAL guarantee of $10^{-6}$ represents the required standard for sterilization.

Leak Test (Vacuum Leak Rate Test)

A physical autoclave performance test that measures the pressure stability in the sterilizer chamber at a reduced pressure of approximately $100\,\text{mbar}$.

Bowie-Dick Test

A routine test used in large steam sterilizers with porous load cycles to verify the effective removal of air from the sterilization chamber.

Povidone-Iodine (PVP-I)

An antiseptic active against all vegetative bacteria, bacterial spores, fungi, enveloped viruses, and protozoa; however, its aqueous solution is ineffective against adenoviruses and hepatitis B virus (HBV).

Octenidine Dihydrochloride (OCT)

An antiseptic effective against Gram-positive and Gram-negative bacteria, fungi (predominantly Candida albicans and certain dermatophytes), HBV, HSV, and protozoa (Trichomonas sp. within $1\,\text{min}$), but lacking activity against bacterial spores and enveloped viruses generally.

Chlorhexidine (CHX)

An antiseptic with high activity against Gram-positive bacteria, fungi, HIV (after $15\text{--}30\,\text{s}$), HSV-1 and HSV-2 (up to $2\,\text{min}$), and HBV ($>2\,\text{min}$), but ineffective against bacterial spores at room conditions and ineffective against non-enveloped viruses.

Pressurized Saturated Steam Sterilization

A high-temperature moist heat method operating either at $1\,\text{atm}$, $121^\circ\text{C}$ for $15\text{--}20\,\text{min}$ or at $2\,\text{atm}$, $134^\circ\text{C}$ for $3\text{--}5\,\text{min}$; leaves no toxic residues and requires packs to be completely dry post-cycle.

Tyndallization

A fractional sterilization method using flowing steam at approximately $100^\circ\text{C}$ for $20\text{--}30\,\text{min}$ performed three times at $24\,\text{h}$ intervals in Koch or Arnold apparatuses, used for liquids and culture media.

Dry Heat Sterilization (Hot Air)

A method using dry air at $160^\circ\text{C}$ for $120\,\text{min}$ or $180^\circ\text{C}$ for $30\,\text{min}$ for moisture-sensitive items like powders and oils; limited by poor heat penetration of dry air.

Ethylene Oxide (EO) Sterilization

A low-temperature gaseous method ($450\text{--}1200\,\text{mg/l}$, $40\text{--}80\%$ humidity, $37\text{--}65^\circ\text{C}$, $190\,\text{min}$) for heat-sensitive critical supplies; requires degassing at $18\text{--}22^\circ\text{C}$ for several days or at $50^\circ\text{C}$ for up to $12\,\text{h}$ due to human toxicity.

Low-Temperature Formaldehyde Sterilization

A chemical method ($2\text{--}5\%$ concentration, $48\text{--}70^\circ\text{C}$, $>70\%$ humidity, $120\text{--}240\,\text{min}$) for instruments up to $1.5\,\text{m}$ length and diameter $<2\,\text{mm}$; toxic at levels $>5\,\text{ppm}$ and detectable by odor at $0.5\text{--}1\,\text{ppm}$.

Peracetic Acid Sterilization

A rapid chemical sterilization method employing $0.2\%$ peracetic acid at $50\text{--}55^\circ\text{C}$ for $30\,\text{min}$ requiring full immersion of thermolabile instruments in dedicated cassettes for immediate point-of-use application.

Hydrogen Peroxide Gas Plasma Sterilization

A low-temperature method using $50\text{--}55\%$ hydrogen peroxide at $38\text{--}50^\circ\text{C}$ for $30\text{--}75\,\text{min}$; non-toxic with end-products of water and oxygen, but contraindicated for cellulose, linen, powders, liquids, or long dead-ended narrow lumens.

Radiation Sterilization

An industrial sterilization technique using radioactive isotopes Cobalt-60 ($^{60}\text{Co}$) or Cesium-137 ($^{137}\text{Cs}$); leaves no toxic residues but can induce polyethylene oxidation, causing delamination and cracking.

Biological Indicators (Sterilization Monitoring)

Preparations containing highly resistant bacterial endospores used to confirm cycle lethality, specifically Bacillus atrophaeus at $10^6$ spores and Geobacillus stearothermophilus at $10^5$ spores.

Sterile Storage Parameters

Required storage conditions for sterilized materials: ambient temperature of $15\text{--}25^\circ\text{C}$, relative humidity of $40\text{--}60\%$, and placed loosely on shelves at least $30\,\text{cm}$ away from the floor, walls, and ceiling.

Decontamination of Blood and Sputum Spills

A two-stage procedure: covering the spill with absorbent paper towels soaked in disinfectant solution or applying disinfectant granules, discarding into infectious waste bags after contact time, followed by full secondary re-disinfection.

Transient Skin Microbiota (Mikrobiota przejściowa)

Microorganisms that colonize the superficial layers of the skin temporarily, possess high pathogenic potential, and are easily removed during hand hygiene procedures.

Resident Skin Microbiota (Mikrobiota stała)

Microorganisms inhabiting deeper structures such as sweat glands, sebaceous glands, and hair follicles; they exhibit high pathogenicity, are difficult to eradicate, and require reduction via surgical scrub protocols.

Surgical Hand Washing (Chirurgiczne mycie rąk)

A specialized preoperative scrub procedure aimed at removing all physical contamination, completely eliminating transient flora, and significantly reducing resident microbiota on the hands and forearms.