Flashcards in Chpt. 4 - Key Terms Deck (39):
A clear, aquarium-like box used to induce GA in small patients that are feral, vicious, or intractable or that cannot be handled without undue stress.
A cone-shaped device, ideally made of transparent material, used to administer oxygen and anesthetic gases to nonintubated patients via the nose and mouth. Also used to administer pure oxygen to dyspneic, hypoxic, or other critically ill patients requiring supplemental oxygen.
The anesthetic machine system that vaporizes liquid inhalant anesthetic and mixes it with the carrier gases. Vaporizers are classified as precision or nonprecision and vaporizer-out-of-circuit (VOC) or vaporizer-in-circuit (VIC).
The act of cutting off the supply of oxygen; suffocation.
Collapse of a portion or all of one or both lungs.
A non-rebreathing circuit with a fresh gas inlet entering at the patient end of the breathing tube at a 90-degree angle (like the base of the letter T) and without a reservoir bag at the opposite end of the breathing tube; Mapleson E circuit.
Bain coaxial circuit (Bain circuit)
A non-rebreathing circuit with a "tube within a tube" configuration that discharges fresh gas at the patient end of the breathing tube. Both the overflow valve and the reservoir bag are located away from the patient at the opposite end of the breathing tube; modified Mapleson D circuit.
The anesthetic machine system that conveys the carrier gases and inhalant anesthetic to the patient and removes exhaled carbon dioxide. Breathing circuits are classified as rebreathing circuits or non-rebreathing circuits.
Corrugated tubes that complete a rebreathing circuit by carrying the anesthetic gases to and from the patient. Each tube is connected to a uni-directional valve at one end and to the Y-piece at the other end.
Carbon dioxide absorber canister
The part of a rebreathing circuit that holds the carbon dioxide absorbent granules. These granules, primarily made of calcium hydroxide, remove expired CO2.
Closed rebreathing system
A breathing system in which the pop-off valve is kept nearly or completely closed and the flow of oxygen is relatively low, providing only the volume necessary to meet the patient's metabolic needs.
Common gas outlet
The point where the oxygen, inhalant anesthetic, and N2O, if used, exit the anesthetic machine on the way to the breathing circuit.
Compressed gas cylinders
A container that holds a large volume of highly pressurized gas. Oxygen, nitrous oxide, medical air, and carbon dioxide are stored in compressed gas cylinders.
Compressed gas supply
The anesthetic machine system that supplies carrier gases (oxygen and sometimes nitrous oxide).
Endotracheal tube (ET tube)
A flexible tube placed inside the trachea of an anesthetized patient and used to transfer anesthetic gases directly from the breathing circuit into the patient's trachea, bypassing the oral and nasal cavities, pharynx, and larynx.
A gas cylinder of graduated diameter that indicates carrier gas flow expressed in liters of gas per minute (L/min). reduces the pressure of the gas in the intermediate-pressure line from about 50 psi (about 345 kPa) to 15 psi (about 100 kPa).
Fresh gas inlet
The point at which the carrier and anesthetic gases enter the breathing circuit.
A non-rebreathing circuit with a fresh gas inlet at the patient end of the breathing tube and a reservoir bag at the opposite end. The fresh gas inlet enters the breathing tube at a 45- to 90-degree angle; Maple F circuit.
Co-axial modification of the Mapleson A system which facilitates expired gas scavenging.
A device consisting of a handle, a blade, and a light source; used to increase visibility of the larynx during placement of an endotracheal tube.
Line pressure gauge
A gauge that indicates the pressure in the intermediate-pressure gas line between the pressure-reducing valve and the flow meters.
A non-rebreathing circuit with an overflow valve at the patient end of the breathing tube. Both the fresh gas inlet and the reservoir bag are located away from the patient at the opposite end of the breathing tube; Mapleson A circuit.
Mapleson classification system
A system developed by W.W. Mapleson that is used to classify non-rebreathing circuits based on the position of the fresh gas inlet, the reservoir bag and the pressure-limiting valve.
An anesthetic machine fitted with a non-rebreathing circuit. In this system little or no exhaled gases are returned to the patient but are instead removed from the circuit by use of appropriately high flow rates of carrier gas and evacuated by a scavenger connected to a pressure-limiting valve or other exit port. Used most commonly for patients under 2.5 to 3kg in body weight.
Norman mask elbow
A non-rebreathing circuit with a fresh gas inlet at the patient end of the breathing tube and a reservoir bag at the opposite end.
The fresh gas inlet enters the breathing tube at a 45- to 90-degree angle, and the endotracheal tube connector is at right angles to the breathing tube; Mapleson F circuit.
Oxygen flush valve
A button or lever that rapidly delivers a large volume of pure oxygen (at a flow rate of 35 to 75 L/min) directly to the common gas outlet or breathing circuit of a rebreathing system, bypassing the anesthetic vaporizer and oxygen flow meters.
Also known as the pressure relief valve, exhaust valve, adjustable pressure limiting (APL) valve, or overflow valve; this valve is the point of exit of anesthetic gases from the breathing circuit.
A gauge that indicates the pressure of the gases within the breathing circuit, and by extension the pressure in the animal's airways and lungs. Expressed in centimeters of water (cm H2O), millimeters of mercury (mm Hg), or kilopascals (kPa).
A valve that reduces the pressure of a compressed gas to a constant safe operating pressure of 40 to 50 psi (275 to 345 kPa) regardless of pressure changes within the tank.
Rebreathing system (Circle system)
An anesthetic machine fitted with a rebreathing circuit. In this system exhaled gases minus carbon dioxide are recirculated and rebreathed by the patient, along with variable amounts of fresh oxygen and anesthetic. Appropriate for most patients over 2.5 to 3kg in body weight.
Also called a rebreathing bag. A rubber or plastic bag that serves as a flexible storage reservoir for expired and inspired gases. It also allows the anesthetist to observe respirations, confirm proper endotracheal tube placement, and ventilate for the patient.
Respiratory minute volume (RMV)
The amount of air that moves into and out of the lungs in a minute. The tidal volume multiplied by the respiratory rate.
The anesthetic machine system that disposes of excess and waste anesthetic gases outside of the building, so that inhalation by occupationally exposed individuals is minimized.
Semiclosed rebreathing system
A rebreathing system in which the pop-off valve is positioned partially open, and the flow of oxygen is relatively high, providing more volume than is necessary to meet the patient's metabolic needs.
Tank pressure gauge
A device attached to the yoke of an anesthetic machine or the pressure regulator of an H tank. Indicates the pressure of gas remaining in a compressed gas cylinder measured in pounds per square inch (psi) or kilopascals (kPa).
Tidal volume (Vt)
The volume of a normal breath (approximately 10 to 15 mL/kg body weight).
The inspiratory valve or expiratory valve of a rebreathing circuit. Controls the direction of gas flow through a rebreathing circuit as the patient breathes.
A vaporizer that is located in the breathing circuit. Nonprecision vaporizers are often positioned this way.