ANESTHETIC MACHINES AND RELATED EQUIPMENT

ANESTHETIC MACHINES AND RELATED EQUIPMENT Dr. Glenn Pettifer Room 1831 email: gpettifer@mail.vetmed.lsu.edu REFERENCES • Lumb & Jones Chapter 14, pages 366-408 • Handouts OBJECTIVES • Become familiar with the basic design of an anesthetic machine • Become familiar with the design and functioning of anesthetic vaporizers. • Become familiar with the design and functioning of the more commonly used breathing circuits CONSIDERATIONS • ANESTHETIC CONCENTRATION CONTROL • BUILD UP OF CARBON DIOXIDE • CONSUMPTION OF OXYGEN • ATMOSPHERIC POLLUTION • SIZE • AIRWAY CONTROL VAPORIZER Function: • to provide a means for anesthetic vapor to be combined with the carrier gas in a controlled manner. VAPORIZER CLASSIFICATION • OUTPUT REGULATION – VARIABLE BYPASS VS. MEASURED FLOW VARIABLE BYPASS Patient Flowmeter Patient Flowmeter Patient Flowmeter MEASURED FLOW PRECISION VS. NONPRECISION PRECISION VAPORIZER PRECISION VAPORIZER • • • • • FLOW COMPENSATED TEMPERATURE COMPENSATED HIGH RESISTANCE KNOWN CONCENTRATION AGENT SPECIFIC NON-PRECISION VAPORIZER NON-PRECISION • NO TEMPERATURE OR FLOW COMPENSATION • NOT AGENT SPECIFIC • PRECISE CONCENTRATION NOT KNOWN CARRIER GASES • Oxygen • Nitrous Oxide • supplied in cylinders as a gas (oxygen) or liquid (nitrous oxide) under pressure CYLINDER IDENTIFICATION • Color – Oxygen = Green (US) or White (everywhere else) – Nitrous oxide = Blue CYLINDER IDENTIFICATION • Labels CYLINDER IDENTIFCATION • PIN Index Safety System CYLINDER SIZES • E Tanks • H tanks • Bulk Tanks PIPELINES PIPELINE CONNECTION PRESSURE GAUGE CALCULATING VOLUMES* • H tanks = 7000 litres at 2000 psi • E tanks = 700 litres at 2000 psi • QUESTION? – HOW MANY LITRES IN AN E TANK READING 750 PSI? A dog is connected to an anesthetic machine with the oxygen flow rate set at 2 litres per minute. Prior to moving the dog to the radiology room (no overhead oxygen) you notice that the pressure gauge reads 250 psi. How many minutes can this dog be maintained at this flow rate? PRESSURE REGULATOR FLOWMETERS FRESH GAS PORT OXYGEN FLUSH VALVE • BYPASSES VAPORIZER • DELIVERS LARGE VOLUMES OF OXYGEN TO BREATHING CIRCUIT • IS UNDER HIGH(ER) PRESSURE CAUTION!!! OXYGEN FLUSH VALVE OXYGEN FLUSH VALVE CONSIDERATIONS • • • • • • ANESTHETIC CONCENTRATION CONTROL CONSUMPTION OF OXYGEN BUILD UP OF CARBON DIOXIDE ATMOSPHERIC POLLUTION SIZE AIRWAY CONTROL