Week 4- Anesthesia Machine Overview

Question 1

Major Components of the Anesthesia Workstation

Answer 1

◦ gas supply devices
◦ anesthesia machine
◦ vaporizers
◦ ventilator
◦ breathing system
◦ scavenging system
◦ respiratory and hemodynamic monitors
◦ suction

Question 2

Benefits of Anesthesia Workstation:

Answer 2

• Monitors, Control functions, alarms all integrated into 1 screen
• Reduces connections/misconnections that can lead to poor pt outcomes

Question 3

Disadvantages of Anesthesia Workstation

Answer 3

-Extensive knowledge required of how it works/ trouble shooting
-Many different models (may need to study manuals prior)
-Potential disruption of gas delivery & mechanical ventilation
-

Question 4

Standards of Anesthesia workstations are

overseen by?

Answer 4

◦ American Society for Testing and Materials
ASTM (since 2000)
◦ American National Standards Institute ANSI
(prior to 2000)

Question 5

Name some basic components of the Anesthesia Machine

Answer 5

• Oxygen Hanger Yoke with check valves
• N20 Hanger Yoke with check valves
• Cylinder pressure gauges (both sides)
• Oxygen Flush Valve
• 02 & N20 Flowmeters
• Common Manifold
• Calibrated Vaporizers
• Machine Outlet (ALSO “Common Gas Outlet”)
• Interface Valve for Scavenging System
• Scavenging Reservoir bag
• Patient Circuit

Question 6

Gas Cylinders are a part of what system

Answer 6

High pressure system

Question 7

Gas from O2 and Air Cylinders enter the machine at what pressure…

Answer 7

2000-2200 psi

Question 8

Gas from N20 Cylinders enter the machine at what pressure…

Answer 8

Approx 750 psi

Question 9

Cylinder Pressure Regulator

Answer 9

• Near Hanger Yokes/ past first check valve

- DOWN REGULATES Pressure to approx 45psi (on either side)

Question 10

Second Stage Regulator

Answer 10

• Not on all Machines**
• DOWN REGULATES pressure of..
• ->O2 to 14psi
• ->N20 to 26psi

Question 11

Oxygen Flush Valve

Answer 11

Directly fills breathing system with 100% FiO2 at 35-75L/min (HIGH FLOW VOLUME)
this is Direct Route= Beware of High pressure/ Barotrauma

Question 12

Pressure Sensor Shutoff Valve

Answer 12

• Consists of Pressure sensor and connects to Alarm system
• Primary Job= Senses if there is a drop in O2 pressure coming from either Wall or cylinder
• If P < 25, 28, or 30 (model depending)= Activates alarm system, and turns down all other gases (N20) besides O2 that might dilute O2 conc.
• Does not prevent toxic gas mixture…ONLY DETECTS PRESSURE**

Question 13

Oxygen Supply Failure Alarm System

Answer 13

• Alarms if O2 pressure <25, 28, or 30 psi (model depending)
• Detected by Pressure sensor shutoff valve
• Ritchie Whistle
• Does not prevent toxic gas mixture…ONLY DETECTS PRESSURE**

Question 14

Power Outlet to Ventilator

Answer 14

-uses 100% o2 to power/ pushdown/ compress the bellow

Question 15

Wall Supply Oxygen/N20 Pipeline Inlet(s)

Answer 15

• Hospital pipeline source (also at high pressures)

- ALL Wall Supply pipelines DOWN REGULATE to 50 psi

Question 16

Why is DOWN REGULATED Wall supply pressure higher than that of the Cylinders?

Answer 16

• Wall Supply Down Regulated to 50psi vs Cylinders at 45psi
• Allows for preferential supply to come from the wall supply pipeline thats plentiful
• Prevents bleeding the cylinders

Question 17

Flowmeters

Answer 17

Gases join and mix with other gases in the mixing chambers

LPS after knobs*

Question 18

Common Gas outlet (Machine Outlet)

Answer 18

Leaves to go directly to breathing system

Question 19

APL valve

Answer 19

Adjustable Pressure Limiting Valve

Question 20

Gauges

Answer 20

Provide readings and measurements

Question 21

Check Valves

Answer 21

• Unidirectional valve
• Prevents back flow of gases backwards in the system.
• Ex Outlet check valve

Question 22

Check Valves

Answer 22

• Unidirectional valve
• Prevents back flow of gases backwards in the system.
• Open and close
• Ex Outlet check valve

Question 23

Regulators

Answer 23

Reduce Pressure

Question 24

Five Pathways of Oxygen

Answer 24

1. Flow to the fresh gas flowmeters
2. Powers the Oxygen flush valve
3. Activates the fail-safe valve/mechanism
4. Activates the Oxygen supply low-pressure
   alarm
5. Compresses the bellows of the ventilator