CH. 29 PREVENTING AND SOLVING ANESTHESIA
MACHINE PROBLEMS
_____ and _____ have collaborated to develop recommendations for checking out an
anesthesia machine prior to administering an anesthetic - Answer -The American
Society of Anesthesiologists (ASA) and the Food and Drug Administration (FDA)
An anesthesia machine's main function will always be to provide - Answer -a controlled
supply of oxygen and other anesthetic gases to the patient during surgery
The high-pressure circuit starts where - Answer -the gas enters the machine and ends
at the flow control valves
a full tank of N2O has ___ psi - Answer -745 psi
O2 tanks have ___ psi when full - Answer -2,200
Fail-safe valve it serves to - Answer -decrease the supply of nitrous oxide if the oxygen
pressure drops
The low-pressure system of the anesthesia machine begins - Answer -downstream of
the flow valves
If _______ in the anesthesia machine is detected, the following items should be
examined:
Check for low pressure leak.
Check for a circuit disconnect starting with the patient and working back to the machine.
Inspect bellows.
Inspect CO2 canister.
Check lids/coupling of vaporizers.
Inspect the flow sensor.
Check oxygen pressure from pipeline/cylinder.
Check for incompetent ventilator relief valve. - Answer -low pressure
The most common cause for a low-pressure alarm is a - Answer -leak in the low-
pressure circuit
The most common cause of a leak is a - Answer -disconnection or partial disconnection
in the patient circuit
High negative pressure in the scavenging system can also cause ____ pressure in the
breathing circuit - Answer -high
, An incompetent ventilator relief valve can lead to _____ because gas is delivered to the
scavenging system instead of to the patient when the bellows collapse - Answer -
hypoventilation
A common cause for a hypoxic gas mixture alarm is _______ of the oxygen sensor at
the time of machine checkout - Answer -improper calibration
These steps are to fix machine if:
Turn on 100% oxygen and check for proper reading from the oxygen sensor.
Recalibrate the O2 sensor.
Replace O2 electrode if it does not appropriately recalibrate.
Check for main pipeline crossover. - Answer -Hypoxic Gas Mixture
These steps are to fix machine if:
Check for a leak.
Check for a stuck bobbin - Answer -Flowmeter Problems
These steps are to fix machine if:
Check for low-pressure leak.
Check for a circuit disconnect starting with the patient and working back to the machine.
Inspect bellows.
Inspect CO2 canister.
Check lids/coupling of vaporizers.
Inspect the flow sensor.
Inspect gas analyzer sampling rate.
Check oxygen pressure from pipeline/cylinder.
Check for an incompetent ventilator relief valve.
Rule out ventilator problems by switching to manual ventilation mode.
Rule out anesthesia machine problems by switching to an Ambu bag and/or an
alternative form of anesthetic delivery (e.g., intravenous anesthesia). Perform a leak
test. - Answer -Ventilator will not fill: The most common cause is a leak in the system.
Perform the same steps as above to investigate a low-pressure alarm. In addition,
check for an incompetent ventilator relief valve.
These steps are to fix machine if:
Look for inspiratory reverse flow/negative inspiratory flow alarm.
Check for high airway pressures.
Check for an incompetent expiratory valve. - Answer -Ventilator will not deliver a breath
These steps are to fix machine if:
Check the breathing circuit from the machine to the patient for kinking or any type of
obstruction
Check the ETT for obstruction (kinking, secretions, mainstem intubation, etc.)
Consider patient pathophysiology (bronchospasm, tension pneumothorax, stone chest,
etc.)
Check pop-off valve
MACHINE PROBLEMS
_____ and _____ have collaborated to develop recommendations for checking out an
anesthesia machine prior to administering an anesthetic - Answer -The American
Society of Anesthesiologists (ASA) and the Food and Drug Administration (FDA)
An anesthesia machine's main function will always be to provide - Answer -a controlled
supply of oxygen and other anesthetic gases to the patient during surgery
The high-pressure circuit starts where - Answer -the gas enters the machine and ends
at the flow control valves
a full tank of N2O has ___ psi - Answer -745 psi
O2 tanks have ___ psi when full - Answer -2,200
Fail-safe valve it serves to - Answer -decrease the supply of nitrous oxide if the oxygen
pressure drops
The low-pressure system of the anesthesia machine begins - Answer -downstream of
the flow valves
If _______ in the anesthesia machine is detected, the following items should be
examined:
Check for low pressure leak.
Check for a circuit disconnect starting with the patient and working back to the machine.
Inspect bellows.
Inspect CO2 canister.
Check lids/coupling of vaporizers.
Inspect the flow sensor.
Check oxygen pressure from pipeline/cylinder.
Check for incompetent ventilator relief valve. - Answer -low pressure
The most common cause for a low-pressure alarm is a - Answer -leak in the low-
pressure circuit
The most common cause of a leak is a - Answer -disconnection or partial disconnection
in the patient circuit
High negative pressure in the scavenging system can also cause ____ pressure in the
breathing circuit - Answer -high
, An incompetent ventilator relief valve can lead to _____ because gas is delivered to the
scavenging system instead of to the patient when the bellows collapse - Answer -
hypoventilation
A common cause for a hypoxic gas mixture alarm is _______ of the oxygen sensor at
the time of machine checkout - Answer -improper calibration
These steps are to fix machine if:
Turn on 100% oxygen and check for proper reading from the oxygen sensor.
Recalibrate the O2 sensor.
Replace O2 electrode if it does not appropriately recalibrate.
Check for main pipeline crossover. - Answer -Hypoxic Gas Mixture
These steps are to fix machine if:
Check for a leak.
Check for a stuck bobbin - Answer -Flowmeter Problems
These steps are to fix machine if:
Check for low-pressure leak.
Check for a circuit disconnect starting with the patient and working back to the machine.
Inspect bellows.
Inspect CO2 canister.
Check lids/coupling of vaporizers.
Inspect the flow sensor.
Inspect gas analyzer sampling rate.
Check oxygen pressure from pipeline/cylinder.
Check for an incompetent ventilator relief valve.
Rule out ventilator problems by switching to manual ventilation mode.
Rule out anesthesia machine problems by switching to an Ambu bag and/or an
alternative form of anesthetic delivery (e.g., intravenous anesthesia). Perform a leak
test. - Answer -Ventilator will not fill: The most common cause is a leak in the system.
Perform the same steps as above to investigate a low-pressure alarm. In addition,
check for an incompetent ventilator relief valve.
These steps are to fix machine if:
Look for inspiratory reverse flow/negative inspiratory flow alarm.
Check for high airway pressures.
Check for an incompetent expiratory valve. - Answer -Ventilator will not deliver a breath
These steps are to fix machine if:
Check the breathing circuit from the machine to the patient for kinking or any type of
obstruction
Check the ETT for obstruction (kinking, secretions, mainstem intubation, etc.)
Consider patient pathophysiology (bronchospasm, tension pneumothorax, stone chest,
etc.)
Check pop-off valve
