The Operating Room Environment Flashcards
How is oxygen stored?
Oxygen is stored as compressed gas in room temperature or refrigerated as liqiud.
Liquid oxygen must be stored well below its critical temperature of –119°C because gases can be lique ed by pressure only if stored below their critical temperature.
It is stored in H- and E-cylinders.
How is nitrous oxide stored?
Because the critical temperature of nitrous oxide (36.5°C) is above room temperature, it can be kept lique ed without an elaborate refrigeration system.
How do you determine the residual volume of nitrous oxide?
The only reliable way to determine residual volume of nitrous oxide is to WEIGH THE CYLINDER. For this reason, the tare weight (TW), or empty weight, of cylinders containing a liquified compressed gas (eg, nitrous oxide) is o en stamped on the shoulder of the cylinder.
What pressure gauge of NO should the cylinder not exceed?
745 psig (51 bar) at 20 C.
If liquid nitrous oxide is kept at a con- stant temperature (20°C), it will vaporize at the same rate at which it is consumed and will main- tain a constant pressure (745 psig) until the liquid is exhausted.
What is medical air?
Dehumidified but unsterile mix och oxygen and nitrogen. Critical temp is -140 C.
What is Nitrogen good for?
It is not administered to patients in OR. It can be used to drive equipment saws and drills.
Describe WAGD.
Waste anesthetic gas disposal system. Vacuum suction system. Excess suction may cause inadequate ventilation.
Describe the carbon dioxide gas.
Invisible. Odorless. Inflammable. Slightly acidic.
What is the optimal humidity level in the OR and why?
50-55%. Dry air facilitates airborne motility which can be a vector for infection. Dampness can affect the integrity of barrier devices such as sterile cloth drapes and panliners.
How should optimal ventilation of OR be?
High rate of air flow decreases contamination. Flow rates are achieved by blending 80% recirculating air and fresh air. This conserves energy associated w heating and air conditioning. But unsuitable for WAGD. Separate anesthetic gas scavenger system must always supplement OR ventilation system.
What are the radiation sensitive organs that must be protected?
Eyes Thyroid Gonads Blood and bone marrow Fetus
What is the most likely risk to surgical fires?
Open oxygen delivery.
What should be done if the airway catches fire?
Delivery of fresh gases to the airway should stop.
Effective means of stopping fresh gases to the patient can be accomplished by turning flowmeters, disconnecting the circuit from the machine, or disconnecting the circuit from the endotracheal tube. e endotracheal tube should be removed and either sterile water or saline should be poured into the airway to extinguish any burning members.
The sequence of stopping gas ow and removal of the endotracheal tube when re occurs in the airway is not as important as ensuring that both actions are performed quickly.
What should be used if the patient catches fire?
The flow of oxidizing gases should be stopped, the surgical drapes removed, and the re extinguished by water or smothering. e patient should be assessed for injury. If the fire is not immediately extinguished by first attempts, then a carbon dioxide (CO2) re extinguisher may be used.
