hello..i just want to ask a topic that has been quiet hard to understand for me..i have been learning about anesthesia machine from few books ( "understanding anesthesia equipment" and "anesthesia equipment: principles and applications") ..and i found it hard to understand about several things..so,i decided to ask it here:
it is about the compressed volume :
well, i do understand that it is the volume lost inside the circuit because of the compliance n expansion of the tubing when pressurized..but i am confuse about how it is related to the aparatus dead space..so ,here are my questions:
1. apparatus (mechanical) dead space is commonly known as where the circuit has bidirectional flow( and contains fresh gas or "used" alveolar gas or mixed gas)..,right?
so, if the breathing tube accomodates fresh gas, expired gases or mixed (like in mapleson) ,can i call compressed volume as an apparatus dead space too?many literatures are not clear about this..
2. in the circle system,does the fresh gas can never meet with the exhaled gas if the unidirectional valves are intact and everything were properly positioned?
if the answer is "they can not meet" ..then i have another question:
3.Don't the breathing circuit in the circle system has a compressed volume too? if it do, can we relate it as a dead space too?
i have been thinking about it and become confused .. in many literature, it has been said that "because of the unidirectional valves, the apparatus dead space in circle system are only between the Ypiece and the patient"..i believe this is very true if the fresh gas indeed can never meet the exhaled gas in the tubing and of course, we can't call the "compressed volume" in the circle system as the apparatus dead space..am i right?
BUT one of the book clearly said "in the past, the unidirectional valves have been incorporated inside the y piece to decrease the apparatus dead space effect of compliance volume" (quote from "Anesthesia Equipment : Principles and Practice")...so, the compressed volume in circle system does contribute to apparatus dead space..?
..i don't get it...this statement really contradicts the previous statement..which one is true?
i am sorry for the long post..i am very confuse about this...please help..i really want to understand this concept...
if i am misunderstanding something, please just say it to me..it may help me too 🙂
thank you,
best regards,Ketap
it is about the compressed volume :
well, i do understand that it is the volume lost inside the circuit because of the compliance n expansion of the tubing when pressurized..but i am confuse about how it is related to the aparatus dead space..so ,here are my questions:
1. apparatus (mechanical) dead space is commonly known as where the circuit has bidirectional flow( and contains fresh gas or "used" alveolar gas or mixed gas)..,right?
so, if the breathing tube accomodates fresh gas, expired gases or mixed (like in mapleson) ,can i call compressed volume as an apparatus dead space too?many literatures are not clear about this..
2. in the circle system,does the fresh gas can never meet with the exhaled gas if the unidirectional valves are intact and everything were properly positioned?
if the answer is "they can not meet" ..then i have another question:
3.Don't the breathing circuit in the circle system has a compressed volume too? if it do, can we relate it as a dead space too?
i have been thinking about it and become confused .. in many literature, it has been said that "because of the unidirectional valves, the apparatus dead space in circle system are only between the Ypiece and the patient"..i believe this is very true if the fresh gas indeed can never meet the exhaled gas in the tubing and of course, we can't call the "compressed volume" in the circle system as the apparatus dead space..am i right?
BUT one of the book clearly said "in the past, the unidirectional valves have been incorporated inside the y piece to decrease the apparatus dead space effect of compliance volume" (quote from "Anesthesia Equipment : Principles and Practice")...so, the compressed volume in circle system does contribute to apparatus dead space..?
..i don't get it...this statement really contradicts the previous statement..which one is true?
i am sorry for the long post..i am very confuse about this...please help..i really want to understand this concept...
if i am misunderstanding something, please just say it to me..it may help me too 🙂
thank you,
best regards,Ketap
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