Hello. For some of the moderators on here, you've probably seen my questions pop up in the LVN/PN section. That would be because I am in LVN school here in SoCal. Anyway, I have a general question regarding A&P because our instructor staff have been less than knowledgeable and moreso confused in terms of their presentation of materials relating to internal structures of the Anatomy and Physiology. I've tried to turn to some of the resources on-line but can't seem to find much on the information. Our text does a real good job at confusing rather than educating - even with self study.
The questions that I have are:
The lungs - as they sit in the chest cavity - what surrounds the lungs? layers? and the "pressure" in those layers. This became an issue when our instructor started talking about pneumothorax and chest wounds. She couldn't remember if there was pressure in the cavities and whether they the pressures were positive or negative?
What is the normal pressure of lungs if there is no puncture - or injury?
If there is some type of injury like a GSW or rib puncture, where is the chest tube insertion site? In the puncture or away from it? This is because wound care became a heated issue between her and a combat medic.
Here is an equally pressing question that was posed by our book - but some of our more "learned" instructors are at odds with our new book:
Q: The patient with respiratory acidosis will demonstrate which of the following? (More than one answer may be correct.)
1. Disorentation
2. pH of less than 7.35
3. pH of more than 7.44
4. Rapid Respirations
(The Answer according to the book is 1,2,4)
But the puzzling thing is this - within the book they give an example of Respiratory acidosis as being a person who has O.D. on tranquilizers and the breath rate of the patient is slow and shallow. It is contradicted by their example of a person who just got into a car accident and is uninjured but is freaking out. The book says that with the rapid and short breaths the person is blowing out too much CO2 and therefore, the person is in Resp Alkalosis because of the loss of "Carbonic Acid".
Are there any resources out there that can clear this up - online or book wise. I need a "Neuro-crash cart" stat
This process is reversed in the lungs. carbon dioxide must be liberated from bicarbonate so we can get rid of it. So, bicarbonate ions bind with hydrogen ions to make cabonic acid. The carbonic acid is quickly split into CO2 and H2O, and the CO2 can be released.
this will happen only w/deep, rapid resps...alveoli level.
will not happen w/shallow resps.
also keep in mind, as pH drops, parts of the brain that regulate breathing, are stimulated to produce faster and deeper breaths, which will increase the amt of co2 exhaled.
it all depends on what part of the process the acidosis is in.
this will happen only w/deep, rapid resps...alveoli level.
will not happen w/shallow resps.
also keep in mind, as pH drops, parts of the brain that regulate breathing, are stimulated to produce faster and deeper breaths, which will increase the amt of co2 exhaled.
it all depends on what part of the process the acidosis is in.
is it compensating or decompensating?
leslie
I am not sure I understand your point. The process I explained is what should happen in a normal person. If you do not have gas exchange or perfusion at the level of the alveoli, then yes this process does not happen.
However, my point was based around explaining how CO2 relates to the PH. I see people all too often simply say CO2 equals acid; however, hydrogen ions equal acid. I was trying to explain where the hydrogen comes from and how CO2 changes form if you will.
We should also know that PH change does effect the respiratory centers directly. For example, the DKA patient is in ketoacidosis; however, the presence of hydrogen ions are stimulating the breathing centers causing the rapid deep respirations.
So, while hypoxia can stimulate the respiratory centers, it is a much slower response and hydrogen ions will cause the most significant changes. This process is also much faster.
My example does not account for CO2 dissolved in plasma or CO2 that is bound to hemoglobin.
Specializes in med/surg, telemetry, IV therapy, mgmt.
co2 is the respiratory component of acid-base determination; hco3- is the metabolic component. the mnemonic rome is used to remember the relationships. it means the following:
Specializes in med/surg, telemetry, IV therapy, mgmt.
i think the op asked some very basic information. the discussion has gotten way beyond what the op was asking about.
but the puzzling thing is this - within the book they give an example of respiratory acidosis as being a person who has o.d. on tranquilizers and the breath rate of the patient is slow and shallow.
this is correct. the tranquilizers depress the central nervous system which slows the breathing. slowing the breathing means less co2 is being exchanged with oxygen in the capillaries of the alveoli of the lungs so co2 is building up in the blood because the cells continue cellular metabolism and giving off co2. the patient's ph goes down as the blood co2 levels rise. the patient goes into
respiratory acidosis
.
it is contradicted by their example of a person who just got into a car accident and is uninjured but is freaking out. the book says that with the rapid and short breaths the person is blowing out too much co2 and therefore, the person is in respiratory alkalosis because of the loss of "carbonic acid".
right again. what the patient is doing is hyperventilating. this is much different than the above scenario. it results in low co2 in the blood which disrupts the ph resulting in a high ph which is
respiratory alkalosis
.
whenever you are looking at co2 (carbonic acid) as the component determining the acid-base decision, it is always going to be about what is going on in the lungs, or respiratory system. the ph will tell you if you've got acidosis or alkalosis and the co2 tells you it's cause is the respiratory track.
don't know why your instructors are at odds with that.
I do not think the instructors are at odds with these concepts. From what I gather, the OP simply has not been taught the basics of acid/base balance. It seems like the OP has a very basic level of understanding but is expected to understand material that is much more advanced than the OP's core level of knowledge. I suspect this is a possible failure on the instructors part to properly educate the student.
leslie :-D
11,191 Posts
this will happen only w/deep, rapid resps...alveoli level.
will not happen w/shallow resps.
also keep in mind, as pH drops, parts of the brain that regulate breathing, are stimulated to produce faster and deeper breaths, which will increase the amt of co2 exhaled.
it all depends on what part of the process the acidosis is in.
is it compensating or decompensating?
leslie