
A-aDo2: A-a gradient,

norm 5-10 mmHg on .21, 30-60 on 100%,
>350mech support, <350 weaning.
Represents potential to Oxygenate vs. the
amount of O2 in the artery. Every 50mmHg is
approx. 2 percent shunt above norm of 2-5%

Increased A-a= SHUNT


a/A ratio: PaO2/PAO2 norm is 90%,
>35%weaning, reflects efficiency of
oxygenation as a percentage, <74% shunt,
V/Q mismatch or diffusion defect




Anion Gap= the difference in the measured
cations and the measured anions in serum,
plasma, or urine.
Used to assess Metabolic Acidosis or
alkalosis, normal around 8-16 mEq/L. Use
MUDPILES to determine cause of metabolic
acidosis (high gap)
= ( [Na+] ) − ( [Cl−]+[HCO3−] ) without
potassium
= ( [Na+]+[K+] ) − ( [Cl−]+[HCO3−] ) with
potassium



CaO2: norm 20 vol%
(Hbx1.34)SaO2 + (PaO2x.003) total amount
of O2 carried in 100ml of blood, combined
content of O2 carried on Hb and dissolved in
plasma,
(can be reduced by <Hb, anemia or <CO)




CvO2: (Hb x 1.34)SvO2 + (PvO2 x .003)
norm is 15 vol%, represents the value of O2 in
blood returning to the right side of the heart
after tissues have oxygenated.
C(a-v)O2 = arterial to mixed venous oxygen
content difference
Determines how well the tissues take up O2



VO2: O2 consumption,
norm is 250mL/O2/L/min,
[C(a-v)O2 x QT] x 10, the amount of O2
consumed by the body per liter of blood per
minute.


DO2: O2 Delivery, (CaO2 x CO) x 10, norm is
1000mL/O2/min
The ability of oxygen to tissues based on
cardiac output and Hb





No more than ½ the internal diameter of ETT
or else improper entrainment.
French divided by 3.14 = size in mm. normal
adult sizes 12 - 14 fr
O.D. of catheter should not exceed 1/2 I.D.of
airway
(1) to determine size of suction catheter for
given ET tube: ETT size / 2 then x 3.14
(2) always round down – i.e. 7/2 x 3.14 =
10.99, use a 10 French




Cardiac Output (CO) = amt of blood ejected
from the heart per minute
CO= Stroke Volume X heart rate
normal 4-8 L/min
QT = cardiac output
Cardiac Index (CI)= amount of blood pumps
per minute based on body weight CI=
CO/BSA, normal 2.4-4 L/min








QS/QT: Pulmonary Shunt equation
(CcO2-CaO2)/(CcO2-CvO2)
Norm 2-3%,
>20% vent indication,
<20% weaning,
>30% is life threatening.
Measures % of QT not exposed to ventilation,
shunts caused by atelectasis, edema, pneumonia,
pneumothorax, obstructions
CcO2: Content of pulm capillary blood oxygen at
100% FIO2, (Hbx1.34)1 + (PAO2x.003) used in
shunt equation

Order:
◦
◦
◦
◦
◦
◦
◦
◦
◦
◦
◦
◦
Creatine and BUN
Electrolytes
ABG
Vitals
Glucose Level
GRF
I/O
Specific gravity of urine
Albumin
Anion Gap
Renal ultrasound
CBC (Hb)

A serum creatinine test measures the amount of
creatinine in the blood and shows how well your
kidneys are working. Creatinine is a breakdown
product of creatine, which is formed when your
body metabolizes food. Creatinine is taken out of
your body by your kidneys and then passed out
of your body in urine. Creatinine is produced in
your body at a consistent rate, it is not affected
by your diet or normal physical activities. If your
kidneys are damaged, the level of creatinine in
your blood increases.
Normal Results: .8 to 1.4 mg/dl

BUN test is used to check kidney function. Urea
nitrogen is what forms when protein breaks down.
Urea is a waste product made when protein is broken
down in your body. Urea is made in the liver and
passed out of your body in the urine. Like creatinine,
your BUN results can help your doctor determine how
well your kidneys are working. For people with liver
disease, the BUN level may be low even if the kidneys
are normal. Kidney disease or blockage of the flow of
urine from your kidney causes both BUN and
creatinine levels to rise.
Normal Results: 7 to 20 mg/dl

A BUN-to-creatinine ratio can help your doctor
check for problems, such as dehydration, that
may cause abnormal BUN and creatinine levels.
High BUN-to-creatinine ratios occur with sudden
(acute) kidney failure, which may be caused by
shock or severe dehydration. A low BUN-tocreatinine ratio may be associated with a diet low
in protein, a severe muscle injury called
rhabdomyolysis, pregnancy, cirrhosis or
syndrome of inappropriate antidiuretic hormone
secretion (SIADH).
Normal Results: 10:1 to 20:1


Albumin
The albumin test measures the amount of albumin in
serum, the clear liquid portion of blood and determines if
the liver is making enough albumin. This test helps in
determining if a patient has liver disease or kidney
disease, or if not enough protein is being absorbed by the
body. Albumin is one of the two major proteins in the
blood, the other is Globulin. Albumin also helps carry
some medicines and other substances through the blood
and is important for tissue growth and healing. Because
albumin is made by the liver, decreased serum albumin
may result from liver disease. It can also result from
kidney disease which allows albumin to escape into the
urine. Decreased albumin may also be explained by
malnutrition or a low protein diet.
Normal Results: 3.4 to 5.4 g/dl

This test measures the amount of Calcium in
your blood, not the calcium in your bones. The
body needs it to build and fix bones and teeth,
help nerves work, make muscles contraction,
help blood clot, and help the heart to work. The
Calcium test screens for problems with the
parathyroid glands or kidneys, certain types of
cancers and bone problems, inflammation of the
pancreas (pancreatitis), and kidney stones.
Normal Results: 8.5 to 10.2 mg/dl



The serum chloride test measures the amount of chloride in the
fluid portion of the blood. Chloride is a negatively charged
molecule known as an electrolyte. It works with other
electrolytes, such as potassium, salt (sodium), and carbon
dioxide (CO2), to help keep the proper balance of body fluids
and maintain the body's acid-base balance. Most of the chloride
in your body comes from the salt (sodium chloride) you eat.
Chloride levels can be used to help monitor high blood pressure,
heart failure and kidney disease. High levels of chloride, known
as hyperchloremia, typically indicate dehydration, metabolic
acidosis and other conditions. Decreased levels of chloride,
known as hypochloremia, can indicate kidney disorder, Addison's
disease, congestive heart failure and other conditions.
Normal Results: 96 to 106 mEq/L



This test measures the amount of potassium in the blood. Potassium is both an
electrolyte and a mineral. It helps keep the water (the amount of fluid inside and
outside the body's cells) and electrolyte balance of the body. Potassium levels
often change with sodium levels. When sodium levels go up, potassium levels go
down, and when sodium levels go down, potassium levels go up.
Abnormal potassium levels may cause symptoms such as muscle cramps or
weakness, nausea, diarrhea, frequent urination, dehydration, low blood pressure,
confusion, irritability, paralysis, and changes in heart rhythm.
High blood potassium levels may be caused by damage or injury to the kidneys.
This prevents the kidneys from removing potassium from the blood normally. The
most common cause of high potassium levels is kidney disease. Because
potassium is important to heart function, patients should order this test if they
have signs of high blood pressure or heart problems.
Low levels of potassium cause increased heart muscle activity, which can lead to
an irregular heartbeat. Both high and low levels can lead to a heart attack in some
cases.
Normal Results: 3.7 to 5.2 mEq/L

A sodium test determines the level of sodium within the blood. Sodium is both an electrolyte
and mineral. It helps maintain the water (the amount of fluid inside and outside the body's
cells) and electrolyte balance of the body. Sodium is also important in how nerves and muscles
work. A small percentage is lost through stool and sweat.
Normal Results: 135 to 145 mEq/L
For greater-than-normal sodium levels:
High levels of sodium can increase the chance of high blood pressure.


If your total body water is low, high sodium levels may be due to fluid loss from excessive
sweating, diarrhea, use of diuretics or burns.

If your total body water is normal, high sodium levels may be due diabetes insipidus or too
little of the hormone vasopressin.

If your total body water is high, high sodium levels may indicate hyperaldosteronism, Cushing
syndrome, or a diet that's too high in salt or sodium bicarbonate.
For lower-than-normal sodium levels:
Low total body water and sodium levels may be due to dehydration, vomiting, diarrhea, over
diuresis, or ketonuria.






Lactic acidosis is a physiological condition characterized
by low pH in body tissues and blood accompanied by the
buildup of lactate
Considered a distinct form of metabolic acidosis.
The condition typically occurs when cells receive too little
oxygen
For example during vigorous exercise. In this situation,
impaired cellular respiration leads to lower pH levels.
Simultaneously, cells are forced to metabolize glucose
anaerobically, which leads to lactate formation.
Therefore, elevated lactate is indicative of tissue hypoxia,
hypoperfusion, and possible damage.
Lactic acidosis is characterized by lactate levels
>5 mmol/L and serum pH <7.35.
Causes, incidence, and risk factors
 The most common cause of lactic acidosis is intense exercise.
However, it can also be caused by certain diseases, such as:
 AIDS
 Cancer
 Kidney failure
 Respiratory failure
 Sepsis
Symptoms
 Nausea
 Weakness
 Signs and tests
 Blood tests to check electrolyte levels
 Treatment
 The main treatment for lactic acidosis is to correct the
medical problem that causes the condition. Oxygen

Patients will require high levels of Oxygen,
often requiring mechanical ventilation. They
will also demonstrate with increase VA to
compensate


The anion gap is the difference in the
measured cations and the measured anions in
serum, plasma, or urine.
The magnitude of this difference (i.e. "gap")
in the serum is often calculated in medicine
when attempting to identify the cause of
metabolic acidosis. If the gap is greater than
normal, then high anion gap metabolic
acidosis is diagnosed.






With potassium
It is calculated by subtracting the serum
concentrations of chloride and bicarbonate
(anions) from the concentrations of sodium and
potassium (cations):
= [Na+] + [K+] − [Cl−] − [HCO3−]
Without potassium (Daily practice)
However, the potassium is frequently ignored
because potassium concentrations, being very
low, usually have little effect on the calculated
gap. This leaves the following equation:
= [Na+] − [Cl−] − [HCO3−]



In normal health there are more measurable
cations compared to measurable anions in the
serum; therefore, the anion gap is usually
positive.
Because we know that plasma is electro-neutral
we can conclude that the anion gap calculation
represents the concentration of unmeasured
anions.
The anion gap varies in response to changes in
the concentrations of the above-mentioned
serum components that contribute to the acidbase balance. Calculating the anion gap is
clinically useful, as it helps in the differential
diagnosis of a number of disease states.










"Mudpiles"
The mnemonic MUDPILES is commonly used to remember
the causes of increased anion gap metabolic acidosis
M-Methanol
U-Uremia (chronic renal failure)
D-Diabetic ketoacidosis
P-Propylene glycol ("P" used to stand for Paraldehyde but
substance is not commonly used today)
I-Infection, Iron, Isoniazid
L-Lactic acidosis
E-Ethylene glycol (Note: Ethanol is sometimes included in
this mnemonic as well, although the acidosis caused by
ethanol is actually primarily due to the increased
production of lactic acid found in such intoxication.)
S-Salicylates







Another frequently used mnemonic is
KARMEL.
K-Ketoacidosis
A-ASA
R-Renal failure
M-Methanol
E-Ethylene glycol
L-Lactic acidosis





A 23-year-old woman with gastroenteritis
experiences nausea and vomiting. Aterial
blood gas analysis is done 1 hour after the
onset of symptoms. Which of the following
sets of blood gases is most likely.
A pH 7.30; PCO2 50; HCO3- 24
B pH 7.28; PCO2 40; HCO3- 18
C pH 7.56; PCO2 40; HCO3- 35
D pH 7.51; PCO2 50; HCO3- 35



Choice D is the best answer.
1. Vomiting causes loss of stomach acid
leading to metabolic alkalosis.
The rise in pH will inhibit the peripheral
chemoreceptor for pH located in the carotid
bodies leading to hypoventilation (increased
PCO2), which is compensatory.





A 35-year-old man with type 1 diabetes is admitted
to the emergency department after being found
unconscious and unresponsive at home. His breath
has a "fruity" odor. His wife told the EMTs that his
diabetes had been "out of control" lately and that he
has no other medical problems. His breathing is
deep and rapid. An arterial blood sample is taken for
analysis. Which of the following sets of arterial blood
gases is most likely.
A pH 7.00; PCO2 50; HCO3- 12
B pH 7.22; PCO2 30; HCO3- 12
C pH 7.56; PCO2 40; HCO3- 35
D pH 7.51; PCO2 45; HCO3- 35

Choice B is the best answer. The presentation is
consistent with ketoacidosis (ketones are volatile
acids that are eliminated via both kidneys and
lungs). The overutilization of fats for metabolism
leads to ketoacidosis, a metabolic acidosis. The
low pH stimulates the carotid pH receptor leading
to hyperventilation (lower PCO2) which is
compensatory. recall that according to the
Henderson-Hasselbalch equation, pH = 6.1 + log
[HCO3]/PCO2 x αlpha. Compensation is always
aimed at restoring the ratio HCO3/PCO2 back to
a normal value, so if HCO3 decreases, PCO2 must
decrease via hyperventilation to provide
compensation.









CXR
BNP
ABG
Cholesterol
EKG/Echocardiogram
Electrolytes
CBC
Vitals
Tx: O2, Bipap, Diuretics, Inotropics

BNP is a substance secreted from the
ventricles or lower chambers of the heart in
response to changes in pressure that occur
when heart failure develops and worsens. The
level of BNP in the blood increases when heart
failure symptoms worsen, and decreases
when the heart failure condition is stable. The
BNP level in a person with heart failure – even
someone whose condition is stable – is higher
than in a person with normal heart function.

Typically associated with CHF, depending on
the patient often requires positive pressure
for associated pulmonary edema. Typically
non-invasive ventilation








Vitals
MONA
EKG
Echo
Cardiac Enzymes
Electrolytes
CBC
Tx: Stent, O2, CABG, Fibrolytic therapy



Cardiac enzyme studies measure the levels of the
enzyme creatine phosphokinase (CPK, CK) and the
protein troponin in the blood.
Low levels of these enzymes and proteins are
normally found in your blood, but if your heart
muscle is injured, such as from a heart attack, the
enzymes and proteins leak out of damaged heart
muscle cells, and their levels in the bloodstream rise.
Because some of these enzymes and proteins are also
found in other body tissues, their levels in the blood
may rise when those other tissues are damaged.
Cardiac enzyme studies must always be compared
with your symptoms, your physical examination
findings, and electrocardiogram (EKG, ECG) results.


A liver (hepatic) function panel is a blood test
to check how well the liver is working. This
test measures the blood levels of total
protein, albumin, bilirubin, and liver
enzymes. High or low levels may mean that
liver damage or disease is present.
The liver serves several important functions
in the body, including changing nutrients into
energy for the body and breaking down toxic
substances.


Elevated liver enzymes may indicate inflammation or
damage to cells in the liver. Inflamed or injured liver
cells leak higher than normal amounts of certain
chemicals, including liver enzymes, into the
bloodstream, which can result in elevated liver
enzymes on blood tests.
The specific elevated liver enzymes most commonly
found are:
◦ Alanine transaminase (ALT)
◦ Aspartate transaminase (AST)

Elevated liver enzymes may be discovered during
routine blood testing. In most cases, liver enzyme
levels are only mildly and temporarily elevated. Most
of the time, elevated liver enzymes don't signal a
chronic, serious liver problem.
Acites, decreased
sensorium



Albumin is a protein made specifically by the
liver, It is the main constituent of total
protein; the remaining fraction is called
globulin (including the immunoglobulins).
Albumin levels are decreased in chronic liver
disease, such as cirrhosis. It is also decreased
in nephrotic syndrome, where it is lost
through the urine.
Poor nutrition or states of impaired protein
catabolism, may also lead to
hypoalbuminaemia.




Since the Prothrombin time test or PT test evaluates the
ability of blood to clot properly, it can be used to help
diagnose bleeding. When used in this instance, it is often
used in conjunction with the PTT to evaluate the function
of all coagulation factors.
Occasionally, the test may be used to screen patients for
any previously undetected bleeding problems prior to
surgical procedures.
The International Normalized Ratio (INR) is used to
monitor the effectiveness of blood thinning drugs such as
warfarin (COUMADIN®).
These anti-coagulant drugs help inhibit the formation of
blood clots. They are prescribed on a long-term basis to
patients who have experienced recurrent inappropriate
blood clotting. This includes those who have had heart
attacks, strokes, and deep vein thrombosis (DVT).




Metabolic encephalopathy is temporary or permanent damage to
the brain due to lack of glucose, oxygen or other metabolic
agent, or organ dysfunction. Most cases occur when the liver
cannot act normally to remove toxins from the bloodstream
during an acute illness, but it can also be caused by a toxic
overdose, or other systemic disease.
Causes
Metabolic encephalopathy occurs during significant metabolic
derangements, after some types of poisoning, and during
diseases such as cirrhosis or hepatitis that slow or stop liver
function, or diabetes, heart or renal failure.
It can also happen during medical conditions that cause blood
circulation to bypass the liver. These problems keep the liver
from removing toxins like ammonia, which build up in the blood
as part of normal metabolism. High levels of these toxins can
temporarily or permanently damage the brain, causing metabolic
encephalopathy.


Patients will require intubation for airway
protection
Risk for Sepsis



Disseminated intravascular coagulation (DIC) is not a
specific diagnosis, and its presence always indicates
another underlying disease.
Disseminated intravascular coagulation (DIC) is
characterized by a systemic activation of the blood
coagulation system, which results in the generation
and deposition of fibrin, leading to microvascular
thrombi in various organs and contributing to the
development of multiorgan failure.
Consumption and subsequent exhaustion of
coagulation proteins and platelets, due to the
ongoing activation of the coagulation system, may
induce severe bleeding complications, although
microclot formation may occur in the absence of
severe clotting factor depletion and bleeding.