Hypoxia & Hypoxemia
Laws and Effects
Normal Values
Surprise Me
ABGs
Hemoglobin
Under Pressure
100
In this specific category of hypoxia, arterial oxygen tension PaO2 and oxygen saturation SaO2 are entirely normal, but tissue hypoxia occurs because cardiac output or localized regional blood flow is severely compromised.
What is circulatory hypoxia?
100
This law states that the amount of a gas dissolved in a liquid is directly proportional to its partial pressure.
What is Henry's Law?
100
This component represents the water vapor pressure of a 100% saturated gas at body temperature (37 degrees Celsius).
What is 47 mmHg?
100
Identify the equation above and its use.
What is the Henderson-Hasselbach equation?
100
Complete renal metabolic compensation for a chronic respiratory disorder typically requires this timeframe to fully manifest.
What is 24-48 hours?
100
This is the normal range for adult hemoglobin (Hb) concentration in blood.
What is 12- 16 g/dL?
100
Hydrostatic Pressure is a mechanism that does which of the following:
I. Pushes fluid into the interstitium
II. Is caused by cardiac issues, including left ventricular failure, fluid overload, and mitral stenosis
III. Increases pulmonary edema
What is I, II, and III?
200
2-for-1
A deficiency in this _________ molecule will lead this type of hypoxia.
What is hemoglobin and anemic hypoxia?
200
According to Fick’s Law of Diffusion, if this structural property of the alveolar-capillary membrane increases, the rate of gas diffusion will decrease.
What is the thickness of the barrier (T)?
200
The time period for which fetal hemoglobin is replaced
What is 6 months after birth?
200
This term describes a condition in which pulmonary capillary blood perfusion persists in unventilated or collapsed alveoli (V/Q = 0).
What is an absolute shunt?
200
A sudden rise in arterial carbon dioxide tension (PaCO2) with a concomitant acute fall in pH defines this clinical crisis.
What is acute ventilatory failure?
200
Each individual adult hemoglobin molecule contains this many heme groups and ferrous (Fe++) ions.
What are 4 heme groups and 4 ferrous ions?
200
At sea level, this gas constitutes approximately 78% of the Earth's atmosphere.
What is nitrogen?
300
This specific clinical condition features a normal PaO2 and SaO2 on standard blood gas analysis, but dramatically shifts the curve left and impairs oxygen delivery due to preferential binding.
What is carbon monoxide poisoning?
300
According to Graham's Law, carbon dioxide diffuses approximately this many times faster than oxygen through liquid media due to its higher solubility and lighter relative diffusion characteristics.
What is 20 times faster?
300
This is the normal physiological shunt fraction range for a healthy individual.
What is 2-5%?
**Bonus:*** What is a shunt and name what percentage would require peep and ventilation?
300
To maintain electrochemical neutrality when bicarbonate ions shift out of the red blood cell into the plasma, this shifts into the red blood cell.
What is chloride?
300
When a pH falls within the normal range, but bicarb or carbon dioxide are elevated/reduced, the condition can be called this.
What is chronic or compensated?
300
This is the normal value of carboxyhemoglobin in smokers
What is 10%?
300
While SVR measures the afterload of the left ventricle, this parallel vascular bed reflects the afterload of the right ventricle, calculated using the formula.
** Bonus: ** Name 3 things that differentiate PVR & SVR.
400
Early clinical signs of acute hypoxemia typically include tachycardia, hypertension, tachypnea, and this psychological or cognitive alteration.
What is restlessness, anxiety, or confusion (CNS irritability)?
400
This is the simplified alveolar air equation used to calculate ideal alveolar oxygen tension (PAO2).
What is PAO2 = [FIO2 x (PB - PH2O) - (PaCO2 x 1.25)] ?
400
The normal value for oxygen consumption is this
What is 250 mL/min?
400
This specific type of diffusion-limited or barrier defect impairs gas transfer primarily by increasing the diffusion distance across the alveolar-capillary membrane
What is a diffusion defect? (pulmonary fibrosis/edema)
400
Given an ABG: pH 7.50, PaCO = 29mmHg, HCO3 = 22 mEq/L, and PaO2 = 48 mmHg. This is the complete interpretation
What is uncompensated respiratory alkalosis secondary to moderate hypoxemia?
400
This intravenous medication, or reducing agent, is the primary specific pharmacological antidote for severe methemoglobinemia, reducing ferric iron back to the ferrous state.
What is methylene blue?
400
Name the pressure measured in the right atrium.
What is RAP or CVP?
** Bonus: ** Is the port on the catheter the distal or proximal port?
500
Disease states characterized by severe ventilation-perfusion mismatch or diffusion barriers typically exhibit this clinical response when low-to-moderate increases in FIO2 are administered.
What is minimal in PaO2?
500
Name the four conditions and the direction in which they shift the oxygen dissociation curve when the condition is increased.
What is temperature (right), pH (left), CO2 (right), and 2-3 DPG (right)?
500
The normal value for this is calculated by the equation above. State the normal value, what this equation measures, and the name of the equation.
What are 4-6 L/min, cardiac output, and the Fick equation?
500
In the upright human lung, regional ventilation and perfusion are both preferentially greatest in this anatomical region due to gravity and hydrostatic pressure gradients.
What are the lung bases?
500
Given an ABG: pH 7.21, PaCO2 = 70mmHg, HCO3 = 28 mEq/L, and Base Excess +2.
What is partially compensated respiratory acidosis?
500
Rust-colored blood is a reflection of this condition_____ that inhibits the binding of oxygen.
What is methemoglobinemia?
500
A patient in the medical ICU has a pulmonary artery catheter in place. As the respiratory therapist, you inflate the balloon to obtain a pulmonary artery wedge pressure (PAWP/PCWP). When properly wedged, the tip of the catheter directly reflects this chamber.
What is the left atrium?
600
This is the primary reason why mixed venous oxygen content (CvO2) decreases during states of stagnant (circulatory) hypoxia or decreased cardiac output.
Also tell me which form of hypoxia causes a higher CvO2.
What is increased oxygen extraction by the peripheral tissues due to slow capillary transit time?
And what is histotoxic hypoxia?
600
Calculate the PAO2 given:
PB = 700 mmHg
PH2O = 47 mmHg
FIO2 = 0.80
PaCO2 = 45 mmHg
What is 466.15 mmHg?
600
Your SvO2 should account for this percentage of your SaO2
What is 75%?
600
Calculate the estimated pulmonary shunt fraction given the following patient parameters:
- Hb: 15.0 g/dL
- PaO₂: 80 mmHg (SaO₂ = 95%)
- PvO₂: 36 mmHg (SvO₂ = 68%)
- PAO₂ (Alveolar O₂ tension): 150 mmHg (CcO₂ calculated or estimated near 100% saturation)
What is 17.9%?
600
Case 1: The Post-Op Patient
pH: 7.21
PaCO2: 30 mmHg
HCO3-: 12 mmol/L
PaO2: 88 mmHg
Na+: 132 mmol/L
Cl-: 98 mmol/L
Calculate the anion gap and tell me what condition this patient is facing.
What is partially compensated metabolic acidosis with an anion gap of 22 mmol/L?
** Bonus: ** Name some conditions that cause a high anion gap metabolic acidosis
- lactic acidosis
- ketoacidosis
600
Calculate the total arterial oxygen content (CaO2) given:
Hb = 14 g/dL
PaO2 = 90 mmHg
SaO2 = 0.94
What is 17.90%?
600
Given a barometric pressure (PB) of 700 mmHg and completely dry gas (PH2O = 0), this is the calculated partial pressure of oxygen (PIO2) when breathing room air (FIO2 = 0.21).
What is 147 mmHg?