Final Exam Flashcards
What are the PAO₂, PaO₂, CaO₂, PvO₂, CvO₂ values & will ↑FiO₂ help for low PAO₂?
All low & Yes
What are the PAO₂, PaO₂, CaO₂, PvO₂, CvO₂ values & will ↑FiO₂ help for pulmonary edema?
- Normal PAO₂
- Low PaO₂, CaO₂, PvO₂ & CvO₂
- Yes ↑FiO₂ helps
What are the PAO₂, PaO₂, CaO₂, PvO2, CvO₂ values & will ↑FiO₂ help for R to L shunt?
- Normal PAO₂,
- Low PaO₂, CaO₂, PvO2, CvO₂
- No, ↑FiO₂ will not help
What are the PAO₂, PaO₂, CaO₂, PvO₂, CvO₂ values & will ↑FiO₂ help for V/Q mismatch or dead space?
- Normal PAO₂
- Low PaO₂, CaO₂, PvO₂ & CvO₂
- Yes ↑FiO₂ helps
What are the PAO₂, PaO₂, CaO₂, PvO₂, CvO₂ values for anemic hypoxia or carbon monoxide poisoning? Will ↑FiO₂ help?
- Normal PAO₂, PaO₂
- Low CaO₂, PvO₂, CvO₂
- No, ↑FiO₂ will NOT help
What are the PAO₂, PaO₂, CaO₂, PvO₂, CvO₂ values & will ↑FiO₂ help for CO poisoning?
- Normal PAO₂, PaO₂
- Low CaO₂, PvO₂, CvO₂
- ↑FiO₂ might help but takes time
What are the PAO₂, PaO₂, CaO₂, PvO₂, CvO₂ values & will ↑FiO₂ help for low cardiac output?
- Normal PAO₂, PaO₂, CaO₂.
- Low PvO₂ & CvO₂
- No
What are the PAO₂, PaO₂, CaO₂, PvO₂, CvO₂ values & will ↑FiO₂ help for histotoxic hypoxia?
Normal PAO₂, PaO₂, CaO₂. High PvO₂, CvO₂ & No
What is the formula to calculate how much HCO₃⁻ to give?
Base deficit x ECF (ECF= 14L)
How is the anion gap calculated?
Na⁺ − (Cl⁻ + HCO₃⁻)
What is the normal anion gap?
12 mEq/L or mmol/L
The anion gap exists mostly due to?
- Albumin not being account for.
- Albumin has a (-) charge
What can lead to metabolic acidosis w/ increased anion gap?
- Ketoacidosis & Lactic acidosis
- Methanol (CH₃OH)
- EtOH
- ASA
- Ammonium chloride (ammoniac, looks like white salt crystals)
- Ethylene glycol [antifreeze (CH₂OH)₂ ]
What diseases or states can lead to ketoacidosis?
DM, EtOH, starvation
What diseases or states can lead to lactic acidosis?
- Hypoxemia
- anemia
- carbon monoxide
- septic or cardiac shock
What can lead to metabolic acidosis with normal anion gap?
- Diarrhea
- pancreatic fluid loss
- renal tubular acidosis
What are the bicarb & chloride levels in metabolic acidosis w/ normal anion gap?
HCO₃⁻ is low and Cl⁻ is increased.
How are pH, PCO₂ & HCO₃⁻ affected in uncompensated resp. acidosis?
- pH: ↓↓
- PCO₂: ↑↑
- HCO₃⁻: ↑
How are pH, PCO₂ & HCO₃⁻ affected in uncompensated resp. alkalosis?
- pH: ↑↑
- PCO₂: ↓↓
- HCO₃⁻: ↓
How are pH, PCO₂ & HCO₃⁻ affected in uncompensated metabolic alkalosis?
- pH: ↑↑
- PCO₂: –
- HCO₃⁻: ↑↑
How are pH, PCO₂ & HCO₃⁻ affected in uncompensated metabolic acidosis?
- pH: ↓↓
- PCO₂: –
- HCO₃⁻: ↓↓
How are pH, PCO₂ & HCO₃⁻ affected in respiratory & metabolic acidosis?
- pH: ↓↓
- PCO₂: ↑↑
- HCO₃⁻: ↓
How are pH, PCO₂ & HCO₃⁻ affected in respiratory & metabolic alkalosis?
- pH: ↑↑
- PCO₂: ↓↓
- HCO₃⁻: ↑
What are common causes of metabolic alkalosis?
- Loss of H⁺ ions(vomiting, gastric fistula, diuretics)
- overproduction/treatment with steroids(aldosterone or mineralocorticoids)
- excess IV or ingestion of Bicarb or other bases.
What are common causes of metabolic acidosis?
- Ingestion of drugs or toxins (methanol, ethanol, ethylene glycol)
- salicylates (ASA)
- ammonium chloride
- diarrhea
- pancreatic fistula
- renal dysfunction
What are some common causes of respiratory alkalosis?
- Anxiety, hyperventilation
- meningitis, cerebrovascular disease, tumors
- salicylates, progesterone
- bacteremia, fever
- acute asthma, PE
- hypoxia, high altitude
How does high altitude affect the respiratory system?
A decrease in PO₂ → ↑ respiratory drive → ↓PCO₂
Given this formula, HA ↔ H⁺ + A⁻, what is the conjugated base?
A⁻
What is the acid concentration of protons with a pH of 7.00?
100 nmol/L
What is the acid concentration of protons with a pH of 7.40?
40 nmol/L
What is the acid concentration of protons with a pH of 7.70?
20 nmol/L
What is the central acid/base formula?
- CO₂ ↔ CO₂ + H₂O ↔↔↔↔↔↔ H₂CO₃ ↔ H⁺ + HCO₃⁻
- (gas phase) (liquid phase) (carbonic anhydrase)
What are protons measured (units) in?
nmol/L
A salicylate overdose can lead to what?
- Respiratory alkalosis (ASA OD activates brainstem to increase RR)
- Metabolic acidosis
What nerve innervates the cricothyroid muscle?
The external branch of the Superior Laryngeal nerve
The Foramen of the _____nerve is located in the ____ membrane?
- Internal branch of the laryngeal nerve
- thyroid membrane
When placing an emergent airway, between which specific muscle(s) is the incision made?
Straight parts of the cricoid muscle
What muscle(s) have no effect on the Rima Glottis?
Cricothyroid muscle & Vocalis muscles
What muscle(s) adduct the vocal cords?
- Thyroarytenoid muscle
- Transverse arytenoid muscle
- Lateral cricoarytenoid muscles
Which muscles pull the arytenoids medial?
Transverse arytenoid muscles
The inferior horn of the thyroid cartilage attaches to the___?
Articular facet of the cricoid cartilage
Name all muscles that attach to the arytenoid cartilages?
- Transverse & oblique arytenoid muscles
- Thyroarytenoid muscle
- Lateral & posterior cricoarytenoid muscles
- Vocalis muscles
The conus elasticus connects to?
The vocal ligament & arch of cricoid cartilage
What innervates sensory information for the trachea?
The inferior laryngeal nerves
Which muscle is not innervated by the inferior laryngeal nerve?
The cricothyroid muscle
The right recurrent laryngeal nerve passes under the___?
Brachiocephalic artery
- Also called the brachiocephalic trunk or Innominate artery
What is another name for the brachiocephalic artery?
Innominate artery
The left recurrent laryngeal nerve passes in between which two objects?
The aortic arch and left bronchi
What sits in between tracheal rings?
The cricotracheal ligaments
What is more superior, the true or false vocal cords?
False vocal cords are superior
Relaxing the cricothyroid muscle leads to what?
The thyroid cartilage moves upwards
Which laryngeal muscle can be seen without cutting someone open?
The cricothyroid muscle
What muscle contracts during swallowing?
Cricothyroid muscle
Applying too much cricoid pressure can lead to what?
If air cannot escape then esophageal sphincter can be damaged
Being 500 feet under sea level increases the pressure on someone by how many atm?
15 atm’s
- Sea level is 1 atm, so there is a 15 atm “increase” in pressure.
Being 100 feet under sea level increases the pressure on someone to how many atm?
3 atm’s
What acid/base disorder is below?
pHa:7.25
PaCO2: 50mmHg
[HCO3⁻]: 26 mEq/L
PaO2: 70mmHg
Anion gap: 11 mEq/L
Uncompensated respiratory acidosis (Lange 8-1)
What acid/base disorder is below?
pHa:7.47
PaCO2: 46mmHg
[HCO3]: 33 mEq/L
PaO2: 85mmHg
Anion gap: 9 mEq/L
Compensated metabolic alkalosis (Lange 8-2)
What acid/base disorder is below?
pHa: 7.60
PaCO2: 20mmHg
[HCO3]: 20 mEq/L
PaO2: 110mmHg
Anion gap: 12 mEq/L
Uncompensated respiratory alkalosis (Lange 8-3)
What acid/base disorder is below?
pHa: 7.34
PaCO2: 65mmHg
[HCO3]: 40 mEq/L
PaO2: 65mmHg
Anion gap: 11 mEq/L
Chronic respiratory acidosis (Lange 8-4)
What acid/base disorder is below?
pHa: 7.25
PaCO2: 30mmHg
[HCO3]: 15 mEq/L
PaO2: 95mmHg
Anion gap: 10 mEq/L
Metabolic acidosis w/ renal compensation (Lange 8-5)
What acid/base disorder is below?
pHa: 7.25
PaCO2: 30mmHg
[HCO3]: 15 mEq/L
PaO2: 95mmHg
Anion gap: 25 mEq/L
Metabolic acidosis with respiratory compensation (Lange 8-6)
What could be the causes (3) for the ABG below?
pHa:7.25
PaCO2: 50mmHg
[HCO3⁻]: 26 mEq/L
PaO2: 70mmHg
Anion gap: 11 mEq/L
- Acute respiratory depression
- Actue airway obstruction
- Hypoventilation via ventilator
What could be the cause (1) of the ABG below?
pHa: 7.25
PaCO2: 30mmHg
[HCO3]: 15 mEq/L
PaO2: 95mmHg
Anion gap: 10 mEq/L
Diarrhea
What could be the causes (4) of the ABG below?
pHa: 7.25
PaCO2: 30mmHg
[HCO3]: 15 mEq/L
PaO2: 95mmHg
Anion gap: 25 mEq/L
- Lactic acidosis
- ketoacidosis
- renal retention of anions
- ingestion of organic anions like salycylates, ethylene glycol, ethanol & methanol
What could be the cause (1) of the ABG below?
pHa:7.47
PaCO2: 46mmHg
[HCO3]: 33 mEq/L
PaO2: 85mmHg
Anion gap: 9 mEq/L
After 10mins of vomiting
What could be the causes (3) of the ABG below?
pHa: 7.60
PaCO2: 20mmHg
[HCO3]: 20 mEq/L
PaO2: 110mmHg
Anion gap: 12 mEq/L
- Psychological hyperventilation (anxiety)
- Drug induced hyperventilation
- Hyperventilation via ventilator
What could be the cause (1) of the ABG below?
pHa: 7.34
PaCO2: 65mmHg
[HCO3]: 40 mEq/L
PaO2: 65mmHg
Anion gap: 11 mEq/L
COPD
Chronic bronchitis is what kind of disease?
An obstructive disease
A 68-year-old man complains of difficulty breathing. He says he has had the problem for a long time—in fact, he can’t remember when it started—and it seems to be getting worse. He coughs all the time and constantly produces sputum upon arising. He says that he has smoked at least one pack of cigarettes a day since he was 20 years old. He does appear to be somewhat cyanotic.
The patient’s dynamic lung volumes are not improved after the administration of a bronchodilator. The patient’s disease is most likely?
COPD, primarily chronic bronchitis
Metabolic acidosis with a normal gap is usually due to?
- Loss of Bicarb (Diarrhea)
- Chloride retention from rental tubular necrosis
Carbon monoxide, anemia, strenuous exercise & ARDS can lead to what?
Lactic acidosis → Metabolic Acidosis w/ increased Anion Gap
What is our value for ECF chloride?
106
What is our value for ECF sodium?
142
What is our value for ECF Bicarb?
24
A base deficit is considered?
A decrease in HCO₃⁻
How would one know how much HCO₃⁻ to give?
- Take the HCO₃⁻ deficit and multiply that by ECF fluid, which is 14L
- PaCO₂ has to be 40 mmHg
How much O2 is bound in 1 dL of arterial blood, with a PaO₂ of 100 mmHg, Hb of 15 g/dL & saturation of 100%?
19.7mL O₂/dL
What is histotoxic hypoxia?
The tissues are unable to use the oxygen.
What are the PO₂ & PCO₂ at the bottom of the lung, per lecture?
- PO₂: 90 mmHg
- PCO₂: 42 mmHg
What are the PO₂ & PCO₂ at the top of the lung, per lecture?
- PO₂: 130 mmHg
- PCO₂: 30 mmHg
What are the alveolar PAO₂ & PACO₂ in a V/Q ratio of 0?
- PAO₂: 40 mmHg
- PACO₂: 45 mmHg
The “R” ratio is affected by what?
Carbs, proteins & fat metabolism
How do carbs & fats affect CO₂ & the RER?
- Carbs: produces lots of CO₂ → an increased R value
- Fats: ↓CO₂ → a decreased R value
What factors lead to an increase in the EtCO₂ waveform?
- Fever
- Bicarb infusion
- ↑ cardiac output
- ↑ blood pressure
- Hypoventilation
- Malignant hyperthermia
- Release of tourniquet (the static venous blood will have a lot of CO₂ in it)
- Inflating abdominal cavity with CO₂
What factors would lead to a decrease in the EtCO₂ waveform
- Hypothermia
- ↓ cardiac output
- ↓ blood pressure
- PE
- Hyperventilation
- Extubation
- Airway obstruction
- Disconnected circuit
- Alveolar dead space development
- Esophageal intubation
What is happening in the following EtCO₂ waveforms?
See pic
What is happening in the following EtCO₂ waveforms?
See pic
What EtCO₂ waveform has a shark fin appearance?
Bronchospam
Describe the V/Q in a supine sedated & paralyzed Pt.
- The diaphragm pushes into the lungs, more at the bottom
- The V/Q ratio will be best in the anterior/non-dependent areas
- Lung volume will be ~ 1 L
What happens to chest wall compliance in the supine position?
Compliance decreases
The anterior scalene muscle connects to?
- C3 - C6 & the 1st rib
The middle scalene muscle connects to the?
C3 - C7 & the 1st rib
The posterior scalene muscle connects to the?
C5 - C7 & the 2nd rib
What is the connection point of the inferior & superior laryngeal nerves called?
Galen’s anastomosis
What enters thru the foramen in the Thyrohyoid membrane?
- The internal branch of the superior laryngeal nerve
- Also the Superior laryngeal artery & vein
The superior laryngeal nerve innervates what muscle?
The cricothyroid muscle
How would an injury to the external branch of superior laryngeal nerve affect one’s voice?
It would result in a hoarseness
What nerve does the Laryngeal nerve branch off of?
The vagus nerve
At what anatomical landmark does the Superior laryngeal nerve branch?
At the hyoid bone
What is the connection between cricoid & inferior horn of the thyroid called?
The Cricothyroid joint
What is the function of the cricothyroid muscle?
Tenses/tightens the vocal cords
What is the function of the Thyroarytenoid muscle?
Relaxes the vocal cords (Thy relax)
Strong bases want what?
To accept H⁺
When will proton activity be the greatest?
With a low pH, high CO₂ & normal HCO₃⁻
How does aldosterone affect H⁺?
Aldosterone gets rid of K⁺ & H⁺
What is a person’s total arterial O₂ content with a Hb of 15g/dL & a PaO₂ of 250 mmHg?
- 15 x 1.34= 20.1 mL O₂/dL
- 250 mmHg x 0.003 mL O₂/dL/mmHg= 0.75 mL O₂/dL
- Total= 20.85 mL O₂/dL
Every ____ of depth the pressure rises by 1 atm?
33ft or 10 meters
___ atm and an FiO₂ of ____ will cause CNS toxicity & lead to seisures?
- 4 atm
- FiO₂ of 100%
Regular diving cylinders will contain what kind of O₂ concentration?
21%
Besides helping in decompression therapy, what increases in hyperbaric chamber therapy?
The dissolved O₂ content increases
What is the safety cutoff for hyperbaric chambers?
4 atm or 3,000 mmHg
Having too much oxygen around can lead to the formation of what?
Free radicals like:
- Superoxide: O₂⁻
- Peroxynitrite: OONO⁻ (combination of NO & O₂⁻)
What usually contains Superoxide?
Superoxide dismutase (SOD)
What helps with detoxification of EtOH?
NAC
What happens when there is too much superoxide and/or peroxynitrite?
They attach proteins & DNA
How is an estimated A-a gradient calculated.
(Age + 10) / 4
A decreased R value will affect a person how?
It decreases the respiratory effort
What is the max PACO₂ we can handle for a short period of time?
80 mmHg
How much CO₂ does a person produce per minute?
200 - 225 mL/min
How much O₂ does an average person consume per minute?
250 mL/min
What are the top & bottom pleural pressures at RV?
- Top: - 2.2 cmH₂O
- Bottom: + 4.8 cmH₂O
What are the top & bottom pleural pressures at FRC?
- Top: - 8.5 cmH₂O
- Bottom: - 1.5 cmH₂O
How is Hb saturation calculated?
O₂ bound to Hb divided by O₂ capacity of Hb
Is H₂CO₃ a strong/ weak acid or a strong/weak base?
Carbonic acid is a weak acid
Is HCO₃⁻ a strong or weak acid/base?
Bicarb is a strong base
What is the normal P50 value?
26.5 mmHg
What is the state for ferrous?
Fe²⁺
What is the state for ferric?
Fe³⁺
Is ferric or ferrous the oxidized state?
Ferric is
How does aldosterone affect pH
Aldosterone stimulates H⁺ secretions & retains HCO₃⁻, which leads to an increase in pH.