ABGS AND RESPIRATORY COMPLETE
EXAM REVIEW WITH FULL SOLUTIONS
●● What is the normal range for oxygen saturation?
Answer: 95-100%, ideally above 96%.
●● What does PaO2 measure?
Answer: The amount of oxygen dissolved in the plasma.
●● What is the normal range for PaO2?
Answer: Approximately 80-100 mmHg.
●● What indicates severe hypoxemia in terms of PaO2?
Answer: A PaO2 below 40 mmHg.
●● How can expected PaO2 be estimated?
Answer: By multiplying the FiO2 percentage by approximately 5.
●● What is the first step in oxygen delivery for low oxygen levels?
Answer: Supplemental oxygen may be required, starting from a nasal
cannula.
,●● What is the role of carbon dioxide in acid-base balance?
Answer: It combines with water to form carbonic acid, which is
regulated by the lungs and kidneys.
●● What are arterial blood gases (ABGs)?
Answer: They provide important information about pH, carbon dioxide,
bicarbonate, PaO2, and oxygen saturation.
●● What is the normal pH range for blood?
Answer: 7.35-7.45.
●● What happens to pH when CO2 levels increase?
Answer: pH decreases, leading to acidosis.
●● What is respiratory acidosis?
Answer: Occurs when pH is below 7.35 and CO2 is above 45 mmHg.
●● What causes respiratory alkalosis?
Answer: Hyperventilation, anxiety, pregnancy, and strenuous exercise.
●● What is metabolic acidosis?
Answer: Occurs when pH is below 7.35 and bicarbonate is below 22
mEq/L.
,●● What is the role of bicarbonate in acid-base balance?
Answer: It is the base component regulated by the kidneys, with a same-
direction relationship with pH.
●● What is the function of the sinoatrial (SA) node?
Answer: It is the heart's natural pacemaker, producing a heart rate of
approximately 60-100 beats per minute.
●● What does the PR interval measure?
Answer: Conduction from the atria through the AV node toward the
ventricles.
●● What does a widened QRS complex indicate?
Answer: Delayed ventricular conduction or an impulse originating
within the ventricles.
●● What does the T wave represent in an ECG?
Answer: Ventricular repolarization.
●● What is the normal duration of the QRS complex?
Answer: Generally less than 0.12 seconds.
, ●● What is the significance of the ST segment in an ECG?
Answer: It represents the period between the end of ventricular
depolarization and the beginning of repolarization.
●● What is the first step in interpreting an ECG?
Answer: Determine whether the rhythm is regular or irregular.
●● What defines normal sinus rhythm?
Answer: A regular rhythm with a heart rate of approximately 60-100
beats per minute and a P wave before every QRS complex.
●● What is sinus bradycardia?
Answer: A heart rate below 60 beats per minute.
●● What is sinus tachycardia?
Answer: A heart rate above 100 beats per minute.
●● What characterizes atrial fibrillation?
Answer: Rapid and chaotic atrial electrical activity with absent P waves
and irregularly irregular R-to-R intervals.
●● What are common causes of atrial fibrillation?
EXAM REVIEW WITH FULL SOLUTIONS
●● What is the normal range for oxygen saturation?
Answer: 95-100%, ideally above 96%.
●● What does PaO2 measure?
Answer: The amount of oxygen dissolved in the plasma.
●● What is the normal range for PaO2?
Answer: Approximately 80-100 mmHg.
●● What indicates severe hypoxemia in terms of PaO2?
Answer: A PaO2 below 40 mmHg.
●● How can expected PaO2 be estimated?
Answer: By multiplying the FiO2 percentage by approximately 5.
●● What is the first step in oxygen delivery for low oxygen levels?
Answer: Supplemental oxygen may be required, starting from a nasal
cannula.
,●● What is the role of carbon dioxide in acid-base balance?
Answer: It combines with water to form carbonic acid, which is
regulated by the lungs and kidneys.
●● What are arterial blood gases (ABGs)?
Answer: They provide important information about pH, carbon dioxide,
bicarbonate, PaO2, and oxygen saturation.
●● What is the normal pH range for blood?
Answer: 7.35-7.45.
●● What happens to pH when CO2 levels increase?
Answer: pH decreases, leading to acidosis.
●● What is respiratory acidosis?
Answer: Occurs when pH is below 7.35 and CO2 is above 45 mmHg.
●● What causes respiratory alkalosis?
Answer: Hyperventilation, anxiety, pregnancy, and strenuous exercise.
●● What is metabolic acidosis?
Answer: Occurs when pH is below 7.35 and bicarbonate is below 22
mEq/L.
,●● What is the role of bicarbonate in acid-base balance?
Answer: It is the base component regulated by the kidneys, with a same-
direction relationship with pH.
●● What is the function of the sinoatrial (SA) node?
Answer: It is the heart's natural pacemaker, producing a heart rate of
approximately 60-100 beats per minute.
●● What does the PR interval measure?
Answer: Conduction from the atria through the AV node toward the
ventricles.
●● What does a widened QRS complex indicate?
Answer: Delayed ventricular conduction or an impulse originating
within the ventricles.
●● What does the T wave represent in an ECG?
Answer: Ventricular repolarization.
●● What is the normal duration of the QRS complex?
Answer: Generally less than 0.12 seconds.
, ●● What is the significance of the ST segment in an ECG?
Answer: It represents the period between the end of ventricular
depolarization and the beginning of repolarization.
●● What is the first step in interpreting an ECG?
Answer: Determine whether the rhythm is regular or irregular.
●● What defines normal sinus rhythm?
Answer: A regular rhythm with a heart rate of approximately 60-100
beats per minute and a P wave before every QRS complex.
●● What is sinus bradycardia?
Answer: A heart rate below 60 beats per minute.
●● What is sinus tachycardia?
Answer: A heart rate above 100 beats per minute.
●● What characterizes atrial fibrillation?
Answer: Rapid and chaotic atrial electrical activity with absent P waves
and irregularly irregular R-to-R intervals.
●● What are common causes of atrial fibrillation?
