p.4
Anion Gap and Differential Diagnosis
What does it indicate if ΔΔ is greater than normal HCO3-?
The presence of additional metabolic alkalosis.
p.1
Compensatory Mechanisms in Acid-Base Disorders
How long does the renal metabolic response take to reach equilibrium?
Typically takes at least three to five days.
p.2
Metabolic Acidosis and Alkalosis
What is a primary metabolic acid-base imbalance caused by?
Changes in bicarbonate excretion by the kidneys.
p.3
Classification of Acid-Base Disturbances
What is the primary disorder associated with metabolic acidosis?
A decrease in bicarbonate (HCO3).
p.4
Clinical Scenarios and Acid-Base Interpretation
What can cause hypercarbia in a post-operative patient?
Sedation from pain, anxiety, and anesthesia medications decreasing respiratory drive.
p.1
Compensatory Mechanisms in Acid-Base Disorders
What is the time frame for respiratory compensation in acid-base balance?
Respiratory compensation occurs within 30 minutes.
p.5
Diagnostic Studies for Acid-Base Imbalances
What is the purpose of arterial blood gas (ABG) analysis?
To measure pH, pCO2, pO2, and base deficit/excess.
p.5
Management of Acid-Base Disturbances
Why should sodium bicarbonate be used cautiously in acidemia?
It has been shown to increase mortality in certain cases.
p.1
Respiratory Acidosis and Alkalosis
What can cause respiratory acidosis in surgical patients?
Decreased minute ventilation due to opioids, anxiolytics, and anesthetics.
p.3
Classification of Acid-Base Disturbances
What suggests the presence of metabolic acidosis or respiratory alkalosis?
Both PCO2 and [HCO3] are low.
p.5
Management of Acid-Base Disturbances
What can be administered in cases of severe metabolic alkalosis?
Intravenous hydrochloric acid.
p.4
Compensatory Mechanisms in Acid-Base Disorders
What is the compensatory change for acute respiratory alkalosis?
Decreased HCO3- by 0.2×∆pCO2.
p.4
Clinical Scenarios and Acid-Base Interpretation
What clinical scenario suggests primary metabolic acidemia?
A critically ill surgical patient with increasing vasopressor requirements and hemodynamic collapse.
p.1
Physiology of Acid-Base Homeostasis
What role does carbonic anhydrase play in the lungs?
It converts carbonic acid to water and CO2.
p.5
Compensatory Mechanisms in Acid-Base Disorders
How can ventilator settings assist in acid-base disturbances?
By providing additional compensation to correct the disturbance.
p.3
Metabolic Acidosis and Alkalosis
What does a base deficit indicate?
Metabolic acidosis or compensation.
p.1
Buffer Systems: Metabolic and Respiratory
What are the two main acid-base buffer systems in the human body?
The metabolic system (kidneys) and the respiratory system (lungs).
p.1
Classification of Acid-Base Disturbances
What are the five primary classifications of acid-base imbalance?
Metabolic acidosis, metabolic alkalosis, respiratory acidosis, respiratory alkalosis, and mixed acid-base disturbance.
p.1
Management of Acid-Base Disturbances
How can mechanical ventilation affect acid-base balance?
It can develop disturbances from inappropriate sedation or ventilator settings.
p.5
Management of Acid-Base Disturbances
What is the most important principle in managing acid-base disturbances?
To treat the cause, not the effect.
p.1
Respiratory Acidosis and Alkalosis
What can lead to respiratory alkalosis in patients?
Increased minute ventilation due to postoperative pain or anxiety.
p.7
Classification of Acid-Base Disturbances
What is the acid-base disorder present in a patient with a pH of 7.54, pCO2 of 49, pO2 of 106, and HCO3 of 36?
Metabolic alkalosis with compensatory respiratory acidosis.
p.2
Anion Gap and Differential Diagnosis
What is the formula to calculate the anion gap?
AG = Na⁺ - (HCO₃⁻ + Cl⁻).
p.1
Physiology of Acid-Base Homeostasis
What is the normal pH range of human blood?
7.35 to 7.45, with a normal average of 7.40.
p.4
Compensatory Mechanisms in Acid-Base Disorders
What compensatory change occurs in chronic respiratory acidosis?
Increased HCO3- by 0.35×∆pCO2.
p.4
Anion Gap and Differential Diagnosis
What does a high anion gap indicate?
The primary disorder is likely to be metabolic acidosis.
p.4
Clinical Scenarios and Acid-Base Interpretation
What is a common sign of primary respiratory acidosis?
Somnolence and/or bradypnea in a post-operative patient.
p.5
Management of Acid-Base Disturbances
What supportive measure can be used for severe acidemia in unstable patients?
Infusion of alkaline medications like sodium bicarbonate.
p.3
Classification of Acid-Base Disturbances
What suggests the presence of metabolic alkalosis or respiratory acidosis?
Both PCO2 and [HCO3] are high.
p.2
Metabolic Acidosis and Alkalosis
What are the common causes of metabolic alkalosis in surgical patients?
Gastrointestinal loss of hydrochloric acid (vomiting) and volume contraction.
p.3
Compensatory Mechanisms in Acid-Base Disorders
What is a key rule regarding compensation in acid-base disorders?
Compensation will rarely restore pH to normal.
p.3
Classification of Acid-Base Disturbances
What indicates a mixed acid-base disturbance?
PCO2 and [HCO3] move in opposite directions.
