Biochemistry Buffers and Blood Gas Analysis

Questions and Answers

Which condition is NOT a direct cause of metabolic acidosis?

Diabetic ketoacidosis

Starvation

Renal failure

Hyperventilation (correct)

When calculating the anion gap, which ions are used in the formula?

Na+ and Cl

Na+ and HCO3 + Cl (correct)

Cl and Ca2+

Na+ and HCO3

What is a possible consequence of hyperventilation in metabolic acidosis?

Compensatory increase in respiratory rate (correct)

High plasma chloride levels

Increase in plasma pCO2

Decrease in bicarbonate concentration

Which of the following is NOT a cause of metabolic alkalosis?

Increased metabolic rate Signup and view all the answers

Which condition can lead to fluid losses below the gastric sphincter and contribute to acidosis?

Diarrhea Signup and view all the answers

What is a common cause of excessive CO2 retention leading to partially compensated acidosis?

Airway obstruction Signup and view all the answers

In a case of fully compensated metabolic acidosis, what would be a likely change in arterial blood gas values?

Normal pH with elevated pCO2 Signup and view all the answers

What type of respiratory condition is characterized by a pH of 7.34, pCO2 of 59, and HCO3 of 28?

Partially compensated respiratory acidosis Signup and view all the answers

What effect does the addition of acid or base have on a buffered solution as long as the components are not depleted?

Barely affects the pH Signup and view all the answers

What factor is least likely to lead to decreased lung surface area participating in gas exchange?

Hypertension Signup and view all the answers

Which of the following could indicate respiratory alkalosis due to hyperventilation?

Elevated pH and low pCO2 Signup and view all the answers

In the context of arterial blood gas analysis, what does pCO2 primarily indicate?

The partial pressure of carbon dioxide in the blood Signup and view all the answers

Which of the following pH values falls within the normal range for blood?

7.35 Signup and view all the answers

What is the normal range for bicarbonate (HCO3) levels in the blood?

22-26 mEq/L Signup and view all the answers

Which of the following conditions can be identified through blood gas analysis?

Acid-base balance abnormalities Signup and view all the answers

Which component is NOT typically involved in acid-base regulation?

Oxygen saturation Signup and view all the answers

What defines a fully compensated acid-base status?

pH returns to normal range despite respiratory disturbance Signup and view all the answers

What is the main focus of the Anion Gap calculation in metabolic conditions?

To identify unmeasured anions in the blood Signup and view all the answers

What is the primary way to eliminate non-volatile acids from the body?

Excrete hydrogen ions in urine Signup and view all the answers

Which of the following statements is true regarding bicarbonate reabsorption in the kidneys?

Bicarbonate produced from carbonic acid contributes to alkalinity Signup and view all the answers

What occurs during respiratory acidosis?

The blood pH decreases due to increased CO2 levels Signup and view all the answers

Which acidic condition corresponds with decreased bicarbonate levels?

Metabolic acidosis Signup and view all the answers

Which step of basic ABG interpretation involves evaluating the metabolic status?

Third step Signup and view all the answers

What is the physiological consequence of a rise in hydrogen ion concentration in the blood?

Decreased blood pH leading to respiratory acidosis Signup and view all the answers

What is the hallmark of metabolic alkalosis?

Increased bicarbonate levels Signup and view all the answers

Which component of the acid-base balance is primarily impacted by the kidneys?

Hydrogen ion elimination Signup and view all the answers

What is the primary cause of HCO3 retention in metabolic acidosis?

Loss of extracellular acid through various means Signup and view all the answers

Which condition is likely to cause loss of HCO3 due to gastrointestinal processes?

Vomiting Signup and view all the answers

Which of the following is NOT a typical method of HCO3 loss?

Increased dietary intake of alkaline foods Signup and view all the answers

What compensatory mechanism occurs in response to metabolic acidosis?

Decreased breathing rate to increase pCO2 Signup and view all the answers

Which statement about anion gap in metabolic acidosis is true?

It reflects the difference between total cations and anions Signup and view all the answers

Which type of anion gap is associated with high metabolic acid production?

High anion gap (HAGMA) Signup and view all the answers

What is the typical timeframe for maximal compensation in metabolic acidosis?

12-24 hours Signup and view all the answers

Which of the following is a possible effect of diuretic therapy related to acid-base balance?

Loss of potassium and bicarbonate Signup and view all the answers

Study Notes

Buffers

Buffers resist changes in pH upon the addition of acids or bases, provided that their acidic or basic forms remain intact.

Blood Gas Analysis

Essential for diagnosing acid-base balance, oxygenation status, and respiratory abnormalities.
Components include pH (normal range: 7.35 - 7.45), pCO2 (normal range: 35-45 mmHg), and HCO3 (normal range: 22-26 mEq/L).

Interpretation of Arterial Blood Gas (ABG) Analysis

Steps:
- Evaluate pH to determine acid-base status.
- Assess respiratory status via pCO2 levels.
- Evaluate metabolic status through HCO3 levels.
- Identify which regulatory system is responsible for imbalances.

Acid-Base Compensation

Uncompensated: primary disturbance evident in pH values.
Partially compensated: both respiratory and metabolic factors affect pH.
Fully compensated: normal pH achieved despite underlying disorder due to compensatory mechanisms.

Respiratory Disorders

Respiratory Acidosis: Increased CO2 leads to decreased pH (e.g., airway obstruction, respiratory depression).
Respiratory Alkalosis: Decreased CO2 causes increased pH (e.g., hyperventilation).

Metabolic Disorders

Metabolic Acidosis: Decreased HCO3 leads to decreased pH (e.g., diarrhea, renal failure).
Metabolic Alkalosis: Increased HCO3 causes increased pH (e.g., vomiting, diuretic use).

Anion Gap

Used to determine causes of metabolic acidosis.
Calculated as sodium minus the sum of bicarbonate and chloride (Na+ – (HCO3 + Cl)).
High anion gap indicates potential metabolic acidosis from non-volatile acids; normal anion gap indicates gastrointestinal bicarbonate loss.

Causes of Metabolic Disorders

Metabolic Acidosis: causes include diabetic ketoacidosis, sepsis, and renal failure.
Metabolic Alkalosis: caused by loss of acid via vomiting, diuretics, or alkali ingestion.

Compensation Mechanisms

Respiratory compensation for metabolic acidosis involves increased breathing rate to expel CO2.
In metabolic alkalosis, hypoventilation occurs to retain CO2, attempting to increase acidity back toward normal levels.

Clinical Context

ABG analysis aids in forming comprehensive treatment plans for patients with respiratory and metabolic disturbances, allowing for targeted interventions based on underlying causes and compensation status.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the concepts of buffers, specifically focusing on the Henderson-Hasselbalch Equation, and their role in blood gas analysis. Understanding these topics is essential for analyzing pH levels in physiological conditions. Test your knowledge on how buffers maintain pH stability in biological systems.