Exam 12 - Acid-Base Balance and Bicarbonate Regulation

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Questions and Answers

What is the primary cause of respiratory alkalosis?

COPD

Barbiturate overdose

Airway obstruction

Hyperventilation (correct)

Which of the following symptoms is NOT associated with respiratory alkalosis?

Tachycardia

Dizziness

Confusion

Lethargy (correct)

What treatment approach may aid in reducing respiratory alkalosis caused by anxiety?

Antibiotic therapy

Breathing into a paper bag (correct)

Increased oxygen intake

Sedation

In the context of severe respiratory acidosis where the patient is decompensating quickly, which of the following is a potential treatment option?

Intubation and mechanical ventilation Signup and view all the answers

How do kidneys typically respond to elevated pH levels in respiratory alkalosis?

Conserving hydrogen ions Signup and view all the answers

What is the primary role of bicarbonate (HCO3−) in the body?

To maintain acid-base balance Signup and view all the answers

What is the normal range for bicarbonate levels in the body?

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

Which ratio of carbonic acid to bicarbonate is needed for homeostasis?

1 part carbonic acid to 20 parts bicarbonate Signup and view all the answers

What condition is indicated by a pH level lower than 7.35?

Acidosis Signup and view all the answers

What causes a bicarbonate imbalance leading to metabolic acidosis or alkalosis?

Increases or decreases in hydrogen ions Signup and view all the answers

Which statement about pH levels is correct?

A pH above 7.45 indicates alkalinity Signup and view all the answers

What happens to the pH level as the concentration of hydrogen ions decreases?

The pH level increases, leading to alkalinity Signup and view all the answers

What is the primary role of blood buffers in the body?

To neutralize excess acids or bases by exchanging hydrogen ions. Signup and view all the answers

Which statement about the respiratory system is accurate regarding its role in pH balance?

It adjusts acid-base balance primarily by controlling carbon dioxide levels. Signup and view all the answers

What occurs during acidosis in terms of kidney function?

The kidneys excrete hydrogen ions and retain bicarbonate. Signup and view all the answers

Which type of acid-base imbalance results from impaired ventilation (bradypnea/COPD) and retained carbon dioxide?

Respiratory acidosis Signup and view all the answers

What is the time frame in which the respiratory system can adjust pH in response to an imbalance?

Within minutes Signup and view all the answers

Which organ systems are primarily responsible for the regulation of acid-base balance in the body?

Lungs and kidneys Signup and view all the answers

What triggers the respiratory system to adjust breathing in response to pH changes?

Chemoreceptors in the medulla of the brainstem Signup and view all the answers

What is the most critical action to take if a patient reports feeling 'not right' during a blood transfusion?

Stop the infusion and run normal saline Signup and view all the answers

Which symptom is likely to indicate a transfusion reaction? (Select all that apply)

Chills Signup and view all the answers

In which time frame should the transfusion reaction be observed most critically?

Within the first 15 minutes Signup and view all the answers

What is not a prerequisite for initiating a blood transfusion?

Complete blood count results Signup and view all the answers

What is the recommended time frame for completing a blood transfusion?

2-4 hours Signup and view all the answers

Study Notes

Bicarbonate

Bicarbonate is an alkaline electrolyte that helps regulate pH in the extracellular fluid.
Normal levels are 22 to 24 mEq/L.
The kidneys regulate bicarbonate levels based on need.

Acid-Base Balance

Refers to the balance of hydrogen ions (H+) in body fluids.
High hydrogen ions indicate acidity, while low levels indicate alkalinity.
Hydrogen ion concentration is determined by the ratio of carbonic acid (H2CO3) to bicarbonate (HCO3-) in the extracellular fluid.
The normal ratio is 1 part carbonic acid to 20 parts bicarbonate.
pH measures hydrogen ion concentration in the body.
Normal arterial blood pH is 7.45, venous blood and interstitial fluid is 7.35
A pH below 7.35 is acidic, above 7.45 is alkaline.
pH between 6.8 to 7.8 is usually fatal.
Bicarbonate imbalance leads to metabolic acidosis or alkalosis.
Carbonic acid imbalance leads to respiratory acidosis or alkalosis.

Blood Buffers

Blood buffers are weak acid/base salts or weak base/acid salts.
Examples include bicarbonate/carbonic acid, intracellular proteins, and phosphate in bones.
The bicarbonate system is most important, buffering blood and interstitial fluid.
Buffers work as "chemical sponges" neutralizing excess acids or bases by exchanging hydrogen ions.

Respiratory System

The lungs act as the second line of defense in maintaining pH.
By adjusting breathing rate, the lungs regulate carbon dioxide levels in the blood.
Increased respirations decrease carbon dioxide, lowering carbonic acid and raising pH.
Decreased respirations retain carbon dioxide, increasing carbonic acid and lowering pH.
This system is slower than blood buffers (1 to 2 minutes) but efficient at removing large amounts of acid.

Kidneys

The kidneys are the third line of defense, regulating pH by excreting or retaining acids and bases.
In acidosis, the kidneys excrete hydrogen and retain bicarbonate.
In alkalosis, the kidneys excrete bicarbonate and retain hydrogen.
Normal urine is acidic due to constant elimination of metabolic acids.
The kidneys are the slowest system (hours or days) but essential for precise pH regulation.

Types of Acid-Base Imbalances

Four primary imbalances occur when regulatory systems fail:
- Respiratory acidosis: Low pH due to CO2 retention.
- Respiratory alkalosis: High pH due to CO2 loss.
- Metabolic acidosis: Low pH due to excess acid or bicarbonate loss.
- Metabolic alkalosis: High pH due to bicarbonate gain or acid loss.

Respiratory Acidosis

Caused by impaired ventilation, leading to CO2 retention and increased carbonic acid.
Symptoms: lethargy, confusion, increased heart rate, palpitations, dizziness.
Kidneys attempt to compensate by retaining bicarbonate and eliminating hydrogen.
Treatment focuses on improving ventilation, treating underlying cause, and providing respiratory support.

Respiratory Alkalosis

Most commonly caused by hyperventilation due to anxiety, respiratory distress, or other conditions.
Increased breathing rate or depth leads to excess CO2 loss and decreased carbonic acid.
Symptoms: lightheadedness, numbness, tingling, tinnitus, blurred vision, increased heart rate, irritability.
Treatment aims at addressing the underlying cause and can include breathing exercises, paper bag breathing, or sedation.

Blood Transfusion Reactions

Can be life threatening
Patient may experience sudden discomfort and a sense of impending doom
Signs and symptoms include chills, fever, low back pain, itching, and low blood pressure (hypotension)
Immediately stop the blood transfusion and initiate normal saline intravenous fluid
Delayed reactions are also possible

Initiating Blood Transfusions

Crossmatching is required before transfusion
Informed consent must be obtained from the patient
Monitor the patient closely for transfusion reactions during the first 15 minutes of the transfusion
Infuse the blood product within 2-4 hours of initiation
Use 0.9% normal saline as the primary intravenous fluid when administering blood products
Use a Y-tubing setup for blood transfusions

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Description

This quiz covers the essential concepts of bicarbonate's role in acid-base balance, including normal levels, regulation by the kidneys, and the implications of pH levels in body fluids. It also examines blood buffers and their importance in maintaining homeostasis. Test your knowledge on these critical physiological aspects!