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Insufficient evidence to make a recommendation.

Strongly favor this test or intervention.

The Arterial Blood Gas Interpreter analyzes three key parameters: arterial pH, partial pressure of carbon dioxide (PaCO₂), and bicarbonate (HCO₃⁻) levels to assess acid-base balance in the body. Here’s how it works:

1. **Input Parameters**
   - Arterial pH: Measures the acidity or alkalinity of the blood. A normal range is between 7.35 and 7.45.
   - PaCO₂: The pressure exerted by carbon dioxide in the blood, typically between 35-45 mmHg. If measured in kPa, it is converted to mmHg by multiplying by 7.5.
   - HCO₃⁻: The concentration of bicarbonate in the blood, with a normal level around 24 mmol/L.

2. **Determine Acid-Base Status**
   - If pH is normal (7.35-7.45), the status is "Normal."
   - If pH is less than 7.35, "Acidosis" is indicated; specific classification depends on PaCO₂ level:
     - If PaCO₂ > 45, it suggests "Respiratory Acidosis."
     - If PaCO₂ <= 45, it suggests "Metabolic Acidosis."
   - If pH is greater than 7.45, "Alkalosis" is indicated; specific classification depends on PaCO₂ level:
     - If PaCO₂ < 35, it suggests "Respiratory Alkalosis."
     - If PaCO₂ >= 35, it suggests "Metabolic Alkalosis."

3. **Calculate Expected Values for Compensation**
   - For "Respiratory Acidosis," expected HCO₃⁻ is 24 + (PaCO₂ - 40) / 10.
   - For "Respiratory Alkalosis," expected HCO₃⁻ is 24 - (40 - PaCO₂) / 5.
   - For "Metabolic Acidosis," expected PaCO₂ is 40 - (24 - HCO₃⁻) * 1.2.
   - For "Metabolic Alkalosis," expected PaCO₂ is 40 + (HCO₃⁻ - 24) * 0.7.

4. **Determine Compensation Level**
   - "Uncompensated" indicates no significant correctional changes.
   - "Partially Compensated" is considered if deviation from expected values is moderate (≤ 5 units).
   - "Fully Compensated" is concluded with minimal deviation (≤ 2 units) from expected values.

5. **Interpretation and Breakdown**
   - The analysis concludes with indicating if there’s an acidosis or alkalosis, its type, and compensation level.
   - Interpretation provides insights, suggesting chronic conditions if compensation is partial or full.
   - A breakdown of calculations includes expected vs. actual values for HCO₃⁻ and PaCO₂.

This interpretation aids healthcare providers in understanding whether the body’s compensatory mechanisms are effectively mitigating the imbalance, helping diagnose underlying conditions like respiratory or metabolic dysfunctions.

The Arterial Blood Gas (ABG) Interpreter analyzes arterial blood gas results, including pH, PaCO₂, and HCO₃⁻, to assess acid-base status, oxygenation, and ventilation. It aids in diagnosing respiratory, metabolic, and mixed acid-base disorders, guiding clinical management in acute and chronic conditions.

Blood gas analysis

Background

Overview

Guidelines

Key sources

Diagnostic investigations