Blood Gas Interpretation in the ICU: A Structured Reading Checklist

A blood gas result is a physiological snapshot. Reading it systematically helps keep sample quality, acid–base balance and the clinical question together. This English educational note develops the blood-gas themes discussed on this platform, with a reference to the American Thoracic Society's teaching resource.

Start with the question and the sample

Before interpreting the numbers, record why the sample was obtained, where it came from and the oxygen or ventilatory support in use. A report without this context can be difficult to compare with a previous result. Keep arterial and venous samples clearly identified in notes and in any calculation tool.

Check the sampling time against the clinical event you are investigating. A measurement taken before a change in support should not be presented as the response to that change. When values look inconsistent, review collection and processing rather than forcing a diagnosis from one number.

Read the acid–base pattern

First assess pH, then consider carbon dioxide and bicarbonate together. A pH within the laboratory reference interval does not exclude a mixed disturbance. In a simple disorder, the accompanying change should fit the expected compensation; an unexpected pattern raises the possibility of another process. Calculate the anion gap and consider albumin when evaluating the metabolic component. These principles are outlined in the ATS guide to ABG interpretation.

Separate description from explanation

A useful written interpretation has two layers. The first describes the laboratory pattern. The second proposes its cause using the patient's history, examination, chemistry results and trend. Keep those layers distinct: a calculation can identify a pattern, but it cannot supply a missing history or confirm the cause by itself.

Document assumptions and units. If the calculation depends on a sample type, a laboratory reference range or an estimated value, say so. That makes the interpretation easier for the next clinician to check and for learners to understand.

A practical documentation checklist

• Clinical question, sample site and collection time.
• Oxygen and ventilatory support at sampling.
• Acid–base pattern and the compensation assessment.
• Electrolytes, albumin and relevant parallel results.
• Comparison with previous samples and remaining uncertainty.

For a description of this platform's calculation workflow, see the blood gas and acid–base tool overview. Its access conditions and limitations are stated there. This checklist is educational and does not prescribe treatment or replace bedside assessment.

Source and further reading

Serdar Efe's Turkish blood-gas tool announcement; David A. Kaufman, Interpretation of Arterial Blood Gases, American Thoracic Society. This page is an English educational companion, not a verbatim translation.

Continue reading

• Anion Gap and Albumin: Why a Normal Gap Can Be Misleading
• Respiratory Pyramid Interface: Understanding the RPI Research and Its Limits

Author: Serdar Efe, MD · Bursa Uludağ University, Türkiye. Publications.

Published: 9 October 2026. English text prepared with AI assistance from the cited platform resources and references.

English: ICU Quality Insights · All English articles