Question:easy
A 30 year old male was intubated for surgery. The best method to confirm the position of Endotracheal tube is
A 30 year old male was intubated for surgery. The best method to confirm the position of Endotracheal tube is
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The gold standard for confirming endotracheal tube placement detects a gas that is only present in the airway, not the oesophagus.
Updated On: Jun 23, 2026
- X-ray chest
- Auscultation
- Capnography
- Chest expansion
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The Correct Option is C
Solution and Explanation
Physiological basis of capnography for ET tube confirmation:
When a patient is intubated and ventilated, exhaled gas from the lungs contains $\text{CO}_2$ produced by cellular metabolism. An end-tidal $\text{CO}_2$ (EtCO2) detector measures this $\text{CO}_2$ in expired air.
If the tube is in the trachea: sustained $\text{CO}_2$ waveform detected (typically 35-45 mmHg).
If the tube is in the oesophagus: no sustained $\text{CO}_2$ detected (only a brief transient rise from gastric CO2).
Comparison of methods:
Guidelines recommend continuous waveform capnography as the standard of care for all intubated patients in the OR and ICU.
\[\boxed{\text{Capnography}}\]
When a patient is intubated and ventilated, exhaled gas from the lungs contains $\text{CO}_2$ produced by cellular metabolism. An end-tidal $\text{CO}_2$ (EtCO2) detector measures this $\text{CO}_2$ in expired air.
If the tube is in the trachea: sustained $\text{CO}_2$ waveform detected (typically 35-45 mmHg).
If the tube is in the oesophagus: no sustained $\text{CO}_2$ detected (only a brief transient rise from gastric CO2).
Comparison of methods:
- Auscultation: unreliable alone (transmitted sounds can mimic bilateral air entry)
- Chest X-ray: confirmatory but delayed; not immediate
- Chest expansion: subjective and unreliable
- Capnography: immediate, objective, continuous monitoring -- gold standard
Guidelines recommend continuous waveform capnography as the standard of care for all intubated patients in the OR and ICU.
\[\boxed{\text{Capnography}}\]
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