Ans. a. Capnography Capnography is the surest confirmatory sign of correct intubationQ So, the fastest and accurate method to confirm intubation in the above mentioned infant is capnography Capnography Capnography is the continuous measurement of end tidal carbon dioxide (ETCO,) and its waveform. Normal: 32 to 42 mmHe (3 to 4 mmHg less than aerial pCO, which is 35 to 45 mmHg) Principle: Infrared light is absorbed by carbon dioxide Uses of Capnography It is the surest confirmatory sign of correct intubation (esophageal intubation will yield ETCO2=0) Intraoperative displacement of endotracheal tubedeg (ETCO2 will become zero) Diagnosis of malignant hypehermie (ETCO, may rise to more than 100 mm Hg) For detecting obstructions and disconnections of endotracheal tubes (ETCO, will fall) Capnography Uses of Capnography Diagnosing pulmonary embolism by air, fat or thrombus (sudden fall of ETCO2 occurs. It may become zero if embolus is large enough to block total pulmonary circulation) Exhausted sodalime or defective valves of closed circuit will show high ETCO2 values. To control level of hypocapnia during hyperventilation in neurosurgery Indicator of cardiac output. In cardiac arrest ETCO, is zero.