Case 39: Rising End-Tidal Carbon Dioxide

Abstract

A 6-year-old boy (20 kg) is admitted to hospital with a compound fracture of his right elbow after a fall from a tree. He has had lunch 1 h before admission. His history is otherwise unremarkable. As a 3-year-old, he underwent a tonsillectomy under general anesthesia without any problem. There is no adverse family history of anesthetic complications. On examination, the child is found to be otherwise healthy. Heart rate is 100 beats per minute (bpm). There is a low-grade systolic murmur at the apex. Blood pressure (BP) is 100/60 mmHg, and the chest is clear. The patient is taken to the operating room and all monitors are placed. General anesthesia is induced with propofol, 50 mg, and succinylcholine, 20 mg. Endotracheal intubation is performed with a No. 6 cuffed endotracheal tube (ETT). Breath sounds are equal bilaterally, and gastric breath sounds are not heard. The proximal end of the ETT is attached to a Bain system using the adapter on the Narkomed 2B machine. Anesthesia is maintained with intermittent boluses of fentanyl, vecuronium, and isoflurane 0.5–1.0 %. The fresh gas flow is 6 L (4 L of nitrous oxide and 2 L of oxygen). The lungs are mechanically ventilated using the ventilator on the Narkomed machine. Over a period of 30 min, you observe a gradual increase in end-tidal CO₂ with minimal changes in vital signs. The tympanic and esophageal temperatures record a temperature of 36.1 °C. Bilateral air entry can still be heard, and no abnormal breath sounds are heard. The peak inspiratory pressure reading is 20 cm H₂O and has not changed.