Most modern anesthesia workstations provide automated checkout, which indicates the readiness of the anesthesia machine. In this case report, an anesthesia machine passed the automated machine checkout. Minutes after the induction of general anesthesia, we observed a mismatch between the selected and delivered tidal volumes in the volume auto flow mode with increased inspiratory resistance during manual ventilation. Endotracheal tube kinking, circuit obstruction, leaks, and patient-related factors were ruled out. Further investigation revealed a broken internal insert within the CO2 absorbent canister that allowed absorbent granules to cause a partial obstruction to inspiratory and expiratory flow triggering contradictory alarms. We concluded that even when the automated machine checkout indicates machine readiness, unforeseen equipment failure due to unexpected events can occur and require providers to remain vigilant.
From the Department of Anesthesiology & Perioperative Medicine, Tufts Medical Center, Boston, Massachusetts.
Accepted for publication October 21, 2016.
Funding: This study was supported by Department of Anesthesiology, Tufts Medical Center.
The authors declare no conflicts of interest.
Address correspondence to Roman Schumann, MD, Department of Anesthesiology & Perioperative Medicine, Tufts Medical Center, 800 Washington St, Box# 298, Boston, MA 02148. Address e-mail to RSchumann@tuftsmedicalcenter.org.