A Novel Leak from an Unfamiliar Component

Abstract

To the Editor: New anesthesia machines may contain unfamiliar components, which may be difficult to troubleshoot (1). We report four cases of a novel type of leak in the Drager Fabius GS. Case 1. Preoperative checkout of the anesthesia machine, including the automated leak/compliance test, was performed and no defect was found. After endotracheal intubation, it was impossible to ventilate because of a large leak from a broken flow sensor. Case 2. During service between cases, an anesthesia technician bumped the absorbent canister into the sensor's electrical connector and fractured it, unbeknownst to the anesthesia team. Cases 3 and 4. An unexplained leak during ventilation after induction of general anesthesia was traced to a broken sensor. The mechanism of injury was not identified. The flow sensor consists of a plastic tube with a side port containing electronic components. A cable runs from the side port to the back of the machine (Fig. 1). Apparently, in case 1, the patient'sstretcher bumped an IV pole against the electrical connector and the sensor's side port was dislodged (Fig. 2).Figure 1.: View of the underside of the “Compact Breathing System.” The arrow indicates the position of the Flow Sensor.Figure 2.: The Flow Sensor and its electrical connector. The arrow indicates the site of the leak, an inappropriate dislodgement of the side port from the body of the sensor.The flow sensor's rigid electrical connector hangs near the exterior edge of the “Compact Breathing System.” Damage can occur when lateral force on the connector exerts torque upon the sensor's side arm. Personnel using the Fabius GS should be aware of this potential hazard and protect this vulnerable connection. The authors recommend performing a quick leak test by manually occluding the end of the circuit with the APL valve closed immediately before every induction, as this would have identified the defect in all of these cases. Drager Medical and the United States Food and Drug Administration have been contacted, and our department was informed that redesign is under consideration. Stephen O. Bader, MD Kirti K. Doshi, MD Zvi Grunwald, MD Department of Anesthesiology Thomas Jefferson University Hospital Philadelphia, PA [email protected]