Breathing circuit obstruction: An unusual case.

Sir,

Errors in medical practice are not an uncommon occurrence. These can be either due to the machine failure or human failure.[1] Such errors can be catastrophic, if timely appropriate corrective steps not instituted. Nowadays, the newer anesthesia work-stations are equipped with sensors to monitor the spiromtory functions of anesthetized patients. These sensors are attached on the patient's end of the ventilator tubings, proximal to the patient's airway. We report a case of respiratory obstruction due to the presence of an unusual foreign body on the reusable D-lite™ spirometer sensor of the Datex Omeda monitor.

Following induction of anesthesia, the airway of the patient was secured with 8.5 mm ID cuffed endotracheal tube. On connecting the ventilator circuit, it was observed that the patient's chest was not moving. There were no breath sounds on auscultation. The peak pressures rose to 40-42 cm of H2O and the arterial oxygen saturation of the patient dropped to 85%. The ventilator circuit was immediately replaced with the Bains coaxial circuit and the Fio2 increased to 100%. The patient could then be ventilated easily. There was increased in the arterial saturation and the peak pressures dropped to the normal limits. The rest of the surgery went uneventful.

On closer inspection of the ventilator circuit, it was detected that a piece of the plastic wrapping of the D-lite sensor was left in between the sensor and the ventilator circuit which was causing the obstruction [Figure 1]. This small piece of wrapping was not visible from outside, which led to this mishap [Figure 2].

Figure 1

Plastic wrapping causing breathing circuit obstruction

Figure 2

Plastic wrapping unnoticed from outside

Earlier, obstructions in the ventilator circuit due to blocked heat and moisture exchanging filters (HMEF), faulty equipment or unusual foreign bodies like plastic wrappings have been reported leading to anesthetic mishaps.[234] Such obstructions in the ventilator circuit can mimic a condition of pnemothorax, silent chest, or severe bronchospasm.[5] Reporting of such critical events, re-emphasizes the need to check all the parts of anesthesia equipment before use to prevent the occurrence of these anesthetic mishaps in future.