Failure to ventilate: Technical error.

Sir,

A 22-year-old girl having history of brochial asthma with normal preanesthetic check-up and normal airway examination was posted for surgery for bilateral fibroadenama breast under general anesthesia. On the day of surgery, she was premedicated with fentanyl 50 μg and midazolam 2 mg 30 minutes before operation. In the operation theatre monitoring was started as per the American Society of Anaesthesiologist (ASA) standard. A venous cannula was inserted and was given 100% oxygen. After giving propofol 100 mg, she went into apnea immediately; we tried to ventilate the patient with bag and mask. While mask ventilation we found that the bag was too tight and the patient was not at all ventilating. Despite all efforts, it was not possible to ventilate the patient. Her saturation started dropping, immediately we intubated the patient and connected the anesthesia ventilator. Now the patient was nicely ventilating with peak airway pressure of 18 cm of H2O. On auscultation the chest was clear, no rhochi or spasm was detected and saturation rose to 100%. While investigating the cause of airway obstruction, we checked the circuit which was found to be absolutely obstruction free. While checking the mask, to our surprise we found that the cap of the ventilator circuit was fitting to the mask [Figure 1]. While investigating about the technical check-up before assembling the circuit, we found that the technician who had assembled the circuit, forgot to remove the cap from the ventilator circuit [Figure 2].

Figure 1

Cap fitting to the mask

Figure 2

Cap obstructing the circuit

There are numerous reports of obstruction of anesthesia breathing circuits by different foreign bodies and due to technical errors.[1-3] Most of these instances are due to inadequate check-up of the equipments. In our case the technician checked and assembled the circuit. Before induction of anesthesia, we checked the circuit for any leakage and obstruction by removing the mask, we found that the circuit was obstruction free as the cap, which was tightly fitting to the mask, also got removed with the mask. However, we did not check the mask. While again reassembling the circuit due to cap in the mask it caused total obstruction of the circuit leading to impossible ventilation. When, after intubation, we removed the mask from the circuit the cap remained in the mask and problem remained unnoticed. While thoroughly checking the equipments we finally found the obstructing cap fitting to the mask.

Here, we emphasize on sticking to the basics and thoroughly follow the preuse check guidelines to prevent critical incidents and improve patient safety.[45] The nontechnical staff of the operation theatre should be educated and trained about correct assembling and preuse checks and lastly the anesthetist should check and confirm the proper working of the equipments before anesthetizing the cases.