Incidence of cannot intubate-cannot ventilate (CICV): results of a 3-year retrospective multicenter clinical study in a network of university hospitals

The purpose of this study was to investigate the incidence of cannot intubate-cannot ventilate (CICV) during general anesthesia during a 3-year period in a network of university hospitals and to evaluate the events related to it. A retrospective multicenter questionnaire survey of CICV, based on medical record review, was conducted over a 3-year period (January 2010-December 2012) in Hokkaido, Japan. All cases were assessed in terms of the suspected risk factors of CICV, the clinical course during anesthesia, and the prognosis. Responses were obtained from 20 of 21 institutions (95 %) surveyed. The incidence of CICV was 3 of 97,854 cases conducted under general anesthesia (0.003 %). All incidents occurred during induction of general anesthesia. In two of the three cases, difficult airway was predicted preoperatively. In all these three cases, mask ventilation became impossible after repeated intubation attempts with devices such as the Macintosh laryngoscope, the Airwayscope, or a fiberoptic bronchoscope. A laryngeal mask was inserted in one case, but the lungs could not be adequately ventilated. Emergency tracheotomy was eventually performed in all the CICV cases. Although two of the patients did not have postoperative neurological sequelae, severe and permanent brain damage occurred in one patient. In our survey, we found that the incidence of CICV during a 3-year period (2010-2012) was 0.003 % or 1 in 32,000 cases. The three CICV situations occurred after repeated intubation attempts with multiple devices. The appropriate airway devices to be used in a particular difficult airway situation should be carefully considered before performing multiple attempts.