The Thai Anesthesia Incidents Study (THAI Study) of difficult intubation: a qualitative analysis

To examine the causes, outcomes and contributing factors including suggested corrective strategies associated with difficult intubation.

Difficult intubation and failed intubation incidents were extracted from the Thai Anesthesia Incidents Study (THAI Study) database conducted between February 1, 2003 to January 31, 2004 and analyzed by using descriptive statistics

Two hundred and thirty-four cases of difficult intubation were recorded. Among those, 50 cases (21%) were failed intubation. The most common cause (95%) of incidents was due to patients difficult anatomy. Prediction of events was derived from physical examination (65%) and history taking (50%). Majority of incidents (44%) occurred in Mallampati II and III. Only 3 cases (1.3%) of morbid obesed and 3 cases (1.3%) of pregnant patients were attributed to the events. Most incidents (119 cases, 50.9%) were successfully managed by conventional techniques. The adverse effects included hypoxemia (54 cases, 23.1%), esophageal/ tracheal injury (40 cases, 17.1%) and prolonged ventilatory support (17 cases, 7.3%). One patient died from sepsis. The reported contributing factors included inadequate experience, lack of knowledge including inadequate preoperative evaluation and preparation. Additional training, quality assurance and protocol/algorithm tended to minimize the incidents.

The majority of difficult intubation could be predicted. Proper preoperative evaluation and equipment preparation, appropriate technique including experienced anesthesia personnel could attenuate the morbidity and mortality.