The Thai Anesthesia Incidents Study (THAI Study) of Difficult Intubation : A Qualitative Analysis
Thavat Chanchayanon MD*, Suwannee Suraseranivongse MD**, Waraporn Chau-in MD***
Affiliation : *Songklanagarind Hospital,Faculty of Medicine, Prince of Songkla University, Songkhla, **Siriraj Hospital, Faculty of Medicine, Mahidol University, Bangkok , ***Srinakarind Hospital, Khon Kaen University, Khon Kaen,Thailand
Objectives : To examine the causes, outcomes and contributing factors including suggested corrective strate-
gies associated with difficult intubation
Materials and Methods : 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
Results : 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 inad-
equate preoperative evaluation and preparation. Additional training, quality assurance and protocol/ algo-
rithm tended to minimize the incidents.
Conclusion : 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.
Keywords : Difficult intubation, Failed intubation, Anesthesia, Complications, Adverse events
