Direct laryngoscopy after potential difficult intubation in children only predicts standard Cormack and Lehane view to within one grade

BACKGROUND: Some techniques used to achieve intubation in children predicted to have a difficult airway do not involve direct laryngoscopy or assessment of the laryngeal grade. Direct laryngoscopy may therefore be performed immediately after intubation to provide a record for future anesthetics. It is unknown whether this postintubation grade accurately reflects the standard laryngeal grade in this group. AIM: The aim of the study was to identify those children who were predicted to be a difficult intubation and to perform direct laryngoscopy before and after intubation. We set out to ascertain if direct laryngoscopy performed after intubation could accurately predict the standard un-intubated laryngeal grade in this group. METHODS: All children presenting for general anesthesia who were clinically predicted to be a difficult intubation were considered for this study and prospectively recruited. After induction of anesthesia, one study anesthetist performed direct laryngoscopy before and another study anesthetist then performed direct laryngoscopy after intubation. These laryngeal grades were then compared. RESULTS: A total of 21 children were successfully recruited and studied, and all patients were successfully intubated. Overall, the postintubation grade did not reliably reflect the standard grade, but did not differ by more than one grade in any patient. In one-third of subjects, the postintubation grade was equal to the standard grade, in one-third it was a grade 'easier' and in one-third a grade 'harder'. CONCLUSION: Assessment and documentation of a postintubation laryngeal grade does not appear to provide reliable information for future anesthetics and may even have the potential to be misleading. Any such documentation should always refer to the presence of an endotracheal tube and be interpreted with caution.