Despite a wealth of peer-reviewed publications on this topic, aspects of smoke inhalation injury (SII) remain elusive [1]. There are two fundamental issues limiting our progress. First, there are no recognised diagnostic criteria. Second, there has been inadequate description of upper airway changes in SII. The aims of this study were to 1) introduce a modified tool to assess upper airway changes in SII, 2) assess its usefulness as a prognostic factor, and 3) to identify clinical variables showing strong correlations with severe injury.
A retrospective study of consecutive patients with SII was conducted at Fiona Stanley Hospital, Western Australia, over a ten-year period. A modified grading system for upper airway assessment of SII, the SInhale Classification System, was prospectively developed and retrospectively applied.
Class III injury (lower airway SII) was found to be significantly associated with greater than 24h of intubation, increased mean duration of mechanical ventilation, increased frequency of prolonged intubation, increased requirement for tracheostomy, and increased mean Intensive Care and inpatient lengths of stays, compared with Class I injury (mild upper airway SII). Class II injury (severe upper airway SII, including stenosing laryngeal oedema) was significantly associated with increased numbers of failed extubation. Full thickness head and neck burn and soot in the oral cavity/oropharynx/nasopharynx were the only statistically significant clinical variables correlated with severe (Class II and III) injuries.
SInhale appears to be a useful tool for the standardisation of upper airway assessment in SII. External and prospective studies are required to validate our findings.