An international RAND/UCLA expert panel to determine the optimal diagnosis and management of burn inhalation injury

Abstract

Background: Burn inhalation injury (BII) is a major cause of burn-related mortality and morbidity. Despite published practice guidelines, no consensus exists for the best strategies regarding diagnosis and management of BII. A modified DELPHI study using the RAND/UCLA (University of California, Los Angeles) Appropriateness Method (RAM) systematically analysed the opinions of an expert panel. Expert opinion was combined with available evidence to determine what constitutes appropriate and inappropriate judgement in the diagnosis and management of BII.

Methods: A 15-person multidisciplinary panel comprised anaesthetists, intensivists and plastic surgeons involved in the clinical management of major burn patients adopted a modified Delphi approach using the RAM method. They rated the appropriateness of statements describing diagnostic and management options for BII on a Likert scale. A modified final survey comprising 140 statements was completed, subdivided into history and physical examination (20), investigations (39), airway management (5), systemic toxicity (23), invasive mechanical ventilation (29) and pharmacotherapy (24). Median appropriateness ratings and the disagreement index (DI) were calculated to classify statements as appropriate, uncertain, or inappropriate.

Results: Of 140 statements, 74 were rated as appropriate, 40 as uncertain and 26 as inappropriate. Initial intubation with ≥ 8.0 mm endotracheal tubes, lung protective ventilatory strategies, initial bronchoscopic lavage, serial bronchoscopic lavage for severe BII, nebulised heparin and salbutamol administration for moderate-severe BII and N-acetylcysteine for moderate BII were rated appropriate. Non-protective ventilatory strategies, high-frequency oscillatory ventilation, high-frequency percussive ventilation, prophylactic systemic antibiotics and corticosteroids were rated inappropriate. Experts disagreed (DI ≥ 1) on six statements, classified uncertain: the use of flexible fiberoptic bronchoscopy to guide fluid requirements (DI = 1.52), intubation with endotracheal tubes of internal diameter < 8.0 mm (DI = 1.19), use of airway pressure release ventilation modality (DI = 1.19) and nebulised 5000IU heparin, N-acetylcysteine and salbutamol for mild BII (DI = 1.52, 1.70, 1.36, respectively).

Conclusions: Burns experts mostly agreed on appropriate and inappropriate diagnostic and management criteria of BII as in published guidance. Uncertainty exists as to the optimal diagnosis and management of differing grades of severity of BII. Future research should investigate the accuracy of bronchoscopic grading of BII, the value of bronchial lavage in differing severity groups and the effectiveness of nebulised therapies in different severities of BII.

Keywords: Acute lung injury; Acute respiratory distress syndrome; Bronchoscopy; Burn inhalation injury; Burns; Endotracheal intubation; Heparin; Mechanical ventilation; Smoke inhalation injury.

Fig. 1

Current International Society for Burn Injuries (ISBI) practice guidelines for burn inhalation injury [9]

Fig. 2

Appropriateness of using history and examination findings as indicators of potential burn inhalation injury. For each statement, median scores were calculated. Statements with a median score of ≤ 3 being classed inappropriate (red background), > 3 and < 7 uncertain (amber background) and ≥ 7 appropriate (green background). Disagreement was not present for any statements. Panellists n = 15

Fig. 3

Appropriateness of investigations in the diagnosis and management of burn inhalation injury. For each statement, median scores were calculated. Statements with a median score of ≤ 3 being classed inappropriate (red background), > 3 and < 7 uncertain (amber background) and ≥ 7 appropriate (green background). Burn inhalation injury severity was defined according to Abbreviated Injury Score criteria as mild (grade 1), moderate (grade 2) and severe (grades 3–4). Disagreement was present for one statement (DI ≥ 1). BII, burn inhalation injury. Panellists n = 15. *Fiberoptic bronchoscopy, if intubated. ‡Denotes disagreement (DI ≥ 1)

Fig. 4

Appropriateness of airway management strategies for burn inhalation injury. For each statement, median scores were calculated. Statements with median score of < 3.5 were classed as inappropriate (red background), ≥ 3.5 and < 6.5 as uncertain (amber background) and ≥ 6.5 as appropriate (green background). Disagreement was present for one statement (DI ≥ 1). BII = burn inhalation injury. Panellists n = 10. *Exceeding 7 days. ‡Denotes disagreement (DI ≥ 1). §In-between theatre visits

Fig. 5

Appropriateness of diagnostic and management strategies for burn inhalation injury associated systemic toxicity. For each statement, median scores were calculated. Statements with a median score of ≤ 3 being classed inappropriate (red background), > 3 and < 7 uncertain (amber background) and ≥ 7 appropriate (green background). Clinical suspicion of hydrogen cyanide toxicity was defined as low (normal blood lactate and the absence of potentially suspicious features), moderate (moderate lactatemia below 8 mmol/L and few potentially suspicious features) and high (hyperlactataemia ≥ 8 mmol/L and potentially suspicious features including anion gap lactic metabolic acidosis, altered consciousness, unexplained cardiac dysfunction). High serum lactate was defined as ≥ 8 mmol/L. Disagreement was not present for any statements. BII, burn inhalation injury. Panellists n = 15. *Until a higher clinical suspicion or laboratory confirmation is available

Fig. 6

Appropriateness of ventilation strategies for burn inhalation injury and/or acute respiratory distress syndrome. For each statement, median scores were calculated. Statements with median score of < 3.5 were classed as inappropriate (red background), ≥ 3.5 and < 6.5 as uncertain (amber background) and ≥ 6.5 as appropriate (green background). Lung protective ventilatory strategies were defined as tidal volume < 6 mL/kg ideal body weight, plateau pressure < 30 cmH₂0. Disagreement was present for one statement (DI ≥ 1). BII, burn inhalation injury. ARDS, acute respiratory distress syndrome. Panellists n = 10. ‡Denotes disagreement (DI ≥ 1)

Fig. 7

Appropriateness of pharmacological therapies for varying severities of burn inhalation injury. For each statement, median scores were calculated. Statements with a median score of ≤ 3 being classed inappropriate (red background), > 3 and < 7 uncertain (amber background) and ≥ 7 appropriate (green background). Burn inhalation injury severity was defined according to Abbreviated Injury Score criteria as mild (grade 1), moderate (grade 2) and severe (grades 3–4). Disagreement was present for three statements (DI ≥ 1). BII, burn inhalation injury. IU, international units. Panellists n = 15. ‡Denotes disagreement (DI ≥ 1)

Fig. 8

Summary of expert panel recommendations for burn inhalation injury. Parts of the figure were drawn by using pictures from Servier Medical Art. Servier Medical Art by Servier is licensed under a Creative Commons Attribution 3.0 Unported License (https://creativecommons.org/licenses/by/3.0/)