Impact of diagnostic bronchoscopy in burned adults with suspected inhalation injury

Evaluating inter-and intra-rater reliability in the bronchoscopic grading of burn inhalation injury: The iBRONCH-BII study

BACKGROUND

The evidence that the severity of burn inhalation injury (BII) impacts clinical outcomes is inconsistent. This may be due to misclassification arising from the subjectivity in bronchoscopically grading BII using systems such as the Abbreviated Injury Score (AIS). This study aimed to evaluate inter- and intra-rater reliability in the grading of BII using the AIS.

METHODOLOGY

In a cohort study, specialist burns clinicians (n = 17) and novices (n = 10) graded sixteen BII bronchoscopic images using the AIS during an online meeting. Inter-rater reliability was evaluated using the Kappa statistic (k), with values < 0.60 considered clinically inadequate. The grade rating process was repeated after seven days to evaluate intra-rater reliability. Evaluation of reliability in the grading of BII bronchoscopy reports was conducted as a sensitivity analysis.

RESULTS

Amongst all raters, inter-rater reliability was low for grading images (k = 0.30, 95 % confidence interval (CI): 0.29-0.31). Intra-rater reliability was higher than inter-rater reliability, but was still low, with median image grade rate k = 0.45 (interquartile range [IQR]:0.24-0.53). Intensivists demonstrated the highest rater reliability.

CONCLUSION

Reliability in rating the grade of BII by bronchoscopic images was clinically inadequate. Strategies to improve the reliability of reporting the grade of BII are required.

Incidence of Pneumonia Following Bronchoscopy and Bronchoalveolar Lavage in Burn Patients

The standard modality for diagnosis of smoke inhalational injury in burn patients is bronchoscopy with or without bronchoalveolar lavage (BAL). However, the risks associated with these procedures are poorly described in established literature. We sought to investigate the association between diagnostic BAL at admission and the development of pneumonia in burn patients. This retrospective analysis of intubated burn patients studied those who underwent bronchoscopy on admission, comparing patients who received BAL to those who did not. Demographics and baseline characteristics were analyzed using chi-squared or Student's t-test. Unadjusted and multivariable logistic regression studies assessed the effect of admission BAL on the development of pneumonia. Out of the 196 patients who underwent bronchoscopy, 98 met our criteria for analysis. The BAL group was more likely to be male and have a higher grade of abbreviated injury score. Patients who received BAL were more likely to develop pneumonia during the admission in both unadjusted and multivariable logistic regression models. These patients also had a longer hospital length of stay, greater number of ventilator days, and were more likely to undergo second bronchoscopy. These findings associate admission BAL with increased risk of pneumonia during the index hospitalization, suggesting a judicious use of BAL during admission bronchoscopy in burn patients.

"To BAL or not to BAL, that is the question": Variations in smoke inhalation injury guidelines from burn units and centres in England, Scotland and Wales

AIM

To evaluate variations in diagnostic criteria and management recommendations for smoke inhalation injury (SII) amongst the burn networks of England, Scotland, and Wales.

METHODS

A descriptive cross-sectional study examining SII guidelines provided by adult burn units and centres in England, Scotland and Wales.

RESULTS

All 16 adult burn units and centres responded. Fourteen (87.5 %) had guidelines. Due to sharing of guidelines, ten unique guidelines were assessed. Diagnostic criteria showed variability with no universal criterion shared amongst guidelines. Bronchoscopy was recommended by 90 % of guidelines, but the timing varied. The use of bronchoscopic scoring systems was recommended by four guidelines. Bronchoalveolar lavage (BAL) was recommended by four, with considerable variation in frequency and choice of lavage fluid. All guidelines advised at least one nebulised agent: heparin (n = 8); N-acetyl cysteine (NAC) (n = 8); or salbutamol (n = 8). All guidelines included advice on carbon monoxide poisoning; however, carboxyhaemoglobin (COHb) cut-off levels for treatment varied (5 % [n-4], 10 % [n = 3], 15 % [n = 1]). All recommended high-flow oxygen. Seven (70 %) guidelines offered guidance on cyanide poisoning. Reduced/altered consciousness was the only consistent diagnostic criterion. Five (50 %) guidelines provided intubation guidance, emphasising the role of a 'senior clinician' as the intubator. Ventilatory guidance appeared in eight guidelines, focusing on lung protective ventilation (n = 8); oxygenation goals (n = 3); and permissive hypercapnia (n = 3). Within lung-protective ventilation, advice on tidal volume (6, or 6-8 ml/kg) and plateau pressures (>30 cmH2O) were presented most commonly (n = 7).

CONCLUSION

This study has outlined the substantial variations in guidance for the management of SII. The results underscore the need for a national guideline outlining a standardised approach to the diagnosis and management of SII, within the limitations of the current evidence.

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

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.

Association of creatinine-albumin ratio with 28-day mortality in major burned patients: A retrospective cohort study

BACKGROUND

Serum creatinine (Cr) and Albumin (Alb) have emerged as prognostic factors for mortality in many diseases including burned patients. However, few studies report the relationship between Cr/Alb ratio and major burned patients. The purpose of this study is to make evaluation of efficacy of Cr/Alb ratio in predicting 28-day mortality in major burned patients.

METHOD

Based on a local largest tertiary hospital in South of China, we retrospectively analyzed data of 174 patients with total burn area surface (TBSA) ≥ 30% from January 2010 to December 2022. Receiver operating characteristic curve (ROC), logistic analysis, and Kaplan-Meier analysis were performed to evaluate the association between Cr/Alb ratio and 28-day mortality. Integrated discrimination improvement (IDI), and net reclassification improvement (NRI) were used to estimate the improvements in new model performance.

RESULTS

28-day mortality rate was 13.2% (23/174) in burned patients. Cr/Alb on admission at level of 3.340μmol/g showed the best discrimination between survivors and non-survivors after admission at 28 days. The result of multivariate logistic analysis suggested that age (OR, 1.058 [95%CI 1.016-1.102]; p = 0.006), higher FTSA (OR, 1.036 [95%CI 1.010-1.062]; p = 0.006), and higher level of Cr/Alb ratio (OR, 6.923 [95CI% 1.743-27.498]; p = 0.006) were independently associated with 28 day-mortality. A regression model was constructed by logit(p) = 0.057 *Age + 0.035 *FTBA + 1.935 * Cr/Alb - 6.822. The model showed a better discrimination and risk reclassification compared with ABSI and rBaux score.

CONCLUSIONS

High Cr/Alb ratio at admission is a herald of poor outcome. The model generated from multivariate analysis could serve as an alternative prediction tool among major burned patients.

Burn Registries State of Affairs: A Scoping review

Registry science allows for the interpretation of disease-specific patient data from secondary databases. It can be utilized to understand disease and injury, answer research questions, and engender benchmarking of quality-of-care indicators. Numerous burn registries exist globally, however, their contributions to burn care have not been summarized. The objective of this study is to characterize the available literature on burn registries. The authors conducted a scoping review, having registered the protocol a priori. A thorough search of the English literature, including grey literature, was carried out. Publications of all study designs were eligible for inclusion provided they utilized, analyzed, and/or critiqued data from a burn registry. Three hundred twenty studies were included, encompassing 16 existing burn registries. The most frequently used registries for peer-reviewed publications were the American Burn Association Burn Registry, Burn Model System National Database, and the Burns Registry of Australia and New Zealand. The main limitations of existing registries are the inclusion of patients admitted to burn centers only, deficient capture of outpatient and long-term outcome data, lack of data standardization across registries, and the paucity of studies on burn prevention and quality improvement methodology. Registries are an invaluable source of information for research, delivery of care planning, and benchmarking of processes and outcomes. Efforts should be made to stimulate other jurisdictions to build burn registries and for existing registries to be improved through data linkage with administrative databases, and by standardizing one international minimum dataset, in order to maximize the potential of registry science in burn care.

Care of the Critically Injured Burn Patient

Care of the critically injured burn patient presents unique challenges to the intensivist. Certified burn centers are rare and geographically sparse, necessitating that much of the initial management of patients with severe burn injuries must happen in the pre-burn center setting.1 Severe burn injuries often lead to a wide range of complications that extend beyond the loss of skin integrity and require specialized care. As such, medical intensivists are often called upon to stabilize these critically injured patients. This focused review outlines the clinical care of these medically complex patients, including airway management, post-burn complications, volume resuscitation, nutrition, and end-of-life care.

Positive signs on physical examination are not always indications for endotracheal tube intubation in patients with facial burn

Background

After clinical evaluation in the emergency department (ED), facial burn patients are usually intubated to protect their airways. However, the possibility of unnecessary intubation or delayed intubation after admission exists. Objective criteria for the evaluation of inhalation injury and the need for airway protection in facial burn patients are needed.

Methods

Facial burn patients between January 2013 and May 2016 were reviewed. Patients who were and were not intubated in the ED were compared. All the intubated patients received routine bronchoscopy and laboratory tests to evaluate whether they had inhalation injuries. The patients with and without confirmed inhalation injuries were compared. Multivariate logistic regression analysis was used to identify the independent risk factors for inhalation injuries in the facial burn patients. The reasons for intubation in the patients without inhalation injuries were also investigated.

Results

During the study period, 121 patients were intubated in the ED among a total of 335 facial burn patients. Only 73 (60.3%) patients were later confirmed to have inhalation injuries on bronchoscopy. The comparison between the patients with and without inhalation injuries showed that shortness of breath (odds ratio = 3.376, p = 0.027) and high total body surface area (TBSA) (odds ratio = 1.038, p = 0.001) were independent risk factors for inhalation injury. Other physical signs (e.g., hoarseness, burned nostril hair, etc.), laboratory examinations and chest X-ray findings were not predictive of inhalation injury in facial burn patients. All the patients with a TBSA over 60% were intubated in the ED even if they did not have inhalation injuries.

Conclusions

In the management of facial burn patients, positive signs on conventional physical examinations may not always be predictive of inhalation injury and the need for endotracheal tube intubation in the ED. More attention should be given to facial burn patients with shortness of breath and a high TBSA. Airway protection is needed in facial burn patients without inhalation injuries because of their associated injuries and treatments.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-022-00594-9.

Inpatient and post-discharge outcomes following inhalation injury among critically injured burn patients

Inhalation injury is associated with high inpatient mortality, but the impact of inhalation injury after discharge and on non-mortality outcomes are poorly characterized. To address this gap, we evaluated the effect of inhalation injury on post-discharge morbidity, mortality and hospital readmissions among patients who sustained burn injury, as well as on in-hospital outcomes for context.This was a retrospective cohort study of patients with cutaneous fire/flame burns admitted to a burn center intensive care unit from 1/1/2009-12/31/2015, with or without inhalation injury. Records were linked to statewide hospital admission and vital statistics databases to assess post-discharge outcomes. Mixed-effects Poisson regression was used to assess mortality, complications, and readmissions. The overall cohort included 830 patients with cutaneous burns; of these, 201 patients had inhalation injury. In-hospital mortality was 31% among inhalation injury patients versus 6% in patients without inhalation injury (adjusted OR 2.35; 95% CI 1.66-3.31). Inhalation injury was also associated with an increased risk of in-hospital pneumonia and tracheostomy (p<0.05 for all). Inhalation injury was not associated with greater post-discharge mortality, all-cause readmission, readmission for pulmonary diagnosis, or readmission requiring intubation. Among the subset of patients with bronchoscopy-confirmed inhalation injury (n=124; 62% of inhalation injuries), higher injury grade was not associated with greater inpatient or post-discharge mortality. Inhalation injury was associated with increased early morbidity and mortality, but did not contribute to post-discharge mortality or readmission. These findings have implications for shared decision-making with patients and families, and for estimating healthcare utilization after initial hospitalization.

Advances in airway management and mechanical ventilation in inhalation injury

PURPOSE OF REVIEW

Airway management, mechanical ventilation, and treatment of systemic poisoning in burn patients with inhalation injury remains challenging. This review summarizes new concepts as well as open questions.

RECENT FINDINGS

Several life-threatening complications, such as airway patency impairment and respiratory insufficiency, can arise in burn patients and require adequate and timely airway management. However, unnecessary endotracheal intubation should be avoided. Direct visual inspection via nasolaryngoscopy can guide appropriate airway management decisions. In cases of lower airway injury, bronchoscopy is recommended to remove casts and estimate the extent of the injury in intubated patients. Several mechanical ventilation strategies have been studied. An interesting modality might be high-frequency percussive ventilation. However, to date, there is no sound evidence that patients with inhalation injury should be ventilated with modes other than those applied to non-burn patients. In all burn patients exposed to enclosed fire, carbon monoxide as well as cyanide poisoning should be suspected. Carbon monoxide poisoning should be treated with an inspiratory oxygen fraction of 100%, whereas cyanide poisoning should be treated with hydroxocobalamin.

SUMMARY

Burn patients need specialized care that requires specific knowledge about airway management, mechanical ventilation, and carbon monoxide and cyanide poisoning.

Epidemiology and Outcome Analysis of Burns During Explosion Accident at a Major Center in Southwestern China From 2002 to 2016

Explosions always lead to serious public health, social, and economic problems. We investigated the epidemiology, outcomes, and costs of burn patients caused by explosion accident in Southwest China to explore more effective prevention and treatment strategies. This retrospective study included 497 inpatients with burns during explosion accident admitted to the Institute of Burn Research of Army Medical University from 2002 to 2016. A total of 497 cases (77.78% males) were found, accounting for 2.37% of the total burn patients. The average age was 34.38 ± 15.02 years. The most common etiology was gas explosions (51.51%). Most of the cases were caused by work-related activities. The average TBSA was 31.30 ± 28.32%. The median length of stay (LOS) was 31 days. The LOS was correlated with TBSA, full-thickness burns, older age, number of operations and outcome. The major factors determining the cost were larger TBSA, full-thickness burns, and higher cure rate. The mortality was 6.44%. Larger TBSA and older age were the most important risk factors for the mortality. This study suggested that special attention should be paid to prevent burns during explosion accident in adult males with occupational exposure. In the future, more effective and practical strategies for preventing and treating burns during explosion accident based on related risk factors should be implemented.

The Predictive Applicability of Liberal vs Restrictive Intubation Criteria in Adult Patients With Suspected Inhalation Injury-A Retrospective Cohort Study

This study compares the ability of liberal vs restrictive intubation criteria to detect prolonged intubation and inhalation injury in burn patients with suspected inhalation injury. Emerging evidence suggests that using liberal criteria may lead to unnecessary intubation in some patients. A single-center retrospective cohort study was conducted in adult patients with suspected inhalation injury admitted to intensive care at Queen Elizabeth Hospital, Birmingham between April 2016 and July 2019. Liberal intubation criteria, as reflected in local guidelines, were compared to restrictive intubation criteria, as outlined in the American Burn Association guidelines. The number of patients displaying positive characteristics from either guideline was compared to the number of patients who had prolonged intubation (more than 48 hours) and inhalation injury. In detecting a need for prolonged intubation (n = 85), the liberal criteria had greater sensitivity (liberal = 0.98 [0.94-1.00] vs restrictive = 0.84 [0.75-0.93]; P = .013). However, the restrictive criteria had greater specificity (restrictive = 0.96 [0.89-1.00] vs liberal = 0.48 [0.29-0.67]; P < .001). In detecting inhalation injury (n = 72), the restrictive criteria were equally sensitive (restrictive = 0.94 [0.87-1.00] vs liberal = 0.98 [0.84-1.00]; P = .48) and had greater specificity (restrictive = 0.86 [0.72-1.00] vs liberal = 0.04 [0.00-0.13]; P < .001). In patients who met liberal but not restrictive criteria, 65% were extubated within 48 hours and 90% did not have inhalation injury. Liberal intubation criteria were more sensitive at detecting a need for prolonged intubation, while restrictive criteria were more specific. Most patients intubated based on liberal criteria alone were extubated within 48 hours. Restrictive criteria were highly sensitive and specific at detecting inhalation injury.