Severity of Inhalation Injury and Risk of Nosocomial Pneumonia: A Retrospective Cohort Study.

BACKGROUND: The impact of inhalation injury on risk of nosocomial pneumonia (NP), an important complication in patients with burns, is not well established. RESEARCH QUESTION: Is more severe inhalation injury associated with increased risk of NP? STUDY DESIGN AND METHODS: We performed a retrospective cohort study of patients with suspected inhalation injury admitted to a regional burn center from 2011 to 2022 who underwent diagnostic bronchoscopy within 48 h of admission. We estimated the association of high-grade inhalation injury (Abbreviated Injury Scale score 3 and 4) vs low-grade inhalation injury (Abbreviated Injury Scale score 1 and 2) with NP adjusted for age, burn size, and comorbid obstructive lung disease. Death and hospital discharge were considered competing risks. RESULTS: Of the 245 patients analyzed, 51 (21%) had high-grade injury, 180 (73%) had low-grade injury, and 14 (6%) had no inhalation injury. Among the 236 patients hospitalized for ≥ 48 h, NP occurred in 24 of 50 patients (48%) in the high-grade group, 54 of 172 patients (31%) in the low-grade group, and two of 14 patients (14%) in the no inhalation injury group. High-grade (vs low-grade) inhalation injury was associated with higher hazard of NP in both the proportional cause-specific hazard model (cause-specific hazard ratio, 2.04; 95% CI, 1.26-3.30; P = .004) and Fine-Gray subdistribution hazard model (subdistribution hazard ratio for NP, 2.24; 95% CI, 1.38-3.64; P = .001). INTERPRETATION: Among patients with inhalation injury, more severe injury was associated with higher hazard of NP in competing risk analysis. Additional research is needed to investigate mechanisms that may explain the relationship between inhalation injury and NP and to identify more effective risk reduction strategies.

A National Mandate for Thermal Fuses for Home Oxygen Users is Cost-effective in the Prevention of Burn Morbidity, Mortality and Property Loss.

Smoking while using home oxygen leads to explosions which cause cutaneous burns, death, and loss of property. Thermal fuses interrupt the propagation of ignited oxygen-lines and reduce the risk of injury. Prior to mandating thermal fuses for all home oxygen users in the US, cost-effectiveness analysis should be performed. A Markov model was constructed for suffering thermal injury while smoking on home oxygen. Societal and Medicare perspectives were adopted evaluating the costs of a federal policy including purchasing/shipping thermal fuses to all home oxygen users. Costs included the healthcare required to treat burn patients and extending lives in advanced chronic obstructive pulmonary disease. Cost savings included the avoided property loss. Effectiveness was measured in gains in quality adjusted life years (QALYS). In the status quo, the 10-year societal cost was $28.67 billion compared to $28.36 billion in the policy mandate (saving $305.40 million at ten years). 1,812 QALYs were gained with the policy mandate, yielding and ICER of -$160,317. For the Medicare payor perspective, the incremental cost-effectiveness ratio (ICER) was $64,981. Deterministic and probabilistic sensitivity analyses showed little variation in the ICER under multiple scenarios. The discrepancy between the dominant ICER for societal perspective and cost-effective ICER for Medicare perspective reflected savings from averted property loss not realized by Medicare. A national policy mandating and paying for thermal fuses for all home oxygen users is dominant from a societal perspective and cost-effective from a Medicare perspective. The US government should adopt such a policy.

Inhalation Injury.

Inhalation injury is a critical component of thermal injury that can significantly increase mortality in burn survivors. This poses significant challenges to managing these patients and profoundly impacts patient outcomes. This comprehensive literature review delves into the epidemiology, pathophysiology, diagnosis, classification, management, and outcomes of inhalation injury with burns.

The impact of inhalation injury on fluid resuscitation in major burn patients: a 10-year multicenter retrospective study.

BACKGROUND: It remains unclear whether additional fluid supplementation is necessary during the acute resuscitation period for patients with combined inhalational injury (INHI) under the guidance of the Third Military Medical University (TMMU) protocol. METHODS: A 10-year multicenter, retrospective cohort study, involved patients with burns ≥ 50% total burn surface area (TBSA) was conducted. The effect of INHI, INHI severity, and tracheotomy on the fluid management in burn patients was assessed. Cumulative fluid administration, cumulative urine output, and cumulative fluid retention within 72 h were collected and systematically analyzed. RESULTS: A total of 108 patients were included in the analysis, 85 with concomitant INHI and 23 with thermal burn alone. There was no significant difference in total fluid administration during the 72-h post-burn between the INHI and non-INHI groups. Although no difference in the urine output and fluid retention was shown in the first 24 h, the INHI group had a significantly lower cumulative urine output and a higher cumulative fluid retention in the 48-h and 72-h post-burn (all p < 0.05). In addition, patients with severe INHI exhibited a significantly elevated incidence of complications (Pneumonia, 47.0% vs. 11.8%, p = 0.012), (AKI, 23.5% vs. 2.9%, p = 0.037). For patients with combined INHI, neither the severity of INHI nor the presence of a tracheotomy had any significant influence on fluid management during the acute resuscitation period. CONCLUSIONS: Additional fluid administration may be unnecessary in major burn patients with INHI under the guidance of the TMMU protocol.

The impact and validity of the Berlin criteria on burn-induced ARDS: Examining mortality rates, and inhalation injury influences. A single center observational cohort study.

BACKGROUND: As several recent studies have shown low mortality rates in burn injury induced ARDS early (≤7 days) after the burn, the Berlin criteria for the ARDS diagnosis in this setting may be disputed. Related to this issue, the present study investigated the incidence, trajectory and risk factors of early Acute Respiratory Distress Syndrome (ARDS) and outcome in burn patients, as per the Berlin criteria, along with the concurrent prevalence and influence of inhalation injury, and ventilator-acquired pneumonia (VAP). METHODS: Over a 2.5-year period, burn patients with Total Burn Surface Area (TBSA) exceeding 10% admitted to a national burn center were included. The subgroup of interest comprised patients with more than 48 h of ventilatory support. This group was assessed for ARDS, inhalation injury, and VAP. RESULTS: Out of 292 admissions, 62 sustained burns > 10% TBSA. Of these, 28 (45%) underwent ventilatory support for over 48 h, almost all, 24 out of 28, meeting the criteria for ARDS early, within 7 days post-injury and with a PaO2/FiO2 (PF) ratio nadir at day 5. The mortality rate for this early ARDS group was under 10%, regardless of PF ratios (mean TBSA% 34,8%). Patients with concurrent inhalation injury and early ARDS showed significantly lower PF ratios (p < 0.001), and higher SOFA scores (p = 0.004) but without impact on mortality. Organ failure, indicated by SOFA scores, peaked early (day 3) and declined in the first week, mirroring PF ratio trends (p < 0.001). CONCLUSIONS: The low mortality associated with early ARDS in burn patients in this study challenges the Berlin criteria's for the early ARDS diagnosis, which for its validity relies on that higher mortality is linked to worsening PF ratios. The finding suggests alternative mechanisms, leading to the early ARDS diagnosis, such as the significant impact of inhalation injury on early PF ratios and organ failure, as seen in this study. The concurrence of early organ failure with declining PF ratios, supports, as expected, the hypothesis of trauma-induced inflammation/multi-organ failure mechanisms contributing to early ARDS. The study highlights the complexity in differentiating between the contributions of inhalation injury to early ARDS and the related organ dysfunction early in the burn care trajectory. The Berlin criteria for the ARDS diagnosis may not be fully applicable in the burn care setting, where the low mortality significantly deviates from that described in the original Berlin ARDS criteria publication but is as expected when considering the actual not very extensive burn injury sizes/Baux scores as in the present study.

El humo del electrocauterio, el riesgo olvidado y minimizado de la cirugía / Smoke from electrocautery, the forgotten and minimized risk of surgery

Introducción. La nueva era de la cirugía es cada vez más dependiente de la tecnología, y un ejemplo de ello es el uso generalizado de electrocauterio como parte primordial de la práctica quirúrgica. El humo quirúrgico es un subproducto de la disección y la coagulación de los tejidos producidas por los equipos de energía, que representa múltiples riesgos potenciales para la salud del grupo quirúrgico, sin embargo, se han minimizado los peligros causados por la exposición de manera frecuente y acumulativa a este aerosol. Métodos. Se realizó un análisis crítico, desde una posición reflexiva de la información disponible, estableciendo los posibles riesgos relacionados con la exposición al humo quirúrgico. Discusión. Es visible la necesidad imperativa de establecer directrices nacionales, pautas normativas y recomendaciones estandarizadas para cumplir con las exigencias dadas por los sistemas de gestión en salud ocupacional y seguridad del trabajo, cuyo objetivo principal es hacer efectivo el uso de mascarillas quirúrgicas apropiadas, la implementación de programa de vigilancia epidemiológica ambiental en sala de cirugía, la priorización del uso constante de aspiradores y sistemas de evacuación, y la ejecución de programas educativos de sensibilización dirigidos al personal implicado. De igual manera, se abre la inquietud de la necesidad de nuevos estudios para definir con mayor precisión el peligro de este aerosol. Conclusión. Se recomienda de manera responsable utilizar todas las estrategias preventivas existentes para intervenir en salas de cirugía los riesgos minimizados y olvidados del humo quirúrgico.

Introduction. The new era of surgery is increasingly dependent on technology, and an example of this is the widespread use of electrocautery as a primary part of surgical practice. Surgical smoke is a byproduct of the dissection and coagulation of tissues produced by energy equipment, which represents multiple potential health risks for the surgical group; however, the dangers caused by cumulative exposure have been minimized. Methods. A critical analysis was carried out from a reflective position of the available information, establishing the possible risks related to exposure to surgical smoke. Discussion. The imperative need to establish national normative guidelines and standardized recommendations to comply with the demands given by the occupational health and work safety management systems, whose main objective is to make effective the use of appropriate surgical masks, implementation of environmental epidemiological surveillance program in the operating room, prioritizing the constant use of vacuum cleaners and evacuation systems, and carrying out educational awareness programs aimed at the personnel involved. Likewise, there is concern about the need for new studies to more precisely define the danger of this aerosol. Conclusion. It is recommended to responsibly use all existing preventive strategies to intervene in operating rooms to minimize the forgotten risks of surgical smoke.

Impact of Wildfires on Cardiovascular Health.

Wildfire smoke (WFS) is a mixture of respirable particulate matter, environmental gases, and other hazardous pollutants that originate from the unplanned burning of arid vegetation during wildfires. The increasing size and frequency of recent wildfires has escalated public and occupational health concerns regarding WFS inhalation, by either individuals living nearby and downstream an active fire or wildland firefighters and other workers that face unavoidable exposure because of their profession. In this review, we first synthesize current evidence from environmental, controlled, and interventional human exposure studies, to highlight positive associations between WFS inhalation and cardiovascular morbidity and mortality. Motivated by these findings, we discuss preventative measures and suggest interventions to mitigate the cardiovascular impact of wildfires. We then review animal and cell exposure studies to call attention on the pathophysiological processes that support the deterioration of cardiovascular tissues and organs in response to WFS inhalation. Acknowledging the challenges of integrating evidence across independent sources, we contextualize laboratory-scale exposure approaches according to the biological processes that they model and offer suggestions for ensuring relevance to the human condition. Noting that wildfires are significant contributors to ambient air pollution, we compare the biological responses triggered by WFS to those of other harmful pollutants. We also review evidence for how WFS inhalation may trigger mechanisms that have been proposed as mediators of adverse cardiovascular effects upon exposure to air pollution. We finally conclude by highlighting research areas that demand further consideration. Overall, we aspire for this work to serve as a catalyst for regulatory initiatives to mitigate the adverse cardiovascular effects of WFS inhalation in the community and alleviate the occupational risk in wildland firefighters.

Rare multi-fungal sepsis: a case of triple-impact immunoparalysis.

Patients with burn injury and inhalation injury are highly susceptible to infectious complications, including opportunistic pathogens, due to the loss of skin cover and mucosal damage of respiratory tract as well as the disruption of homeostasis. This case report, a 34-year-old man suffered critical burns, provides the first literature description of triple-impact immunoparalysis (critical burns, inhalation injury, and SARS-CoV-2 infection), leading to a lethal multifocal infection caused by several fungi including very rare environmental representatives Metschnikowia pulcherrima and Wickerhamomyces anomalus. The co-infection by these common environmental yeasts in a human is unique and has not yet been described in the literature. Importantly, our patient developed refractory septic shock and died despite targeted antifungal therapy including the most potent current antifungal agent-isavuconazole. It can be assumed that besides immunoparalysis, effectiveness of therapy by isavuconazole was impaired by the large distribution volume in this case. As this is a common situation in intensive care patients, routine monitoring of plasmatic concentration of isavuconazole can be helpful in personalization of the treatment and dose optimization. Whatmore, many fungal species often remain underdiagnosed during infectious complications, which could be prevented by implementation of new methods, such as next-generation sequencing, into clinical practice.

New Treatment Modality for Burn Injury-Related Acute Respiratory Distress Syndrome: High-Flow Nasal Oxygen Therapy in Major Burns.

Pulmonary insufficiency is the primary cause of death in cases of major burns accompanied by inhalation damage. It is important to consider the impact on the face and neck in flame burns. Early implementation of bronchial hygiene measures and oxygenation treatment in inhalation injury can reduce mortality. This case series presents the effects of high-flow nasal oxygen (HFNO) application on patient outcomes in major burns and inhalation injury. This report discusses 3 different patients. One patient, a 29-year-old male with 35% TBSA burns, received HFNO treatment for inhalation injury on the sixth day after the trauma. After 72 hours of HFNO application, the patient's pulmonary symptoms improved. The second patient had 60% TBSA burns and developed respiratory distress symptoms on the fifth day after the trauma. After 7 days of HFNO application, all symptoms and findings of acute respiratory distress syndrome (ARDS) were resolved. HFNO has been used for the treatment of ARDS related to major burn (60% of burned TBSA) in a 28-year-old patient, and improvement was achieved. The use of HFNO in pulmonary insufficiency among burn patients has not been reported previously. This series of patient cases demonstrates the successful application of HFNO in treating inhalation injury and burn-related ARDS. However, further clinical studies are necessary to increase its clinical utilization.

Characterization and prevention of flame burns caused by electric bicycle battery chargers: results from a 7-year experience.

OBJECTIVE: With the recent exponential increase in express deliveries across China, the number of patients with flame burns caused by electric bicycle battery chargers (BEBBC) has markedly increased in burn units. In this study, we aimed to characterize BEBBC to systematically explore measures to prevent their occurrence. METHODS: We performed a retrospective chart review of patients with flame burns who visited the Burn Department of Rui Jin Hospital between January 2015 and December 2021. RESULTS: Sixty-three patients with BEBBC and 1412 with types of other flame burn were included in this study. Fifty-six of the 63 BEBBC cases occurred between 9 pm and 7 am. BEBBC incidents involved a higher incidence of group burn in which multiple individuals were affected. Non-local patients with BEBBC were significantly younger than their local counterparts. BEBBC had a higher mortality than types of other flame burn. CONCLUSIONS: The rising incidence of BEBBC calls for greater attention because of the associated high mortality and heavy burden on society. Enacting related legislation, disseminating information to the public, and improving treatment to control infection can help prevent BEBBC, increase its cure rate, and reduce patient mortality.

Inhalation Injury, Respiratory Failure, and Ventilator Support in Acute Burn Care.

Sustaining an inhalation injury increases the risk of severe complications and mortality. Current evidential support to guide treatment of the injury or subsequent complications is lacking, as studies either exclude inhalation injury or design limit inferences that can be made. Conventional ventilator modes are most commonly used, but there is no consensus on optimal strategies. Settings should be customized to patient tolerance and response. Data for pharmacotherapy adjunctive treatments are limited.

Extracorporeal Membrane Oxygenation in a Patient with Severe Inhalation Injury: Multidisciplinary Burn Team Care.

INTRODUCTION: Inhalation injury is a major risk factor for mortality in burn patients via 3 primary mechanisms: airway edema and obstruction, hypoxemic respiratory failure, and pneumonia. Currently, the mainstay of treatment is supportive care to include early intubation, lung-protective or high-frequency-percussive mechanical ventilation, nebulized heparin, and aggressive pulmonary toilet. Despite these treatments, a subset of these patients progress to severe acute respiratory distress syndrome (ARDS) for which rescue options are limited. CASE PRESENTATION: A 31-year-old woman was found down in a house fire. On admission to the burn intensive care unit, she was diagnosed with grade 3 smoke inhalation injury. Cutaneous thermal injury was absent. By hospital day 2, she developed worsening hypoxemia and hypercapnia despite maximal ventilatory support. She was placed on veno-venous extracorporeal membrane oxygenation (ECMO). She received an average of 2.2 hours of direct rehabilitation a day and completed out-of-bed modalities over 90% of total hospital days. After 159 hours, she was decannulated, and by hospital day 18, she was discharged home on supplemental oxygen. CONCLUSION: Current literature regarding ECMO in inhalation injury is limited, but a growing body of evidence suggests that treatment of severe smoke inhalation injury should include ECMO for those who fail conventional therapy.

Evaluation of hydroxocobalamin use for the treatment of suspected cyanide toxicity secondary to smoke inhalation.

Hydroxocobalamin is used for cyanide toxicity after smoke inhalation, but diagnosis is challenging. Retrospective studies have associated hydroxocobalamin with acute kidney injury (AKI). This is a retrospective analysis of patients receiving hydroxocobalamin for suspected cyanide toxicity. The primary outcome was the proportion of patients meeting predefined appropriate use criteria defined as ≥1 of the following: serum lactate ≥8 mmol/L, systolic blood pressure (SBP) <90 mmHg, new-onset seizure, cardiac arrest, or respiratory arrest. Secondary outcomes included incidence of AKI, pneumonia, resolution of initial neurologic symptoms, and in-hospital mortality. Forty-six patients were included; 35 (76%) met the primary outcome. All met appropriate use criteria due to respiratory arrest, 15 (43%) for lactate, 14 (40%) for SBP, 12 (34%) for cardiac arrest. AKI, pneumonia, and resolution of neurologic symptoms occurred in 30%, 21%, and 49% of patients, respectively. In-hospital mortality was higher in patients meeting criteria, 49% vs. 9% (95% CI 0.16, 0.64). When appropriate use criteria were modified to exclude respiratory arrest in a post-hoc analysis, differences were maintained, suggesting respiratory arrest alone is not a critical component to determine hydroxocobalamin administration. Predefined appropriate use criteria identify severely ill smoke inhalation victims and provides hydroxocobalamin treatment guidance.

An atypical airway cast.

A 60-year-old man intubated for airway protection after smoke inhalation was found to have decompensated hypercapnic respiratory failure. Fiberoptic bronchoscopy revealed obstructive airway slough and pseudomembrane, a manifestation of severe inhalation injury. Veno-venous extracorporeal membrane oxygenation was established for stabilization. The airway casts were removed successfully with periprocedural veno-venous extracorporeal membrane oxygenation support.

Do pre-burn center management algorithms work? Evaluation of pre-admission diagnosis and treatment adequacy of burn patients referred to a burn center.

Interventions for burn management until the patient is transferred to a burn center affect mortality and morbidity. Therefore, adherence to the developed algorithms is an important issue. This study aimed to determine deficiencies in different aspects of the implementation of these algorithms during the pre-admission diagnosis and treatment processes of patients referred to our burn center. This study involved a 4-year review of patients referred to our burn center. One hundred and seventy burn cases admitted by referral were enrolled in the study. Adequacy of resuscitation within the first 24 hours, adherence to guidelines, and mortality were investigated. Resuscitation performed within the first 24 hours was found to be inadequate in 88 patients (51.8%). When the burned surface area percentages were evaluated all percentages were calculated higher before arrival. There were 78 major burn cases (45.9%), and the frequency of inhalation burns, intubation requirements and renal failure were more common in this group compared to the minor burn group (P < .001). The frequency of intubation without accurate indications was found to be 70.58%. Inadequate escharotomy was detected at a rate of 52.9%, and inadequate fasciotomy at a rate of 66.6%. The mortality rate was 22.4% among all patients. Interventions undertaken during the period until the patients' referral to these centers affect mortality and morbidity. In this study, it was found that the pre-hospital applications generated were insufficient, and it was proposed that burn patient care algorithms be developed with in-service training throughout the country.

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.

A Rare Mechanism of Inhalation Injury: Direct Thermal Damage to the Lower Airway.

In patients with inhalation injury associated with major burns, the primary mechanism of tissue harm depends on the location within the respiratory tract. Proximal to the trachea, the upper respiratory tract epithelium is classically injured via direct thermal injury. Such injury occurs due to the inhalation of high-temperature air. These upper airway structures and the tracheobronchial tree's dense vasculature protect the lower airways and lung parenchyma from direct thermal damage. The lower respiratory tract epithelium and lung parenchyma typically become injured secondary to the cytotoxic effects of chemical irritants inhaled in smoke as well as delayed inflammatory host responses. This paper documents a rare case in which a patient demonstrated evidence of direct thermal injury to the lower respiratory tract epithelium. A 26-year-old Caucasian male presented to the emergency room with 66% total body surface area thermal burns and grade 4 inhalation injury after a kitchen fire. Instead of visualizing carbonaceous deposits in the bronchi, a finding common in inhalation injury, initial bronchoscopy revealed bronchial mucosa carpeted with hundreds of bullae. Despite the maximum grade of inhalation injury per the abbreviated injury score and a 100% chance of mortality predicted with the revised Baux score, as well as a clinical course complicated by pneumonia development, bacteremia, and polymicrobial external wound infection, this patient survived. This dissonance between his expected and observed clinical outcome suggests that the applicability of current inhalation injury classification systems depends on the precise mechanism of injury to the respiratory tract. The flaws of these grading scales and prognostic indicators may be rooted in their failure to account for other pathophysiologic processes involved in inhalation injury. It may be necessary to develop new grading and prognostic systems for inhalation injury that acknowledge and better account for unusual pathophysiologic mechanisms of tissue damage.

Intravenous Autologous Bone Marrow-derived Mesenchymal Stromal Cells Delay Acute Respiratory Distress Syndrome in Swine.

Rationale: Early post injury mitigation strategies in ARDS are in short supply. Treatments with allogeneic stromal cells are administered after ARDS develops, require specialized expertise and equipment, and to date have shown limited benefit. Objectives: Assess the efficacy of immediate post injury intravenous administration of autologous or allogeneic bone marrow-derived mesenchymal stromal cells (MSCs) for the treatment of acute respiratory distress syndrome (ARDS) due to smoke inhalation and burns. Methods: Yorkshire swine (n = 32, 44.3 ± 0.5 kg) underwent intravenous anesthesia, placement of lines, severe smoke inhalation, and 40% total body surface area flame burns, followed by 72 hours of around-the-clock ICU care. Mechanical ventilation, fluids, pressors, bronchoscopic cast removal, daily lung computed tomography scans, and arterial blood assays were performed. After injury and 24 and 48 hours later, animals were randomized to receive autologous concentrated bone marrow aspirate (n = 10; 3 × 106 white blood cells and a mean of 56.6 × 106 platelets per dose), allogeneic MSCs (n = 10; 6.1 × 106 MSCs per dose) harvested from healthy donor swine, or no treatment in injured control animals (n = 12). Measurements and Main Results: The intravenous administration of MSCs after injury and at 24 and 48 hours delayed the onset of ARDS in swine treated with autologous MSCs (48 ± 10 h) versus control animals (14 ± 2 h) (P = 0.004), reduced ARDS severity at 24 (P < 0.001) and 48 (P = 0.003) hours, and demonstrated visibly diminished consolidation on computed tomography (not significant). Mortality at 72 hours was 1 in 10 (10%) in the autologous group, 5 in 10 (50%) in the allogeneic group, and 6 in 12 (50%) in injured control animals (not significant). Both autologous and allogeneic MSCs suppressed systemic concentrations of TNF-α (tumor necrosis factor-α). Conclusions: The intravenous administration of three doses of freshly processed autologous bone marrow-derived MSCs delays ARDS development and reduces its severity in swine. Bedside retrieval and administration of autologous MSCs in swine is feasible and may be a viable injury mitigation strategy for ARDS.

Outcomes of Tracheostomy on Burn Inhalation Injury.

Background: Tracheostomy has been proposed for patients with expected prolonged intubation. This study aims to determine the outcomes of tracheostomy on patients with burn inhalation injuries requiring mechanical ventilation. Methods: This study is a retrospective review from 2011 to 2019. Inclusion criteria were recording of inhalation injury, ventilator support (at least 24 hours), and total body surface area of <15%. The patients were stratified into 2 groups: tracheostomy (group 1) versus no tracheostomy (group 2). The outcome measures were in-hospital mortality rate, hospital length of stay, intensive care unit length of stay, ventilator days, and ventilator- associated pneumonia (VAP). Results: A total of 33 burn patients met our inclusion criteria. Group 1 consisted of 10 patients and group 2 of 23 patients. There was no statistically significant difference in terms of percent total body surface area. There was a higher intensive care unit length of stay at 23.8 days in group 1 compared with 3.16 days in group 2, a higher hospital length of stay at 28.4 days in group 1 compared with 5.26 days in group 2, and higher ventilator days in group 1 with 20.8 days compared with 2.5 days in group 2. There was no statistically significant difference between the 2 groups in terms of mortality. The incidence of VAP was also significantly higher in group 1 than in group 2. Conclusions: The ideal timing and implementation of tracheostomy with inhalation injury has yet to be determined. In this study, tracheostomy was associated with much longer lengths of stay and pneumonia. The impact of the underlying lung injury versus the tracheostomy itself on these observations is unclear. The challenge of characterizing the severity of an inhalation injury based on early visual inspection remains.