Intrabronchial surfactant application in cases of inhalation injury: first results from patients with severe burns and ARDS

Transcriptional Characterization of Bronchoalveolar Lavage Fluid Reveals Immune Microenvironment Alterations in Chemically Induced Acute Lung Injury

Purpose

Chemically induced acute lung injury (CALI) has become a serious health concern in our industrialized world, and abnormal functional alterations of immune cells crucially contribute to severe clinical symptoms. However, the cell heterogeneity and functional phenotypes of respiratory immune characteristics related to CALI remain unclear.

Methods

We performed scRNA sequencing on bronchoalveolar lavage fluid (BALF) samples obtained from phosgene-induced CALI rat models and healthy controls. Transcriptional data and TotalSeq technology were used to confirm cell surface markers identifying immune cells in BALF. The landscape of immune cells could elucidate the metabolic remodeling mechanism involved in the progression of acute respiratory distress syndrome and cytokine storms. We used pseudotime inference to build macrophage trajectories and the corresponding model gene expression changes, and identified and characterized alveolar cells and immune subsets that may contribute to CALI pathophysiology based on gene expression profiles at single-cell resolution.

Results

The immune environment of cells, including dendritic cells and specific macrophage subclusters, exhibited increased function during the early stage of pulmonary tissue damage. Nine different subpopulations were identified that perform multiple functional roles, including immune responses, pulmonary tissue repair, cellular metabolic cycle, and cholesterol metabolism. Additionally, we found that individual macrophage subpopulations dominate the cell-cell communication landscape. Moreover, pseudo-time trajectory analysis suggested that proliferating macrophage clusters exerted multiple functional roles.

Conclusion

Our findings demonstrate that the bronchoalveolar immune microenvironment is a fundamental aspect of the immune response dynamics involved in the pathogenesis and recovery of CALI.

"Awake" Extracorporeal Membrane Oxygenation Combined With Continuous Renal Replacement Therapy For the Treatment of Severe Chemical Gas Inhalation Lung Injury

Lung injury caused by chemical gas inhalation is a common clinically severe disease that very easily progresses to acute respiratory distress syndrome (ARDS). Traditional respiratory support consists mainly of mechanical ventilation, but the prognosis of this condition is still poor. "Awake" extracorporeal membrane oxygenation (ECMO) maintains oxygenation, improves ventilation, adequately allows the injured lungs to rest, and avoids complications associated with sedation, intubation, and mechanical ventilation. Continuous renal replacement therapy (CRRT) can provide better fluid management and reduce pulmonary edema. Herein, we describe the case of a patient with severe chemical gas inhalation lung injury who failed to respond to traditional mechanical ventilation and was subsequently treated with awake ECMO combined with CRRT.

Surfactant therapy for acute respiratory distress in severe pediatric burn injury: a case series

After severe burn injury, pediatric patients often succumb to complications of respiratory failure. Surfactant has been used to improve pulmonary gas exchange for severe respiratory distress in other pediatric populations but has not been studied in pediatric burn-injured patients. Here, the authors report a case series of seven severely burned pediatric patients who received surfactant for acute respiratory distress and severe hypoxemia. Seven cases were reviewed of pediatric patients who received surfactant for severe acute respiratory distress. Data analyzed included age, TBSA burned, height, weight, mechanism of injury, total intensive care unit days, hospital days, and ventilator days. Modes of ventilation, peak inspiratory pressure, oxygen requirement, arterial blood gas analysis, blood pressure, and heart rate were analyzed before and the day following surfactant therapy. Four patients had reduced oxygen requirements following surfactant administration (FiO(2): 0.66 ± 0.23-0.48 ± 0.025). Three patients showed no reduction in oxygen requirements (FiO(2): 0.95 ± 0.09-0.90 ± 0.0). The remaining four patients who had reduced oxygen requirements received surfactant earlier following their injury (4.8 ± 0.9 days postinjury vs 17.7 ± 8 days postinjury) and had less derangement in oxygenation before surfactant dosing (PaO(2):FiO(2) ratio: 105.2 ± 26.4 vs 64.5 ± 5.2). Surfactant therapy may offer a therapeutic option during acute respiratory distress for severely burned pediatric patients. Surfactant may be useful early in the course of severe hypoxemia and acute respiratory distress but may not be effective as a salvage modality.

Burn injuries

PURPOSE OF REVIEW

To summarize new advances and research findings that relate to the treatment of burn victims.

RECENT FINDINGS

Recent advances in burn resuscitation and critical care reflect a better understanding of the acute phase pathophysiology of severe burns. Aggressive management of the unstable burn airway is always the most important clinical priority. Emphasis has been placed on the early identification of inhalation injury and its impact on fluid resuscitation, as well as on a protective lung strategy to reduce the development of pulmonary edema, acute lung injury and pneumonia, and to reduce the risk of barotrauma. New blood markers, such as serum cholinesterase and inflammatory cytokines, have been introduced to assist in the prognosis of morbidity and mortality, beyond the traditional vital signs. At this time, however, these are available only for research purposes. Finally, early burn wound excision and coverage with new biodegradable materials results in less pain and more rapid healing for the patient.

SUMMARY

The combination of innovative approaches and a dedicated burn team is expected to continue to improve survival in the next few years even in the most severe cases.

Exogenous pulmonary surfactant for the treatment of adult patients with acute respiratory distress syndrome: results of a meta-analysis

INTRODUCTION

The purpose of this study was to perform a systematic review and meta-analysis of exogenous surfactant administration to assess whether this therapy may be useful in adult patients with acute respiratory distress syndrome.

METHODS

We performed a computerized literature search from 1966 to December 2005 to identify randomized clinical trials. The primary outcome measure was mortality 28-30 days after randomization. Secondary outcome measures included a change in oxygenation (PaO2:FiO2 ratio), the number of ventilation-free days, and the mean duration of ventilation. Meta-analysis was performed using the inverse variance method.

RESULTS

Two hundred and fifty-one articles were identified. Five studies met our inclusion criteria. Treatment with pulmonary surfactant was not associated with reduced mortality compared with the control group (odds ratio 0.97; 95% confidence interval (CI) 0.73, 1.30). Subgroup analysis revealed no difference between surfactant containing surface protein or not - the pooled odds ratio for mortality was 0.87 (95% CI 0.48, 1.58) for trials using surface protein and the odds ratio was 1.08 (95% CI 0.72, 1.64) for trials without surface protein. The mean difference in change in the PaO2:FiO2 ratio was not significant (P = 0.11). There was a trend for improved oxygenation in the surfactant group (pooled mean change 13.18 mmHg, standard error 8.23 mmHg; 95% CI -2.95, 29.32). The number of ventilation-free days and the mean duration of ventilation could not undergo pooled analysis due to a lack of sufficient data.

CONCLUSION

Exogenous surfactant may improve oxygenation but has not been shown to improve mortality. Currently, exogenous surfactant cannot be considered an effective adjunctive therapy in acute respiratory distress syndrome.

[Methods of burn treatment. Part I: general aspects]

Burns and scalds are common injuries that present with a wide range of severity. Correct evaluation of a burn's depth and extent is essential for adequate treatment, not only initially but also for late results. The depth of a burn is classified as first-to-third degree, and its extent can be deducted from specific tables. As a generalised haemodynamic reaction, a capillary leak allows fluid and colloidal substances to leave the intravasal system. This can lead to hypovolemic shock. In the first 24 h, only cristalloid fluid according to Baxter's formula should be administered. Transfer to a burn centre is indicated in accordance with well-defined guidelines. Concomitant injuries, especially inhalation traumata, need to be diagnosed and treated early. By activation of the immune response, a sepsis-like immune response syndrome can occur,resulting in bacterial translocation and colonisation with high mortality rates.

Is high PEEP low volume ventilation in burn patients beneficial? A retrospective study of 61 patients

In burn care lung damage by inhalation injury is a major cause of mortality in burn patients. In the field of intensive care medicine ventilation strategies to reduce lung injury caused by ventilation are under investigation. The promising results of the application of pressure controlled high PEEP low volume (HPLV) ventilation prompted us to use this ventilation strategy in our burn ICU. To establish whether this ventilation regime is beneficial the charts of 61 consecutive patients needing artificial respiration were reviewed. A scoring system for PEEP level and tidal volume was developed and treatment groups with high PEEP and low volume and low PEEP high volume regimes were compared. No statistically significant differences could be found when comparing treatment versus mortality, the number of pulmonary complications or incidence of pneumothoraces. However, the trend showed a benefit in mortality for patients with an ABSI scoring up to 9, but at the same time pulmonary complications increase. The Horovitz oxygenation index showed no advantage for the HPLV Group. In a separate analysis we found a significant correlation between absolute PEEP and mortality. The correlation between PEEP level and mortality is a dynamic factor predicting outcome, This not been described yet and can be an addition to the static ABSI score. Differences between ventilation strategies were not as evident as expected in this retrospective study, so prospective randomized studies are needed.

Inhalation injury in the burn patient

Patients who survive to hospital admission after bums with inhalation injury face a difficult and potentially prolonged course of treatment in the burn center. Continuing survival and especially functional outcome hinges on the patient's receiving comprehensive, well-coordinated care from an interdisciplinary team of skilled health care providers. The best care plan combines close monitoring of vital organ/tissue perfusion indicators, aggressive management of pulmonary compromise, and scrupulous attention to all details of nursing care. Many patients suffer complications from their injuries or treatment, and not all survive. Those who do may face prolonged and painful therapies on the way to recovery. The expert nurse managing and caring for this unfortunate population faces tremendous clinical challenges but also has the opportunity and satisfaction of helping each patient achieve the best possible outcome.

Survival of severe ARDS with five-organ system failure following burns and inhalation injury in a 15-year-old patient

OBJECTIVE

To show the effectiveness of an integrated therapeutical approach in a severe case of acute respiratory distress syndrome (ARDS) following burns, inhalation injury with therapy-refractory oxygenation under maximized ventilatory settings, and an overall complicated clinical course.

PATIENT AND METHODS

Case report of a patient with severe inhalation injury and burns in an intensive care unit setting, undergoing cardiopulmonary resuscitation (CPR), nitric oxide (NO)-inhalation, surfactant-, kinetic-, and urodilatin-therapy.

CASE REPORT

A 15-year-old male presented with deep dermal and full thickness thermal injuries involving 25% of his total body surface area. Shortly after presentation, the patient developed therapy-refractory respiratory failure, cardiac arrest, and subsequently suffered five-organ system failure (lung, heart, gastrointestinal, liver, kidney), in addition to burn injury, and ischemia related cerebral lesions. The patient was successfully treated with cardiac resuscitation, extra corporeal membrane oxygenation (ECMO), NO, kinetic therapy, surfactant, urodilatin, and other standard intensive care regimens. Three months post-trauma the patient was discharged home, nearly fully recovered.

CONCLUSIONS

In a patient with severe ARDS, oxygenation failure under maximized ventilatory settings, and subsequent five-organ system failure, an integrated therapeutical approach comprising ECMO, NO, kinetic therapy, surfactant, and urodilatin did cross-bridge respiratory and vital functions, enabling overall survival.

Pathogenesis and management of respiratory insufficiency following pulmonary resection

The underlying principle of the surgical treatment of non-small-cell lung cancer (NSCLC) is complete removal of the local/regional disease within the thorax. Pulmonary resection should be as conservative as possible without compromising the adequacy of tumor removal. A multitude of factors influence the incidence and severity of complications following pulmonary resection including the pre-operative physical and psychological status of the patient, the pathologic process requiring resection, the physiologic impact of the procedure, and the addition of pre-operative or postoperative adjuvant therapy. The insidious onset of interstitial changes on chest X-ray (CXR) 1 to 2 days after pulmonary resection forewarns of respiratory distress; however, the pathophysiology of adult respiratory distress syndrome (ARDS) with progression to respiratory failure requiring mechanical ventilation and advanced critical care often unfolds. Management of patients with severe respiratory failure remains primarily supportive. "Good critical care" is the mainstay of therapy: this includes gentle mechanical ventilation to avoid ventilator-induced barotrauma and over-extension of remaining functional alveoli, diuresis, infection identification and management, and nutritional support. New therapeutic strategies that may impact on outcomes in the adult population include pressure-limited ventilation (permissive hypercapnia), inverse ratio ventilation, high-frequency jet ventilation, high-frequency oscillatory ventilation, intratracheal pulmonary ventilation, and prone position ventilation. In addition, alternative therapies such as partial liquid ventilation, inhaled nitric oxide, and extracorporeal techniques including extracorporeal membrane oxygenation (ECMO), extracorporeal carbon dioxide removal (ECCO(2)R), intravascular oxygenation (IVOX), and arteriovenous carbon dioxide removal (AVCO(2)R), provide additional modalities. A component of some or all of these strategies is finding a role in clinical practice.