Successful treatment of severe asthma-associated plastic bronchitis with extracorporeal membrane oxygenation

Fibrin airway cast obstruction: Experience, classification, and treatment guideline from Denver

BACKGROUND AND OBJECTIVES

Plastic bronchitis (PB) is a condition characterized by the formation of thick airway casts leading to acute and often life-threatening airway obstruction. PB occurs mainly in pediatric patients with congenital heart disease (CHO) who have undergone staged surgical palliation (Glenn, Fontan), but can also occur after chemical inhalation, H1N1, severe COVID-19, sickle cell disease, severe asthma, and other diseases. Mortality risk from PB can be up to 40%-60%, and no treatment guideline exist. The objectives herein are to develop a standardized evaluation, classification, and treatment guideline for PB patients presenting with tracheobronchial casts, based on our experience with PB at the Children's Hospital of Colorado in Denver.

METHODS

We describe 11 patients with CHO-associated PB (post-Fontan [n = 9], pre-Fontan [n = 2]) who presented with their initial episodes. We utilized histopathological analysis of tracheobronchial casts to guide treatment in these patients, utilizing our hospital-wide guideline document and classification system.

RESULTS

We found that 100% of post-Fontan PB patients had fibrinous airway casts, while pre-Fontan PB casts were fibrinous only in one of two patients (50%). Utilizing histopathology as a guide to therapy, PB patients with fibrin airway casts were treated with airway-delivered fibrinolytics and anticoagulants, as well as aggressive airway clearance and other supportive care measures. These therapies resulted in successful cast resolution and improved survival in post-Fontan PB patients.

CONCLUSION

We have shown an improved outcome in PB patients whose treatment plan was based on Denver's PB classification schema and standardized treatment guideline based on tracheobronchial cast histopathology.

Extracorporeal membrane oxygenation for near fatal asthma with sudden cardiac arrest

INTRODUCTION

Near fatal asthma is a life-threatening disorder that requires mechanical ventilation. Near fatal asthma and COPD with sudden cardiac arrest can worsen the outcomes. Previous studies demonstrated that ECMO is a live-saving measure for near fatal asthma that does not respond to traditional treatment.

CASE STUDY

A patient with near fatal asthma (NFA) and COPD presented with high airway resistance, life-threatening acidemia and severe hypoxemia that failed to respond to conventional therapy. His hospital course was complicated by sudden cardiac arrest when preparing to initiate V-V mode extracorporeal membrane oxygenation (ECMO). The mode immediately changed from V-V to V-A, then to V-AV and finally to V-V mode in order to improve cardiac function and promote recovery of lung function.

RESULTS

On the sixth day, ECMO was removed and on the ninth day, he was extubated and transferred to the ward. Finally, the patient was discharged home on the nineteenth day after admission to be followed up in the pulmonary clinic.

CONCLUSIONS

The early application of ECMO and mode changing plausibly resulted in dramatic improvement in gas exchange and restoration of cardiac function. This case illustrates the critical role of ECMO mode changing as salvage therapy in NFA and COPD with sudden cardiac arrest.

Extracorporeal Membrane Oxygenation in ARDS

Extracorporeal membrane oxygenation (ECMO) has become a key tool in the management of cardiac and/or respiratory failure refractory to conventional management. Although ECMO has multiple indications, it has been widely studied for the management of acute respiratory distress syndrome in adults. ECMO provides rest and support while the damaged lungs heal. It is an invasive modality with risks of serious complications; therefore, clinicians should be vigilant during patient selection. Furthermore, users should be familiar with different components of the ECMO machinery and the management of different organ systems while patients are on the circuit. ECMO is a relatively new modality that has shown good results when used in certain circumstance, and its use is becoming more popular across the United States.

Plastic Bronchitis in an AIDS Patient with Pulmonary Kaposi Sarcoma

Plastic bronchitis is the expectoration of bronchial casts in the mold of the tracheobronchial tree. It is a rare occurrence of unknown etiology that has been primarily described in children with congenital heart disease. In this case report, we present the first reported case of plastic bronchitis in a patient with pulmonary Kaposi sarcoma and underlying HIV infection.

Adjunctive extracorporeal carbon dioxide removal in refractory status asthmaticus

Status asthmaticus (SA) is a life-threatening disorder. Severe respiratory failure may require extracorporeal membrane oxygenation (ECMO). Previous reports have demonstrated utility of ECMO in SA in various patients with varying success. A 25-year-old man was admitted with status asthmatics and severe hypercapnic respiratory failure. Despite tailored ventilator therapies, such as pressure control ventilation and maximal pharmacological therapy, including general anaesthesia, the patient’s condition deteriorated rapidly. Veno-venous ECMO (VV-ECMO) was provided for respiratory support. The patient’s clinical condition improved over the following 72 hours and was discharged from the intensive care unit on day 3. This case report demonstrates the successful use of VV-ECMO in a patient with severe respiratory failure due to SA, who failed to respond to maximal therapy. This case adds support to a growing body of literature that shows that ECMO can be used with success for refractory status asthmaticus.

Use of serial rigid bronchoscopy in the treatment of plastic bronchitis in children

AIM

Plastic bronchitis (PB) is a rare disorder characterized by formation of bronchial casts (BC) in the tracheobronchial tree with partial or complete airway obstruction. Although lysis of casts with several fibrinolytic agents has been reported, removal of BC with bronchoscope provides better clearance of airways. A retrospective study was performed to evaluate the use of serial rigid bronchoscopy (RB) in the treatment of PB in children.

PATIENTS AND METHODS

Between 2011 and 2015, children with partial or complete airway obstruction with PB were evaluated for age, gender, underlying disease, clinical findings, results of bronchoscopic interventions and histopathologic findings.

RESULTS

Five patients with 14 RB interventions were evaluated. The mean age of the patients was 7.8years (min: 3years - max: 14years) and male-female ratio was 4:1. All of the patients were diagnosed as asthma and none of them had underlying cardiac disease. Suction of mucus plaques and bronchoalveolar lavage were performed in all patients with flexible bronchoscopy. Also, aerosolized tissue plasminogen activator was used in two patients. During follow-up serial RB was indicated in patients with persistent atelectasis and severe airway obstruction. The most common localization of BC was left main stem bronchus and bilateral cast formation was detected in 7 interventions. Although, removal of BC was challenging in two patients because of cast friability and fragmentation, most of the plugs were successfully removed with optical forceps and rigid suctioning. Two patients underwent repeated RB (min: 3 - max: 8) for recurrent symptoms. Histopathologic evaluation of BC revealed Charcot-Leyden crystals with inflammatory cells in all patients. The time interval between RB interventions was one to five months.

CONCLUSION

BC are tenacious mucus plugs which are firmly wedged to the tracheobronchial tree. The use of optical forceps with rigid suction provides adequate removal of BC during RB. Because of underlying disease, it is difficult to cure cast formation. Therefore, most of the patients require serial RB when they become unresponsive to standard therapy or develop partial or complete airway obstruction.

The use of life-saving extracorporeal membrane oxygenation (ECMO) for pregnant woman with status asthmaticus

INTRODUCTION

Status asthmaticus can develop into a life-threatening disorder that requires mechanical ventilation. Severe respiratory failure during pregnancy can worsen maternal and fetal outcomes. Previous case studies have demonstrated extracorporeal membrane oxygenation (ECMO) as a life-saving measure for pregnant women with acute respiratory distress syndrome (ARDS) as well as non-pregnant patients with status asthmaticus.

CASE STUDY

A 25-year-old woman, who was 5 weeks pregnant, was admitted with status asthmaticus and severe hypercapnic respiratory failure. Despite rescue therapies such as pressure control ventilation with high inspiratory pressures, inhaled beta2 agonists and antimuscarinic drugs, intravenous salbutamol, methylprednisolone and magnesium sulfate, her condition gradually deteriorated. Veno-venous ECMO was initiated for respiratory support and the patient's clinical condition as well as the gas exchange improved within the next few days. ECMO was removed and the patient was extubated after 2 days. Sonography, however, revealed a retrochorial hematoma; the patient was diagnosed with abortus imminens and successfully treated with magnesium substitution and bed rest. Finally, she gave birth to a healthy boy at 38 weeks of gestation.

CONCLUSIONS

This is the first case report on the successful use of ECMO in a pregnant woman with severe respiratory insufficiency due to status asthmaticus, who failed to respond to invasive mechanical ventilation and maximum pharmacological treatment. Despite this life-threatening condition, the use of ECMO in our patient has greatly improved the chance of survival for the mother and the baby, who was born without any complications.

Mechanical ventilation for severe asthma

Acute exacerbations of asthma can lead to respiratory failure requiring ventilatory assistance. Noninvasive ventilation may prevent the need for endotracheal intubation in selected patients. For patients who are intubated and undergo mechanical ventilation, a strategy that prioritizes avoidance of ventilator-related complications over correction of hypercapnia was first proposed 30 years ago and has become the preferred approach. Excessive pulmonary hyperinflation is a major cause of hypotension and barotrauma. An appreciation of the key determinants of hyperinflation is essential to rational ventilator management. Standard therapy for patients with asthma undergoing mechanical ventilation consists of inhaled bronchodilators, corticosteroids, and drugs used to facilitate controlled hypoventilation. Nonconventional interventions such as heliox, general anesthesia, bronchoscopy, and extracorporeal life support have also been advocated for patients with fulminant asthma but are rarely necessary. Immediate mortality for patients who are mechanically ventilated for acute severe asthma is very low and is often associated with out-of-hospital cardiorespiratory arrest before intubation. However, patients who have been intubated for severe asthma are at increased risk for death from subsequent exacerbations and must be managed accordingly in the outpatient setting.

Plastic bronchitis arising from solitary influenza B infection: A report of two cases in children

Plastic bronchitis (PB) is characterized by thick, inspissated, tracheobronchial casts. It is classified as either inflammatory or acellular based on the content of the endobronchial casts. PB has never been reported in a healthy child with solitary influenza B infection. This study is a retrospective case series of two children who presented to our institution in acute respiratory distress. Emergency rigid bronchoscopy was performed with extraction of casts from the L mainstem bronchus in both patients. Influenza B was the only isolate identified. In otherwise healthy children with respiratory distress, influenza B-mediated inflammatory PB must be considered in the differential diagnosis.

Tissue plasminogen activator prevents mortality from sulfur mustard analog-induced airway obstruction

Sulfur mustard (SM) inhalation causes the rare but life-threatening disorder of plastic bronchitis, characterized by bronchial cast formation, resulting in severe airway obstruction that can lead to respiratory failure and death. Mortality in those requiring intubation is greater than 80%. To date, no antidote exists for SM toxicity. In addition, therapies for plastic bronchitis are solely anecdotal, due to lack of systematic research available to assess drug efficacy in improving mortality and/or morbidity. Adult rats exposed to SM analog were treated with intratracheal tissue plasminogen activator (tPA) (0.15-0.7 mg/kg, 5.5 and 6.5 h), compared with controls (no treatment, isoflurane, and placebo). Respiratory distress and pulse oximetry were assessed (for 12 or 48 h), and arterial blood gases were obtained at study termination (12 h). Microdissection of fixed lungs was done to assess airway obstruction by casts. Optimal intratracheal tPA treatment (0.7 mg/kg) completely eliminated mortality (0% at 48 h), and greatly improved morbidity in this nearly uniformly fatal disease model (90-100% mortality at 48 h). tPA normalized plastic bronchitis-associated hypoxemia, hypercarbia, and lactic acidosis, and improved respiratory distress (i.e., clinical scores) while decreasing airway fibrin casts. Intratracheal tPA diminished airway-obstructive fibrin-containing casts while improving clinical respiratory distress, pulmonary gas exchange, tissue oxygenation, and oxygen utilization in our model of severe chemically induced plastic bronchitis. Most importantly, mortality, which was associated with hypoxemia and clinical respiratory distress, was eliminated.