Treatment of plastic bronchitis by orthotopic heart transplantation

Airway emergency during general anesthesia in a child with plastic bronchitis following Fontan surgery: a case report

Background

Plastic bronchitis (PB) is a complication of Fontan surgery, results in the formation of mucus plug in the tracheobronchial tree, causing potentially fatal airway obstruction. We report critical airway emergency during general anesthesia in a child with plastic bronchitis.

Case presentation

A 5-year-old boy was scheduled for intrapulmonary lymphatic embolization through percutaneous catheterization under general anesthesia. He underwent Fontan surgery at the age of 2 and frequently developed respiratory failure due to plastic bronchitis. After induction of general anesthesia and tracheal intubation, mechanical ventilation became difficult even with an inspiratory pressure ≥ 50 mmHg due to airway obstruction. He expectorated a large mucus plug through the tracheal tube after administration of sugammadex, naloxone, and flumazenil, and respiratory condition was stabilized thereafter.

Conclusion

General anesthesia for a patient with plastic bronchitis should be planned with extracorporeal membrane oxygenation or cardiopulmonary bypass stand by.

Bronchoscopic and histologic findings during lymphatic intervention for plastic bronchitis

BACKGROUND

Percutaneous lymphatic intervention (PCL) is a promising new therapy for plastic bronchitis (PB). We characterized bronchoalveolar lavage (BAL) and cast morphology in surgically repaired congenital heart disease (CHD) patients with PB during PCL. We quantified respiratory and bronchoscopic characteristics and correlated them with post-intervention respiratory outcomes.

METHODS

We retrospectively reviewed patients with PB and surgically repaired CHD undergoing PCL and bronchoscopy at our institution. Pre-intervention characteristics, bronchoscopy notes, BAL cell counts, virology, and cultures were collected. A pathologist blinded to clinical data reviewed cast specimens. Respiratory outcomes were evaluated through standardized telephone questionnaire.

RESULTS

Sixty-two patients were included with a median follow-up of 20 months. No patients experienced airway bleeding, obstruction, or prolonged intubation related to bronchoscopy. Of BAL infectious studies, the positive results were 4 (8%) fungal, 6 (11%) bacterial, and 6 (14%) viral. Median BAL count per 100 cells for neutrophils, lymphocytes, and eosinophils were 13, 10, and 0, respectively. Of 23 bronchial casts analyzed, all contained lymphocytes, and 19 (83%) were proteinaceous, with 14 containing neutrophils and/or eosinophils. Median BAL neutrophil count was greater in patients with proteinaceous neutrophilic or eosinophilic casts compared to casts without neutrophils or lymphocytes (P = 0.030). Post-intervention, there was a significant reduction in respiratory medications and support and casting frequency.

CONCLUSIONS

The predominance of neutrophilic proteinaceous casts and high percentage of positive BAL infectious studies support short-term fibrinolytic and anti-infective therapies in PB in select patients. Flexible bronchoscopy enables safe assessment of cast burden. PCL effectively treats PB and reduces respiratory therapies.

Lymphatic dysfunction in critical illness

PURPOSE OF REVIEW

The essential role of the lymphatic system in fluid homeostasis, nutrient transport, and immune trafficking is well recognized; however, there is limited understanding of the mechanisms that regulate lymphatic function, particularly in the setting of critical illness. The lymphatics likely affect disease severity and progression in every condition, from severe systemic inflammatory states to respiratory failure. Here, we review structural and functional disorders of the lymphatic system, both congenital and acquired, as they relate to care of the pediatric patient in the intensive care setting, including novel areas of research into medical and procedural therapeutic interventions.

RECENT FINDINGS

The mainstay of current therapies for congenital and acquired lymphatic abnormalities has involved nonspecific medical management or surgical procedures to obstruct or divert lymphatic flow. With the development of dynamic contrast-enhanced magnetic resonance lymphangiography, image-directed percutaneous intervention may largely replace surgery. Because of new insights into the mechanisms that regulate lymphatic biology, pharmacologic inhibitors of mTOR and leukotriene B4 signaling are each in Phase II clinical trials to treat abnormal lymphatic structure and function, respectively.

SUMMARY

As our understanding of normal lymphatic biology continues to advance, we will be able to develop novel strategies to support and augment lymphatic function during critical illness and through convalescence.

Echocardiographic characteristics in Fontan patients before the onset of protein-losing enteropathy or plastic bronchitis

BACKGROUND

It was this study's objective to evaluate the echocardiographic characteristics and flow patterns in abdominal arteries of Fontan patients before the onset of protein-losing enteropathy (PLE) or plastic bronchitis (PB).

DESIGN

In this retrospective cohort investigation, we examined 170 Fontan patients from 32 different centers who had undergone echocardiographic and Doppler ultrasound examinations between June 2006 and May 2013. Follow-up questionnaires were completed by 105 patients a median of 5.3 (1.5-8.5) years later to evaluate whether one of the complications had occurred since the examinations.

RESULTS

A total of 91 patients never developed PLE or PB ("non-PLE/PB"); they were compared to 14 affected patients. Eight of the 14 patients had already been diagnosed with "present PLE/PB" when examined. Six "future PLE/PB" patients developed those complications later on and were identified on follow-up. The "future PLE/PB" patients presented significantly slower diastolic flow velocities in the celiac artery (0.1 (0.1-0.5) m/s vs 0.3 (0.1-1.0) m/s (P = .04) and in the superior mesenteric artery (0.0 (0.0-0.2) m/s vs 0.2 (0.0-0.6) m/s, P = .02) than the "non-PLE/PB" group. Median resistance indices in the celiac artery were significantly higher (0.9 (0.8-0.9) m/s vs 0.8 (0.6-0.9) m/s, (P = .01)) even before the onset of PLE or PB.

CONCLUSION

An elevated flow resistance in the celiac artery may prevail in Fontan patients before the clinical manifestation of PLE or PB.

Percutaneous Lymphatic Embolization of Abnormal Pulmonary Lymphatic Flow as Treatment of Plastic Bronchitis in Patients With Congenital Heart Disease

BACKGROUND

Plastic bronchitis is a potentially fatal disorder occurring in children with single-ventricle physiology, and other diseases, as well, such as asthma. In this study, we report findings of abnormal pulmonary lymphatic flow, demonstrated by MRI lymphatic imaging, in patients with plastic bronchitis and percutaneous lymphatic intervention as a treatment for these patients.

METHODS AND RESULTS

This is a retrospective case series of 18 patients with surgically corrected congenital heart disease and plastic bronchitis who presented for lymphatic imaging and intervention. Lymphatic imaging included heavy T2-weighted MRI and dynamic contrast-enhanced magnetic resonance lymphangiogram. All patients underwent bilateral intranodal lymphangiogram, and most patients underwent percutaneous lymphatic intervention. In 16 of 18 patients, MRI or lymphangiogram or both demonstrated retrograde lymphatic flow from the thoracic duct toward lung parenchyma. Intranodal lymphangiogram and thoracic duct catheterization was successful in all patients. Seventeen of 18 patients underwent either lymphatic embolization procedures or thoracic duct stenting with covered stents to exclude retrograde flow into the lungs. One of the 2 patients who did not have retrograde lymphatic flow did not undergo a lymphatic interventional procedure. A total of 15 of 17(88%) patients who underwent an intervention had significant symptomatic improvement at a median follow-up of 315 days (range, 45-770 days). The most common complication observed was nonspecific transient abdominal pain and transient hypotension.

CONCLUSIONS

In this study, we demonstrated abnormal pulmonary lymphatic perfusion in most patients with plastic bronchitis. Interruption of the lymphatic flow resulted in significant improvement of symptoms in these patients and, in some cases, at least temporary resolution of cast formation.

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.

Severe airway obstruction from a bronchial cast after cardiac transplantation

Plastic bronchitis is a rare and difficult to treat disease process in patients with congenital heart disease. Cardiac transplantation has been used increasingly to reverse this process, especially in single ventricle physiology. This case report demonstrates a foreseeable complication after cardiac transplantation in such a patient.

A multifaceted approach to the management of plastic bronchitis after cavopulmonary palliation

BACKGROUND

Plastic bronchitis is a rare, potentially life-threatening complication after Fontan operation. Hemodynamic alterations (elevated central venous pressure and low cardiac output) likely contribute to the formation of tracheobronchial casts composed of inflammatory debris, mucin, and fibrin. Pathologic studies of cast composition support medical treatment with fibrinolytics such as inhaled tissue plasminogen activator (t-PA).

METHODS

This was a retrospective case series of medical, surgical, and catheter-based treatment of patients with plastic bronchitis after cavopulmonary palliation.

RESULTS

Included were 14 patients (86% male, 93% white). Median age at Fontan operation was 2.7 years (range, 1.2 to 4.1 years), with median interval to plastic bronchitis presentation of 1.5 years (range, 9 days to 15.4 years). Cast composition was available for 11 patients (79%) and included fibrin deposits in 7. All patients were treated with pulmonary vasodilators, and 13 (93%) were treated with inhaled t-PA. Hemodynamically significant lesions in the Fontan pathway were addressed by catheter-based (n=9) and surgical (n=3) interventions. Three patients (21%) underwent heart transplantation. Median follow-up was 2.7 years (range, 0.6 to 8.7 years). Symptoms improved, such that 6 of 13 patients (46%) were weaned off t-PA. Rare or episodic casts are successfully managed with outpatient t-PA in most of the other patients. Of the 3 patients who underwent heart transplant, 2 are asymptomatic and 1 has recurrent casts in the setting of elevated filling pressures and rejection.

CONCLUSIONS

A systematic step-wise algorithm that includes optimization of hemodynamics, aggressive pulmonary vasodilation, and inhaled t-PA is an effective treatment strategy for patients with plastic bronchitis after cavopulmonary connection.

End-organ consequences of the Fontan operation: liver fibrosis, protein-losing enteropathy and plastic bronchitis

The Fontan operation, although part of a life-saving surgical strategy, manifests a variety of end-organ complications and unique morbidities that are being recognised with increasing frequency as patients survive into their second and third decades of life and beyond. Liver fibrosis, protein-losing enteropathy and plastic bronchitis are consequences of a complex physiology involving circulatory insufficiency, inflammation and lymphatic derangement. These conditions are manifest in a chronic, indolent state. Management strategies are emerging, which shed some light on the origins of these complications. A better characterisation of the end-organ consequences of the Fontan circulation is necessary, which can then allow for development of specific methods for treatment. Ideally, the goal is to establish systematic strategies that might reduce or eliminate the development of these potentially life-threatening challenges.

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.

Perioperative management of shock in two fontan patients with plastic bronchitis

Plastic bronchitis is potentially a life-threatening complication of long-standing surgically palliated single ventricle congenital heart disease. Patients can present with hypoxia requiring urgent bronchoscopy for removal of bronchial casts. Perioperative care for these patients is challenging and anesthesia is associated with significant cardiac risk. As more surgically corrected single ventricle patients survive to adulthood, these patients are expected to present more frequently. This report details the perioperative management of 2 Fontan patients with hypoxia and significant plastic bronchitis disease burden.

New concepts: development of a survivorship programme for patients with a functionally univentricular heart

Children with functionally univentricular hearts are now surviving into their third and fourth decades of life. Although survival alone is a remarkable achievement, a lot must still be done to improve the quality and duration of life after the Fontan operation. Challenges that may be faced by these patients include the impact of the Fontan operation on the liver and the density of bone, protein-losing enteropathy, and plastic bronchitis. Paediatric cardiologists are familiar with the haemodynamic issues inherent in Fontan physiology; however, training in cardiology is often not sufficient to give us a complete understanding of the pathophysiology of the complications or of the options for treatment. Collaboration with other subspecialists including gastroenterologists, endocrinologists, and pulmonologists is essential in order to provide the rigorous and nuanced care that our patients need and deserve. A clinic in which a patient can see multiple subspecialists, and in which the subspecialists, as a group, can discuss each patient, can provide a unique and valuable service for patients with a functionally univentricular heart.