Necrotizing Tracheobronchitis Research Articles

Clinical presentations and diagnostic approaches of pediatric necrotizing tracheobronchitis with influenza A virus and Staphylococcus aureus co-infections

In March 2023, our pediatric intensive care unit (PICU) retrospectively examined six cases of pediatric necrotizing tracheobronchitis (NTB), focusing on co-infections with influenza A virus (IAV) and Staphylococcus aureus (S. aureus). This study aimed to elucidate NTB’s clinical characteristics, diagnostics, and therapeutic approaches. Diagnostics included symptom assessment, microbiological testing that confirmed all patients were positive for IAV H1N1 with a predominant S. aureus co-infection, and bronchoscopy. The patients predominantly exhibited fever, cough, and dyspnea. Laboratory analysis revealed decreased lymphocyte counts and elevated infection markers like C-reactive protein and procalcitonin. Chest computed tomography (CT) scans detected tracheobronchial obstructions in half of the cases, while bronchoscopy showed severe mucosal congestion, edema, necrosis, and purulent-hemorrhagic exudates. Treatments encompassed comprehensive strategies like oxygen therapy, intubation, bronchoscopic interventions, thoracentesis, oseltamivir, and a regimen of antibiotics. Our findings suggested potential correlations between clinical markers, notably lymphocyte count and procalcitonin, and clinical interventions such as the number of rescues and intensive care unit (ICU) duration. This research highlights the importance of early detection and the role of bronchoscopy and specific markers in assessing NTB, advocating for continued research in larger cohorts to better understand its clinical trajectory and refine treatment approaches for this challenging pediatric disease.

Necrotizing Tracheobronchitis as a Complication of High Frequency Oscillatory Ventilation

INTRODUCTION: High-frequency oscillatory ventilation (HFOV) is an alternative mode of ventilatory support for patients with severe adult respiratory distress syndrome (ARDS) failing conventional ventilation. Reported complications include pneumothorax, pneumomediastinum, and subcutaneous emphysema. While necrotizing tracheobronchitis (NTB) has been widely reported in the pediatric literature with a reported incidence between 4–44%, it is rare in adults. We report a case of NTB associated with HFOV.

Necrotizing tracheobronchitis in an infant

To alert the pediatric emergency physician about an unusual cause of airways obstruction in children undergoing mechanical ventilation. We report a case of necrotizing tracheobronchitis (NTB) in an 8-month-old boy and discuss the pathophysiology, diagnosis and treatment of this disease. This child presented a good outcome that was related to prompt diagnosis and treatment with bronchoscopic removal of necrotic tissue. The pediatric emergency physician must consider NTB in every children undergoing mechanical ventilation who presents acute episodes of airways obstruction, hypercarbia, lack of chest movement and pulmonary hyperinflation, even out of the perinatal period. This characteristic clinical presentation, when recognized, is an indication for emergency tracheobronchoscopy.

Acute Airway Obstruction and Necrotizing Tracheobronchitis From Invasive Mycosis

Necrotizing tracheobronchitis and acute airway obstruction from invasive mycosis developed in a patient who had undergone bone marrow transplantation. The infectious process obstructed the airway and disintegrated the walls of the right mainstem bronchus and pulmonary artery. The airway was cleared using rigid bronchoscopy to extract the detritus. The patient died of hemorrhage after rupture of the pulmonary artery through the right mainstem bronchus.

Overwhelming Necrotizing Tracheobronchitis due to Inadequate Humidification during High-Frequency Jet Ventilation

Necrotizing tracheobronchitis (NT) associated with conventional mechanical ventilation or high-frequency jet ventilation (HFJV) is a lesion reported most often in neonates. In most cases, a specific cause is not identified. We describe a case of NT in an adult that occurred during HFJV and was attributable to inadequate humidification.

Necrotizing Tracheobronchitis (NTB) Following High Frequency Ventilation: Role of an Angiotensin Converting Enzyme Inhibitor

The purpose of this investigation was to study the effect of an angiotensin converting enzyme inhibitor (enalaprilat) on the morphologic manifestations of experimentally induced necrotizing tracheobronchitis (NTB). Twenty piglets were anesthetized before saline lung lavage. High frequency flow interrupter (HFFI) ventilation was used with a strategy known to produce NTB. Animals were randomly assigned to receive IV enalaprilat 0.1 mg/kg (ENP-Hi), enalaprilat 0.01 mg/kg (ENP-Lo), or saline (C). After 8 hours of ventilation, the piglets were sacrificed. Total airway injury scores (mean +/- S.D.) were 1.2 +/- 0.7 for ENP-Hi, 0.2 +/- 0.2 for ENP-Lo, and 21.3 +/- 16 for group C. Enalaprilat minimizes NTB lesions in neonatal piglets exposed to high frequency oscillatory ventilation. Although the origin of NTB is multifactorial, airway mucosa ischemia may play an important role. Enalaprilat may compensate for the reduction of mucosal blood flow by limiting formation of angiotensin II and/or preventing degradation of bradykinin.

Necrotizing Tracheobronchitis Following High Frequency Ventilation: Effect of Hydrocortisone

A piglet model of acute respiratory failure was used to determine whether necrotizing tracheobronchitis (NTB) produced during high-frequency pneumatic flow interrupter (HFFI) ventilation could be attenuated by prior administration of 2 mg/kg hydrocortisone IV. Fourteen piglets (means age 3.6 days, means wt 1.4 kg) were anesthetized and paralyzed before saline lung lavage. The animals were randomly assigned to either placebo (P) or hydrocortisone (H) group. Continuous HFFI (10 Hz) was interrupted five times per minute by a 1-second deflationary pause. All animals were kept on 1.0 FI02 with ventilators adjusted to maintain adequate arterial blood gases. Airway pressures were similar for both groups. After 8 hours of ventilation the animals were sacrificed and their lungs inflated with formalin to 40 cm H2O. Sections were obtained from trachea, carina, main stem, and peripheral bronchi. A total airway injury (TAIS) was calculated by a pathologist unaware of treatment assignment. There was a significant difference (p less than 0.01, Wilcoxon rank sum) in TAIS scores between P (means 21.3) and H (means 7.8). In five out of seven P animals and in one out of seven H animals, NTB was severe and extended to the hilar bronchi. Although NTB is multifactorial in origin, the prior use of hydrocortisone may decrease the severity and extent of lesions by modifying the inflammatory response to this specific airway injury.

Diffuse necrotizing tracheobronchitis: An acute and chronic disease

Necrotizing tracheobronchitis (NTB) is characterized by acute episodes of airway obstruction, hypercarbia, and lack of chest movement in mechanically ventilated neonates. Emergency bronchoscopic removal of necrotic tissue is essential for survival. Although postmortem lesions extend into smaller bronchi, survivors have not demonstrated residual tracheobronchial abnormalities. Two infants were treated successfully for NTB but succumbed to diffuse tracheobronchial strictures with progressive pulmonary hyperinflation. A third neonate with esophageal atresia and left pulmonary agenesis developed NTB. Despite initial postbronchoscopic improvement, the infant died at age 6 weeks with diffuse obstructing NTB. All three infants required endotracheal intubation and mechanical ventilation. High-frequency jet ventilation was not used. Tracheal cultures for fungi, bacteria and viruses were negative. Successful treatment of NTB may be followed acutely by recurrence of NTB and chronically by diffuse tracheobronchial strictures and emphysema.

Necrotizing Tracheobronchitis Following High-Frequency Ventilation: Effect of Lung Deflation

A piglet model of acute respiratory failure was used to determine whether necrotizing tracheobronchitis (NTB) reported during high-frequency pneumatic flow interrupter (HFFI) ventilation could be minimized by a different ventilatory strategy. Twenty-one piglets (mean age 3.8 days, average weight 1.4 kg) were anesthetized with ketamine and given Pavulon prior to saline lung lavage. Femoral vessels were cannulated for measurements of blood pressures, arterial blood gases (ABG), and fluid administration. Airway pressures were measured 5 mm above the endotracheal tube tip. To allow for lung deflation, HFFI (10 Hz) was programmed to pause for 1 sec either 5 (HFFI5) or 12 times per min (HFFI12). Seven animals were assigned to each of the treatment groups and to a conventional mechanical ventilation (CMV) control. All animals were kept on 1.0 FIO2 with ventilators adjusted to maintain ABG (pO2 = 50-100 mmHg and pCO2 = 30-40 mmHg). After 6 h of ventilation, the animals were sacrificed and their lungs inflated with formalin to 40 cm H2O. Sections were obtained from trachea, carina, mainstem, and hilar bronchi. An airway injury score (AIS) was calculated after "blinded" microscopic evaluation. There was no difference in total AIS between CMV (2.4) and HFFI12 (8.6) but a statistically significant difference (p less than 0.05) existed between CMV and HFFI5 (14.1). NTB was limited to the trachea during HFFI12 but extended down to the hilar bronchi during HFFI5. More frequent lung deflations reduce the severity and distribution of NTB during HFFI ventilation.

Diagnosis and therapy of necrotizing tracheobronchitis in ventilated neonates.

From January 1983 to September 1984 our neonatal ICU (NICU) treated eight endotracheally intubated infants who had suspected airway obstruction characterized by hypercarbia dissonant with severity of lung disease and difficulty in ventilation with lack of chest movement, both on conventional intermittent mandatory ventilation and high-frequency oscillation. Bronchoscopic removal of necrotic tissue was possible in six infants, two of whom survived. Bronchoscopy showed desquamation of epithelial surfaces, leaving encrusted exudations considered to be characteristic of necrotizing tracheobronchitis (NTB). The four nonsurvivors of bronchoscopy and one of the infants not submitted to bronchoscopy had NTB confirmed at autopsy. NTB was not associated with any specific lung disease, humidifier, or ventilator. The autopsy frequency of NTB during this period was 5 per 160 NICU admissions. A separate chart review of unselected autopsied cases in 1981 and 1982 showed that 12 of 284 neonates admitted to the NICU had NTB. NTB appears to be a rediscovered condition related to endotracheal intubation and mechanical ventilation using high mean airway pressures.

Necrotizing tracheobronchitis: A new indication for emergency bronchoscopy in the neonate

Necrotizing tracheobronchitis (NTB) is a recently recognized cause of tracheal obstruction in the mechanically ventilated neonate. This process involves inflammation and necrosis of the mucosa of the distal trachea and mainstem bronchi. The sloughing of this material into the tracheal lumen results in plugging and acute respiratory distress. We documented this diagnosis in 19 infants. Four were diagnosed at autopsy. Fifteen had emergency bronchoscopy performed in the neonatal intensive care unit with removal of the obstructing debris. Ten of these 15 neonates survived (66.7%). The diagnosis of necrotizing tracheobronchitis should be suspected in those neonates requiring positive pressure ventilation in whom a sudden unexplained increase in ventilatory requirements develops. This is often associated with hypercarbia and a history of high-peak inspiratory pressures with or without hypoxia. Emergency bronchoscopy in these neonates is necessary both for diagnosis and treatment of the necrotizing tracheobronchitis.