View Abstract

A3606 - Achromobacter Denitrificans - A Rare Cause of Pneumonia
Author Block: A. A. Albalbissi1, J. Treece2, A. Alazzeh3, S. Arif2, L. A. McKinney-Smith4; 1Division of Internal Medicine, East Tennessee State University, Johnson City, TN, United States, 2Division of Internal Medicine, East Tennessee State University, Johnson city, TN, United States, 3Division of Pulmonology/Critical Care, East Tennessee State University, Johnson city, TN, United States, 4Division of Pulmonary and Critical Care Medicine, James H. Quillen Veteran Affair Medical Center, Mountain Home, Johnson city, TN, United States.
INTRODUCTION:
Pneumonia is a major cause of morbidity, so identifying the causative agent facilitates optimal management and better patient outcomes. We present a case of pneumonia caused by a rare bacterium, Achromobacter denitrificans.
CASE DESCRIPTION:
A 76-year-old male with a past medical history of chronic obstructive lung disease, atrial fibrillation, and Stage IIIa small cell lung cancer was initially treated with a cycle of etoposide and cisplatin but developed acute renal insufficiency, atrial fibrillation, Escherichia coli bacteremia, pneumonia, cytomegalovirus esophagitis, and retinitis, which all eventually resolved. The patient’s chemotherapy regimen was restarted with etoposide and a reduced dose of cisplatin as well as Neupogen support for neutropenia. Although he completed three more cycles of chemotherapy, cisplatin had to be switched to carboplatin in the fourth cycle secondary to worsening kidney function. A few days after the patient’s last chemotherapy cycle, he was exposed to multiple sick contacts while at a funeral, and the patient developed weakness as well as a fever with hypotension and somnolence. He was admitted for neutropenic fever that rapidly progressed to septic shock. Aggressive fluid resuscitation was initiated and multiple vasopressors were started as well as vancomycin and piperacillin/tazobactam. The patient developed pulmonary edema, lung infiltrates, and atrial fibrillation with rapid ventricular response, so he was started on diltiazem drip for rate control with gentle diuresis. A chest x-ray showed prominent interstitial markings with patchy areas of consolidation. A bronchoscopy with bronchial washings was performed due to progressive lung infiltrates despite use of broad-spectrum antibiotics. Bronchial lavage cultures grew Achromobacter denitrificans, so he was switched from vancomycin and piperacillin/tazobactam to meropenem. The patient required intubation secondary to acute hypoxic respiratory failure, and vasopressors were restarted due to hypotension. Diltiazem was replaced by amiodarone to mitigate hypotension. The patient continued to have hypotension, rapid ventricular response, and respiratory distress. Multiple attempts of ventilator weaning were unsuccessful. A second bronchoscopy was performed to reevaluate the pneumonia and thick respiratory secretions. Cultures showed resolution of Achromobacter denitrificans, but Pseudomonas aeruginosa was present. The family then decided to withdraw care per patient’s wishes, and the patient expired.
DISCUSSION: There has been very few reported cases of pneumonia due to Achromobacter denitrificans. These reported cases emphasize the importance of identifying risk factors and prevention methods of Achromobacter denitrificans infection, especially in the setting of immunosuppression.