Background

Tracheostomy is a common procedure performed in human ICU for long-term mechanical ventilation (MV); in veterinary medicine, limited information about its use and complications is currently available. A tracheostomy tube is an indwelling device that represents a potential surface for bacterial colonization.

Acinetobacter baumannii is a gram-negative, ubiquitous, opportunistic and biofilm-forming bacteria; this latter characteristic makes it able to colonize medical devices, which promotes the development of multi-drug resistance (MDR). It is one of the major pathogens responsible for nosocomial infections in critically ill human patients, where it most commonly colonizes the respiratory tract.

Case Presentation

A 9-year-old, female Great Dane (BW 65 kg) was presented after a one-week history of hyperthermia and increased respiratory effort. The dog was already on broad-spectrum antibiotic therapy. Due to progressive worsening of respiratory condition (PaO₂ 32 mm Hg; P/F 1.06) MV was elected. A thoracic CT scan detected a severe bronchoalveolar pattern and an MDR Klebsiella pneumoniae was isolated from urine, blood and bronchoalveolar lavage culture. According to the antibiogram, amikacin was administered at 20 mg/kg SID. To optimize management in a large-breed dog who requires prolonged MV, an early tracheostomy (day 2) was performed. After an initial improvement, from day 7 the dog became progressively hyperthermic, hemodynamically unstable, with worsening pulmonary function and significant increase in tracheobronchial secretions. Suspecting a ventilator-associated pneumonia, a tracheal aspirate and blood culture were performed and A. baumannii imipenem-sensitive was isolated in both. Due to progressive worsening of clinical condition the dog was euthanized after 10 days of MV.

New Unique Information

In human medicine nosocomial A. baumannii infection is well described in tracheostomized patients. To the authors’ knowledge, this is the first description of an MDR A. baumannii infection in a tracheostomized dog that underwent long-term MV. The use of different antibiotics and the presence of indwelling devices predispose to select MDR bacteria. In veterinary patients, the use of last-line antibiotics (e.g., carbapenems) poses ethical issues that often result in euthanasia. Because veterinary guidelines are lacking, this case underlines how the rational use of antibiotics and appropriate hygienic measures are important during the management of tracheostomized patients.

E-mail: angelica.botto.ab@gmail.com