Acute Lung Injury and Acute Respiratory Distress Syndrome in Cats: 65 Cases (1993–2003)

Abstract

Objectives: 1) Describe the clinical course and diagnostic findings of cats with histopathologic evidence of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). 2) Identify risk factors for ALI/ARDS in cats. Animals: Sixty‐five client‐owned cats with moderate to severe interstitial pneumonia, pneumonitis or alveolitis consistent with ALI/ARDS on post‐mortem examination and clinical evidence of respiratory compromise. Procedure: Retrospective evaluation of medical records, postmortem examination and radiographs. Results: Cats in this study tended to be middle aged (mean 6.5±4.9 years). They had a short duration of illness (median 4 days; range 0–120 days) and of dyspnea (median 1 day; range 1–7 days). On presentation, the cats were tachypneic (mean respiratory rate 53±23 bpm) and relatively bradycardic (mean heart rate 166±43 bpm). The majority of cats were dyspneic (n=39) at presentation; all others developed respiratory difficulties during hospitalization. The mean white blood cell count was within normal limits (14.6±14.0 k/μL); 8 cats had a leukocytosis and 7 were leucopenic. Clinical findings consistent with SIRS (n=39) and sepsis (n=10) were common. Thoracic radiographs were reviewed in 31 cats and alveolar disease was the most frequent pattern (105 lung lobes) followed by interstitial disease (86 lung lobes). No cat had normal thoracic radiographs throughout hospitalization. Underlying disease was not identified on post‐mortem examination in 15 cats (23%), but in the remaining cats underlying diseases included infectious systemic disease (n=11), neoplasia (n=8), respiratory (n=8) and urinary (n=7) system disorders, acute pancreatitis (n=7), hepatic diseases (n=5), major trauma (n=4), sepsis (n=3), CNS (n=2) and other systems (n=5). Nine cats had more then one underlying process. Conclusions: This study describes a naturally‐occurring syndrome of ALI/ARDS in cats analogous to that which occurs in dogs and humans. In cats, ALI/ARDS occurs as a sequela of a variety of underlying systemic diseases, but in approximately one‐quarter of patients an underlying cause is not identified at necropsy. It is important to consider ALI/ARDS in systemically ill cats who become dyspneic; in cats with pulmonary disease with acute worsening of respiratory status and in cats with pulmonary infiltrates for which no other cause can be identified.

Postoperative pulmonary complications in dogs undergoing laparotomy: frequency, characterization and disease‐related risk factors

“…In many cases, their disease was severe enough to preclude arterial blood gas analysis without oxygen supplementation. The final PaO 2 /FiO 2 ratios for dogs in this group prior to death were 245–313 mmHg, which are consistent with the reported clinical criteria for diagnosis of ALI 28,32,36–38 . The ARDS cases typically had a shorter duration of oxygen therapy than those in other categories, however, this was because their disease progressed rapidly and was ultimately fatal.…”

“…Respiratory failure is characterized by lung inflammation, cellular infiltration and recruitment of inflammatory cells, injury to the alveolar basement membrane, and capillary leakage 3,35 . Acute lung injury (ALI) is a term used to describe a similar but less severe pulmonary injury 35,36 . Although originally identified and defined in human patients, it is now recognized that ARDS affects critically ill dogs and cats 32,36,37 .…”

“…Acute lung injury (ALI) is a term used to describe a similar but less severe pulmonary injury 35,36 . Although originally identified and defined in human patients, it is now recognized that ARDS affects critically ill dogs and cats 32,36,37 . In humans, criteria for a clinical diagnosis of ARDS include acute onset of respiratory distress in a susceptible patient, bilateral pulmonary infiltrates, PaO 2 /FiO 2 ≤200, and a pulmonary artery wedge pressure less than or equal to 18 mmHg (absence of cardiac disease) 35 .…”