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Acute Respiratory Distress Syndrome Secondary to an Unusual Infection

Reviewed By Microbiology, Tuberculosis & Pulmonary Infections Assembly

Submitted by

Carmen Luraschi-Monjagatta, M.D.


Division of Pulmonary and Critical Care Medicine

University of Arizona

Tucson, Arizona

Linda Snyder, M.D.

Professor of Medicine

Division of Pulmonary and Critical Care Medicine

University of Arizona

Tucson, Arizona

Submit your comments to the author(s).


A 39 year-old man from Whiteriver, Arizona presented to the Emergency Department with a five-day history of fever, chills, nausea, vomiting, and cough productive of purulent sputum. He had evidence of acute kidney injury and sepsis and was transferred to our hospital for further evaluation. Upon admission to our hospital, he had diffuse abdominal pain with diarrhea, left foot pain, cough and mild dyspnea.

Past medical history is significant for poorly controlled diabetes mellitus, severe peripheral vascular disease with previous toe amputations, hypertension, hyperlipidemia and depression.

Social history is notable for previous alcohol abuse and a 50 pack-year smoking history. He lives on the Apache Indian Reservation and denied recent travel. He denied recreational drug use.

Medications include gabapentin, atenolol, simvastatin, aspirin, glypizide, pioglitazone, sertraline and trazodone. Prior to transfer, he was given clindamycin for presumed pneumonia and sepsis.

Physical Exam

Vital signs revealed a temperature 38.8°C, blood pressure 163/93 mmHg, heart rate 92 beats per minute, respiratory rate 24 breaths per minute, and oxygen saturation 94% on 4L oxygen by nasal cannula. The patient was in moderate respiratory distress. Cardiac examination revealed a regular rate and rhythm without murmurs or gallop. Respiratory examination revealed diffuse inspiratory crackles without wheezing. The abdomen was non-tender and non-distended, without hepatosplenomegaly. Extremities revealed a right leg ulcer without signs of infection, but no clubbing. He had no rash.


Complete blood count showed a white blood cell count of 13,100/ml with 66% neutrophils, 24% basophils, 7% lymphocytes, 3% monocytes, 0% eosinophils, hemoglobin 13 g/dl, hematocrit 36% and platelet count of 85,000/ml.

Comprehensive metabolic panel demonstrated:  sodium 127 mMol/L, potassium 3.2 mMol/L, chloride 98 mMol/L, bicarbonate 19 mMol/L, blood urea nitrogen 26 mg/dl, creatinine 2.7 mg/dl, glucose 192 mg/dl, total protein 6.6 mg/dl, albumin 1.7 g/dl, bilirubin 0.6 mg/dl, AST 71IU/L, ALT 72 IU/L, and alkaline phosphatase of 99 UI/L.

Arterial lactate was 4.3 mmol/L (normal lactate: < 2 mmol/L) and C-reactive protein (CRP) was 21.9 mg/dl (normal CRP: < 1mg/dl).

Radiographic Studies


Figure 1: Chest radiograph on admission to our hospital

Hospital course

The patient was treated for sepsis and severe community acquired pneumonia with empiric piperacillin- tazobactam and vancomycin. Over the next two days, the patient’s respiratory status worsened and he required intubation and mechanical ventilation. Chest radiographs showed bilateral diffuse pulmonary infiltrates consistent with acute respiratory distress syndrome (ARDS) (Figure 2). Bronchoscopy with bronchoalveolar lavage revealed no evidence of alveolar hemorrhage, cell count with 65% neutrophils, 26% lymphocytes and 9% macrophages and cytology and all cultures were unrevealing. HIV serology was negative. Legionella urinary antigen was negative. The subsequent physical examination showed a petechial rash on the lower extremities.


Figure 2: Chest radiograph in the Intensive Care Unit

Question 1

Which of the following diagnostic tests would be most helpful to secure the final diagnosis?


  1. Chapman AS, Bakken JS, Folk SM, Paddock CD, Bloch KC, Krusell A, Sexton DJ, Buckingham SC, Marshall GS, Storch GA, Dasch GA, McQuiston JH, Swerdlow DL, Dumler SJ, Nicholson WL, Walker DH, Eremeeva ME, Ohl CA; Tickborne Rickettsial Diseases Working Group; CDC. Diagnosis and Management of Tickborne Rickettsial Diseases: Rocky Mountain spotted fever, Ehrlichioses, and Anaplasmosis--United States: A practical guide for physicians and other health-care and public health professionals. MMWR Recomm Rep. 2006 Mar 31; 55(RR-4): 1-27.
  2. Dantas-Torres F. Rocky Mountain spotted fever. Lancet Infect Dis. 2007; 7(11): 724-32.
  3. Demma LJ, Traeger MS, Nicholson WL, Paddock CD, Blau DM, Eremeeva ME, Dasch GA, Levin ML, Singleton J Jr, Zaki SR, Cheek JE, Swerdlow DL, McQuiston JH. Rocky Mountain spotted fever from an unexpected tick vector in Arizona. N Engl J Med. 2005; 353(6): 587-94.
  4. Gonçalves da Costa PS, Brigatte ME, Pereira de Almeida E, de Carvalho Valle LM. Atypical fulminant Rickettsia rickettsii infection (Brazilian spotted fever) presenting as septic shock and adult respiratory distress syndrome. Braz J Infect Dis. 2002; 6(2) :91-6.
  5. Memis D, Sapolya O, Tasdogan M, Yucel T, Vatan I. Rickettsia ricketsii infection presenting as septic shock and adult respiratory distress syndrome. Journal of Chinese Clinical Medicine. 2007,6: Vol 2 (6).
  6. Walker DH, Crawford CG, Cain BG. Rickettsial infection of the pulmonary microcirculation: the basis for interstitial pneumonitis in Rocky Mountain spotted fever. Hum Pathol. 1980; 11 (3): 263-72.
  7. Chen LF, Sexton DJ. What's new in Rocky Mountain spotted fever? Infect Dis Clin North Am. 2008; 22(3): 415-32, vii-viii.
  8. Sahni SK, Rydkina E. Host-cell interactions with pathogenic Rickettsia species. Future Microbiol. 2009; 4(3): 323-39.
  9. Walker DH, Valbuena GA, Olano JP. Pathogenic mechanisms of diseases caused by Rickettsia. Ann N Y Acad Sci. 2003; 990: 1-11.