Table 1 Clinical characteristics of patients with atypical pneumonia at ICU admission and outcome according to the causative agent

Demographics

 Age

56 [44–67]

54 [41–69]

64 [52–75]

 Female gender

33 (32%)

26 (34%)

7 (25%)

Comorbidities

 Chronic respiratory disease

32 (31%)

22 (29%)

10 (36%)

 Current smoker

30 (29%)

20 (38%)

10 (36%)

 Immunosuppression

21 (20%)

17 (22%)

4 (14%)

 HIV infection

2 (2%)

2 (3%)

0

 Hematological malignancy

10 (10%)

9 (12%)

1 (3.5%)

 Cancer

7 (7%)

4 (5%)

3 (11%)

 Hypertension

32 (31%)

24 (32%)

8 (28%)

Reason for ICU admission

 Acute respiratory distress

96 (92%)

70 (92%)

26 (93%)

 Cardiovascular failure

2 (2%)

2 (3%)

0

 Neurological disorders

3 3%)

2 (3%)

1 (3.6%)

 Other

3 (3%)

2 (3%)

1 (3.6%)

Clinical respiratory findings

 Respiratory rate

32 [26–37]

33 [27–38]

30 [26–33]

 Signs of respiratory failure

48 (46%)

33 (49%)

15 (54%)

 Rhonchi

15 (14%)

9 (15%)

6 (21%)

 Crackles

54 (52%)

36 (47%)

18 (64%)

 Signs of consolidation

7 (7%)

5 (9%)

2 (7%)

 Decreased vesicular breath sounds

14 (13%)

10 (17%)

4 (14%)

Clinical presentation

 Time since symptom onset (days)

5 [3–8]

6 [4–9]

4 [2–7]

 Fever

77 (74%)

58 (83%)

19 (68%)

 Shock

10 (10%)

6 (8%)

4 (14%)

 Neurological symptoms

32 (31%)

19 (25%)

13 (46%)

 Gastrointestinal symptoms

1 (1%)

1 (1%)

0

Extra-pulmonary signs

 ≥ 1 extra-pulmonary symptom

34 (33%)

27 (36%)

7 (25%)

 Arthritis

2 (2%)

1 (1%)

1 (3.5%)

 Myocarditis

4 (4%)

4 (5%)

0

Treatments in the ICU

 Mechanical ventilation

75 (72%)

50 (66%)

25 (89%)

 Duration of ventilation

13 [8–19]

12.5 [8–22.5]

13.5 [8.5–19]

 Vasopressors

41 (39%)

26 (34%)

15 (54%)

 Renal replacement therapy

10 (9.5%)

7 (9%)

3 (11%)

Outcomes

 Death in the ICU

11 (10%)

6 (8%)

5 (18%)

 Length of ICU stay (days)

  Discharged alive

15 [8–26]

15 [8–27]

19 [12–24]

  ICU death

39 [25–49]

37 [26–47]

39 [25–90]