Volume 20, Number 9—September 2014
Dispatch
Risk Factors for Severe Influenza A–Related Pneumonia in Adult Cohort, Mexico, 2013–14
, Martin Magaña-Aquino, Sofía Bernal-Silva, Javier Araujo-Meléndez, Andreu Comas-García, Emma Alonso-Zúñiga, Eliana Torres-Torres, and Daniel E. Noyola
Table 1
Characteristics of 102 patients with severe pneumonia who required mechanical ventilation compared with patients who did not require mechanical ventilation, San Luis Potosi, Mexico, 2013–14*
| Characteristic | Without mechanical ventilation (n = 50) | With mechanical ventilation (n = 52) | p value |
|---|---|---|---|
| Age, y, mean (SD) | 42.8 (13.6) | 46.2 (13.3) | |
| Gender, no. (%) | |||
| M | 25 (50) | 25 (48.1%) | 0.21 |
| F | 25 (50) | 27 (51.9%) | 0.85 |
| Presence of ≥1 underlying conditions, no. (%) | 38 (76) | 44 (84.6%) | 0.27 |
| Obesity (body mass index >30) † | 23 (46.9) | 39 (76.5%) | 0.002 |
| Diabetes mellitus | 12 (24) | 11 (21.2%) | 0.73 |
| Immunosuppression‡ | 4 (8) | 5 (9.6%) | 1.0 |
| Asthma-COPD-bronchiectasis | 8 (16) | 1 (1.9%) | 0.01 |
| Other § | 9 (18) | 3 (5.8%) | 0.06 |
| Underlying disorders, excluding obesity, no. (%) | 27 (54) | 21 (40.4%) | 0.17 |
| Influenza vaccination during most recent season, no. (%) | 8 (16) | 0 | 0.002 |
| Signs and symptoms, no. (%) | |||
| Fever | 49 (98) | 52 (100%) | 0.49 |
| Headache | 45 (90) | 49 (94.2%) | 0.48 |
| Cough | 50 (100) | 52 (100%) | NA |
| Myalgias | 46 (92) | 46 (88.5%) | 0.74 |
| Dyspnea | 50 (100) | 52 (100%) | NA |
| Blood-streaked sputum | 14 (28) | 15 (28.8%) | 0.92 |
| Diarrhea | 9 (18) | 6 (11.5%) | 0.36 |
| Clinical findings, mean (SD) | |||
| Body mass index* | 29.6 (4.8) | 31.9 (3.9) | 0.01 |
| Respiratory rate, bpm | 26.4 (3.3) | 30.3 (5) | <0.001 |
| Cardiac rate, bpm | 102.6 (12.4) | 109.2 (16.9) | 0.03 |
| Mean blood pressure, mmHg | 80.6 (11.3) | 74.2 (14.6) | 0.01 |
| Temperature, °C | 38.5 (0.5) | 38.5 (0.5) | 0.42 |
| PaO2/FiO2 | 236 (49.2) | 119.8 (43.8) | <0.001 |
| Laboratory findings, mean (SD) | |||
| Total WBCs, x103/μL† | 8.1 (4.3) | 7.4 (3.9) | 0.39 |
| Lymphocytes, x103/μL† | 1.2 (0.75) | 0.84 (0.64) | 0.01 |
| Platelet count, x103/μL† | 223.5 (93.1) | 212.4 (125.4) | 0.62 |
| C-reactive protein, mg/dL† | 12.9 (8.8) | 19.7 (11.6) | 0.001 |
| Lactate dehydrogenase, U/L # | 406.8 (416.6) | 694.6 (547.4) | 0.006 |
| CPK, U/L ** | 349.5 (760.1) | 575.9 (544.4) | 0.1 |
| Symptom onset | |||
| Duration of symptoms before dyspnea, d, mean (SD) | 2.8 (2.8) | 3.1 (3.3) | 0.67 |
| Dyspnea duration before admission, d, mean (SD) | 3.9 (2.8) | 3.7 (2.7) | 0.75 |
| Duration of symptoms before hospital admission, d, mean (SD) | 6.7 (3.8) | 6.6 (3.5) | 0.99 |
*Statistical analyses used included Fisher exact test, χ2 test, and Student t test. SD, standard deviation; COPD, chronic obstructive pulmonary disease; PaO2/FiO2, partial pressure arterial oxygen and fraction of inspired oxygen ratio; CPK, creatine phosphokinase; U/L, units per liter.
†Data available for 100 patients
‡Immunosuppressed patients include patients with autoimmune disorders (4 cases; one of them with renal transplantation), HIV infection (3 cases), lymphoma (1 case), and chronic renal failure (1 case).
§Other disorders include cardiopathy (5 cases), Down syndrome (3 cases; 1 with cardiopathy), hypothyroidism (3 cases), pregnancy (1 case), and obstructive sleep apnea syndrome (1 case)
¶Data available for 98 patients
#Data available for 93 patients
**Data available for 91 patients