Table 3.
Laboratory data on hospital admission and imaging findings
| COVID-19 (n = 65) | Influenza (n = 74) | P Value* | |
|---|---|---|---|
| Admission laboratory data† | |||
| White blood cell count | |||
| Median (IQR), per mm3 | 7,240 (5,430–11,820) | 9,035 (6,590–14,900) | 0.007 |
| Distribution, n/total n (%) | |||
| ≥10,000 per mm3 | 22 (33.9) | 30 (40.5) | — |
| ≤4,000 per mm3 | 6 (9.2) | 3 (4.1) | — |
| Neutrophil count | |||
| Median (IQR), per mm3 | 5,405 (3,880–9,580) | 7,210 (4,990–11,890) | 0.02 |
| Lymphocyte count | |||
| Median (IQR), per mm3 | 910 (550–1,350) | 800 (590–1,220) | 0.48 |
| Distribution, n/total n (%) | |||
| ≤1,500/mm3 | 50/62 (80.7) | 57/71 (80.3) | — |
| Aspartate aminotransferase >40 U/L, n/total n (%) | 31/59 (52.5) | 31/65 (47.7) | 0.59 |
| Alanine aminotransferase >40 U/L, n/total n (%) | 21/59 (35.6) | 21/65 (32.3) | 0.70 |
| Lactate, median (IQR), mmol/L | 1.55 (1.2–2.45) | 2.15 (1.5–3.4) | 0.48 |
| Lactate ≥1.5 mmol/L, n/total n (%) | 31/52 (59.6) | 50/64 (78.1) | — |
| C-reactive protein, median (IQR), mg/L | 148.5 (76.2–219.7) | — | — |
| Lactate dehydrogenase, median (IQR), U/L | 419 (322–513) | — | — |
| Interleukin-6, median (IQR), pg/ml | 160.5 (71–254) | — | — |
| Laboratory data during first 3 d of ICU admission‡ | |||
| Highest serum creatinine, median (IQR), mg/dl | 1.13 (0.89–1.92) | 1.10 (0.82–1.63) | 0.82 |
| Highest troponin ≥0.06 ng/ml, n/total n (%) | 16/56 (28.6) | 21/56 (37.5) | 0.32 |
| Lowest platelets, median (IQR), per mm3 | 187 (149–230) | 168 (118–206) | 0.04 |
| Highest bilirubin, median (IQR), mg/dl | 0.6 (0.5–0.9) | 0.7 (0.4–1.2) | 0.15 |
| Creatine kinase ≥100 U/L, n/total n (%) | 18/27 (66.7) | 9/13 (69.2) | 1.00 |
| Daily PaO2/FiO2 ratio during mechanical ventilation§ | |||
| Day 1 lowest PaO2/FiO2 ratio, median (IQR) | 126 (73–165) | 101.5 (83–188) | 0.311 |
| Day 2 lowest PaO2/FiO2 ratio, median (IQR) | 120 (96–167) | 167.5 (98–252.5) | 0.02 |
| Day 3 lowest PaO2/FiO2 ratio, median (IQR) | 121 (98–145) | 181 (127–216.5) | 0.006 |
| Infection analyses, n/total n (%)‖ | |||
| Blood cultures (positive) | 7/46 (15.2) | 4/49 (8.2) | 0.28 |
| Early blood cultures (positive) | 1/7 (14.3) | 3/4 (75.5) | 0.09 |
| Sputum cultures (positive) | 22/34 (64.7) | 18/34 (52.9) | 0.32 |
| Early sputum cultures (positive) | 6/22 (27.2) | 13/18 (72.2) | 0.005 |
| Influenza A | 0/47 | 58 (78.4) | — |
| Influenza B | 0/47 | 16 (21.6) | — |
| Extended-spectrum respiratory viruses (positive) | 1/17 (5.9) | 4/36 (11.1) | 1.0 |
| Chest radiographic findings, n/total n (%)¶ | |||
| Clear chest radiograph | 1/63 (1.6) | 14/73 (19.2) | 0.001 |
| Bilateral opacities | 57/63 (90.5) | 38/73 (52.1) | <0.001 |
| Pleural effusion | 7/63 (11.1) | 10/73 (13.7) | 0.65 |
Definition of abbreviations: COVID-19 = coronavirus disease; FiO2 = fraction of inspired oxygen; ICU = intensive care unit; IQR = interquartile range; PaO2 = partial pressure of arterial oxygen; SARS-CoV-2 = severe acute respiratory syndrome coronavirus 2.
Data are presented as medians (IQRs) for continuous variables and as counts with frequencies (%) for binary and categorical variables. The total number is given if values are missing.
P values were calculated using a t test for continuous variables and a chi-square test or Fisher exact test for binary and categorical variables.
There were 6 missing values for the neutrophil count and lymphocyte count, 15 missing values for aspartate aminotransferase and alanine aminotransferase, and 23 missing values for lactate. Lactate included either arterial or venous lactate. For CRP (c-reactive protein), LDH (lactate dehydrogenase), and IL-6 (interleukin-6), values are presented only for patients with COVID-19 because of the large number of missing values in patients with influenza. For COVID-19, there were 20 missing CRP values, 24 missing LDH values, and 33 missing IL-6 values.
There was 1 missing creatinine value, and there were 11 missing bilirubin values.
Among 80 patients who were mechanically ventilated, the PaO2/FiO2 ratio is missing for five patients on Day 1, 28 patients on Day 2, and 35 patients on Day 3.
Viral testing was performed on nasopharyngeal swab, endotracheal aspirate, or bronchoalveolar lavage samples. Extended-spectrum testing included metapneumovirus, parainfluenza, respiratory syncytial virus, (non–SARS-CoV-2) coronavirus, rhinovirus, adenovirus, or bocavirus.
Reported only for chest radiograph within first 3 days of hospitalization.