Table 2 Distribution of patients according to clinical severity and HRCT characteristics with estimation of proportionate severity factor
Clinical severity (respiratory status): | Group (1) mild | Group (2) border line severity | Group (3) severe–critical | Estimation of “total severity factor" and approximated score points | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
- - - | O2 saturation and requirements: Dyspnea: Respiratory rate (RR): | 95–100%, Absent or mild (type I) RR < 30/min | 93–94% (+) one of: High grade (type II or III) RR ≥ 30/min | < 93% (O2 support or ventilation) High grade (type II or III) RR ≥ 30/min | ||||||||||
- | Total number (TN) and percentage (379) | 298 (79%) | 57 (15%) | 24 (6%) | ||||||||||
HRCT characteristics: | N | % | a Severity ratio | N | % | Severity ratio | N | % | Severity ratio | Total | Points | |||
• Volumetric analysis: | ||||||||||||||
[S1] | 0–15% of lung volume is involved: | Total: | 271 (72%) | 271 | 100% | a 1.3 | Negative | Negative | 1.3 | 1 | ||||
[S2] | 15–25% of lung volume is involved: | Total: | 51 (13%) | 27 | 53% | 0.7 | 24 | 47% | 3.1 | Negative | 3.8 | 4 | ||
[S3] | 25–50% of lung volume is involved: | Total: | 49 (13%) | Negative | 33 | 67% | 4.5 | 16 | 33% | 5.5 | 10 | 10 | ||
[S4] | > 50% of lung volume is involved: | Total: | 8 (2%) | Negative | Negative | 8 | 100% | 16.7 | 16.7 | 17 | ||||
• Morphologic pattern: | ||||||||||||||
[M1] | Pure GGO: | Total: | 154 (41%) | 150 | 97% | 1.2 | 4 | 3% | 0.2 | Negative | 1.4 | 1 | ||
[M2] | GGOs with “Atoll sign”: | Total: | 50 (13%) | 46 | 92% | 1.2 | 4 | 8% | 0.5 | Negative | 1.7 | 2 | ||
[M3] | GGOs mixed with consolidations: | Total: | 80 (21%) | 70 | 87% | 1.1 | 10 | 13% | 0.9 | Negative | 2 | 2 | ||
[M4] | Homogeneous consolidations or “curvilinear” consolidations: | Total: | 29 (8%) | 15 | 52% | 0.7 | 14 | 48% | 3.2 | Negative | 3.9 | 4 | ||
[M5] | GGOs with “air bubble sign”: | Total: | 7 (2%) | 3 | 43% | 0.5 | 3 | 43% | 2.9 | 1 | 14% | 2.3 | 5.8 | 6 |
[M6] | GGOs with early secondary fibrosis and architectural distortion: | Total: | 26 (7%) | 7 | 27% | 0.3 | 11 | 42% | 2.8 | 8 | 31% | 5.2 | 8.3 | 8 |
[M7] | Patchy GGOs with smooth septal thickening “focal crazy-paving” pattern: | Total: | 26 (7%) | 7 | 27% | 0.3 | 11 | 42% | 2.8 | 8 | 31% | 5.2 | 8.3 | 8 |
Maximum (SF = 25) | ||||||||||||||
[M8] | It refers to diffuse alveolar damage pattern (DAD); - By definition, it is diffused (> 50%) of lung volume involvement [S4] - By definition, it represents mixed GGOs with “crazy-paving pattern” and “air bubble sign.” | |||||||||||||
Total: | 7 (2%) | Negative | Negative | 7 (100%) | ||||||||||