SpO2 & BOS Screening
Recommendation
Consider spirometry within 2-4 weeks. Closer clinical follow-up.
Note: SpO2 monitoring is supplementary screening and cannot substitute for pulmonary function testing (spirometry). Normal SpO2 does not exclude early-stage BOS (bronchiolitis obliterans syndrome).
1. SpO2 Nightly Trend
Slope: -0.00654%/day (-0.196%/month). 95% CI: [-0.00816, -0.00491]. p=0.0000.
Prediction:
| Time Horizon | Predicted SpO2 | 95% PI |
|---|---|---|
| 30d | 94.5% | [92.6, 96.5]% |
| 60d | 94.3% | [92.4, 96.3]% |
| 90d | 94.2% | [92.2, 96.1]% |
Concern Level: LOW
2. Desaturation Events
Absolute threshold (<94%): 18 nights (8.4%)
Relative threshold (<95.56%, baseline-2SD): 87 nights (40.5%)
Frequency trend: First half: 0.9% vs second half: 15.7% - INCREASING FREQUENCY
3. SpO2 Variability
Overall SD: 1.085% | CV: 1.135%
Night-to-night difference SD: 1.241%
First half SD: 0.669% vs second half: 1.184% - INCREASING VARIABILITY
4. SpO2-HR Coupling
Pearson r: 0.162 (p=0.011804)
Spearman rho: 0.2 (p=0.001811)
Status: DECOUPLED (positive - abnormal)
Interpretation: Positive SpO2-HR coupling suggests loss of the expected compensatory inverse response.
Normal: Inverse relationship (SpO2 down -> HR up, compensatory). Decoupling (positive or zero correlation) = autonomic dysfunction or respiratory failure.
5. DLCO-SpO2 Correlation
DLCO Measurements:
| Date | DLCO% | Context | Concurrent SpO2 |
|---|---|---|---|
| 2024-03-21 | 71% | Baseline post-HSCT | No data |
| 2025-03-20 | 89% | Improvement | No data |
| 2025-12-17 | 67% | Concerning decline | No data |
DLCO Trajectory: 71% (Baseline post-HSCT) -> 89% (Improvement) -> 67% (Concerning decline)
SpO2 monitoring started after the last DLCO measurement. Direct correlation not possible, but trend direction is consistent with DLCO decline.
6. Breathing Disturbance Index (BDI)
Mean BDI: 3.42 events/hour (status: NORMAL)
Elevated nights (>=5): 68 of 215 (31.6%)
BDI trend: slope=-0.0201/day (p=0.0)
7. SpO2-Temperature Coupling
Pearson r: -0.1967 (p=0.00379)
Interpretation: Weak coupling: SpO2 relatively independent of temperature
8. BOS Risk Score
Composite Score: 39/100 - MODERATE
| Component | Score | Weight | Contribution |
|---|---|---|---|
| SpO2 Trend | 16/100 | 30% | 4.9 |
| SpO2 Variability | 57/100 | 20% | 11.4 |
| Desaturation Frequency | 50/100 | 20% | 10.0 |
| Breathing Disturbance Index (BDI) | 20/100 | 15% | 3.1 |
| HR Decoupling | 66/100 | 15% | 9.9 |
9. Pre/Post Ruxolitinib
Pre-ruxolitinib (55 nights): 96.079% (SD: 0.569%)
Post-ruxolitinib (160 nights): 95.456%
Status: Statistically significant SpO2 deterioration after ruxolitinib
Mann-Whitney U: 5917.0 (p=0.000139), effect size (rbc)=-0.3448