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: -0.00334%/day (-0.100%/month). 95% CI: [-0.00580, -0.00089]. p=0.0079.
Prediction:
| Time Horizon | Predicted SpO2 | 95% PI |
|---|---|---|
| 30d | 95.6% | [94.1, 97.1]% |
| 60d | 95.5% | [94.0, 97.0]% |
| 90d | 95.4% | [93.9, 96.9]% |
Concern Level: LOW
2. Desaturation Events
Absolute threshold (<94%): 2 nights (1.5%)
Relative threshold (<95.56%, baseline-2SD): 33 nights (24.1%)
Frequency trend: First half: 0.0% vs second half: 2.9% - INCREASING FREQUENCY
3. SpO2 Variability
Overall SD: 0.754% | CV: 0.785%
Night-to-night difference SD: 0.862%
First half SD: 0.549% vs second half: 0.908% - INCREASING VARIABILITY
4. SpO2-HR Coupling
Pearson r: 0.0219 (p=0.790506)
Spearman rho: 0.0467 (p=0.570403)
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: 4.57 events/hour (status: NORMAL)
Elevated nights (>=5): 65 of 137 (47.4%)
BDI trend: slope=-0.0158/day (p=0.005576)
7. SpO2-Temperature Coupling
Pearson r: -0.2246 (p=0.008311)
Interpretation: Weak coupling: SpO2 relatively independent of temperature
8. BOS Risk Score
Composite Score: 22/100 - MODERATE
| Component | Score | Weight | Contribution |
|---|---|---|---|
| SpO2 Trend | 8/100 | 30% | 2.5 |
| SpO2 Variability | 28/100 | 20% | 5.7 |
| Desaturation Frequency | 12/100 | 20% | 2.4 |
| Breathing Disturbance Index (BDI) | 27/100 | 15% | 4.1 |
| HR Decoupling | 52/100 | 15% | 7.8 |
9. Pre/Post Ruxolitinib
Pre-ruxolitinib (55 nights): 96.079% (SD: 0.569%)
Post-ruxolitinib (82 nights): 95.953%
Status: No statistically significant change after ruxolitinib (yet)
Mann-Whitney U: 2442.5 (p=0.411577), effect size (rbc)=-0.0831