The edition · Pulmonology
The comfort setting on the CPAP machine was making the apnoea worse
Expiratory pressure alleviation reduced airway patency and left more residual events without improving adherence; eosinophil reference ranges vary sharply by age and sex; and interval training matched standard rehabilitation in fibrotic interstitial lung disease.
The edition in brief
A randomised study in 29 adults with severe obstructive sleep apnoea tested expiratory pressure alleviation, the comfort algorithm built into most CPAP devices. Activating it halved peak inspiratory flow during flow limitation (0.19 against 0.38 L/s), raised the manually titrated therapeutic pressure from 9.17 to 11.40 cmH2O, and left a higher residual apnoea-hypopnoea index on both fixed CPAP (3.7 against 1.3 events per hour) and auto-CPAP. Adherence was identical at about seven hours either way. A cross-sectional study of more than 680,000 Chinese health-check participants found blood eosinophil counts right-skewed, with a median of 100 cells per microlitre, higher in men than women (120 against 90) and following a U-shaped trajectory across age — arguing for age- and sex-stratified reference ranges rather than one threshold. A network meta-analysis of 34 publications and 1.46 million participants gives mortality hazard ratios by GOLD grade against normal spirometry: 1.09 for GOLD 1, 1.57 for GOLD 2, 2.39 for GOLD 3 and 4.54 for GOLD 4. A UNOS analysis of 37,091 lung transplant recipients found HLA-DR mismatch associated with graft failure only in recipients transplanted for COPD or interstitial pneumonia. A pearl covers the desaturation nobody recorded. The edition closes with a randomised trial of 131 people with fibrotic interstitial lung disease in which high-intensity interval training produced the same improvement in cycle endurance as standard moderate continuous training, with no adverse events in either arm.
Eosinophil thresholds are being applied to a count that varies by age and sex
Treat a single borderline eosinophil count as a percentile, not a verdict — repeat it before it decides treatment.
Mortality by GOLD grade, with the numbers to quote
Use grade-specific hazard ratios when discussing prognosis, and say plainly that GOLD 1 did not carry significantly raised mortality.
HLA-DR mismatch mattered after lung transplant, but only for two indications
Note the HLA-DR mismatch in COPD and interstitial pneumonia recipients — it is where the graft failure signal sits.
Interval training matched standard pulmonary rehabilitation in fibrotic lung disease
Interval training is a safe alternative in fibrotic interstitial lung disease, but it is not a better one.
The desaturation nobody recorded is the one that changes management
Record an exertional saturation, not just a resting one — a normal number at rest explains nothing about a breathless patient.
Turning on expiratory pressure relief left more apnoeas and did not improve adherence
If residual events persist on CPAP, turn off the expiratory pressure comfort setting before raising the pressure.
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