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Editorial
. 2017 May 15;13(5):657-664.
doi: 10.5664/jcsm.6574.

Urgent Need to Improve PAP Management: The Devil Is in Two (Fixable) Details

Robert J Thomas  1 , Matt T Bianchi  2
Affiliations
Editorial

Urgent Need to Improve PAP Management: The Devil Is in Two (Fixable) Details

Robert J Thomas et al. J Clin Sleep Med. .
No abstract available

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Figures

Figure 1
Figure 1. High loop gain sleep apnea: short-cycle periodic breathing with obstructive features.
This 5-minute diagnostic polysomnogram snapshot shows cycle-lengths of less than 30 seconds, a self-similar appearance of respiratory events, and events which may be scored central or obstructive from event to event. Note snoring appearing during arousals that during the events, rather than during the respiratory event, a commonly seen feature when periodic breathing coexists with obstructive features. In purely obstructive disease, snoring occurs during the event and resolves during the arousal. This patient has exclusively non-rapid eye movement dominant apnea. The effects of continuous positive airway pressure are shown in Figure 2. M1 and M2 are mastoid left and right common references, F, C, and O standard frontal, central, and occipital sites. PTAF = pneumotachogram air flow, THERM = Thermistor, LAT/RAT = left and right anterior tibial electromyogram, EKG = electrocardiogram, SaO2 = fingertip oxygen saturation, Pleth = oximeter-derived plethysmography.
Figure 2
Figure 2. Residual undetected respiratory events during continuous positive airway pressure (CPAP) therapy in high loop gain sleep apnea.
The same subject as in Figure 1, after over 6 months of CPAP therapy. Residual sleepiness and fatigue persists. EncoreAnywhere (Philips Respironics) data, each horizontal line is 6 minutes. Note persistent short-cycle respiratory events almost entirely undetected by the algorithm, arrows identify two examples.
Figure 3
Figure 3. Opiate-associated sleep apnea.
Snapshot from EncoreAnywhere (Philips Respironics) in a patient who uses high dose opiates and is treated with continuous positive airway pressure (CPAP), acetazolamide and enhanced expiratory rebreathing space (dead space, EERS). Each horizontal line represents 6 minutes. Note: (1) Variability of expiratory duration, the typical opiate effect. (2) Variable respiratory rates including bradypnea. (3) False detection of obstructive events, with tags falling on all parts of the respiratory cycle-expiratory and inspiratory, suggesting that the detection algorithm is unable to accurately process ataxic breathing patterns. The machine-detected apnea-hypopnea index was 22, though the patient noted refreshing sleep. Long arrow identifies a short expiratory duration, short arrow identifies a long duration. H = hypopnea, OA = obstructive apnea.
Figure 4
Figure 4. Complex respiratory waveforms and software detection limitations.
Snapshot from EncoreAnywhere (Philips Respironics) in a 52-year-old man not using opiates but with uncertain cause of ataxic respiration. Brain and high spinal magnetic resonance imaging was normal. Note the substantially pathological respiratory patterns (apneas, ataxic rhythm, clusters of tachypnea) largely undetected by the software. Six minutes per horizontal line of flow. The two downward pointing black arrows are examples of points of abrupt shifts in rate and rhythm of respiration. CA = central apnea, H = hypopnea, OA = obstructive apnea.
Figure 5
Figure 5. Missed event during continuous positive airway pressure use.
Various samples, each from different patients, at different compressions to show events tagged and missed auto-detection via the algorithms. The missed events are tagged with star symbols. AHI = apnea-hypopnea index, CA = central apnea, H = hypopnea, OA = obstructive apnea.
Figure 6
Figure 6. Adaptive ventilation and pressure cycling.
(A) Effective adaptive ventilation with largely stable pressure and expiratory time over the course of the night. No events are detected. (B) Pressure cycling through much of the night. Note the variance in expiratory duration, and the relative paucity of events detected, only in the areas of greater pressure cycling. Pressure is in cm H2O, and flow rate in L/min. CA = clear airway event, presumably central apnea, Exp. Time = expiratory time (in seconds), Insp. Time = inspiratory time (in seconds), LL = large leak, OA = obstructive apnea, UA = unclassified apnea.
Figure 7
Figure 7. Pressure cycling at high resolution.
Two samples, from different patients, of pressure cycling in response to ongoing flow cycling, which appears to be subthreshold to detection algorithm (apnea-hypopnea index, zero). Arrows point to some examples of pressure surges, but note non-detection of flow events.
See this image and copyright information in PMC

References

    1. Kushida CA, Nichols DA, Holmes TH, et al. Effects of continuous positive airway pressure on neurocognitive function in obstructive sleep apnea patients: the Apnea Positive Pressure Long-term Efficacy Study (APPLES) Sleep. 2012;35(12):1593–1602. - PMC - PubMed
    1. Cowie MR, Woehrle H, Wegscheider K, et al. Adaptive servo-ventilation for central sleep apnea in systolic heart failure. N Engl J Med. 2015;373(12):1095–1105. - PMC - PubMed
    1. McEvoy RD, Antic NA, Heeley E, et al. CPAP for prevention of cardiovascular events in obstructive sleep apnea. N Engl J Med. 2016;375(10):919–931. - PubMed
    1. Gottlieb DJ, Punjabi NM, Mehra R, et al. CPAP versus oxygen in obstructive sleep apnea. N Engl J Med. 2014;370(24):2276–2285. - PMC - PubMed
    1. Berry RB, Kushida CA, Kryger MH, Soto-Calderon H, Staley B, Kuna ST. Respiratory event detection by a positive airway pressure device. Sleep. 2012;35(3):361–367. - PMC - PubMed

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