Loop Gain As a Means to Predict a Positive Airway Pressure Suppression of Cheyne-Stokes Respiration in Patients with Heart Failure

Sands, Scott A.; Edwards, Bradley A.; Kee, Kirk; Turton, Anthony; Skuza, Elizabeth M.; Roebuck, Teanau; O'Driscoll, Denise Marie; Hamilton, Garun S.; Naughton, Matthew T.; Berger, Philip J.

doi:10.1164/rccm.201103-0577oc

Cited by 113 publications

(104 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Duty ratio (DR) was calculated as a surrogate for loop gain (Edwards et al, 2008;Sands et al, 2011), using methods described elsewhere (Andrews et al, 2012). Briefly, apneas were scored as a drop in the peak signal excursion by ≥90% of pre-event baseline using the oro-nasal sensor for ≥10 s with associated absent inspiratory effort throughout the entire period of absent airflow, and hypopneas scored as a peak signal excursion drop by ≥30% of pre-event baseline using nasal pressure for ≥10 s with a ≥3% oxygen desaturation from pre-event baseline, unless the apneas or hypopneas occurred as a segment of continuous periodic breathing, in which case the entire duration of the respiratory event was taken.…”

Section: Data Analysis and Statistical Measuresmentioning

confidence: 99%

Bed rest and hypoxic exposure affect sleep architecture and breathing stability

et al. 2017

View full text Add to dashboard Cite

Section: Data Analysis and Statistical Measuresmentioning

confidence: 99%

Bed rest and hypoxic exposure affect sleep architecture and breathing stability

et al. 2017

View full text Add to dashboard Cite

“…CPAP may mitigate post-apneic ventilatory overshoot by increasing lung volumes and decreasing loop gain. 11 The majority of patients with central apnea have concomitant obstructive apnea, 12 and many others demonstrate upper airway narrowing or occlusion during central apneic events. 13 Therefore, a trial of CPAP therapy remains the treatment of choice.…”

Section: Co M M Entarymentioning

confidence: 99%

Adaptive Servo-Ventilation and Central Apnea Associated with Systolic Heart Failure

Shafazand

Badr

2016

Journal of Clinical Sleep Medicine

View full text Add to dashboard Cite

In individuals with symptomatic congestive heart failure (left ventricular ejection fraction ≤ 45%) and predominately central sleep apnea, does treatment of the sleep apnea with adaptive servo-ventilation (ASV), in addition to guideline based medical treatment change time to first event (composite of first event of death from any cause, lifesaving cardiovascular intervention [cardiac transplantation, implantation of a ventricular assist device, resuscitation after sudden cardiac arrest, or appropriate lifesaving shock], or unplanned hospitalization for worsening heart failure)? Methods DesignMulti-center, randomized, controlled trial; clinicaltrials.gov identifier: NCT00733343. AllocationRandomization was conducted by a centralized computer system. Allocation was stratified by country. The randomization sequence was concealed. BlindingThe investigators and participants were not blinded to study arm assignment. The primary outcome measurements were blinded. Follow-up periodThis was an event driven analysis. Participants were recruited over a period of 60 months with a total of 2-year follow-up until the target 651 observed events was reached. SettingPatients were recruited from each investigator's network of sleep and cardiology practices.

show abstract

“…36 However, the chemoreflex feedback loop gain of the current respiratory model could be estimated with the durations of the ventilatory phase and of the CSR cycle by using the formula proposed by Sands et al 37 The loop gain was thus calculated as around 1, which corresponded to a patient with moderate severity of ventilatory instability. 37 Further, this study only simulated common SDB events with different mechanisms independently, while the combinations of these mechanisms in the same event were not taken into account, such as central apnea with closed upper airway, which sometimes appears in the patients of heart failure. 38 The bench may be very appropriate to test these central apneas with closed airways.…”

Section: Limitations Of the Studymentioning

confidence: 99%

Bench Test Evaluation of Adaptive Servoventilation Devices for Sleep Apnea Treatment

Zhu

Kharboutly²,

Ma³

et al. 2013

Journal of Clinical Sleep Medicine

View full text Add to dashboard Cite

Rationale: Adaptive servoventilation devices are marketed to overcome sleep disordered breathing with apneas and hypopneas of both central and obstructive mechanisms often experienced by patients with chronic heart failure. The clinical effi cacy of these devices is still questioned. Study Objectives: This study challenged the detection and treatment capabilities of the three commercially available adaptive servoventilation devices in response to sleep disordered breathing events reproduced on an innovative bench test. Methods:The bench test consisted of a computer-controlled piston and a Starling resistor. The three devices were subjected to a fl ow sequence composed of central and obstructive apneas and hypopneas including Cheyne-Stokes respiration derived from a patient. The responses of the devices were separately evaluated with the maximum and the clinical settings (titrated expiratory positive airway pressure), and the detected events were compared to the bench-scored values. Results: The three devices responded similarly to central events, by increasing pressure support to raise airfl ow. All central apneas were eliminated, whereas hypopneas remained. The three devices responded differently to the obstructive events with the maximum settings. These obstructive events could be normalized with clinical settings. The residual events of all the devices were scored lower than bench test values with the maximum settings, but were in agreement with the clinical settings. However, their mechanisms were misclassifi ed. Conclusion:The tested devices reacted as expected to the disordered breathing events, but not suffi ciently to normalize the breathing fl ow. The device-scored results should be used with caution to judge effi cacy, as their validity depends upon the initial settings. S C I E N T I F I C I N V E S T I G A T I O N SA uto-titrating continuous positive airway pressure ventilators (auto-CPAP) have been developed by manufacturers for the treatment of obstructive sleep apnea with the assumption that lower pressure application would be more comfortable and thus improve compliance and long-term patient outcomes. 1,2However, a recent meta-analysis of auto-CPAP devices has found a limited clinical relevance of only 0.2 h per night of additional use compared to common CPAP devices.3 Clinical studies have recently shown that this limitation may be due to a failure of auto-CPAP devices to reliably estimate the therapeutic pressure in up to 25% of patients. [4][5][6][7] It is noteworthy that bench testing of these devices has predicted these detection and response limitations under simulated obstructive events. [8][9][10][11] More recently, some manufacturers have developed new devices based on adaptive servoventilation (ASV) to treat patients with mixed events of alternating central and obstructive mechanisms as observed in heart failure 12 or so-called complex sleep apnea (CompSA). 13 These ASV devices apply a closed-loop mechanical ventilation, pressure preset, and volume or airfl ow cycled.14 The aim of thes...

show abstract

Loop Gain As a Means to Predict a Positive Airway Pressure Suppression of Cheyne-Stokes Respiration in Patients with Heart Failure

Abstract: Our novel LG estimate enables quantification of the severity of ventilatory instability underlying PB, making possible a priori selection of patients whose PB is immediately treatable with CPAP therapy.

Cited by 113 publications

References 47 publications

Bed rest and hypoxic exposure affect sleep architecture and breathing stability

Bed rest and hypoxic exposure affect sleep architecture and breathing stability

Adaptive Servo-Ventilation and Central Apnea Associated with Systolic Heart Failure

Bench Test Evaluation of Adaptive Servoventilation Devices for Sleep Apnea Treatment

Contact Info

Product

Resources

About