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Background: Cardiovascular events commonly cause death in amyotrophic lateral sclerosis (ALS) even in patients treated by noninvasive ventilation (NIV)., Objectives: to evaluate autonomic function with the assessment of heart rate variability (HRV) in ALS patients treated by assist pressure control ventilation (APCV) and assist control ventilation (ACV) during sleep., Methods: Consecutive ALS patients underwent one polysomnography during APCV and one during ACV. HRV was analyzed both in the total sleep period (from first stage N1 to last awakening) and in a 5-minute period of stable stage N2. Time domain, frequency domain and nonlinear indexes of HRV were measured., Results: Nineteen patients (age 62.0 ± 8.7, 9F/10 M) were studied. The analysis did not reveal differences in blood gasses between NIV modalities, but a longer expiratory time (3.01±0.6 vs 2.8 ± 0.6 s, respectively APCV vs ACV, p = 0.001) and a lower arousal index (17.5 ± 9.1 vs 23.1 ± 13.9, p = 0.02) during APCV. HRV was indicative of higher vagal activity during APCV, especially in the 5-minute periods. In the total sleep periods, the HRV time domain indexes reflecting parasympathetic activity were positively correlated with the expiratory time and negatively with the inspiratory/expiratory time ratio. Low frequencies were positively, and high frequencies negatively, correlated with inspiratory time. HRV and sleep structure parameters were not correlated, except very low frequencies that were correlated to the arousal index., Conclusions: Respiratory influences on autonomic control can be preserved in ALS. The slower breathing pattern during APCV may help to maintain a higher vagal activity. Through this mechanism, in the long-term APCV could more beneficial to ALS patients than ACV., Competing Interests: Declaration of Competing Interest None., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Comparison of the effects of pressure controlled and volume controlled noninvasive ventilations (NIV) has usually been limited to the degree of improvement in blood gases. We compared sleep quality, abnormal respiratory events, and patient-ventilator asynchronies during administration of pressure controlled continuous mandatory ventilation (PC-CMV) and volume controlled continuous mandatory ventilation (VC-CMV) in subjects with amyotrophic lateral sclerosis naive to NIV after titration aimed at maximally improving nocturnal arterial blood gases., Methods: A crossover evaluation of PC-CMV and VC-CMV was performed in 27 subjects with amyotrophic lateral sclerosis. After baseline polysomnography, ventilators were set in random order so as to warrant similar and satisfactory oxygen saturation and transcutaneous [Formula: see text] in both NIV modalities during day and night. Soon after titration, polysomnography was repeated during administration of each type of NIV., Results: With respect to the baseline night, non-rapid eye movement 3, and rapid eye movement sleep stages increased, and the arousal index decreased during PC-CMV ( P = .005, P = .02, and P = .01, PC-CMV vs VC-CMV, respectively) but not during VC-CMV. The arousal index during NIV was correlated to the peak pressure delivered by the ventilators (ρ = 0.47, P < .001). Few abnormal respiratory events were observed in both NIV modes. Patient-ventilator asynchronies were more frequent during VC-CMV (median [IQR] 20.8 [0.0 - 22.0] vs 31.8 [30.1 - 34.0] no./h, PC-CMV vs VC-CMV; P = .002). Twenty-one subjects declared that they preferred PC-CMV therapy., Conclusions: In the short term, PC-CMV may be a preferred NIV modality to VC-CMV for patients with amyotrophic lateral sclerosis, even when both NIV modes are similarly effective in the correction of hypoventilation. Evaluation of the effectiveness of NIV should not be limited to the assessment of blood gas correction., (Copyright © 2021 by Daedalus Enterprises.)

Objective: In amyotrophic lateral sclerosis (ALS), early recognition of nocturnal hypoventilation (NH) is essential to start noninvasive ventilation (NIV), but nocturnal transcutaneous PCO 2 (PtcCO 2 ) is difficult to monitor. Usefulness of respiratory and muscular function test in the prediction of NH has been explored without distinguishing among ALS phenotypes. We evaluated cross-sectional relationships between functional tests and nocturnal PCO 2 , and the best predictors of NH, separately in patients with spinal and bulbar onset of ALS. Methods : ALS patients candidate to NIV were recruited. Diurnal respiratory and muscular function tests and nocturnal polysomnography with PtcCO 2 monitoring were performed. NH was defined as peak PtcCO 2 >49 mm Hg. Results : Thirty-six patients with spinal and 11 with bulbar onset ALS were included. Nocturnal oxygen saturation and PtcCO 2 , and proportion of subjects with NH were similar in each group (spinal: 50%; bulbar: 45.5%). Significant differences between groups were found in forced vital capacity ( p  = 0.03), maximal inspiratory pressure ( p  = 0.01) and sniff nasal inspiratory pressure (SNIP) ( p  = 0.007), but not in diurnal arterial blood gases. In the spinal group, SNIP and Base Excess (BE) independently predicted nocturnal PtcCO 2 (R 2 0.59, p  < 0.0001). In the bulbar group only SNIP was correlated to PtcCO 2 , but it varied little in relationship to PtcCO 2 changes. Conclusions : Respiratory and muscle function parameters are differently related to NH in ALS patients with spinal and bulbar presentation. SNIP and BE may be helpful to reveal NH in spinal patients, while in bulbar patients no respiratory or muscle function tests may reliably predict NH.

Purpose: The study aims to evaluate the performance of autonomic activations as a tool to assess sleep fragmentation and to recognize hypopneas in patients with amyotrophic lateral sclerosis (ALS) under non-invasive mechanical ventilation and secondarily, to evaluate, in patients with the same disease, the relationship between disruption of autonomic nervous system (ANS) activity and the usefulness of the autonomic activations as surrogates of cortical arousals., Methods: Sixteen ALS patients underwent simultaneous polysomnography and portable cardiorespiratory monitoring (PM). On the polysomnography, standard rules were used for scoring arousals and respiratory events. On the PM, autonomic arousals were scored as ≥ 15% heart rate (HR) increase with a ≥ 35% pulse wave amplitude (PWA) reduction, HR increase ≥ 20%, or PWA decrease ≥ 40%. Nocturnal HR variability was analyzed in the ALS patients and in 11 control subjects as an index of ANS activity., Results: Synchronized epoch by epoch analysis of the polysomnography and PM recordings showed that only 31.0 (22.5-58.7)% cortical and 36.1 (20.5-47.2)% autonomic arousals were associated with one another. Among hypopneas scored at polysomnography, 71.7% were associated with a cortical arousal but not with a desaturation. On average, HR variability in ALS showed signs of depressed ANS activity that was particularly evident in the patients where the cortical arousals exceeded the autonomic ones., Conclusions: In ventilated ALS patients, autonomic activations may hardly have a role as surrogates of cortical arousals for assessment of sleep fragmentation and for respiratory scoring. Depression of ANS activity may be related to their poor performance.

Background and Objective: No studies have evaluated the impact of different settings of non-invasive ventilation (NIV) in patients affected by amyotrophic lateral sclerosis (ALS). We explored consequences of positive end-expiratory pressure (PEEP) application on effectiveness of ventilation, sleep architecture and heart rate variability (HRV) in patients with ALS naïve to ventilatory treatment., Methods: In two consecutive nights, 25 patients received in random order 0 or 4 cm H2 0 of PEEP during nocturnal NIV administration (Idea Ultra ResMed) with the same level of total positive inspiratory pressure. Polysomnographies were performed to evaluate sleep and NIV quality, as well as HRV. HRV was analyzed on 4-h periods and on 5-min segments of stable NREM sleep., Results: We did not observe differences in gas exchanges during NIV with and without PEEP. Conversely, during PEEP application increases in leaks (41.4 ± 29.3% vs 31.0 ± 25.7%, P = 0.0007) and in autotriggerings (4.2 (IQR 1.3-10.0) vs 0.9 (IQR 0.0-3.0) events/h, P < 0.001, PEEP vs no PEEP, respectively) occurred. Besides, N3 sleep stage duration decreased (2.5% (IQR 0.0-18.0) vs 0.0% (IQR0.0-12.1), P = 0.001) and arousal/awakening index increased (16.9 ± 7.4 vs 13.4 ± 5.0 events/h, P = 0.01). Data on HRV were available in 15 patients. A higher low/high frequency ratio, either in the 4-h (3.8 ± 2.6 vs 2.9 ± 1.7, P = 0.04, PEEP vs no PEEP, respectively) or in the 5-min segments (2.6 ± 1.8 vs 1.45 ± 0.9 P = 0.01) was found during PEEP administration., Conclusion: In ALS patients, PEEP application during NIV was associated with worse NIV and sleep quality and with higher sympathetic activity., (© 2016 Asian Pacific Society of Respirology.)