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Background: Sleep-disordered breathing (SDB) is frequent in patients with spinal-cord injury (SCI). However, SDB is frequently underdiagnosed due to limited access to diagnostic testing and knowledge about the condition. Moreover, SDB heterogeneity (sleep apnea, obstructive sleep apnea or central sleep apnea and nocturnal alveolar hypoventilation) implies complex evaluation of both nocturnal respiratory effort and hypercapnia. The aim of this study was to compare different screening strategies for an SDB diagnosis in patients with SCI., Methods: This was a retrospective analysis of data from subjects with SCI followed up in a tertiary-care rehabilitation center with a specialized sleep unit. Subjective (questionnaires) and objective data (polysomnography [PSG]), [Formula: see text] extracted from the PSG, morning blood gases, and nocturnal transcutaneous CO 2 (P tcCO 2 ) were collected and analyzed. A retrospective comparison of different strategies for SDB screening was carried out. Each strategy was compared (alone and in combination) with the standard of care for sleep apnea (PSG) and nocturnal alveolar hypoventilation (P tcCO 2 ) diagnosis. The performance of the usual cutoff and visual analysis was studied., Results: Among 190 subjects with SCI who underwent a full night's PSG, data were available for 104 questionnaires and 162 with oximetry. Nocturnal alveolar hypoventilation was screened by P tcCO 2 and blood gases in 52 subjects with SCI. Questionnaires (the modified Screening for Obstructive Sleep Apnea in Tetraplegia and the Epworth Sleepiness Scale) had poor performance for identifying sleep apnea and did not identify nocturnal alveolar hypoventilation. [Formula: see text] (oxygen desaturation index score ≥ 13) and visual analysis of [Formula: see text] were good at identifying sleep apnea but insufficient to identify nocturnal alveolar hypoventilation. Diurnal blood gases were poor predictors of nocturnal alveolar hypoventilation., Conclusions: Questionnaires were of limited use in subjects with SCI, but the oxygen desaturation index derived from oximetry performed well for sleep apnea screening. Both diurnal blood gases and oximetry visual analysis were insufficient for nocturnal alveolar hypoventilation screening. P tcCO 2 monitoring should be mandatory and ideally combined with PSG given the heterogeneity of SDB phenotypes and associated sleep comorbidities of patients with SCI., Competing Interests: The authors have disclosed no conflicts of interest., (Copyright © 2024 by Daedalus Enterprises.)

Background: Mechanical insufflation-exsufflation (MI-E) devices are used to improve airway clearance in individuals with acute respiratory failure. Some MI-E devices measure cough peak flow (CPF) during MI-E to optimize pressure adjustments. The aim was to compare CPF and effective cough volume (ECV: volume expired/coughed > 3 L/s) measurements between 4 MI-E devices under simulated conditions of stable versus collapsed airway., Methods: Four MI-E devices were tested on the bench. Each device was connected via a standard circuit to a collapsible tube placed in an airtight chamber that was attached to a lung model with adjustable compliance and resistance. Pressure was measured upstream and downstream the collapsing tube; air flow was measured between the chamber and the lung model. Each device was tested in 2 conditions: collapse condition (0 cm H 2 O) and no-collapse condition (-70 cm H 2 O). For each condition, 6 combinations of inspiratory/expiratory pressures were applied. CPF was measured at the "mouth level" by the device built-in flow meter and at the "tracheal level" by a dedicated pneumotachograph. Comparisons were performed with non-parametric tests., Results: CPF values measured at the tracheal level and ECV values differed between devices for each inspiratory/expiratory pressure in the collapse and no-collapse conditions ( P < .001). CPF values were significantly lower at the tracheal level in the collapse as compared with the no-collapse condition ( P < .001 for each device), whereas they were higher at the mouth level ( P < .05) for 3 of the 4 devices., Conclusions: CPF values differed significantly across MI-E devices, highlighting limitation(s) of using only CPF values to determine cough effectiveness. In simulated of airway collapse, CPF increased at the mouth, whereas it decreased at the tracheal level., Competing Interests: The authors have disclosed no conflicts of interest., (Copyright © 2023 by Daedalus Enterprises.)

Background: Adaptive servoventilation (ASV) is a recently developed ventilation mode designed to stabilize ventilation in patients with central sleep apnea and Cheyne-Stokes respiration. Alternatively, modes aiming to maintain average ventilation over several breaths, such as average volume-assured pressure support (AVAPS) and intelligent volume-assured pressure support (iVAPS), could be efficient during ventilation instability by reducing central events. These modes are available on a variety of devices. This bench evaluation studied the response of these different modes and devices to simulated transient hypoventilation events., Methods: Three home ventilation devices operating in ASV modes (AirCurve S10 VAuto, ResMed; DreamStation autoSV, Philips; Prisma CR, Löwenstein) and 2 ventilators with the AVAPS mode (DreamStation BiPAP, Philips; Lumis iVAPS, ResMed) were evaluated during transient central hypopnea/hypoventilation simulations characterized by a constant breathing frequency of 15 breaths/min and a progressive decrease of tidal volume (V T ) from 500 mL to 50 mL, in 18, 12, 9, and 6 breaths, respectively, followed by a progressive return to the baseline at the same rate., Results: The AirCurve S10 VAuto reacted to a V T decrease between 80% and 50% of baseline V T . DreamStation BiPAP and Prisma CR reacted when V T decreased to between 60% and 30% of baseline V T , whereas the AVAPS response to hypopnea occurred during the crescendo phase of hypopnea/hypoventilation V T . The iVAPS response was between that of the AirCurve S10 VAuto and the other ASV devices. Among the ASV devices, the minimum V T was higher with AirCurve S10 VAuto, followed by the Prisma CR and the DreamStation BiPAP. Minimum V T was not influenced by AVAPS and was improved by iVAPS without outperforming the AirCurve S10 VAuto. Maximum V T was increased by iVAPS, whereas ASV devices did not induce a significant V T overshoot., Conclusions: ASV devices improved central hypopnea/hypoventilation events without inducing hyperpnea events and therefore were better adapted than AVAPS and iVAPS devices, with notable differences in their responses to hypoventilation events., Competing Interests: The devices used in this study were donated by ASV Santé, which is a home care provider. The authors have disclosed no conflicts of interest., (Copyright © 2020 by Daedalus Enterprises.)

Background: Breath-stacking, which consists of taking 2 or more consecutive ventilator insufflations without exhaling, is a noninvasive and inexpensive cough-assistance technique for patients with neuromuscular disease. Volumetric cough mode (VCM) is a recently introduced ventilator mode consisting of a programmable intermittent deep breath equal to a set percentage of the baseline tidal volume. Here, our objective was to compare VCM to breath-stacking during volume-control continuous mandatory ventilation in subjects on long-term noninvasive mechanical ventilation at home., Methods: We included 20 subjects with neuromuscular disease causing severe respiratory muscle dysfunction with a cough peak flow (CPF) < 270 L/min or maximum expiratory pressure < 45 cm H 2 O. Each subject tested breath-stacking and VCM in random order., Results: CPF increased with both techniques but was higher with VCM than with breath-stacking in 16 subjects. In 17 subjects, CPF was highest with the technique that produced the greatest inspiratory capacity., Conclusion: Our results indicate that both breath-stacking and VCM are useful cough-augmentation techniques. Displaying insufflated volumes on the ventilator screen is a simple and accessible method for selecting the most efficient cough-augmentation technique delivered by a home ventilator., (Copyright © 2019 by Daedalus Enterprises.)

Background: Duchenne muscular dystrophy (DMD) is a sex-linked genetic disorder in which progressive impairment of skeletal muscle function eventually leads to severe respiratory failure requiring continuous noninvasive ventilation (NIV) at home. A current focus of debate is whether NIV may slow the decline in respiratory function or, on the contrary, worsen respiratory function when started early. Our objective here was to describe the effects of NIV on vital capacity (VC) and maximum respiratory pressures in DMD., Methods: We analyzed retrospective data from 71 subjects with DMD, including VC, maximum static respiratory pressures, and sniff nasal inspiratory pressure before and after NIV initiation. The declines in these variables from the highest value to the most recent value were computed., Results: Although respiratory function continued to deteriorate over time, NIV introduction was followed by significant slowing in the annual rates of decline in VC (from 4.28 to 1.36 percent predicted), maximum inspiratory pressure (from 2.77 to 1.48 cm H 2 O), and maximum expiratory pressure (from 2.00 to 1.00 cm H 2 O). NIV had no effect on sniff nasal inspiratory pressure., Conclusions: Introducing NIV in subjects with DMD was followed by slowing of the declines in VC and in maximum static inspiratory and expiratory pressures., (Copyright © 2016 by Daedalus Enterprises.)

Background: Early recognition and an attempt at obtaining microbiological documentation are recommended in patients with non-community-acquired pneumonia (NCAP), whether hospital-acquired (HAP) or health care-associated (HCAP). We aimed to characterize the clinical features and microbial etiologies of NCAP to assess the impact of microbiological investigation on their management., Methods: This was a prospective 1-y study in a university hospital with 141 non-mechanically ventilated subjects suspected of having HAP (n = 110) or HCAP (n = 31)., Results: Clinical criteria alone poorly identified pneumonia (misdiagnosis in 50% of cases). Microbiological confirmation was achievable in 80 subjects (57%). Among 79 microorganisms isolated, 28 were multidrug-resistant aerobic Gram-negative bacilli and group III Enterobacteriaceae and 6 were methicillin-resistant Staphylococcus aureus. Multidrug-resistant aerobic Gram-negative bacilli accounted for one third of the microorganisms in early-onset HAP and for 50% in late-onset HAP. Methicillin-resistant S. aureus was most often recovered from subjects with HCAP. Inappropriate empirical antibiotics were administered to 36% of subjects with confirmed pneumonia. Forty subjects were admitted to the ICU, 13 (33%) of whom died. Overall, 39 subjects (28%) died in the hospital., Conclusions: Integrating the microbiological investigation in the complex clinical diagnostic workup of patients suspected of having NCAP is mandatory. Respiratory tract specimens should be obtained whenever possible for appropriate management., (Copyright © 2016 by Daedalus Enterprises.)

Background: The battery life (BL) of portable home ventilator batteries is reported by manufacturers. The aim of this study was to evaluate the effects of ventilator mode, breathing frequency, PEEP, and leaks on the BL of 5 commercially available portable ventilators., Methods: The effects of the ventilator mode (volume controlled-continuous mandatory ventilation [VC-CMV] vs pressure support ventilation [PSV]), PEEP 5 cm H2O, breathing frequency (10, 15, and 20 breaths/min), and leaks during both volume-targeted ventilation and PSV on the BL of 5 ventilators (Elisée 150, Monnal T50, PB560, Vivo 50, and Trilogy 100) were evaluated. Each ventilator was ventilated with a test lung at a tidal volume of 700 ml and an inspiratory time of 1.2 s in the absence of leaks., Results: Switching from PSV to VC-CMV or the addition of PEEP did not significantly change ventilator BL. The increase in breathing frequency from 10 to 20 breaths/min decreased the BL by 18 ± 11% (P = .005). Leaks were associated with an increase in BL during the VC-CMV mode (18 ± 20%, P = .04) but a decrease in BL during the PSV mode (-13 ± 15%, P = .04)., Conclusions: The BL of home ventilators depends on the ventilator settings. BL is not affected by the ventilator mode (VC-CMV or PSV) or the addition of PEEP. BL decreases with an increase in breathing frequency and during leaks with a PSV mode, whereas leaks increase the duration of ventilator BL during VC-CMV., (Copyright © 2014 by Daedalus Enterprises.)

Background: To maximize the likelihood of successful long-term mechanical ventilation (MV) in patients with neuromuscular diseases, ventilator characteristics and settings must be chosen carefully, taking into account both medical requisites and the patient's preference and comfort., Objectives: To evaluate patients' knowledge about and comfort with their long-term MV; to compare patients' and prescribers' opinions and expectations regarding long-term MV; and to compare the equipment used by the patients to the prescribers' current MV prescription., Methods: Neuromuscular patients receiving long-term MV, and home MV prescribers in Belgium and France were asked to respond to a questionnaire survey specifically developed for the study., Results: Completed questionnaires were collected from 209 patients (mean age 35.4 ± 15.9 y, range 3-86 y), ventilated since 11 ± 17 year, and 45 MV prescribers. One hundred sixty-three (78%) patients correctly designated their MV mode as a volume or pressure controlled mode. When an inspiratory trigger was available, 92% of the patients were able to use it, but only 69% were satisfied. Prescribers were more prone than patients to use new technologies such as an emergency-release system for the noninvasive interface (1-10 visual analog scale score 9.2 ± 1.5 vs 6.8 ± 3.3, P < .001), a humidification system (8.6 ± 1.4 vs 7.8 ± 2.6, P = .02), a contactor for providing larger inspiratory volumes (8.4 ± 1.7 vs 6.0 ± 3.0, P = .009), a built-in cough assistance mode (9.2 ± 1.4 vs 5.5 ± 3.5, P < .001), new options to improve speech, or new MV modes such as a volume-targeted pressure control., Conclusions: The opinions of patients and prescribers differed about the ideal home ventilator. Patients were less prone to use new technologies, mainly because of a lack of information, underlining the need for regular MV update in patients receiving long-term MV.

Objective: To determine whether optoelectronic plethysmography accurately evaluated vital capacity (VC) in patients with respiratory muscle dysfunction of variable severity, including those with paradoxical abdominal movements., Methods: In 20 subjects, VC was measured in the supine position using both spirometry and optoelectronic plethysmography (6 optoelectronic cameras and 52 reflective markers on the anterior chest wall)., Results: Spirometry VC (VC-Spiro) correlated positively with optoelectronic VC (VC-Opto) (r(2) = 0.99, P < .001), and the regression line was very close to the identity line (VC-Opto [mL] = -1.202 + 1.007 × VC-Spiro [mL]). A Bland-Altman plot showed that the mean difference was -20 mL (95% CI -63 mL to 24 mL) and the limits of agreement were 163 mL (95% CI 106 mL to 231 mL) and -203 mL (95% CI -271 mL to -146 mL). The difference between the 2 values expressed as the percentage of the mean value was < 15% in all 20 subjects, < 10% in 17 (85%) subjects, and < 5% in 11 (55%) subjects. The difference, expressed as the percentage of the mean value, was unrelated to the contribution of abdominal motion to VC (r = 0.02 and P = .94), but was significantly related to body mass index (r = 0.53, P = .02)., Conclusions: Optoelectronic plethysmography is accurate and suitable for VC measurement in patients with various degrees of respiratory failure, including those with paradoxical abdominal movements. This noninvasive method may be an attractive alternative for accurately measuring VC in the event of air leakage (through the mouth or tracheostomy) or when patients are unable to breathe with the dead space added by the spirometer.

Background: Pulse oximetry alone has been suggested to determine which patients on home mechanical ventilation (MV) require further investigation of nocturnal gas exchange. In patients with neuromuscular diseases, alveolar hypoventilation (AH) is rarely accompanied with ventilation-perfusion ratio heterogeneity, and, therefore, oximetry may be less sensitive for detecting AH than in patients with lung disease., Objective: To determine whether pulse oximetry (S(pO(2))) and transcutaneous carbon dioxide (P(tcCO(2))) during the same night were interchangeable or complementary for assessing home MV efficiency in patients with neuromuscular diseases., Methods: Data were collected retrospectively from the charts of 58 patients with chronic neuromuscular respiratory failure receiving follow-up at a home MV unit. S(pO(2)) and P(tcCO(2)) were recorded during a 1-night hospital stay as part of standard patient care. We compared AH detection rates by P(tcCO(2)), S(pO(2)), and both., Results: AH was detected based on P(tcCO(2)) alone in 24 (41%) patients, and based on S(pO(2)) alone with 3 different cutoffs in 3 (5%), 8 (14%), and 13 (22%) patients, respectively. Using both P(tcCO(2)) and S(pO(2)) showed AH in 25 (43%) patients., Conclusions: Pulse oximetry alone is not sufficient to exclude AH when assessing home MV efficiency in patients with neuromuscular diseases. Both P(tcCO(2)) and S(pO(2)) should be recorded overnight as the first-line investigation in this population., (Copyright 2012 Daedalus Enterprises)

Objective: To compare conventional tracheotomy with endotracheal intubation to tracheotomy with noninvasive positive-pressure ventilation (NPPV) in advanced neuromuscular disease., Methods: This was a retrospective study of a historical cohort of patients tracheotomized while sedated and intubated versus patients tracheotomized under NPPV and local anesthesia. We recorded previous intubation difficulties, complications (eg, aspiration pneumonia), and hospital stay., Results: Conventional tracheotomy was performed in 7 patients. We performed tracheotomy during NPPV with local anesthesia in 13 patients. All but 3 patients had risk factors for difficult intubation. Hospital stay was 23.3 +/- 10.3 d in the conventional group and 25.3 +/- 12.9 d in the NPPV group (p = 0.87). The number of pneumonias was higher in the conventional-tracheotomy group (4 vs 1, p = 0.03)., Conclusion: In neuromuscular patients, performing tracheotomy with NPPV and local anesthesia may help avoid endotracheal intubation and reduce morbidity.