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Volume assured pressure support ventilation – Induced arousals
Sleep Medicine 13 (2012) 767–768
Contents lists available at SciVerse ScienceDirect
Sleep Medicine journal homepage: www.elsevier.com/locate/sleep
Images in Sleep Medicine
Volume assured pressure support ventilation – Induced arousals Annalisa Carlucci a,⇑, Francesco Fanfulla b, Marco Mancini a, Stefano Nava c a
Respiratory Intensive Care Unit, Fondazione S. Maugeri, IRCCS, Pavia, Italy Sleep Medicine, Fondazione S. Maugeri, IRCCS, Pavia, Italy c Respiratory and Critical Care Unit, S. Orsola-Malpighi Hospital, Bologna, Italy b
1. Introduction to the case Volume assured ventilation is a hybrid mode of ventilation that assures a defined pre-set tidal volume (Vtg) during pressure support ventilation. This is achieved by varying the inspiratory pressure in consecutive breaths by an increase proportionate to the difference between the set and estimated tidal volumes. This mode of ventilation is proposed to correct nocturnal hypoventilation
[1–3]. A 39-year old, overweight man (BMI = 29) affected by cerebellar atrophy and spinal cord disease received home non-invasive ventilation (NIV) because of diurnal hypercapnia (PaCO2 = 68 mm Hg, PaO2 = 55 mm Hg and pH 7.37), daytime sleepiness, and fatigue. A standard baseline polysomnogram showed the presence of an obstructive sleep apnoea and hypoventilation, with severe nocturnal hypoxia, mainly during the rapid eye movement (REM) stage of sleep: apnea-hypopnea index (AHI) of 32; mean SpO2
Fig. 1. From top to bottom: F4-A1; C4-A1; O2-A1; EOGleft; EOGright; EMGchin; EKG; EMG tibialis anterior left; respiratory flow (l/min); mask pressure (cm H2O); thoracic respirogram; abdominal respirogram; SpO2 (%); heart rate; body position. Time scale: Upper part (neurophysiological signals) 60 s; lower part (respiratory signals) 120 s. Square on the EEG signals indicates an arousal associated with an abrupt increase of inspiratory pressure (black arrows on mask pressure signal). The total arousal index was 22, the majority of the arousals (56.8%) being associated with an abrupt increase of inspiratory pressure even within two breaths up to 10 cm H2O. During volume assured ventilation the arousal index was 12.9, 54.3% of them following residual oxygen desaturations.
⇑ Corresponding author. Address: Respiratory Intensive Care Unit, Fondazione S. Maugeri, IRCCS, Via Maugeri, 10, Pavia, Italy. Fax: +39 0382 592075. E-mail address: [email protected] (A. Carlucci). 1389-9457/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.sleep.2012.02.006
768
A. Carlucci et al. / Sleep Medicine 13 (2012) 767–768
Fig. 2. Hypnogram of an oxygen saturation (SpO2%) related to the sleep study during volume assured ventilation (a) and APCV (b) ventilation.
87%; time spent with an SpO2 < 90% (T90) of 78% of total sleep time; oxygen desaturation index (ODI) of 51. Nocturnal ventilation with a volume assured (Idea Ultra – Saime) was prescribed with the following settings: pressure support of 10 cm H2O, expiratory positive airway pressure of 10 cm H2O, Vtg of 0.45 L, inspiratory pressure limitation of 30 cm H2O. One-year later the patient was referred to our unit owing to persistent sleep fragmentation and diurnal somnolence, despite an improvement in arterial gases: PaO2 73.3 mm Hg, PaCO2 49 mm Hg, pH 7.37.
increase the level of inspiratory support up to 10 cm H2O within one breath. Although five trials have compared the volume assured ventilation with standard modes of ventilation [1–5], none assessed the effect of the different algorithms on sleep structure. This report highlights a possible risk of sleep fragmentation during volume assured ventilation, especially when a sudden increase of inspiratory pressure occurs.
2. Image analysis
The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: doi:10.1016/j.sleep.2012.02.006.
A full standard polysomnogram showed repetitive arousals chiefly associated with an abrupt increase of inspiratory pressure of 10 cm H2O in a single breath or in two consecutive breaths (Fig. 1). The gas exchange showed an improvement (mean SpO2 93.5%, T90 1.2%), with persistent but shallower desaturations (ODI 53.3). Sleep quality and diurnal symptoms improved after starting Assisted Pressure Control Ventilation (APCV) without volume assured (Fig. 2). No differences in arterial blood gases were detected. 3. Discussion Currently, volume assured ventilation is a mode of ventilation available in most home ventilators. It aims to stabilize delivered volume during sleep by continuous adjustment of inspiratory support. However, the algorithms used to assure the set Vtg differ considerably between manufacturers: the main difference between the algorithms concerns the time needed to reach the target volume. Specifically, the ventilator used by the patient may
Conflict of Interest
References [1] Storre JH, Seuthe B, Fiechter R, Milioglou S, Dreher M, Sorichter S, et al. Crossover trial in obesity hypoventilation: a randomized average volumeassured pressure support. Chest 2006;130:815–21. [2] Janssens JP, Metzger M, Sforza E. Impact of volume targeting on efficacy of bilevel non-invasive ventilation and sleep in obesity-hypoventilation. Respir Med 2009;103:165–72. [3] Crescimanno G, Marrone O, Vianello A. Efficacy and comfort of volume guaranteed pressure support in patients with chronic ventilatory failure of neuromuscular origin. Respirology 2011;16:672–9. [4] Crisafulli E, Manni G, Kidonias M, Trianni L, Clini EM. Subjective sleep quality during average volume assured pressure support (AVAPS) ventilation in patients with hypercapnic COPD: a physiological pilot study. Lung 2009;187:299–305. [5] Oscroft NS, Ali M, Gulati A, Davies MG, Quinnell TG, Shneerson JM, et al. A randomised crossover trial comparing volume assured and pressure presetnon-invasive ventilation in stable hypercapnic COPD. COPD 2010;7:398–403.
Contents lists available at SciVerse ScienceDirect
Sleep Medicine journal homepage: www.elsevier.com/locate/sleep
Images in Sleep Medicine
Volume assured pressure support ventilation – Induced arousals Annalisa Carlucci a,⇑, Francesco Fanfulla b, Marco Mancini a, Stefano Nava c a
Respiratory Intensive Care Unit, Fondazione S. Maugeri, IRCCS, Pavia, Italy Sleep Medicine, Fondazione S. Maugeri, IRCCS, Pavia, Italy c Respiratory and Critical Care Unit, S. Orsola-Malpighi Hospital, Bologna, Italy b
1. Introduction to the case Volume assured ventilation is a hybrid mode of ventilation that assures a defined pre-set tidal volume (Vtg) during pressure support ventilation. This is achieved by varying the inspiratory pressure in consecutive breaths by an increase proportionate to the difference between the set and estimated tidal volumes. This mode of ventilation is proposed to correct nocturnal hypoventilation
[1–3]. A 39-year old, overweight man (BMI = 29) affected by cerebellar atrophy and spinal cord disease received home non-invasive ventilation (NIV) because of diurnal hypercapnia (PaCO2 = 68 mm Hg, PaO2 = 55 mm Hg and pH 7.37), daytime sleepiness, and fatigue. A standard baseline polysomnogram showed the presence of an obstructive sleep apnoea and hypoventilation, with severe nocturnal hypoxia, mainly during the rapid eye movement (REM) stage of sleep: apnea-hypopnea index (AHI) of 32; mean SpO2
Fig. 1. From top to bottom: F4-A1; C4-A1; O2-A1; EOGleft; EOGright; EMGchin; EKG; EMG tibialis anterior left; respiratory flow (l/min); mask pressure (cm H2O); thoracic respirogram; abdominal respirogram; SpO2 (%); heart rate; body position. Time scale: Upper part (neurophysiological signals) 60 s; lower part (respiratory signals) 120 s. Square on the EEG signals indicates an arousal associated with an abrupt increase of inspiratory pressure (black arrows on mask pressure signal). The total arousal index was 22, the majority of the arousals (56.8%) being associated with an abrupt increase of inspiratory pressure even within two breaths up to 10 cm H2O. During volume assured ventilation the arousal index was 12.9, 54.3% of them following residual oxygen desaturations.
⇑ Corresponding author. Address: Respiratory Intensive Care Unit, Fondazione S. Maugeri, IRCCS, Via Maugeri, 10, Pavia, Italy. Fax: +39 0382 592075. E-mail address: [email protected] (A. Carlucci). 1389-9457/$ - see front matter Ó 2012 Elsevier B.V. All rights reserved. doi:10.1016/j.sleep.2012.02.006
768
A. Carlucci et al. / Sleep Medicine 13 (2012) 767–768
Fig. 2. Hypnogram of an oxygen saturation (SpO2%) related to the sleep study during volume assured ventilation (a) and APCV (b) ventilation.
87%; time spent with an SpO2 < 90% (T90) of 78% of total sleep time; oxygen desaturation index (ODI) of 51. Nocturnal ventilation with a volume assured (Idea Ultra – Saime) was prescribed with the following settings: pressure support of 10 cm H2O, expiratory positive airway pressure of 10 cm H2O, Vtg of 0.45 L, inspiratory pressure limitation of 30 cm H2O. One-year later the patient was referred to our unit owing to persistent sleep fragmentation and diurnal somnolence, despite an improvement in arterial gases: PaO2 73.3 mm Hg, PaCO2 49 mm Hg, pH 7.37.
increase the level of inspiratory support up to 10 cm H2O within one breath. Although five trials have compared the volume assured ventilation with standard modes of ventilation [1–5], none assessed the effect of the different algorithms on sleep structure. This report highlights a possible risk of sleep fragmentation during volume assured ventilation, especially when a sudden increase of inspiratory pressure occurs.
2. Image analysis
The ICMJE Uniform Disclosure Form for Potential Conflicts of Interest associated with this article can be viewed by clicking on the following link: doi:10.1016/j.sleep.2012.02.006.
A full standard polysomnogram showed repetitive arousals chiefly associated with an abrupt increase of inspiratory pressure of 10 cm H2O in a single breath or in two consecutive breaths (Fig. 1). The gas exchange showed an improvement (mean SpO2 93.5%, T90 1.2%), with persistent but shallower desaturations (ODI 53.3). Sleep quality and diurnal symptoms improved after starting Assisted Pressure Control Ventilation (APCV) without volume assured (Fig. 2). No differences in arterial blood gases were detected. 3. Discussion Currently, volume assured ventilation is a mode of ventilation available in most home ventilators. It aims to stabilize delivered volume during sleep by continuous adjustment of inspiratory support. However, the algorithms used to assure the set Vtg differ considerably between manufacturers: the main difference between the algorithms concerns the time needed to reach the target volume. Specifically, the ventilator used by the patient may
Conflict of Interest
References [1] Storre JH, Seuthe B, Fiechter R, Milioglou S, Dreher M, Sorichter S, et al. Crossover trial in obesity hypoventilation: a randomized average volumeassured pressure support. Chest 2006;130:815–21. [2] Janssens JP, Metzger M, Sforza E. Impact of volume targeting on efficacy of bilevel non-invasive ventilation and sleep in obesity-hypoventilation. Respir Med 2009;103:165–72. [3] Crescimanno G, Marrone O, Vianello A. Efficacy and comfort of volume guaranteed pressure support in patients with chronic ventilatory failure of neuromuscular origin. Respirology 2011;16:672–9. [4] Crisafulli E, Manni G, Kidonias M, Trianni L, Clini EM. Subjective sleep quality during average volume assured pressure support (AVAPS) ventilation in patients with hypercapnic COPD: a physiological pilot study. Lung 2009;187:299–305. [5] Oscroft NS, Ali M, Gulati A, Davies MG, Quinnell TG, Shneerson JM, et al. A randomised crossover trial comparing volume assured and pressure presetnon-invasive ventilation in stable hypercapnic COPD. COPD 2010;7:398–403.