Titration of tidal volume and induced hypercapnia in acute respiratory distress syndrome.

Roupie, É.; Dambrosio, Michele; Servillo, Giuseppe; Mentec, Hervé; Atrous, Souheil El; Beydon, L.; Brun‐Buisson, C.; Lemaire, François; Brochard, Laurent

doi:10.1164/ajrccm.152.1.7599810

Cited by 295 publications

(167 citation statements)

References 31 publications

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“…When PEEP was set according to the super syringe measurement [21] and ordinary tidal volumes were used, a notable nonlinearity of the Pel,st-V curve was observed. Similar observations have been regarded as evidence of lung overdistension [34]. In COPD, PEEP caused neither a significant displacement of the Pel,st-V curve nor an increase of compliance.…”

Section: Static Elastic Recoilsupporting

confidence: 68%

Respiratory mechanics in patients ventilated for critical lung disease

Beydon¹,

Svantesson²,

Brauer³

et al. 1996

Eur Respir J

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Respiratory mechanics, using flow interruption, was previously studied during the complete breath in healthy ventilated man, with numerical techniques relieving constraints regarding flow pattern. The classical linear model of nonNewtonian behaviour was found to be valid. The present study was extended to subjects with critical lung disease.Subjects with acute lung injury (ALI; n=2), acute respiratory distress syndrome (ARDS; n=4), and chronic obstructive pulmonary disease (COPD; n=3) were studied with and without positive end-expiratory pressure (PEEP). Functional residual capacity (FRC) was measured with sulphur hexafluoride (SF 6 ) wash-out.The static pressure-volume (P-V) curve was linear at zero end-expiratory pressure (ZEEP), but nonlinear at PEEP. Its hysteresis was nonsignificant. In ALI/ ARDS, PEEP increased lung volume by distension and recruitment, but only by distension in COPD. In ALI/ARDS, resistance was increased, at ZEEP. In COPD, resistance became extremely high during expiration at ZEEP. In ALI/ARDS at ZEEP, non-Newtonian behaviour, representing tissue stress relaxation and pendelluft, complied with the classical linear model. At PEEP, the non-Newtonian compliance became volume-dependent to an extent correlated to the nonlinearity of the static P-V curve. In COPD, non-Newtonian behaviour was adequately explained only with a model with different inspiratory and expiratory behaviour.The classical model of the respiratory system is valid in ALI/ARDS at ZEEP. More advanced models are needed at PEEP and in COPD. Eur Respir J., 1996, 9, 262-273 The flow interruption method has been used for studies both in ventilated humans and animals. The analysis has been based on a classical model. This model includes a Newtonian resistor (R) representing mainly airway resistance [1], a Newtonian capacitor (C) representing the static pressure-volume (P-V) relationship and a unit, that comprises a resistor (Rve) and a capacitor (Cve) ( fig. 1), which reflects non-Newtonian behaviour due to ventilation inhomogeneity (pendelluft) and tissue viscoelasticity (stress adaptation). It is well-known that these two phenomena cannot be distinguished on the basis of pressure and flow measured at the airway opening [1,2]. It will be discussed below that Rve and Cve probably represent tissue viscoelasticity to a greater extent than pendelluft in the present context. Rve and Cve will together be denoted the viscoelastic unit, to be considered in a broad sense. Due to methodological limitations, most studies have been limited to inspiration and constant flow [2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Recently, we modified the flow interruption technique to improve accuracy of data acquisition and analysis [17]. Rve and Cve were estimated with a numerical iterative method. This method is not limited to a particular flow pattern. This enabled an analysis of the complete respiratory cycle. In normal subjects, the static P-V curve was linear. The static P-V curve did not show any hysteresis over the tidal volume...

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Section: Static Elastic Recoilsupporting

confidence: 68%

Respiratory mechanics in patients ventilated for critical lung disease

Beydon¹,

Svantesson²,

Brauer³

et al. 1996

Eur Respir J

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“…Given this high slope, a small increment in pressure generated by low PS generates in turn a large change in volume. The higher the PEEP needed to keep the lung above closing volume, the smaller the tidal volume needs to be [51,115] (Fig. 2 in [114]).…”

Section: Analysis Of the Blood Gasesmentioning

confidence: 99%

“…Although this has been accepted throughout this article, this requires evidence-based demonstration, irrespective of the use of CMV vs. SV. (50) is set (Vt ≤ 5 mL kg −1 [51]); this implies lowering the VO 2 . Then, the PEEP is increased to Pplat = 30 cm H 2 0.…”

Section: Extubationmentioning

confidence: 99%

“…1 in [65]) is now optimized and includes a high PEEP [62,66], a Pplat that is as low as possible [51,67] (Fig. 2 in [51 O or Vt ≈ 6 mL kg −1 ) lead to a high PEEP and low driving pressure only for the time necessary to stabilize a sick patient ("Friday night ventilation" [11]) and to differentiate focal vs. diffuse ARDS [75,76].…”

Section: Controlled Mechanical Ventilation: "Protective" Ventilationmentioning

confidence: 99%

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Early severe acute respiratory distress syndrome: What’s going on? Part II: controlled vs. spontaneous ventilation?

Petitjeans

Pichot

Ghignone

et al. 2016

Anaesthesiol Intensive Ther

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The second part of this overview on early severe ARDS delineates the pros and cons of the following: a) controlled mechanical ventilation (CMV: lowered oxygen consumption and perfect patient-to-ventilator synchrony), to be used during acute cardio-ventilatory distress in order to "buy time" and correct circulatory insufficiency and metabolic defects (acidosis, etc.); b) spontaneous ventilation (SV: improved venous return, lowered intrathoracic pressure, absence of muscle atrophy). Given a stabilized early severe ARDS, as soon as the overall clinical situation improves, spontaneous ventilation will be used with the following stringent conditionalities: upfront circulatory optimization, upright positioning, lowered VO 2 , lowered acidotic and hypercapnic drives, sedation without ventilatory depression and without lowered muscular tone, as well as high PEEP (titrated on transpulmonary pressure, or as a second best: "trial"-PEEP) with spontaneous ventilation + pressure support (or newer modes of ventilation). As these propositions require evidence-based demonstration, the reader is reminded that the accepted practice remains, in 2016, controlled mechanical ventilation, muscle relaxation and prone position. Anestezjologia Intensywna Terapia 2016, tom 48, nr 5, 354-366Key words: acute respiratory distress syndrome, ARDS, severe ARDS; acute hypoxic non-hypercapnic respiratory failure; driving pressure; tidal volume, Vt, low tidal volume, ultra-low tidal volume; positive end-expiratory pressure, PEEP; transpulmonary pressure; controlled mechanical ventilation; spontaneous ventilation; spontaneous breathing; pressure support, airway pressure release ventilation; sedation, cooperative sedation; alpha-2 adrenergic agonist, clonidine, dexmedetomidineThe previous chapter overviewed, for residents rotating through the critical care unit (CCU), basic pathophysiology required to analyze early severe acute respiratory distress syndrome (ARDS). An emphasis was placed on spontaneous ventilation both in the setting of the healthy volunteer and of severe ARDS. This chapter will address the pros and cons of controlled mechanical ventilation, with the help of muscle relaxation, as opposed to the putative advantages of spontaneous ventilation. So far, spontaneous ventilation has not achieved evidence-based demonstration: thus, as in part I, conjectures are within [….], following [1]. i. MUSCLE RELAXATiON VERSUS SPONTANEOUS VENTiLATiON?When muscle relaxation is considered, the overall picture appears to be simplified with 48 h of muscle relaxation [2]. A sober interpretation may be considered. a. Muscle relaxationIn severe ARDS (P/F < 120), muscle relaxation [2] lowered the mortality (45 to 31%; difference of −32%; P = 0.04), multiple organ failure (MOF), and barotrauma and led to more ventilator-free days and identical CCU-acquired paresis. Muscle relaxation was hypothesized to minimize excessive transpulmonary pressure, patient-to-ventilator asynchrony [2], ventilator-induced lung injury (VILI), atelectrauma, overdistension,...

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“…6B). The LIP was considered to be the pressure level at which massive alveolar recruitment occurs (Jonson and Svantesson, 1999); UIP was considered to be the pressure level indicating alveolar overdistension (Roupie et al, 1995). In consequence, a ventilation strategy was developed to keep the lung open (by setting PEEP above LIP) and to minimize overdistension (by restricting V t such that peak pressure is smaller than UIP) (Takeuchi et al, 2002).…”

Section: Optimizing Peep With Lung Mechanicsmentioning

confidence: 99%