Time Course and Mechanisms of Lung-volume Increase with PEEP in Acute Pulmonary Failure

Katz, Jeffrey A.; Ozanne, G; Zinn, Steven E.; Fairley, H. B.

doi:10.1097/00000542-198101000-00003

Cited by 163 publications

(78 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…169 Effective lung recruitment requires a combination of pressure and time, with time mostly reflecting the influence of airway closure and stress-relaxation (tissue yielding) characteristics of the lung and chest wall. 170 Reopening collapsed small airways is a dynamic process with a variable time course. 171 To recruit collapsed small airways, applied airway pressure must overcome the surface tension, viscosity, and film thickness of the airway lining fluid, which in turn is influenced by airway radius, axial wall traction exerted by the surrounding alveoli, and the presence of functional surfactant.…”

Section: Incorporating Pp Into Bundled Carementioning

confidence: 99%

A Comprehensive Review of Prone Position in ARDS

2015

View full text Add to dashboard Cite

Prone position (PP) has been used since the 1970s to treat severe hypoxemia in patients with ARDS because of its effectiveness at improving gas exchange. Compared with the supine position (SP), placing patients in PP effects a more even tidal volume distribution, in part, by reversing the vertical pleural pressure gradient, which becomes more negative in the dorsal regions. PP also improves resting lung volume in the dorsocaudal regions by reducing the superimposed pressure of both the heart and the abdomen. In contrast, pulmonary perfusion remains preferentially distributed to the dorsal lung regions, thus improving overall alveolar ventilation/perfusion relationships. 1660RESPIRATORY CARE • NOVEMBER 2015 VOL 60 NO 11Moreover, the larger tissue mass suspended from a wider dorsal chest wall effects a more homogeneous distribution of pleural pressures throughout the lung that reduces abnormal strain and stress development. This is believed to ameliorate the severity or development of ventilator-induced lung injury and may partly explain why PP reduces mortality in severe ARDS. Over 40 years of clinical trials have consistently reported improved oxygenation in approximately 70% of subjects with ARDS. Early initiation of PP is more likely to improve oxygenation than initiation during the subacute phase. Maximal oxygenation improvement occurs over a wide time frame ranging from several hours to several days. Meta-analyses of randomized controlled trials suggest that PP provides a survival advantage only in patients with relatively severe ARDS (P aO 2 /F IO 2 <150 mm Hg). Moreover, survival is enhanced when patients are managed with a smaller tidal volume (<8 mL/kg), higher PEEP (10 -13 cm H 2 O), and longer duration of PP sessions (>10 -12 h/session). Combining adjunctive therapies (high PEEP, recruitment maneuvers, and inhaled vasodilators) with PP has an additive effect in improving oxygenation and may be particularly helpful in stabilizing gas exchange in very severe ARDS.

show abstract

Section: Incorporating Pp Into Bundled Carementioning

confidence: 99%

A Comprehensive Review of Prone Position in ARDS

2015

View full text Add to dashboard Cite

show abstract

“…The physiological mechanisms by which CPAP increases FRC are thought to be through a progressively increasing alveolar volume with increases in applied positive end expiratory pressure [47,48], a time dependent increase in lung volume somewhat like pressure/volume hysteresis [47] and increased transpulmonary pressure at end expiration favouring recruitment of collapsed alveoli [49] possibly through collateral channels [50]. DUGGIN et al [51] also postulate that its application may cause a release of prostaglandins into alveolar ducts which act to relax smooth muscle and increase lung volume.…”

Section: Physiological Effectsmentioning

confidence: 99%

“…There are no other reports which investigate the time course of the acute and carry over effects of intermittent CPAP following abdominal surgery. In¯uences on lung volume, of application and removal of positive endexpiratory pressure (PEEP) have been reported to follow a time course of <1 min [47] However, the carry over effects of PEEP and CPAP may be in¯uenced by many contributing factors, including patient pathology and the existing relationship between their closing volume and FRC at the time of measurement.…”

Section: Ef®cacymentioning

confidence: 99%

The use of positive pressure devices by physiotherapists

Denehy

Berney²

2001

Eur Respir J

View full text Add to dashboard Cite

The aim of this paper is to review the indications for use by physiotherapists, such as physiological rationale and the comparative efficacy of intermittent positive pressure breathing (IPPB) and continuous positive airway pressure (CPAP). A brief discussion of nasal intermittent positive airway pressure is also included.The use of IPPB for post operative prophylaxis has not been supported in the literature. In patients with low lung volumes resulting from neuromuscular disease or spinal injury, IPPB may be useful in the acute phase to improve tidal volume and cough effectiveness.The physiological benefits of CPAP to improve lung volumes are well documented in the literature. Physiotherapists use CPAP as an intermittent application in patients with low lung volumes following surgery. It is predominantly used as a second line intervention in the presence of refractory atelectasis and poor gas exchange. It may also be indicated in other patient groups with similar physiological problems.Nasal intermittent positive airway pressure combines the beneficial effects of intermittent positive pressure breathing and continuous positive airway pressure. There have been many studies evaluating its effectiveness. These have been supportive for patients with neuromuscular disease and sleep disordered breathing, but more research is needed in patients with acute respiratory failure.

show abstract

“…Perhaps its origins were rooted in anesthetic rather than intensive care practice. As already noted, as many as 10 breathing cycles spanning approximately that long may be needed to realize the full benefit from a step change in low-level PEEP in normal anesthetized subjects [4]. Although the partially collapsed lungs of experimental animals tend to open in a series of avalanches, the cumulative duration of the high-pressure phase of these cycles is not lengthy [8].…”

mentioning

confidence: 98%

“…At relatively low tidal pressures, multiple tidal cycles must be delivered after a step change in PEEP before the functional residual capacity (FRC) stabilizes at its final higher value [4]. However, although exposure time is clearly a component of the recruiting process, time of application is not an equal partner with airway pressure; of the two, pressure is clearly the more important variable.…”

mentioning

confidence: 99%

Recruitment by sustained inflation: time for a change

Marini

2011

Intensive Care Med

View full text Add to dashboard Cite

Time Course and Mechanisms of Lung-volume Increase with PEEP in Acute Pulmonary Failure

Cited by 163 publications

References 0 publications

A Comprehensive Review of Prone Position in ARDS

A Comprehensive Review of Prone Position in ARDS

The use of positive pressure devices by physiotherapists

Recruitment by sustained inflation: time for a change

Contact Info

Product

Resources

About