Effects of positive end-expiratory pressure on respiratory function and hemodynamics in patients with acute respiratory failure with and without intra-abdominal hypertension: a pilot study.

Abstract

INTRODUCTION:

To investigate the effects of positive end-expiratory pressure (PEEP) on respiratory function and hemodynamics in patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) with normal intra-abdominal pressure (IAP < 12 mmHg) and with intra-abdominal hypertension (IAH, defined as IAP >or= 12 mmHg) during lung protective ventilation and a decremental PEEP, a prospective, observational clinical pilot study was performed.

METHODS:

Twenty patients with ALI/ARDS with normal IAP or IAH treated in the surgical intensive care unit in a university hospital were studied. The mean IAP in patients with IAH and normal IAP was 16 +/- 3 mmHg and 8 +/- 3 mmHg, respectively (P < 0.001). At different PEEP levels (5, 10, 15, 20 cmH2O) we measured respiratory mechanics, partitioned into its lung and chest wall components, alveolar recruitment, gas-exchange, hemodynamics, extravascular lung water index (EVLWI) and intrathoracic blood volume index (ITBVI).

RESULTS:

We found that ALI/ARDS patients with IAH, as compared to those with normal IAP, were characterized by: a) no differences in gas-exchange, respiratory mechanics, partitioned into its lung and chest wall components, as well as hemodynamics and EVLWI/ITBVI; b) decreased elastance of the respiratory system and the lung, but no differences in alveolar recruitment and oxygenation or hemodynamics, when PEEP was increased at 10 and 15cmH2O; c) at higher levels of PEEP, EVLWI was lower in ALI/ARDS patients with IAH as compared with those with normal IAP.

CONCLUSIONS:

IAH, within the limits of IAP measured in the present study, does not affect interpretation of respiratory mechanics, alveolar recruitment and hemodynamics.

• Authors: Joerg Krebs, Paolo Pelosi, Charalambos Tsagogiorgas, Markus Alb, Thomas Luecke
• Journal: Critical care (London, England) (Crit Care) Vol. 13 Issue 5 Pg. R160 ( 2009) ISSN: 1466-609X [Electronic] England
• PMID: 19804634 (Publication Type: Journal Article)

Topics

• Abdomen (physiopathology)
• Acute Lung Injury (physiopathology, therapy)
• Aged
• Compartment Syndromes
• Female
• Hemodynamics (physiology)
• Humans
• Hypertension (diagnosis, physiopathology)
• Intensive Care Units
• Male
• Middle Aged
• Observation
• Pilot Projects
• Positive-Pressure Respiration
• Prospective Studies
• Respiratory Distress Syndrome (physiopathology, therapy)
• Respiratory Mechanics (physiology)
• Respiratory Physiological Phenomena