Document Detail


Alveolar recruitment versus hyperinflation: A balancing act.
MedLine Citation:
PMID:  17093370     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
PURPOSE OF REVIEW: To address lung recruitment according to pressure/volume curves, along with regional recruitment versus hyperinflation evidence from computed tomography and electrical impedance tomography. RECENT FINDINGS: Cyclical tidal volume recruitment of atelectatic lung regions causes acute lung injury, as do large breaths during pneumonectomy. Using the lower inflection point on the static pressure/volume inflation curve plus 2 cmH2O as a positive end-expiratory pressure setting limits hyperinflation in acute lung injury, but may not provide enough positive end-expiratory pressure to avoid cyclical recruitment/derecruitment injury in more severe acute lung injury regions. Both computed tomography and electrical impedance tomography can help titrate positive end-expiratory pressure in these regions, thereby assuring an 'open lung' ventilatory pattern. Regional pressure/volume curves show that adequate positive end-expiratory pressure for severe acute lung injury regions may not be reliably determined from whole lung pressure/volume curves. Balancing positive end-expiratory pressure requires both arterial PO2 and PCO2 values to determine at what level hyperinflated regions become seriously underperfused (develop very high ventilation-perfusion ratios), adding to the hypercarbia from increased deadspace. SUMMARY: Positive end-expiratory pressure levels must be high enough to minimize recruitment/derecruitment cycling. Balancing recruitment versus overdistension may require thoracic tomography, to assure sufficient improvement in oxygenation while limiting hypercarbia.
Authors:
Ron Dueck
Publication Detail:
Type:  Journal Article; Review    
Journal Detail:
Title:  Current opinion in anaesthesiology     Volume:  19     ISSN:  0952-7907     ISO Abbreviation:  Curr Opin Anaesthesiol     Publication Date:  2006 Dec 
Date Detail:
Created Date:  2006-11-09     Completed Date:  2007-02-15     Revised Date:  2008-11-21    
Medline Journal Info:
Nlm Unique ID:  8813436     Medline TA:  Curr Opin Anaesthesiol     Country:  United States    
Other Details:
Languages:  eng     Pagination:  650-4     Citation Subset:  IM    
Affiliation:
Department of Anesthesiology, University of California, San Diego, California, USA. rdueck@ucsd.edu
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MeSH Terms
Descriptor/Qualifier:
Animals
Continuous Positive Airway Pressure / adverse effects
High-Frequency Ventilation / adverse effects
Humans
Lung Volume Measurements
Plethysmography, Impedance / methods
Positive-Pressure Respiration / adverse effects
Pulmonary Alveoli / physiopathology*,  radiography
Pulmonary Atelectasis / physiopathology*,  radiography,  therapy
Respiration, Artificial* / adverse effects
Respiratory Distress Syndrome, Adult / physiopathology*,  radiography,  therapy
Respiratory Mechanics
Tidal Volume
Tomography, X-Ray Computed / methods

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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