Document Detail

Relation of the static compliance curve and positive end-expiratory pressure to oxygenation during one-lung ventilation.
MedLine Citation:
PMID:  11684977     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Positive end-expiratory pressure (PEEP) is commonly applied to the ventilated lung to try to improve oxygenation during one-lung ventilation but is an unreliable therapy and occasionally causes arterial oxygen partial pressure (PaO(2)) to decrease further. The current study examined whether the effects of PEEP on oxygenation depend on the static compliance curve of the lung to which it is applied. METHODS: Forty-two adults undergoing thoracic surgery were studied during stable, open-chest, one-lung ventilation. Arterial blood gases were measured during two-lung ventilation and one-lung ventilation before, during, and after the application of 5 cm H(2)O PEEP to the ventilated lung. The plateau end-expiratory pressure and static compliance curve of the ventilated lung were measured with and without applied PEEP, and the lower inflection point was determined from the compliance curve. RESULTS: Mean (+/- SD) PaO(2) values, with a fraction of inspired oxygen of 1.0, were not different during one-lung ventilation before (192 +/- 91 mmHg), during (190 +/- 90), or after ( 205 +/- 79) the addition of 5 cm H(2)O PEEP. The mean plateau end-expiratory pressure increased from 4.2 to 6.8 cm H(2)O with the application of 5 cm H(2)O PEEP and decreased to 4.5 cm H(2)O when 5 cm H(2)O PEEP was removed. Six patients showed a clinically useful (> 20%) increase in PaO(2) with 5 cm H(2)O PEEP, and nine patients had a greater than 20% decrease in PaO(2). The change in PaO(2) with the application of 5 cm H(2)O PEEP correlated in an inverse fashion with the change in the gradient between the end-expiratory pressure and the pressure at the lower inflection point (r = 0.76). The subgroup of patients with a PaO(2) during two-lung ventilation that was less than the mean (365 mmHg) and an end-expiratory pressure during one-lung ventilation without applied PEEP less than the mean were more likely to have an increase in PaO(2) when 5 cm H(2)O PEEP was applied. CONCLUSIONS: The effects of the application of external 5 cm H(2)O PEEP on oxygenation during one-lung ventilation correspond to individual changes in the relation between the plateau end-expiratory pressure and the inflection point of the static compliance curve. When the application of PEEP causes the end-expiratory pressure to increase from a low level toward the inflection point, oxygenation is likely to improve. Conversely, if the addition of PEEP causes an increased inflation of the ventilated lung that raises the equilibrium end-expiratory pressure beyond the inflection point, oxygenation is likely to deteriorate.
P D Slinger; M Kruger; K McRae; T Winton
Related Documents :
15673897 - Positive end-expiratory pressure during induction of general anesthesia increases durat...
16879727 - Measurement of peep-induced alveolar recruitment: just a research tool?
6323367 - Effect of ventilation and perfusion imbalance on inert gas rebreathing variables.
359057 - Positive end expiratory pressure: effects on lung mechanics of premature lambs.
3084237 - The influence of hyperventilation on the measurement of stroke volume using a co2 rebre...
4091047 - Both high and low blood pressures risk indicators of death in middle-aged males. isoton...
Publication Detail:
Type:  Clinical Trial; Journal Article    
Journal Detail:
Title:  Anesthesiology     Volume:  95     ISSN:  0003-3022     ISO Abbreviation:  Anesthesiology     Publication Date:  2001 Nov 
Date Detail:
Created Date:  2001-10-30     Completed Date:  2001-12-07     Revised Date:  2004-11-17    
Medline Journal Info:
Nlm Unique ID:  1300217     Medline TA:  Anesthesiology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1096-102     Citation Subset:  AIM; IM    
Department of Anesthesia, University Health Network, University of Toronto, Toronto General Hospital, Ontario, Candada.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Forced Expiratory Volume
Intraoperative Care / methods
Lung Compliance*
Maximal Expiratory Flow Rate
Middle Aged
Positive-Pressure Respiration*
Thoracic Diseases / surgery*
Comment In:
Anesthesiology. 2002 Aug;97(2):523-4; author reply 524   [PMID:  12151952 ]

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

Previous Document:  Shiver suppression using focal hand warming in unanesthetized normal subjects.
Next Document:  Activation of coagulation and fibrinolysis during coronary surgery: on-pump versus off-pump techniqu...