Dynamic elastic pressure-volume loops in healthy pigs recorded with inspiratory and expiratory sinusoidal flow modulationRelationship to static pressure-volume loops.
(2004) In Intensive Care Medicine 30(3). p.481-488- Abstract
- Objective: The objective was to analyse relationships between inspiratory and expiratory static and dynamic elastic pressure-volume (P-el/V) curves in healthy pigs. Design: The modulated low flow method was developed to allow studies also of the expiratory P-el/V curves. Static P-el/V (P-el,P-st/V) and dynamic P-el/V (P-el,P-dyn/V) loops were studied in healthy pigs. Setting: Animal research laboratory in a university hospital. Material: Ten healthy anaesthetised and paralysed pigs. Interventions and measurements: A computer controlled a Servo Ventilator 900C with respect to respiratory rate, inspiratory flow and expiratory pressure to achieve a sinusoidal modulation of inspiration and expiration for determination of P-el,P-dyn/V loops... (More)
- Objective: The objective was to analyse relationships between inspiratory and expiratory static and dynamic elastic pressure-volume (P-el/V) curves in healthy pigs. Design: The modulated low flow method was developed to allow studies also of the expiratory P-el/V curves. Static P-el/V (P-el,P-st/V) and dynamic P-el/V (P-el,P-dyn/V) loops were studied in healthy pigs. Setting: Animal research laboratory in a university hospital. Material: Ten healthy anaesthetised and paralysed pigs. Interventions and measurements: A computer controlled a Servo Ventilator 900C with respect to respiratory rate, inspiratory flow and expiratory pressure to achieve a sinusoidal modulation of inspiration and expiration for determination of P-el,P-dyn/V loops from zero end-expiratory pressure (ZEEP) and from a positive end-expiratory pressure (PEEP) of 6 cmH(2)O to 20, 35 and 50 cmH(2)O. The same system was used for studies of P-el,P-st/V loops with the flow-interruption method from ZEEP and PEEP to 35 cmH(2)O. Recordings were analysed with an iterative technique. Results: The feasibility of automated determination of P-el,P-dyn/V loops was demonstrated. Differences between P-el,P-dyn/V and P-el,P-st/V loops were explained by viscoelastic behaviour. P-el,P-st/V loops recorded from PEEP to 35 cmH(2)O showed no significant hysteresis, indicating a non-significant surface tension hysteresis. P-el,P-dyn/V loops from PEEP and both P-el,P-st/V and P-el,P-dyn/V loops from ZEEP to 35 cmH(2)O showed hysteresis. This indicates that lung collapse/re-expansion caused P-el/V loop hysteresis which, in P-el,P-dyn/V loops, was augmented by viscoelastic behaviour. Conclusions: Viscoelasticity influences P-el,P-dyn/V curves. Hysteresis caused by surface tension merits re-evaluation. Lung collapse and re-expansion may be indicated by hysteresis of P-el/V loops. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/120534
- author
- Bitzén, Ulrika LU ; Drefeldt, Björn LU ; Niklason, Lisbet LU and Jonson, Björn LU
- organization
- publishing date
- 2004
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- mechanical, respiratory mechanics, hysteresis, compliance, ventilation, swine
- in
- Intensive Care Medicine
- volume
- 30
- issue
- 3
- pages
- 481 - 488
- publisher
- Springer
- external identifiers
-
- wos:000189364300021
- pmid:14963643
- scopus:1642329179
- ISSN
- 0342-4642
- DOI
- 10.1007/s00134-003-2156-6
- language
- English
- LU publication?
- yes
- id
- 8b34dd04-e16a-422e-926c-b23a14a4247a (old id 120534)
- alternative location
- http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=14963643&dopt=Abstract
- date added to LUP
- 2016-04-01 11:45:27
- date last changed
- 2022-04-05 04:39:07
@article{8b34dd04-e16a-422e-926c-b23a14a4247a,
abstract = {{Objective: The objective was to analyse relationships between inspiratory and expiratory static and dynamic elastic pressure-volume (P-el/V) curves in healthy pigs. Design: The modulated low flow method was developed to allow studies also of the expiratory P-el/V curves. Static P-el/V (P-el,P-st/V) and dynamic P-el/V (P-el,P-dyn/V) loops were studied in healthy pigs. Setting: Animal research laboratory in a university hospital. Material: Ten healthy anaesthetised and paralysed pigs. Interventions and measurements: A computer controlled a Servo Ventilator 900C with respect to respiratory rate, inspiratory flow and expiratory pressure to achieve a sinusoidal modulation of inspiration and expiration for determination of P-el,P-dyn/V loops from zero end-expiratory pressure (ZEEP) and from a positive end-expiratory pressure (PEEP) of 6 cmH(2)O to 20, 35 and 50 cmH(2)O. The same system was used for studies of P-el,P-st/V loops with the flow-interruption method from ZEEP and PEEP to 35 cmH(2)O. Recordings were analysed with an iterative technique. Results: The feasibility of automated determination of P-el,P-dyn/V loops was demonstrated. Differences between P-el,P-dyn/V and P-el,P-st/V loops were explained by viscoelastic behaviour. P-el,P-st/V loops recorded from PEEP to 35 cmH(2)O showed no significant hysteresis, indicating a non-significant surface tension hysteresis. P-el,P-dyn/V loops from PEEP and both P-el,P-st/V and P-el,P-dyn/V loops from ZEEP to 35 cmH(2)O showed hysteresis. This indicates that lung collapse/re-expansion caused P-el/V loop hysteresis which, in P-el,P-dyn/V loops, was augmented by viscoelastic behaviour. Conclusions: Viscoelasticity influences P-el,P-dyn/V curves. Hysteresis caused by surface tension merits re-evaluation. Lung collapse and re-expansion may be indicated by hysteresis of P-el/V loops.}},
author = {{Bitzén, Ulrika and Drefeldt, Björn and Niklason, Lisbet and Jonson, Björn}},
issn = {{0342-4642}},
keywords = {{mechanical; respiratory mechanics; hysteresis; compliance; ventilation; swine}},
language = {{eng}},
number = {{3}},
pages = {{481--488}},
publisher = {{Springer}},
series = {{Intensive Care Medicine}},
title = {{Dynamic elastic pressure-volume loops in healthy pigs recorded with inspiratory and expiratory sinusoidal flow modulationRelationship to static pressure-volume loops.}},
url = {{http://dx.doi.org/10.1007/s00134-003-2156-6}},
doi = {{10.1007/s00134-003-2156-6}},
volume = {{30}},
year = {{2004}},
}