Document Detail


Local vascular response during organ elevation. A model for cerebral effects of upright position and dural puncture.
MedLine Citation:
PMID:  10225078     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: Dural puncture can be followed by postural headache and, in patients with cerebral infections, by brain stem herniation. The present study evaluates whether these complications may be related to the changes in hydrostatic pressure generated by the spinal fluid column when the dural sac surrounding the cerebrospinal tissue has been punctured. METHOD: An isolated cat skeletal muscle enclosed in a plethysmograph connected to a tube served as a model imitating the brain, the cranium and the spinal canal. We investigated effects of organ elevation on tissue pressure, venous collapse (venous outflow resistance) and tissue volume with closed "spinal" tube (intact dural sac) and open "spinal" tube (dural puncture), and effects of compliance of the draining veins. RESULTS: Organ elevation with closed "spinal" tube induced a decreased tissue pressure, whereas tissue pressure remained unchanged if arterial inflow pressure to the muscle was kept constant. Organ elevation with the "spinal" tube opened distally caused a significantly larger decrease in tissue pressure, venous dilation and disappearance of venous outflow resistance. Transcapillary filtration increased, and the filtration rate was higher with high than with low venous compliance. CONCLUSION: If our results are applicable to the brain, changing to an upright position following a lumbar dural puncture may generate a negative hydrostatic force and a negative interstitial cerebral pressure, causing an increased transvascular pressure and dilation of the cerebral outflow veins. The corresponding increase in cerebral blood volume may induce post-spinal headache, and the increased transcapillary pressure may cause increased fluid filtration and brain oedema if the blood-brain barrier is disrupted.
Authors:
L Kongstad; P O Grände
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Acta anaesthesiologica Scandinavica     Volume:  43     ISSN:  0001-5172     ISO Abbreviation:  Acta Anaesthesiol Scand     Publication Date:  1999 Apr 
Date Detail:
Created Date:  1999-06-18     Completed Date:  1999-06-18     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370270     Medline TA:  Acta Anaesthesiol Scand     Country:  DENMARK    
Other Details:
Languages:  eng     Pagination:  438-46     Citation Subset:  IM    
Affiliation:
Department of Physiology, University of Lund, Sweden.
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MeSH Terms
Descriptor/Qualifier:
Animals
Blood Pressure / physiology
Blood Volume
Blood-Brain Barrier / physiology
Brain / blood supply*,  physiology
Brain Diseases / microbiology
Brain Edema / etiology
Brain Stem / pathology
Capillaries / physiology
Cats
Cerebral Veins / physiology
Cerebrospinal Fluid Pressure / physiology
Cerebrovascular Circulation / physiology
Disease Models, Animal
Dura Mater / physiology
Encephalocele / etiology
Headache / etiology
Hydrostatic Pressure
Muscle, Skeletal / blood supply
Plethysmography / instrumentation
Posture / physiology*
Spinal Puncture* / adverse effects
Vascular Resistance / physiology
Vasodilation / physiology
Veins / physiology

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


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