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Cerebral haemodynamic effects of dihydroergotamine in patients with severe traumatic brain lesions
Author(s) -
Asgeirsson B.,
Grande P. O.,
Nordström C. H.,
Messeter K.,
Sjöholm H.
Publication year - 1995
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1995.tb04199.x
Subject(s) - hyperventilation , medicine , dihydroergotamine , anesthesia , cerebral blood flow , vasoconstriction , hemodynamics , bolus (digestion) , constriction , traumatic brain injury , cardiology , migraine , psychiatry
Dihydroergotamine (DHE) is used in our recently introduced therapy of post‐traumatic brain oedema and is suggested to reduce ICP through reduction in both cerebral blood volume and brain water content. This study aims at increasing our knowledge of the mechanisms behind the ICP reducing effect of DHE by analysing cerebrovascular effects of a bolus dose of DHE in severely head injured patients (GCS<8). Mean hemispheric cerebral blood flow (CBF) calculated from the clearance of i.v. 133 Xenon, ICP, and cerebral arterio‐venous difference in oxygen content (AVDO 2 ), were measured before and after hyperventilation and after a bolus dose of DHE (4 μg/kg). The patients were divided into two groups, one with preserved and one with impaired cerebrovascular CO 2 ‐reactivity to hyperventilation, the latter being predictive of poor outcome. The haemodynamic effects of DHE were compared to those of hyperventilation. Regional CBF and brain volume SPECT measurements were performed in two patients. DHE increased cerebrovascular resistance (CVR) by about 20% and significantly reduced ICP in both groups of patients, resulting in unchanged AVDO 2 . Hyperventilation with preserved CO 2 ‐reactivity caused a similar decrease in ICP as by DHE but with a much larger increase in CVR (by 70%) and a substantial increase in AVDO 2 . Hyperventilation with impaired CO 2 ‐reactivity reduced ICP but otherwise had no significant cerebrovascular effects. The study supports the concept that the ICP reducing effect of DHE results more from constriction of the large veins than from arterial vasoconstriction, also implying a relatively smaller risk of ischaemia with DHE than with hyperventilation.