OBJECTIVE: To compare the respective effects of established measures used for management of traumatic brain injury (TBI) patients on cerebral blood flow (CBF) and cerebral metabolic rates of oxygen (CMRO2), glucose (CMRGlc) and lactate (CMRLct). METHODS: Thirty-six patients suffering from severe traumatic brain injury (TBI) were prospectively evaluated. In all patients baseline assessments were compared with that following moderate hyperventilation (reducing PaCO2 from 36 +/- 4 to 32 +/- 4 mmHg) and with that produced by administration of 0.5 gr/kg mannitol 20% intravenously. Intracranial and cerebral perfusion pressure (ICP, CPP), CBF and arterial jugular differences in oxygen, glucose and lactate contents were measured for calculation of CMRO2, CMRGlc and CMRLct. RESULTS: Following hyperventilation, CBF was significantly reduced (P < 0.0001). CBF remained most often above the ischemic range although values less than 30 ml x 100 gr(-1) x min(-1) were found in 27.8% of patients. CBF reduction was associated with concurrent decrease in CMRO2, anaerobic hyperglycolysis and subsequent lactate production. In contrast, mannitol resulted in significant albeit moderate improvement of cerebral perfusion. However, administration of mannitol had no ostensible effect either on oxidative or glucose metabolism and lactate balance remained mostly unaffected. CONCLUSIONS: Moderate hyperventilation may exacerbate pre-existing impairment of cerebral blood flow and metabolism in TBI patients and should be therefore carefully used under appropriate monitoring. Our findings rather support the use of mannitol for ICP control.
OBJECTIVE: To compare the respective effects of established measures used for management of traumatic brain injury (TBI) patients on cerebral blood flow (CBF) and cerebral metabolic rates of oxygen (CMRO2), glucose (CMRGlc) and lactate (CMRLct). METHODS: Thirty-six patients suffering from severe traumatic brain injury (TBI) were prospectively evaluated. In all patients baseline assessments were compared with that following moderate hyperventilation (reducing PaCO2 from 36 +/- 4 to 32 +/- 4 mmHg) and with that produced by administration of 0.5 gr/kg mannitol 20% intravenously. Intracranial and cerebral perfusion pressure (ICP, CPP), CBF and arterial jugular differences in oxygen, glucose and lactate contents were measured for calculation of CMRO2, CMRGlc and CMRLct. RESULTS: Following hyperventilation, CBF was significantly reduced (P < 0.0001). CBF remained most often above the ischemic range although values less than 30 ml x 100 gr(-1) x min(-1) were found in 27.8% of patients. CBF reduction was associated with concurrent decrease in CMRO2, anaerobic hyperglycolysis and subsequent lactate production. In contrast, mannitol resulted in significant albeit moderate improvement of cerebral perfusion. However, administration of mannitol had no ostensible effect either on oxidative or glucose metabolism and lactate balance remained mostly unaffected. CONCLUSIONS: Moderate hyperventilation may exacerbate pre-existing impairment of cerebral blood flow and metabolism in TBIpatients and should be therefore carefully used under appropriate monitoring. Our findings rather support the use of mannitol for ICP control.
Authors: Mauro Oddo; Daniele Poole; Raimund Helbok; Geert Meyfroidt; Nino Stocchetti; Pierre Bouzat; Maurizio Cecconi; Thomas Geeraerts; Ignacio Martin-Loeches; Hervé Quintard; Fabio Silvio Taccone; Romergryko G Geocadin; Claude Hemphill; Carole Ichai; David Menon; Jean-François Payen; Anders Perner; Martin Smith; José Suarez; Walter Videtta; Elisa R Zanier; Giuseppe Citerio Journal: Intensive Care Med Date: 2018-03-02 Impact factor: 17.440
Authors: Angela N Hays; Christos Lazaridis; Ron Neyens; Joyce Nicholas; Sarah Gay; Julio A Chalela Journal: Neurocrit Care Date: 2011-04 Impact factor: 3.210