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Biomedical subjects

M Cormio

Publications and source records attributed to M Cormio.

22 records · Page 2Linked to original sources

Lactate and excitatory amino acids measured by microdialysis are decreased by pentobarbital coma in head-injured patients.

Primary traumatic brain injury and secondary ischemic/hypoxic injury are being increasingly characterized at the neurochemical level. Neurochemical monitoring using microdialysis has shown that these forms of tissue damage share many common features. In particular, anaerobic glycolysis with increased lactate production and release of excitatory amino acids into the extracellular space are seen in both conditions. Clinical microdialysis studies have heretofore focused on methodological issues, establishment of basal analyte values, and clinico-neurochemical correlation. Here we report the neurochemical consequences of therapeutic intervention in head injury. Specifically, induction of thiopental coma to manage severe increased intracranial pressure in seven patients was associated with a 37% reduction of lactate, 59% reduction of glutamate, and 66% reduction in aspartate in the extracellular space of the brain.

Adolescent↗

Intraoperative jugular desaturation during surgery for traumatic intracranial hematomas.

Traumatic intracranial hematomas which are present on hospital admission or which develop during the hospital course are associated with a worse neurological outcome than diffuse injuries. The purpose of this study was to monitor jugular venous oxygen saturation (Sjvo2) during surgery for evacuation of traumatic intracranial mass lesions, to determine the incidence and the causes of jugular venous desaturation, and to assess the usefulness of Sjvo2 monitoring in this setting. Twenty-five severely head injured patients were monitored during 27 surgical procedures. At the start of the surgical procedure, the median Sjvo2 was 47% (range 25%-89%). Seventeen (63%) of the patients had a Sjvo2 less than 50%. Five patients had extremely low Sjvo2 values (< or = 30%). Upon evacuation of the intracranial hematoma, there was a significant (P < 0.001) increase in the median Sjvo2 to 65% (range 50%-88%). Intracranial hypertension was the primary cause of the low Sjvo2, as confirmed by the response to surgical evacuation. Hypotension (mean arterial pressure < 80 mm Hg) was a contributing factor in seven of the cases of jugular desaturation. The definitive treatment of a traumatic intracranial hematoma is surgical evacuation. However, during the period prior to evacuation of the hematoma, jugular venous desaturation was common, suggesting that monitoring Sjvo2 might provide useful information about the adequacy of cerebral perfusion.

Adult↗

Cerebral metabolic management.

Knowledge of cerebral metabolic variables increases the information available for managing the head-injured patient. This article reviews normal cerebral metabolism and describes the derangement of metabolism observed in patients with head trauma. Cerebral metabolism is globally decreased by one third to one half in the severely head-injured patient, usually because of the lower metabolic expenditure associated with coma, but sometimes because of superimposed hypoxia/ischemia, primarily due to secondary insults. Measurement of jugular venous oxygen saturation has become the most useful method for monitoring cerebral metabolism in the ICU. Although jugular venous oxygen saturation does not provide quantitative information about either cerebral blood flow or cerebral metabolism, it reflects the ratio between these two variables. To maintain a sufficient level of available oxygen and energy production at the cellular level, there are two therapeutic strategies: a) hemodynamic and b) metabolic. Treatments can be directed at both increasing oxygen delivery and integrating hemodynamic handling, and at various pharmacologic or physical methods intended to reduce the cerebral metabolic demand. The latter strategy is designed to depress either the basal or activation components of cerebral metabolism. This strategy includes manipulations of brain temperature and the use of central nervous system-depressant, barbiturate, and similar drugs.

Blood Gas Analysis↗