Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Apr 1994
Soluble fibrin and D-dimer as detectors of hypercoagulability in patients with isolated brain trauma.
To test the hypothesis that hypercoagulability after brain trauma was related to the severity of injury and also to outcome, new coagulation markers were used in 20 patients with isolated brain trauma. In addition to routine coagulation tests, soluble fibrin (SF), D-dimer, and antithrombin (AT) levels were assessed. Thirteen of 20 patients had a Glasgow coma score (GCS) of < or = 7 on admission and severe disability (SD) or worse on the Glasgow outcome scale (GOS). ⋯ Six of 13 patients with a significant drop in AT levels had a bad outcome (D or V) whereas only two of seven patients without AT consumption did poorly. Routine coagulation studies were often pathologic, i.e., reduced platelet count, but there was no relation to outcome. Increased SF and D-dimer levels at admission followed by a secondary decrease in AT concentration and platelets seem to be good markers of the posttraumatic hypercoagulation often seen after brain injury.(ABSTRACT TRUNCATED AT 250 WORDS)
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J Neurosurg Anesthesiol · Apr 1994
Sitting position for neurosurgery: experience with preoperative contrast echocardiography in 301 patients.
A persisting foramen ovale (PFO) is the most common cause of paradoxical air embolism. To detect right-to-left shunting, transthoracic contrast echocardiography was performed preoperatively in 301 patients scheduled for neurosurgical procedures in the sitting position. Echocardiography yielded evaluable results in 285 patients (94.7%). ⋯ If echo signals appeared in the left heart after more than 5 heart cycles, an intrapulmonary right-to-left shunt was considered (11 patients, 3.9%). Venous air embolism (VAE) occurred in 27.4% of 226 patients operated on in the sitting position and in none of the 59 patients operated on in a nonsitting position. We conclude that the sitting position during neurosurgery should be avoided in patients with preoperative evidence of a right-to-left shunt at contrast echocardiography to reduce the risk of paradoxical air embolism (PAE).
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Hydroxocobalamin is a powerful cyanide antidote that prevents sodium nitroprusside-induced cyanide toxicity. The pharmacokinetics of an i.v. bolus of hydroxocobalamin (70 and 140 mg/kg) were studied in conscious dogs (n = 6). Plasma hydroxocobalamin concentrations were measured using derivative spectrophotometry. ⋯ At 70 mg/kg, which is the recommended dose in acute cyanide poisoning, the elimination half-life was 7.36 +/- 0.79 h, the volume of distribution was 0.49 +/- 0.10 L/kg, and the total clearance 0.58 +/- 0.11 L/h. At high doses, hydroxocobalamin has a short elimination half-life and a limited volume of distribution that exceeds blood volume. These results could be useful in elaborating guidelines for the administration of hydroxocobalamin, when repetitive bolus and/or continuous infusion is required.
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J Neurosurg Anesthesiol · Jan 1994
Incidence and clinical significance of hemidiaphragmatic paresis in patients undergoing carotid endarterectomy during cervical plexus block anesthesia.
This study was designed to investigate the incidence and clinical consequences of hemidiaphragmatic paresis in patients undergoing carotid endarterectomy using cervical plexus block anesthesia. In 28 patients, diaphragmatic motion was evaluated by fluoroscopy 20 min after cervical plexus block with 1% mepivacaine. ⋯ These motion anomalies were associated with a statistically significant elevation of PaCO2. Gender, age, and whether the block was on the left or right side did not appear to affect the incidence of motion abnormalities after cervical plexus block anesthesia.
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J Neurosurg Anesthesiol · Jan 1994
Case ReportsVenous air embolism after craniotomy closure: tension pneumocephalus implicated.
The authors present a case of venous air embolism occurring immediately upon skin closure after craniotomy in the prone position. This 5-year-old patient had a third ventricle tumor resected with bipolar cautery via a frontal trans-collosal approach into the lateral ventricle and through the foramen of Monroe. Doppler monitoring was utilized during the case since the patient's head was extended upwards in 10 degrees reverse Trendelenburg position. ⋯ The ventricles were filled with saline presumably displacing air, prior to dural closure. However, with an increase in nitrous oxide from 55 to 68% prior to skin closure, venous air embolism was subsequently detected by Doppler and confirmed by end-tidal/arterial pCO2 gradient. The authors speculate that tension pneumocephalus caused the venous air embolism and describe the probable route of entry into the venous system.