Limitations of computed tomographic angiography in the diagnosis of brain death.

OBJECTIVE: To evaluate the accuracy of cerebral computed tomographic angiography (CT-a) for the diagnosis of brain death (BD). DESIGN AND SETTING: Prospective observational study in intensive care units. PATIENTS: Twenty-one clinically BD patients enrolled over 12 months. MEASUREMENTS AND RESULTS: All clinically BD patients were evaluated by electroencephalography (EEG) and CT-a after exclusion of hypothermia and drug intoxication. Data collected included: demographic characteristics, cause of BD, delay between in-hospital admission and BD diagnosis and between EEG and CT-a, occurrence of cardiac arrest, administration of vasoactive agents, results of EEG and CT-a. We evaluated the sensitivity of EEG and CT-a and their agreement. Groups were compared according to BD diagnosis by EEG and CT-a (E+C+), or only by EEG (E+C(-)). Statistical analysis were performed by Mann-Whitney test and Fisher's exact test. BD was confirmed by EEG in all cases (sensitivity 100%) whereas only 11 patients of 21 had no cerebral perfusion during CT-a (sensitivity 52.4%). No agreement was documented between EEG and CT-a for the diagnosis of BD (kappa = 0). Patients' characteristics did not differ between E+C+ and E+C(-) groups. In the E+C(-) group arterial opacification was observed in 100% of patients, but opacification of the internal cerebral veins was achieved in only 30%. CONCLUSIONS: In clinically BD patients with no electroencephalographic activity CT-a documents opacification of the intracerebral vessels in a significant percentage of the cases. Therefore CT-a cannot be recommended as a means of BD diagnosis.

Paravertebral block with ropivacaine 0.5% versus systemic analgesia for pain relief after thoracotomy.

PURPOSE: Paravertebral block in combination to intravenous analgesics could be an alternative to epidural analgesia for postoperative pain control after thoracotomy, but it has been scarcely evaluated so far. We thus assessed the efficacy of paravertebral block using a continuous infusion of ropivacaine in a multimodal analgesic approach. DESCRIPTION: Forty patients were randomized to receive ketoprofen, paracetamol, and patient-controlled-analgesia (PCA) with intravenous morphine (control group) or the same treatment with a continuous 48-hour infusion of ropivacaine 0.5% (0.1 mL/kg(-1)/h(-1)) in a thoracic paravertebral catheter (thoracic paravertebral block [TPVB] group). Visual analog scale (VAS) at rest and when coughing, morphine consumption, and side effects were recorded during the first 48 hours after surgery. Venous blood was sampled at 24 and 48 hours for ropivacaine plasma concentration measurements. EVALUATION: Mean VAS scores at rest and when coughing were significantly decreased in the TPBV group (p < 0.005). Despite a decrease in the morphine-titrated dose given in the postanesthesia care unit, cumulated morphine consumption was not significantly different between the two groups (51 +/- 29 mg and 57 +/- 24 mg in the TPVB and control groups, respectively). Side effects (nausea, vomiting, urinary retention) were less frequent in the TPBV group (30% vs 75%; p < 0.005). Plasma ropivacaine concentrations remained below the toxic threshold. CONCLUSIONS: Continuous paravertebral ropivacaine 0.5% infusion improves pain control after thoracic surgery using a multimodal analgesic approach.