Canadian journal of anaesthesia = Journal canadien d'anesthésie
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Randomized Controlled Trial Clinical Trial
Epidural test dose: lidocaine 100 mg, not chloroprocaine, is a symptomatic marker of i.v. injection in labouring parturients.
The authors studied the sensitivity (SN) and specificity (SP) of an epidural test dose containing either lidocaine 100 mg or 2-chloroprocaine 100 mg as symptomatic markers of intravascular injection in labouring parturients. In a prospective, double-blind and randomized fashion 48 unmedicated and labouring parturients were equally divided into three groups. After placement of a lumbar epidural catheter the normal saline group (NS) received 5 ml normal saline i.v., the lidocaine group (LD) received lidocaine 100 mg i.v., and the 2-chloroprocaine group (CH) received 2-chloroprocaine 100 mg i.v. ⋯ Only in the LD group, tinnitus+taste and dizziness+taste reached a SN of 100% with a SP of 81% and 69% respectively. While the -PV was 100% for both groups of symptoms, the +PV reached 42% for tinnitus+taste and 30% for dizziness+taste. We conclude that lidocaine 100 mg is a sensitive marker of intravascular injection in labouring parturients, and that tinnitus+taste is the most reliable indicator of intravenous injection.
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Cortical blood flow (CoBF) was measured continuously by the laser-Doppler method to evaluate the effect of hypercapnia on cortical blood flow during ten surgical procedures in ten young patients (mean +/- SD 9.3 +/- 6.4 yr) with Moyamoya disease. The CoBF was 42.8 +/- 13.4 (ml.100 g-1.min-1) during normocapnia (PaCO2 = 39.0 +/- 2.4 mmHg), and 38.7 +/- 14.4 during hypercapnia (PaCO2 = 47.1 +/- 2.5 mmHg). ⋯ He concluded that patients with Moyamoya disease have a precarious cerebral circulation and hypercapnia may be detrimental to the cortical circulation. This suggests that normocapnia is preferable to hypercapnia in patients with Moyamoya disease during anaesthesia.
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Pressure-passive perfusion beyond the upper limit of cerebral blood flow (CBF) autoregulation may be deleterious in patients with intracranial pathology. Therefore, monitoring of changes in CBF would be of clinical relevance in situations where clinical evaluation of adequate cerebral perfusion is impossible. Noninvasive monitoring of cerebral blood flow velocity using transcranial Doppler sonography (TCD) may reflect relative changes in CBF. ⋯ Mean arterial blood pressure was increased by 76%. Heart rate and ICP did not change. Changes in MAP were associated with increases in cortical CBF (78%), brainstem CBF (87%) and cerebellum CBF (64%).(ABSTRACT TRUNCATED AT 250 WORDS)