Transient radicular pain following spinal anesthesia: review of the literature and report of a case involving 2% lidocaine.

Recent reports of transient radicular irritation following intrathecal administration of 5% lidocaine in 7.5% dextrose, a common drug choice in many obstetric centers, have generated concern that its use for single injection spinal anesthesia can result in transient neurologic toxicity. Accordingly, many have advocated dilution of this anesthetic solution prior to subarachnoid administration. The present report describes a case in which transient neurologic symptoms occurred following intrathecal injection of a solution containing approximately 2% lidocaine. The similarity of the present case to those previously reported implies a common etiology and suggests that risk is not restricted to the use of 5% lidocaine with 7.5% glucose. It underscores the need for carefully controlled prospective evaluation of the factors that affect transient neurologic dysfunction following spinal anesthesia.

Costs and benefits of prenatal screening for cystic fibrosis.

New tests promise to facilitate the prenatal detection of cystic fibrosis (CF), a fatal genetic disorder. This study examines the costs and benefits of prenatal screening and selective abortion using two types of tests: those based on restriction fragment-length polymorphisms (RFLPs), which can only be applied when genetic material is available from a CF-affected family member; and those based on probes for the newly discovered CF gene, which can be applied in the general population. When either type is applied in families of CF-affected children, even an expensive test produces substantial net benefits. Existing direct gene probe tests are not sensitive, although eventually they may become less expensive and more accurate than tests based on RFLPs. Even if these tests become highly accurate, the financial benefits of population-wide screening for CF are likely to be small or negative, particularly if testing does not lead to increases in the number of normal children as it decreases the number of births of CF-affected children. Because few children born in families without a history of CF have the disease, tests that are not perfectly specific will produce a large number of false-positive results, leading to the abortion of many normal fetuses.

Precipitated diazepam withdrawal elevates noradrenergic metabolism in primate brain.

Following treatment for seven days with diazepam (2.0 mg/kg i.m., b.i.d.), administration of the benzodiazepine receptor antagonist RO 15-1788 (5 mg/kg) induced a severe withdrawal syndrome in vervet monkeys which included tremors, vomiting, vocalizations, chewing, and piloerection. Brain concentrations of the noradrenergic metabolite 3-methoxy-4-hydroxyphenylglycol (MHPG) were significantly higher in the precipitated withdrawal group than in the diazepam plus vehicle control group. Administration of RO 15-1788 without prior diazepam treatment had no effect on brain MHPG, nor did it produce withdrawal behaviors, but did produce an increase in the frequency of scratching. These results raise the possibility that increased central noradrenergic activity serves a role in benzodiazepine withdrawal similar to the role hypothesized for noradrenergic activity in opiate withdrawal.