Lipid resuscitation: a life-saving antidote for local anesthetic toxicity.

Local anesthetic toxicity is a rare, but potentially lethal, complication of regional anesthesia that cannot be prevented by any single measure. It is associated with CNS excitation and can lead to refractory cardiac dysfunction and collapse. The development of lipid emulsion for the treatment of anesthetic-induced toxicity resulted from a set of observations during a study on the potent, lipophilic drug bupivacaine and its associated clinical risk of intransigent cardiac toxicity in otherwise healthy individuals. Subsequent laboratory studies and clinical reports have shown that infusion of lipid can reliably reverse toxicity from potent local anesthetics as well as other drugs. The underlying mechanisms of lipid resuscitation may be a combination of a 'lipid sink' and metabolic effect. Lipid rescue has led to a reduction in fatalities associated with severe systemic toxicity, but continued research is necessary for a better mechanistic understanding. Increased physician awareness and education, as well as optimized treatment protocols, will significantly reduce the rate of morbidity and mortality from local anesthetic toxicity.

Pedal manifestations of Milroy's disease.

A pedal complication of Milroy's disease has been presented. With a history of multiple debridement procedures as in this case, there is the risk of recurrent infections and the possibility of permanent vascular compromise, particularly with respect to the thin pedal skin on the dorsal aspect. When the toes are recurrently involved with infection, a patient may be best served with a transmetatarsal amputation using a skin flap on the plantar aspect.

The effect of dextran on microvascular thrombosis in an experimental rabbit model.

Although low molecular weight dextran is commonly utilized in clinical microsurgery, few experimental data are available documenting its efficacy. Bilateral 2-mm arterial inversion grafts were constructed in the femoral arteries of New Zealand White rabbits. The experimental group (n = 40 grafts) received a 5-day constant infusion of intravenous dextran 40 at 2.1 ml/hour, and the control group (n = 50 grafts) received no infusion. Whereas 85 percent (34/40) of the dextran grafts were patent at 1 week, only 48 percent (24/50) of the control grafts were patent (p = 0.0003). Scanning electron micrographs revealed a decrease in both platelet and fibrin deposition in the patent dextran arterial inversion grafts versus the patent control specimens. As a marked diminution in microvascular thrombosis was demonstrated at a clinically relevant dose, the continued use of intravenous dextran 40 in clinical microsurgery is supported by this study.

The biophysical and histologic properties of capsules formed by smooth and textured silicone implants in the rabbit.

Capsular contracture remains the major complication of reconstructive and aesthetic breast surgery. The purpose of this investigation was to determine if a silicone implant with a textured surface will form a capsule of significantly different biophysical and histologic properties than conventional smooth silicone. Thirty smooth and 30 textured silicone tissue expanders were implanted under the panniculus carnosus of rabbits. After 3 months, measurements related to contracture were performed on anesthetized animals in an investigator-blinded, controlled manner. Intraexpander pressures were measured as saline was injected over time. We found a significant correlation between intraexpander pressures, applanation tonometry, and Baker class. Histology revealed a thicker, more adherent, and inflammatory capsule around the textured silicone implants as compared with the smooth silicone implants. Dynamic pressures were plotted against volume of saline within the two types of implants. Statistical analysis revealed that the textured implants form a tighter and thicker capsule than the smooth implants after 3 months of observation (p less than 0.005).

Airflow through the eustachian tube.

In an attempt to distinguish normal from abnormal eustachian tube function, two groups of adults with nonintact tympanic membranes were tested. Six subjects had traumatic perforations of the tympanic membrane and a negative otologic histroy while five subjects had perforations as a sequela of otitis media. The subjects were tested with two methods: the middle ear inflation-deflation technique and a newly introduced forced-response technique. The comparison of the two groups revealed marked differences between normal subjects and patients with middle ear disease in active tubal dilation mechanisms and biomechanics of the eustachian tube. The forced-response test appeared to be a better method to determine the degree of actual tubal function.

Comparison between lergotrile and bromocriptine in parkinsonism.

The therapeutic and adverse effects of two ergot derivatives, bromocriptine and lergotrile, were compared in idiopathic parkinsonism. At both low (50 mg daily) and high (150 mg daily) dosage there was a similar but not identical profile of response. Initially, lergotrile tended to induce more severe but always transient hypotension. At higher doses, bromocriptine caused more dyskinesia. Neurological deficits improved with increasing doses up to an average daily level of 80 to 150 mg of ergot derivatives combined with levodopa, 450 to 1,150 mg, and carbidopa, 45 to 115 mg. However, efficacy often declined at the highest doses of antiparkinsonian agents. Adverse effects caused by ergot derivatives are more common with dosages greater than 100 mg per day. In general, the best overall therapeutic results with bromocriptine and lergotrile were obtained in the dose range of 50 to 100 mg daily for each. It is concluded that bromocriptine and lergotrile are similar in their therapeutic properties and that both are comparable in efficacy to levodopa plus carbidopa (though optimal results are commonly obtained by combining submaximal doses of levodopa with ergot derivatives). The role for each drug in the treatment of parkinsonism is likely to be determined by factors such as cost (bromocriptine) and hepatotoxicity (lergotrile).

Experiences with a new ergoline (CF 25-397) in parkinsonism.

Studies on rats with unilateral nigral lesions suggest that a new ergoline, CF 25-397, is a dopaminergic agonist that might improve parkinsonism. CF 25-397 induces less stereotyped behavior than other dopaminergic agents in rats, and might therefore cause less dyskinesia than levodopa in man. We investigated the clinical actions of CF 25-397 in nine patients. During treatment, severe deterioration resulted in hypokinesia and rigidity; five patients showed marked dysphagia and dysphonia. There was statistically significant deterioration in four timed tests. Mild improvement, not statistically significant, was noted in tremor. These results indicate that clinical implication of the response to potential therapeutic agents in rodent models of parkinsonism must be interpreted with caution.