Fatal diffuse thrombotic microangiopathy after a bite by the "Fer-de-Lance" pit viper (Bothrops lanceolatus) of Martinique.

In Martinique, a man bitten two days earlier by a pit viper (Bothrops lanceolatus) was hospitalized with impaired consciousness and tetraplegia. Investigations confirmed cerebral and myocardial infarctions. Resolving thrombocytopenia was associated with virtually normal blood prothrombin time/activated partial thromboplastin time but increasing hyperfibrinogenemia. Despite specific antivenom treatment, he developed fatal left ventricular failure six days after the bite. At autopsy, multiple cerebral, myocardial and mesenteric infarctions were found. Rupture of mitral chordae tendinae was the likely cause of death. Histopathologic examination showed multi-focal thrombotic microangiopathy with intimal-medial dissection by thrombi extending from foci of endothelial damage in small cerebral, myocardial, pulmonary, mesenteric, and interlobular renal arteries and arterioles. These findings were the causes of infarctions. There was intense angiogenesis in organizing cerebral infarcts. Immunohistochemical analysis showed platelet aggregates and endothelial cells within microthrombi. Viperidae venoms contain vascular endothelial toxins, notably metalloproteinase hemorrhagins, but von Willebrand factor activators or vascular endothelial growth factor-type factors are more likely to have been implicated in this case.

[The coracoid block: demonstration of a simple approach using the pectoralis minor as landmark]. / Le bloc coracoïdien : mise en évidence d'une voie d'abord simple utilisant le petit pectoral.

OBJECTIVE: Despite their recognized advantages, infraclavicular blocks, especially with the pericoracoid approach, are underutilized because the lack of simple anatomical landmarks. The goal of this study is to determine a simple, reliable and reproducible reference point by means of magnetic resonance imaging (MRI), using the anterior extremity of the coracoid process, and the pectoralis minor as a tactile reference point. METHOD: Sagittal and para-sagittal MRI sections at the coracoid process were performed on 11 patients. The relationships between the coracoid process, the nerve-vessel bundle, the pectoralis minor and the skin were measured. RESULTS: The optimal puncture point for a needle introduced strictly in an anterio-posterior direction in a supine, alert patient is located 2 cm within and 2.5 cm below the coracoid process. The injection point, defined as the distance between the skin and the tip of the needle lying in the centre of the visualized nerve-vessel bundle, is located an average of 5 cm from the skin (mean 5.02 cm, with a standard deviation of 1.03 and a confidence interval of 0.91). This injection point goes from 0.4 cm (at the most anterior part of the bundle) and 1.75 cm (at the most posterior part), with an average 1 cm from the posterior surface of the pectoralis minor (tactile reference point). Neither body mass index nor sex influence significantly the variables measured. CONCLUSIONS: The reference points defined here could allow easy and reproducible performance of this relatively simple block and make it more effective.