McConnell's sign in intra-operative acute right ventricle ischaemia: An under-recognized aetiology. / Signo de McConnell en isquemia aguda de ventrículo derecho intraoperatoria: una etiología poco reconocida.

Transoesophageal echocardiography (TEE) has become a fundamental tool in modern cardiothoracic anaesthesia. It has an indisputable role in coronary valve surgery and revascularisations with severe impairment of ventricle function. It helps in making diagnoses that can optimise the surgical strategy and to minimal invasively dynamically monitor volaemia and cardiac function during the post-operative period, detecting complications unobservable by other methods. The McConnell sign, visualised using TEE as an akinesis of the right ventricular free wall, with a normal apex motility and enlargement of the right cavities, is characteristic of right ventricular (RV) dysfunction. This sign has a 77% sensitivity and 94% specificity for the diagnosis of acute pulmonary embolism (APE). The case is presented of a 53-year-old man scheduled for aortic valve and ascending aorta replacement surgery, with a history of severe valve aortic stenosis, aortic root and arch aneurysm, and with normal coronary arteries. Post-cardiopulmonary bypass (CBP), the patient presented with haemodynamic instability, with the TEE showing a typical image of the McConnell sign, with no pulmonary hypertension. This enabled making an early diagnosis of acute RV ischaemia, that led to a change in the surgical plan, the performing of coronary revascularisation surgery. As a result, the McConnell sign, which describes the characteristics of RV dysfunction, led to making a differential diagnosis between APE, RV infarction and acute myocardial ischaemia.

Meconium has no lecithin or sphingomyelin but affects the lecithin/sphingomyelin ratio.

OBJECTIVE: Although a few studies have evaluated the effect of meconium on the lecithin/sphingomyelin ratio for testing of fetal lung maturity, to date these studies have assessed only the lecithin-sphingomyelin ratio of amniotic fluid contaminated with meconium. The purpose of this study was (1) to determine whether meconium by itself has a lecithin/sphingomyelin ratio and, if so, (2) to determine whether the lecithin/sphingomyelin ratio is constant. STUDY DESIGN: A lecithin/sphingomyelin ratio was obtained by standard thin-layer chromatography on the first meconium stool of 20 neonates between 31 weeks and term. A quantitative assay was then performed on a sample from each gestational age (7 samples ranging from 31 weeks to term) to confirm the presence of lecithin and sphingomyelin. RESULTS: The 20 samples had atypical thin-layer chromatographic migratory patterns in the zones for lecithin and sphingomyelin. The presumed lecithin/sphingomyelin ratios ranged from 1.1 to 3.6, with no correlation with gestational age. However, the quantitative assay did not detect the presence of lecithin or sphingomyelin in any of the analyzed samples. CONCLUSIONS: Meconium does not appear to contain lecithin or sphingomyelin but has an unidentified moiety whose migratory pattern, as shown by qualitative standard thin-layer chromatography, is similar to that of lecithin with sphingomyelin. Therefore the presence of meconium in amniotic fluid may falsely raise or lower the lecithin/sphingomyelin ratio and confuse fetal lung maturity interpretations.