Percutaneous fluoroscopic removal of a knotted Swan–Ganz catheter in a patient with a persistent left‐sided superior vena cava

Knotting of intravascular catheters is an uncommon but a well‐recognized occurrence. The Swan–Ganz catheter (SGC) is the one that knots most commonly. A case of a knotted SGC is described in a patient with a persistent left‐sided superior vena cava, and we propose that the presence of a left‐sided superior vena cava is a risk factor for knot formation not previously reported. We review the published work on the risk factors for knot formation and on the techniques used to remove knotted SGC. We describe a technique using a gooseneck snare and Omni Flush catheter (Angiodynamics, Queensbury, NY, USA) to loosen and untie a knotted SGC.     

Effect of fluoxetine on intraocular pressure in the rabbit

The effects of fluoxetine, which is a selective inhibitor of serotonin reuptake (SSRI) have been studied on the intraocular pressure (IOP) in the rabbit. IOP was measured using a Perkins tonometer. Intravenous administration of fluoxetine (6.0 mg kg-1) significantly increased IOP by 7.2 +/- 1.3 mmHg (P < 0.001). Fluoxetine administration also reduced the amount of urine excreted during the 24 hr, and increased the urine concentration of 5-hydroxyindole acetic acid (5-HIAA). Topical preadministration of ketanserin prevented a rise in IOP, without there being any effects on the other parameters examined. These findings indicate that intravenous administration of fluoxetine is able to raise IOP, through increased plasma levels of serotonin, which is confirmed by elevated 5-HIAA urine excretion and reduction in diuresis. Ketanserin, a specific 5-HT2A antagonist, counteracts the IOP increase brought about by fluoxetine, thus emphasizing the role of serotonin in the regulation of IOP and stressing the importance of including ophthalmological examination in the protocol of depressed patients undergoing SSRI therapy.     

Cardiac abnormalities in end stage renal failure and anaemia

Thirteen anaemic children on dialysis were assessed to determine the incidence of cardiac changes in end stage renal failure. Nine children had an increased cardiothoracic ratio on radiography. The electrocardiogram was abnormal in every case but no child had left ventricular hypertrophy as assessed by voltage criteria. However, left ventricular hypertrophy, often gross, was found on echocardiography in 12 children and affected the interventricular septum disproportionately. Cardiac index was increased in 10 patients as a result of an increased left ventricular stroke volume rather than heart rate. Left ventricular hypertrophy was significantly greater in those on treatment for hypertension and in those with the highest cardiac index. Abnormal diastolic ventricular function was found in 6/11 children. Children with end stage renal failure have significant cardiac abnormalities that are likely to contribute to the high cardiovascular mortality in this group. Anaemia and hypertension, or its treatment, probably contribute to these changes. Voltage criteria on electrocardiogram are of no value in detecting left ventricular hypertrophy. Echocardiography must be performed, with the results corrected for age and surface area, in order to detect and follow these abnormalities.     

Rotator cuff tear: clinical experience with sonographic detection

Between June 1986 and April 1988, 86 sonographic examinations of the shoulder were performed on patients suspected of having rotator cuff tears. Major sonographic diagnostic criteria included (a) a well-defined discontinuity usually visible as a hypoechoic focus within the cuff, (b) nonvisualization of the cuff and (c) an echogenic focus within the cuff. Seventy-five patients underwent both sonography and arthrography. Compared with arthrography alone, ultrasound examinations enabled detection of 92% of rotator cuff tears (24 of 26 tears), with a specificity of 84% and a negative predictive value of 95%. Correlation was obtained in 30 of these patients who underwent surgery for rotator cuff tear or other soft-tissue abnormality. In this group, the sensitivity of sonography for detection of a tear was 93%, with a specificity of 73%, while for arthrography sensitivity was 87% and specificity was 100%. These data indicate that sonography is a useful, noninvasive screening procedure for patients suspected of having rotator cuff injury.