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Biomedical subjects

K L Cheung

Publications and source records attributed to K L Cheung.

At least 127 records · Page 7Linked to original sources

Adverse effect of topical methylsalicylate ointment on warfarin anticoagulation: an unrecognized potential hazard.

The adverse effect of topical methylsalicylate ointment on warfarin anticoagulation is studied in 11 patients. All patients had an abnormally elevated international normalized ratio after significant usage of topical methylsalicylate ointment as obvious from both the clinical history and a positive blood level of salicylate. Out of the 11 patients, 3 had bleeding manifestation; 2 with bruises and 1 with gastrointestinal bleeding. It is concluded that topical methylsalicylate ointment should be prescribed with care to patients on warfarin and excessive usage is to be avoided since potentially dangerous drug interaction could occur.

Administration, Topical↗

False detection of left atrial thrombus by the angiographic sign of "neovascularity".

"Neovascularity" in the region of the left atrial appendage was demonstrated by coronary arteriography preoperatively in five patients with mitral valve disease and was attributed to the presence of thrombus in the left atrium. Subsequently, they underwent surgery, but thorough inspection of the left atrium did not reveal thrombus in any of the five patients. The presence of neovascularity without apparent thrombosis or false detection may be a result of tissue reaction and organization in an effort to resorb the thrombus.

Adult↗

Biventricular perforation by a temporary pacing electrode: recognition from the lateral chest radiograph.

A temporary pacing electrode was inserted in a patient with severe calcific aortic stenosis complicated by complete atrioventricular block. Despite normal pacing and sensing function, a diagnosis of myocardial perforation was made on the basis of a lateral chest radiograph. Neither the surface electrocardiogram nor the frontal chest radiograph suggested evidence of myocardial perforation, and echocardiographic diagnosis was limited by poor echogenicity of the patient. Biventricular perforation with pericardial effusion were documented at operation.

Cardiac Pacing, Artificial↗

Late metabolic acidosis and poor weight gain in moderately pre-term babies fed with a casein-predominant formula: a continuing need for caution.

When our neonatal unit opened in 1984 our formula feeding policy for moderately preterm babies was for casein-predominant rather than "humanized" whey-predominant milk formulae to be given. However, an early cluster of cases of late persistent metabolic acidosis prompted an investigation into the acid-base status and weight gain in preterm infants. This study of 70 healthy, moderately preterm (32-35 weeks) Chinese babies has convincingly shown that a casein-predominant low protein formula is associated with significant metabolic acidosis, persisting sometimes for as long as 8 weeks, and poor weight gain when compared with infants fed on either a humanized or a special low-birthweight formula. This is an important message for the many neonatal units in developing countries where the cost of humanized formulae might initially seem prohibitive, encouraging instead casein-predominant formulae when breast milk is not available. Any additional expense incurred in using humanized formulae will be compensated for by the shortened time spent in hospital.

Acidosis↗

Infected atrial myxoma.

A patient is reported in whom a left atrial myxoma was found to be infected with Staphylococcus aureus. The clinical presentation, diagnosis and treatment are described and discussed.

Echocardiography↗

Combined use of warfarin and adjusted subcutaneous heparin during pregnancy in patients with an artificial heart valve.

Adjusted subcutaneous heparin was used for thromboembolism prophylaxis during 18 pregnancies in 16 women with an artificial heart valve. Oral warfarin was replaced by subcutaneous heparin as soon as pregnancy was confirmed. The dosage of heparin was adjusted to maintain a partial thromboplastin time at 1.5 times the control value and treatment was administered during the first trimester and the last 3 weeks of gestation. Warfarin was used between the 13th and 37th week. There were no maternal thromboembolic complications and none of the live-born infants showed congenital malformations, indicating that this regimen is effective. However, there were nine spontaneous abortions, including five that occurred in the first 12 weeks. The early abortions were probably related to warfarin exposure at the beginning of pregnancy. The preconception replacement of warfarin by heparin in these patients may be indicated.

Abortion, Spontaneous↗

Unruptured right coronary sinus to left ventricle aneurysm diagnosed by cross sectional echocardiography.

A 37 year old Chinese man presenting with features of chest infection was diagnosed as having severe aortic regurgitation. Cross sectional echocardiography showed an intact right coronary sinus of Valsalva aneurysm, which protruded into the left ventricle. The changes in appearance of the aneurysm during the cardiac cycle were recorded by cross sectional echocardiography. The opening of the aneurysm was successfully closed and the aortic valve replaced with a mechanical prosthesis.

Adult↗

Warfarin versus dipyridamole-aspirin and pentoxifylline-aspirin for the prevention of prosthetic heart valve thromboembolism: a prospective randomized clinical trial.

In a prospective, randomized, parallel study, two regimens of platelet-suppressant therapy (PST)--dipyridamole-aspirin and pentoxifylline-aspirin--were compared with standard oral anticoagulation with warfarin in the prevention of prosthetic heart valve thromboembolism. In the entire group of 254 patients followed for 395.6 patient-years, the thromboembolic rate was significantly less in the warfarin group (warfarin vs dipyridamole-aspirin, p less than .005; warfarin vs pentoxifylline-aspirin, p less than .05). Subgroup analysis disclosed that, in patients with isolated mitral valve replacement, warfarin was superior to both of the PSTs with respect to the prevention of thromboembolism (warfarin vs dipyridamole-aspirin, p = .005; warfarin vs pentoxifylline-aspirin, p less than .05). Furthermore, a significant number of our patients could not tolerate the antiplatelet agents. However, in the rare situation in which repeated significant bleeding occurs despite careful adjustment of the dosage of warfarin, PST may be an acceptable alternate method of thromboembolism prophylaxis.

Adult↗

Is cardiac catheterisation necessary before valvular surgery?

The results of 269 patients who had undergone valvular operations during and 18-month period (January 1, 1980, to June 30, 1981) were analysed. One hundred and seventy-four patients referred for surgery had undergone routine cardiac catheterisation elsewhere, and these, together with four electively catheterised patients, constituted a group representing the conventional approach. Ninety-one patients were assessed only by clinical and non-invasive methods, including echocardiography, and were subjected to surgery without catheterisation. The two groups were comparable in their major clinical characteristics including age, sex ratio, functional class, previous history of closed mitral valvotomy, aetiology of valve lesions, and type of operative procedure performed. There was no discordance between operative finding and preoperative assessment, except in two patients of the catheterised group. Hospital mortality was acceptably low and was comparable between the two groups. Cardiac catheterisation is, thus, no longer necessary in the majority of patients undergoing surgery for valvular heart diseases.

Adult↗