Meeting / Rencontre

Some "tried and true" treatments challenged during Royal College meeting

Pam Harrison

Canadian Medical Association Journal 1996; 155: 1725-1727

[en bref]


Pam Harrison is a Toronto-based freelance writer.

© 1996 Pam Harrison


In brief

The value of some longtime medical treatments was one focus of the recent Royal College annual meeting in Halifax. Physicians also witnessed some new methods and therapies being challenged.


En bref

À sa récente assemblée, à Halifax, le Collège royal s'est notamment penché sur la valeur de certains traitements médicaux de longue durée. Les médecins ont aussi été témoins de la remise en question de certaines méthodes et thérapies nouvelle vague.
The pros and cons of medical treatments and their cost received ample attention during the 65th annual meeting of the Royal College of Physicians and Surgeons of Canada in September. At the meeting the practice of medicine and the delivery of health care were examined from a newly critical perspective.

Here, in brief, are a few select answers to that question.

CT scans and dementia

The chance of reversing dementia in patients in a tertiary care outpatient population is so slim it invalidates the use of computed tomography (CT) scans in such patients, a study done in an outpatient memory clinic has determined.

In 207 patients followed for a mean period of 16 months, the prevalence of potentially reversible dementia was established at 23.7%. Only four patients improved with treatment and only three experienced a reversal of their dementia, reported Dr. Susan Freter of McGill University. Reversibility was seen only in patients with early cognitive impairment. CT scans showed potentially reversible lesions in 2.5% of the patients, she added, but none experienced reversal. Had Canadian consensus criteria concerning the use of CT scans been applied within the same cohort of patients, only 40% of the scans would have been done. "Universal CT scanning of demented patients in an [outpatient] population is not justified," the authors concluded.

Heparin nomogram

Extra vigilance is required when monitoring the heparin nomogram in frail elderly patients requiring anticoagulation medication, researchers from the Division of Geriatric Medicine at Dalhousie University reported during the meeting.

Investigators followed 48 patients who were receiving intravenous heparin for the treatment of venous thromboembolism, and determined that 27 of them were frail. "Patients who were frail spent more time outside the therapeutic range (27%) than the nonfrail (17%), and this suggests that the nomogram is less effective in getting frail patients into the therapeutic range and keeping them there," said Dr. Chris MacKnight, a fellow in geriatric medicine at the Queen Elizabeth II Health Sciences Centre.

Elderly frail patients also tended to have more swings compared with the relatively stable blood levels achieved in younger patients, and all complications, including major bleeds, recurrent embolism and death, occurred in frail patients. "We need to pay more attention to what's going on in the frail elderly or any patient who is declining in functional capacity [regardless of age]," MacKnight concluded.

CEA and colorectal cancer

The carcinoembryonic antigen (CEA) test used to follow patient response to chemotherapy for metastatic colorectal cancer has proven to be clinically worthless under objective scrutiny.

In a retrospective chart review done by the Ottawa Regional Cancer Centre, CEA levels were matched to gold-standard imaging techniques -- and surgery in some cases. Among the 17 patients whose tumour size was shown by imaging to have decreased 50% or more, CEA levels had increased in 8 of the patients, decreased in 5 and not changed in 4.

Of the 10 partial-response patients, in whom imaging showed either no change or a slight decrease in disease, 2 had an increase in CEA levels and 8 showed no change. Among the 33 patients with stable disease and no imaging evidence of disease progression, CEA levels had increased in 18 patients, decreased in 6 and not changed in 9. And in 26 patients whose disease had progressed, 14 showed an increase in CEA levels, none a decrease and 12 no change.

"The CEA test is still appropriate when used to monitor recurrence after total resection, for which it was originally indicated," said Dr. Caroline Hamm of the Ottawa Regional Cancer Centre. However, as a means for following disease response to chemotherapy "it is a totally useless clinical test" that the Ottawa Regional Cancer Centre has abandoned.

Central venous catheters

The use of central venous catheters in severely ill children causes a higher incidence of thrombotic events than is generally reported and their use should be critically evaluated in light of these new findings, physicians attending the Royal College meeting heard.

Dr. Narendra Singh, director of the pediatric intensive care unit at the Children's Hospital of Western Ontario in London, reported that in a study involving 44 patients, in whom a total of 54 lines had been inserted in the femoral, subclavian or internal jugular vein, 21 lines demonstrated clot formation. Most of it (62%) took place in lines placed in the femoral vein. Seven of the children had resultant symptoms, most commonly swelling, pain and tenderness in the leg with the femoral line.

One patient developed superior vena cava syndrome and one of the two children who had pulmonary embolism "became very ill, very quickly, as a result of the clot," said Singh.

"We're not suggesting we do away with central venous lines altogether but we should be carefully evaluating whether or not we really need a line. If we do, the child needs to be carefully monitored."

Corneal abrasion

Patching the eye following corneal abrasion neither speeds healing nor relieves pain but it does interfere with activities of daily living, a joint study by the Vancouver Hospital and Health Sciences Centre and the St. Francis Hospital in Hartford, Connecticut, has revealed.

"Intuitively, it was felt that if you patched the scratch there would be less movement and that should produce less pain and perhaps help the scratch heal a bit faster," said Dr. Anton Grunfeld, a Vancouver emergency physician.

Because there was little evidence to support patching, patients who had either a minor corneal abrasion or a minor foreign body removed from the cornea were randomized to receive topical anesthetic drops, topical antibiotics and a double eyepatch over the affected eye or the same topical regimen minus the eyepatch.

"We found no significant difference in pain perception or the amount of acetaminophen and codeine taken by the two groups in the first 24 hours," Grunfeld explained, "and there was no difference in healing times either."

However, patients who wore the eyepatch reported significantly more interference in daily activities such as driving and working. "Corneal scratches are very common and it would save a lot of money and time if we didn't put any more patches over these injuries," said Grunfeld, who added that patches are no longer used to treat corneal abrasions at his Vancouver hospital.


| CMAJ December 15, 1996 (vol 155, no 12)  /  JAMC le 15 décembre 1996 (vol 155, no 12) |