Double j stents Health Dictionary

A scienti?c study in which di?erent patients receive a di?erent drug, the same drug at a different dose, or a placebo – with neither the investigators assessing the outcome nor the subjects being treated knowing which of these the latter are receiving. The aim is to remove any hint of bias due to the investigators’ or patients’ preferences or preconceptions. The results are analysed after all the data have been collected and the code has been broken. Trials should have a separate supervising committee, the members of which know the code but do not take part in the study. Their job is to check the results at intervals so they can stop the trial if one arm of treatment is clearly better than another. Otherwise, it would be unethical to continue. (See INTERVENTION STUDY.)... double blind trial

See SQUINT.... double vision

A type of controlled trial that tests the effectiveness of a treatment or compares the benefits of different treatments.

In double-blind trials, neither the patients nor the doctors assessing the treatments know which patients are receiving which treatment.

This eliminates any expectations about which treatment will be most effective.... double-blind

the principle that, where it is foreseen that a single action will have both a good and a bad outcome, a person may perform such an action provided that (a) he or she intends only the positive outcome, (b) the bad outcome is not disproportionate to the good, and (c) the good outcome is not a direct consequence of the bad. The classic example occurs where a terminally ill patient requires high doses of opiates for pain relief that may also depress respiratory function and hasten his or her death. In such a case the law holds that the doctor may supply the necessary dosage without this being considered tantamount to *euthanasia, even though the outcome will be the same, i.e. the morality of the action does not lie in its consequences (see consequentialism).... doctrine of double effect

a technique usually used in X-ray examinations of the bowel. Barium sulphate *contrast medium (first contrast) is used to coat the bowel wall. The bowel is then distended with gas (second contrast). The X-ray images obtained give exquisite detail of the lining of the gut. See also barium enema; barium swallow and meal.... double contrast

the situation in which a patient (the inducer) presents with delusional symptoms that he or she believes to be shared by someone else who is incapable of expressing them (typically a child or a pet). This is different from a *delusion by proxy, in which the inducer does not claim to be experiencing the symptoms himself or herself. The term was introduced in 2015 by Peter Lepping, Mark Rishniw, and Roland Wolfgang Freudenmann. Compare folie à deux.... double delusion

(DORV) a congenital defect of the heart in which both the aorta and the pulmonary artery arise predominantly from the right ventricle anterior to the ventricular septum with an associated *ventricular septal defect (VSD). The relationship between the site of the VSD and the great arteries must be taken into account for surgical repair. DORV can be associated with chromosomal defects.... double-outlet right ventricle

see uterus didelphys.... double uterus

see stent.... pig-tail stents