Judgment has been defined as the ability to make correct decisions with uncertain, incomplete, or inconsistent information. Decision analysis is a scientific method of choosing between trade-offs. This review provides evidence that the model of decision analysis adequately represents clinical problems and that the use of decision analysis can improve clinical judgment. The technique of analyzing decisions using a decision tree model is reviewed. Using the decision tree model, a decision consists of specifying the options, specifying the outcomes associated with each option, assigning probabilities to those outcomes when they are not known with certainty, and assigning values or utilities to those outcomes. Surgical decisions can be described by a limited number of decision trees despite a much larger number of clinical problems. A model of the surgical decision making process, consistent with the analytical decision tree model, details steps useful in clinical decision making. The surgeon determines whether the characteristics of the patient match those of the typical patient with the condition. If so, the standard solution is recommended. If not, the surgeon concentrates on assessing or revising the specific probabilities or utilities that are different. If the best option is suboptimal, consideration is given to more aggressive diagnosis or to a therapy that offers the potential for a better outcome, but at a risk. The recommendations of surgeons for 6 patient management problems was compared to the analytical solutions using their own subjective estimates of probabilities and utilities. Decision analysis provided a net gain in accuracy in all 6 problems. Decision analysis was also significantly more accurate than the conventional second opinion program.(ABSTRACT TRUNCATED AT 250 WORDS)

Decision Support Techniques↗

PubMedDate not supplied

Role of the polar trophectoderm in determining the pattern of early post-implantation morphogenesis in mammals: evidence from development of the short-tailed field vole, Microtus agrestis.

The peri-implantational embryogenesis in the field vole, Microtus agrestis, is described. Implantation is interstitial, as it is in the mouse, but egg cylinder formation occurs by invagination of the blastocyst's embryonic pole and not (as in the mouse) by formation of a multilayered extra-embryonic ectoderm. This difference can be attributed to loss in the field vole of the central portion of the polar trophectoderm at the time of blastocyst attachment. In comparing early postimplantation development of mammalian species, three morphogenetic variables should be considered: (i) continued proliferation of polar trophectoderm; (ii) mechanical constraints on the direction of its growth; (iii) variations in the degree to which polar trophectoderm is maintained intact after implantation.

Animals↗

PubMedDate not supplied

Red cell sodium concentration as an indicator of cellular injury in clinical shock.

Red cell sodium concentration has been found to be elevated in shock. The significance of this change relative to survival and the possible sources for this increase were examined. Twenty patients in shock had red cell sodium levels compared to shock-related variables and to conditions known to increase red cell sodium levels in vitro. There was no difference noted in red cell sodium elevations between survivors and nonsurvivors. There was a highly significant correlation with transfusions of banked blood and a significant correlation with the administration of digitalis. There was no correlation with the type, duration, or severity of shock. Changes in the sodium gradients across red cell membranes in clinical shock are not good indicators of the general cellular injury of shock.

Blood Transfusion↗

PubMedDate not supplied

Reactivation of ocular toxoplasmosis in fellow unaffected eye.

PURPOSE: To report a case of reactivation of ocular toxoplasmosis in fellow unaffected eye. METHODS: Case report. RESULTS: A 15 year old girl, known to have right ocular toxoplasmosis previously, has presented with one week history of sudden left visual deterioration and pan uveitis. Her condition was improved on intensive steroid treatment. CONCLUSIONS: Reactivation of such lesion in fellow unaffected eye is quite rare. Various choices of treatment are available and there are also different techniques to treat. A review of treatment based on this pathology is briefly discussed.

Adolescent↗