Hodgson et al. (A-14) conducted a study in which they induced gastric dilatation in six anesthetized dogs maintained with constant-dose isoflurane in oxygen. Cardiopulmonary measurements prior to stomach distension (baseline) were compared with measurements taken during .1, .5, 1.0, 1.5, 2.5, and 3.5 hours of stomach distension by analyzing the change from baseline. After distending the stomach, cardiac index increased from 1.5 to 3.5 hours. Stroke volume did not change. During inflation, increases were observed in systemic arterial, pulmonary arterial, and right atrial pressure. Respiratory frequency was unchanged. PaO2 tended to decrease during gastric dilatation. What are the experimental units? The blocks? Treatment variable?

Response variable(s)? Can you think of any extraneous variable whose effect would contribute to the error term? Construct an ANOVA table for this study in which you identify the sources of variability and specify the degrees of freedom.