Defining quality at Catholic Healthcare West.

Catholic Healthcare West, a provider network that includes 48 acute-care facilities in California, Arizona, and Nevada, is reassessing its care of patients with acute myocardial infarction (AMI). Several studies have indicated that many patients with AMI and congestive heart failure do not receive appropriate medical treatment while hospitalized. In some cases, there is resistance among clinicians to change aspects of care--particularly prescribing habits. We sought to improve the use of aspirin and beta-blocker therapy for patients diagnosed with AMI and the use of angiotensin-converting enzyme (ACE) inhibitors for patients with congestive heart failure. We found the use of a registry that collects data on patients and their care and generates reports for system review is helpful in measuring improvement in delivery of care.

Studies of the prevalence and significance of radiolabeled bile acid malabsorption in a group of patients with idiopathic chronic diarrhea.

We studied radiolabeled fecal bile acid excretion in 11 normal subjects and 17 patients with idiopathic chronic diarrhea for three major purposes: to establish normal values for this test in the presence of increased stool volumes (induced in normal subjects by ingestion of poorly absorbable solutions); to test for bile acid malabsorption in the patients and to correlate this with an independent test of ileal function, the Schilling test; and to compare the results of the bile acid excretion test with the subsequent effect of a bile acid binding agent (cholestyramine) on stool weight. In normal subjects fecal excretion of the radiolabel was increased with increasing stool volumes. As a group, patients with idiopathic chronic diarrhea excreted radiolabeled bile acid more rapidly than normal subjects with induced diarrhea (t1/2 56 +/- 8 vs. 236 +/- 60 h, respectively, p less than 0.005). There was a statistically significant positive correlation between t1/2 of radiolabeled bile acid and Schilling test results in these patients. Although 14 of 17 patients absorbed labeled taurocholic acid less well than any of the normal subjects with comparable volumes of induced diarrhea, cholestyramine had no statistically significant effect on stool weight in the patient group, and in none of the patients was stool weight reduced to within the normal range. In summary, most patients with idiopathic chronic diarrhea have bile acid malabsorption (as measured by fecal excretion of labeled bile acid), but they do not respond to cholestyramine therapy with a significant reduction in stool weight. Although the significance of these findings was not clearly established, the most likely interpretation is that bile acid malabsorption is a manifestation of an underlying intestinal motility or absorptive defect rather than the primary cause of diarrhea.

An evaluation of the significance of microscopic colitis in patients with chronic diarrhea.

Some patients with chronic idiopathic diarrhea have an apparent nonspecific inflammation of colonic mucosa, even though their colons appear normal by barium enema and colonoscopy. This has been referred to as microscopic colitis. However, the significance of this finding is unclear, because the ability of pathologists to accurately distinguish mild degrees of abnormality has not been established. Furthermore, even if the mucosa of these patients is nonspecifically inflamed, it is not known whether this is associated with deranged colonic function that could contribute to the development of chronic diarrhea. To assess these questions, we first examined colonic biopsy specimens in a blinded fashion, comparing biopsy results from patients with microscopic colitis with biopsy specimens from subjects in two control groups. This analysis revealed that colonic mucosa from six patients with microscopic colitis was in fact abnormal. For example, their mucosa contained an excess of both neutrophiles and round cells in the lamina propria, cryptitis, and reactive changes. These and other differences were statistically significant. Second, colonic absorption, measured by the steady state nonabsorbable marker perfusion method, was severely depressed in the patients. For example, mean water absorption rate was 159 ml/h in normal subjects and was reduced to only 26 ml/h in six patients with microscopic colitis. Results of net and unidirectional electrolyte fluxes and of electrical potential difference suggested that colonic fluid absorption was abnormal because of reduced active and passive sodium and chloride absorption and because of reduced Cl/HCO3 exchange. Small intestinal fluid and electrolyte absorption was abnormally reduced in two of the six patients, suggesting the possibility of coexistent small intestinal involvement in some of these patients. We conclude that nonspecific inflammation of colonic mucosa is associated with a severe reduction of colonic fluid absorption, and that the latter probably contributes to the development of chronic diarrhea.

Fecal fat concentration in patients with steatorrhea.

We predicted that fecal fat concentration (grams of fat per gram of stool wet weight) would be higher in patients with pancreatic steatorrhea than in those with steatorrhea due to gastrointestinal disease. To evaluate this hypothesis, we examined fecal weight, fecal fat excretion, and fecal fat concentration in 19 patients with steatorrhea due to pancreatic insufficiency and in 31 patients whose steatorrhea was due to various gastrointestinal diseases. There was no consistent difference in the severity of steatorrhea or diarrhea between the two groups of patients. Fecal fat concentration, however, was usually higher in patients with pancreatic insufficiency. Fecal fat concentration may be a useful clue in distinguishing pancreatic steatorrhea from steatorrhea due to gastrointestinal disease.

An evaluation of the importance of gastric acid secretion in the absorption of dietary calcium.

Since calcium solubility is a prerequisite to calcium absorption, and since solubility of calcium is highly pH-dependent, it has been generally assumed that gastric acid secretion and gastric acidity play an important role in the intestinal absorption of calcium from ingested food or calcium salts such as CaCO3. To evaluate this hypothesis, we developed a method wherein net gastrointestinal absorption of calcium can be measured after ingestion of a single meal. A large dose of cimetidine, which markedly reduced gastric acid secretion, had no effect on calcium absorption in normal subjects, and an achlorhydric patient with pernicious anemia absorbed calcium normally. This was true regardless of the major source of dietary calcium (i.e., milk, insoluble calcium carbonate, or soluble calcium citrate). Moreover, calcium absorption after CaCO3 ingestion was the same when intragastric contents were maintained at pH 7.4 (by in vivo titration) as when intragastric pH was 3.0. On the basis of these results, we conclude that gastric acid secretion and gastric acidity do not normally play a role in the absorption of dietary calcium. Other possible mechanisms by which the gastrointestinal tract might solubilize ingested calcium complexes and salts are discussed.

Purging and calorie absorption in bulimic patients and normal women.

Self-induced purging with laxatives is common among bulimic persons, who assume that purging reduces intestinal absorption of ingested calories. However, the efficacy of purging in reducing calorie absorption has never been studied, probably because the standard calorie balance procedure is expensive and time consuming. With a recently devised method, calorie absorption during a single day was measured to determine to what extent phenolphthalein or saline purge reduced calorie absorption. In two bulimic patients who regularly used laxatives for weight control and five normal young women, even extreme purging producing 4 to 6 L of diarrhea caused calorie absorption to decrease by only about 12% of calorie intake. The theoretical basis on which laxatives are taken for weight control is unsound.

Starch blockers--their effect on calorie absorption from a high-starch meal.

It has been known for more than 25 years that certain plant foods, such as kidney beans and wheat, contain a substance that inhibits the activity of salivary and pancreatic amylase. More recently, this antiamylase has been purified and marketed for use in weight control under the generic name "starch blockers." Although this approach to weight control is highly popular, it has never been shown whether starch-blocker tablets actually reduce the absorption of calories from starch. Using a one-day calorie-balance technique and a high-starch (100 g) meal (spaghetti, tomato sauce, and bread), we measured the excretion of fecal calories after normal subjects had taken either placebo or starch-blocker tablets. If the starch-blocker tablets had prevented the digestion of starch, fecal calorie excretion should have increased by 400 kcal. However, fecal calorie excretion was the same on the two test days (mean +/- S.E.M., 80 +/- 4 as compared with 78 +/- 2). We conclude that starch-blocker tablets do not inhibit the digestion and absorption of starch calories in human beings.

Percutaneous central venous catheterization performed by medical house officers: a prospective study.

We prospectively determined the complications of percutaneous central venous catheterizations performed by medical house officers in 302 patients. We also analyzed the factors affecting the success and complication rates of such invasive procedures. The central vein was successfully catheterized in 363 (77%) of 470 attempts. The internal jugular and subclavian vein approaches were significantly more successful (86%) than the external jugular vein approach (61%, P less than 0.001 by chi 2). The success rate improved significantly when catheterization was attempted under elective circumstances (P less than 0.003) and also after the vein was initially located with a small-gauge needle (P less than 0.001). Our results suggest that efforts should be abandoned after the third unsuccessful pass with a large-gauge needle in the same site. Complications of catheter insertion included bleeding (ten patients), hematoma (15 patients), inadvertent arterial punctures (14 patients), iatrogenic pleural effusions (four patients), and pneumothoraces (eight patients). No complications appeared to have a major adverse effect on a patient's clinical course. The inexperienced operator (fewer than 25 prior catheterizations) has a success rate equal to that of the more experienced operator (more than 25 prior catheterizations), but he may be more likely to produce a complication. Medical house officers can perform percutaneous central venous catheterizations with a high rate of success and a low risk to the patient.