The cost and efficiency of hospital care provided by primary care physicians and medical subspecialists.

There is a perceived excess of subspecialists compared with primary care doctors, but there are few severity-adjusted data that characterize the care provided by these physician groups. In a nationwide hospital network, we studied outcomes of 17,185 patients who were hospitalized for 1 of 9 common internal medicine illnesses. For 4 of 9 conditions, the subspecialists treated more severely ill (P < .001) patients. The raw total charges for their care were higher (P < .002) for 4 of 9 conditions and longer stays were required for 2 conditions. After adjusting for severity of illness, differences between the physician groups became minimal. In nine-severity adjusted medical illnesses, subspecialists and primary care physicians provide care that produces similar results for length of stay, charge, and mortality. Health care manpower projections should be re-evaluated in light of this information.

Chronic inflammation and cancer: potential role of Bcl-2 gene family members as regulators of cellular antioxidant status.

The incidence of cancer is increased in all gastrointestinal (GI) tissues as a result of chronic inflammation. These cancers may develop in cells that are selected for resistance to inflammatory products by virtue of overexpressing the antioxidant protein Bcl-2 or other Bcl-2 gene family members that have antioxidant activity. Unfortunately, Bcl-2 also functions as an anti-apoptotic. Bcl-2 overexpression can increase cellular lifetime and increase the likelihood that other cancer-related mutations will accumulate in individual cells. Thus, Bcl-2 expression is cytoprotective, but its expression also increases the risk of cancer incidence. This is perhaps more evident in the GI tract, which is exposed to more potential mutagens relative to other tissues.

Immunohistochemical evaluation of Bcl-2 gene family expression in liver of hepatitis C and cirrhotic patients: a novel mechanism to explain the high incidence of hepatocarcinoma in cirrhotics.

OBJECTIVE: The purpose of this study was to determine whether there is an increase in expression of bcl-2 and related bcl-2 gene family members bcl-X and bax in liver biopsy samples obtained from patients with either hepatitis C infection or cirrhosis. Bcl-2, bcl-X, and bax, as well as other bcl-2-related proteins, function coordinately through homo- and heterodimerization to regulate apoptosis. Bcl-2, which is characterized as an antiapoptotic, also functions as an antioxidant. We hypothesized that a mechanism that could account for increased hepatocellular carcinoma in patients with hepatitis C and cirrhosis is selection of bcl-2 expressing cells. This selection would be due to the capacity of individual cells to resist the toxic effects of inflammatory byproducts, specifically reactive oxygen species. METHODS: Sections cut from archived liver biopsy samples embedded in paraffin were probed with antibody specific for bcl-2, bcl-X, or bax. Liver samples were from normal (N = 5), hepatitis C patients (N = 19), and cirrhotics (N = 10). Percent positive staining and intensity of staining were judged independently for hepatocytes, bile ducts, mononuclear cells, and Kupffer cells. RESULTS: Bcl-2 expression was evident in bile ducts and mononuclear cells of hepatitis C patients, but was not commonly present in hepatocytes (two of 10). In the cirrhotic liver, bcl-2 expression was also detected in bile ducts and mononuclear cells, but in contrast to hepatitis patients was also expressed in hepatocytes (nine of 10). A similar pattern of expression was evident for bcl-X, but in general the level of expression was limited relative to that of bcl-2. Bax expression was infrequently present in sections from any of the three patient groups. CONCLUSIONS: The data indicate that bcl-2 expression is elevated in the liver of cirrhotics, but is not evident in the liver of hepatitis C patients. This increase in expression of bcl-2 in cirrhotic patients may correlate with development of hepatocellular carcinoma given the anti-apoptotic/oncogenic potential of bcl-2.

The utility of hospital administrative data for generating a screening program to predict adverse outcomes.

A system to predict which patients will suffer medical complications or poor financial outcomes during a hospitalization would be very useful to providers of medical care. To develop such a system, we applied two previously developed indices that predict in-hospital complications to all 321,558 adult patients discharged from our hospital network. The indices identified 26,377 patients (8.2%) who experienced one or more medical complications. For these patients, high-risk admitting diagnoses were identified. We tabulated 4235 admitting diagnoses and focused on 26 (0.6%) diagnoses that were high-risk and high-volume for complications. We found that 25% of patients with these admitting diagnoses experienced complications during hospitalization. Prevention of these complications could have saved 1241 hospital days, 11 lives, and $10.5 million. Administrative data available at the time of admission can be useful in identifying the small subset of patients who are likely to experience adverse clinical outcomes during a hospitalization and those who are likely to generate adverse financial outcomes for the hospital.

Prokinetic activity of nizatidine: implications for the management of patients with gastroesophageal reflux disease.

Gastroesophageal reflux is a common condition caused mainly by motility disorders of the upper gastrointestinal tract. The most effective therapy combines acid suppression with a promotility agent. Nizatidine is a well-tolerated and effective histamine-2 (H2)-receptor antagonist used to suppress gastric acid secretion. Animal and human studies have conclusively demonstrated that nizatidine also has prokinetic activity comparable to that of cisapride, and its effect is evident <1 hour after administration of doses commonly used in clinical practice. This prokinetic activity occurs through noncompetitive inhibition of acetylcholine; this inhibition approximates the inhibition caused by neostigmine. Nizatidine appears to possess a prokinetic mechanism that may be helpful in treating patients with gastroesophageal reflux.

Answers to 10 key questions on diverticular disease of the colon.

Diverticular disease is common in industrialized countries, and will become more prevalent in the future. Although it is usually a benign condition, treatment with high-fiber diet may prevent complications such as infection, stricture, or bleeding.

Does intra-abdominal fluid increase the resting energy expenditure?

In patients with intra-abdominal fluid collection, caloric needs are based on an estimated dry weight. This is done because intra-abdominal fluid has been assumed to be metabolically inactive. One recent study of patients with slowly resolving ascites suggested otherwise. In our study, the effect of intra-abdominal fluid on the resting energy expenditure (REE) and apparent lean body mass was determined in 10 stable patients requiring peritoneal dialysis. For each subject, in both the empty and full state, we measured REE by indirect calorimetry, and body composition by the bioelectric impedance method. In the full state, the VCO2 was significantly increased (210 +/- 11 versus 197 +/- 9 mL/min, P < 0.02) compared with the empty state. This caused an increase in the calculated resting energy expenditure (1531 +/- 88 kcal/d empty versus 1593 +/- 94 kcal/d full, P < 0.05). The magnitude of increase in REE was similar to the expected calories derived from glucose absorbed out of the dialysate. Estimates of body fat, lean body mass, and total water also were not affected by the intra-abdominal fluid. We conclude that intra-abdominal fluid will not affect the measured REE and hence may be considered to be metabolically inactive.

The effect of gastroenterology training on the efficiency and cost of care provided to patients with diverticulitis.

BACKGROUND & AIMS: National trends emphasize the need for cost-efficient medical care with no diminution in quality. The most appropriate role for various physician groups has yet to be determined. The aim of this study was to investigate the efficiency of medical care provided by family practitioners (FPs), internists (IMs), and gastroenterologists (GIs) for acute diverticulitis. METHODS: All medicare hospitalizations from 1990 to 1993 in Illinois caused by acute diverticulitis, with FPs, IMs, or GIs as the primary attending physician, were included in the study. RESULTS: The primary attending physician was an FP in 1019 cases, an IM in 2535 cases, and a GI in 163 cases. The age and sex distributions were similar. The length of stay was significantly shorter (P < 0.0001) for GIs (7.4 +/- 6 days) than for FPs (7.9 +/- 14 days) or IMs (8.6 +/- 7 days). Readmission rate was significantly less (P < 0.03) for GIs (4.5%) than for FPs (7.7%) or IMs (10.0%). No significant differences were noted in complication rates or mortality. CONCLUSIONS: Patients with diverticulitis treated by GIs have a shorter hospital stay and a lower risk for readmission than patients treated by FPs or IMs. This improved quality of care should be considered by managed care organizations because they decide the role of various physician groups.

The effect of gender on the rates of hospitalization for gastrointestinal illnesses.

OBJECTIVES: Over the years, reports have indicated that many medical illnesses show a predilection for one of the genders. Such observations are important, in part, because they may provide insights into the pathophysiology of the illness. Unfortunately, these observations often have been based on small subsets of the population, and hence may contain sampling bias. METHODS: Our study reviews computerized data regarding all hospitalizations in the State of Illinois over a 1-yr period for all gastrointestinal illnesses. RESULTS: We noted that the gender distribution for all gastrointestinal illnesses is highly (p <0.001) significant. We found 20 conditions with predominant (p <0.01) female representation, including cholelithiasis, diverticulosis, and nonspecific enteritis. We also noted eight conditions with predominately (p <0.01) male representation, including acute appendicitis, inguinal hernia, chronic liver disease, and duodenal ulcer. Twenty remaining conditions had no significant differences in female/male distribution: those included ulcerative colitis, gastrointestinal hemorrhage, and esophageal illnesses. CONCLUSIONS: We conclude that the use of a large, computer-based database permits the observation of hospitalization rates based on gender, and that such differences may have impact on the perceptions and practice of medical care.

Factors influencing bowel function following total abdominal colectomy.

PURPOSE: The purpose of this study was to determine which factors influenced bowel function following total abdominal colectomy. METHODS: Thirty-two patients who had undergone total abdominal colectomy were studied with regard to factors that are classically thought to influence bowel function, namely, residual stump length, transit time, and rectal stump manometry. In a limited subset of patients, anal manometry was done also. RESULTS: Transit time was the best predictor of bowel function following total abdominal colectomy. This was followed by stump length. If transit time was short, then stump length became important in predicting the occurrence of diarrhea following total abdominal colectomy. CONCLUSIONS: Two factors have an important influence on bowel function following total abdominal colectomy: transit time and rectal stump length. Rectal stump length is an anatomic factor that can be controlled by the surgeon. In total abdominal colectomy, rectal stump length of at least 20 cm is necessary if the patient is to have satisfactory postoperative bowel function. This may not always be possible. In these patients, modification of diet to influence transit time and methods to increase rectal compliance will be necessary.

Elevated breath ethane levels in active ulcerative colitis: evidence for excessive lipid peroxidation.

OBJECTIVE: Reactive oxygen species (ROS) may be a major cause of tissue injury in ulcerative colitis (UC). One possible mechanism for ROS-mediated tissue injury is lipid peroxidation. Breath ethane and pentane excretion are noninvasive means for measuring peroxidation of omega-3 and omega-6 polyunsaturated fatty acid, respectively. Hence, we measured breath ethane in 17 subjects with active UC and correlated the results with disease severity. METHODS: Breath samples for ethane and pentane analysis were collected every 2 weeks, and rectal biopsies were obtained monthly to assess for chemiluminescence, a marker of ROS. Ethane and pentane concentrations (nmol/L) were measured by gas chromatography, and mucosal chemiluminescence was measured spectrophotometrically. Data were compared to control values (C) from healthy subjects. Disease activity was assessed both clinically and endoscopically. RESULTS: Ethane excretion was significantly elevated in patients (UC, 0.45 +/- 0.04; C, 0.33 +/- 0.06; p = 0.013). Ethane excretion was positively correlated with endoscopic score (r = 0.45; p < 0.05), symptom score (r = 0.34; p < 0.05), disease activity (r = 0.36, p < 0.05), and chemiluminescence (r = 0.65; p < 0.001). Pentane levels did not correlate with any of the clinical measurements. Chemiluminescence in the rectal tissue was positively correlated with endoscopic score (r = 0.71; p < 0.05) and disease activity (r = 0.61; p < 0.01). CONCLUSIONS: Tissue damage in UC may be ROS-induced lipid peroxidation. Disease activity can be assessed noninvasively by breath ethane excretion.

Effect of dietary oat and soy fiber on bowel function and clinical tolerance in a tube feeding dependent population.

OBJECTIVE: The role of fiber in tube feeding products has not clearly been defined. While some studies suggest that fiber can increase stool weight and bowel transit time in acutely ill patients, there is less information in stable patients receiving chronic enteral nutritional support. DESIGN: Using a crossover study design, we investigated the effect of 28.8 g/day of a 50% soy and 50% oat fiber combination in 10 medically stable residents of a chronic care facility. Subjects were randomized to initially receive 10 days of either Isocal HN or Ultracal, which are identical in composition except Ultracal contains 14.4 g/L of fiber. After the first 10-day study, subjects underwent a washout followed by a second 10-day study using the other product. Fecal dye markers were used to identify appropriate collection times. RESULTS: Fiber significantly increased the number of bowel movements per day (0.9 +/- 0.4 vs 0.5 +/- 0.2, p < 0.05) and fecal weights (57 +/- 31 vs 32 +/- 25 g/day, p < 0.05). Fiber also caused a significant increase in fecal nitrogen output (110 +/- 65 vs 75 +/- 74 mg/day, p < 0.05) and fecal energy (141 +/- 73 vs 76 +/- 62 kcal/day, p < 0.05). Fiber did not affect fecal moisture, gastric emptying, or intestinal transit time. CONCLUSION: We conclude that the addition of a combination of soy and oat fiber to tube feeding material is well tolerated, and promotes regular bowel movements without altering the rate of gastric emptying or intestinal transit time.

Nutrition aspects of continuous ambulatory peritoneal dialysis: a review.

Continuous ambulatory peritoneal dialysis (CAPD) is an increasingly popular alternative to hemodialysis. Nutrition practitioners in the in- and outpatient setting must be knowledgeable about specific nutritional considerations in these patients. In this paper, we briefly review factors which play a role in the malnutrition often encountered in end-stage renal disease, and focus on metabolic abnormalities, nutritional requirements, and nutritional assessment of patients undergoing CAPD. Urea kinetic modeling as an adjunct to nutritional assessment is explained in detail.

Breath pentane is a marker of acute cardiac allograft rejection.

Breath pentane, a product of lipid peroxidation that serves as a noninvasive marker of tissue inflammation and injury, was measured as a potential marker of acute cardiac allograft rejection. We prospectively studied 37 consecutive outpatients with stable cardiac allograft function. Breath pentane levels were measured with gas chromatography, and the results were compared the findings from routine surveillance endomyocardial biopsy. Data analysis was performed with the receiver operating characteristic curve and negative and positive predictive values. Statistical methods include analysis of variance and two-sample t-tests. Histopathologic findings consistent with rejection were present on endomyocardial biopsy in 52% of the subjects. Pentane levels in healthy control subjects did not differ from those of patients undergoing transplantation without rejection. Average pentane excretion for subjects with mild rejection (4.2 +/- 2.8 nmol/L) or moderate rejection (5.4 +/- 2.6 nmol/L) exceeded that seen in subjects who did not have rejection (1.7 +/- 0.9 nmol/L) (p < 0.02). A pentane cutoff value of 2.43 nmol/L, chosen to give the highest negative predictive value, had a sensitivity of 0.80. We concluded that breath pentane excretion is a sensitive noninvasive screening test for the detection of cardiac allograft rejection.

Inflammatory pseudotumor of the liver: appearance on MRI.

Inflammatory pseudotumor of the liver is a rare entity; fewer than 50 cases have been reported in the world literature. Its appearance on both computerized tomography (CT) and ultrasound have been previously described. To our knowledge, this is the first report of its appearance on magnetic resonance imaging (MRI). The lesion demonstrated increased signal intensity on T-1 and T-2 spin-echo and inversion recovery (STIR) sequences in relationship to normal liver. The signal characteristics, however, were nonspecific and diagnosis required biopsy confirmation. There was spontaneous resolution with conservative management, and this was documented on follow-up CT and MRI.

Elevated breath pentane in heart failure reduced by free radical scavenger.

UNLABELLED: Pentane, a product of lipid peroxidation, has been detected in situations involving ischemic injury. Such injury may be limited if lipid peroxidation can be controlled by antioxidants. The role of lipid peroxidation in chronic heart failure (CHF) was assessed by measuring breath pentane in patients with CHF vs. age matched controls. The effect of a free radical scavenger on pentane released during CHF was also measured. Pentane levels were correlated with the daily dose of captopril, a sulfhydril-containing drug used to treat CHF, which is an angiotensin converting enzyme inhibitor. To separate the scavenging effects of captopril from the pharmacologic effects of converting enzyme inhibitors, a crossover study using a nonsulfhydril inhibitor was used. Patients with CHF excreted (p < 0.005) high concentrations of pentane (5.7 +/- 2.1 vs. control 3.6 +/- 1.2 nmol/l). Patients treated with captopril also had significantly higher (p < 0.05) excretion of pentane than the control patients (4.7 +/- 1.3 vs. 3.6 +/- 1.2 nmol/l). The dose of captopril was inversely proportional to the concentration of pentane excreted (r = 0.55, p < 0.05). Pentane excretion during captopril therapy was significantly lower before (p < 0.01) and after (p < 0.02) nonsulfhydril inhibitor therapy. CONCLUSION: breath pentane is elevated in CHF and it can be reduced by a free radical scavenger. This reduction of pentane excretion is not a converting enzyme inhibitor class effect.

Pulmonary pentane excretion increases with age in healthy subjects.

Excessive lipid peroxidation occurs in various diseases. However, even in health low levels of lipid peroxidation can be detected by measuring the pulmonary excretion of pentane. Lipid peroxidation has been postulated to be one of the causes of the ageing process. In order to test whether pentane excretion is related to age, we measured breath pentane in 47 healthy subjects (ages 21-79). We also measured serum levels of the antioxidants tocopherol, retinol, lycopene, beta carotene, ascorbate and zinc. We found that pentane excretion significantly (P < 0.05, r = 0.32) increased with age. Of the six antioxidants measured, only lycopene decreased significantly (P < 0.05, r = -0.47) with age, however, this decline did not statistically correlate with pentane excretion. The remaining five antioxidants either remained stable or increased over the age range studied. We conclude that lipid peroxidation, as assessed by pentane excretion, increases with advancing age but that this increase is independent of dietary antioxidant levels.

Beta-carotene decreases markers of lipid peroxidation in healthy volunteers.

We previously showed that daily intake of beta-carotene, a nontoxic antioxidant, reduces lipid peroxidation as assessed by serum lipid peroxide levels. An alternative method to detect lipid peroxidation is the measurement of pentane in breath. Pentane is a five-carbon hydrocarbon that is released when an omega-6 unsaturated fatty acid undergoes peroxidation. The aim of this study was to see whether graded doses of beta-carotene would affect breath pentane excretion in normal subjects placed on a carotenoid-free liquid diet for two weeks. The subjects were then repleted with either 15 (n = 7) or 120 mg (n = 8) of beta-carotene daily for four weeks while continuing the same diet. Serum beta-carotene and breath pentane were measured before and after beta-carotene refeeding. Lipid peroxidation, as assessed by gas-chromatographic measurement of breath pentane, was significantly (p < 0.05) reduced by daily supplements of 120 mg beta-carotene (from 3.7 +/- 0.9 to 2.2 +/- 1.4 nmol/l). However, the decline in pentane exhalation observed with the 15-mg beta-carotene dose did not achieve statistical significance (p = 0.13).

Oral diet does not alter pulmonary pentane or ethane excretion in healthy subjects.

Ethane and pentane are alkanes that are excreted through the lungs to a small degree in healthy subjects. These gasses are produced from the peroxidation of unsaturated fats which are found both in body tissues and in foods. These gasses are excreted in larger amounts by patients with increased production of reactive oxygen metabolites, including those with inflammation or ischemia. Thus, detection of these gasses in excessive quantities is considered evidence for lipid peroxidation. However, the effects of dietary factors on these measurements have not been defined. To define the effects of eating on the pulmonary excretion of these alkanes, 29 healthy subjects were fed a standardized liquid diet (1060 kcal, 12.9 g linoleic acid and 385 mg linolenic acid) after an overnight fast. Breath alkanes were measured at 0, 1, 3, and 6 hours. All subjects had normal vitamin E (1.11 + 0.26 mg/dl), retinol (64 +/- 14 micrograms/dl), beta carotene (27 +/- 21 micrograms/dl), lycopene (23 +/- 12 micrograms/dl) and zinc (81.9 +/- 13.5 micrograms/dl) levels. No statistically significant changes in either alkane were noted relative to the fasting level. We conclude that oral diet does not alter pulmonary ethane or pentane excretion in healthy subjects.