The effect of oral bases on enteral aluminum absorption.

Physicochemical considerations suggest that citrate may potentiate gastrointestinal aluminum absorption via the formation of an aluminum citrate moiety. We tested this hypothesis and also studied whether sodium bicarbonate would have a similar effect. Eight healthy adults each partook of four oral regimens: aluminum alone, aluminum plus sodium bicarbonate, aluminum plus citrate (as Shohl's solution), and citrate alone. Twenty-four hour urine collections were obtained immediately preceding and during the second day of each medication period for determination of aluminum content. A significant but similar increment in urinary aluminum occurred with both aluminum alone and aluminum plus sodium bicarbonate, while only a small increment was noted with Shohl's solution alone. The rise in urinary aluminum obtained with aluminum plus Shohl's solution, however, was nearly eight times that seen with either aluminum alone or aluminum plus sodium bicarbonate (327 micrograms vs 45 micrograms and 41 micrograms, respectively). Citrate thus appears to augment gastrointestinal aluminum absorption markedly, an effect not shared by an equivalent dose of sodium bicarbonate. Citrate administration to patients with renal failure who are also taking aluminum-containing medication may be harmful.

The effect of gastric bypass surgery on hypertension in morbidly obese patients.

BACKGROUND: Hypertension is the most common medical disorder associated with obesity. The relationship between dietary weight loss and the reduction of blood pressure is well established. However, the effect of gastric bypass surgery on blood pressure has not been well studied. METHODS: We evaluated the relationship between weight loss and blood pressure in patients with diastolic hypertension who had gastric bypass surgery for morbid obesity. Patients were defined as hypertensive if taking antihypertensive medication or if both the preoperative office and mean hospital diastolic blood pressures were greater than 90 mmHg. Two of the authors (J.L.C., M.E.R.), blinded to all postoperative weights, classified the follow-up hypertensive status into one of four categories: resolved, improved, no change, or worse. The relationship between postoperative changes in blood pressure status and mean weight loss, percent excess weight loss, and body mass index were examined using a one-way analysis of variance. The relationship between postoperative weight loss and blood pressure was assessed in the baseline normotensive population using linear regression analysis. RESULTS: There were 45 patients with diastolic hypertension; 91% were taking an antihypertensive medication. The mean follow-up was 39 months. The mean preoperative weight was 137 kg and the mean weight loss at 1, 12, and 24 months following surgery was 13, 21, and 45 kg, respectively. Twelve months after surgery, hypertension had resolved in 22 patients (54%) and had improved in six patients (15%). These findings persisted through 48 months postoperatively. There was a significant relationship between the percentage of excess weight lost and improvement of hypertension at the 6-month and 12-month follow-up visits. There was also a significant relationship between the body mass index and improvement of hypertension at the 1-month, 12-month, 24-month, and 48-month follow-up visits. In the baseline normotensive patients there was not a significant relationship between our weight loss measures and changes in blood pressure. CONCLUSIONS: We conclude that postoperative weight loss in patients undergoing gastric bypass surgery was associated with resolution or improvement of diastolic hypertension in approximately 70% of cases. Resolution or improvement of hypertension occurred more often in patients with a lower postoperative body mass index.

Changes in eating behavior after horizontal gastroplasty and Roux-en-Y gastric bypass.

Postoperative changes in eight dietary variables were compared at 6-mo intervals over 24 mo in 53 horizontal-gastroplasty (HGP) and 51 Roux-en-Y gastric-bypass (RYGB) patients; the variables included 1) calorie intake; percent intake of 2) protein, 3) carbohydrate, and 4) fat; 5) sweets and high-calorie beverages (SWS) and 6) milk and ice cream (MIC) as percent of calories; and 7) high-calorie liquids (HCL) and 8) nonliquid sweets (NLS) as percentage of dietary sugar. Weight and calorie intake were significantly less after RYGB than after HGP after 6 mo (p less than or equal to 0.01). Protein intake was significantly increased at all intervals after RYGB and at 6 and 12 mo after HGP (p less than 0.05). After RYGB, intakes of SWS, MIC, and HCL were significantly decreased at all intervals (p less than 0.05). SWS and MIC consumption was also significantly less after RYGB than after HGP (p less than or equal to 0.05). Decreased SWS and MIC consumption in RYGB patients suggests that food-preference differences are partially responsible for the lower calorie intake and greater weight loss after RYGB than after HGP.

Follow-up study of risk factors in progressive supranuclear palsy.

The cause of progressive supranuclear palsy (PSP) is not known and has been little studied. The one previous controlled epidemiologic survey, performed at our center in 1986, found small-town experience and greater educational attainment as PSP risks, but, in retrospect, these results may have been produced by ascertainment bias. Since that time, several anecdotal reports have implicated heredity and various environmental exposures in the cause of some cases of PSP. To clarify the results of the previous study and to evaluate the more recently implicated candidate factors in a controlled fashion, we mailed a validated 69-item questionnaire to 91 personally examined patients with PSP and 104 unmatched controls with other neurologic conditions for which they had been referred to our tertiary neurologic center. We were able to match 75 subjects from each group by year of birth, sex, and race and subjected them to a separate matched-pair analysis. We allowed surrogates to supply any or all of the responses. Questions concerned hydrocarbon, pesticide, and herbicide exposure; urban/rural living; auto repair and other occupations; head trauma; educational attainment; maternal age; and family history of PSP, parkinsonism, dementia, and other neurologic conditions. A statistically significant finding was that patients with PSP were less likely to have completed at least 12 years of school (matched odds ratio = 0.35, 95% CI = 0.12-0.95, p = 0.022; unmatched odds ratio = 0.44, 95% CI = 0.21-0.89, p = 0.020). We hypothesize that this result may be a proxy for poor early-life nutrition or for occupational or residential exposure to an as-yet unsuspected toxin. Future studies should examine these potential risk factors in PSP.

Relationship between summertime ambient ozone levels and emergency department visits for asthma in central New Jersey.

The 5-year retrospective study of the association between temperature and emergency department (ED) visits for asthma with mean ambient ozone levels between 10:00 and 15:00 was conducted in central New Jersey during the summer months. An association was identified in each of the years (1986-1990). Between 8 and 34% of the total variance in ED visits for asthma was explained by the two environmental variables in the step-wise multiple regression analysis. ED visits occurred 28% more frequently when the mean ozone levels were > 0.06 ppm than when they were < 0.06 ppm. This result was statistically significant in a covariance analysis. An evaluation of the effects of ozone on asthmatics reported in the literature was completed to determine if, as proposed by Bates, the results from different types of studies were coherent among the health metrics. A consistency in the magnitude of reported effects and the time lag between exposure and response for four different health indices (symptom reports, decrements in expiratory flow, ED visits, and hospital admissions) was identified and indicates a coherence between ozone and respiratory response to ozone exposure. This supports a proposition that ozone adversely affects asthmatics at levels below the current U.S. standard.

Use of longitudinal analysis of peripheral blood counts to validate historical reconstructions of benzene exposure.

We studied over 17,000 peripheral blood counts, accumulated during hematologic surveillance from 1940 through 1975, from a cohort of 459 benzene-exposed workers. Linear regressions demonstrated significant decreases in white and red cell counts, as well as hemoglobin, for workers exposed during the 1940s, without persistent trends over the ensuing 25 years. Strongly positive correlations were observed between these blood count fluctuations and fluctuations in retrospective estimates of benzene exposures for these workers in the earlier period of surveillance (mean estimated exposure 1940 to 1948, 75 ppm), but not for later years, (mean estimated exposure 1948 to 1975, 15 to 20 ppm). These data suggest substantial limitations of hematologic examination of populations to detect abnormalities in populations currently exposed to benzene. The analysis also demonstrates a novel approach to the biological validation of exposure estimates based upon limited industrial hygiene and historical record data. The application of biologic monitoring data may be useful for assisting decisions in reconstruction of a previous exposure.

The dilemma of outcome assessment after operations for morbid obesity.

Outcome of 56 patients who underwent horizontal gastroplasty (HGP) and 126 who underwent Roux-en-Y gastric bypass (RYGB) was assessed at 18 months postoperatively according to three definitions of successful weight loss; also, outcome was evaluated in the context of amelioration of obesity-related medical problems. Outcome definitions included the following: I, loss of 25% or more of preoperative weight; II, loss of 50% or more of excess weight; III, loss to within 50% of ideal body weight. To evaluate the impact of preoperative weight on success rate, patients were divided into two weight groups: "morbidily" obese patients, who were 100 to 199 pounds overweight (n = 146), and "super"-obese patients who were 200 pounds or more overweight (n = 36). Weight loss was significantly greater with RYGB versus HGP by each of the three definitions of success. Medical problems either improved or resolved with weight loss in 95% of cases. There were statistically significant differences in success rate depending on outcome definition in both HGP and RYGB patients. Success rate ranged from zero in super-obese HGP patients by Definition III to 97% in super-obese RYGB patients by Definition I. Although super-obese patients lost more pounds than the lighter morbidly obese patients, a significantly lower number of super-obese patients lost within 50% of ideal weight. Super-obese patients must lose more weight to reduce their actuarial risk. These results show that the definition of successful outcome may significantly influence the overall success rate in a large series of bariatric surgical patients.

Accuracy and reproducibility of blood lead testing in commercial laboratories.

OBJECTIVE: To assess the proficiency of commercial laboratories in analyzing lead in clinical blood samples from subjects without overt lead exposure. DESIGN: We submitted masked duplicate blood lead specimens to 8 masked laboratories. Each laboratory received blood aliquots immediately following drawing (time 1) and 2 weeks later (time 2) from 7 human subjects and 3 bovine blood samples with known lead levels of 0.26, 0.57, and 0.79 micromol/L (5.4, 11.8, and 16.4 microg/dL). Of the 8 laboratories, 5 were commercial laboratories, 1 was a state laboratory, 1 was a research laboratory, and 1 was the Centers for Disease Control and Prevention reference laboratory. OUTCOME MEASURES: Correlation coefficients were calculated, and differences within and between laboratories were assessed by analysis of variance. RESULTS: Results were obtained for all specimens, with all the human subjects' overall mean lead levels being less than 0.48 micromol/L (<10 microg/dL). Each laboratory reported all human blood specimens appropriately, as having lead levels less than 0.48 micromol/L (<10 microg/dL) and within 0.14 micromol/L (3 microg/dL) of the overall mean for that subject. All internal reproducibilities were very high (range, 0.92-1.00) except for one (0.60), possibly lower because of 1 pair of specimens. Mean differences between blood samples analyzed at time 1 and time 2 ranged from -1.4 to 1.2, with only 2 laboratories having significant differences (P<.01). CONCLUSIONS: Overall, there was strong reproducibility within and among laboratories, with no overall time trend or interlaboratory or intralaboratory variance. The storage conditions did not seem to affect the aggregate results. The data suggest that through implementation of the Centers for Disease Control and Prevention/Wisconsin Blood Lead Proficiency Testing Program, the Centers for Disease Control and Prevention's Blood Lead Laboratory Reference System, and mandated federal and state proficiency programs, laboratories in this geographic region have improved their performance as compared with previous published studies and an unpublished study.

Prophylactic iron supplementation after Roux-en-Y gastric bypass: a prospective, double-blind, randomized study.

OBJECTIVE: To determine whether prophylactic oral iron supplements (320 mg twice daily) would protect women from iron deficiency and anemia after Roux-en-Y gastric bypass. DESIGN: Prospective, double-blind, randomized study in which 29 patients received oral iron and 27 patients received a placebo beginning 1 month after Roux-en-Y gastric bypass. SETTING: Tertiary care medical center. PATIENTS AND INTERVENTIONS: Complete blood cell count and serum levels of iron, total iron binding capacity, ferritin, vitamin B12, and folate were determined preoperatively and at 6-month intervals postoperatively in 56 menstruating women who had Roux-en-Y gastric bypass. MAIN OUTCOME MEASURE: Incidence of iron deficiency and other hematological abnormalities in each treatment group. RESULTS: Hemoglobin, hematocrit, and vitamin B12 levels were significantly decreased compared with preoperative values in both groups. Conversely, folate levels increased significantly over time in both groups. Oral iron consistently prevented development of iron deficiency in the iron group. Ferritin levels did not change significantly in the iron group. However, in placebo-treated patients, ferritin levels 2 years postoperatively were significantly decreased compared with preoperative levels. There was no difference in the incidence of anemia between the 2 groups. However, the incidence of microcytosis was substantially greater (P=.07) in placebo-treated than iron-treated patients. CONCLUSIONS: Prophylactic oral iron supplements successfully prevented iron deficiency in menstruating women after Roux-en-Y gastric bypass but did not consistently protect these women from developing anemia. On the basis of these results we now routinely recommend prophylactic iron supplements to menstruating women who have Roux-en-Y gastric bypass.

Lipid risk profile and weight stability after gastric restrictive operations for morbid obesity.

There are no longitudinal data that address weight loss stability and lipid levels in bariatric surgical patients. The goal of this study was to determine whether weight regain adversely affected reduction in lipid levels after gastric bariatric operations. Of 651 consecutive patients undergoing gastric restrictive surgery for morbid obesity, 227 (35%) had increased serum levels of total cholesterol (TC), triglycerides, or both preoperatively. High-density lipoprotein cholesterol (HDL-C) levels were subnormal (/=15% mean reduction in TC and a >/=50% mean reduction in triglycerides, both of which were significant in comparison with preoperative levels (P /=15% of their lost weight or lost less than 50% of excess weight (N = 37). Although mean excess weight loss and body mass index were significantly different between the two groups (P <0.0001) at 2 years, there was no difference in the lipid profile (TC/HDL) between the two groups at any interval through 5 years. These results show that abnormal lipid profiles can be permanently improved after gastric bariatric surgery and are not adversely affected by mediocre weight loss or regaining >/=15% of lost weight. DRY appears to be a superior operation for TC reduction in comparison with GP and RYGB.

Are vitamin B12 and folate deficiency clinically important after roux-en-Y gastric bypass?

Although iron, vitamin B12, and folate deficiency have been well documented after gastric bypass operations performed for morbid obesity, there is surprisingly little information on either the natural course or the treatment of these deficiencies in Roux-en-Y gastric bypass (RYGB) patients. During a 10-year period, a complete blood count and serum levels of iron, total iron-binding capacity, vitamin B12, and folate were obtained in 348 patients preoperatively and postoperatively at 6-month intervals for the first 2 years, then annually thereafter. The principal objectives of this study were to determine how readily patients who developed metabolic deficiencies after Roux-en-Y gastric bypass responded to postoperative supplements of the deficient micronutrient and to learn whether the risk of developing these deficiencies decreases over time. Hemoglobin and hematocrit levels were significantly decreased at all postoperative intervals in comparison to preoperative values. Moreover, at each successive interval through 5 years, hemoglobin and hematocrit were decreased significantly compared to the preceding interval. Folate levels were significantly increased compared to preoperative levels at all time intervals. Iron and vitamin B12 levels were lower than preoperative measurements and remained relatively stable postoperatively. Half of the low hemoglobin levels were not associated with iron deficiency. Taking multivitamin supplements resulted in a lower incidence of folate deficiency but did not prevent iron or vitamin B12 deficiency. Oral supplementation of iron and vitamin B12 corrected deficiencies in 43% and 81% of cases, respectively. Folate deficiency was almost always corrected with multivitamins alone. No patient had symptoms that could be attributed to either vitamin B12 or folate deficiency Conversely, many patients had symptoms of iron deficiency and anemia. Lack of symptoms of vitamin B12 and folate deficiency suggests that these deficiencies are not clinically important after RYGB. Conversely, iron deficiency and anemia are potentially serious problems after RYGB, particularly in younger women. Hence we recommend prophylactic oral iron supplements to premenopausal women who undergo RYGB.

Results of the second Clinical Skills Assessment Examination of the ECFMG.

To test the hypothesis that the clinical skills of many foreign medical graduates entering residencies in the United States are deficient, the Educational Commission for Foreign Medical Graduates (ECFMG) administered a second, more extensive pilot examination called the Clinical Skills Assessment Examination. The test was constructed after identifying those clinical skills considered to be suitable for testing in a large-scale examination conducted at multiple locations. The test was given to 635 foreign medical graduates (including 53 U.S. citizens) who had been certified by the ECFMG and to a reference sample of 123 graduates of U.S. medical schools. All of the graduates took the test prior to their first postgraduate year of training. The results did not differ significantly from those of a previous test. The clinical skills of 28% of the graduates of foreign medical schools who took the examination were found to be inadequate when compared with those of graduates of U.S. schools. The conclusion reached was that a clinical skills examination is feasible for inclusion in the ECFMG certification process.

The role of the coronoid process in elbow stability. A biomechanical analysis of axial loading.

BACKGROUND: The current treatment of coronoid process fractures of the ulna is based on the classification system of Regan and Morrey. We found no biomechanical studies that specifically addressed the role of the coronoid process in elbow stability. In the present investigation, the elbows of cadavera were tested before and after fracture of the coronoid process to assess the stabilizing contribution of the coronoid process under axial loading. METHODS: Six fresh-frozen cadaveric elbows were tested mechanically. All soft tissue surrounding the elbow, including the skin, was left intact. An axial load compressing the elbow joint was applied along the shaft of the forearm in the sagittal plane. A displacement of fifteen millimeters per minute was applied until a load of 100 newtons was attained. Each elbow was tested in 15, 30, 45, 60, 75, 90, 105, and 120 degrees of flexion. Next, less than 25 percent, 25 to 50 percent, or more than 50 percent of the coronoid process was fractured with an osteotome under radiographic guidance, and the testing was repeated. Each elbow served as its own control, and one elbow was used for two tests; therefore, a total of seven situations were investigated. The difference in displacements between the intact and osteotomized elbows was measured. RESULTS: There was no significant difference, at any flexion position, in posterior axial displacement between the intact elbows and the elbows in which 50 percent or less of the coronoid process was fractured (type I and type II) (p = 0.43). There were significant differences, across all flexion positions, in posterior axial displacement between the intact elbows and the elbows in which more than 50 percent of the coronoid process was fractured (type III) (p = 0.006). Specimens with a type-III fracture also showed a significant increase in displacement compared with specimens with a type-I or type-II fracture (p = 0.012). Specifically, from 60 to 105 degrees of flexion, a significant increase in posterior translation of up to 2.4 millimeters was found (p<0.05). CONCLUSIONS: In response to axial load, elbows with a fracture involving more than 50 percent of the coronoid process displace more readily than elbows with a fracture involving 50 percent or less of the coronoid process, especially when the elbow is flexed 60 degrees and beyond.

Arthroplasty of the metacarpophalangeal joints with use of silicone-rubber implants in patients who have rheumatoid arthritis. Long-term results.

The long-term results of 144 arthroplasties of the metacarpophalangeal joints, with use of silicone-rubber implants, were reviewed for twenty-seven patients (thirty-six hands) who had rheumatoid arthritis. The operations were all performed or supervised by the same surgeon. All patients had an arthroplasty of the metacarpophalangeal joint of all four fingers, and all had subjective and objective clinical evaluation and roentgenographic assessment. Relief of pain, the cosmetic appearance of the hand, the range of motion of the metacarpophalangeal and proximal interphalangeal joints, and the presence of residual deformity were evaluated. The average duration of follow-up was eight years and six months (range, five years to sixteen years and three months). Preoperatively, the mean active-extension deficit of the metacarpophalangeal joints ranged from 53 degrees (index finger, right hand) to 70 degrees (little finger, left hand) and the mean flexion ranged from 84 degrees (index finger, right hand) to 94 degrees (little finger, left hand). At the early follow-up evaluation (average, four months postoperatively; range, two to six months), the mean extension deficit had improved to a range of 7 degrees (little finger, right hand) to 19 degrees (index finger, left hand), and mean flexion ranged from 56 degrees (little finger, left hand) to 66 degrees (ring fingers). The range of motion had improved from a non-functional arc of flexion to a more functional arc of extension. At the time of the latest follow-up visit, the motion of the metacarpophalangeal joints had not deteriorated.(ABSTRACT TRUNCATED AT 250 WORDS)

Arthrography of the wrist. Assessment of the integrity of the ligaments in young asymptomatic adults.

Fifty-two asymptomatic adults who were between twenty and thirty-five years old had arthrography of the wrist with use of a single injection into the radiocarpal joint. The purpose of the study was to evaluate the integrity of the triangular fibrocartilage, the scapholunate ligament, and the lunotriquetral ligament. Contrast medium was injected under fluoroscopic guidance, and posteroanterior and lateral radiographs of the wrist were made after the subjects had performed exercises of the wrist. No patient who had a history of trauma to the wrist, pain in the wrist, or inflammatory arthritis was included in the study. All of the subjects had an examination of both upper extremities that included measurement of the active motion of the wrist with a goniometer, strength-testing with a Jamar dynamometer, ballottement and testing for impingement, and palpation for tenderness. Plain radiographs were evaluated, and the ulnar variance was recorded. The arthrograms revealed an abnormal communication of the contrast medium in fourteen wrists (27 per cent), and four of the fourteen had multiple areas of communication. The abnormal communication was through the triangular fibrocartilage alone in six wrists, the scapholunate ligament alone in two wrists, the lunotriquetral ligament alone in two wrists, and in more than one of these areas in four wrists. A positive arthrogram was associated with a greater positive ulnar variance. All of the subjects had symmetrical motion of the wrists and grip strength, and none of them had tenderness in the wrist. There were no complications related to the arthrography. Perforation of a ligament in the wrist is common in young asymptomatic adults.(ABSTRACT TRUNCATED AT 250 WORDS)

Physician medical direction and advanced life support in the United States.

OBJECTIVE: To determine the specialty training and responsibilities of urban U.S. emergency medical service (EMS) medical directors how these factors relate to the type of service involved (fire, hospital, private, municipal). METHODS: A single mailed survey of training officers--field supervisors of 211 urban advanced life support (ALS) services in the United States. The survey also requested information about medications carried, approved procedures. and who set these standards. Respondents also rated the EMS medical director's involvement in various activities (quality assurance, administrative, executive, run reviews, and in-service/education). RESULTS: Eighty-five percent (n = 179) of the forms were returned. with 165 (78%) usable. The physician EMS medical directors were primarily trained in emergency medicine (77%) and were paiid (75%) for EMS responsibilities. The number of medications carried and the number of approved procedures were not related to either the number of hours the physicians commit weekly to the EMS service or their degree of involvement in ALS activities. The physician EMS medical directors were most often involved in quality assurance and education and were less likely to devote time to executive or other administrative functions of ALS units, with the exception of fire-based EMS physician medical directors, who contributed significantly to executive and administrative functions (p < 0.05). Overall practice standards were established by the medical director (46%), the state department of health (24%), and local/regional health authorities (23%). CONCLUSIONS: EMS training officers believe that urban ALS medical directors in the United States primarily provide quality assurance and educational support. With the exception of fire-based EMS systems. physicians appear to have limited involvement in other EMS administrative and executive functions.

Comparison of isomolar vs hyperosmolar enteral diets in experimental ileus.

The diarrhea observed after infusing hypertonic enteral alimentation solutions may be due to the high osmolality. We compared Vivonex HN (810 mOsm) to Osmolite (300 mOsm) in two canine ileus models. After having bipolar electrodes implanted in the stomach, duodenum, jejunum, and colon, four dogs sequentially underwent operations to produce intestinal obstruction (SBO) or perforation/peritonitis (PER). The SBO was released and the perforation closed 24 hr later. GI myoelectric activity (MEA) was monitored during the first 4 postoperative days and again on the 10th day to determine steady-state MEA. Fasting MEA was recorded for 1 hr, followed by 1-hr recordings after intragastric cannula infusion of either Vivonex HN or Osmolite. There was no significant difference in MEA produced by Osmolite vs Vivonex at any recording site. The 24-hr postop gastric and small bowel MEA was significantly decreased (p less than 0.05) vs postoperative days 2 to 4 and 10 under both fasting and fed conditions. The ileus operations had no effect on colonic MEA. These data show that SBO and PER cause significant decreases in gastrointestinal MEA for 24 hr. There was no difference in MEA response of Osmolite vs Vivonex HN. These results suggest that infusion of hypertonic enteral alimentation solutions does not produce increases in GI myoelectric responsiveness vs isotonic solutions.

Body weight and adequacy of hemodialysis. Results of an ESRD Network Study.

As part of the Medical Case Review Study mandated by the US Health Care Financing Administration, the Trans-Atlantic Renal Council obtained urea kinetic data on 244 patients. When analyzed by body weight, the mean Kt/V urea for the 35 patients weighing more than 1 standard deviation over the mean (over 88.1 kg) was 0.943, compared with 1.106 for the remaining 209 patients (p = 0.007). The high body weight (HBW) patients were 54% more likely to have a Kt/V less than 1.0 than the remaining patients (68.6% of HBW patients versus 44.5% of control patients, p = 0.009). Two-way analysis of variance showed that the tendency to underdialyze HBW patients was present across facilities. Even with the availability of urea kinetic data, HBW patients tend to be less well dialyzed than those of lower body weight.

Gender concordance between family practice residents and diagnoses in an ambulatory setting.

BACKGROUND: Female physicians are more likely than male physicians to treat female patients. This study extends the scope of previous studies by scrutinizing gender concordance with specific diagnoses. METHODS: A total of 90,407 physician-patient encounters handled by 90 family practice residents from 1984-1993 in an ambulatory care setting were analyzed. In addition to genitourinary problems, the analysis included the 20 most frequently recorded diagnoses. RESULTS: Patients' encounters with residents differed between male and female residents. Female residents handled more encounters (P < .001) for vaginitis, prenatal care, menstrual disorders, menopausal symptoms, cervicitis, abnormal Pap smear, breast disease, breast lump, and general medical exam (female patient). Female residents handled a greater percentage (P < .001) of female patients within the 20 most frequent diagnoses. There was little difference with male patients. CONCLUSIONS: Gender concordance is suggested between male and female patients with specific diagnoses and their physicians. Educators must balance patient preferences and satisfaction with adequate exposure to the gamut of medical problems.

Use of on-line medical command to randomize patients in a prehospital research study.

OBJECTIVE: To describe the efficiency of using on-line medical command (OLMC) to conduct a prospective, randomized clinical trial addressing safety and patient enrollment. DESIGN, SETTING, AND PARTICIPANTS: Prospective design using OLMC to randomize adult asthmatics into one of three treatment groups. After verifying inclusion and exclusion criteria, OLMC physicians removed a covering label on study sheets and ordered the treatment specified underneath the label that had been assigned in a random sequence. RESULTS: A total of 204 patients were seen with dyspnea and wheezing during the three-month study. Of these, 68 (33%) were excluded from the study. Of the 136 (67%) patients who were eligible for study, 87 were enrolled (enrollment efficiency 64%), with 79 fully evaluable (evaluable efficiency 91%). The study safety was 100% because no enrolled patients met any exclusion criteria. CONCLUSIONS: The design was random and prospective, with patient entry blinded, using paramedics to enroll patients and OLMC physicians as gatekeepers, thus ensuring appropriate patient eligibility and study-arm assignment. Use of OLMC physicians to perform prospective randomized studies is safe and efficient, and results in a high yield of evaluable patients.