Geriatric renal function: estimating glomerular filtration in an ambulatory elderly population.

In elderly individuals, serum creatinine may remain normal as glomerular filtration rate (gfr) declines. Therefore, the estimation of glomerular filtration utilizing mathematical models incorporates age as an important variable. In order to adjust drug dosages and diagnose renal disease earlier in the elderly, a variety of such simplified estimates of gfr have been applied. Unfortunately, no estimator is as accurate as the cumbersome gold standards (e.g. inulin or iothalamate clearance) and the reliability of each may vary with the particular clinical setting. The purpose of this study was to critically evaluate three commonly used estimators of gfr-i.e., creatinine clearance (CC), Cockroft-Gault (CG), and 100 over serum creatinine (100/SC)-comparing them to iothalamate clearance (IC) in a group of healthy ambulatory geriatric subjects (n = 41; ages 65-85). IC declined 1 ml/min per year of age in our sample. CC demonstrated a similar decline, a correlation of 0.83 with IC, and moderate error relative to IC of 17% at the mean (standard error [SE] = 12.3). In contrast, 100/SC correlated only 0.56 with IC, demonstrated a large positive bias (41 ml/min), and showed no age-related decline. An age correction to 100/SC similar to that utilized in the CG formula was clearly necessary. Despite the age and weight correction used in the CG formula, we found the estimates from it to be inaccurate (correlation = 0.5; SE = 23.8). A simpler age-corrected formula (Est. IC = 1/2 [100/SC] + 88-age) was derived and proved significantly superior to CG in our ambulatory geriatric sample, but still exhibited enough error (SE = 16.4) to question its clinical utility. It appears that serum creatinine based estimates of gfr in the elderly may not provide accurate results.

Using chart reviews to assess residents' performances of components of physical examinations: a pilot study.

PURPOSE: To evaluate chart review as a method of assessing residents' performances of physical examinations in an ambulatory care setting. METHOD: In 1992, nurse authors at the Affiliated Hospitals at Canton of the Northeastern Ohio Universities College of Medicine assessed whether 22 internal medicine residents performed ten components of the physical examination by interviewing patient volunteers immediately after the patients' examinations. A total of 89 patient interviewees were included in the analysis; these patients were all new outpatients who had been scheduled for initial visits to obtain complete histories and physical examinations. Charts for the same patients were then retrospectively reviewed. The residents and faculty were blinded to both the chart reviews and the interviews. Statistical methods used were Pearson correlational analysis and variance-component analysis. RESULTS: The interviews and chart reviews showed 81% agreement in component performance. Completeness of the physical examination (whether measured by chart review or interview) did not correlate with other standard methods of resident evaluation, and completeness did not show a significant association with characteristics of the residents and patients. Two of the 22 residents assessed were identified as having completeness scores so low as to be unsatisfactory. CONCLUSION: That residents were identified as failing to perform examination components suggests that chart reviews, especially when independently verified by patient interviews, may be a useful evaluation tool for identifying inadequate performance of components of the physical examination and may identify the need for remediation.

Eosinophils in urine revisited.

The finding of eosinophils in the urine has been suggested to be useful in establishing the diagnosis of acute interstitial nephritis (AIN). The diagnostic accuracy of this test has not yet been defined. It is the purpose of this study to define the specificity, sensitivity, and the predictive positive and negative values for the presence of eosinophils in the urine. One hundred forty-eight patients with pyuria were tested for the presence or absence of urinary eosinophils. In this group consecutively admitted to the hospital with WBC in the urine, 4% of patients had urinary eosinophilia of greater than 1 eosinophil per 100 cells. Since none of this group had the diagnosis of AIN, the false positive rate was 4% and the specificity was 96%. In a selected group of patients in which the diagnosis of AIN was suspected by a nephrology consultant, urinary eosinophils were found in 6 of 15 patients with a confirmed diagnosis of AIN but were also found in 10 of 36 patients with another renal diagnosis. The sensitivity for eosinophiluria was 40% and the specificity was 72% with a positive predictive value of only 38%. We conclude that eosinophiluria is not an accurate test for the diagnosis of AIN. The false positive and negative rates are too high to confirm an AIN diagnosis.

Ventricular tachycardia in acute myocardial infarction: the role of hypophosphatemia.

The relationship between serum concentration of certain electrolytes and the pathogenesis of ventricular arrhythmia in myocardial infarction has been the subject of frequent review. The role of hypophosphatemia in the pathogenesis of arrhythmia in patients with acute myocardial infarction has not been as well studied. In our study group of 325 consecutive patients admitted to the coronary care unit of a community hospital, 111 were confirmed to have had a myocardial infarction. Patients were continuously monitored for ventricular arrhythmia during the first 24 hours, and the electrocardiographic records were reviewed for documentation of arrhythmia. From an admission blood sample, measurement of electrolytes included serum phosphate, calcium, bicarbonate, potassium, and magnesium. Associations between ventricular tachycardia and serum electrolyte abnormalities including magnesium, potassium, phosphate, calcium, and bicarbonate were studied. Low phosphate (less than 2.6 mg/dL) was a significant predictor of ventricular tachycardia in the myocardial infarction group. In the entire group of 325 patients prior to the confirmation of myocardial infarction, both low bicarbonate and low phosphate were significant predictors of ventricular tachycardia during the first 24 hours of hospitalization. Although management of acidosis is considered early in the hospital course, phosphate replacement therapy is usually not as often considered. We recommend further study on the effectiveness of replacement therapy in hypophosphatemic patients with chest pain to reduce the risk of ventricular tachycardia.

Pneumococcal bacteremia in three community teaching hospitals from 1980 to 1989.

STUDY OBJECTIVE: To review the clinical and laboratory findings in a large number of patients with pneumococcal bacteremia in the 1980s and identify risk factors associated with increased mortality. DESIGN: Retrospective review of medical records identified by blood culture logbooks and ICD-9 codes. SETTING: Three community teaching hospitals affiliated with a medical school in northeastern Ohio. PATIENTS: 385 inpatients with pneumococcal bacteremia admitted between Jan 1, 1980 and Dec 31, 1989. MEASUREMENTS: Important clinical and laboratory information was abstracted from patients' medical records, compiled, computerized, and analyzed. MAIN RESULTS: The patients' mean age was 48 years. The overall mortality was 25 percent. The mortality increased with age, reaching 42 percent in patients over 65 years old. For these elderly patients, the mortality was higher (55 percent) for patients admitted from nursing homes than patients from the community (36 percent). Higher mortality was also associated with congestive heart failure (p = 0.001), alcoholism/cirrhosis (p = 0.02), diabetes mellitus (p = 0.05), and malignancy (p = 0.02). A platelet count less than 150,000/mm3, renal dysfunction (serum creatinine > 2 mg/dl), and the number of lobes involved were also associated with mortality. Patients receiving standard therapy (penicillin, ampicillin, erythromycin, or cephalosporins) had lower mortality. Of the previously specified risk factors for mortality, only age, whether standard therapy was administered, the number of lobes involved, and the serum creatinine level proved to be independent risk factors according to logistic regression. CONCLUSIONS: The overall mortality from pneumococcal bacteremia has not decreased during the past 40 years. Risk factors associated with increased mortality were identified. Prevention by immunization with polyvalent pneumococcal polysaccharide vaccine should be practiced more widely.

Dialysis leg cramps. Efficacy of quinine versus vitamin E.

A controlled randomized double-blind study was done to determine the frequency and severity of leg cramps in 40 patients on dialysis with a history of leg cramps. All patients entered a 2 month placebo washout and were randomized into a 2 month double-dummy phase of quinine 325 mg at bedtime versus vitamin E 400 IU at bedtime. Of the 29 patients completing the study, 16 received quinine and 13 vitamin E. During placebo washout, the vitamin E group had a mean of 10.4 leg cramps per month, and the quinine group had a mean of 10.9. The vitamin E and quinine groups had a 1 month reduction in leg cramps to 3.3 and 3.6, respectively (p < 0.0005 for both groups combined); this was sustained at 2 months. A severity of pain index showed a statistically significant decrease for both groups. The 95% confidence interval for the difference between the number of leg cramps after vitamin E versus quinine treatment (95% confidence interval, -3.8, +3.2) suggests similar efficacy. Quinine and vitamin E were effective treatments for leg cramps in these patients. Considering the potential toxicity of quinine, vitamin E is recommended as the initial treatment of choice for patients on dialysis with leg cramps.

Searching for a pattern: repeat suicide attempts.

1. Although there is a large population of unsuccessful suicide attempts and the same patients are often admitted repeatedly, little investigation has been done to understand this group. 2. Prescription drugs were almost always used in overdose attempts. There was no indication that physicians successfully intervened in preventing abuse of prescribed medication among patients with a history of overdose suicide attempt. 3. Most people choose a method for suicide and repeatedly use the same method (physical versus overdose). The majority of repeat attempts occurred among young people, and alcohol use was especially high when physical methods were used. Identification of these trends could lead to effective intervention.

Transluminal angioplasty in patients with bilateral renal artery stenosis or renal artery stenosis in a solitary functioning kidney.

Renal angioplasty in patients with bilateral renal artery stenosis or with renal artery stenosis in a solitary functioning kidney has been thought to be relatively contraindicated. We report the results of renal artery angioplasty in 18 patients, 10 with severe bilateral renal artery stenosis and eight with severe renal artery stenosis in a solitary kidney. Twenty-five (89%) of 28 angioplasties were successful, with a mean improvement of the degree of stenosis from 85% to 18% after angioplasty and a restoration of renal blood flow. A significant drop in mean blood pressure at admission of 187/101 mm Hg to 154/87 mm Hg at discharge, 152/86 mm Hg at 3-month, and 146/82 mm Hg at 1-year follow-up was seen. Because of the decrease in blood pressure, 11 of the patients decreased or stopped taking diuretics and 15 decreased or stopped taking antihypertensive medications. Although no significant change in renal function was found by measuring mean serum creatinine levels over time, no patient had an elevated serum creatinine level at follow-up, indicating preservation of renal function. One major complication, cholesterol embolization to the bowel, was seen. Our results suggest that angioplasty is an acceptable treatment of hypertension in patients with bilateral renal artery stenosis or renal artery stenosis in a single kidney.