The fall of the serum anion gap.

Using modern electrode technology (Beckman ASTRA analyzer), we evaluated the reference range for the anion gap (calculated as sodium minus chloride minus bicarbonate concentrations) in serum to determine whether the 8 to 16 mmol/L reference range in common use is still valid. After measurement of electrolytes in (1) serum from 29 healthy volunteers, (2) aqueous standards verified against National Bureau of Standards reference material, and (3) serum from 120 blood donors, we drew the following conclusions. (1) The reference range for the anion gap has shifted downward (to 3 to 11 mmol/L in one of our laboratories), primarily because of an upward shift in chloride values. (2) Using the ASTRA analyzer, a majority of normal individuals can be expected to have serum anion gaps of 6 mmol/L or less unless chloride calibration is deliberately altered. (3) If the anion gap is to remain an effective tool in diagnosing acid-base disorders, clinicians need to be aware that the traditional reference range may not be appropriate with new instrumentation.

Residents' perceptions of the effects of a practice plan on their training.

Residents were surveyed about the characteristics and quality of their education before and twice after a new practice plan for faculty members was implemented at a county medical center. The residents assessed the impact of the practice plan on their training programs. Compared with the ratings before the plan began (1984), the responses one and two years (1985 and 1986) after institution of the plan were significantly more positive on three of nine characteristics: quality of staff, quality of supervision, and heterogeneity of patients. Contrary to concerns expressed by faculty members and residents prior to the plan, the 1985 and 1986 residents did not identify significant decline in the level of their patient care responsibility and opportunities for independent decision-making. One-third of the residents in 1985 and 1986, however, commented (usually negatively) about increased time required for attending rounds due to involvement of faculty members in ward care and documentation activities. These results suggest that changes in faculty organization to increase patient care reimbursement are not necessarily incompatible with maintaining and even improving graduate education.

Thyroid function tests. Selective use for cost containment.

Clinicians often obtain a variety of thyroid function tests in patients suspected of having thyroid disease when only a few are necessary to adequately establish a diagnosis and do follow-up. For hyperthyroidism and hypothyroidism, measurement of serum T4 is the best screening test. The serum T3 resin uptake test should be added with women suspected of being hyperthyroid because of the changes produced by pregnancy or estrogen-containing contraceptives. Various imaging techniques, including RAI, ultrasound, CT, and MRI, are often used for differentiating benign or cystic thyroid nodules from malignant or solid ones. Each of the available techniques has a different cost, and each is most suitable for a particular disorder. Special tests (eg, TRH testing and measurement of serum TBG) should be added to the basic screening tests only for questionable cases to differentiate diagnostic possibilities or confirm an uncertain diagnosis.

Acid and gastrin levels following pyloric-preserving pancreaticoduodenectomy.

Acid and gastrin production after pyloric-preserving pancreaticoduodenectomy was evaluated in six patients. Five patients had low-normal basal and stimulated acid output; the sixth patient was achlorhydric. Fasting gastrin levels were less than 90 to 105 pg/mL (normal range) in five patients, three of whom had stimulated gastrin levels that remained below this range. Two patients had stimulated gastrin levels of 510 pg/mL and 205 pg/mL, respectively, within 15 minutes of eating; however, both levels returned to normal by 120 minutes' time. The sixth patient had mildly elevated fasting (105 pg/mL) and stimulated gastrin levels (160 to 200 pg/mL) throughout the test period. The results suggest that pyloric-preserving pancreaticoduodenectomy does not lead to either gastric hyperacidity or persistent hypergastrinemia.

Extended care in nursing homes: a program for a county teaching medical center.

A continuity care program for patients in nursing homes using internal medicine residents in training has been developed in a county teaching hospital. Resident physicians on a paid basis assume primary care responsibility for 1000 patients in 29 private community nursing homes. A faculty internist coordinates the activities of the residents and monitors patient care through an extended care office in the county hospital. The program has produced a significant upgrading of the continuity and quality of care of patients in these nursing homes as well as providing medical residents with geriatric and nursing home experience. The increased sensitivity and concern for the needs of nursing home patients developed by the medical residents seems to continue after they complete their training.

The do-not-resuscitate order in a teaching hospital: considerations and a suggested policy.

We present a policy for implementing the do-not resuscitate orders by medical residents in a teaching hospital, and discuss decision making, legal and ethical considerations, the primary physician's responsibility, and record documentation. THe establishment of a policy and procedure for implementing do-not-resuscitate orders resulted in greater consideration of patient and family rights and improved communication and sensitivity in dealing with those concerned with the patient's medical care and welfare.

Elevations of thyroid-stimulating hormone during acute nonthyroidal illness.

To determine whether the incidence of unrecognized thyroid disorders is high enough to warrant screening, we studied a group of 95 elderly hospitalized women with the use of clinical examinations, along with thyroid function tests. We found that 13 (13.7%) of the 95 women had elevated serum thyroid-stimulating hormone (TSH) levels and mean serum thyroxine (T4) levels, and their free T4 indexes and triiodothyronine levels (measured by radioimmunoassay) were lower than the levels in the normal control group. In four (4.2%) of the 95 patients, the elevation of TSH levels was transient. In two patients (2.1%), the elevation of TSH levels was caused by underlying hypothyroidism. The results of thyroid function tests, including serum TSH, obtained during acute nonthyroidal illness should be interpreted cautiously, and screening for thyroid disorders among elderly patients with acute illnesses is not warranted. While primary hypothyroidism may be regularly associated with an elevated TSH level, an elevated TSH level may be the result of an acute illness and not associated with clinical hypothyroidism.

Changing values for the normal thyroid radioactive iodine uptake test.

The normal range for thyroid radioactive iodine (RAI) uptake values in the Minneapolis area has shifted twice in the past 20 years. The mean 24-hour thyroid RAI uptake value in 29 normal subjects was 20.5% +/- 6.1% (SD) in 1975, whereas only four years previously it was found to be 11.5% +/- 4.4% (SD) in 51 normal subjects. In a previously published study, the mean thyroid RAI uptake value in normal subjects in this area was 25% +/- 8% (SD) in 1957. The iodine content of commercially baked white bread currently available in this area was found to average only 26 microgram per single slice of bread; the change in the mean 24-hour thyroid RAI uptake value that we observed between 1971 and 1975 is most likely due to a marked reduction in this source of dietary iodine.

Leydig-cell tumor of the testis with gynecomastia and elevated estrogen levels.

A normally-virilized 24-year-old white man who had gynecomastia was found to have a Leydig-cell tumor of the testis, without demonstrable metastases. Hormonal evaluation revealed negative serum and urine tests for human chorionic gonadotropin, and normal steroid excretion. Prior to orchiectomy, serum estradiol was elevated and serum testosterone depressed; postoperatively these values reverted to normal. Attempts to quantitative the estradiol content of the tumor failed to show a significant increase over normal testicular tissue, however. Histologically, the tumor showed classic Reinke crystalloids, the nature of which remains undefined. Electron-microscopic studies showed these crystals to have a regular hexagonal pattern.

Are research subjects really informed?

To determine how adequately patients who participate as subjects for clinical investigation understand their commitment, 50 patients admitted to the Clinical Research Center of the University of Washington were interviewed. Their responses were compared with the detailed statements in the consent forms for the 23 specific protocols under which they were being studied. In spite of careful controls in accord with guidelines of a review committee, only half the patients were able to describe accurately their expectations of the studies to which they had given signed consent.