Lithium-induced nephrogenic diabetes insipidus in older people

PRESENTATION

We report two patients. The first is a 68-year-old woman who presented with a 2-day history of vomiting. She was hypernatraemic and her elevated serum sodium concentration did not improve initially, despite adequate fluid replacement. She subsequently developed polyuria and polydipsia. The second patient, a 77-year-old woman, presented with delirium and severe hypernatraemia after being treated for a chest infection 1 week earlier. Both patients were on long-term lithium treatment.

INVESTIGATION

In both the cases, a supervised water-deprivation test done after normalization of the blood biochemistry showed partial nephrogenic diabetes insipidus.

OUTCOME

Lithium was discontinued.

CONCLUSION

Older people on lithium-especially those requiring supportive care-are at risk of severe hypernatraemia after an acute illness or if their fluid intake is restricted.

An unusual femoral hernia

An elderly woman presented with a lump in the right groin, clinically suggestive of a femoral hernia, but surgical exploration revealed a cystic mass of poorly differentiated adenocarcinoma. Post mortem examination showed it to be a metastic deposit of carcinoma of the gall-bladder. Presentation of gall-bladder carcinoma as a femoral hernia has not been previously reported.

Measuring blood pressure in the elderly: does atrial fibrillation increase observer variability?

OBJECTIVE

To compare the interobserver and intraobserver variability of blood pressure measurements in geriatric patients in atrial fibrillation and in sinus rhythm.

DESIGN

Prospective assessment of blood pressure measurements carried out in random order in two groups of elderly patients by five doctors unaware of the aims of the study.

SETTING

Acute assessment wards for geriatric medicine, Cardiff Royal Infirmary.

PATIENTS

50 Elderly patients in sinus rhythm and 50 in atrial fibrillation.

MAIN OUTCOME MEASURES

Interobserver and intraobserver variability of blood pressure measurements in the two groups expressed as the coefficient of variability and compared by the Mann-Whitney U test.

RESULTS

Interobserver variability was significantly greater in the patients with atrial fibrillation for both systolic and diastolic pressures. Intraobserver variability was significantly greater in the atrial fibrillation group for diastolic pressures but the difference was not significant for systolic pressures. These differences were not related to pulse rate, age, or level of blood pressure.

CONCLUSIONS

The findings suggest that in the presence of atrial fibrillation physicians' interpretations of Korotkoff sounds are less uniform, which may have important clinical implications. Possibly a standardised methodology may overcome this problem.

Can old people on oral anticoagulants be safely managed as out-patients?

Of 62 patients (mean age 75, range 65-92 years) referred to an out-patient anticoagulant clinic specifically for those aged 65 years or more, treatment was considered unsafe in only one patient and was discontinued. Minor bleeding which did not require a significant change in management was recorded on 25 (7%) of 381 clinic visits and one major haemorrhage occurred requiring emergency hospital admission. Anticoagulation was maintained within the therapeutic range on 284 (75%) visits. The results confirm that with appropriate out-patient care and supervision, the risks of oral anticoagulant therapy in the elderly need be no greater than in younger patients.

Significance of single serum urate estimations in acutely hospitalized elderly patients

Clinical, pharmacological and biochemical correlates of hyperuricaemia were studied in 399 consecutive patients aged over 70 years admitted to hospital with acute medical illness. Hyperuricaemia was significantly related to renal impairment and to the use of diuretics, but to no other recognized associations of gout, including typical or atypical joint symptoms. 'Routine' measurement of serum uric acid alone or as a component of biochemical profiles in acute illness in the elderly appears unjustified, particularly since raised levels may encourage inappropriate use of urate-lowering therapy.

A combination of cranial and peripheral nerve palsies in infectious mononucleosis

A 44 year old woman presented with bilateral brachial neuritis and an isolated Bell's palsy. Subsequently she was found to have infectious mononucleosis. The association of cranial and brachial neuropathy has not previously been reported. Without any specific drug therapy she recovered completely within 5 months.