Early recognition of myxedematous respiratory failure in the elderly.

OBJECTIVE

To report the clinical characteristics of myxedematous respiratory failure in the elderly and to facilitate early recognition of hypothyroidism in critically ill old patients.

METHODS

Clinical characteristics of our reported 4 patients and that of 17 patients with myxedematous respiratory failure reported previously were reviewed. Demographic information, vital signs, basic laboratory studies, and blood gas analysis were compared.

RESULTS

All 4 patients were older than 60 years and were hypoxic and hypercarbic upon presentation. All were found to have either anemia or marked electrolyte abnormalities and markedly elevated levels of thyroid-stimulating hormone once these levels were evaluated. Three of the 4 patients presented with profound lethargy and/or constipation, slowed intellectual ability, and dry skin.

CONCLUSIONS

Early recognition of hypothyroidism in elderly patients with myxedematous respiratory failure is crucial to prognosis. Whereas hypothermia, myxedema, and a history of thyroid disease mandate the thyroid function tests in patients with type 2 respiratory failure, the following 5 elements also warrant the thyroid function tests: bradycardia, anemia, hyponatremia, pleural or pericardial effusion, and a history of weight gain. Where mechanical ventilation has been applied, patients with difficult weaning from ventilator support should also be evaluated and screened for hypothyroidism.