ACQUIRED HEMOPHILIA IN OLDER PEOPLE: A POOR PROGNOSIS DESPITE INTENSIVE CARE

the start of the study, systemic blood pressure increased to 95/65 mm Hg; after 2 weeks of treatment, the patient was able to leave the bed and to stay in a seat and was found to be amenable to a rehabilitation program. Our results suggest that sildenafil could be effectively and safely used in very old patients with secondary pulmonary hypertension, allowing the daily dose of furosemide to be reduced and thereby making escalating doses of loop diuretics unnecessary. The phosphodiesterase 5 (PDE 5) pathway is highly represented in the lungs, and sildenafil, a selective PDE 5 inhibitor, by making more cyclic guanosine monophosphate available, is able to induce a selective pulmonary vasodilation, which preserves the ventilation:perfusion ratio, as the improvement of arterial blood gases in our patients and in previous series indicates. This finding is consistent with selective or prevalent vasodilation of ventilated lung units; nonselective pulmonary vasodilation would expose the patient to an imbalance between ventilation and perfusion, thus worsening the gas exchanges and, ultimately, PaO2, PaCO2, or both. Baroreflex sensitivity decreases with age in healthy subjects, and deconditioning secondary to chronic diseases could further contribute to worsening vascular reflexes, putting frail elderly people at special risk for sildenafilinduced hypotension. Nevertheless, in a patient with severe pulmonary hypertension and systemic hypotension, sildenafil could improve systemic blood pressure and contribute to making the patient amenable to a rehabilitation program. This favorable result suggests that even severe hypotension coexisting with pulmonary hypertension does not exclude a trial with sildenafil, because relieving the pulmonary vascular barrage could improve left ventricular filling and, subsequently, arterial pressure. Alternatively, it cannot be excluded that sildenafil relieved arterial hypotension by increasing PaO2 and thereby improving heart function. Indeed, findings in hypoxemic patients with chronic obstructive pulmonary disease show that hypoxia impairs left ventricular relaxation and indirectly could depress the systolic function. The present experience cannot guarantee that any older patients with pulmonary hypertension and systemic hypotension will benefit from sildenafil. The risk exists that, in occasional patients, lack of pulmonary vascular effect and retained systemic vascular effect worsen rather than improving health status. Accordingly, it seems safe to monitor vital parameters and SPP at least on the occasion of the first dose of sildenafil. With this precaution in practice, sildenafil may be a valuable tool in the management of severe secondary pulmonary hypertension even in the very old.