[Usefulness of human atrial natriuretic peptide in neurosurgical perioperative management]

Intensive hypotension is an important technique in neurosurgical perioperative management. However, it could decrease urine volume, and induce fluid retention resulting in cardiac failure. We evaluated the efficacy of human atrial natriuretic peptide (hANP) on diuresis in a hypotensive condition.

In 245 patients undergoing neurosurgical operations under general anesthesia in our hospital, 26 patients demonstrated a urine volume less than 50 ml/h at 1 hour after the skin incision, despite receiving a large volume of intravenous fluid. In these 26 patients, we administered hANP (0.05 microg/kg/min) continuously, and evaluated the effect of hANP on diuresis in a hypotensive condition.

After the administration of hANP, the urine volume increased significantly (p<0.01) from 28.7 to 229.4 (ml/h, mean). The heart rate increased from 66.6 to 71.7 (bpm, mean), whereas the systolic blood pressure decreased from 110.3 to 102.2 (mmHg, mean). The electrocardiogram did not change during the administration of hANP.

Despite the hypotensive condition, hANP showed a strong diuretic effect in our study. In neurosurgical perioperative management, administration of hANP can be a useful tool for a fluid balance in the patient.