Systolic pressure variation (Deltadown) can guide fluid therapy during pheochromocytoma surgery.

PURPOSE: To date, no monitoring has proved its usefulness for both interpretation and treatment of arterial hypotension following pheochromocytoma resection. In this prospective observational study, we measured the negative component (Deltadown) of the respiratory systolic pressure variation in order to assess its ability to guide fluid therapy in 13 patients undergoing pheochromocytoma surgery.

METHODS

The arterial pressure waveform was recorded via a 20-g radial artery catheter. Deltadown was measured during abdominal exploration (baseline), after fluid loading, before and following tumour resection, and during treatment of arterial hypotension.

RESULTS

At baseline, Deltadown ranged between 1 and 15 mmHg (median: 3 mmHg). Volume loading (500 mL colloid over 20 min) performed during abdominal exploration significantly reduced Deltadown (P = 0.001) and resulted in Deltadown values </= 2 mmHg in all 13 patients. The Deltadown measured immediately before resection was larger in patients who had arterial hypotension (systolic arterial pressure (SAP) < 90 mmHg) following tumour removal than in other patients [4 (1-10) vs 1 (0-3) mmHg; P = 0.04]. During hypotension, Deltadown was greater in patients where fluid replacement restored SAP than in patients where fluids were ineffective and vasopressors needed [Deltadown: 4 (3-9) vs 1 (1-2) mmHg; P = 0.03].

CONCLUSION

During pheochromocytoma surgery, a Deltadown </= 2 mmHg appears to indicate minimal intravascular volume depletion. Deltadown measurements could be used to guide fluid therapy for the prevention and treatment of arterial hypotension following pheochromocytoma removal.