Anesthetic aspects of laparoscopic adrenalectomy for pheochromocytoma

Undiagnosed catecholamine-secreting paraganglioma and coexisting carcinoid in a patient with MH susceptibility: an unusual anesthetic challenge

The management of a patient with two undiagnosed neuroendocrine tumors and possible malignant hyperthermia (MH) susceptibility poses a unique challenge to the anesthesiologist. We describe a total intravenous anesthetic including an alpha 2-agonist infusion combined with epidurally administered bupivacaine for intra- and postoperative pain management. Alpha 2-agonists may offer improved intraoperative hemodynamic management in patients with catecholamine-secreting tumors and reduce the total dose needed for intravenous anesthetics such as propofol. The latter mechanism may be useful to avert the risk of the propofol infusion syndrome occurring as a consequence of a high cumulative dose following its prolonged administration.

Arterial to end-tidal CO2 laparoscopic gradient reversal during pheochromocytoma resection

PURPOSE

We report the development of severe intraoperative hypercarbia and a pronounced arterial to end-tidal gradient reversal during laparoscopic pheochromocytoma resection. Although complex physiologic mechanisms may be responsible for this finding, anatomic alterations such as a direct communication between a capnoperitoneum and/or capnothorax and the airways resulting from prior pathology and the type of procedure should also be considered.

CLINICAL FEATURES

During anesthesia for laparoscopic pheochromocytoma removal we noticed an abrupt, extensive increase of the end-tidal CO(2) accompanied by a change of the capnographic CO(2) tracing and reversal of the normal arterial-to-end-tidal gradient. These changes consistently disappeared by intermittent deflation of the abdomen and at the end of surgery. A chest x-ray revealed a right-sided loculated pneumothorax with pleural thickening. Peritoneo-thoracic CO(2) tracking and pleural scaring with pulmonary adhesions resulting in a unidirectional communication between the pleural space and airways may best explain the chest x-ray and clinical findings.

CONCLUSION

Severe intraoperative hypercarbia and arterial to end-tidal CO(2) gradient reversal represents an intraoperative challenge. The possibility of a direct communication between the pleural space and the bronchial tree should be considered when other etiologies have been excluded. Simple maneuvers such as abdominal de- and re-inflation and analysis of the end-tidal capnographic tracing might aid in the differential diagnosis and management.