We present the anesthetic management without major complications of a patient with a giant ovarian tumor with a fluid volume of 83 l.
Slow aspiration of cystic tumor fluid before ovarian resection cannot be done when the tumor is entirely solid or if malignancy is suspected, because a puncture in such cases could cause dissemination of malignant cells. In our case, the tumor was cystic with no evidence of malignancy on tumor markers and thoracoabdominal CT, which allowed us to proceed with fluid aspiration as our initial step in tumor removal.
We selected general anesthesia during the fluid-extraction procedure. Because of the giant tumor size, there was a high risk of hemodynamic collapse and re-expansion pulmonary edema even after fluid extraction and these complications would have made emergency airway maintenance difficult. There have been reports of similar cases performed using epidural anesthesia (Miyawaki et al. 2000; Nishiyama & Hanaoka 1997) for the fluid-extraction procedure. However, we avoided epidural anesthesia in this case for the following reasons: 1) high risk of epidural hematoma formation because of dilatation of the epidural venous plexus; 2) potential technical difficulties due to increased internal epidural pressure; and 3) potential hemodynamic instability associated with administration of local anesthetics into the epidural space.
We intubated our patient using the Airway Scope in a semirecumbent position under conscious sedation because she was considered to have a fully dilated abdomen and the absence of spontaneous respirations would cause ventilatory failure. In addition, the semirecumbent position effectively prevented hypoxemia due to increased compression of the lungs as well as supine hypotensive syndrome. The Airway Scope is useful in a variety of positions (Komasawa et al. 2010) and, as in previous reports, (Suzuki et al. 2009) we were able to perform successful tracheal intubation using the Airway Scope in a semirecumbent position. We elected to maintain spontaneous respirations because controlled ventilation would have been difficult owing to elevated intra-abdominal pressure during tumor fluid extraction. To maintain spontaneous respiration, analgesia was performed using local anesthetic infiltration and no muscle relaxants were used. Maintaining spontaneous respiration with pressure-supported ventilation and PEEP prevented hypoxemia and hypercapnia. As the abdominal pressure decreased after tumor fluid extraction, controlled ventilation could be easily achieved.
We believed that gradual fluid extraction would effectively prevent re-expansion pulmonary edema. Re-expansion pulmonary edema is a non-cardiogenic pulmonary edema caused by rapid expansion of the lungs after long-term collapse and the risk factors include lung collapse over a period of 3 or more days, or evacuation volume of 2000 ml or more. The onset is rapid, usually within 1 h after re-expansion of the lung, (Sohara 2008) and there is no consensus with respect to an ideal extraction rate for preventing re-expansion pulmonary edema in a patient with a giant cystic ovarian tumor. In previous reports, extraction rates of 44.3 l in 2 h (22.2 l/h) (Nishiyama & Hanaoka 1997) or 11 l in 20 min (33 l/h) (Miyawaki et al. 2000) prevented re-expansion pulmonary edema. In our case, the drainage rate of 500 ml/min (30 l/h) did not cause re-expansion pulmonary edema. We believed that this rate was reasonable based on previous reports. Also, although the chest X-ray in our patient showed an elevation in the bilateral diaphragm, the CT images indicated no atelectasis, a result of anteroposterior and lateral expansion of the thoracic cavity. The absence of preoperative lung collapse was likely another factor preventing re-expansion pulmonary edema in this case.
The gradual removal of cystic tumor fluid, maintenance of spontaneous respiration during fluid extraction, and monitoring of CO, SVV and CVP provided stable hemodynamic management during surgery. Local anesthetic infiltration minimized the administration of opioids and allowed the patient to maintain spontaneous respiration. The rapid removal of fluid from a giant cystic ovarian tumor can lead to unexpected redistribution of blood and increasing intrapleural pressure by controlled ventilation decreases venous return. These procedures cause hypotension by preload reduction, and avoiding these procedures maintained stable hemodynamics in our patient. Monitoring of CO, SVV and CVP was useful to determine the appropriate dopamine dose and transfusion.
We report the anesthesia of a patient with a giant ovarian tumor with a tumor fluid volume of 83 l. Maintenance of spontaneous respiration and slow aspiration of the tumor fluid prevented respiratory and hemodynamic failure and resulted in safe anesthetic management during giant ovarian tumor resection.
