Pheochromocytomas are tumors that originate from chromophobic tissue in the neuroectoderm and secrete mainly catecholamines. Some patients may suffer from severe cardiac, cerebral and renal damage due to long-term hypertension or sudden onset of severe hypertension, which may lead to life-threatening crisis.
Basic Information
The patient, a 42-year-old male, 170 cm in height and 62 kg in weight, was admitted to the hospital with the primary diagnosis of "left adrenal gland occupancy for more than 1 month on physical examination". Laparoscopic resection of the left adrenal mass was performed. There was no history of other medical problems.
Physical examination: blood pressure (BP) 106/79 mmHg (1 mmHg=0.133 Kpa), heart rate (HR) 75 times/min, respiratory rate (R) 15 times/min, no centripetal obesity, normal electrocardiogram, no significant abnormalities in blood routine, liver function, kidney function and other biochemical examination indexes, normal blood glucose and blood potassium.
Computerized tomography (CT) showed that the left adrenal gland was 2.5 cm × 2.1 cm × 2.2 cm, with neat margins and clear borders.
Enhanced CT showed that the enhanced scan showed heterogeneous enhancement, and lamellar hypodense areas were visible.
The patient had no palpitations, headache, profuse sweating, no history of hypertension, BP was sometimes even low, phenibut was not tolerated, and no regular preoperative treatment with alpha and beta receptor inhibitors or rehydration and volume expansion. During the patient's visit and communication with the surgeon, the surgeon considered this adrenal occupancy non-functional and did not perform routine preoperative preparation for pheochromocytoma.
Surgical procedure
The patient was admitted at 16:00 with BP 118/72 mmHg, HR 78 beats/min, oxygen saturation (SpO) 98%, SpO 100% after oxygenation, and BIS value 95. Invasive arterial pressure monitoring was established.
The induction of anesthesia was started at 16:15: imipramine 3 mg, sufentanil 20 μg, rocuronium 40 mg and propofol 150 mg were administered, and the patient experienced a transient BP drop to 98/50 mmHg and HR 93 beats/min after induction. BP rose rapidly to 155/98 mmHg, HR 98 times/min. 10 μg of sufentanil was given, BP decreased to 125/75 mmHg, and mechanical ventilation was performed after intubation.
The procedure was started at 16:30. The plasma target concentration was maintained at 3.0~3.5 μg/ml by continuous pumping of propofol, 2~4 ng/ml by remifentanil, and the BIS value was maintained at 50~60. Internal jugular venous puncture was performed and central venous pressure was measured at 6-7 cmHO (1 cmHO=0.098 Kpa).
Blood gas analysis was checked at 16:40 with the following results.
During laparoscopic exploration of the adrenal mass at 17:25, the patient's BP suddenly rose to 207/115 mmHg and HR to 142 beats/min. The possibility of surgical stimulation of catechol secretion was considered, but causes such as superficial anesthesia, carbon dioxide accumulation and bladder stimulation should be excluded.
Reason for exclusion
Deepening anesthesia, sufentanil 20 μg, rocuronium bromide 20 mg, and propofol 30 mg were given intravenously, and the pumping rate of propofol and remifentanil was increased, and the BIS value was gradually decreased from about 50 to 30. The urinary catheter was checked to be unclamped and the urine bag was not full. 500 ml of fluid had been infused from the beginning of anesthesia and the urine volume was about 200 ml. Then the operator stopped the surgical operation and BP gradually decreased to 170/100 mmHg. When the adrenal mass was peeled off again, the patient's BP suddenly rose to 211/112 mmHg and HR suddenly rose to 135 beats/min.
Phentolamine was given intravenously in sequential doses of 0.5 mg, 0.5 mg, and 1 mg, followed by esmolol in sequential doses of 5 mg, 5 mg, and 5 mg. BP decreased from 207/115 mmHg to 170/100 mmHg and HR decreased to 100 beats/min, but when the surgeon palpated the adrenal mass, BP rose again to 210/110 mmHg and HR rose to 136 beats/min.
The patient's BP dropped to 160/90 mmHg and HR dropped to 101 beats/min. During the separation of the mass, BP rose to a maximum of 250/130 mmHg and HR rose to a maximum of 140 beats/min. During the separation of the mass, BP rose to a maximum of 250/130 mmHg and HR was as fast as 140 beats/min.
Intraoperatively, hemolock blocked the mass vasculature, BP dropped abruptly from 180/110 mmHg to 71/42 mmHg, antihypertensive drugs were stopped, norepinephrine was pumped at a rate from 0.05 μg/(kg-min) to 0.25 μg/(kg-min), hydrocortisone 100 mg iv, reduced superficial anesthesia and accelerated fluid replacement to achieve arterial BP ≥ 90/ 60 mmHg and HR≤100 beats/min.
The operation lasted 4 h, with 2500 ml of fluid (1500 ml of crystalloid and 1000 ml of colloid), intraoperative bleeding of about 200 ml, and 450 ml of urine. With stable BP and HR, norepinephrine was gradually reduced and stopped, and the anesthetic pumping was stopped at the end of the operation. The patient's spontaneous breathing resumed, and the BIS value gradually rose above 85, and the tracheal tube was removed and sent to PACU.
Arterial blood gas analysis was repeated in the PACU with the following results.
The patient was clear and in general spirits in the PACU, complaining of a feeling of weakness. The patient was rehydrated with 500 ml of fluid and returned to the ward. The patient was discharged from the PACU: BP 96/75 mmHg, HR 94 beats/min, R 13 beats/min. The catecholamines and cortisol were rechecked 1 d after the operation without abnormalities. He was discharged 5 d after surgery.
The specimen was a pinkish gray nodule-like mass measuring 2.4 cm×1.9 cm×2.3 cm with smooth surface, intact envelope, grayish red and grayish white cut surface, tough, delicate, and containing dark red clot-like material.
Immunohistochemistry: CKpan (-), Vim (+), NSE (+), Cg-A (+), Syn (+), S-100 (-), Ki-67 (~1% +), P53 (-).
Pathological diagnosis: (left adrenal gland) pheochromocytoma with necrosis.
Possible reasons for atypical clinical symptoms of resting pheochromocytoma
1. The tumor itself has no secretory function or is hypofunctional.
2. Most of the norepinephrine secreted by the tumor is stored in the tumor and does not enter the bloodstream.
3. There are mechanisms within the tumor to metabolize the catecholamines themselves, and most of the catecholamines are metabolized in the tumor.
4. Some vasodilating substances secreted by the tumor, such as dopamine, vasoactive intestinal peptide, and calcitonin gene-related peptide, compete with renin for receptors, resulting in insignificant symptoms of high BP.
5. Hemorrhagic necrosis occurs inside the tumor and the function of catecholamine secretion is affected
Identification of resting pheochromocytoma
CT: Enhanced CT usually shows a unilateral round or oval adrenal mass, often with old hemorrhage, necrosis or cystic changes within the tumor, resulting in a heterogeneous density, with significant enhancement in the peripheral part and heterogeneous enhancement in the center.
Magnetic resonance imaging: The morphological presentation of adrenal pheochromocytoma is similar to that of CT, with characteristic signal changes, such as low signal on T1-weighted images and significant high signal on T2-weighted images.
Summary
Patients with resting pheochromocytoma have normal blood pressure, catecholamines and urinary vanilloid tonsils in the general state, but stressful conditions such as surgery or infection cause a sudden rise in blood pressure or it remains stable. The disease usually has no typical manifestation of paroxysmal hypertension, but fluctuations in blood pressure often occur during intraoperative exploration, and even hypertensive crisis can occur, which can easily cause accidents and may even produce serious complications if the preoperative preparation is not adequate. Therefore, preoperative diagnosis should be clarified as much as possible and important preoperative preparations should be made for resting pheochromocytoma. In addition, anesthesiologists should be vigilant and work closely with surgeons and do emergency treatment for sudden changes in patient's condition after tumor removal.
