Anesthetic challenges for pheochromocytoma surgery in pediatric patients

A case series

Abstract

Pheochromocytoma in children is an exceptionally uncommon cause of hypertension in this age group. These tumors pose a significant threat of adverse cardiovascular events during the perioperative phase. In this article, we describe three cases of pediatric pheochromocytoma to shed light on the difficulties associated with administering anesthesia to patients with this condition. The foundations for successful perioperative outcomes include preoperative blood pressure control, extensive intraoperative hemodynamic evaluation, and appropriate coordination with surgeons.

Introduction

Pheochromocytoma is a catecholamine-releasing tumor, very rare in the pediatric population.[¹] The occurrence of pediatric pheochromocytoma is 0.3 cases per million per year with a median age of 6 years to 14 years.[²] These tumors release catecholamines including epinephrine and norepinephrine. Its etiology could be genetic makeup or environmental factors. Pheochromocytoma is often associated with genetic conditions like Neurofibromatosis, Von Hippel-Lindau disease, and Multiple endocrine neoplasia (MEN) syndromes.[³] The most common clinical features are headache, hypertension, and tachycardia. A thorough evaluation is a pre-requisite to make a definite diagnosis of pheochromocytoma including serum and urine catecholamine levels, imaging, and genetic tests. In terms of urine markers, metanephrines give the most accurate biochemical indications of the presence of a pheochromocytoma. Additional biomarkers found in the urine that help diagnose pheochromocytoma include normetanephrine and vanillylmandelic acid (VMA).[⁴]

We present a case series of three cases of pediatric pheochromocytoma posted for laparoscopic excision during a period of 1 year at our institution. The most critical preoperative goals are thorough evaluation, cardiovascular stability, adequate control of symptoms, and normoglycemia. The important anesthetic implication of pheochromocytoma is sudden catecholamine release during intubation, carbon dioxide insufflation, tumor handling and surgical stimulation. Intraoperative goals are to maintain normovolemia, normoglycemia, blood pressure, and heart rate appropriate for age during and after tumor resection. Perioperative complications associated with pheochromocytoma are arrhythmia, hypertensive crisis during tumor handling, hypotension after vein ligation, and acute adrenal insufficiency, lasting 7 to 10 days post-surgery.

Case Series

All the cases were thoroughly evaluated in the preoperative period [Table 1]. Written informed consent and assent were taken from patients and their parents before the surgery. In the operation theatre, standard monitors were attached, including heart rate, non-invasive blood pressure, electrocardiography (ECG), and pulse-oximeter monitoring. In addition to American Society of Anesthesiology (ASA) standard monitors, continuous invasive blood pressure, central venous pressure, and urine output were also monitored [Figure 1]. After anesthesia induction, ultrasound-guided right-side internal jugular venous, and radial arterial lines were secured under aseptic precautions. In all cases, intravenous infusion of nitroglycerin, epinephrine, and norepinephrine were prepared to manage intraoperative hemodynamic fluctuations [Figure 2].

Table 1: Various parameters of patients scheduled for pheochromocytoma surgery

Figure 1: It shows the ASA standard monitoring that was done for the conduction of pheochromocytoma excision using a Drager monitor; it included heart rate, electrocardiograph (ECG), invasive blood pressure (IBP) with waveforms, SPO₂ (Oxygen saturation using pulse-oximeter) and temperature

Figure 2: It shows the multiple infusions prepared for the case, Injection Nitroglycerine (GTN), at a dose range of 10–200 μg/min according to blood pressure in case of sudden hypertension. GTN is a nitric oxide donor that causes both venous and arterial vasodilation. Injection Norepinephrine and injection Epinephrine both at a dose range of 0.05–0.5 μg/kg/min in case of hypotension

Case 1

A 15-year-old male diagnosed with pheochromocytoma was posted for laparoscopic pheochromocytoma excision. The patient had complaints of headache and palpitations for 2 months. He was diagnosed with hypertension. A thorough preoperative evaluation was done, and ECG showed normal sinus rhythm. The patient was taken inside the operation room; all ASA standard monitors were attached. Before induction, the left radial arterial line was secured after local infiltration. The premedication was administered with intravenous (IV) Fentanyl 2 mcg/kg and IV Midazolam 0.05 mg/kg. Preoxygenation was done with 100% oxygen for 3 minutes. Anesthesia induction was done with IV Propofol 2 mg/kg and muscle relaxation with IV rocuronium 0.3 mg/kg. Endotracheal intubation was done with cuffed Portex PVC 7 mm ID endotracheal tube (ET), fixed at 20 cm after bilateral chest auscultation. Maintenance of anesthesia was done with oxygen-air mixture 50:50 with Sevoflurane keeping the minimum alveolar concentration (MAC) value of 1 to 1.2. The laparoscopy was done without any adverse event, and the tumor was excised without any catecholamine release storm. Throughout the surgery, vitals remained stable except for transient hypotension after tumor excision [Figure 3]. The surgery continued for 5 hours, after which the patient was extubated, fulfilling extubating criteria, and complete neuromuscular reversal with IV glycopyrrolate 10 mcg/kg and IV Neostigmine 20 mcg/kg. He was transferred to the post-anesthesia care unit (PACU) with stable vitals without vasopressor support.

Figure 3: Shows the specimen, which includes the left side pheochromocytoma and the kidney. A schematic diagram shows the anatomic relation of various structures over the green sheet

Case 2

A 10-years-old male patient diagnosed with pheochromocytoma was posted for its laparoscopic excision. The patient complained of an episodic headache for 5 months, adversely affecting his studies. The patient underwent a thorough preoperative evaluation with ECG showing sinus tachycardia. After taking him inside the operation room, all ASA standard monitors were attached to the patient. Premedication was given as Midazolam 1 mg IV and IV Fentanyl 2 mcg/kg. Anesthesia was induced with IV propofol 2 mg/kg iv and muscle relaxation with IV rocuronium 0.3 mg/kg iv. Endotracheal intubation was done with cuffed 6.5 mm ID endotracheal tube (ET), fixed at 19 cm after bilateral chest auscultation. After 2 hours of surgery, a sudden rise in blood pressure and tachycardia was observed, for which the surgeons were notified, and IV esmolol 10 mg IV was given. The rest of the surgery went uneventful, and the patient was extubated after adequate neuromuscular reversal. The patient was shifted to PACU with stable vitals without any vasopressor support.

Case 3

A 13-years-old female had an incidental finding of pheochromocytoma and was posted for laparoscopic excision. The patient complained of pain in the abdomen for which she underwent computed tomography of the abdomen, and that time after a thorough work-up, she was diagnosed with pheochromocytoma. She had no signs and symptoms suggestive of pheochromocytoma. She was pre-operatively evaluated with vitals within normal limits appropriate for her age. Her heart rate was 110/min, blood pressure 130/90 mm Hg, and ECG showed sinus tachycardia. She was taken inside the operation room, and all ASA standard monitors were attached. Premedication was given as IV Midazolam 1 mg and IV Fentanyl 2 mcg/kg. The anesthesia was induced with IV propofol 2 mg/kg iv and muscle relaxation with IV rocuronium 0.3 mg/kg. Endotracheal intubation was done with cuffed ported 6.5 mm ID ET fixed at 19 cm. There were sudden variations observed with a crest in BP up to 220/130 mm Hg and trough value till 60/48 mm Hg. Titration of IV Noradrenaline infusion and IV Sodium nitroprusside was done according to the patient's blood pressure. After surgery, all the drug infusions were on minimum doses and tapered. The patient was shifted to PACU with stable vitals.

Discussion

This case series comprises of three cases diagnosed with pheochromocytoma. Here, anesthetic implications are about the disease itself along with the laparoscopy.[²] These tumors secrete excess catecholamine which needs to be optimized before the surgery to prevent hypertensive crisis and malignant arrhythmias.[¹] Catecholamine release increases during intubation, surgical stress, and tumor handling.[³] Intubation stress manifesting as tachycardia and hypertension can be well handled with esmolol boluses. After pneumoperitoneum creation and during tumor handling, there is always a risk of catecholamine release landing in the state of arrhythmia and sudden hypertension, for which infusion of IV sodium nitroprusside at a dose of 0.3–0.5 mcg/kg/min or IV Nitroglycerine at the dose of 10–150 mcg/min can be started and titrated according to the blood pressure value with respect to the baseline value, appropriate for age. Using magnesium sulfate (MgSO₄), Minami et al.[⁵] effectively managed the patient's hemodynamics during laparoscopic adrenalectomy for pheochromocytoma in a 5-year-old child. Because of its ability to inhibit catecholamine receptors, magnesium sulfate can reduce catecholamine secretion from the adrenal medulla and peripheral adrenergic nerve terminals. In addition, MgSO₄ causes vasodilation and has an antiarrhythmic action on the heart.

After adrenal vein ligation followed by pheochromocytoma excision, hypotension is the primary concern. Hypotension can be managed by commencing infusion of drugs like IV Noradrenaline at the dose of 0.01–0.1 mcg/kg/min.

In the present case series, all patients were stable without any vasoactive drug support at the end of surgery. Patients were followed up for 10 days after surgery for any untoward event.

Conclusion

Perioperative management of pheochromocytoma has always been challenging. Surgeon and anesthesiologist communication is vital in anticipating, preventing, and managing perioperative complications. Thus, we conclude that thorough preoperative evaluation, anticipation, preparedness, and prompt management are critical for the safe and smooth conduction of pheochromocytoma surgery.

Patients consent has been obtained for the publication of this case series.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.