Perianaesthetic management of patients with endocrine disease

[Anaesthesia for endocrine tumor removal]

Endocrine tumors could be defined by their ability to produce structural proteins or hormones common to nervous and endocrine cells. They might induce physiological transforms or outcome adverse events which should be well known in order to prevent or treat them early. The goal of this review was to describe these changes, to describe preoperative assessment, and to discuss intraoperative monitoring and drugs choice based on the literature from the last 30 years. As an example, it should be noticed that: (1) preoperative blood pressure control is essential to prepare phaeochromocytoma for surgery. It should be followed during anaesthesia by intensive fluid load, reversible anaesthetic drugs and rational cardiovascular medications use (as for example remifentanil, sevoflurane, calcium channel blockers and esmolol), and after surgery by narrow clinical and biological monitoring; (2) after medullar thyroid cancer, main adverse events include cervical compressive haematoma and recurrent laryngeal nerve injury as for any thyroid surgery; (3) during pituitary surgery, air embolism might be expected, whereas water dysregulation (diabetes insipidus), corticotroph insufficiency, cerebrospinal fluid (CSF) leak might occur postoperatively. In acromegaly, difficult endotracheal intubation is possible whereas severe Cushing's syndrome may be complicated with hypertensive cardiac failure, infections, thrombosis, delayed cicatrisation; (4) somatostatine analogs are a keystone in carcinoid tumors preoperative and anaesthetic management.

Anesthetic considerations in the multiple endocrine neoplasia syndromes

PURPOSE OF REVIEW

The multiple endocrine neoplasia (MEN) syndromes present a diverse array of challenges to the anesthesiologist. The tumors and their effects are often underdiagnosed and potentially discovered only when the patient is undergoing surgery for either a component of one of the syndromes or another procedure altogether. This can present the anesthesiologist with a life-threatening situation in the operating room. A thorough understanding of the syndromes, as well as management strategies, will enable the anesthesiologist to handle these patients.

RECENT FINDINGS

Advances in the pharmacologic armamentarium available to physicians have enabled patients with MEN, particularly those with the carcinoid syndrome or pheochromocytoma, to undergo surgery safely, with minimal morbidity and mortality.

SUMMARY

Awareness of the components of the MEN syndromes, as well as careful preoperative preparation, paves the way for a smooth anesthetic and postoperative course in these patients.

Uneventful spinal anesthesia for a patient with carcinoid syndrome managed with long-acting octreotide

PURPOSE

To present a case of spinal anesthesia in a patient suffering from carcinoid syndrome undergoing an inguinal hernia repair. In the past, regional anesthesia was considered unacceptable in these patients because of the possibility of intraoperative hypotension, hypertension, or bronchospasm. Recently, however, the preoperative use of octreotide, the synthetic analogue of the naturally occurring hormone somastatin, has been found to prevent these complications. Nevertheless, it remains unclear whether the use of this drug in patients with carcinoid syndrome allows the possibility of regional anesthesia.

CLINICAL FINDINGS

We report the uneventful use of spinal anesthesia in a patient suffering from carcinoid syndrome treated with long-acting octreotide. With careful attention to volume status of the patient and low volume of local anesthetics (10 mg hyperbaric bupivacaine 0.5%) supplemented with intrathecal narcotics (fentanyl 20 micro g), we were able to prevent any episodes of intraoperative hypotension in this patient. Octreotide was available in the operating theatre in case of an emergency. One of the original aspects of this case report is that the patient received long-acting octreotide (once a month administration) instead of the usual daily dose. In addition this is one of the few reports of spinal anesthesia administered to a patient with carcinoid syndrome.

CONCLUSION

Preoperative octreotide may result in more favourable conditions for regional anesthesia in patients with carcinoid syndrome. However, further studies will be required to confirm the favourable outcome observed in this patient.

Acute respiratory alkalosis associated with low minute ventilation in a patient with severe hypothyroidism

PURPOSE

Patients with severe hypothyroidism present unique challenges to anesthesiologists and demonstrate much increased perioperative risks. Overall, they display increased sensitivity to anesthetics, higher incidence of perioperative cardiovascular morbidity, increased risks for postoperative ventilatory failure and other physiological derangements. The previously described physiological basis for the increased incidence of postoperative ventilatory failure in hypothyroid patients includes decreased central and peripheral ventilatory responses to hypercarbia and hypoxia, muscle weakness, depressed central respiratory drive, and resultant alveolar hypoventilation. These ventilatory failures are associated most frequently with severe hypoxia and carbon dioxide (CO2) retention. The purpose of this clinical report is to discuss an interesting and unique anesthetic presentation of a patient with severe hypothyroidism.

CLINICAL FEATURES

We describe an unique presentation of ventilatory failure in a 58 yr old man with severe hypothyroidism. He had exceedingly low perioperative respiratory rate (3-4 bpm) and minute ventilation volume, and at the same time developed primary acute respiratory alkalosis and associated hypocarbia (P(ET)CO2 approximately 320-22 mmHg).

CONCLUSION

Our patient's ventilatory failure was based on unacceptably low minute ventilation and respiratory rate that was unable to sustain adequate oxygenation. His profoundly lowered basal metabolic rate and decreased CO2 production, resulting probably from severe hypothyroidism, may have resulted in development of acute respiratory alkalosis in spite of concurrently diminished minute ventilation.