Pediatric emergency medicine trisk 1887 1887
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with normal saline is the major and, usually, the only measure needed to lower the
potassium. In the presence of arrhythmias, IV 10% calcium gluconate 1 mL/kg can be given
for its membrane-stabilizing properties. Therapy with glucose and insulin is contraindicated
because of the danger of precipitating hypoglycemia.
If hypoglycemia is found at the time of presentation, it should be treated acutely by the
administration of dextrose (0.25 g/kg) intravenously and by the subsequent inclusion of 10%
dextrose in the infusate.
Acidosis generally does not require specific treatment; however, the low serum bicarbonate
may take days to fully correct. Bicarbonate therapy is reserved for patients with both severe
acidosis (pH <6.9) and secondary hemodynamic compromise that is unresponsive to
inotropic agents.
Clinical Indications for Discharge or Admission
Hemodynamic instability, inability to tolerate oral medications or maintain hydration,
significant electrolyte or acid/base abnormalities, and refractory hypoglycemia are indications
for admission.
PHEOCHROMOCYTOMA
Goal of Treatment
To recognize the presentation of pheochromocytoma and to control hypertension.
CLINICAL PEARLS AND PITFALLS
Pheochromocytoma presents with episodic headache, palpitations, sweating; but
also nervousness, tremulousness, fatigue, chest/abdominal pain, and flushing.
Associated hypertension can be paroxysmal; alpha blockade is antihypertensive of
choice, pure beta blockade as a treatment for hypertension should be avoided as it
can precipitate severe hypertension.
Current Evidence
Pheochromocytomas are functional tumors that arise in chromaffin tissues. In most children,
these tumors are in the adrenal medulla, but they may be found in aberrant tissue along the
sympathetic chain. Less than 5% of all pheochromocytomas occur in children. They are twice
as common in males as in females, with the incidence of malignancy estimated to be 2% to
4%. Most information on pheochromocytoma is derived from adult studies, especially
regarding signs and symptoms. Few detailed studies are available on children.
Catecholamines are low–molecular-weight substances produced in the CNS, the
sympathetic nerves, the adrenal medulla, and the extra-adrenal chromaffin cells.
Catecholamines affect metabolic processes in most tissues of the body and have many effects,
including accelerated heart rate, increased myocardial contraction, and changes in peripheral
vascular resistance. Excessive production of catecholamines by a pheochromocytoma results
in intensification of the normal physiologic effects.
