226: Physiological Rationale for the Use of Xanthines in Spinal Anesthesia

Introduction: As is known, spinal anesthesia is almost always accompanied by a fairly high autonomic sympathetic blockade, which leads to temporary systemic vasodilation and arterial hypotension. In addition, pharmacological denervation of the adrenal glands occurs with subsequent development of temporary suppression of glucocorticoid and mineralocorticoid function with the development of hypoglycemia, hypovolemia, and transient hyponatremia. As a rule, arterial hypotension due to sympathetic blockade during spinal anesthesia is usually corrected by continuous or microbolus administration of adrenomimetics. Manifestations of transient adrenal insufficiency are usually compensated by infusion of sodium-containing crystalloids, sometimes glucose-containing solutions. At the same time, there is a previously well-studied, widely used group of pharmaceuticals - stimulants of the respiratory, vasomotor centers, adrenal glands - methylxanthines. Methods: We studied the effects of 200 mg of subcutaneously administered caffeine on the severity of arterial hypotension, postspinal headache, hypoglycemia during spinal anesthesia for pain relief of cesarean section in 30 patients without significant pathology. The control group consisted of 30 women in labor who were administered only an adrenomimetic - phenylephrine and isotonic sodium chloride solution. Results: The frequency of intraoperative hypotension was 50% in the caffeine group and 95% in the control group, the frequency of hypoglycemia was 25% in the caffeine group and 75% in the control group. The frequency of phenylephrine use was significantly lower in the caffeine group. The incidence of postspinal headache in the first 24 hours after spinal anesthesia was also significantly lower in the caffeine group. Conclusions: Caffeine (and possibly other methylxanthines) may be considered a physiologically justified adrenal stimulant - a means of compensating for the temporary adrenal insufficiency caused by spinal anesthesia.