Question

Use your own words to explain why a typical form of epinephrine is applied with a swab locally to control bleeding during nasal surgery. Why is this route preferred and how does this drug work?

Answer 1

Answer. Epinephrine is also called adrenaline, is hormone released from the adrenal medulla of kidney. It is released in response to stress via sympathetic nervous system. It has both alpha and beta adrenergic stimulating characteristics. The epinephrine is a potent vasoconstrictor and this property is utilized clinically in various scenarios. The various concentration epinephrine are used such as 1:100000, 1:200000 in various forms IV, IM and SC, though most potent concentration is found to be 1:100,000. Nevertheless, IV route onset of action is faster followed by subcutaneous route that is 5-10 minutes. Oral route is not preferred because of rapid absorption by the digestive system.

             Topical application of adrenaline has vasoconstrictor effect on skin and mucous membrane. Though its vasoconstrictor effect on mucous membrane and vasodilator effect on skeletal muscle is puzzling when injected intravenously. Because of its vasoconstrictor effect it is used together with local anesthetic to prolong the anesthetic effect and delaying the systemic absorption via its vasoconstrictor effect thus reducing the potential cardiac side effect.

The minimal or minute nasal anatomy and limited accessibility and potential for hemorrage due to profuse vascularity of nasal mucosa necessitate the application of nasal swab containing epinephrine to achieve hemostatsis.

Since epinephrine is sympathomimetic and when injected may produce profound cardiac abnormality and hypotension. Though minimal/moderate infiltration may produce significant hemodynamic alterations with reduced blood pressure and mild increase in cardiac rate. However it is highly risky with epinephrine injected to cause heart myopathy and cardiac arrest.

The cotton pledget soaked with epinephrine have shown to cause profound vasoconstriction and reduced post-operative pain by compressing tiny blood vessels in nasal mucosa and achieving hemostasis. This is not possible to cause hemostasis without causing potent cardiac side effects in case of injectable epinephrine.