comparison of intranasal and intravenous dexmedetomidine infusion in providing induced hypotension in functional endoscopic sinus surgery(FESS)-A Randomised double blind trial

Functional endoscopic sinus surgery is a minimally invasive procedure and considered

to be the primary approach used today for the surgical treatment of chronic sinusitis and

sinonasal polyps that is commonly performed under controlled hypotensive anesthesia. In

FESS surgeries,due to excessive bleeding which leads to impaired visibility of the operative

field and various complications. So a dry operative field is necessary for a more definitive

removal of the polyp (lesion) ,so the vital structures less damaged and thereby tissue

infection is also minimized. Controlled hypotension is a technique used to limit

intraoperative blood loss and provide the best possible field for surgery.

Induced or Controlled hypotension is a technique in which the arterial blood pressure is

decreased in a predictable and deliberate manner. The intent of deliberate hypotension is to

reduce bleeding that facilitate surgery and to decrease the need for blood transfusion

The target of induced hypotension is (60-70mmhg), Hypotension is defined as MAP

<55mmHg.Several drugs have been used successfully to produce controlled hypotension IN

FESS during general anesthesia for example inhalational anesthetics, direct vasodilators

(sodium nitroprusside and nitroglycerin), beta adrenergic antagonists (propranolol 2 and

esmolol), alpha adrenergic agonists (clonidine and dexmedetomidine), calcium channel

blockers, prostaglandin E1 (alprostadil), adenosine[1] and l-receptors agonists

(remifentanil).

IV Dexmeditomedine infusion has been studied in various surgery in producing

controlled hypotension The newer α2-adrenergic agonist Dexmedetomidine was introduced

in the market in 1999 for sedating patients on mechanical ventilation those who are

admitted in intensive care units, Later it was approved by FDA for ICU

sedation.Dexmedetomidine is an α2-2 adrenergic receptor agonist with sedative, anxiolytic,

sympatholytic, and devoid of respiratory depression and analgesic effects best described as

opiod sparing,Dexmeditomedine is rapid in onset and short acting,though intravenous

dexmeditomedine infusion has been studied extensively in doses ranging from 0.4-

0.6mcg/kg in FESS surgery Previous studies have reported that intranasal DEX 1–

1.5mcg/kg produced significant sedation within 45–60 min and its elimination half-life was

114 min in healthy volunteers.

Though Intranasal DEXMED Dose range to 1 to 3mcg/kg in paediatrics has been

studied for premedicaton in paediatrics as,well as in adults including elderly in reducing

agitation,pain and haemodynamic stability,,its use in FESS surgery not being studied.hence

we would like to compare efficacy of intranasal dexmed versus intravenous dexmed

infusion in providing induced hypotension analgesic and bloodless surgical field in FESS

surgery