Neuromuscular blocking agents are administered to provide excellent intubating conditions to

minimize airway trauma. Muscle relaxants are broadly classified into depolarizing and non-

depolarizing muscle relaxants. In anaesthesiology, non-depolarizing neuromuscular blocking agents

are used routinely for endotracheal intubation. In our study atracurium a steroidal non- depolarizing

neuromuscular blocking agent will be used.

To provide rapid and profound intubating conditions various techniques like combination of

muscle relaxants, timing principle, high dose non-depolarizing neuromuscular blocker and priming

principle are used. Priming principle is a technique in which a small dose (10% to 30% of intubation

dose) of non-depolarizing neuromuscular blocking agent is administered 3-5 minutes prior to

administration of large intubating dose to produce relatively rapid and profound neuromuscular

receptors blockade to ensure adequate intubating conditions for endotracheal

intubation. This technique is preferred in rapid sequence intubation and in patients in whom non-

depolarizing muscle relaxant succinylcholine is contraindicated

Neuromuscular function is evaluated using qualitative and quantitative clinical tests. Qualitative

evaluation employs peripheral nerve stimulators (PNSs) and assesses visually or tactilely the

response of the stimulated muscle. A standard PNS can provide several patterns of nerve

stimulation such as train of four (TOF), double-burst (DBS), tetanic and post-tetanic count (PTC)

or degree of fade. The TOF stimulation pattern was introduced aiming at a tool providing clinically

reliable information through all phases of neuromuscular blockade with simple peripheral nerve

stimulator. Commonly stimulated nerve is ulnar nerve innervating adductor pollicis muscle.

The aim of our study is to evaluate the percentage of Neuromuscular receptors blocked, time taken

for zero twitch and intubating condition with and without priming with atracurium, in adult patients

undergoing elective surgery under general anaesthesia.In the literature, there are studies assessing

intubating conditions, hemodynamic stability, presence of post-operative sore throat & hoarseness

and, post-operative residual curarisation using TOF monitoring. However, there are not many

studies quantifying the percentage of neuromuscular receptors blocked with and without priming

principle using TOF monitor.

We hypothesize that 80% of the neuromuscular receptors will be blocked in 3 minutes following

priming with Injection Atracurium 0.05 mg/kg (1/10th of intubating dose).