Effect of priming technique and single intubating dose technique on rapid sequence intubation with rocuronium using train of four monitoring

Abstract

Aim: Rocuronium bromide has fastest onset time among non-depolarizing muscle relaxants; hence a safe alternative for RSI when the priming principle is used. The primary aim of this study was to compare the intubating conditions with priming technique and single intubating dose technique with rocuronium and to assess the onset time of rocuronium using Train of Four (TOF) monitoring. Materials and Methods: We conducted a randomized, prospective study in 60 patients of ASA I and II in age group of 20-50 years posted for surgeries under general anesthesia and divided into two groups of 30 each. In Group I priming was done with 1 ml of normal saline and Intubating dose of rocuronium 0.6mg/kg was given. In group II priming was done with 1/10 th i.e 0.06 mg/kg (1ml) of the total intubating dose followed by remaining dose of 0.54 mg/kg. In both the groups intubating doses of rocuronium were diluted to 10 ml of normal saline. TOF stimuli was used to assess the time of onset of intubation and Cooper scoring system was used to compare the intubating conditions. Results: Patients intubated in the priming group showed a faster onset time (61. 97 sec) than single intubating dose group (114.57) with successful intubation in both the groups. Excellent intubating conditions were seen in 97% patients and good intubating conditions in 3% patients of both the groups. Conclusion: Both priming technique and single intubating dose technique produces excellent intubating condition in majority (97%) of the patients with priming technique showing rapid onset time compared to single intubating dose technique. Introduction Rapid sequence intubation (RSI) technique is of utmost significance in patients vulnerable to aspiration such as full stomach, intestinal obstruction and general anaesthesia for emergency or elective caesarean section. The risks involved in RSI are failure to ventilate, heart rate changes, blood pressure variations and airway trauma. To avoid such undesirable side effects a modification of standard RSI technique has come up that includes preoxygenation, induction, cricoid pressure and gentle positive pressure ventilation. Modified RSI allows anaesthetist to confirm the ability to ventilate and to decide for awake intubation if ventilation failure occurs. Succinylcholine (Sch), a depolarising muscle relaxant was the drug of choice for RSI. 1 It produces profound muscle relaxation but has many undesirable side effects 2-4 that are related to the depolarising action of Sch. Hence nondepolarising muscle relaxants (NDMR) and newer techniques have evolved for rapid and smooth induction. But onset of action of NDMR is slow. So different approaches like increasing the single intubating dose of NDMR, combination of relaxants, priming dose, increased concentration of inhalational and intravenous agents are in use to potentiate neuromuscular blockade. 4 One such technique is timing technique where a single bolus dose of muscle relaxant is administered and the period from induction to complete muscle relaxation is noted. Rocuronium bromide has the fastest onse time among non depolarisers. When used with priming technique, it can be considered as an alternative to succinylcholine. In priming