comparative efficacy of nebulized ketamine, betamethasone, and lignocaine for mitigating postoperative sore throat, cough, and hoarseness of voice in elective surgery patients under general anaesthesia - a double blind randomized controlled trial

Postoperative sore throat (POST) is a common occurrence following general anaesthesia with endotracheal intubation although clinicians often regard it as a minor complication. The incidence of POST is estimated to be 21%–65% in different studies. POST although a self-limiting complication following general anaesthesia with endotracheal intubation, it continues to be an important concern for surgical patients. As perioperative physicians, we are entrusted with the deeds of decreasing the sufferings of surgical patients. When reviewing the literature for the prevention of POST, some non-pharmacological and pharmacological interventions have been tried with varying success rates. Nebulization is inexpensive, quick, convenient, and easy to administer also, which made this, the route of choice. In our study, we compared the effectiveness of ketamine and magnesium sulphate nebulization on POST .

The following factors influences the incidence of post-operative sore throat, which includes Experience of anaesthetist, adequate relaxation of the patient, careful insertion technique, soft suction catheters, smaller tracheal tubes, minimal cuff-tracheal contact area, monitoring and adjustment of intracuff pressure and avoidance of local anaesthetic /steroid lubricants. Various methods to alleviate postoperative sore throat has been reported in the literature. There are variable causes that can aggravate sore throat such as patient related factors, type of anaesthesia and type of surgery. Steroids are commonly used intraoperatively to reduce airway oedema and inflammation. Ketamine gargling has been used for sore throat but due to risk of aspiration, palatability limits its usage. Lignocaine jelly applied over tracheal tube cuff may reduce sore throat but because of inaccuracy of instilled drug and short duration of action some additional management has to follow for postoperative sore throat. Nebulization of lignocaine and ketamine prior to general anaesthesia confers good tube tolerability to patient as entire air passages is anaesthetized and attenuates sore throat after extubation

Ketamine has pharmacological properties such as analgesia, anaesthesia, and sympathetic action. Some studies have been done which show that ketamine decreases tumour necrosis factor-alpha production in a lipopolysaccharide-induced rat model of sepsis, and it demonstrates a protective mechanism in lung injury by decreasing the expression of inducible nitric oxide synthase and by its anti-inflammatory properties. Studies have suggested its role in endotoxin-induced tissue injury. It has been observed that local use of this drug through the nasal, oral, and rectal routes is both effective and plausible in ant nociception and anti-inflammatory cascade. Local anaesthetic drugs act by producing a reversible block to the transmission of peripheral nerve impulses. Lignocaine is used commonly for infiltration in concentrations of 0.5%–1.0% and for peripheral nerve blocks if an intermediate duration is required. Lidocaine 2%–4% is used by many anaesthetists as a topical solution for anaesthesia of the upper airway before awake intubation.