THE EFFECT OF NEBULISED MAGNESIUM SULPHATE ON THE INCIDENCE OF POST OPERATIVE SORE THROAT

PRINCIPAL INVESTIGATOR

Dr.Mallika Balakrishnan , Additional Professor, Department of Anaesthesiology

CO-INVESTIGATORS

Dr.Bhagyalakshmi Ramesh,Assistant Professor,Department of Anaesthesiology

 Dr.KumarB.G,Junior Resident , Department of Anaesthesiology

BACKGROUND OF THE STUDY

Intravenous magnesium sulphate is extensively and routinely used in anaesthetic as well as critical care for a wide range of conditions such as Tocolysis, Toxemia of pregnancy , Asthma, and Torsades de pointes{1} .The general incidence of sore throat after tracheal intubation for general anaesthesia varies from 6.6 to 90%{2}It also increases the duration of hospital stay{3} . It is known that NMDA (N-Methyl D-Aspartate)receptors play a role in nociception and inflammation {4,5}. Magnesium sulphate works as an antagonist of the NMDA receptor.{6}This particular study aims to use magnesium sulphate in the nebulized format at very low doses from that normally used in other conditions to study the effect it has in reducing the sensation of post operative sore throat

AIM OF THE STUDY

To evaluate the efficacy of pre operative magnesium sulphate nebulization in reducing the incidence of post operative sore throat following general anaesthesia

DESIGN OF THE STUDY

Routine data based study

STUDY PERIOD

2017-2018

STUDY POPULATION :

45 patients will be included in the study, and they will be nebulized with 3ml of 225mg isotonic magnesium sulphate for 15 mins pre op,5 minutes prior to induction.The results will be compared with an equal number of controls who are routinely nebulized with 3ml  saline for 15 mins , 5 mins prior to induction

SETTING OF THE STUDY

 DEPARTMENT OF ANAESTHESIOLOGY, REGIONAL CANCER CENTER, TRIVANDRUM

INCLUSION CRITERIA

Patients of either gender , aged 18-60, belonging to American Society of Anaesthesiologists (ASA) status 1 or 2 undergoing elective surgery of two hours or more duration requiring endotracheal intubation after acquiring consent stating the procedure

 EXCLUSION CRITERIA

Patients with neuromuscular disease

Allergy or hypersensitivity to drugs,

Undergoing neck surgeries

Unwilling patients

METHOD OF STUDY

 The subjects under study will undergo overnight fasting and premedication with oral alprazolam 0.5 mg and pantoprazole 40mg HS and DOS morning.

The study population will be nebulized with 3ml of 225mg isotonic magnesium sulphate for 15 minutes, 5 minutes prior to induction.

Nebulisation by the OT staff, briefed by the anaesthesiologists

Standard monitoring ,intravenous access will secured.

Anaesthesia will be induced with fentanyl 2 mcg/kg and propofol 2mg/kg. Tracheal intubation will be facilitated by vecuronium 0.1mg/kg

7mm ETT tube (PVC) in female patients and 8 mm ETT tube (PVC) in male patients will be the standard sizes chosen

 The ETT cuff will be inflated with air.

The cuff pressure will be checked just after intubation using handheld tracheal cuff pressure monitor and then every 30 minutes till the end of surgery and will be maintained at 20 cm of H2O.

 No nasogastric tube will be inserted.

Maintenance of Anesthesia will be with  IPPV with air : oxygen mixture with fio2 of 45% and  1.8% of sevoflurane and intermittent doses of vecuronium as required.

Reversal of neuromuscular blockade with neostigmine 0.05 mg/kg and glycopyrrolate 0.01 mg/kg.

Extubation will be after the standard extubation criteria were met, and the patients will be shifted to PACU.

CONTROL GROUP

The control group is taken as the group of patients who were nebulized with 3ml of NS for 15 mins pre op, 5 minutes prior to induction and data for post operative throat which was tabulated for all the patients nebulized with NS in the year 2016 shall be acquired for comparison process

DATA COLLECTION AND ANALYSIS

Presence of sore throat will be noted at rest and on swallowing immediately after extubation, and 2 h, 4 h, 10h and 24 h postoperatively

Drug-related side effects will be noted , if any. Data will be expressed as mean, and 95% confidence interval of mean.

For categorical data, frequency and percentage of distribution will be calculated and for comparison between groups,Chi square /fisher’s exact test will be used

         Fisher’s exact test; P < 0.05 will  be considered statistically significant.

For quantitative (continuous data) , mean , standard deviation and range  will be calculated .

 For comparison of quantitative data between groups , students t test  will be used

REFERENCE

PARENT STUDY.Yadav M, Chalumuru N, Gopinath R. Effect of magnesium sulfate nebulization on the incidence of postoperative sore throat. J AnaesthesiolClinPharmacol 2016;32:168-71

1.http://reference.medscape.com/drug/mgso4-magnesium-sulfate-344444

2.Sumathi PA, Shenoy T, Ambareesha M, Krishna HM. Controlled comparison between betamethasone gel and lidocaine jelly applied over tracheal tube to reduce postoperative sore throat, cough, and hoarseness of voice. Br J Anaesth 2008;100:215-8.

3.. Higgins PP, Chung F, Mezei G. Postoperative sore throat after ambulatory surgery. Br J Anaesth 2002;88:582-4.

4.Lin CY, Tsai PS, Hung YC, Huang CJ. L-type calcium channels are involved in mediating the anti-inflammatory effects of magnesium sulphate. Br J Anaesth 2010;104:44-51.

5. Zhu MM, Zhou QH, Zhu MH, Rong HB, Xu YM, Qian YN, et al. Effects of nebulized ketamine on allergen-induced airway hyperresponsiveness and inflammation in actively sensitized BrownNorway rats. J Inflamm (Lond) 2007;4:10

6.Turpin F, Dallérac G, Mothet JP. Electrophysiological analysis of the modulation of NMDAreceptors function by D-serine and glycine in the central nervous system. Methods MolBiol 2012;794:299-312.