Role of Magnesium Sulphate on Postoperative Delirium in Oncological surgeries- Protocol for a Randomized Controlled trial

• Background- Post Operative Delirium(POD) belongs to a wide spectrum of Post-operative Cognitive dysfunction(POCD) occurring after major surgeries. It adds to the morbidity and mortality of the patient as well as increases the financial burden. It has various risks and predisposing factors, which can be an interplay of factors from the pre-operative to post-operative period. The elderly age group is one non-modifiable predisposing factor. Various pharmacological and non-pharmacological methods have been tried to decrease the incidence. Magnesium sulphate is a drug that has multiple uses, but its role in the prevention of delirium is not yet known. We aim to find its role in decreasing postoperative delirium in elderly patients. • Methods : Consenting elderly patients, with no neurocognitive decline of ASA II to III physical status, posted for oncological surgeries under general anesthesia of more than equal to 2 hours duration and planned for extubation at the end of the surgery, will be enrolled for this study. They will be enrolled equally into either of the two groups- Magnesium Sulphate and Placebo. A computer-generated numbers list will randomise patients; allocation concealed with opaque sealed envelopes. The enrolled patients will undergo the Montreal Cognitive Assessment pre- and post-surgery. Patients with a score less than 26 will be excluded. Patients will be assessed for IL-6 and CRP pre- and post-surgery. Other assessments include optic nerve sheath diameter’s correlation with POD, length of ICU and hospital stay, analgesic requirement and complications between the groups. • Sample size- Based on previous literature and unpublished data from our institute on delirium, we estimated the baseline incidence of POD as 40% with an expected relative risk reduction post-intervention as 0.5. Considering a 1:1 allocation ratio, power of 80%, type I error (α) of 5% and expecting a minimal attrition rate of 10% the total number of patients needed to be recruited is 180 (i.e., 90 patients per group). • Discussion : This will be the first study in an oncological setup to assess the role of magnesium sulphate in POD. Previous studies on the role of delirium were inconclusive. This study's findings will help in reformations in our practice, if required. • Trial registration : CTRI/2023/10/058995, Clinical Trials Registry India. http://ctri.nic.in/Clinicaltrials/advsearch.php. Registered 20 ^th October, 2023.