Demographics, preoperative psychometric tests, and P300 latency and amplitude
Visual Retention
This prospective randomized controlled trial was conducted on 80 patients indicated for septoplasty under general anesthesia. Forty patients received intra-operative Nitroglycerine (Nitroglycerine group), and 40 patients received intra-operative Phentolamine (Phentolamine group). Consort flow diagram is illustrated in Fig. (1). The median value for age in the Nitroglycerine group was 29 years with IQR (25.25-35) years, and in the Phentolamine group was 33.5 years with IQR (27–38) years. 20 (50%) patients in the Nitroglycerine group were males, and 20 (50%) were females. Whereas 25 (62.5%) patients in the Phentolamine group were males and 15 (37.5%) were females. There was no statistically significant difference between both groups in either age or sex (P-value = 0.193, 0.26 respectively) (Table 
CONSORT 2010 Flow Diagram
Demographics, pre-operative psychometric tests, and pre-operative P300 latency and amplitude in patients in Nitroglycerine and Phentolamine groupsPre-operative PALT[Median (IQR)]Values are expressed as median (Q1-Q3), number (%)PALT: Paired Associate Learning Test, BVRT: Benton Visual Retention TestMann-Whitney test was used for comparison between quantitative variables, Chi-squared test was used for comparison between categorical variables, P-value > 0.05 is considered in-significant