Descriptive statistics are an important part of biomedical research which is used to describe the basic features of the data in the study. They provide simple summaries about the sample and the measures. Measures of the central tendency and dispersion are used to describe the quantitative data. For the continuous data, test of the normality is an important step for deciding the measures of central tendency and statistical methods for data analysis. When our data follow normal distribution, parametric tests otherwise nonparametric methods are used to compare the groups. There are different methods used to test the normality of data, including numerical and visual methods, and each method has its own advantages and disadvantages. In the present study, we have discussed the summary measures and methods used to test the normality of the data.

Student's t test (t test), analysis of variance (ANOVA), and analysis of covariance (ANCOVA) are statistical methods used in the testing of hypothesis for comparison of means between the groups. The Student's t test is used to compare the means between two groups, whereas ANOVA is used to compare the means among three or more groups. In ANOVA, first gets a common P value. A significant P value of the ANOVA test indicates for at least one pair, between which the mean difference was statistically significant. To identify that significant pair(s), we use multiple comparisons. In ANOVA, when using one categorical independent variable, it is called one-way ANOVA, whereas for two categorical independent variables, it is called two-way ANOVA. When using at least one covariate to adjust with dependent variable, ANOVA becomes ANCOVA. When the size of the sample is small, mean is very much affected by the outliers, so it is necessary to keep sufficient sample size while using these methods.

A single preoperative oral dose of pregabalin 150 mg is an effective method for reducing postoperative pain and fentanyl consumption in patients undergoing laparoscopic cholecystectomy.

P Pu ur rp po os se e: : To evaluate the comparative preemptive effects of gabapentin and tramadol on postoperative pain and fentanyl requirement in laparoscopic cholecystectomy.M Me et th ho od ds s: : Four hundred fifty-nine ASA I and II patients were randomly assigned to receive 300 mg gabapentin, 100 mg tramadol or placebo in a double-blind manner two hours before laparoscopic cholecystectomy under general anesthesia. Postoperatively, patients' pain scores were recorded on a visual analogue scale every two hours for the initial 12 hr and thereafter every three hours for the next 12 hr. Patients received fentanyl 2 µg·kg -1 intravenously on demand. The total fentanyl consumption for each patient was recorded.R Re es su ul lt ts s: : Patients in the gabapentin group had significantly lower pain scores at all time intervals (2.65 ± 3.00, 1.99 ± 1.48, 1.40 ± 0.95, 0.65 ± 0.61) in comparison to tramadol (2.97 ± 2.35, 2.37 ± 1.45, 1.89 ± 1.16, 0.87 ± 0.50) and placebo (5.53 ± 2.22, 3.33 ± 1.37, 2.41 ± 1.19, 1.19 ± 0.56). Significantly less fentanyl was consumed in the gabapentin group (221.16 ± 52.39 µg) than in the tramadol (269.60 ± 44.17 µg) and placebo groups (355.86 ± 42.04 µg; P < 0.05). Sedation (33.98%), nausea/retching/vomiting (24.8%) were the commonest side effects in the gabapentin group whereas respiratory depression (3.9%) was the commonest in the tramadol group and vertigo (7.8%) in the placebo group. C Co on nc cl lu us si io on n: : Preemptive use of gabapentin significantly decreases postoperative pain and rescue analgesic requirement in laparoscopic cholecystectomy. (2,65 ± 3,00; 1,99 ± 1,48; 1,40 ± 0,95; 0,65 ± 0,61) que ceux du groupe tramadol (2,97 ± 2,35; 2,37 ± 1,45; 1,89 ± 1,16; 0,87 ± 0,50) ou placebo (5,53 ± 2,22; 3,33 ± 1,37; 2,41 ± 1,19; 1,19 ± 0,56). La demande de fentanyl a été significativement plus basse avec la gabapentine (221,16 ± 52,39 µg) qu'avec le tramadol (269,60 ± 44,17 µg) ou le placebo (355,86 ± 42,04 µg; P < 0,05). La sédation (33,98 %), les nausées/haut-lecoeur/vomissements (24,8 %) ERIPHERAL tissue injury provokes peripheral sensitization (a reduction in the threshold of nociceptor afferent peripheral terminals) and central sensitization (an activity dependent increase in the excitability of spinal neurons). 1,2 These changes contribute to the postinjury pain hypersensitivity state which manifests as an increase in the responsiveness to noxious stimuli and a decrease in the pain threshold, both at the site of injury and in the surrounding uninjured tissue. 1,2 The optimal form of treatment is that applied pre, intra and postoperatively to preempt the establishment of pain hypersensitivity during and after surgery. The preemptive treatment could be directed at the periphery, at inputs along sensory axons, and at central neurons. Different treatment regimens could be used at different times relative to surgery to maximize the prevention of pain in response to different levels of sensory inputs. 1,2 Gabapentin and tramadol both have demonstrated analgesic effect...

We evaluated the optimal preemptive dose of gabapentin for postoperative pain relief after single-level lumbar diskectomy and its effect on fentanyl consumption during the initial 24 hours in a randomized, double-blinded, placebo-controlled study in 100 patients with American Society of Anesthesiologists physical status I and II. Patients were divided into five groups to receive placebo or gabapentin 300, 600, 900, or 1200 mg 2 hours before surgery. After surgery, patients were transferred to the postanesthesia care unit (PACU). A blinded anesthesiologist recorded the pain scores at time points of 6, 12, 18, and 24 hours in the PACU on a Visual Analog Scale (VAS; 0-10 cm) at rest. Patients received patient-controlled analgesia (fentanyl 1.0 mug/kg on each demand with lockout interval of 10 minutes); total fentanyl consumption during initial 24 hours was recorded. Data were entered into the statistical software package SPSS 9.0 for analysis (one-way analysis of variance and Student-Newman-Keuls test). Patients who received gabapentin 300 mg had significantly lower VAS score at all time points. They consumed less fentanyl (patients who received placebo processed 1217.5 +/- 182.0 versus 987.5 +/- 129.6 mug; P < 0.05). Patients who received gabapentin 600, 900, and 1200 mg had lower VAS scores at all time points than patients who received gabapentin 300 mg (P < 0.05). Increasing the dose of gabapentin from 600 to 1200 mg did not decrease the VAS score, nor did the increasing dose of gabapentin significantly decrease fentanyl consumption (702.5, 635, and 626.5 microg). Thus, gabapentin 600 mg is the optimal dose for postoperative pain relief following lumbar diskectomy.