Smartphone addiction in medical students: Association with perceived stress, personality factors and loneliness.

Background: Smartphone addiction (SMA) is an emerging concept. It has been associated with high perceived stress. There is a dearth of data on its association with loneliness and personality in the Indian context. Objectives: We planned this study to estimate the prevalence of SMA in medical students, verify its reported association with perceived stress, and determine its association with personality factors and loneliness. Methods: Four hundred and two medical students participated in this cross-sectional study. We used the SMA scale-short version to divide students into those having an addiction and not having an addiction. The Perceived Stress Scale, ten-item personality inventory, and University of California, Los Angeles Loneliness Scale were used to assess perceived stress, personality, and loneliness. Ninety-five percent confidence intervals were reported for all comparisons. Results: The prevalence of SMA in medical students was 34.8%. SMA was associated with higher perceived stress and loneliness. Students having SMA scored lower on personality domains of extraversion, agreeableness, conscientiousness, emotional stability, and openness to experience. Moreover, SMA interfered with students' social life and academic performance. Conclusions: SMA is a cause for concern. We need to plan the awareness campaigns focusing on SMA and its association with social life and academic performance. Researchers need to explore this concept in larger samples and diverse population groups to know its actual magnitude and impact. Moreover, dedicated psychiatric committees need to recommend the guidelines for the judicious use of smartphones.

Comparison of ropivacaine with and without fentanyl vs bupivacaine with fentanyl for postoperative epidural analgesia in bilateral total knee replacement surgery.

STUDY OBJECTIVES: Pain after total knee replacement (TKR) interferes with early rehabilitation. Although the use of epidural bupivacaine in post-TKR patients is associated with effective analgesia, the associated motor blockade effect delays functional recovery. We compared analgesic efficacy and side effects of postoperative patient-controlled epidural analgesia (PCEA) with plain ropivacaine 0.1% with/without fentanyl 2.5 µg/mL vs plain bupivacaine 0.0625% with fentanyl 2.5 µg/mL in patients undergoing bilateral TKR. DESIGN: Prospective, double-blind, randomized study. SETTINGS: Operation room, postoperative recovery room, and intensive joint replacement unit. PATIENTS: Ninety American Society of Anesthesiologists I to II post-TKR patients who were randomly allocated to receive postoperative PCEA with plain ropivacaine 0.1% (group 1), ropivacaine 0.1% with fentanyl 2.5 µg/mL (group 2), and plain bupivacaine 0.0625% with fentanyl 2.5 µg/mL (group 3). INTERVENTION: Postoperatively, the PCEA settings were standardized for a basal flow of 4 mL/h, demand dose of 6 mL, and lock-out interval of 20 minutes. "Rescue" analgesia included epidural boluses (6 mL) of respective study drug over and above PCEA administration. MEASUREMENTS: Postoperative pain profile, total PCEA drug used, heart rate, and noninvasive blood pressure, side effects, and patient satisfaction were recorded. MAIN RESULTS: Demographic parameters, duration of surgery, and hemodynamic variables (heart rate and noninvasive blood pressure) were comparable for the 3 study groups. Pain scores and rescue drug requirements were greater in "ropivacaine-only" group. Motor blockade was greatest in "bupivacaine-fentanyl" group. Postoperatively, despite the presence of minor side effects (nausea, itching) in the "ropivacaine-fentanyl" and bupivacaine-fentanyl groups, the patients belonging to these groups were more satisfied. CONCLUSION: After bilateral TKR, ropivacaine-fentanyl combination administered through a PCEA system resulted in "superior" analgesic efficacy, that is, pain relief without motor blockade, than "ropivacaine alone" (lesser pain relief) and bupivacaine-fentanyl (pain relief but with attendant motor blockade). Overall, the addition of fentanyl to epidural local anesthetic returned favorable postoperative analgesia profile and patient satisfaction with minor incidence of opioid-related side effects.

Shape and volume change in the transtibial residuum over the short term: preliminary investigation of six subjects.

A preliminary investigation was conducted to characterize the magnitude and distribution of volume change in transtibial residua at two time intervals: upon prosthesis removal and at 2 week intervals. Six adult male unilateral transtibial amputee subjects, between 0.75 and 40.0 years since amputation, were imaged 10 times over a 35-minute interval with a custom residual limb optical scanner. Volume changes and shape changes over time were assessed. Measurements were repeated 2 weeks later. Volume increase on socket removal for the six subjects ranged from 2.4% to 10.9% (median 6.0% +/- standard deviation 3.6%). Rate of volume increase was highest immediately upon socket removal and decreased with time (five subjects). In four subjects, 95% of the volume increase was reached within 8 minutes. No consistent proximal-to-distal differences were detected in limb cross-sectional area change over time. Limb volume differences 2 weeks apart ranged from -2.0% to 12.6% (0.6% +/- 5.5%) and were less in magnitude than those within a session over the 35-minute interval (five subjects). Multiple mechanisms of fluid movement may be responsible for short-term volume changes, with different relative magnitudes and rates in different amputees.

Processing computer tomography bone data for prosthetic finite element modeling: a technical note.

A software scheme is presented to extract the shapes of tibiae and fibulae from amputee computer tomography (CT) data for use in prosthetic finite element modeling. A snake algorithm is implemented to overcome challenges of bone-soft tissue edge detection common in this application. Means to enhance initial guess contours, ensure contour continuity, overcome point-clustering problems, and handle high-curvature regions are also described. Effectiveness of the algorithm is demonstrated on image data from a unilateral transtibial amputee subject.

A Three-Dimensional Finite Element Scheme to Investigate the Apparent Mechanical Properties of Trabecular Bone.

A computational technique is described for investigating the apparent mechanical properties of trabecular bone based on tissue geometry obtained from the marching cubes volume rendering scheme. Using this scheme, a 3D representation of the trabecular bone was extracted from two-dimensional cross-sections of the tissue originating from a quantitative serial sectioning procedure. Surface information consists of node coordinates and polygon connectivity in a 3D space. A custom, adaptive mesh generation technique using a normal offset was used to prepare 3D finite element volume meshes (4-node tetrahedral elements) of variable mesh density from the extracted surface geometry. Nine target mesh resolutions (32 µm to 107 µm) were examined for a (1.5 mmx 1.5 mmx 2 mm) volume of trabecular bone. A mesh density of 50,000 elements/mm(3) of bone tissue was found to be adequate for convergence of apparent (bulk) modulus for 1% uniaxial compression. For this convergent case, the maximum local normal compressive tissue stress was 400 MPa which was six hundred-fold greater than the computed apparent stress. Variation in the apparent modulus was less than 5% when Poisson's ratio values were varied between 0.1 and 0.4. Poisson's ratio values greater than 0.4 had a more marked effect on the apparent modulus. Based upon these results, approximately 1 million, 4-node tetrahedral elements are required to analyze a continuum scale model of trabecular bone (5 mm cube).