Performance of International Medical Students In psychosocial medicine.

BACKGROUND: Particularly at the beginning of their studies, international medical students face a number of language-related, social and intercultural challenges. Thus, they perform poorer than their local counterparts in written and oral examinations as well as in Objective Structured Clinical Examinations (OSCEs) in the fields of internal medicine and surgery. It is still unknown how international students perform in an OSCE in the field of psychosocial medicine compared to their local fellow students. METHODS: All students (N = 1033) taking the OSCE in the field of psychosocial medicine and an accompanying written examination in their eighth or ninth semester between 2012 and 2015 were included in the analysis. The OSCE consisted of four different stations, in which students had to perform and manage a patient encounter with simulated patients suffering from 1) post-traumatic stress disorder, 2) schizophrenia, 3) borderline personality disorder and 4) either suicidal tendency or dementia. Students were evaluated by trained lecturers using global checklists assessing specific professional domains, namely building a relationship with the patient, conversational skills, anamnesis, as well as psychopathological findings and decision-making. RESULTS: International medical students scored significantly poorer than their local peers (p < .001; η2 = .042). Within the specific professional domains assessed, they showed poorer scores, with differences in conversational skills showing the highest effect (p < .001; η2 = .053). No differences emerged within the multiple-choice examination (p = .127). CONCLUSION: International students showed poorer results in clinical-practical exams in the field of psychosocial medicine, with conversational skills yielding the poorest scores. However, regarding factual and practical knowledge examined via a multiple-choice test, no differences emerged between international and local students. These findings have decisive implications for relationship building in the doctor-patient relationship.

Heart rate changes as an autonomic component of the pain response.

Autonomic variables have been recommended as measures of the affective-motivational component of the pain response in objective algesimetry. In the present study components of heart rate responses to painful heat stimuli and their relation to stimulus and sensation variables were analyzed. Twelve healthy subjects served. Sixty phasic stimuli of varying temperatures above and below pain threshold were delivered through a Marstock thermode in 1 session. Heart rate, respiration, and subjective stimulus ratings were recorded simultaneously. Phasic heat stimulation above and below pain threshold induced a tonic increase of the heart rate lasting up to more than 20 sec. High intensity stimulation generated steeper rises and greater mean increase than low intensity stimulation. In general, heart rate responses were more closely related to subjective sensation than to stimulus intensity. However, differential temporal analysis demonstrates that, until about 3 sec after stimulation, the autonomic response is determined solely by stimulus temperature, whereas, after approximately 6 sec, it is related only to subjective judgement. Accordingly, the heart rate responses reflect both a brief nocifensive reflex induced by the sensory component and, subsequently, a longer-lasting response which seems to be related to affective and/or cognitive evaluation. This separation of different stages of pain-processing by an autonomic indicator may be useful in clinical algesimetry.

Psychophysical measures of sensitization to tonic heat discriminate chronic pain patients.

Sensitization to continued nociceptive stimulation is supposed to be involved in the development of chronic pain at several levels of the CNS, but experimental studies investigating the perceptual dynamics of sensitization in humans are rare, and the diagnostic validity of experimental pain models is not known. The present study used a tonic heat paradigm to assess early sensitization (15-100 s) to experimental pain in 30 chronic pain patients (15 musculoskeletal/back pain, 15 headache) and 23 healthy controls. Change in pain sensation during prolonged stimulation was measured by a dual sensitization method which combines subjective ratings and behavioural responses in an indirect psychophysical protocol protected against response bias. Phasic and tonic pain thresholds were measured for control purposes. The degree of sensitization was linearly related to stimulus temperature, and groups differed significantly in this 'sensitization gradient': chronic pain patients sensitized earlier and stronger than healthy subjects, musculoskeletal pain patients showed the strongest effect. Pain thresholds were lowered in headache patients only. Discriminant analysis demonstrated good sensitivity and specificity of individual sensitization measures for distinguishing pain syndromes, particularly in combination with pain thresholds. The results are in accordance with current models of spinal plasticity contributing to pathological pain states. They argue for the diagnostic value of psychophysical measures of sensitization.

Detection, discrimination and sensation of visceral stimuli.

Afferent visceral signals serve mostly regulatory functions and produce vague, diffuse body sensations, which are not well reflected in experimental paradigms requiring distinct and localized 'visceral perceptions'. A series of studies is summarized which compared behavioral discrimination of gastrointestinal distension stimuli with subjective sensation ratings in relation to basic perceptual operations such as detection, localization, graduation, and identification. Results showed that detection of gastrointestinal stimuli is possible without the subject's awareness (discrimination without reportable sensation). This process does not depend on stimulus intensity at volumes below those sufficient for subjective sensation. The latter is necessary, however, for intensity discrimination (graduation). Contrary to exteroception (e.g. vision), conscious subjective sensation is also required for stimulus localization. These differences in processing could not be explained by simple differences in response criteria. An intensity-dependent two-process model of gastrointestinal interoception is derived which differs from standard models of somatosensory information processing.

Somatovisceral interactions in visceral perception: abdominal masking of colonic stimuli.

Clinical and experimental evidence on referred pain and spinal-afferent convergence demonstrates a close relationship between visceral and somatosensory perception, which is important for current models of symptom perception and central body representation. The study uses a psychophysical approach to quantify these interactions at the perceptual level, taking into account problems of comparable intermodal scaling and the role of awareness. An experiment on somatosensory masking of distension stimuli in the colon is reported in which a multiple staircase method of forced choice discrimination with concurrent sensation ratings was employed. Results showed perceptual masking of visceral by abdominal stimuli but not vice versa. The masking effect was not enhanced by intratomal placement of the abdominal stimulus in the lower left quadrant. This contradicts the spinal sensory convergence model and points to perceptual interactions at higher brain levels. Loglinear analysis of relations between discrimination and subjective sensation revealed qualitative differences of somatovisceral perception at the preconscious as compared to the conscious level. This argues for a two-process model of integrative body perception.

Somatovisceral interactions in visceral perception: abdominal masking of colonic stimuli.

Clinical and experimental evidence on referred pain and spinal-afferent convergence demonstrates a close relationship between visceral and somatosensory perception, which is important for current models of symptom perception and central body representation. The study uses a psychophysical approach to quantify these interactions at the perceptual level, taking into account problems of comparable intermodal scaling and the role of awareness. An experiment on somatosensory masking of distension stimuli in the colon is reported in which a multiple staircase method of forced choice discrimination with concurrent sensation ratings was employed. Results showed perceptual masking of visceral by abdominal stimuli but not vice versa. The masking effect was not enhanced by intratomal placement of the abdominal stimulus in the lower left quadrant. This contradicts the spinal sensory convergence model and points to perceptual interactions at higher brain levels. Loglinear analysis of relations between discrimination and subjective sensation revealed qualitative differences of somatovisceral perception at the preconscious as compared to the conscious level. This argues for a two-process model of integrative body perception.

Effects of chronic back pain on the perception of experimental heat pain.

19 patients between 23 and 65 yr. of age whose chronic back pain was caused by lumbosacral disk disease and 19 healthy volunteers matched for age and sex were studied. Pain thresholds under phasic and tonic heat stimulation and thermal thresholds for warmth and cold were measured on the right hand. The patients rated any current back pain on a visual analog scale. There was a significant negative correlation between current back pain and the threshold for tonic pain, but there was no correlation between current back pain and either the threshold for phasic pain or temperature sensitivity. Hence, current back pain and experimental tonic pain seem to have an additive effect on pain perception because perceptual qualities are similar. Reduced somatosensory perception of chronic back pain patients could be demonstrated for temperature sensitivity and to a lesser degree for phasic pain, but as a consequence of the "opposing" effect of current back pain, not for tonic pain perception.

SDT analysis of experimental thermal pain, with "signal" and "no-signal" being determined psychophysically.

In a signal-detection experiment, the effects of repeated pain stimulation and the induction of fear on pain thresholds and SDT parameters were studied. "Signal" and "no-signal" were not defined physically, but by means of an independent criterion as the primary sensations "pain" and "no-pain." First, the relationship between sensation levels for "phasic" (short stimulus, used in the SDT procedure) and "tonic" (longer stimulus, used in the criterion measurement) heat stimuli was determined in 14 subjects. It was quadratic (polynomial regression) and sufficient to define the distinction between "signal/pain" and "no-signal/no-pain." In the signal-detection experiment, a significant upward trend (adaptation) in threshold parameters, but no systematic change in the SDT parameters (discrimination ability and response bias) was found. Manipulation of anxiety by instructions caused unsystematic changes in discrimination ability. The procedure employed determines both the absolute strength of pain sensation and the ability to discriminate pain from no pain. These variables proved to be independent.

Interoception, body perception and awareness. The heritage of György Adám.

UNLABELLED: Two series of studies are reported dealing with (1) psychophysical characteristics and (2) interactions of visceroceptive and somatosensoric information processing. The first studies characterized detection, graduation and localisation of visceral as compared to somatic stimuli. The second series investigated somatovisceral discrimination, masking, and summation at different levels of awareness. METHODS: Distension of the sigmoid colon served as standard model. The visceral stimulus was applied by a balloon probe in the sigmoid colon, the external abdominal stimulus by a ring-shaped stimulator at two abdominal sites. A forced-choice-paradigm with two observation intervals was applied (multiple staircase) to estimate interactions between somatosensation and visceroception. RESULTS: The visceral distension stimulus can be detected or discriminated correctly without conscious sensation. Visceral localization of stimuli requires conscious sensation. Combining visceral and somatic stimuli resulted in distinct elevation of visceral thresholds demonstrating somatosensory masking of the visceral stimulus. There are characteristic somato-visceral and viscero-somatic differences in masking and qualitative differences between implicit and explicit processing stages. Specific electrocortical reactions to visceral stimuli could be shown. DISCUSSION: Visceroception is represented on the highest functional level as a fairly independent submodality of body perception. There are several hints that visceroception and protopathic somatic sensitivity follow the same major paths and comprise the same ontogenetic origin. Perceptual interactions are determined by modality and awareness and depend on the task. The role of implicit and explicit body perception considering the body self and its significance in the context of consciousness are discussed.

Examination performances of German and international medical students in the preclinical studying-term--a descriptive study.

INTRODUCTION: Medical students with a migration background face several specific problems during their studies. International surveys show first indications that this group of students performs worse in written, oral or practical exams. However, so far, nothing is known about the performance of international students in written pre-clinical tests as well as in pre-clinical State Examinations for German-speaking countries. METHOD: A descriptive, retrospective analysis of the exam performances of medical students in the pre-clinical part of their studies was conducted at the Faculty of Medicine of Heidelberg in for the year 2012. Performance in written tests of the final exams in the second (N=276), third (N=292) and fourth semester (N=285) were compared between German students, students from EU countries and students from non-EU countries. Same comparison was drawn for the performance in the oral exam of the First State Examination in the period from 2009 - 2012 (N=1137). RESULTS: German students performed significantly better than students with a non-EU migration background both in all written exams and in the oral State Examination (all p<.05). The performance of students with an EU migration background was significantly better than that of students with a non-EU background in the written exam at the end of the third and fourth semester (p<.05). Furthermore, German students completed the oral exam of the First State Examination significantly earlier than students with a non-EU migration background (<.01). DISCUSSION: Due to its poorer performance in written and oral examinations and its simultaneously longer duration of study, the group of non-German medical students with a country of origin outside of the European Union has to be seen as a high-risk group among students with a migration background. For this group, there is an urgent need for early support to prepare for written and oral examinations.

Psychophysical features of the transition from pure heat perception to heat pain perception.

The psychophysical features of the transition from the pure heat to the heat pain range were studied in 25 healthy subjects (mean age 28.8 years). Thirty short heat stimuli from -1.6 degrees C to +1.6 degrees C relative to the pain threshold were applied to the thenar of the left hand with an apparatus containing a Peltier thermode (nine different temperatures at 0.4 degrees C intervals). The subjects rated the sensation intensity on a visual analogue scale. The resulting stimulus/sensation intensity relations could be explained equally well (same goodness of fit) by a model with a power function (PF) and by a model with two linear regression lines (TLR), one for stimulus intensities below and one for those above the pain threshold and intersecting at the pain threshold. The slopes of the TLR model were significantly larger above the pain threshold than below it. The PF model produced exponents between 1.8 and 1.9. We conclude that to describe the transition area, it is sufficient to use simple linear models for both the pure heat and the heat pain ranges.

[Anesthesia in geriatric patients. The determination of physiological variables for cognitive function in geriatric patients after regional or general anesthesia]. / Anästhesie bei geriatrischen Patienten. Die Bedeutung physiologischer Variablen für die kognitive Leistungsfähigkeit geriatrischer Patienten nach Regionaloder Allgemeinanästhesie.

OBJECTIVE: The aim of the present study was to show the influence of the parameters of gas exchange (arterial oxygen pressure paO2, arterial oxygen saturation SatO2) and haemodynamics (arterial systolic and mean blood pressure RRs and MAP) on the restitution of cognitive functions in geriatric patients scheduled for elective hip arthroplasty. METHODS: A total of 30 patients (70 years, ASA II) were randomized to be operated either in regional anaesthesia (n = 15) or general anaesthesia (n = 15). PaO2 (by capillary blood gas analysis), RRs and MAP (by oscillometry) were measured 15 and 90 minutes after arrival in the recovery unit (t1 and t2), 24 and 72 hours postoperatively (t3 and t4), and cognitive functions were tested. Intraoperatively, throughout the day and the first night after surgery we measured satO2 by continuous pulse oximetry. We recorded MAP and RRs by oscillometry every 3 minutes during the operation and every 15 minutes for the rest of that day and night. RESULTS: The parameters of gas exchange and haemodynamics did not differ among the groups. PaO2 was significantly reduced in both groups compared to baseline 24 hours postoperatively (t3) and remained low until 72 hours postoperatively (t4). Nearly all cognitive functions were significantly reduced in both groups compared to baseline 15 and 90 minutes after arrival in the recovery unit (t1 and t2), but recovered on the first postoperative day (t3). Both groups kept deficits in verbal memory and reading capacity up to the third postoperative day (t4). There was no correlation between the physiological parameters and the restitution of the tested cognitive functions. CONCLUSION: The restitution of cognitive functions during the first three postoperative days in geriatric patients scheduled for elective hip surgery does not depend on the anaesthetic technique. According to our results regional anaesthesia does not show any advantage for geriatric patients undergoing elective hip arthroplasty.