[Risk factors for back pain in children and adolescents]

Factors that have led to the increasing prevalence of back pain amongst children and adolescents living in industrialized nations are mostly unknown. The following literature review was aimed at determining the risk factors for back pain amongst children and adolescents. We searched both PUBMED and MEDLINE between the years 1985 and 2003 for the keywords "children or adolescents" and "back pain". Only data published in original articles were used. The risk for suffering back pain is influenced by physical, behavioural, emotional and social factors. The effects of physical activity, sitting, muscle status, weight of schoolbags, exercise, television and computer use, as well as age and gender on the development of back pain in children and adolescents were examined. Associations between continuous or recurring back pain and psychosocial factors (lifestyle, emotional factors, social relationships) could be demonstrated. There was no relationship between changes of the spine seen by radiological tests and the development of chronic back pain. Longitudinal epidemiological studies are urgently needed to delineate the risk factors for the development as well as the natural history of chronic back pain in the young.

[Continuous biochemical tissue monitoring during acute hypoxia]

Oxygen deficiency during critical illness is known to cause profound changes in cellular metabolism with subsequent organ dysfunction. Clinical treatment in these patients is focussed on rapid reoxygenation to avoid a prolonged impaired synthesis of cellular high-energy phosphates (ATP). The effect of this therapeutical intervention on the level of the cell, however, has not yet been objectivized. The aim of the present experimental study was to biochemically monitor different tissues during hypoxia and reoxygenation using in vivo microdialysis. Eighteen adult male CD-rats (412-469 g; Ivanovas, Kisslegg, Germany) were normoventilated under general anaesthesia (FiO2 = 0.21). Ten were then subjected to a period of hypoxia (FiO2 = 0.1, 40 min) and reoxygenated with FiO2 = 0.21, while eight control animals were continuously ventilated with FiO2 = 0.21. In addition to invasive haemodynamic monitoring, biochemical tissue monitoring was performed using CMA 20 microdialysis probes, which were inserted into the muscle (m), subcutaneous space (s), liver (l) and peritoneal cave (p) with semicontinuous analyses of lactate and pyruvate at intervals of 15 minutes. Hypoxia induced a significant decrease in mean arterial pressure compared to the control group (p < 0.05). At the same time significant increases in blood lactate (12.3 + 4.1 mmol/l (hypoxia) vs. 1.5 +/- 0.3 mmol/l (control); p < 0.05) and in negative base excess (17.3 + 7 mmol/l (hypoxia) vs. 2.6 + 1.8 mmol/l (control), p < 0.05) occurred. Compared to unchanged levels in the control animals, the interstitital lacate/pyruvate ratio in the investigation group rose to significantly higher values (455 + 199% of baseline (m), 468 + 148% (p), 770 + 218% (l) and 855 + 432% (s) (p < 0.05). An immediate return to the baseline values after the start of reoxygenation was noted in the L/P ratio during the observation period. Using microdialysis, it was possible to objectify the effect of oxygen deficiency and restoration on tissue metabolism. Regarding clinical and preclinical practice, microdialysis monitoring should be performed to include biochemical cellular effects as an additional target for therapeutical interventions.

[Comparison of severity of chronic pain in patients differing in pain diagnosis: an analysis by means of the Mainz Pain Staging System]

INTRODUCTION

Testing the validity of the Mainz Pain Staging System (MPSS) is often carried out by pain classification according to chronic stage. It is assumed that pain syndromes distribute equally over the chronic stages. This analysis was carried out to answer three questions: Do different pain syndromes vary in chronicity, do the four axes of the MPSS differ between pain syndromes, and are there any specific item responses with respect to a pain syndrome?

METHODS

406 patients with different pain diagnoses were included in this analysis. Patients were chosen from the PAIN-Documentation-System of the pain outpatients' department of the Medical University of Luebeck. The pain score according to MPSS had been assessed, and a diagnosis attributed according to the Multidimensional Classification of Pain (MASK).

RESULTS

Pain diagnoses do differ in pain chronification. Patients with headache showing the lowest chronification, and patients with back pain describing the most severe chronification, formed the extreme patient groups. Further analysis using the axes of the MPSS demonstrate different sensitivity with respect to pain syndromes, i. e. intake of drugs being the least sensitive and aspects of time being the most sensitive axes. Statistical analysis using configural frequency analysis indicated a relation between pain syndromes and specific item responses.

CONCLUSION

Using pain stages of the MPSS as an experimental factor in studies of pain, it is imperative either to control pain syndromes or to confine to a single pain syndrome, to avoid confusion between pain syndromes and severity of pain chronification.

[Computer assisted heart and circulation analysis in experimental septic shock (author's transl)]

Developping a model of shock applying to the clinical manifestation is necessary to investigate the pathogenesis of septic shock and to identify the letality causing organ. Perhaps the hyperkinetic syndrome may play an important role. The extensive experimental data is processed by a digital computer. Explanations are given for the experimental apparatus and the structure of the Fortran-program.