Clean intermittent self-catheterization is an established option in bladder management of spinal cord injury patients. Several early and a small number of long-term studies have reported good preventive or therapeutic effects on hydronephrosis, vesicourethral reflux, urinary tract infection and incontinence. Most reports describe the use of small catheters and liberal use of jelly but urethral complications, such as strictures and false passages, seem to increase with the length of followup. All 30 spinal cord injury patients in this retrospective study had used disposable hydrophilic, low friction catheters from the early shock phase to a median of 7 years (range 5 to 9). There were 26 upper motor neuron and 4 lower motor neuron lesions. After tap water soaking, the surface layer of the catheter coating has a friction constant more than 10 times lower than that for a regular plastic catheter (Nélaton) with chlorhexidine jelly. There was no hydronephrosis, pyelonephritis or renal scarring. In 3 patients who had decreased the clean intermittent self-catheterization regimen, signs of upper tract dilatation developed but the excretory urogram returned to normal after correction of the regimen. Of 30 patients 12 (40%) maintained sterile urine, while 4 of the remaining 18 with bacteriuria had episodes of urinary sepsis and chronic infections. Two patients had epididymitis. Of 6 men with occasional insertion difficulties when the clean intermittent self-catheterization regimen started after the indwelling catheter had been removed 4 showed yielding signs of strictures during the subsequent clean intermittent self-catheterization regimen. In 1 patient 2 dilation attempts had failed but the patient can perform the clean intermittent self-catheterization regimen. One patient with Crohn's disease had advanced urethral changes in the acute phase but could perform clean intermittent self-catheterization with a small catheter. One patient has had recurrent modifications of the urethral wall but no development of a false passage. The study indicates that patients who use hydrophilic low friction low friction catheters do as well as or better than patients using conventional catheters. Above all, there is no increase in severe urethral complications with time after injury. Progression towards strictures after early urethral trauma seems to be preventable by the use of this catheter.

Pulmonary arterial hypertension (PAH) represents a chronic progressive disease characterized by high blood pressure in the pulmonary arteries leading to right heart failure. The disease has been a focus of medical research for many years due to its worse prognosis and limited treatment options. The aim of this study was to systematically assess the effects of different types of exercise interventions on PAH. Electronic databases were searched until July 2019. MEDLINE database was used as the predominant source for this paper. Studies with regards to chronic physical activity in adult PAH patients are compared on retrieving evidence on cellular, physiological, and psychological alterations in the PAH setting. Twenty human studies and 12 rat trials were identified. Amongst all studies, a total of 628 human subjects and 614 rats were examined. Regular physical activity affects the production of nitric oxygen and attenuates right ventricular hypertrophy. A combination of aerobic, anaerobic, and respiratory muscle training induces the strongest improvement in functional capacity indicated by an increase of 6 MWD and VO2 peak. In human studies, an increase of quality of life was found. Exercise training has an overall positive effect on the physiological and psychological components of PAH. Consequently, PAH patients should be encouraged to take part in regular exercise training programs.

The longterm use of clean intermittent self catheterisation as an option for bladder management in the care of spinal cord injury patients has shown the possible risk of urethral trauma and chronic infections being developed over time. The basic properties of the catheters being used need to be evaluated. In this crossover study of 14 male spinal cord injury patients, two commercial hydrophilic catheters were compared, as to the maximum friction force during the removal of the catheters after bladder emptying. The friction force, measured by a dynamometer twice daily, showed signi®cant lower values for LoFric (0.87/0.84 N) than for EsiCath/Conveen (1.38/1.27 N). Sticking to the urethral epithelium was reported three times (two patients) with the LoFric catheter, and 42 times (nine patients) with the EasiCath catheter. Osmolality of the outer layer of the catheters was measured using a freezing-point reduction technique. The greater than 10 times higher osmolality (*900 mOsm/kg) of the Lofric catheter may explain the results.Keywords: spinal cord injuries; urethral catheterisation; osmolality of catheters IntroductionIntermittent catheterisation (IC) and clean intermittent catheterisation (CIC) are the results of innovative ideas which have been most prevalent in the medical health and psycho-social life of spinal injury patients during the past 40 years. 1 ± 5 People's doubts surrounding new paradigms should be seen more as a result of tradition than a lack of technology for running conclusive, comparative studies. Nowadays, the technology exists but a decisive routine for starting randomised clinical trials is lacking in more or less the entire spinal injury area. Within the ®eld of neurology, detailed long-term follow-ups of the Lapides method have stated that urethral complications and chronic infections are dependent on the length of the regimen, 6 ± 9 while the hydrophilic CIC catheters could reduce these complications. 10,11 The time seems right for a comparative prospective clinical trial. 9 The hydrophilic catheter which has so far been tested (LoFric) seems to cause less short-term strains 12 and long-term trauma 10,11 and should logically reduce the risk of chronic prostatitis and epididymitis. 9,10 Positive results of self-catheterisaton have also been seen in stricture treatment following urethrotomy 13 including the low-friction variation. 14 Conclusive support for this requires prospective and su ciently large-scale studies over many years, where the optimal properties for the atraumatic performance of the catheters involved are tested and compared.This preparatory clinical study in a crossover design compares the friction during catheter removal between two commercial hydrophilic catheters as part of the spinal injury patient's usual bladder regimen during the post-injury phase.