Temperature and pressure influence on maximum rates of pressure rise during explosions of propane-air mixtures in a spherical vessel.

The maximum rates of pressure rise during closed vessel explosions of propane-air mixtures are reported, for systems with various initial concentrations, pressures and temperatures ([C(3)H(8)]=2.50-6.20 vol.%, p(0)=0.3-1.3 bar; T(0)=298-423 K). Experiments were performed in a spherical vessel (Φ=10 cm) with central ignition. The deflagration (severity) index K(G), calculated from experimental values of maximum rates of pressure rise is examined against the adiabatic deflagration index, K(G, ad), computed from normal burning velocities and peak explosion pressures. At constant temperature and fuel/oxygen ratio, both the maximum rates of pressure rise and the deflagration indices are linear functions of total initial pressure, as reported for other fuel-air mixtures. At constant initial pressure and composition, the maximum rates of pressure rise and deflagration indices are slightly influenced by the initial temperature; some influence of the initial temperature on maximum rates of pressure rise is observed only for propane-air mixtures far from stoichiometric composition. The differentiated temperature influence on the normal burning velocities and the peak explosion pressures might explain this behaviour.

[Complaints under analgesics: the difficult interpretation by older patients]. / Beschwerden unter Analgetika: Uber die schwierige Interpretation bei älteren Patienten.

BACKGROUND: Older patients, particularly those with multimorbidity, complain about many symptoms which also occur under analgesics (especially with opioids). The goals of the study were to quantify symptoms and discuss the relationships to analgesics, pain, multimorbidity, function, age and gender. PATIENTS AND METHODS: On admittance to geriatric hospital, 1700 consecutive inpatients were questioned about symptoms typically of side-effects of analgesics and pain. Additionally medication including analgesics, activities of daily living, orientation, age, gender and morbidity were recorded. RESULTS: Of the patients, 1,418 (mean age 80.9 years) could answer questions about symptoms. Disturbance of sleep (n=664, 46.8%), pain (n=609, 43.0%), low appetite (551, 37.4%), dizziness (482, 34%), tiredness (331, 19.7%), constipation (236, 16.6%) and problems of urination (213, 12.7%) were indicated most frequently. Univariate analysis showed the well known correlations of analgesics and symptoms to be dependent on dose and substances. However, using a multivariate model, analgesics lost the significance for the symptoms with some exceptions. Pain intensity, duration of pain and gender differences became more important. Vomiting, dry mouth, and problems with urination correlated with low levels of activities of daily living. Increasing morbidity and cognitive deficits were not important for many symptoms. CONCLUSIONS: Our results underline the difficult interpretation of symptoms as a side-effect of analgesic treatment in older patients. Pain and gender differences have to be considered. The recommendation to carefully record symptoms before analgesic treatment is supported by our results.

[Satisfaction of geriatric patients with their pain therapy. Wish and reality]. / Zufriedenheit geriatrischer Patienten mit ihrer Schmerztherapie. Wunsch und Wirklichkeit.

AIM: The goal of this study was to determine the level of satisfaction of geriatric patients with their pain therapy, their wishes for improved treatment, and possible influencing factors. METHODS: From April to November 2002, all patients able to communicate ( n=1432) were included in the study if they had reported pain in the previous 7 days or were taking regular analgesic medication without specifying pain. RESULTS: Of the geriatric patients reporting from home, 36.4% were not satisfied with their pain therapy up to that time, and 25.4% of surgical patients were dissatisfied as were 28.5% of patients treated in other departments. A total of 93.3% desired better pain treatment. Independent predictors for dissatisfaction with their therapy or wish for improvement were increasing pain intensity, frequent concomitant complaints in addition to pain, and the objectively perceived everyday competence. CONCLUSION: This study supports the observation that competent pain therapy is necessary and that there is room for improvement in geriatric facilities. Measuring pain intensity, posing questions pertaining to satisfaction with pain therapy, and determining whether patients desire better pain treatment are all indispensable for optimal care. Pain therapy should equally address reduction of pain intensity and management of other complaints.

[Recognizing pain in geriatric patients by an interdisciplinary team. Reliability of judgment and factors of influence]. / Schmerzerkennung bei geriatrischen Patienten durch ein interdisziplinäres Team: Urteilssicherheit und Einflussfaktoren.

The prevalence of chronic pain increases with age. The awareness of pain in geriatric patients is more difficult than in younger people because of various reasons. The occupational groups of the geriatric team might be different in respect of discerning symptoms of pain. 126 geriatric patients were enrolled in this study. They were asked if they had pain today and in the last seven days. At the same time the members of the geriatric team (old people's nurses, nurses, physicians, physio-, occupational and speech therapists) were asked the same questions with respect of their patients. Items possible influencing the answers were recorded: patient's characteristics: age, cognition (Folstein's minimental state) and duration of hospital stay before this interview; employee's characteristics: age, days of care in the past 7 days, weekly working hours, occupational years and years working in this geriatric hospital. The judgement of the geriatric team varied widely. It was dependent on the profession, days of care, weekly working hours and professional experience. Changes of care in the last 7 days have an negative effect in all occupational groups. Other features will be discussed in details. The handing of the patient's pain should be improved within the occupational groups.