RESUMEN
A hollow fibre (HF) polypropylene membrane gas absorber was investigated for the removal of hydrogen sulphide (H2S) from gas streams. Gas concentrations between 25-2010 ppmV were fed into the shell side of a membrane module whilst water-NaOH solutions flowed counter-currently in the fibre lumens. The process was effective at removing the H2S (96% at G:L ratios up to 50 and pH 13) from the gas phase in a single pass through the membrane at all the concentrations of HaS investigated. Analysis of the mass transfer process revealed the rate of transfer to be controlled by the gas phase transfer coefficient with a value between 1 and 25 x 10(-4) m.s(-1). The possible integration of a membrane absorber system into existing odour treatment strategies was assessed by comparing the membrane system, based on the experimentally determined mass transfer coefficient, with existing full scale biofiltration plants. The membrane system became economically favourable at gas flow rates lower than 1630 m(3) x h(-1).
Asunto(s)
Contaminantes Atmosféricos/aislamiento & purificación , Sulfuro de Hidrógeno/aislamiento & purificación , Odorantes/prevención & control , Eliminación de Residuos Líquidos/métodos , Adsorción , Control de Costos , Ensayo de Materiales , Membranas Artificiales , Polipropilenos , Eliminación de Residuos Líquidos/economíaRESUMEN
BACKGROUND: Fentanyl is a synthetic opioid, suitable for transdermal delivery, offering an interesting solution as a step 3 opioid in cancer pain treatment. The purpose of the study was to carefully investigate: 1) the feasibility of the direct conversion from codeine to TTS fentanyl, in patients already receiving codeine and requiring strong opioids for their analgesia; 2) the safety of 25 microg/hour incremental steps and at shorter than 72-hour intervals, if clinically required. PATIENTS AND METHODS: 130 patients were judged eligible for the study. All the patients were receiving 280-360 mg or more of codeine and required strong opioid for their analgesia. The study lasted 56 days. The initial dose was 25 microg/hour. TTS fentanyl for all patients. Data assessments were made on baseline, day 1, day 2, day 3, in the hospital and thereafter on days 7, 14, 21, 28, 42 and 56. After the patch application, all the patients were given an immediate release oral morphine (5 mg) every 4-6 hours for the first 12 hours and then if needed only as rescue doses. The patients remained in the hospital for the first three days of the study where follow-up (pain score, satisfaction, side effects etc.). was recorded by the palliative care team and by daily cards. RESULTS: The itnitial dose of fentanyl was 25 microg/hour while the mean dose on day 3 was 45.9 microg/hour. All the patients required upward titration of the study medication during follow-up visits. On day 56 the mean dose of fentanyl was 87.4 microg/hour. Mean pain intensity decreased from an initial 5.96 on the baseline to 0.83 on day 3. Karnofsky scale measurements between treatment phases revealed non-significant changes. The rate of overall satisfaction was quite high. Nine patients discontinued the study due to inadequate pain relief or side effects between day 7 and day 28, while five patients died between day 28 and day 56. Constipation, nausea and vomiting were the most common side effects. Skin reaction was relatively mild and acceptable during the study. CONCLUSION: Under controlled conditions, TTS fentanyl seems to be feasible for direct conversion from mild to strong opioids and additionally, 25 microg/hour incremental steps day by day can be made by palliative care specialists, if clinically required for cancer pain management.
Asunto(s)
Analgésicos Opioides/administración & dosificación , Codeína/uso terapéutico , Fentanilo/administración & dosificación , Neoplasias/complicaciones , Dolor Intratable/tratamiento farmacológico , Administración Cutánea , Adulto , Anciano , Anciano de 80 o más Años , Analgésicos Opioides/efectos adversos , Esquema de Medicación , Femenino , Fentanilo/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Dimensión del Dolor/efectos de los fármacos , Dolor Intratable/etiología , Estudios ProspectivosRESUMEN
BACKGROUND: Pain is prevalent in cancer patients. Although the World Health Organization has issued guidelines for treating pain in cancer patients, pain is often not treated optimally. Numerous barriers have been identified that prevent health care professionals from providing effective treatment for pain. The knowledge and attitudes of health care professionals with regard to pain and its impact on the patient are among them. The purpose of the present study was to evaluate knowledge about and attitudes toward cancer pain and its management among Greek oncologists, surgeons, anesthesiologists, and general practitioners. METHOD: Knowledge of the principles and methods of cancer pain treatment was assessed by a questionnaire distributed to a representative sample of 1,200 Greek physicians. RESULTS: The study results highlight very substantial knowledge deficits in the treatment of cancer pain by the evaluated physicians. CONCLUSIONS: Cancer pain management in Greece is still developing, and the latest knowledge is spreading slowly but steadily.