Total skin electron therapy (TSET): a reimplementation using radiochromic films and IAEA TRS-398 code of practice.

PURPOSE: The aim of this work is to present an updated implementation of total skin electron therapy (TSET) using IAEA TRS-398 code of practice for absolute dosimetry and taking advantage of the use of radiochromic films. The optimization of quality control tests is also included. METHODS: A Varian 2100 C/D linear accelerator equipped with the special procedure HDTSe- (high dose rate total skin electron mode, E=6 MeV) was employed to perform TSET irradiations using the modified Stanford technique. The commissioning was performed following the AAPM report 23 recommendations. In particular, for dual-field beams irradiation, the optimal tilt angle was investigated and the dose distribution in the treatment plane was measured. For a complete six dual-field beams irradiation, the treatment skin dose on the surface of a cylindrical phantom was evaluated by radiochromic films and the B factor which relates the single dual-field skin dose to the six dual-field skin dose was assessed. Since the TRS-398 reference conditions do not meet the requirements of TSET absolute dosimetry, GafChromic EBT films were also employed to check and validate the application of the protocol. Simplified procedures were studied to verify beam constancy in PMMA phantoms without the more difficult setup of total skin irradiation. RESULTS: The optimized geometrical setup for dual-field beams was: Tilt angle = +/- 19 degrees, SSD=353 cm, and the beam degrader (200 x 100 X 1 cm3) placed at 320 cm from the source. As regards to dose homogeneity in the treatment plane, for dual-field beams irradiation, the mean relative dose value was 97% +/- 5% (normalizing to 100% at the calibration point level). For six dual-field beams irradiation, the multiplication factor B was 2.63. In addition, beam quality, dose rate, and bremsstrahlung contribution were also suitable for TSET treatments. The TRS-398 code of practice was used for TSET dosimetry, as dose measurements performed by ionization chamber and radiochromic film agreed within 2.5%. Simplified quality control tests and baseline values were presented in order to check flatness, symmetry, and field size with radiochromic films and output and beam quality constancy with ionization chamber. Short-term reproducibility and MU linearity tests were also included. CONCLUSIONS: Commissioning parameters met the requirements of TSET treatments and the matching of AAPM guidelines with the IAEA code of practice was successful. Frequent beam performance controls can be easily performed through the presented quality assurance tests. Radiochromic dosimetry facilitated the TSET commissioning and played a major role to validate the application of TRS-398.

The need to improve inhalation technique in Europe: a report from the Aerosol Drug Management Improvement Team.

Although the principles of asthma management are well established in Europe, the available data indicate that asthma in patients is not well controlled. Many patients derive incomplete benefit from their inhaled medication because they do not use inhaler devices correctly and this may compromise asthma control. The Aerosol Drug Management Improvement Team (ADMIT), incorporating clinicians from the UK, Germany, France, Italy, Spain and The Netherlands, reviewed published evidence to examine ways to improve the treatment of reversible airways disease in Europe. Data indicate that there is a clear need for specific training of patients in correct inhalation technique for the various devices currently available, and this should be repeated frequently to maintain correct inhalation technique. Devices which provide reassurance to patients and their physicians that inhalation is performed correctly should help to improve patient compliance and asthma control. Educational efforts should also focus on primary prescribers of inhaler devices. ADMIT recommends dissemination of information on the correct inhalation technique for each model of device by the use of an accessible dedicated literature base or website which would enable to match the appropriate inhaler to the individual patient. There is also a need for standardisation of prescribing practices throughout Europe. Regular checking of inhalation technique by prescribers is crucial as correct inhalation is one of the keystones of successful asthma management.

Avaliação algimétrica e sinérgica em cães tratados pela levomepromazina, induzidos pelo tiopental e mantidos pelo sevofluorano, pré-tratados ou não pelo butorfanol

O artigo não apresenta resumo.

Ablação de granuloma bacteriano dos seios paranasais em equino

O artigo não apresenta resumo.

Contact sensitization to disperse dyes in children.

From January 1996 to December 2000, 1098 children, including 667 subjects with suspected allergic contact dermatitis and 431 patients with atopic dermatitis (AD), were patch tested with seven disperse dyes: disperse blue 124 (DB124), disperse blue 106 (DB106), disperse red 1 (DR1), disperse yellow 3 (DY3), disperse orange 3 (DO3), p-aminoazobenzene (PAAB), and p-dimethylaminoazobenzene (PDAAB). Of these, 51 patients (4.6%; 34 girls and 17 boys) proved sensitized to disperse dyes. AD or history of AD was present in 30 patients (59%). The most common sensitizer was DY3 (17 patients), followed by DO3 (15 patients), and DB124 (14 patients). Among dye-positive patients, about 12% were sensitized to disperse dyes alone and only 14% reacted to para-phenylenediamine. In disperse dye-sensitive children not affected by AD, the feet, axillae, and groin appeared to be the most common localizations, whereas in those with AD, involvement of the face and the flexural areas of the limbs was more common. In conclusion, our study showed that in children with suspected contact sensitization, disperse dyes should be regarded as potential triggering allergens.

Sensitization to disperse dyes in a patch test population over a five-year period.

BACKGROUND: In spite of sporadic data pointing at the role of textile dyes as important contact allergens, only few studies have addressed the issue of the frequency of sensitization to textile dyes in populations of consecutive patients. OBJECTIVE: The purpose of this study was to evaluate the prevalence of sensitization to disperse dyes, to investigate cross reactivity between azo dyes and para-amino compounds, to describe azo-dye-positive patients, and to study the correlation between clinical aspects and sensitization to different disperse dyes. METHODS: From January 1996 to December 2000, 6,478 consecutive patients were tested with 7 textile dyes: Disperse Blue 124, Disperse Blue 106, Disperse Red 1, Disperse Yellow 3, Disperse Orange 3 (DO3), para-aminoazobenzene (PAAB), and para-dimethylaminoazobenzene (PDAAB). RESULTS: Of the above, 437 patients were allergic. The most common sensitizers were Disperse Blue (DB) dyes and Disperse Orange 3. Both the clinical aspect and the localization of the lesions were unusual in a fair percentage of cases, especially in DB-positive subjects. Involvement of skin folds was observed in 27% of disperse dye-positive patients, mainly comprising DB-sensitive women. Cross-reactivity between azo-dyes and paraphenylenediamine (PPD) was frequent in DO3-, PAAB-, and PDAAB-positive subjects, but not in DB-allergic ones. Moreover, cross reactions between DB106 and DB124 were observed in 59% of DB106- and/or DB124-positive patients. CONCLUSIONS: The frequency of disperse dye allergy is higher than generally estimated. Further studies, using routine diagnostic testing with disperse dyes, are needed to investigate whether this increasing trend is present outside of Europe.

The effects of atropine and methotrimeprazine on the epinephrine-induced arrhythmias in halothane-anesthetized dogs.

The effects of atropine and methotrimeprazine on epinephrine-induced ventricular arrhythmias were evaluated in halothane-anesthetized dogs. Ten mixed-breed dogs were assigned to 3 treatments (saline, atropine, and methotrimeprazine) in a randomized complete block design. Anesthesia was induced and maintained with halothane (1.5 minimum alveolar concentration) in oxygen. Controlled ventilation was used throughout to maintain eucapnia. Saline, atropine (0.05 mg/kg, i.v.) or methotrimeprazine (0.5 mg/kg, i.v.) were administered and, 5 minutes later the arrhythmogenic dose of epinephrine (ADE) was measured by i.v. infusion of progressively increasing infusion rates of epinephrine, until the ventricular arrhythmia criterion was met (at least 4 ectopic ventricular contractions (EVCs) during a 15-second period). Data were analyzed using a student's t-test for ADE values and multivariate profile analysis for heart rate (HR), arterial blood pressure (ABP), and rate pressure product (RPP). The ADE increased in atropine- and methotrimeprazine-treated groups, whereas 1 and 4 animals from these groups did not develop any ventricular arrhythmia, respectively. Epinephrine induced multiform premature ventricular contractions (PVCs) in the atropine group, whereas ventricular escape beats were observed in the control and methotrimeprazine groups. Heart rate and RPP decreased, and ABP increased at the time of ADE observation in the control group. Epinephrine infusion in the atropine group caused marked increases in HR, ABP, and RPP, which were associated with pulsus alternans in 2 animals. It was concluded that 1) the presence of cholinergic blockade influences the type of ventricular arrhythmia induced by epinephrine; 2) increased ADE values recorded following atropine administration must be cautiously interpreted, since in this situation the PVCs were associated with signs of increased myocardial work and ventricular failure; and 3) the use of a broader arrhythmia criterion (EVCs instead of PVCs) may not allow a direct comparison between ADE values, since it includes ventricular arrhythmias mediated by different mechanisms.

A preliminary trial comparison of several anesthetic techniques in cats.

The aim of this study was to investigate the effect of several drug combinations (atropine, xylazine, romifidine, methotrimeprazine, midazolam, or fentanyl) with ketamine for short term anesthesia in cats. Twelve cats were anesthetized 6 times by using a cross-over Latin square protocol: methotrimeprazine was combined with midazolam, ketamine, and fentanyl; midazolam and ketamine; romifidine and ketamine; and xylazine and ketamine. Atropine was combined with romifidine and ketamine, and xylazine and ketamine. Temperature, heart rate, and respiratory rate decreased in all groups. Apnea occurred in 1 cat treated with methotrimeprazine, romifidine, and ketamine, suggesting that ventilatory support may be necessary when this protocol is used. Emesis occurred in some cats treated with alpha 2-adrenoceptor agonists, and this side effect should be considered when these drugs are used.

Avaliaçäo cardiocirculatória do sevofluorano como agente de manutençäo anestésica em cäes, em diferentes concentraçöes de oxigênio e óxido nitroso / Sevoflurane cardiocirculatory study in dog with different oxygen and nitrous oxide concentrations

Com o objetivo de avaliar as alteraçöes cardiocirculatórias resultantes da manutençäo anestésica com sevofluorano, três grupos de 10 cäes cada foram anestesiados por 60 minutos com fluxo diluente de 100 por cento de oxigênio (grupo 1), de 50 por cento de oxigênio e de óxido nitroso (grupo 2) ou 27 por cento de oxigênio e 63 por cento de óxido nitroso (grupo 3). A tranqüilizaçäo foi realizada com levomepromazina (0,5 mg/kg) e a induçäo com tiopental (12,5 mg/lg). A freqüência cardíaca apresentou elevaçäo significativa após a induçäo (P<0,05), mantendo-se mais alta que a basal, em todos os grupos, durante toda a anestesia. As variaçöes das pressöes arteriais sistólica, média e diastólica foram pouco significativas e mantiveram-se em todos os grupos dentro de valores aceitáveis para a espécie e a utilizaçäo do óxido nitroso näo interferiu nessa variaçäo. O sevofluorano demonstrou ser um bom agente de manutençäo anestésica em cäes, e a adiçäo de 63 por cento de óxido nitroso ao fluxo diluente de oxigênio reduziu a necessidade anestésica de maneira significativa

The effect of changing the mode of ventilation on the arterial-to-end-tidal CO2 difference and physiological dead space in laterally and dorsally recumbent horses during halothane anesthesia.

OBJECTIVE: To evaluate the effect of changing the mode of ventilation from spontaneous to controlled on the arterial-to-end-tidal CO2 difference [P(a-ET)CO2] and physiological dead space (VD(phys)/VT) in laterally and dorsally recumbent halothane-anesthetized horses. STUDY DESIGN; Prospective, experimental, nonrandomized trial. ANIMALS: Seven mixed breed adult horses (1 male and 6 female) weighing 320 +/- 11 kg. METHODS: Horses were anesthetized in 2 positions-right lateral and dorsal recumbency-with a minimum interval of 1 month. Anesthesia was maintained with halothane in oxygen for 180 minutes. Spontaneous ventilation (SV) was used for 90 minutes followed by 90 minutes of controlled ventilation (CV). The same ventilator settings were used for both laterally and dorsally recumbent horses. Arterial blood gas analysis was performed every 30 minutes during anesthesia. End-tidal CO2 (PETCO2) was measured continuously. P(a-ET)CO2 and VD(phys)NT were calculated. Statistical analysis included analysis of variance for repeated measures over time, followed by Student-Newman-Keuls test. Comparison between groups was performed using a paired t test; P < .05 was considered significant. RESULTS: P(a-ET)CO2 and VD(phys)/VT increased during SV, whereas CV reduced these variables. The variables did not change significantly throughout mechanical ventilation in either group. Dorsally recumbent horses showed greater P(a-ET)CO2 and VD(phys)/VT values throughout. PaCO2 was greater during CV in dorsally positioned horses. CONCLUSIONS AND CLINICAL RELEVANCE: Changing the mode of ventilation from spontaneous to controlled was effective in reducing P(a-ET)CO2 and physiological dead space in both laterally and dorsally recumbent halothane-anesthetized horses. Dorsal recumbency resulted in greater impairment of effective ventilation. Capnometry has a limited value for accurate estimation of PaCO2 in anesthetized horses, although it may be used to evaluate pulmonary function when paired with arterial blood gas analysis.

Midazolam and ketamine induction before halothane anaesthesia in ponies: cardiorespiratory, endocrine and metabolic changes.

Six Welsh gelding ponies were premedicated with 0.03 mg/kg of acepromazine intravenously (i.v.) prior to induction of anaesthesia with midazolam at 0.2 mg/kg and ketamine at 2 mg/kg i.v.. Anaesthesia was maintained for 2 h using 1.2% halothane concentration in oxygen. Heart rate, electrocardiograph (ECG), arterial blood pressure, respiratory rate, blood gases, temperature, haematocrit, plasma arginine vasopressin (AVP), dynorphin, beta-endorphin, adrenocorticotropic hormone (ACTH), cortisol, dopamine, noradrenaline, adrenaline, glucose and lactate concentrations were measured before and after premedication, immediately after induction, every 20 min during anaesthesia, and at 20 and 120 min after disconnection. Induction was rapid, excitement-free and good muscle relaxation was observed. There were no changes in heart and respiratory rates. Decrease in temperature, hyperoxia and respiratory acidosis developed during anaesthesia and slight hypotension was observed (minimum value 76 +/- 10 mm Hg at 40 mins). No changes were observed in dynorphin, beta-endorphin, ACTH, catecholamines and glucose. Plasma cortisol concentration increased from 220 +/- 17 basal to 354 +/- 22 nmol/L at 120 min during anaesthesia; plasma AVP concentration increased from 3 +/- 1 basal to 346 +/- 64 pmol/L at 100 min during anaesthesia and plasma lactate concentration increased from 1.22 +/- 0.08 basal to 1.76 +/- 0.13 mmol/L at 80 min during anaesthesia. Recovery was rapid and uneventful with ponies taking 46 +/- 6 min to stand. When midazolam/ketamine was compared with thiopentone or detomidine/ketamine for induction before halothane anaesthesia using an otherwise similar protocol in the same ponies, it caused slightly more respiratory depression, but less hypotension. Additionally, midazolam reduced the hormonal stress response commonly observed during halothane anaesthesia and appears to have a good potential for use in horses.

A combination of methotrimeprazine, midazolam and guaiphenesin, with and without ketamine, in an anaesthetic procedure for horses.

A combination of 0.5 mg/kg of methotrimeprazine, 0.1 mg/kg of midazolam and 100 mg/kg of a 10 per cent guaiphenesin solution was investigated for the induction of recumbency in 15 horses; the addition of 1.6 mg/kg of ketamine was also evaluated in 15 horses and anaesthesia was maintained with halothane in oxygen. The horses became recumbent quickly and smoothly and they recovered quietly, with little ataxia. Tachycardia occurred after induction, but no other changes from pre-operative values were observed until halothane in oxygen had been given, when hypothermia, hypotension, bradypnoea, hyperoxaemia, respiratory acidosis and decreased respiratory minute volume developed. Horses given ketamine in addition to methotrimeprazine, midazolam and guaiphenesin were easier to intubate and recovered more quickly than horses receiving only methotrimeprazine, midazolam and guaiphenesin.

Efeitos do midazolam sobre o sistema cardiovascular em cäes pré-medicados com levomepromazina / Cardiovascular effects of midazolan in levomepromazine premedicated dogs

Foram utilizados 10 cäes adultos, de ambos os sexos, sem raça definida, com peso corpóreo entre 10 e 18 kg. Os animais foram pré-medicados com 1,0 mg/kg de levomepromazina e 15 minutos após receberam 2,0 mg/kg de midazolam, ambos por via intravenosa. A freqüência respiratória mostrou um aumento moderado e a freqüência cardíaca reduçäo aos 15 minutos e elevaçäo aos 30 minutos. Houve reduçäo da pressäo arterial média e da pressäo sistólica com significado estatístico e näo clínico. Houve tendência de reduçäo da pressäo arterial diastólica. A hipnose durou aproximadamente 20 minutos e aos 30 muinutos os cäes estavam acordados e em tentativa de deambulaçäo