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2.
Anaesthesia ; 72(4): 496-503, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27987218

RESUMO

We studied the effects of tracheal tube cuffs filled with air, saline or alkalinised lidocaine on haemodynamic changes during tracheal extubation and postoperative laryngotracheal morbidity in children. We randomly allocated 164 children aged 3-13 years undergoing general anaesthesia to one of four groups; tracheal tube cuffs filled with air (n = 41); saline (n = 41); alkalinised lidocaine 0.5% (n = 41); or alkalinised lidocaine 1% (n = 41). Intracuff pressure was monitored and maintained below 20 cmH2 O. The mean (SD) increases in systolic blood pressure after tracheal extubation compared with before extubation were 10.9 (10.8) mmHg, 7.3 (17.7) mmHg, 4.1 (10.5) mmHg and 1.9 (9.5) mmHg in the air, saline, 0.5% and 1% alkalinised lidocaine groups, respectively (p = 0.021). The mean (SD) increases in diastolic blood pressure after tracheal extubation compared with before extubation were 3.9 (9.7) mmHg, 7.9 (14.6) mmHg, 0.7 (10.4) mmHg and 3.6 (6.9) mmHg in the air, saline, 0.5% and 1% alkalinised lidocaine groups, respectively (p = 0.019). The mean (SD) increases in heart rate after tracheal extubation compared with before extubation were 14.2 (7.6) beats.min-1 , 15.5 (13.1) beats.min-1 , 5.2 (9.6) beats.min-1 and 4.1 (6.6) beats.min-1 in the air, saline, 0.5% and 1% alkalinised lidocaine groups, respectively (p < 0.001). The incidence of sore throat 8 h after tracheal extubation was 22.0% in the air-filled group, 9.8% in the saline group, 4.9% in the 0.5% alkalinised lidocaine group and 2.4% in the 1% alkalinised lidocaine group, p = 0.015. We conclude that filling the tracheal tube cuff with alkalinised lidocaine-filled reduces the haemodynamic response to tracheal extubation and postoperative laryngotracheal morbidity in children.


Assuntos
Intubação Intratraqueal/efeitos adversos , Intubação Intratraqueal/métodos , Laringe/lesões , Traqueia/lesões , Adolescente , Ar , Extubação , Álcalis , Pressão Sanguínea , Criança , Pré-Escolar , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Lidocaína , Masculino , Faringite/epidemiologia , Faringite/etiologia , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/etiologia , Pressão , Estudos Prospectivos , Solução Salina
3.
J Chromatogr A ; 1427: 111-24, 2016 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-26709070

RESUMO

A systematic study on the various sources of ion suppression in UHPLC-MS-MS analysis was carried out for 24 phenolic antioxidants in 6 different extracts of medicinal plants from Amazonia. The contributions of matrix effects, mobile-phase additives, analyte co-elution and electric charge competition during ionization to the global ion suppression were evaluated. Herein, the influence of mobile-phase additives on the ionization efficiency was found to be very pronounced, where ion suppression of approximately 90% and ion enhancement effects greater than 400% could be observed. The negative effect caused by the wrong choice of internal standard (IS) on quantitative studies was also evaluated and discussed from the perspective of ion suppression. This work also shows the importance of performing studies with this approach even for very similar matrices, such as varieties of medicinal plants from the same species, because different effects were observed for the same analyte.


Assuntos
Antioxidantes/análise , Fenóis/análise , Extratos Vegetais/química , Brasil , Catequina/análogos & derivados , Catequina/análise , Cromatografia Líquida/métodos , Ácidos Cumáricos/análise , Cumarínicos/análise , Flavonoides/análise , Plantas Medicinais , Espectrometria de Massas por Ionização por Electrospray/métodos , Estilbenos/análise , Espectrometria de Massas em Tandem/métodos
4.
Anaesthesia ; 70(5): 571-6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25612162

RESUMO

We randomly allocated 129 participants with normal eyes to periconal blockade with (n = 69) or without (n = 60) ultrasound guidance before cataract surgery. There was no difference in the rates of complication, 1/69 and 0/60, respectively, p = 1.0. The rate of intraconal needle placement was 1/69 with ultrasound and 12/60 without ultrasound, a relative risk (95% CI) of 0.07 (0.01-0.55), p < 0.0001.


Assuntos
Extração de Catarata/métodos , Olho , Bloqueio Nervoso/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Anestésicos Locais/administração & dosagem , Feminino , Humanos , Injeções Intraoculares , Masculino , Erros Médicos/prevenção & controle , Erros Médicos/estatística & dados numéricos , Pessoa de Meia-Idade , Agulhas , Bloqueio Nervoso/efeitos adversos , Ultrassonografia de Intervenção , Adulto Jovem
5.
Anaesthesia ; 67(9): 980-5, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22670846

RESUMO

This study compared intubation conditions produced by the Macintosh and Airtraq™ laryngoscopes when used in obese patients in the ramped position. One hundred and thirty-two patients having bariatric surgery were placed in the ramped position and randomly assigned to have their tracheas intubated using either the Macintosh (n=64) or an Airtraq (n=68) laryngoscope. Mean (SD) intubation times were 37 (23) s and 14 (3) s for Macintosh and Airtraq, respectively (p<0.0001). Compared with the Macintosh laryngoscope, the Airtraq laryngoscope provided an improved vocal cord view as assessed by the Cormack and Lehane score (number of patients with Cormack-Lehane scores of 1/2/3/4/37/20/4/3 for the Macintosh, and 65/3/0/0 for the Airtraq laryngoscopes, p<0.0001). One patient in the Macintosh group had a failed intubation and intubation was achieved with the Airtraq. For obese patients in ramped position, Airtraq affords faster tracheal intubation than the Macintosh laryngoscope.


Assuntos
Laringoscópios , Laringoscopia/métodos , Obesidade/complicações , Adulto , Pressão Sanguínea/fisiologia , Índice de Massa Corporal , Eletrocardiografia , Feminino , Glote/anatomia & histologia , Frequência Cardíaca/fisiologia , Humanos , Hipnóticos e Sedativos , Intubação Intratraqueal , Masculino , Pescoço/anatomia & histologia , Oximetria , Oxigênio/sangue , Postura/fisiologia , Falha de Tratamento , Prega Vocal/anatomia & histologia
6.
Talanta ; 80(3): 1282-6, 2010 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-20006088

RESUMO

In this study, oil-in-water formulations were optimized to determine sodium, potassium, calcium, magnesium, zinc, and iron in emulsified egg samples by flame atomic absorption spectrometry (FAAS). This method is simpler and requires fewer reagents when compared with other sample pre-treatment procedures and allows the calibration to be carried out using aqueous standards. Different oily phases such as corn oil, decyl oleate and octyl stearate were tested, as well as Tween 80, Triton X-100 and Triton 114 were analyzed as surfactants. The optimum type and proportion of formulations were determined and their use depended on the element studied. The emulsion preparation was performed by a conventional method that involves mixing both phases at 60 degrees C by magnetic stirring and phase inversion to change the water-to-oil ratio by increasing the volume of the surfactant-water external phase and correspondingly decreasing the volume of internal phase. The accuracy of the method was further confirmed by determining the metals in a whole egg powder CRM and recoveries ranged from 97.5% for Mg to 102.2% for Na, with relative standard deviations lower than 2.3%. The precision of the procedures was determined through repeatability (intra-day precision) and intermediate precision (inter-day). The repeatability presented RSD values lower than 4.2%. The intermediate precision was evaluated using the RSD and F-test. The RSD values to intermediate precision was lower than 5.3% and the computed F-values were lower than tabulated F-values, indicating no significant difference between the results obtained on different days. The proposed method including, sample emulsification for subsequent metal determination for FAAS, has proved to be sensitive, reproducible, simple and economical.


Assuntos
Ovos/análise , Análise de Alimentos/métodos , Metais/análise , Metais/química , Métodos Analíticos de Preparação de Amostras , Animais , Cálcio/análise , Cálcio/química , Calibragem , Galinhas , Emulsões , Análise de Alimentos/normas , Ferro/análise , Ferro/química , Magnésio/análise , Magnésio/química , Potássio/análise , Potássio/química , Padrões de Referência , Reprodutibilidade dos Testes , Sódio/análise , Sódio/química , Espectrofotometria Atômica , Zinco/análise , Zinco/química
7.
Br J Anaesth ; 96(5): 569-75, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16565228

RESUMO

BACKGROUND: Little information exists regarding factors influencing perioperative cardiac arrests and their outcome. This survey evaluated the incidence, causes and outcome of perioperative cardiac arrests in a Brazilian tertiary general teaching hospital between April 1996 and March 2005. METHODS: The incidence of cardiac arrest during anaesthesia was prospectively identified from an anaesthesia database. There were 53,718 anaesthetics during the study period. Data collected included patient characteristics, surgical procedures (elective, urgent or emergency), ASA physical status classification, anaesthesia provider information, type of surgery, surgical areas and outcome. All cardiac arrests were retrospectively reviewed and grouped by cause of arrest and death into one of four groups: totally anaesthesia related, partially anaesthesia related, totally surgery related or totally patient disease or condition related. RESULTS: One hundred and eighty-six cardiac arrests (34.6:10,000) and 118 deaths (21.97:10,000) were found. Major risk factors for cardiac arrest were neonates, children under 1 yr and the elderly (P<0.05), male patients with ASA III or poorer physical status (P<0.05), in emergency surgery (P<0.05) and under general anaesthesia (P<0.05). Patient disease/condition was the major cause of cardiac arrest or death (P<0.05). There were 18 anaesthesia-related cardiac arrests (3.35:10,000) -- 10 totally attributed (1.86:10,000) and 8 partially related to anaesthesia (1.49:10,000). There were 6 anaesthesia-related deaths (1.12:10,000) -- 3 totally attributable and 3 partially related to anaesthesia (0.56:10,000 in both cases). The main causes of anaesthesia-related cardiac arrest were respiratory events (55.5%) and medication-related events (44.5%). CONCLUSIONS: Perioperative cardiac arrests were relatively higher in neonates, infants, the elderly and in males with severe underlying disease and under emergency surgery. All anaesthesia-related cardiac arrests were related to airway management and medication administration which is important for prevention strategies.


Assuntos
Anestesia/efeitos adversos , Parada Cardíaca/etiologia , Complicações Intraoperatórias , Adolescente , Adulto , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Anestesia Geral/efeitos adversos , Brasil/epidemiologia , Causas de Morte , Criança , Pré-Escolar , Emergências , Métodos Epidemiológicos , Feminino , Indicadores Básicos de Saúde , Parada Cardíaca/epidemiologia , Hospitais de Ensino , Humanos , Lactente , Recém-Nascido , Complicações Intraoperatórias/epidemiologia , Masculino , Pessoa de Meia-Idade , Distribuição por Sexo
8.
Amino Acids ; 27(1): 75-83, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15309574

RESUMO

The interaction of aluminium with some amino acids present in human blood was studied combining ion-chromatography (IC), atomic absorption spectrometry (AAS) and ultrafiltration (UF) techniques. An IC system for simultaneous determination of ornithine, lysine, glutamic acid, aspartic acid and tyrosine was developed. By adding aluminium to standard solutions of the amino acids and keeping the pH at 6 and 7 it was possible to verify that aluminium caused a reduction on the amino acid chromatographic signals. Similar experiment, carried out for copper showed the same behaviour (with different percentage of signal reductions) and validated the results for aluminium, considering that the interaction Cu-amino acid is well-established. The AAS analysis of sample fractions (500 microl) after the IC separation showed that aluminium (as copper as well) is not present in the fractions in which the amino acid peaks appear in the chromatogram. These approaches carried out with serum samples after UF showed that part of the "free" fraction of serum aluminium is distributed, besides other ligands, among these amino acids. It was found that in serum the affinity for aluminium followed the sequence Lys>Orn>Tyr>Glu approximately Asp.


Assuntos
Alumínio/química , Aminoácidos/sangue , Aminoácidos/química , Ácido Aspártico/química , Cromatografia , Cromatografia Líquida de Alta Pressão , Cromatografia por Troca Iônica , Cobre/química , Filtração , Ácido Glutâmico/química , Humanos , Concentração de Íons de Hidrogênio , Íons , Ligantes , Lisina/química , Metais/química , Ornitina/química , Espectrofotometria Atômica , Tirosina/química , o-Ftalaldeído/química
9.
J Pharm Biomed Anal ; 26(5-6): 811-8, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11600292

RESUMO

The interference of the saline concentration of fluids for peritoneal dialysis and concentrates for hemodialysis on the Limulus amebocyte lysate (LAL) assay for endotoxins was investigated. The experiments were carried out individually with each substance that compose fluids for hemodialysis, to determine the possible inhibition or enhancement effects that they could cause on the LAL assay. The compositions were also assayed to investigate the possibility of synergistic effect. They were assayed by the gel-clot method from two different suppliers, and the samples that showed inhibition effect were also assayed by the chromogenic method. The samples were analysed at successive dilutions, with different LAL sensitivities, to satisfy the endotoxin limits of 5 EU/ml for the concentrate and 0.25 EU/ml for the fluid for dialysis peritoneal. The results showed that the major interference on the gel-clot assay occurs in presence of acetic acid and in concentrates containing acid acetic, even the pH being adjusted between 6.5 and 7.5. However, the test, after an adequate dilution, could be validating for all samples. Chromogenic test can be used for peritoneal dialysis fluids considering a limit of 0.25 EU/ml and sample dilution of eight times, but it cannot be used for concentrates for hemodialysis without further dilution. Considering the results and that the chromogenic is a more time-consuming method, endotoxins in fluids for hemodialysis can be satisfactorily assayed by the gel-clot method.


Assuntos
Soluções para Diálise/análise , Endotoxinas/análise , Teste do Limulus , Diálise Renal , Géis/análise , Concentração de Íons de Hidrogênio , Indicadores e Reagentes , Diálise Peritoneal , Padrões de Referência , Sais/análise
10.
Fresenius J Anal Chem ; 370(1): 92-6, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11393244

RESUMO

A method has been developed for the chromatographic determination of methanethiol (MT) and ethanethiol (ET) as contaminants in amino acid parenteral nutrition (PN) solutions. The clean-up of the samples before chromatographic analysis was investigated by solid-phase extraction (SPE) on pre-columns filled with polyethylene powder (PE), aluminium oxide (AlOx), silica (SiOx), or polyurethane foam (PUF) as adsorbents. The thiols were more efficiently separated from the matrices by SPE on PUF pre-columns. Simultaneous derivatization and elution with DTNB (5,5'-dithiobis(2-nitrobenzoic acid)) enabled further discrimination between MT and ET by reversed-phase HPLC with spectrophotometric detection. The retention times for the derivatized MT and ET species were 12.5 and 23.0 min, respectively. Recoveries from spiked PN samples were calculated to be approximately 90%, and the MT and ET content of commercial PN solutions was determined using the methodology described. Detection limits of 15 and 10 microg L(-1) were calculated for MT and ET, respectively.


Assuntos
Aminoácidos/química , Cromatografia Líquida de Alta Pressão , Nutrição Parenteral/normas , Compostos de Sulfidrila/análise , Óxido de Alumínio/química , Ácido Ditionitrobenzoico/química , Óxidos/química , Polietileno/química , Poliuretanos/química , Compostos de Silício/química
11.
Mutat Res ; 476(1-2): 109-21, 2001 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-11336988

RESUMO

Among various environmental genotoxins, ionizing radiation has received special attention because of its mutagenic, carcinogenic and teratogenic potential. In this context and considering the scarcity of literature data, the objective of the present study was to evaluate the effect of 90Sr beta-radiation on human cells. Blood cells from five healthy donors were irradiated in vitro with doses of 0.2-5.0Gy from a 90Sr source (0.2Gy/min) and processed for chromosome aberration analysis and for comet assay. The cytogenetic results showed that the most frequently found aberration types were acentric fragments, double minutes and dicentrics. The alpha and beta coefficients of the linear-quadratic model, that best fitted the data obtained, showed that 90Sr beta-radiation was less efficient in inducing chromosome aberrations than other types of low linear energy transfer (LET) radiation such as 3H beta-particles, 60Co gamma-rays, 137Cs and 192Ir and X-rays. Apparently, 90Sr beta-radiation in the dose range investigated had no effect on the modal chromosome number of irradiated cells or on cell cycle kinetics. Concerning the comet assay, there was an increase in DNA migration as a function of radiation dose as evaluated by an image analysis system (tail moment) or by visual classification (DNA damage). The dose-response relation adequately fitted the non-linear regression model. In contrast to the cytogenetic data, 90Sr beta-radiation induced more DNA damage than 60Co gamma-radiation when the material was analyzed immediately after exposures. A possible influence of selective death of cells damaged by radiation was suggested.


Assuntos
Partículas beta/efeitos adversos , Células Sanguíneas/efeitos da radiação , Aberrações Cromossômicas , Dano ao DNA , Radioisótopos de Estrôncio/toxicidade , Adulto , Radioisótopos de Cobalto/toxicidade , Ensaio Cometa , Análise Mutacional de DNA , Feminino , Raios gama/efeitos adversos , Humanos , Técnicas In Vitro , Mutação
12.
J Chromatogr B Biomed Sci Appl ; 750(1): 61-9, 2001 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-11204224

RESUMO

Deproteinization of human serum was carried out on-line using a polyethylene powder cartridge as pre-column. The serum sample, after dilution, was injected into the chromatograph, and when passing through the cartridge the proteins were adsorbed by the polyethylene. A protein-free eluate was carried to the analytical column while the pre-column was washed with methanol and water to elute the adsorbed proteins by changing the pump channels. After washing, the pre-column was conditioned with the eluent to receive the next sample. Deproteinization was evaluated off- and on-line using pooled serum, and testing the protein residue after passing through a polyethylene cartridge with the Comassie Brilliant Blue reaction. Parameters such as serum volume, eluent and washing solution were investigated. Sodium, potassium, magnesium and calcium determinations were performed by high-performance liquid chromatography with conductimetric detection. The proposed method is suitable for the determination of these cations in serum samples without further treatments. The total analysis time was about 20 min and a linear range from 0.3 to 1.2 mg/l for sodium, potassium, magnesium and calcium was observed. The method was characterized by a precision of about 95% and recoveries from spiked samples were between 96 and 102%. The results for serum samples analysed by the proposed method were compared with photometry and atomic absorption spectrometry.


Assuntos
Cálcio/sangue , Cromatografia Líquida de Alta Pressão/métodos , Magnésio/sangue , Polietileno/química , Potássio/sangue , Proteínas/química , Sódio/sangue , Adsorção , Pós
13.
J Trace Elem Med Biol ; 15(2-3): 103-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11787973

RESUMO

The presence of aluminium in amino acids parenteral nutrition solutions can be related to the affinity of the amino acids for aluminium present in glass containers used for storage. For this study solutions of 19 amino acids used in parenteral nutrition were stored individually in glass flasks and the aluminium measured at determined time intervals. Solutions of complexing agents for aluminium, as ethylene-diaminetetraacetic acid, nitrilotriacetic acid, citrate, oxalate and fluoride ions were also stored in the same flasks and the aluminium measured during the same time interval. The measurements were made by electrothermal atomic absorption spectrometry. The aluminium content of the glass containers was also measured. The results showed that the glasses have from 0.6% to 0.8% Al. Only solutions of cysteine, cystine, aspartic acid and glutamic acid became contaminated by aluminium. As the same occurred with the complexing agents, aluminum can be released from glass due to an affinity of the substances for aluminium. Comparing the action of complexing agents and amino acids for which the stability constants of aluminium complex are known, it is possible to relate the magnitude of the stability constant with the aluminium leached from glass, the higher the stability constant, the higher the aluminium released. The analysis of commercial formulations with and without cysteine, cystine, glutamic acid or aspartic acid stored in glass containers confirms that the presence of these amino acids combined with the age of the soLution are, at least partially, responsible for the aluminium contamination. The resuLts demonstrated that the contamination is an ongoing process due to the presence of aluminium in glass combined with the affinity of some amino acids for this element.


Assuntos
Alumínio/análise , Aminoácidos/química , Contaminação de Medicamentos , Vidro , Nutrição Parenteral , Alumínio/química , Embalagem de Medicamentos , Concentração de Íons de Hidrogênio , Polietileno/química , Espectrofotometria Atômica , Fatores de Tempo
14.
J Trace Elem Med Biol ; 15(2-3): 95-101, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11787994

RESUMO

The presence of aluminium (Al) in pharmaceutical products used parenterally as sodium and potassium chlorides, glucose, heparin and albumin were investigated with respect to their storage in glass containers. As glasses can have aluminium in their composition, the aluminium may be released from the glass into the solution. The action of the substances above mentioned were investigated storing their solutions in glass and plastic containers, and measuring the aluminium in solution at determined time intervals. The aluminium present in the commercial pharmaceutical products, stored in both plastic and glass containers were also measured. All glass containers were analysed to determine their aluminium content. The aluminium determinations were done by atomic absorption spectrometry. The resuLts showed that aluminium is present in all analysed glasses in a percentage of 0.6 to 3%. Although all substances already have a residual aluminium contamination, the major contribution comes from the glass containers in which their solutions were stored. The contamination arising from glass depends too much on the nature of the substance. While the salts extracted about 400 microg Al/l in 60 days, glucose extracted 150 microg Al/l, and albumin and heparin about 500 microg Al/l in the same time interval. Commercial solutions of glucose contain about 10 microg Al/l when stored in polyethylene and from 350 to 1,000 microg Al/l when in glass ampules. Considering all commercial products, solutions stored in plastic containers contained no more than 20 microg Al/l whereas in glass the aluminium contamination reached 1,000 microg/l, and in all of them the aluminium increases with the age of the product.


Assuntos
Albuminas/análise , Alumínio/análise , Contaminação de Medicamentos , Vidro , Glucose/análise , Heparina/análise , Sais/farmacologia , Alumínio/química , Embalagem de Medicamentos , Polietileno/química , Cloreto de Potássio/química , Cloreto de Sódio/química , Espectrofotometria Atômica , Fatores de Tempo
15.
Toxicol Lett ; 117(1-2): 45-52, 2000 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-11033232

RESUMO

The objective of this study was to investigate aluminum deposition in whole blood and plasma of mice and the activity of blood delta-aminolevulinic acid dehydratase (ALA-D) after in vitro and in vivo exposure to this element. In vitro experiments showed activation and inhibition of the enzyme activity when 0.01-5.0 mM of aluminum sulphate were used (IC(50): 1.31 mM). Treatment with citrate and aluminum plus citrate increased ALA-D activity in vivo and the increase in enzyme activity was parallel to the increase in aluminum content in blood and plasma. These results show that aluminum has a distinct effect on ALA-D activity: first, at relatively lower concentrations it activated, and at high concentration it inhibited, blood ALA-D in vitro; second, it activated the enzyme when administered to drinking water. One important toxicological finding of the present report is that the apparent irrelevant addition of citrate to the drinking water significantly increased the level of aluminum in blood and plasma. Thus, in order to predict more accurately the extent of human exposure to aluminum it would be advantageous to consider the level of citrate ingestion and not exclusively the aluminum level in water or food.


Assuntos
Compostos de Alúmen/farmacologia , Sintase do Porfobilinogênio/antagonistas & inibidores , Administração Oral , Animais , Cloretos/farmacologia , Relação Dose-Resposta a Droga , Feminino , Masculino , Camundongos , Sintase do Porfobilinogênio/sangue , Sintase do Porfobilinogênio/metabolismo , Compostos de Zinco/farmacologia
16.
Talanta ; 52(6): 1047-54, 2000 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-18968066

RESUMO

A method for the simultaneous voltammetric determination of free sulfide and volatile alkythiols (methanethiol/ethanethiol) existing as contaminant in parenteral nutrition (PN) solutions was developed. The volatile sulfides (dihydrogensulfide and alkylthiols) formed in the formulations were distilled over 45 min at 47 degrees C in a purpose-made Conway cell. The analytes were quantified by differential pulse cathodic stripping voltametry (DPCSV) at the hanging mercury-drop electrode and determined, simultaneously as dihydrogensulfide and alkylthiols using a 60 s preconcentration time at -300 mV (versus Ag/AgCl, Cl(-) 3.0 mol l(-1)). The voltammetric signals were directly linear proportional to the sulfides concentrations in the PN solutions in the range 3-20 mumol l(-1) and detection limits of about 2 mumol l(-1) were calculated. Recoveries of sulfides from PN solutions in the range 90-110% were calculated using the method and nine commercial PN formulations were analyzed. Methanethiol and ethanethiol were quantified from their composite signals, and the mutual influence of the analytes on the DPCSV measurements is discussed.

17.
J Agric Food Chem ; 47(1): 212-6, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-10563874

RESUMO

The sample decomposition of the carbon disulfide evolution method for the determination of dithiocarbamate residues was carried out in a closed vial in the presence of hexane. The evolved carbon disulfide was extracted by the organic solvent and injected in a flow system for its quantification as copper complex. The conditions for batch decomposition, flow injection determination, and association of both were investigated with sodium diethyldithiocarbamate as model substance. An one-channel flow system was employed where the carrier stream was the ethanolic ethylenediamine/copper solution. The determination range was of 0. 01-1.26 microg of CS(2), with a relative standard deviation of 0.06% (n = 10), with a sample throughput of 45 samples/h. The association of the batch decomposition with the flow system was carried out with the fungicide mancozeb and was applied to the analysis of its residue in potato, lettuce, cucumber, and green bean crops. The approach allowed the analysis of 11 samples in triplicate in 2 h, with recoveries between 85% and 92% and relative standard deviation about 2%.


Assuntos
Dissulfeto de Carbono/química , Análise de Injeção de Fluxo/métodos , Fungicidas Industriais/análise , Maneb/análise , Resíduos de Praguicidas/análise , Zineb/análise
18.
Talanta ; 48(2): 341-6, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18967471

RESUMO

A method for the polarographic determination of cyanide as contaminant in pralidoxime mesylate (PM) formulations was developed. The volatile cyanide formed in the formulations was stabilized as tetracyanonickelate (TCN) anion complex after reaction with ammoniacal Ni(II) solution. The stable TCN anion complex (K(stb)=10(31)) was determined by anodic stripping voltammetry at the hanging mercury drop electrode (HMDE). The polarographic signal was proportional to the cyanide concentration and the high concentration of PM did not interfere. The linear range of calibration was from 1.2 to 16 mug cyanide with r=0.998. The RSD was 1.3% (n=5) for 2.4 mug cyanide and a detection limit of 0.8 mug cyanide was calculated. The proposed method is adequate as a quality control of PM formulations.

19.
Analyst ; 123(5): 1151-4, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9709498

RESUMO

The report describes a method for the automated polarographic determination of cyanide as tetracyanonickelate (II) anion complex in a gas-diffusion flow system. The volatile cyanide, existing in whole blood, plasma and urine samples, was measured after gas-diffusion using 8 x 10-5 mol l-1 hexaaminenickel solution as acceptor. The linear range of calibration, for measurements at the hanging mercury-drop electrode (HMDE), was from 0.1 to 2.0 micrograms cyanide with r = 0.998. The RSD was, respectively, 3.4 and 1.2% (n = 5) for 0.4 microgram cyanide measured with and without the flow-system configuration. Detection limits of 7.4 microgram l-1 were calculated using the flow system and the method was compared with the classical method using Cavet flasks. Parameters that affect the cyanide determination in the proposed method, such as acceptor solution, pH, flow rate and temperature, were investigated.


Assuntos
Cianetos/análise , Cianetos/sangue , Cianetos/urina , Humanos , Polarografia
20.
Reg Anesth Pain Med ; 23(2): 219-22, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9570615

RESUMO

BACKGROUND AND OBJECTIVES: A combination of epidural and general anesthesia has been widely used to attenuate the surgical stress response and to provide postoperative analgesia. This case report illustrates the use of this anesthetic technique. Analgesia was induced with local anesthetic in the immediate postoperative period using unintentional 19.1% potassium chloride (KCl) as diluent. METHODS: An ASA I male patient was scheduled for surgical correction of idiopathic megaesophagus under continuous epidural anesthesia combined with general anesthesia. In the postoperative period, while preparing 10 mL 0.125% bupivacaine to be administered through the epidural catheter for pain control, 5 mL 19.1% KCl was unintentionally used as diluent, resulting in a 9.55% potassium solution concentration. RESULTS: The patient developed warmness of the lower limbs, tachycardia, hypertension, intense pruritus on the chest, agitation, exacerbation of sensory and motor blocks, and respiratory failure secondary to pulmonary edema, requiring ventilatory support. Total recovery was observed after 24 hours. CONCLUSIONS: Epidurally injected potassium leads to severe clinical manifestations caused by autonomic dysfunction, spinal cord irritation, and possible release of histamine. Despite continuous recommendations, ampule misidentification still happens in hospitals, frequently leading to serious accidents.


Assuntos
Cloreto de Potássio/administração & dosagem , Cloreto de Potássio/efeitos adversos , Prurido/induzido quimicamente , Insuficiência Respiratória/induzido quimicamente , Sistema Nervoso Simpático/efeitos dos fármacos , Sistema Nervoso Simpático/fisiopatologia , Adulto , Anestesia Epidural , Anestesia Geral , Humanos , Injeções Epidurais , Masculino
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