The effect of epinephrine for the treatment of spinal-hypotension: comparison with norepinephrine and phenylephrine, clinical trial / O efeito de epinefrina, norepinefrina e fenilefrina no tratamento da hipotensão pós-raquianestesia: estudo clínico comparativo

Abstract Background and objectives: Limited data are present on safety and efficiency of epinephrine for the prophylaxis and treatment of spinal-hypotension. This study was conducted to compare the effect of epinephrine with norepinephrine and phenylephrine on the treatment of spinal-hypotension and ephedrine requirement during cesarean delivery. Methods: One hundred and sixty parturients with uncomplicated pregnancies undergoing elective cesarean delivery under spinal anesthesia were recruited. They were allocated randomly to receive norepinephrine 5 µg.mL−1 (n = 40), epinephrine 5 µg.mL−1 (n = 40), phenylephrine 100 µg.mL−1 (n = 40) or 0.9% saline infusions (n = 40) immediately after induction of spinal anesthesia. Whenever systolic blood pressure drops to less than 80% of baseline, 5 mg of intravenous ephedrine was administered as rescue vasopressor. The incidence of hypotension, total number of hypotension episodes, the number of patients requiring ephedrine, the mean amount of ephedrine consumption and side effects were recorded. Results: There was no statistically significant difference in incidence of maternal hypotension between groups. The number of patients requiring ephedrine was significantly greater in group saline than in group phenylephrine (p< 0.001). However, it was similar between phenylephrine, norepinephrine, and epinephrine groups. The mean ephedrine consumption was significantly higher in group saline than in norepinephrine, epinephrine, phenylephrine groups (p= 0.001). Conclusion: There is no statistically significant difference in incidence of hypotension and ephedrine consumption during spinal anesthesia for cesarean delivery with the use of epinephrine when compared to norepinephrine or phenylephrine. Epinephrine can be considered an alternative agent for management of spinal hypotension.

Resumo Justificativa e objetivos: Existem dados limitados sobre segurança e eficiência da epinefrina na profilaxia e tratamento da hipotensão arterial associada à raquianestesia. O presente estudo foi realizado para comparar o efeito da epinefrina com norepinefrina e fenilefrina no tratamento da hipotensão após raquianestesia e necessidade de efedrina durante o parto cesáreo. Método: Foram recrutadas 160 parturientes com gestações não complicadas, submetidas a cesariana eletiva sob raquianestesia. Elas foram alocadas aleatoriamente para receber norepinefrina 5 µg.mL-1 (n = 40), epinefrina 5 µg.mL-1 (n = 40), fenilefrina 100 µg.mL-1 (n = 40) ou infusão de solução fisiológica NaCl a 0,9% (n = 40) imediatamente após a indução da raquianestesia. Sempre que houvesse redução da pressão arterial sistólica para valor inferior a 80% da linha de base, 5 mg de efedrina iv eram administrados como vasopressor de resgate. A incidência de hipotensão, o número total de episódios de hipotensão, o número de pacientes que necessitaram de efedrina, o consumo médio de efedrina e os efeitos colaterais foram registrados. Resultados: Não houve diferença estatisticamente significante na incidência de hipotensão materna entre os grupos. O número de pacientes que necessitaram de efedrina foi significantemente maior no grupo solução fisiológica do que no grupo fenilefrina (p< 0,001). No entanto, foi semelhante entre os grupos fenilefrina, norepinefrina e epinefrina. O consumo médio de efedrina foi significantemente maior no grupo solução fisiológica do que nos grupos norepinefrina, epinefrina e fenilefrina (p = 0,001). Conclusão: Não houve diferença estatisticamente significante na incidência de hipotensão e consumo de efedrina durante raquianestesia para parto cesáreo com uso de epinefrina quando comparada à norepinefrina ou fenilefrina. A epinefrina pode ser considerada como agente alternativo para o tratamento da hipotensão após raquianestesia.

Midriáticos intracamerales en la cirugía de catarata / Intracameral mydriatics in cataract surgery

RESUMEN Durante la cirugía de catarata, la inducción de la dilatación de la pupila (midriasis) y el mantenimiento de un grado adecuado de esta a lo largo de toda la operación son elementos críticos para la eliminación y el reemplazo exitoso del cristalino. Una pupila pequeña o un cierre pupilar durante la cirugía hacen que esta sea un desafío desde el punto de vista técnico y aumente el riesgo de complicaciones transquirúrgicas, por lo que una midriasis adecuada y mantenida ha permanecido hasta nuestros días como un pilar fundamental para maximizar la seguridad y los resultados refractivos de la cirugía de catarata moderna. Esta midriasis se consigue habitualmente con la aplicación previa de colirios anticolinérgicos y simpaticomiméticos, con los cuales el tiempo de espera para la dilatación pupilar es frecuentemente más largo que el procedimiento quirúrgico; tienen una significativa absorción sistémica que pueden aumentar el riesgo de efectos secundarios cardiovasculares, y el efecto midriático tiende a desaparecer durante la cirugía. Con el objetivo de acceder a la información actualizada sobre los fármacos midriáticos más usados de modo intracameral, sus dosis y formas de aplicación durante la cirugía de catarata, se realiza el presente trabajo de revisión(AU)

ABSTRACT In cataract surgery, induction and maintenance of an adequate degree of pupil dilation (mydriasis) throughout the operation are critical elements for the successful removal and replacement of the crystalline lens. A small pupil or pupil closure during surgery pose a technical challenge and increase the risk of intraoperative complications. This is the reason why adequate, maintained mydriasis has remained to this day a fundamental pillar to maximize both safety and satisfactory refractive results in modern cataract surgery. Mydriasis is normally achieved with the previous application of anticholinergic and sympathomimetic eye drops, for which the waiting time for pupil dilation is often longer than the surgical procedure, they have significant systemic absorption which may increase the risk of cardiovascular side effects, and the mydriatic effect tends to vanish during surgery. A bibliographic review was conducted with the purpose of accessing updated information about the most commonly used intracameral mydriatic drugs, their doses and modes of application during cataract surgery(AU)

Palpebral position interdependence in blepharoptosis: comparison of the effect of instillation of 10% phenylephrine drop and digital lifting / Interdependência na posição palpebral em ptose palpebral: comparação do efeito de instilação de colírio de fenilefrina 10% e o teste de elevação digital da pálpebra

Purpose: To quantify and compare the effects of instillation with 10% phenylephrine and digital lifting on the contralateral upper eyelid of patients with involutional bilateral blepharoptosis. Methods: The present prospective clinical study involved patients with involutional bilateral blepharoptosis who underwent two tests: 1) digital lifting of the more ptotic eyelid and observation of the effect on the contralateral eyelid and 2) instillation of two drops of 10% phenylephrine in the more ptotic eye and observation of the effect on the contralateral eyelid. Patients were filmed before and 5, 10, and 15 min after instillation, and the resulting images were analyzed to obtain eyelid measurements. The results were tested using a linear mixed-effects model. Results: A total of 27 patients, ranging from 52 to 82 years of age (mean age 68.51 ± 8.21 years), 24 (88.88%) of whom were women, were included in the present study. In eyes that received instillation, the marginal distance reflex-1 (MDR1) values increased from baseline (1.21 ± 0.60 mm) until 10 min after instillation, then remained statistically unchanged until 15 min after instillation (2.42 ± 0.90 mm). Significant differences were observed in the contralateral eye of the group that underwent digital lifting (1.51 ± 0.53 mm - 1.63 ± 0.56 mm) and in the contralateral eye of the group that underwent 10% phenylephrine instillation (1.38 ± 0.54 mm - 1.63 ± 0.56 mm); p=0.02 and p<0.01, respectively. Conclusion: In all eyes, 10% phenylephrine elevated the upper eyelid, with improved eyelid height at 10 min after instillation. Significant differences were observed in the height of the contralateral eyelid when compared before and after each intervention in each group; however, this difference was very small and nearly undetectable by conventional clinical evaluation in the digital lifting group. However, the 10% phenylephrine eye-drop test resulted in substantial changes in MDR1 values ...

Objetivo: Quantificar e comparar o efeito da instilação do colírio de fenilefrina 10% com o levantamento manual da pálpebra superior contralateral de pacientes com ptose palpebral bilateral involucional. Métodos: Estudo clínico e prospectivo de pacientes com ptose palpebral bilateral involucional submetidos a dois testes: 1) elevação manual da pálpebra mais ptótica e observação do efeito da intervenção na pálpebra contralateral; e 2) a instilação de duas gotas de colírio de fenilefrina 10% no olho mais ptótico e observação do efeito da intervenção na pálpebra contralateral. Os pacientes foram filmados antes e 5, 10 e 15 minutos após a instilação. Os resultados foram analisados estatisticamente com o modelo linear de efeitos mistos. Resultados: O estudo incluiu 27 pacientes com idade entre 52-82 anos (68,51 ± 8,21), 24 dos quais eram do sexo feminino (88,88%). Em olhos submetidos a instilação do colírio, os valores da DMR1 (distância marginal reflexo) aumentaram da linha de base (1,21 ± 0,60 mm) até os 10 min, em seguida, manteve-se estatisticamente estável até 15 min (2,42 ± 0,90 mm). Diferenças significativas foram observadas nos olhos contralaterais, independentemente do levantamento manual da pálpebra (1,51 ± 0,53 mm - 1,63 ± 0,56 milímetros) e da instilação do colírio de fenilefrina 10% (1,38 ± 0,54 mm - 1,63 ± 0,56 mm), p=0,02 e p<0,01 respectivamente. Conclusões: Em todos os olhos, a instilação do colírio de fenilefrina 10% mostrou um aumento gradual do valor de distância marginal reflexo até os 10 min. Nos olhos contralaterais houve diminuição do valor de distância marginal reflexo, independentemente do teste realizado, porém as mudanças que ocorrem na posição da pálpebra contralateral, durante o teste da elevação manual, são muito pequenas e difíceis de serem detectadas no exame clínico convencional. Enquanto isso, o teste de colírio de fenilefrina 10% produziu mudanças substanciais nos valores distância marginal reflexo nos ...

Avaliação da função autonômica em portadores de cardiomiopatia hipertrófica com e sem síncope / Evaluation of the autonomic function in patients with hypertrophic cardiomyopathy with and without syncope

FUNDAMENTO: Diversos mecanismos podem estar envolvidos no desencadeamento da síncope em pacientes com cardiomiopatia hipertrófica (CMH), incluindo colapsos hemodinâmicos que podem estar relacionados a um desequilíbrio autonômico. OBJETIVO: Avaliar e comparar a função autonômica de pacientes que apresentam CMH com síncope inexplicada (SI) com os que não apresentam síncope. MÉTODOS: Trinta e sete pacientes foram incluídos, sendo 16 com SI e 21 sem síncope. Sua função autonômica foi avaliada por sensibilidade barorreflexa (SB) espontânea e induzida por fenilefrina, pela variabilidade da frequência cardíaca (VFC) no domínio do tempo durante o Holter de 24 horas e no domínio da frequência (análise espectral), ambos em decúbito dorsal e no teste de inclinação (TI) a 70º. RESULTADOS: A SB espontânea mostrou-se semelhante em ambos os grupos (16,46 ± 12,99 vs. 18,31 ± 9,88 ms/mmHg, p = 0,464), assim como a SB induzida por fenilefrina (18,33 ± 9,31 vs. 15,83 ± 15,48 ms/mmHg, p = 0,521). Não foram observadas diferenças no SDNN (137,69 ± 36,62 vs . 145,95 ± 38,07 ms, p = 0,389). O grupo com síncope apresentou um RMSSD significativamente menor (24,88 ± 10,03 vs. 35,58 ± 16,43 ms, p = 0,042) e tendência a menor pNN50 (4,51 ± 3,78 vs . 8,83 ± 7,98%, p =0,085) e a menores valores do componente de alta frequência da análise espectral da VFC em repouso (637,59 ± 1.295,53 vs. 782,65 ± 1.264,14 ms2 , p = 0,075). Nenhuma diferença significativa foi observada em resposta ao TI (p = 0,053). A sensibilidade, especificidade e acurácia do TI na identificação da etiologia da SI em pacientes com CMH foram 6%, 66% e 40%, respectivamente. CONCLUSÃO: Observou-se tônus parassimpático mais baixo em pacientes com CMH e SI, mas a relevância clínica deste achado ainda não está clara. O TI não é uma ferramenta vantajosa para avaliar a origem da síncope em tais doentes, principalmente por causa da sua baixa especificidade.

BACKGROUND: Several mechanisms may be involved in the trigger of syncope in patients with hypertrophic cardiomyopathy (HCM), including hemodynamic collapses that might be related to an autonomic imbalance. OBJECTIVE: To evaluate and compare the autonomic function of patients presenting HCM with unexplained syncope (US) to those without syncope. METHODS: Thirty-seven patients were included, 16 with US and 21 without syncope. Their autonomic function was assessed by spontaneous and phenylephrine induced baroreflex sensitivity (BRS), by heart rate variability (HRV) in time domain during 24-hour Holter and in frequency domain (spectral analysis), both in supine position and at 70º head-up tilt (HUT). RESULTS: The spontaneous BRS was similar in both groups (16,46 ± 12,99 vs. 18,31 ± 9,88 ms/mmHg, p = 0,464), as was phenylephrine-induced BRS (18,33 ± 9,31 vs. 15,83 ± 15,48 ms/mmHg, p = 0,521). No differences were observed in SDNN (137,69 ± 36,62 vs . 145,95 ± 38,07 ms, p=0,389). The group presenting syncope had a significantly lower RMSSD (24,88±10,03 vs. 35,58 ± 16,43 ms, p = 0,042) and a tendency to lower pNN50 (4,51 ± 3,78 vs . 8,83 ± 7,98%, p =0,085) and lower values of the high frequency component of HRV spectral analysis at rest (637,59±1.295,53 vs. 782,65±1.264,14ms2, p=0,075). No significant difference was observed in response to HUT (p = 0,053). HUT sensitivity, specificity and accuracy in identifying the etiology of US in HCM patients were 6%, 66% and 40%, respectively. CONCLUSIONS: A lower parasympathetic tone was observed in HCM patients with US, but the clinical relevance of this finding remains unclear. HUT is not a valuable tool for evaluating the origin of syncope in these patients, mainly because of its poor specificity.

Revisiting the impact of phenylephrine hydrochloride on static and dynamic accommodation.

Purpose: Phenylephrine hydrochloride (PHCl), a commonly used mydriatic agent, causes a small but significant deterioration of accommodation. The relative roles of pharmacology and optics in this deterioration, however, remain unascertained. The study determined the combined impact of PHCl concentration (pharmacology) and pupil size (optics) on the static and dynamic characteristics of accommodation. Materials and Methods: A total of 16 emmetropic Indian adults viewed a high-contrast visual target that switched between 67 and 33 cm viewing distance (1.5D stimulus) with their right eye (left eye occluded using infrared transmitting filter) through natural pupils and through 8, 6, 4, and 1 mm diameter artificial pupils. This protocol was repeated once without PHCl and once each with 2.5%, 5%, and 10% PHCl. Consensual accommodation of the left eye was recorded using infrared photorefraction (60 Hz). Results: Relative to no PHCl, the horizontal pupil diameter of left eye was significantly larger (P < 0.001) and the response magnitude and peak velocity of accommodation and disaccommodation were modestly but significantly smaller (P < 0.02 for all) for all concentrations of PHCl tested. There was no significant difference in these parameters across the three drug concentrations (P > 0.4 for all). The response magnitude and peak velocity also decreased significantly with pupil diameter, at similar rates for the no PHCl and the three PHCl conditions (P < 0.001 for all). Conclusion: The reduction in accommodative performance with all drug concentrations and with pupil diameter suggests independent roles of pharmacology and optics in determining accommodative performance with PHCl. The reduction in accommodative performance is, however, modest and may be clinically irrelevant in Indian eyes.

The Analysis of AC/A Ratio in Nonrefractive Accommodative Esotropia Treated with Bifocal Glasses

PURPOSE: To report the long term results of bifocal treatment in nonrefractive accommodative esotropia and to analyze the changes of accommodative convergence to accommodation (AC/A) ratio. METHODS: Sixteen patients treated with bifocal glasses for at least 5 years were evaluated retrospectively. Angle of deviation at near and distance, refractive error, and AC/A ratio by the lens gradient method were analyzed. The changes of AC/A ratios were also compared after dividing the patients according to continuation or cessation of bifocal therapy. RESULTS: Six patients (38%; bifocal stop group, BSG) were able to stop using bifocal glasses at an average age of 10.8 years (range, 6.5 to 15.4 years) during their follow-up. However, the other ten patients (62%; bifocal continue group, BCG) had to continue using bifocal glasses until the final visit, which was 13.8 years on average (range, 11.3 to 18.5 years). The AC/A ratio decreased from time of bifocal prescription to the last visit in both groups, from 4.4 to 2.7 in the BSG and from 5.9 to 4.5 in the BCG. AC/A ratios were significantly higher (p = 0.03) in the BCG than that of the BSG from the beginning of bifocal treatment and this difference was persistent until the final visit (p = 0.03). CONCLUSIONS: The AC/A ratio decreased with age in both groups but was significantly higher throughout the entire follow-up period in the BCG. AC/A ratio at bifocal prescription could be an important factor in predicting response to bifocal treatment.

Efeitos da infusão contínua profilática de fenilefrina sobre a estratégia de redução da massa de anestésico local em pacientes submetidas à raquianestesia para cesariana / Effects of prophylactic continuous infusion of phenylephrine on reducing the mass of local anesthetic in patients undergoing spinal anesthesia for cesarean section / Efectos de la infusión continua profiláctica de fenilefrina sobre la estrategia de reducción de la masa de anestésico local en pacientes sometidas a la raquianestesia para cesárea

JUSTIFICATIVA E OBJETIVOS: A redução da massa de anestésico local minimiza os efeitos da hipotensão arterial pós-raquianestesia para cesariana e a incidência de eventos adversos maternos preservando o bem-estar fetal, mas pode resultar em anestesia insuficiente. A hipotensão associada às maiores massas de anestésico subaracnóideo pode ser controlada com infusão contínua profilática de fenilefrina. Foram avaliados os efeitos da infusão contínua profilática de fenilefrina para controle pressórico sobre os resultados maternos e conceptuais em cesarianas com diferentes doses de bupivacaína hiperbárica na raquianestesia. MÉTODO: Realizou-se ensaio clínico prospectivo, não aleatório, com 60 gestantes a termo admitidas para cesariana eletiva. Alocaram-se as pacientes em dois grupos, na dependência da dose de bupivacaína hiperbárica administrada na raquianestesia, 12 ou 8 mg, acrescida de 5 µg de sufentanil e 100 µg de morfina. Realizou-se hidratação com 10 mL.kg-1 de solução lactato de Ringer antes do bloqueio. Logo após, iniciou-se infusão contínua de 100 µg.min-1 de fenilefrina, mantendo a pressão arterial nos valores basais. Avaliaram-se: nível de bloqueio anestésico, o consumo de vasopressores, incidência de eventos adversos maternos e condições do recém-nascido. RESULTADOS: Os dados maternos foram semelhantes entre os grupos quanto a: nível de bloqueio anestésico, consumo de fenilefrina por tempo, incidências de hipotensão, hipertensão, bradicardia, náuseas, vômitos, dispneia, dor e tremores. Os dados conceptuais evidenciaram semelhança entre os grupos quanto à gasometria e à dosagem de lactato nos vasos umbilicais. Todos os recém-nascidos apresentaram pH > 7,2. CONCLUSÕES: Mantendo-se a pressão arterial com infusão profilática contínua de fenilefrina, a incidência de eventos adversos maternos e as condições de nascimento conceptuais não diferem quando a raquianestesia é realizada com 12 mg ou 8 mg de bupivacaína hiperbárica.

BACKGROUND AND OBJECTIVE: Reducing the mass of local anesthetic minimizes the effects of hypotension after spinal anesthesia for cesarean section and the incidence of maternal adverse events preserving fetal well-being, but it may result in insufficient anesthesia. Hypotension associated with greater masses of subarachnoid anesthesia can be controlled by prophylactic continuous infusion of phenylephrine. The effects of prophylactic continuous infusion of phenylephrine on pressure control on maternal and fetus results in cesarean sections with different doses of hyperbaric bupivacaine in spinal anesthesia. METHODS: A non-randomized prospective study of 60 gravidas at term scheduled for elective cesarean sections was undertaken. Patients were allocated into two groups depending on hyperbaric bupivacaine dose administered for spinal anesthesia, 12 or 8 mg, along with 5 µg of sufentanil and 100 µg of morphine. Patients were hydrated with 10 mL.kg-1 of Ringer's lactate before the anesthesia. Shortly after, continuous infusion of 100 µg.min-1 of phenylephrine was initiated to maintain blood pressure at baseline levels. The following parameters were evaluated: level of anesthetic blockade, consumption of vasopressors, incidence of maternal events, and conditions of the newborn. RESULTS: Maternal data was similar in both groups regarding the level of anesthetic blockade, phenylephrine consumption along time, incidence of hypotension, hypertension, bradycardia, nausea, vomiting, dyspnea, pain, and tremors. Conceptual data showed similarities between both groups regarding blood gases and umbilical vein lactate levels. The pH of all newborns was > 7.2. CONCLUSIONS: On maintaining the blood pressure with prophylactic continuous infusion of phenylephrine the incidence of maternal adverse events and conditions of birth do not differ whether spinal anesthesia is performed with 12 mg or 8 mg of hyperbaric bupivacaine.

JUSTIFICATIVA Y OBJETIVOS: La reducción de la masa del anestésico local minimiza los efectos de la hipotensión arterial postraquianestesia para cesárea, y reduce la incidencia de eventos adversos maternos preservando el bienestar fetal, pero puede conllevar a una anestesia insuficiente. La hipotensión asociada a las mayores masas de anestésico subaracnóideo puede ser controlada con una infusión continua profiláctica de fenilefrina. Fueron evaluados los efectos de la infusión continua profiláctica de fenilefrina para el control presórico sobre los resultados maternos y conceptuales, en cesáreas con diferentes dosis de bupivacaína hiperbárica en la raquianestesia. MÉTODO: Se realizó un ensayo clínico prospectivo, no aleatorio con 60 embarazadas a término, admitidas para la cesárea electiva. Las pacientes fueron ubicadas en dos grupos, en dependencia de la dosis de bupivacaína hiperbárica administrada en la raquianestesia, 12 u 8 mg, añadida de 5 µg de sufentanil y 100 µg de morfina. Se realizó la hidratación con 10 mL.kg-1 de solución de Ringer con lactato antes del bloqueo. Inmediatamente se inició la infusión continua de 100 µg.min-1 de fenilefrina, manteniendo la presión arterial en los valores basales. Fueron evaluados: nivel de bloqueo anestésico, consumo de vasopresores, incidencia de eventos adversos maternos y condiciones del recién nacido. RESULTADOS: Los datos maternos fueron similares entre los grupos en cuanto al nivel de bloqueo anestésico, consumo de fenilefrina por tiempo, incidencias de hipotensión, bradicardia, náuseas, vómitos, disnea, dolor y temblores. Los datos conceptuales arrojaron una similitud entre los grupos en cuanto a la gasometría y a la dosificación de lactato en los vasos umbilicales. Todos los recién nacidos presentaron un pH > 7,2. CONCLUSIONES: Manteniendo la presión arterial con infusión profiláctica continua de fenilefrina, la incidencia de eventos adversos maternos y las condiciones de nacimiento conceptuales no son diferentes cuando la raquianestesia se hace con 12 mg u 8 mg de bupivacaína hiperbárica.

Utilização da fenilefrina para controle da pressão arterial em cesarianas eletivas: dose terapêutica versus profilática / Utilización de la fenilefrina para el control de la presión arterial en cesáreas electivas: dosis terapéutica versus profiláctica / Phenylephrine for blood pressure control in elective cesarean section: therapeutic versus prophylactic doses

JUSTIFICATIVA E OBJETIVOS: A anestesia raquídea é utilizada com frequência em casos de cesariana e se algumas medidas profiláticas não forem adotadas a incidência de hipotensão arterial é superior a 80 por cento. O objetivo deste estudo foi comparar a eficácia da fenilefrina quando administrada terapêutica ou profilaticamente para a manutenção da pressão arterial em pacientes submetidas à anestesia raquídea para cesarianas eletivas. MÉTODO: Foram estudadas 120 gestantes submetidas a cesarianas eletivas sob anestesia raquídea, alocadas aleatoriamente em três grupos iguais, conforme o regime de administração de fenilefrina. No Grupo 1, administrou-se fenilefrina em infusão contínua, em bomba de infusão, na dose de 0,15 µg.Kg-1.min-1 após a anestesia raquídea. No Grupo 2, foi administrada fenilefrina em dose única, de forma profilática, na dose de 50 µg após a anestesia raquídea e, no Grupo 3, fenilefrina em dose única de 50 µg em caso de hipotensão arterial definida como queda da PAS e/ou PAD de até 20 por cento em relação à média dos valores basais. Avaliou-se a incidência de hipotensão arterial, náuseas, vômitos e do índice de Apgar. RESULTADOS: A incidência de hipotensão arterial foi significativamente maior no Grupo 3, ocorrendo em 85 por cento das gestantes. Nos Grupos 1 e 2, ocorreu em 17,5 por cento e 32,5 por cento dos casos, respectivamente (p < 0,001). A incidência de náuseas foi bem superior no Grupo 3, ocorrendo em 40 por cento das pacientes, enquanto nos Grupos 1 e 2 a incidência foi de 10 por cento e 15 por cento, respectivamente, apresentando significância estatística. CONCLUSÕES: De acordo com a metodologia empregada, o estudo mostra que a infusão contínua profilática de fenilefrina iniciada imediatamente após a realização da anestesia raquídea para cesariana é mais efetiva para reduzir a incidência de hipotensão arterial e os efeitos colaterais maternos e fetais.

BACKGROUND AND OBJECTIVES: Spinal block is commonly used in cesarean sections and, if some prophylactic measures are not taken, the incidence of hypotension is higher than 80 percent. The objective of this study was to compare the efficacy of the administration of therapeutic or prophylactic doses of phenylephrine to maintain blood pressure in patients undergoing spinal block for elective cesarean section. METHODS: One hundred and twenty gravidas undergoing elective cesarean sections under spinal block, randomly divided in three equal groups according to the regimen of phenylephrine administered, were included in this study. In Group 1, continuous infusion of phenylephrine, using an infusion pump at 0.15 µg.kg-1.min-1 was administered after the spinal block. In Group 2, a single dose of prophylactic phenylephrine 50 µg was administered after the spinal block, and Group 3 received a single dose of phenylephrine 50 µg in case of hypotension, which was defined as a drop in SBP and/or DBP of up to 20 percent of baseline levels. The incidence of hypotension, nausea, and vomiting as well as the Apgar score were evaluated. RESULTS: The incidence of hypotension was significantly greater in Group 3, affecting 85 percent of the gravidas. In Groups 1 and 2 hypotension was seen in 17.5 percent and 32.5 percent of the cases respectively (p < 0.001). The incidence of nausea was much higher in Group 3 affecting 40 percent of the patients while in Groups 1 and 2 it was 10 percent and 15 percent respectively which was statistically significant. CONCLUSIONS: According to the methodology used, this study showed that prophylactic continuous infusion of phenylephrine initiated immediately after the spinal block for cesarean section is more effective in reducing the incidence of hypotension and maternal and fetal side effects.

JUSTIFICATIVA Y OBJETIVOS: La raquianestesia se usa a menudo en casos de cesárea y si algunas medidas profilácticas no se adoptan, la incidencia de hipotensión arterial es superior al 80 por ciento. El objetivo de este estudio fue comparar la eficacia de la fenilefrina cuando se administra terapéutica o profilácticamente para el mantenimiento de la presión arterial en pacientes sometidas a la raquianestesia para cesáreas electivas. MÉTODO: Se estudiaron 120 gestantes sometidas a cesáreas electivas bajo raquianestesia, ubicadas aleatoriamente en tres grupos iguales, conforme al régimen de administración de fenilefrina. En el Grupo 1, se administró fenilefrina en infusión continua, con bomba de infusión en dosis de 0,15 µg.Kg-1.min-1 después de la raquianestesia. En el Grupo 2, fue administrada fenilefrina en dosis única, de forma profiláctica, en dosis de 50 µg después de la raquianestesia, y en el Grupo 3, fenilefrina en dosis única de 50 µg en el caso de hipotensión arterial definida como una caída de la PAS y/o PAD en hasta un 20 por ciento con relación al promedio de los valores basales. Se evaluó la incidencia de hipotensión arterial, náuseas, vómitos y el índice de Apgar. RESULTADOS: La incidencia de hipotensión arterial fue significativamente más elevada en el Grupo 3, acaeciendo en un 85 por ciento de las embarazadas. En los Grupos 1 y 2, ocurrió en un 17,5 por ciento y 32,5 por ciento de los casos respectivamente (p < 0,001). La incidencia de náuseas fue bastante superior en el Grupo 3 en un 40 por ciento de las pacientes, mientras que en los Grupos 1 y 2 la incidencia fue de un 10 por ciento y un 15 por ciento respectivamente, presentando significancia estadística. CONCLUSIONES: A tono con la metodología utilizada, el estudio muestra que la infusión continua profiláctica de fenilefrina iniciada inmediatamente después de la realización de la raquianestesia para cesárea, es más efectiva en la reducción de la incidencia de hipotensión ...

Effective pupil dilatation with a mixture of 0.75% tropicamide and 2.5% phenylephrine: A randomized controlled trial.

Purpose: To compare the efficacy in pupil dilatation between a mixture containing 0.75% tropicamide and 2.5% phenylephrine and the alternate application of 1% tropicamide and 10% phenylephrine eye drops. Material and Methods: Patients requiring pupil dilatation were randomized to receive one drop of the mixture every 10 min for four times or our standard application of one drop of 1% tropicamide alternating with one drop of 10% phenylephrine every 10 min for two cycles. Pupil size was measured under bright light with the pupil gauge before, and every 5 min after initial application for 40 min. Application of the drops was discontinued once the pupil diameter reached 7 mm. Blood pressure and pulse rate were monitored every 15 min. Results: Of 40 patients (age 57.3±10.9 years, range 35-70 years), 22 were randomized into the mixture group and 18 into the alternate drug group. Baseline pupil sizes were 1.7±0.5 mm in the mixture group and 1.8±0.4 mm in the alternate drug group. The pupils were successfully dilated to 7 mm within 40 min in 17 patients of the mixture group compared to seven patients in the alternate drug group (P=0.004, Log Rank test). The mean pupil sizes at 40 min were 6.6±0.8 and 6.0±0.9 mm in the mixture and alternate drug groups respectively (P=0.050, t-test). Blood pressure and pulse rate were stable and similar in both groups. Conclusions: The mixture of 0.75% tropicamide and 2.5% phenylephrine is superior to our standard application of 1% tropicamide alternating with 10% phenylephrine. It provides faster and more successful pupil dilatation within 40 min.

The Comparison of Mydriatic Effect Between Two Drugs of Different Mechanism

PURPOSE: To maximize effective use of mydriatic drugs through comparing the pupillary dilation effects between 1% tropicamide and 2.5% phenylephrine. METHODS: Fifty people requiring pupillary dilation were divided into 3 groups. Group 1 was treated with one drop of 1% tropicamide in the right eye and one drop of 2.5% phenylephrine in the left eye. Group 2 was treated twice during a 5-minute interval with 1% tropicamide in the right eye. Group 3 was treated twice during a 5-minute interval with 2.5% phenylephrine in the right eye. Groups 2 and 3 were treated with 2.5% phenylephrine and 1% tropicamide in the left eye, administered during a 5-minute interval. The pupillary size was measured in all groups for 40 minutes following eye drops administration. RESULTS: The mean patient age was 15.7 years. Group 1 included 10 patients, and groups 2 and 3 included 20 patients each. Eight patients in group 1 and 16 patients in group 2 developed a larger right pupil. Fourteen patients in group 3 developed a larger left pupil. CONCLUSIONS: Our study showed that 1% tropicamide, with its parasympathetic antagonistic mechanism of action, was more effective at inducing pupillary dilation than 2.5% phenylephrine, and the combination of 1% tropicamide and 2.5% phenylephrine was more effective than multiple drops of single eye drops.

Ação do colírio de fenilefrina 10 por cento no posicionamento palpebral de indivíduos normais / Phenylephrine 10 percent eye drop action in the eyelid position in healthy subjects

OBJETIVOS: Determinar a ação de uma gota do colírio de fenilefrina 10 por cento sobre as pálpebras superior e inferior de indivíduos normais; verificar a ocorrência de alterações no posicionamento das pálpebras superior e inferior do olho contralateral, após instilação desta medicação. MÉTODOS: Estudo prospectivo observacional, do qual participaram 24 indivíduos normais, com idade entre 20 e 39 anos, submetidos à instilação de uma gota do colírio de fenilefrina 10 por cento no fundo de saco conjuntival superior, aleatoriamente em um dos olhos. Todos os indivíduos foram filmados antes e após a instilação do colírio (3, 10, 15, 30, 45 e 60 minutos). As imagens foram submetidas ao processamento digital e editadas para análise das medidas palpebrais. Foi traçada uma linha horizontal do canto medial até o canto externo. Considerou-se a altura da pálpebra superior a distância entre o ponto mais alto da margem palpebral superior e a linha horizontal traçada. A altura palpebral inferior foi avaliada como a distância entre o ponto mais baixo da margem palpebral inferior e a referida linha. RESULTADOS: Em relação à pálpebra superior, a medida antes da instilação da fenilefrina 10 por cento diferiu significativamente dos demais momentos (p<0,001) com elevação média da pálpebra superior de 0,79 mm e retração de 0,37 mm na altura palpebral inferior. Em relação ao olho contralateral, observou-se queda da pálpebra superior em praticamente todos os momentos estudados, com o menor nível aos 3 minutos (queda média de 0,68 mm). A pálpebra inferior contralateral mostrou elevação média de 0,37 mm. CONCLUSÕES: A instilação de uma gota do colírio de fenilefrina 10 por cento em olhos de indivíduos normais altera a posição da pálpebra superior do olho testado, assim como a da pálpebra inferior. O posicionamento da pálpebra superior e inferior do olho contralateral também se alteram.

PURPOSE: To determine the upper and lower eyelid position with a single drop of 10 percent phenylephrine in normal individuals and observe positional lid changes in upper and lower lids of the opposite eye. METHODS: Prospective observational study including 24 healthy subjects of both genders (age range: 20-39 yrs) submitted to instillation of a single drop of 10 percent phenylephrine in the upper fornix of one randomly chosen eye. A video camera recorded the images of both eyes before and after eye drop application at 3, 10, 15, 30, 45 and 60 minutes. The images were digitally processed and edited to analyze lid measurements (upper lid height: distance between the highest upper margin lid point and a horizontal line traced from the medial to the lateral canthus; lower lid height: distance between the lowest margin lid point and the above-mentioned line). RESULTS: Before and after drug instillation, upper lid height was significantly different (p<0.001) at all moments with a mean elevation of 0.79 mm. The lower lid height changed too with a mean retraction of 0.37 mm. In the fellow eye upper lid drop was observed at almost all moments with the lowest value at 3 minutes (mean reduction of 0.68 mm) and elevation (0.37 mm) of lower lid. CONCLUSIONS: This experiment showed that a single drop of 10 percent phenylephrine acted not only on the upper eyelid but also on lower lid of the tested eye. Control mechanism of lid opening and closing changed upper and lower lid positioning of the opposite eye in healthy subjects.

Control hemodinámico con fenilefrina en anestesia espinal para cirugía de rodilla / Hemodynamic control with phenylephrine in spinal anesthesia during knee surgery

Antecedentes: La anestesia espinal es utilizada en cirugías ortopédicas, pero produce hipotensión arterial en 10-40 por ciento de los pacientes. El uso de fenilefrina en infusión profiláctica ha permitido mantener la presión arterial durante el parto, pero no hay estudios en cirugías de reemplazo de rodilla. Objetivos: Evaluar el efecto de la infusión continua profiláctica de fenilefrina sobre la presión arterial sistólica (PaS), media (PaM) y diastólica (PaD), y la frecuencia cardíaca (FC) en cirugía de implante protésico de rodilla, comparado con placebo. También se evaluaron: la reposición de fluidos, los episodios de hipotensión y bradicardia, y los requerimientos de efedrina. Lugar de realización: Servicio de Anestesiología del Hospital Italiano de Buenos Aires. Diseño: Ensayo clínico, aleatorizado, controlado con placebo, doble ciego. Población: Se incluyeron 30 pacientes sometidos a reemplazo protésico de rodilla. Métodos: Se aleatorizaron al grupo F (bomba con infusión profiláctica con fenilefrina, n = 15) o al grupo P (solución fisiológica, n = 15). Se realizo bloqueo femoral y anestesia espinal. Las variables hemodinámicas se evaluaron en hora basal, inicio de infusión y a los 3, 6, 15, 30, 45 y 60 minutos posbloqueo. Resultados: No se encontró diferencia significativa entre los grupos en cuanto a PaS, PaM, PaD y FC. Tampoco en relación con el número de episodios de hipotensión, bradicardia, administración de efedrina, ni en los requerimientos de fluidos administrados. Conclusiones: En pacientes con anestesia espinal, la infusión profiláctica de fenilefrina no disminuyó la magnitud de la hipotensión posbloqueo, en comparación con placebo, durante la cirugía de implante protésico de rodilla.

Background: Spinal anesthesia is used in orthopedic surgery but it produces arterial hypotension in 10-40 per cent of patients. The use of prophylactic infusion of phenylephrine could maintain arterial pressure during cesarean delivery, but no tests were carried out during knee replacement surgery. Objective: Evaluation of the effect of prophylactic infusion of phenylephrine on systolic (SaP), diastolic (DaP), median (MaP) and cardiac rate (CR) during knee replacement surgery with spinal anesthesia, compared to with placebo. We also evaluated amount of fluids, hypotension and bradycardic episodes, and ephedrine requirements. Setting: Anesthesiology Service of Hospital Italiano de Buenos Aires. Design: clinical trial, randomized, placebo controlled, double blinded. Population: We included 30 patients scheduled for knee replacement surgery. Methods: Patients were randomized to group F (prophylactic infusion of phenylephrine, N = 15) or group P (placebo, n = 15). Hemodynamic variables were evaluated at basal, start of infusion and at 3, 6, 15, 30, 45 and 60 minutes from the blockade. Results: The differences in SaP, DaP, MaP and CR were not statistically different. Neither were the numbers of cases with hypotension, bradycardia, ephedrine requirements or fluids administered. Conclusions: In patients receiving spinal anesthesia for knee replacement surgery, a prophylactic infusion of phenylephrine did not decrease the magnitude of hypotension in comparison with placebo.

Antecedentes: A anestesia espinhal é utilizada em cirurgias ortopédicas, mas causa hipotensao arterial em 10-40 por cento dos pacientes. O uso da fenilefrina em infusao profilática permitiu manter a pressao arterial durante o parto; porém, nao se conhecem estudos sobre seu uso em cirurgias de substitução de joelho. Objetivos: Avaliar o efeito da infusao continua profilática de fenilefrina sobre a pressao arterial sistólica (PaS), média (PaM) e diastólica (PaD) e a freqüencia cardiaca (FC) em cirurgia de implante de prótese de joelho, comparado com placebo. Foram também avaliados: a reposição de fluídos, os episódios de hipotensao e bradicardia, e a necessidade de efedrina. Lugar de realização: Serviço de Anestesiologia do Hospital Italiano de Buenos Aires. Desenho: Estudo clínico, aleatorizado, controlado com placebo, duplo-cego. População: Trinta pacientes submetidos a substituiçao protésica de joelho. Métodos: Os pacientes foram aleatorizados ao grupo F (bomba de infusao profilática, fenilefrina, n = 15) ou ao grupo P (solução fisiológica, n = 15). Foi feito bloqueio 3 em 1 e anestesia espinhal. Avaliaram-se as variáveis hemodinamicas no momento basal, no inicio da infusao e aos 3, 6, 15, 30, 45 e 60 minutos pós-bloqueio. Resultados: Entre os grupos nao se encontrou diferença significativa no que diz respeito a PaS, PaM, PaO e FC, número de casos de hipotensao, de bradicardia, de administração de efedrina nem nas necessidades de fluidos administrados. Conclusoes: Em pacientes com anestesia espinhal, a infusao profilática de fenilefrina nao diminuiu a magnitude da hipotensao pós-bloqueio, em comparação com placebo, durante cirurgia de implante de prótese de joelho.

Efeito da ação tópica do colírio de fenilefrina a 10 por cento no posicionamento palpebral de indivíduos normais e portadores de blefaroptose adquirida involucional / Effect of 10 percent phenylephrine eye drops action in the eyelid position in healthy subjects and in patients with acquired involutional blepharoptosis

INTRODUÇÃO: Existem poucos estudos na literatura sobre o efeito de drogas no posicionamento vertical das pálpebras. Esse assunto é importante na análise da dinâmica palpebral, principalmente em afecções como a blefaroptose. O objetivo deste estudo é determinar a ação de uma gota do colírio de fenilefrina a 10% sobre as pálpebras superior e inferior de indivíduos normais e portadores de blefaroptose adquirida involucional e verificar a ocorrência de alterações no posicionamento das pálpebras superior e inferior do olho contralateral. MÉTODOS: Realizou-se um estudo clínico, prospectivo e aberto com indivíduos normais e pacientes com blefaroptose adquirida involucional, que foram submetidos à instilação de uma gota do colírio de fenilefrina a 10% em um dos olhos. Todos os indivíduos foram filmados antes e após a instilação da medicação (3, 10, 15, 30, 45 e 60 minutos). As imagens foram submetidas ao processamento digital e editadas para análise das medidas palpebrais. Foi traçada uma linha horizontal a partir do canto medial em direção ao canto externo. Considerouse como altura da pálpebra superior a distância entre o ponto mais alto da margem palpebral superior e a linha horizontal traçada. A altura palpebral inferior foi avaliada como a distância entre o ponto mais baixo da margem palpebral inferior e a referida linha. RESULTADOS: Foram incluídos na pesquisa 70 indivíduos normais e 40 portadores de blefaroptose adquirida involucional. Em relação à blefaroptose, a maioria apresentava quadro bilateral (92,5%) e grau mínimo (45%). Em relação à resposta ao colírio de fenilefrina a 10%, a medida antes da instilação da medicação diferiu significativamente dos demais momentos (p< 0,001), com elevação média da pálpebra superior de 0,92 mm e retração de 0,40 mm na altura palpebral inferior em todos os grupos estudados. Em relação ao olho contralateral, observou-se queda da pálpebra superior em praticamente todos os momentos estudados, com o menor nível aos...

INTRODUCTION: There are few studies in the literature on the effect of drugs on the vertical positioning of the eyelids. This issue is important in the analysis of the eyelid dynamics mainly in disorders such as blepharoptosis. The aim of this study is to determine the action of a single drop of 10% phenylephrine on the upper and lower eyelids of healthy subjects and patients with acquired involutional blepharoptosis and observe the occurrence of changes in the positioning of the upper and lower eyelids of the contralateral eye. METHOD: A prospective clinical trial was done with healthy subjects and patients with acquired involutional blepharoptosis. The patients were submitted to the instillation of a single drop of 10% phenylephrine in one eye. All subjects were filmed before and after instillation of medication (3, 10, 15, 30, 45 and 60 minutes). The images were submitted to digital processing and edited to analyze lid measurements. A horizontal line was drawn from the medial canthus toward the outer. The upper eyelid height was measured as the distance between the highest point of the upper eyelid margin and the horizontal line drawn. The lower eyelid height was the distance between the lowest point of the margin lower eyelid and the drawn line. RESULTS: Seventy healthy subjects and 40 patients with acquired involutional blepharoptosis were included. Most patients had bilateral (92,5%) and mild blepharoptosis (45%). After 10% phenylephrine instillation, upper lid height showed a mean elevation of 0,92 mm, which was significantly different at all time measurements (p< 0,001). The lower eyelid height changed with a mean retraction of 0,40 mm. In the contralateral eye was observed a fall of upper eyelid in all most all times studied, with the lowest level observed at 3 minutes (with average fall of 0,66 mm). The contralateral lower eyelid showed an average elevation of 0,35 mm. CONCLUSION: Instillation of a single drop of 10% phenylephrine altered...

Efeitos cardiovasculares e midriáticos da fenilefrina tópica a 2,5 e a 10,0 por cento em voluntários sadios / Cardiovascular and pupillary effects of topical ophthalmic 2.5 and 10.0 percent phenylephrine in healthy volunteers

OBJETIVO: Comparar os efeitos cardiovasculares e midriáticos da fenilefrina tópica nas concentrações de 2,5 e 10,0 por cento. MÉTODOS: Ensaio clínico do tipo caso controle, randomizado, com auto-emparelhamento. Foram monitoradas a freqüência cardíaca (FC), a pressão arterial (PA) e a midríase em voluntários sadios, com idade entre 18 e 45 anos, após a instilação da fenilefrina a 2,5 e a 10,0 por cento em duas ocasiões diferentes. RESULTADOS: A amostra foi constituída de 28 voluntários, sendo 17 do sexo masculino e 11 do sexo feminino, com a idade média de 26,5 anos. Não foi verificado nenhum padrão de mudanças com relação à freqüência cardíaca e à pressão arterial sistólica. Com relação à pressão arterial diastólica média dos indivíduos, não foi encontrada variação significativa após a instilação da fenilefrina a 2,5 por cento nos tempos de um, cinco, dez e 30 minutos, o que se revelou bem diferente quando do uso da fenilefrina a 10,0 por cento, com a qual houve aumento da pressão arterial diastólica média após cinco e dez minutos, e subseqüente queda após 30 minutos, porém sem significância estatística. A midríase foi maior com a fenilefrina a 10,0 por cento nos dois olhos, sendo a diferença estatisticamente significativa. CONCLUSÕES: Observou-se maior efeito midriático da fenilefrina a 10,0 por cento, quando comparada a 2,5 por cento, com significância estatística. Já com relação aos efeitos cardiovasculares não houve diferença estatística entre as duas concentrações.

PURPOSE: To compare the cardiovascular and mydriatic effects of 2.5 percent and 10.0 percent phenylephrine. METHODS: A case-control, randomized, crossover clinical trial study. We monitored heart rate (HR), blood pressure (BP) and mydriasis in healthy volunteers aged 18-45 years after the instillation of 2.5 percent and 10.0 percent phenylephrine in two different occasions. RESULTS: The sample comprised 28 healthy volunteers, 17 male and 11 female, with a mean age of 26.5 years. No changes in heart rate and systolic blood pressure were observed. No significant variation of the mean diastolic blood pressure was found after 1, 5, 10 and 30- minute instillation of 2.5 percent phenylephrine. However, with 10.0 percent phenylephrine, there was an increase in mean diastolic blood pressure after five and ten minutes, followed by a drop after 30 minutes, which was not statistically significant. Mydriasis was more marked in both eyes with a statistically significant difference after instillation of 10.0 percent phenylephrine. CONCLUSIONS: The mydriatic effect was greater with 10.0 percent phenylephrine than with 2.5 percent phenylephrine and the difference was statistically significant. No statistically significant difference was found in relation to cardiovascular effects in both phenylephrine concentrations.

Single dose of 1% tropicamide and 10% phenylephrine for pupil dilation.

OBJECTIVE: To compare the efficacy of pupil dilation between a single dose and three doses of 1% tropicamide and 10% phenylephrine for binocular indirect ophthalmoscopy. MATERIAL AND METHOD: A prospective randomized double-blind clinical controlled trial was conducted. All patients underwent the binocular indirect ophthalmoscopy and met the inclusion criteria were randomized into two groups using block randomization. Group A received a single dose of 1% tropicamide and 10% phenylephrine eye drops, and Group B received three doses of the same drugs. The primary outcome was the horizontal pupil diameter measured by slit-lamp biomicroscope (Haag-Streit model 900) before and at 10, 15, 20, 25 and 30 minutes after eye drop instillation. The clinical equivalence of the efficacy of pupil dilation between the two groups was defined as the difference of less than or equal to 1 mm (-1 mm to + 1 mm). RESULTS: Eighty patients (160 eyes) were randomized into 40 patients (80 eyes) in group A and 40 patients (80 eyes) in group B. The mean pupil sizes at baseline of group A were 3.51 +/- 0.63 mm in the right eye and 3.39 +/- 0.67 mm in the left eye. Those in group B were 3.61 +/- 0.67 mm in the right eye and 3.66 +/- 0.72 mm in the left eye. The mean pupil diameters at 30 minutes of group A were 7.34 +/- 0.51 mm in the right eye and 7.41 +/- 0.56 mm in the left eye, whereas those of group B were 7.49 +/- 0.45 mm in the right eye and 7.51 +/- 0.40 mm in the left eye. The mean difference of the pupil size between the two groups was 0.15 mm (p = 0.175) in the right eye and 0.l0 mm (p = 0.362) in the left eye. The 95% confidence intervals of the difference in pupil size were -0.36 to 0.07 mm in the right eye and -0.32 to 0.12 mm in the left eye. CONCLUSION: The 95% confidence interval of the difference in pupil size lay entirely within the range of equivalence. The single dose of 1% tropicamide and 10% phenylephrine was clinically equivalent to the three doses of the same drugs.

Derivative spectrophotometry for simulataneous analysis of chlorpheniramine maleate, phenylephrine HCI, and phenylpropanolamine HCI in ternary mixtures and pharmaceutical dosage forms

In this study, different derivative spectrophotometric methods are proposed for the simultaneous determination of chlorpheniramine maleate [CP], phenylephrine HCl [PE] and phenylpropanolamine HCl [PP] in their ternary mixtures and in pharmaceutical dosage forms. Spectra of single component and ternary mixtures of various concentrations and combinations from zero- to fourth-derivation were obtained. Also the spectra of the excipients including lactose, starch, and microcrystalline cellulose were obtained to study the possible interference from matrices. Zero-crossing derivative spectrophotometry based on recording the second-derivative curve for PE at 286.5 nm and fourth-derivative curve for PP at 220 nm were used for determining each component. Third component, CP, was determined by measuring absolute amplitudes at 265.8, 262.2, 269.5, and 273.8 nm in its second derivative spectra. Results showed that the matrices have no interferences. The calibration curves were linear in the range of 1-8 micro g/ml for PE; 5-30 micro g/ml for PP; and 2-8 micro g/ml for CP. The limits of detection were 0.2 micro g/ml for PE, 0.1 micro g/ml for PP, and 0.3 micro g/ml for CP. The mean percentage recoveries obtained for different synthetic mixtures by using this method were 95.3% with coefficient of variation of 4.3% for PE, 101.5% with coefficient of variation of 1.4% for PP, and 99.4% with coefficient of variation of 1.5% for CP. This method has been applied successfully for the determination of PE and PP in its combination with CP in Antihistamine Decongestant tablets with a high percentage of recovery, good accuracy and precision

Randomized double-blind study of phenylephrine 2.5% vs 10% on pupillary dilation.

PURPOSE: To compare the efficacy of phenylephrine 2.5% versus 10% on pupillary dilation, and also compare their side-effects. METHOD: Patients at the Eye Clinic Srinagarind Hospital were randomized into two groups. Patients in group 1 received 1% tropicamide and 10% phenylephrine, whereas those in group 2 received 1% tropicamide and 2.5% phenylephrine. Pupil diameter, blood pressure and heart rate were measured before and after eyedrop instillation. RESULTS: Five hundred and sixty four patients were randomized into 293 patients (group 1) and 271 patients (group 2), using simple random sampling method. Mean pupil diameters before instillation in group 1 were 4.43 +/- 1.13 mm in the right eye and 4.31 +/- 0.95 mm in the left eye, whereas those in group 2 were 4.45 +/- 1.0 mm in the right eye and 4.32 +/- 0.92 mm in the left eye. After the instillation, the mean pupil diameters in group 1 were 7.58 +/- 0.96 mm in the right eye and 7.60 +/- 1.03 mm in the left eye, whereas those in group 2 were 7.17 +/- 1.04 mm in the right eye and 7.07 +/- 1.06 mm in the left eye. The difference was statistically significant (P < 0.05). There was no significant difference in mean systolic and diastolic blood pressure after instillation between the two groups. However, the mean heart rate after instillation in group 1 was greater than the value in group 2 with statistically significant difference. CONCLUSION: Pupillary dilation with 1% tropicamide and 10% phenylephrine is more effective than 1% tropicamide and 2.5% phenylephrine with statistically significant difference. After single dose instillation, there was no significant difference in the mean blood pressure between the two groups.

Comparison of infusions of phenylephrine and ephedrine in spinal anaesthesia

Objectives to assess the maternal cardiovascular changes [i.e. hypotension] and neonatal status in healthy women who underwent elective C.S under epidural anaesthesia and to compare the effect of optimal doses of 3 different vasopressors on hypotension and acid-base status in mothers and neonates during spinal anaesthesia [SA] for caesarian section [CS]. the total number of pregnant women who underwent, spinal anaesthesia during c.s were 150 between Jan 1st till 31st Dec 1999 at Q.A.M.H., a total of 15 pregnant women were randomly selected into: group 1 received an infusion of ephedrine 1mg/min [at 60ml/hr]. Group 2 received an infusion of ephedrine 2mg/min [at 120ml/hr] and group 3 was given an infusion of phenylephrine 10 mcg/min [at 60ml/hr] there was no significant difference in maternal age, weight or systolic arterial pressure between the 3 groups. Similarly, there was no significant difference between the 3 groups in the volume of bupivacaine used, time taken for anaesthesia to reach T4, time from insertion of the spinal to delivery of fetus and uterine incision delivery time