Morphine and Hydromorphone Effects, Side Effects, and Variability: A Crossover Study in Human Volunteers.

BACKGROUND: Balancing between opioid analgesia and respiratory depression continues to challenge clinicians in perioperative, emergency department, and other acute care settings. Morphine and hydromorphone are postoperative analgesic standards. Nevertheless, their comparative effects and side effects, timing, and respective variabilities remain poorly understood. This study tested the hypothesis that IV morphine and hydromorphone differ in onset, magnitude, duration, and variability of analgesic and ventilatory effects. METHODS: The authors conducted a randomized crossover study in healthy volunteers. Forty-two subjects received a 2-h IV infusion of hydromorphone (0.05 mg/kg) or morphine (0.2 mg/kg) 1 to 2 weeks apart. The authors measured arterial opioid concentrations, analgesia in response to heat pain (maximally tolerated temperature, and verbal analog pain scores at discrete preset temperatures to determine half-maximum temperature effect), dark-adapted pupil diameter and miosis, end-expired carbon dioxide, and respiratory rate for 12 h after dosing. RESULTS: For morphine and hydromorphone, respectively, maximum miosis was less (3.9 [3.4 to 4.2] vs. 4.6 mm [4.0 to 5.0], P < 0.001; median and 25 to 75% quantiles) and occurred later (3.1 ± 0.9 vs. 2.3 ± 0.7 h after infusion start, P < 0.001; mean ± SD); maximum tolerated temperature was less (49 ± 2 vs. 50 ± 2°C, P < 0.001); verbal pain scores at end-infusion at the most informative stimulus (48.2°C) were 82 ± 4 and 59 ± 3 (P < 0.001); maximum end-expired CO2 was 47 (45 to 50) and 48 mmHg (46 to 51; P = 0.007) and occurred later (5.5 ± 2.8 vs. 3.0 ± 1.5 h after infusion start, P < 0.001); and respiratory nadir was 9 ± 1 and 11 ± 2 breaths/min (P < 0.001), and occurred at similar times. The area under the temperature tolerance-time curve was less for morphine (1.8 [0.0 to 4.4]) than hydromorphone (5.4°C-h [1.6 to 12.1] P < 0.001). Interindividual variability in clinical effects did not differ between opioids. CONCLUSIONS: For morphine compared to hydromorphone, analgesia and analgesia relative to respiratory depression were less, onset of miosis and respiratory depression was later, and duration of respiratory depression was longer. For each opioid, timing of the various clinical effects was not coincident. Results may enable more rational opioid selection, and suggest hydromorphone may have a better clinical profile.

Influence of miosis and laser peripheral iridotomy on intraocular lens power calculation in patients with primary angle closure disease.

OBJECTIVES: To evaluate the effect of miosis and laser peripheral iridotomy (LPI) on intraocular lens (IOL) power prediction and ocular biometry in eyes with primary angle closure disease (PACD). METHODS: In this prospective observational study, primary angle closure suspects (PACS), and subjects classified with primary angle closure (PAC)/primary angle-closure glaucoma (PACG) undergoing LPI were enrolled. Ocular biometric parameters were measured with IOLMaster700 at baseline (T0), one week after pilocarpine instillation (T1), and another week post LPI (T2). Biometric changes and the IOL power predicted for emmetropia using Barrett Universal II, Haigis, Holladay2, Hoffer Q and SRK/T formulae were analysed and compared among different time points. RESULTS: 100 eyes of 50 PACS and 50 PAC/PACG patients were enrolled. Following pilocarpine-induced miosis, lens thickness (LT) increased and anterior chamber depth (ACD) decreased (all groups p < 0.01), while white-to-white diameter decreased and central corneal thickness increased significantly only in the PACS cohort (both p < 0.01). Compared to baseline, LPI induced an increase of ACD and a slight decrease of LT in PACS (both p < 0.01), whereas only axial length changed significantly (p = 0.012) in the PAC/PACG cohort. Regardless of the formula used, no significant difference to the predicted IOL power for emmetropia existed among the three time points in each group (all p > 0.1). CONCLUSION: We report the changes of anterior segment parameters induced by miosis and LPI in PACD. These interventions do not significantly affect the IOL power calculation predicted for emmetropia in Chinese eyes when common third-, fourth-and new generation IOL formulae are used.

Topical Review: Pilocarpine-induced Miosis as Help for Early Presbyopes?

SIGNIFICANCE: The clinical utility of ophthalmic pilocarpine-induced pupil constriction to help overcome image blur of close-up targets in patients with failing accommodation is examined.Pilocarpine in low-concentration ophthalmic solution eye drops constricts the pupil to approximately 2 mm and thus reduces defocus blur. To gain regulatory approval of this drug for the treatment of presbyopia, clinical trials were conducted with 1.25% pilocarpine. Near vision was improved in a modest proportion of early presbyopes: between 12 and 22% more patients reached criterion near visual acuity than with a placebo, depending on conditions. The drug is well tolerated, and its effect has onset of only minutes and lasts several hours. Small pupils will cause diminished night vision and may have an impact on distance acuity to which possible minor drug-induced accommodative spasms could contribute. The therapy has a role for patients who want to postpone or briefly pause dioptric supplementation of their failing accommodation. No convincing case has been made for one version of ophthalmic pilocarpine over another.

Unintentional buprenorphine and methadone poisoning in children: a matched observational study.

OBJECTIVE: To compare accidental pediatric poisoning from methadone vs. buprenorphine in terms of clinical indicators and in-hospital morbidity. METHODS: A matched observational study conducted on children aged ≤12 years admitted to our center between March 2018 and March 2019 with acute poisoning from methadone or buprenorphine. Data were extracted from the electronic patient files of the pediatric methadone poisoning cases, and buprenorphine poisoning cases were followed from ED, during the study period. Cases were compared regarding rates of bradypnea/apnea (primary outcome), the need for antidote therapy and intubation, duration of hospital stay, miosis, loss of consciousness, blood gas analyses, and mortality (secondary outcomes). RESULTS: A total of 90 methadone- and 30 buprenorphine-poisoned children were evaluated. Methadone cases had significantly higher rates of apnea (20/90 methadone vs. 0/30 buprenorphine; OR = 17.7, 95% CI 1.1, 302.8; p = 0.047), but there was no group difference in bradypnea (39/90 methadone vs. 10/30 buprenorphine; p = ns). 28 (31%) methadone and 3 buprenorphine (10%) cases had been referred to as fully awake (p = 0.013). Methadone cases required higher median naloxone doses for initial bolus (0.4 vs. 0.02 mg; p = 0.014) and maintenance infusion (14.4 vs. 2.4 mg; p < 0.001). 20 apnea cases (all from the methadone group) had miotic pupils, and miotic pupils were seen in 44 (90%) cases with bradypnea (OR = 3.2, 95% CI 1.1, 9.3; p = 0.026). Intubation was needed in only 5 methadone cases (5.5%; p = ns). All patients survived. CONCLUSION: Compared to children poisoned with methadone, buprenorphine cases had higher rates of loss of consciousness on admission but subsequently experienced fewer complications during hospital treatment, which is likely due to the buprenorphine partial antagonist effect. Our findings suggest that methadone exposure is more toxic than buprenorphine in pediatric populations.

Iris stromal cell nuclei deform to more elongated shapes during pharmacologically-induced miosis and mydriasis.

Nuclear shape alteration in ocular tissues, which can be used as a metric for overall cell deformation, may also lead to changes in gene expression and protein synthesis that could affect the biomechanics of the tissue extracellular matrix. The biomechanics of iris tissue is of particular interest in the study of primary angle-closure glaucoma. As the first step towards understanding the mutual role of the biomechanics and deformation of the iris on the activity of its constituent stromal cells, we conducted an ex-vivo study in freshly excised porcine eyes. Iris deformation was achieved by activating the constituent smooth muscles of the iris. Pupillary responses were initiated by inducing miosis and mydriasis, and the irides were placed in a fixative, bisected, and sliced into thin sections in a nasal and temporal horizontal orientation. The tissue sections were stained with DAPI for nucleus, and z-stacks were acquired using confocal microscopy. Images were analyzed to determine the nuclear aspect ratio (NAR) using both three-dimensional (3D) reconstructions of the nuclear surfaces as well as projections of the same 3D reconstruction into flat two-dimensional (2D) shapes. We observed that regardless of the calculation method (i.e., one that employed 3D surface reconstructions versus one that employed 2D projected images) the NAR increased in both the miosis group and the mydriasis group. Three-dimensional quantifications showed that NAR increased from 2.52 ± 0.96 in control group to 2.80 ± 0.81 and 2.74 ± 0.94 in the mydriasis and miosis groups, respectively. Notwithstanding the relative convenience in calculating the NAR using the 2D projected images, the 3D reconstructions were found to generate more physiologically realistic values and, thus, can be used in the development of future computational models to study primary angle-closure glaucoma. Since the iris undergoes large deformations in response to ambient light, this study suggests that the iris stromal cells are subjected to a biomechanically active micro-environment during their in-vivo physiological function.

The Tokyo subway sarin attack has long-term effects on survivors: A 10-year study started 5 years after the terrorist incident.

OBJECTIVES: The Tokyo subway sarin attack in 1995 was an unprecedented act of terrorism that killed 13 people and sickened more than 6,000. The long-term somatic and psychological effects on its victims remain unknown. METHODS: We conducted analyses on the self-rating questionnaire collected annually by the Recovery Support Center (RSC) during the period from 2000 to 2009. The RSC is the only organization that has large-scale follow-up data about sarin attack victims. The prevalence of self-reported symptoms was calculated over 10 years. We also evaluated the prevalence of posttraumatic stress response (PTSR), defined as a score ≥ 25 on the Japanese-language version of the Impact of Event Scale-Revised. The multivariate Poisson regression model was applied to estimate the risk ratios of age, gender, and year factor on the prevalence of PTSR. RESULTS: Subjects were 747 survivors (12% of the total) who responded to the annual questionnaire once or more during the study period. The prevalence of somatic symptoms, especially eye symptoms, was 60-80% and has not decreased. PTSR prevalence was 35.1%, and again there was no change with time. The multivariate Poisson regression model results revealed "old age" and "female" as independent risk factors, but the passage of time did not decrease the risk of PTSR. CONCLUSIONS: Although symptoms in most victims of the Tokyo subway sarin were transient, this large-scale follow-up data analysis revealed that survivors have been suffering from somatic and psychological long-term effects.

Ocular surface histopathological insult following sarin and VX exposure and potential treatments in the rat model.

Eye exposure to organophosphate (OP) chemical warfare irreversible acetylcholinesterase inhibitors, results in long-term miosis and impaired visual function. In contrast to the well-documented miotic and ciliary muscle spasm observed following chemical warfare, OP ocular exposure, little is known regarding the ocular surface histopathological insult. The aim of the present study was to determine the degree of the ocular surface insult following sarin or VX ocular exposure and to evaluate potential anti-cholinergic treatments in counteracting this insult. Rats that were whole body exposed to various sarin concentrations (0.049-43 µg/L; 5 min exposure), showed a dose-dependent miotic response and light reflex impairment. Following whole body sarin exposure, a dose dependent ocular surface histopathological insult was developed. A week following exposure to a low concentration of 0.05 µg/L, conjunctival pathology was observed, while corneal insult was noticed only following exposure to a concentration of 0.5 µg/L and above. Both tissues presented poorer outcomes when exposed to higher sarin concentrations. In contrast, eyes topically exposed to 1 µg sarin demonstrated no ocular insult a week following exposure. On the contrary, topical exposure to 1 µg VX resulted in a significant corneal insult. Anticholinergic treatments such as 0.1% atropine or 2% homatropine, given shortly following VX exposure, counteracted this insult. The results of this study show that not only do anti-cholinergic treatments counteract the miotic response, but also prevent the histopathological insult observed when given shortly following OP exposure.

Opioid Sensitivity in Children with and without Obstructive Sleep Apnea.

BACKGROUND: Opioids are a mainstay of perioperative analgesia. Opioid use in children with obstructive sleep apnea is challenging because of assumptions for increased opioid sensitivity and assumed risk for opioid-induced respiratory depression compared to children without obstructive sleep apnea. These assumptions have not been rigorously tested. This investigation tested the hypothesis that children with obstructive sleep apnea have an increased pharmacodynamic sensitivity to the miotic and respiratory depressant effects of the prototypic µ-opioid agonist remifentanil. METHODS: Children (8 to 14 yr) with or without obstructive sleep apnea were administered a 15-min, fixed-rate remifentanil infusion (0.05, 0.1, or 0.15 µg · kg · min). Each dose group had five patients with and five without obstructive sleep apnea. Plasma remifentanil concentrations were measured by tandem liquid chromatography mass spectrometry. Remifentanil effects were measured via miosis, respiratory rate, and end-expired carbon dioxide. Remifentanil pharmacodynamics (miosis vs. plasma concentration) were compared in children with or without obstructive sleep apnea. RESULTS: Remifentanil administration resulted in miosis in both non-obstructive sleep apnea and obstructive sleep apnea patients. No differences in the relationship between remifentanil concentration and miosis were seen between the two groups at any of the doses administered. The administered dose of remifentanil did not affect respiratory rate or end-expired carbon dioxide in either group. CONCLUSIONS: No differences in the remifentanil concentration-miosis relation were seen in children with or without obstructive sleep apnea. The dose and duration of remifentanil administered did not alter ventilatory parameters in either group.

Post-mortem chemical excitability of the iris should not be used for forensic death time diagnosis.

Post-mortem chemical excitability of the iris is one of the non-temperature-based methods in forensic diagnosis of the time since death. Although several authors reported on their findings, using different measurement methods, currently used time limits are based on a single dissertation which has recently been doubted to be applicable for forensic purpose. We investigated changes in pupil-iris ratio after application of acetylcholine (n = 79) or tropicamide (n = 58) and in controls at upper and lower time limits that are suggested in the current literature, using a digital photography-based measurement method with excellent reliability. We observed "positive," "negative," and "paradox" reactions in both intervention and control conditions at all investigated post-mortem time points, suggesting spontaneous changes in pupil size to be causative for the finding. According to our observations, post-mortem chemical excitability of the iris should not be used in forensic death time estimation, as results may cause false conclusions regarding the correct time point of death and might therefore be strongly misleading.

Pharmacokinetics and -dynamics of intramuscular and intranasal naloxone: an explorative study in healthy volunteers.

PURPOSE: This study aimed to develop a model for pharmacodynamic and pharmacokinetic studies of naloxone antagonism under steady-state opioid agonism and to compare a high-concentration/low-volume intranasal naloxone formulation 8 mg/ml to intramuscular 0.8 mg. METHODS: Two-way crossover in 12 healthy volunteers receiving naloxone while receiving remifentanil by a target-controlled infusion for 102 min. The group were subdivided into three different doses of remifentanil. Blood samples for serum naloxone concentrations, pupillometry and heat pain threshold were measured. RESULTS: The relative bioavailability of intranasal to intramuscular naloxone was 0.75. Pupillometry showed difference in antagonism; the effect was significant in the data set as a whole (p < 0.001) and in all three subgroups (p < 0.02-p < 0.001). Heat pain threshold showed no statistical difference. CONCLUSIONS: A target-controlled infusion of remifentanil provides good conditions for studying the pharmacodynamics of naloxone, and pupillometry was a better modality than heat pain threshold. Intranasal naloxone 0.8 mg is inferior for a similar dose intramuscular. Our design may help to bridge the gap between studies in healthy volunteers and the patient population in need of naloxone for opioid overdose. TRIAL REGISTRATION: clinicaltrials.gov : NCT02307721.

Eficacia y seguridad del uso intraocular de carbacol 0. 01 % para la inducción de miosis intraoperatoria en cirugía de catarata / Efficacy and safety of the intraocular use of 0. 01% carbacol for the induction of intraoperative miosis in cataract surgery

La catarata es definida por la Organización Mundial de la Salud (OMS) como la opacificación del lente cristalino que generalmente ocurre por el envejecimiento, trauma, o alguna enfermedad sistémica, afectando la capacidad visual de la persona. Esta disminución de la capacidad visual o incluso la ceguera, es un problema de salud pública en adultos y adultos mayores. En el Perú, aproximadamente el 0.6 % de la población tiene ceguera, cuya causa en el 47 % de los casos son por las cataratas. El tratamiento indicado para la catarata es la intervención quirúrgica, la cual consiste en reemplazar el cristalino opacificado o catarata por un lente intraocular. Hay dos formas de realizar esto, mediante la extracción extracapsular del cristalino opacificado, o mediante la facoemulsificación del cristalino, que consiste en un proceso de destrucción mediante ondas vibratorias ultrasónicas. Luego de ello, se realiza la implantación de un nuevo lente intraocular con soporte capsular, el cual reemplaza al cristalino permitiendo que el paciente vuelva tener una visión adecuada. Posterior a la implantación del lente intraocular se realiza la inducción de miosis pupilar para mantener el lente dentro de la bolsa capsular, evitar la captura del lente por el iris y el prolapso del iris por las heridas operatorias. La inducción de miosis luego de una intervención por catarata debe realizarse inmediatamente después de la implantación del lente, por lo que la vía de administración indicada es la inyección intraocular del agente miótico. De este modo, se espera que el efecto miótico se prolongue hasta por 24 horas, mientras que la aplicación tópica de un agente miótico se limita a un efecto que bordea las ocho horas, y sólo se puede realizar en el periodo postoperatorio, por lo que se genera un periodo entre la intervención quirúrgica y la aplicación del agente miótico que expone al paciente a las potenciales complicaciones anteriormente mencionadas. Aunque algunos estudios de serie de casos clínicos indican el uso de pilocarpina 2 %, el cual se encuentra disponible en el Petitorio Farmacológico de EsSalud, este medicamento no ha sido aprobado por la FDA para uso intraocular, sólo para uso tópico, dado que su uso intraocular puede ser tóxico o incrementar el riesgo de infecciones intraoculares. Así, en la actualidad EsSalud no cuenta con un medicamento miótico de uso intraocular autorizado, por lo cual, surge la necesidad de evaluar otras alternativas que pudieran ser de beneficio para dichos pacientes. OBJETIVO: objetivo del presente dictamen fue evaluar la eficacia y seguridad del uso intraocular de carbacol 0.01 % para la inducción de miosis intraoperatoria en las intervenciones quirúrgicas por catarata. Carbacol es um colinérgico o parasimpaticomimético potente, que actúa como agonista del receptor de acetilcolina, inhibiendo la acetilcolinesterasa y estimulando tanto los receptores muscarínicos como nicotínicos, produciendo miosis a través de la constricción del iris y del cuerpo ciliar, y reduciendo la presión intraocular. TECNOLOGÍA SANITARIA DE INTERÉS: CARBACOL. Carbacol, también conocido como carbamilcolina, es un colinérgico o parasimpaticomimético potente, que actúa como agonista del receptor de acetilcolina, inhibiendo la acetilcolinesterasa y estimulando tanto los receptores muscarínicos como nicotínicos, produciendo constricción del iris y del cuerpo ciliar y además reduciendo la presión intraocular. El agente colinérgico fue aprobado por la Administración de Drogas y Alimentos (FDA, por sus siglas en inglés) en el año 2002 (FDA, 2015). METODOLOGÍA: Se realizó una búsqueda sin restricción de idioma hasta mayo del 2018. La formulación de la estrategia de búsqueda incluyó los criterios de elegibilidad, los términos controlados propios de cada base y términos libres. Asimismo, se buscaron otros documentos potencialmente elegibles a través de la revisión del listado de referencias de los documentos seleccionados para lectura a texto completo. Por último, la selección de la evidencia siguió el flujograma mostrado en la subsección de resultados. RESULTADOS: Luego de la búsqueda sistemática realizada, se identificaron dos ensayos clínicos aleatorizados (ECA) Beasley, 1972 y Solomon et al., 1998; y el estudio de serie de casos de Pekel et al., 2014. Si bien estos estudios muestran algunas limitaciones que serán analizadas más adelante, es la evidencia de mayor relevancia en torno al uso de carbacol para la inducción de miosis intraoperatoria en las intervenciones quirúrgicas por catarata. Con respecto a la eficacia de carbacol en la inducción de miosis, el estudio de Beasley, 1972 muestra que el efecto miótico a los dos minutos de la inyección intraocular es significativamente mayor en carbacol, con respecto a placebo (p<0.01) y que el efecto miótico persiste por lo menos por 15 horas. Por otro lado, a la séptima semana postoperatoria, se observó una incidencia significativamente menor de sinequias anteriores periféricas (SAP) en el grupo que recibió carbacol (11 %), en comparación al grupo que recibió a placebo (35 %). Al analizar el impacto sobre la calidad de vida por parte de carbacol mediante el cuestionario modificado de SF-36, el cual mide la percepción del paciente sobre su estado de salud, el estudio de Solomon et al., 1998 muestra que carbacol incrementa la agudeza visual durante el primer día postoperatorio, con respecto a placebo, y muestra una diferencia estadísticamente significativa en el porcentaje de sujetos que pueden descender las escaleras sin ayuda durante la primera semana posterior a la intervención quirúrgica, tanto en un ambiente con luz brillante (p=0.007) o con luz tenue (p=0.037), siendo un potencial factor protector en pacientes con riesgo de presentar caídas acci Con respecto a los eventos adversos, los estudios evaluados no encontraron casos de inflamación intraocular ni de cefalea frontal. El estudio Pekel et al., 2015 muestra que sólo en el primer día postoperatorio hubo un menor volumen macular total (VMD y del grosor macular central (GMC) con respecto al volumen preoperatorio. Mientras que, durante el seguimiento (al primer día, a la primera semana y al primer mes) no se encontraron diferencias estadísticamente significativas en la presencia de edema macular, ni en el calibre de los vasos retinianos (CVR) al comparar los pacientes que recibieron carbacol con los que no lo recibieron. dentales y fractura de caderas. CONCLUSIONES: El presente dictamen preliminar muestra la evidencia disponible hasta mayo 2018 con respecto al uso intraocular de carbacol 0.01 % en comparación con placebo para la inducción de miosis intraoperatoria en pacientes operados de cataratas. No se encontraron guías de práctica clínica, revisiones sistemáticas ni evaluaciones de tecnologías sanitarias que respondan la pregunta PICO de la presente evaluación. Finalmente, se identificaron dos ECA y un estudio de serie de casos como sustento para la elaboración del presente dictamen preliminar. Al evaluar la eficacia de carbacol en la inducción de miosis, el estudio Beasley, 1972 muestra que carbacol genera miosis dentro de los dos minutos de ser aplicado y que su efecto perdura por más de 15 horas. Esto se traduce en una menor incidencia de SAP a la sétima semana postoperatorio, con respecto a placebo. Aunque no se aprecia diferencia en la conservación de la integridad de la cámara vítrea. Con respecto a los eventos adversos, los estudios evaluados no observaron casos de inflamación intraocular ni de cefalea frontal, mientras que el estudio Pekel et al., 2015 muestra que carbacol disminuye el volumen macular total (VMT) y el grosor macular central (GMT) en el primer día postoperatorio, mas no en la primera semana, ni primer mes. Por otro lado, no se ve afectado el calibre de los vasos retinianos (CVR). Estos resultados muestran una cierta protección ante el edema macular en el postoperatorio inmediato y ausencia de secuelas en la morfología macular, sin embargo, se debe tener en cuenta el posible sesgo de medición que conlleva. En resumen, carbacol es un agente miótico que inicia su acción dentro de los dos minutos de su inyección, manteniendo su efecto por más de 15 horas, generando un beneficio en el periodo postoperatorio inmediato en la agudeza visual y en el volumen macular total. Asimismo, los estudios no reportan eventos adversos como edema macular, cefalea, y, por el contrario, refieren una reducción en la incidencia de SAP, mas no hay una diferencia en la preservación de la integridad de la cámara vítrea, al ser comparado con placebo. Con respecto a la calidad de vida en el postoperatorio, se observa un inicio más temprano de la deambulación y autonomía en el uso de las escaleras, lo que podría tener un impacto positivo en el estilo de vida de los pacientes intervenidos. Por lo expuesto, el Instituto de Evaluaciones de Tecnologías en Salud e Investigación - IETSI aprueba el uso de carbacol, según lo establecido en el Anexo N.° 1. La vigencia del presente dictamen preliminar es de dos años a partir de la fecha de publicación.

Acetylcholine chloride 1% usage for intraoperative cataract surgery miosis / Cloridrato de Acetilcolina 1% na obtenção da miose intraoperatória na cirurgia de catarata

Abstract Objective: To test the efficacy of Acetylcholine chloride use in obtaining intraoperative miosis on phacoemulsification cataract surgery. Methods: Patients with cataract diagnosis and elected for surgical phacoemulsification procedure were selected. All patients underwent conventional phacoemulsification procedure performed by a single surgeon and all patients had 0.2 ml of Acetylcholine chloride 1% irrigated in the anterior chamber at the end of the surgery. The pupillary diameter was measured immediately before the beginning of surgery, immediately before and two minutes after the use of acetylcholine chloride 1%. Results: A total of 30 eyes from 30 patients were included in the study. 18 were female, and mean age was of 69.5 years with a 7.2y standard deviation on the population study. The mean pupillary diameter immediately before the beginning of surgery was 7.5 mm with a standard deviation of 0.56 mm; the mean pupillary diameter immediately before the acetylcholine chloride 1% use (after the intraocular lens im-plantation) was 7.1 mm with a standard deviation of 0.57 mm. The mean pupillary diameter two minutes after the use of acetylcholine chloride 1% in the anterior chamber was 3.4 mm with standard deviation of 0.66 mm. The mean maximum action time of ACH chloride 1% was 64 seconds, with a standard deviation of 8 seconds. The mean intraocular pressure on the first postoperative day was 19.1 mmHg with a standard deviation of 2.45 mmHg. Conclusion: We conclude that acetylcholine chloride 1% is an important drug to obtaining intraoperative miosis in cataract surgery.

Resumo Objetivo: Demonstrar a eficácia do cloridrato de acetilcolina 1% na obtenção da miose intraoperatória na cirurgia de catarata pela técnica de facoemulsificação. Métodos: Pacientes com diagnóstico de catarata e indicação de cirurgia foram selecionados para participar do presente estudo. Todos os pacientes foram operados pela técnica de facoemulsificação convencional pelo mesmo cirurgião, todos foram submetidos à aplicação de 0,2 ml do cloridrato de acetilcolina 1% na câmara anterior ao final do procedimento cirúrgico. A medida do diâmetro pupilar foi realizada imediatamente antes do início da cirurgia, imediatamente antes do uso do cloridrato de acetilcolina 1% e após 2 minutos. Resultados: Foram estudados 30 olhos de 30 pacientes, destes, 18 eram do sexo feminino, a média de idade do estudo foi de 69,5 anos com desvio padrão de 7,2 anos. A média do diâmetro pupilar imediatamente antes do início da cirurgia foi 7,55 mm com desvio padrão de 0,56mm, a média do diâmetro pupilar imediatamente antes do uso do cloridrato de acetilcolina 1% (após implante da lente intraocular no saco capsular) foi 7,1mm com desvio padrão de 0,57mm. A média do diâmetro pupilar após 2 minutos da aplicação da acetilcolina na câmara anterior foi de 3,4 mm com desvio padrão de 0,66mm. O tempo médio de ação máxima do medicamento foi de 64 segundos, com desvio padrão de 8 segundos. A média da pressão intraocular no primeiro dia do pós-operatório foi de 19,1 mmHg com desvio padrão de 2,45mmHg. Conclusão: O estudo acima mostrou que a acetilcolina apresenta boa eficácia na obtenção de miose intraoperatória na cirurgia de facoemulsificação, permitindo uma maior facilidade na confecções das suturas corneanas ou corneo-escleral, reduzindo a incidência de sinéquias anteriores periféricas. Concluimos que o cloridrato de acetilcolina 1% é um importante medicamento na obtenção da miose intraoperatória na cirurgia de catarata.

Factors associated with the deaths of men poisoned by carbamato ("chumbinho"). / Fatores associados aos óbitos entre homens envenenados por carbamato ("chumbinho").

Objective To determine the factors associated with death in poisoning victims by carbamate ("Chumbinho"). Method Retrospective study, epidemiological case-control based on poisoning reporting forms, a poison control center located in the metropolitan region of Rio de Janeiro. We used 24 notification forms of poisoning in men aged 20 to 59 years with poisoning by carbamate history from 2005 to 2009. The records were randomly selected, respecting the ratio 1:3 (a case to three controls). The age range was 23-58 years, average 43.83 years. Results The most frequent symptoms were myosis (OR=1.0; 95% CI: 0.27 to 3.69 p=1.0.), drooling (OR=0.83; 95% CI. 0.22 to 3.12 p=0.78), and dyspnea (OR=0.66; 95% CI: 0:14-3.03 p=0.59). Conclusion The deaths were associated with drooling, miosis and dyspnea and a strong association with pulmonary rales, bronchospasm and pulmonary snoring.

Fatores associados aos óbitos entre homens envenenados por carbamato ("chumbinho") / Factores de muertes de hombres envenenados por carbamato ("chumbinho") / Factors associated with the deaths of men poisoned by carbamato ("chumbinho")

RESUMO Objetivo Determinar os fatores associados aos óbitos em vítimas de envenenamento por carbamato (“chumbinho”). Método Estudo retrospectivo, epidemiológico tipo caso-controle, baseado nas fichas de notificação de intoxicação do centro de controle de intoxicações localizado na região metropolitana do Rio de Janeiro. Foram utilizadas 24 fichas de notificação de intoxicações de homens dos 20 aos 59 anos com história de envenenamento por carbamato entre 2005 e 2009. As fichas foram sorteadas aleatoriamente, respeitando-se a razão de 1:3 (um caso para três controles). A faixa etária variou de 23 a 58 anos; a média 43,83 anos. Resultados Os sintomas mais recorrentes foram: miose (OR = 1.0; IC 95%: 0,27 – 3,69. p= 1.0), sialorreia (OR = 0,83; IC 95%: 0,22 – 3,12. p= 0,78), dispneia (OR = 0,66; IC 95%: 0.14 – 3,03. p= 0,59). Conclusão Os óbitos apresentaram associação com sialorreia, miose e dispneia e uma forte associação com estertores pulmonares, broncoespasmos e os roncos pulmonares.

RESUMEN Objetivo Determinar los factores asociados a la muerte en las víctimas de envenenamiento por carbamato (“Chumbinho”). Método Estudio retrospectivo, epidemiológico de caso y control sobre el envenenamiento en los formularios de notificación un centro de control de envenenamiento localizado en la región metropolitana de Río de Janeiro. Utilizamos 24 formularios de notificación de envenenamiento en hombres de 20 a 59 años con intoxicación por el carbamato de 2005 a 2009. Los registros fueron seleccionados al azar, respetando la proporción de 1:3 (un caso y tres controles). El rango de edad fue de 23 a 58 años, promedio de 43,83 años. Resultados Los síntomas más frecuentes fueron miosis (OR = 1,0; IC del 95%: 0,27 a 3,69 p = 1.0.), Babeo (OR = 0,83, IC 95% 0,22-3,12 p. = 0,78), disnea (OR = 0,66; IC del 95%: 0:14 - 3.03 p = 0.59). Conclusión Las muertes se asociaron con babeo, miosis y disnea, y una fuerte asociación con estertores pulmonares, broncoespasmo y el ronquido pulmonar.

ABSTRACT Objective To determine the factors associated with death in poisoning victims by carbamate (“Chumbinho”). Method Retrospective study, epidemiological case-control based on poisoning reporting forms, a poison control center located in the metropolitan region of Rio de Janeiro. We used 24 notification forms of poisoning in men aged 20 to 59 years with poisoning by carbamate history from 2005 to 2009. The records were randomly selected, respecting the ratio 1:3 (a case to three controls). The age range was 23-58 years, average 43.83 years. Results The most frequent symptoms were myosis (OR=1.0; 95% CI: 0.27 to 3.69 p=1.0.), drooling (OR=0.83; 95% CI. 0.22 to 3.12 p=0.78), and dyspnea (OR=0.66; 95% CI: 0:14-3.03 p=0.59). Conclusion The deaths were associated with drooling, miosis and dyspnea and a strong association with pulmonary rales, bronchospasm and pulmonary snoring.

Amitraz: a mimicker of organophosphate poisoning.

Amitraz is used as an ectoparasiticide for dogs and cattle. Human poisoning due to amitraz may be misdiagnosed as organophosphate/carbamate (OPC) toxicity, since amitraz poisoning shares several clinical features (miosis, bradycardia and hypotension) encountered with OPC poisoning. A 19-year-old man with an alleged history of suicidal ingestion of a pesticide presented with drowsiness and was found to have constricted pupils, hypotension and bradycardia. He was diagnosed as a case of OPC poisoning and was treated with atropine and pralidoxime prior to presentation to our centre. Absence of a hypersecretory state, and the presence of hyperglycaemia and hypothermia along with a normal serum cholinesterase level suggested an alternate possibility. Retrieval of the poison container confirmed the diagnosis of amitraz poisoning. The patient made a rapid recovery with supportive management. Clinician awareness is key to successful management of this poisoning, which carries a good prognosis.

Prophylaxis with human serum butyrylcholinesterase protects Göttingen minipigs exposed to a lethal high-dose of sarin vapor.

Serum-derived human butyrylcholinesterase (Hu BChE) is a stoichiometric bioscavenger that is being developed as a potential prophylactic nerve agent countermeasure. Previously, we reported the prophylactic efficacy of Hu BChE in Göttingen minipigs against a whole-body exposure to 4.1mg/m(3) of sarin (GB) vapor, which produced lethality over 60min. Since the toxicity of nerve agent is concentration-dependent, in the present study, we investigated the toxic effects of an almost 3-fold higher rate of GB vapor exposure and the ability of Hu BChE to protect minipigs against this exposure. Male minipigs were subjected to: (1) air exposure; (2) GB vapor exposure; or (3) pretreatment with 7.5mg/kg of Hu BChE by i.m. injection, 24h prior to whole-body exposure to 11.4mg/m(3) of GB vapor for 10min. Electrocardiogram, electroencephalogram, and pupil size were monitored throughout exposure. Blood drawn before and throughout exposure was analyzed for blood gases, electrolytes, metabolites, acetylcholinesterase and BChE activities, and amount of GB bound to red blood cells and plasma. A novel finding was that saline-treated animals exposed to GB vapor did not develop any seizures, but manifested a variety of cardiac and whole blood toxic signs and rapidly died due to respiratory failure. Strikingly, pre-treatment with 7.5mg/kg of Hu BChE not only prevented lethality, but also avoided all cardiac toxic signs manifested in the non-treated cohort. Thus, Hu BChE alone can serve as an effective prophylactic countermeasure versus a lethal high-dose exposure to GB vapor.

Use of Remifentanil in a Novel Clinical Paradigm to Characterize Onset and Duration of Opioid Blockade by Samidorphan, a Potent µ-Receptor Antagonist.

A novel clinical study design was used to evaluate the blockade of a selective short-acting µ-opioid agonist (remifentanil) in 24 opioid-experienced subjects. Samidorphan (3-carboxamido-4-hydroxynaltrexone) is a novel opioid modulator with µ-antagonist properties. Objective (pupil diameter) and subjective (visual analog scale) responses to repeated remifentanil and saline infusion challenges were assessed after single oral administration of placebo (day 1) and samidorphan (day 2). Complete blockade persisted with samidorphan for 24 hours for pupil miosis and 48 hours for the drug liking visual analog scale. Samidorphan effects persisted beyond measurable samidorphan exposure (t½ = 7 hours). Samidorphan was associated with complete blockade of remifentanil, and the duration supports daily administration. This study used a novel approach with multiple administrations of remifentanil to successfully demonstrate a durable effect with samidorphan and a rapid and potent blockade of physiological and subjective µ-opioid effects.