Aminomethylphosphonic Acid (AMPA), a Glyphosate Metabolite, Decreases Plasma Cholinesterase Activity in Rats.

Glyphosate, a widely used herbicide, is linked to a plethora of deleterious effects in both clinical and preclinical studies. Nevertheless, the effects of its main metabolite, aminomethylphosphonic acid (AMPA), whose half-life in soil is even longer than that of glyphosate, have been little explored. On this basis, as a first approach, in this work, we report that intraperitoneal (i.p.) administration of AMPA or glyphosate (at 10, 56, and 100 mg/kg) decreased, to a similar extent, plasma cholinesterase (ChE) activity in acutely exposed rats. Moreover, we designed an experimental protocol to analyze and compare the effects of AMPA and glyphosate on human plasma ChE activity; this protocol consisted of adding these compounds to human plasma to subsequently test the effects of this plasma on the contraction to acetylcholine (ACh) in the frog rectus abdominis muscle (an indirect estimate of ChE activity). Accordingly, this muscular contraction to ACh was evaluated before and after pre-incubation of ACh with (i) plasma alone, (ii) plasma with AMPA, and (iii) plasma with glyphosate. Our results indicate that AMPA, like glyphosate, decreased ChE activity in the plasma of rats (when given i.p.) and humans (when added in vitro), suggesting that both xenobiotics may exert similar toxicological effects.

Cholinergic Crisis Owing to Distigmine Bromide Complicated by Hyperosmolar Hyperglycemic State.

Distigmine bromide is widely used to treat neurogenic bladder and causes cholinergic crisis, a serious side effect. We herein report about a patient with distigmine bromide-induced cholinergic crisis complicated by a hyperosmolar hyperglycemic state (HHS). On admission, the patient was diagnosed with HHS based on the medical history and laboratory test results. However, she also had bradycardia, miosis, and low plasma cholinesterase activity. We later found that she had received distigmine bromide, which led to a diagnosis of cholinergic crisis. We suggest that the exacerbation of pathology, including HHS, can cause cholinergic crisis in patients receiving distigmine bromide.

Correlation and prognostic significance of serum amylase, serum lipase, and plasma cholinesterase in acute organophosphorus poisoning.

BACKGROUND: Organophosphorus (OP) are substances that are originally produced by the reaction of alcohols and phosphoric acid. These OP compounds are the main components of herbicides, pesticides, and insecticides. These are easily available in developing country like India; there is lack of awareness about these chemicals which results in high morbidity and mortality. AIMS AND OBJECTIVES: To estimate levels of amylase, lipase, plasma cholinesterase in acute OP poisoning. To assess severity of OP poisoning by using plasma cholinesterase levels and correlating it with other two markers. Predicting the severity of acute OP poisoning by using these biochemical markers. MATERIALS AND METHODS: A hospital-based observational study was conducted on 100 subjects who were clinically diagnosed of acute OP poisoning. Subjects of either gender of all age-groups were included in the study. On admission, plasma cholinesterase, serum amylase, and serum lipase were measured. Based on plasma cholinesterase activity at the time of admission, subjects were divided into three groups. Group I-having 20-50% of plasma cholinesterase activity; Group II-10-20% of plasma cholinesterase activity; and Group III <10% of plasma cholinesterase activity. RESULTS: Among 100 patients it was seen that serum amylase and serum lipase were negatively correlated with plasma cholinesterase levels and it was statistically significant. It was seen that serum amylase had the highest diagnostic accuracy for assessing severity of poisoning, 10 deaths were there in which 6 had <10% of plasma cholinesterase activity, 8 out of these 10 patients had elevated amylase level. CONCLUSION: OP poisoning is associated with elevated amylase level. Serum amylase, lipase can be used as an additional prognostic indicator along with plasma cholinesterase levels. Serum amylase could be considered as a better predictor of severity than lipase.

Plasma cholinesterase activity as an environmental impact biomarker in juvenile green turtles (Chelonia mydas) / Atividade da colinesterase plasmática como biomarcador de impacto ambiental em tartarugas verdes juvenis (Chelonia mydas)

The objective of this study was to evaluate the enzymatic activity of plasma cholinesterase in Chelonia mydas marine turtles belonging to two populations, according to their capture sites, under the absence and probable influence of anthropic effects. A total of 74 animals were used and later divided into two groups, based on the capture site. Blood samples were collected from all captured animals, which were then released into the sea at the site of capture. A descriptive statistical analysis of the plasma cholinesterase activity values and an analysis comparing these values based on the capture site were performed. Samples of heparinized plasma from animals captured at the two different sites were analyzed. Plasma cholinesterase activity ranged from 121 to 248U/L, with a mean and standard deviation of 186.1±30.68U/L. When comparing plasma cholinesterase activity values in individuals based on the capture site, a significant difference was observed. Establishing reference values for different sea turtle populations is necessary to interpret future sampling results and to allow sea turtles to be used as sentinels of ecosystem health. Future studies are needed to evaluate other populations and the activity of plasma cholinesterase in juvenile marine turtles, in relation to environmental contamination.(AU)

O objetivo desse estudo foi avaliar a atividade enzimática da colinesterase plasmática em tartarugas marinhas da espécie Chelonia mydas em duas populações de acordo com o local de captura, sob ausência e provável influência de efeito antrópico. Foi utilizado um total de 74 animais e posteriormente divididos em dois grupos de acordo com o local de captura. Foram coletadas amostras de sangue de todos os animais capturados e em seguida liberados ao mar no mesmo local. Foi realizada uma análise estatística descritiva dos valores da atividade plasmática de colinesterase do total de animais e análise comparando os valores de acordo com o local de captura. Foram analisadas amostras de plasma heparinizado de animais capturados em dois locais distintos. Os valores da atividade plasmática de colinesterase variaram de 121 a 248U/L, com média e desvio padrão de 186.1±30.7U/L. Quando comparados os valores de atividade plasmática da colinesterase nos indivíduos de acordo com o local de captura, foi observada diferença significativa. O estabelecimento de valores de referência para diferentes populações de tartarugas marinhas são necessários para interpretar os futuros resultados amostrais e permitir que as tartarugas marinhas sejam usadas como sentinelas da saúde do ecossistema. Estudos futuros são necessários para avaliar outras populações e a atividade da colinesterase plasmática de tartarugas marinhas juvenis em relação à contaminação ambiental.(AU)

Evaluation of the inhibitory effect of abamectin on mammalian butyrylcholinesterase: Enzyme kinetic and molecular docking studies.

Abamectin, a blend of the natural avermectins B1a and B1b, is a widely-used insecticide/miticide with relatively low toxicity to mammals. Exposure to high doses of it, however, leads to cholinergic-like neurotoxic effects. Butyrylcholinesterase, which is best known for its abundant presence in plasma, is a serine hydrolase loosely coupled with the cholinergic system. It protects and supports the neurotransmitter function of its sister enzyme acetylcholinesterase. Here, using experimental and computational studies, we provide evidence demonstrating that abamectin is a potent (IC50 = 10.6 µM; Ki = 2.26 ± 0.35 µM) inhibitor of horse serum butyrylcholinesterase and that it interacts with the enzyme in a reversible, competitive manner predictively to block the mouth of the active-site gorge of the enzyme and to bind to several critical residues that normally bind/hydrolyze choline esters.

Duración del bloqueo neuromuscular con succinilcolina y su relación con niveles de colinesterasa plasmática en pacientes sépticos: Hospital Central Universitario Dr. Antonio María Pineda / Neuromuscular blockade duration with succinylcholine and its correlation with levels of plasma cholinesterase in septic patients: Hospital Central Universitario Dr. Antonio María Pineda

La succinilcolina es un fármaco neuromuscular despolarizante generalmente utilizado en el contexto de protocolo de intubación de secuencia rápida indicada en pacientes en los cuales es necesario asegurar la vía aérea en menos de sesenta segundos. Se realizó un estudio descriptivo transversal con el objetivo de determinar la duración del bloqueo neuromuscular con succinilcolina y los niveles de colinesterasa plasmática en pacientes sépticos intervenidos en el Hospital Central Universitario Dr. Antonio María Pineda. Se incluyeron 30 pacientes con sepsis con un promedio de edad de 49,6 ± 17,4 años y predominio del sexo masculino (70%); la principal indicación de cirugía abdominal fue obstrucción intestinal (36,6%) y peritonitis secundaria (23,3%). Los valores de colinesterasa plasmática se registraron disminuidos en 42,8% de los hombres y 33,3% de las mujeres encontrándose valores promedios de 5554,1 ± 1220,5 U/L y 4770,1 ± 1627,4 U/L, respectivamente. La duración del bloqueo neuromuscular fue mayor de 14 minutos en 66,6% de las mujeres; el promedio de duración fue de 14,4 ± 5,1 min (mujeres) y 9,4 ± 4,3 min en hombres. Hubo una pobre correlación entre los niveles de colinesterasa plasmática y la duración así como el tiempo de recuperación del bloqueo neuromuscular. En conclusión, el bloqueo neuromuscular prolongado debido a la baja actividad de la colinesterasa después de la administración de succinilcolina se presenta en menos de la mitad de los pacientes sépticos estudiados(AU)

Succinylcholine is a depolarizing neuromuscular drug generally used in the context of rapid sequence intubation indicated in patients in whom it is necessary to secure the airway in less than sixty seconds. A descriptive cross-sectional study was conducted in order to determine the duration of neuromuscular blockade with succinylcholine and plasma cholinesterase levels in septic patients admitted at Hospital Central Universitario Dr. Antonio Maria Pineda. A sample of 30 patients with sepsis were studied, with a mean age of 49.6 ± 17.4 years, predominantly male (70%). The main indication for abdominal surgery was intestinal obstruction (36.6%) and secondary peritonitis (23.3%). Diminished values of plasma cholinesterase were recorded in 42.8% of men and 33.3% of women; mean plasma levels were 5554.1 ± 1220.5 U/L and 4770.1 ± 1627.4 U/L, respectively. Duration of neuromuscular blockade was longer in women (66.6%) with an average duration of 14.4 ± 5.1 min and 9.4 ± 4.3 min for men. A poor correlation between cholinesterase plasmatic levels and duration as well as time of recovery of neuromuscular blockage was found. Prolonged neuromuscular blockade is due to low cholinesterase activity after administration of succinylcholine and occurs in less than half of septic patients studied(AU)

Leukocyte count: A reliable marker for the severity of organophosphate intoxication?

INTRODUCTION: Organophosphorus poisoning (OPP) is a major public health problem in developing countries like India. Leukocyte count is a simple and inexpensive test, and elevated count is associated with acute inflammation and increased oxidative stress-like OPP. This study was done to correlate the severity of acute OPP with leukocyte count and also to assess the prognosis. MATERIALS AND METHODS: A prospective, observational clinical study was done on 80 patients suspected of OPP of age >15 years admitted to emergency unit at a tertiary rural teaching health-care center of Central India. Serum cholinesterase level and leukocyte count were estimated at the time of admission in all patients and severity of OPP was assessed according to Peradeniya organophosphorus poisoning (POP) scale. RESULTS: The mean age of the patients was 33.52 years (standard deviation [SD] 11.62) in males and 27.30 years (SD 7.33) in females. Among them, 57 (71.25%) were males and 23 (28.75%) were females. The severity of poisoning was directly correlated with serum cholinesterase level (P = 0.0001). Leukocyte count had a sensitivity of 60%, specificity of 76%, and negative predictive value of 85% if counts were more than 12,000 and 30% sensitivity, 95% specificity, and 80% negative predictive value if counts were more than 15,000 in predicting mortality in patients with OPP. CONCLUSION: Leukocyte count levels on admission can be used a prognostic marker in patients with OP poisoning.

Valores de colinesterasa plasmática y eritrocitaria con ácido 6-6'-ditiodinicotínico (DTNA) como indicador / Plasma and eritrocitary cholinesterase values with 6-6'-dithiodinicotinic acid (DTNA) as indicator / Valores da colinesterase plasmática e eritrocitária utilizando o ácido 6-6-ditiodinicotínico (DTNA) como indicador

Resumen Se realizó un estudio descriptivo transversal empleando ácido 6-6'-ditiodinicotinico (DTNA) como indicador para calcular los valores de la actividad de colinesterasa plasmática (AchP) y eritrocitaria (AchE) humana y estandarizarlos para ser utilizados como indicadores de riesgo laboral por exposición a organofosforados y carbamates en la población de la zona cafetera de Colombia. Se eligió esta técnica pues es una alternativa precisa, sencilla y económica: con pocos interferentes permite analizar AchP y AchE, no se tiene que corregir con hemoglobina; el DTNA es estable congelado o refrigerado y permite analizar muchas muestras en poco tiempo. Se evaluaron 819 muestras de agricultores. La AchE fue significativamente mayor en las personas menores de 45 años y en personas no fumigadoras, la AchP fue mayor en los fumigadores; esto es un indicador de que la población fumigadora se encuentra expuesta a organofosforados y carbamatos de forma prolongada. Se sugiere utilizar como valores máximos de referencia de la AchE y AchP 11378 U/L y 10354 U/L, respectivamente como indicadores de intervención ocupacional.

Abstract A cross-sectional descriptive study using 6-6'-dithiodinicotinic acid (DTNA) as an indicator was performed to calculate the values of plasma cholinesterase (AchP) and erythrocyte (AchE) activity and to standardize them to be used as indicators of occupational risk by exposure to organophosphates and carbamates in the population of the Colombian Coffee Growing Area. This method was chosen because it is an accurate, simple, and nonexpensive alternative: with few interferents it allows measuring both AchP and AchE, it does not have to be corrected with hemoglobin; The DTNA is stable frozen or refrigerated and allows to analyze many samples in a short time. A number of 819 samples from farmers were evaluated. While AchE was significantly higher in people under 45 years and in non-fumigating people, AchP was higher in fumigators; this result is an indicator that the fumigant population is exposed to organophosphates and carbamates on a long-term basis. It is suggested to use as maximum reference values of AchE and AchP 11378 U / L and 10354 U / L, respectively as indicators of occupational intervention.

Resumo Foi realizado um estudo descritivo transversal usando ácido 6-6'-ditiodinicotinico (DTNA) como indicador a fim de calcular os valores de atividade da colinesterase plasmática (AchP) e eritrocitária (AchE) humana e padronizar estes valores para ser utilizados na região cafeteira da Colômbia. Esta técnica foi elegida porque e uma alternativa precisa, simples e econômica: tem poucos interferentes e permite analisar AchP e AchE, não deve corrigir-se com hemoglobina; o DNTA e estável congelado ou refrigerado e permite analisar muitas amostras em pouco tempo. Foram avaliadas 819 amostras de agricultores. A AchE foi significativamente maior nas pessoas com menos de 45 anos e em pessoas não pulverizadoras, a AchP foi maior nas pessoas pulverizadoras; isso e um indicador de que a população pulverizadora encontra-se exposta a organofosforados e carbamatos de maneira prolongada. Sugere-se utilizar como valores máximos de referência da AchE e AchP 11378 U/L y 10354 U/L, respectivamente como indicadores de intervenção ocupacional.

The use of self-reported symptoms as a proxy for acute organophosphate poisoning after exposure to chlorpyrifos 50% plus cypermethrin 5% among Nepali farmers: a randomized, double-blind, placebo-controlled, crossover study.

BACKGROUND: Previous studies stating a high prevalence of occupational acute pesticide poisoning in developing countries have mainly relied on measurements of the rather non-specific self-reported acute pesticide poisoning symptoms. Only a few studies have measured the biomarker plasma cholinesterase (PchE) activity, in addition to the symptoms, when assessing occupational acute pesticide poisoning. This study evaluated self-reported symptoms as a proxy for acute organophosphate poisoning among Nepali farmers by examining self-reported acute organophosphate poisoning symptoms and PchE activity in response to occupational acute organophosphate exposure. METHODS: We performed a randomized, double-blind, placebo-controlled, crossover trial among 42 Nepali commercial vegetable farmers. The farmers were randomly assigned (ratio 1:1) to a 2-h organophosphate (chlorpyrifos 50% plus cypermethrin 5%: moderately hazardous) spray session or a 2-h placebo spray session, and after 7 days' washout, the farmers were assigned to the other spray session. Before and after each spray session farmers were interviewed about acute organophosphate poisoning symptoms and PchE activity was measured. Analyses were conducted with a Two Sample T-test and Mann Whitney U-test. RESULTS: We found no difference in the symptom sum or PchE activity from baseline to follow up among farmers spraying with organophosphate (symptom sum difference -1, p = 0.737; PchE mean difference 0.02 U/mL, p = 0.220), placebo (symptom sum difference 9, p = 0.394; PchE mean difference 0.02 U/mL, p = 0.133), or when comparing organophosphate to placebo (symptom p = 0.378; PchE p = 0.775). However, a high percentage of the farmers reported having one or more symptoms both at baseline and at follow up in the organophosphate spray session (baseline 47.6%, follow up 45.2%) and placebo spray session (baseline 35.7%, follow up 50.0%), and 14.3% of the farmers reported three or more symptoms after the organophosphate spray session as well as after the placebo spray session. CONCLUSION: We found a general presence of acute organophosphate symptoms among the farmers regardless of organophosphate exposure or poisoning. Thus, self-reported acute organophosphate symptoms seem to be a poor proxy for acute organophosphate poisoning as the occurrence of these symptoms is not necessarily associated with acute organophosphate poisoning. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02838303 . Registered 19 July 2016. Retrospectively registered.

Is prevention of acute pesticide poisoning effective and efficient, with Locally Adapted Personal Protective Equipment? A randomized crossover study among farmers in Chitwan, Nepal.

BACKGROUND: Farmers' risk of pesticide poisoning can be reduced with personal protective equipment but in low-income countries farmers' use of such equipment is limited. OBJECTIVE: To examine the effectiveness and efficiency of Locally Adapted Personal Protective Equipment to reduce organophosphate exposure among farmers. METHODS: In a crossover study, 45 male farmers from Chitwan, Nepal, were randomly allocated to work as usual applying organophosphate pesticides wearing Locally Adapted Personal Protective Equipment or Daily Practice Clothing. For seven days before each experiment, each farmer abstained from using pesticides. Before and after organophosphate application, an interview surveys and blood tests were carried out, and analyzed with paired t-test, frequencies and percentages. RESULTS: The difference between follow-up mean for acute organophosphate poisoning symptoms in the two groups was 0.13 [95% CI -0.22;0.49] and for plasma cholinesterase (U/ml) -0.03 [95% CI -0.11;0.06]. The difference between follow-up mean minus baseline mean for acute organophosphate poisoning symptoms in the two groups was 0.29 [95% CI -0.26;0.84] and for plasma cholinesterase (U/ml) -0.01 [95% CI --0.08;0.06]. Wearing the Locally Adapted Personal Protective Equipment versus Daily Practice Clothing gave the following results, respectively: comfort 75.6% versus 100%, sense of heat 64.4% versus 31.3%, other problems 44.4% versus 33.3%, likeability 95.6% versus 77.8%. CONCLUSION: We cannot support the expectation that our farmers in Chitwan, Nepal working with Locally Adapted Personal Protective Equipment would have fewer acute organophosphate poisoning symptoms, higher plasma cholinesterase (U/mL) and find it more efficient to work with the equipment than farmers working with their Daily Practice Clothing. Based on the farmers' working behavior, compounds used, intensity and exposure duration we conclude that Locally Adapted Personal Protective Equipment does not provide additional protection during usual work practices. However, our Locally Adapted Personal Protective Equipment might offer protection from (certain) accidental overexposure. Trial Registration NCT02137317.

Serum and Plasma Cholinesterase Activity in the Cape Griffon Vulture (Gyps coprotheres).

Vulture (Accipitridae) poisonings are a concern in South Africa, with hundreds of birds dying annually. Although some of these poisonings are accidental, there has been an increase in the number of intentional baiting of poached rhinoceros (Rhinocerotidae) and elephant (Elephantidae) carcasses to kill vultures that alert officials to poaching sites by circling overhead. The primary chemicals implicated are the organophosphorous and carbamate compounds. Although most poisoning events can be identified by dead vultures surrounding the scavenged carcass, weak birds are occasionally found and brought to rehabilitation centers for treatment. The treating veterinarian needs to make an informed decision on the cause of illness or poisoning prior to treatment. We established the reference interval for serum and plasma cholinesterase activity in the Cape Griffon Vulture ( Gyps coprotheres ) as 591.58-1,528.26 U/L, providing a clinical assay for determining potential exposure to cholinesterase-depressing pesticides. Both manual and automated samplers were used with the butyrylthiocholine method. Species reference intervals for both serum and plasma cholinesterase showed good correlation and manual and automated measurements yielded similar results.

Plasma cholinesterase activity of rats, western grey kangaroos, alpacas, sheep, cattle, and horses.

INTRODUCTION: Plasma cholinesterase activity levels of various species may be of interest to toxicologists or pathologists working with chemicals that interfere with the activity of plasma cholinesterase. METHODS: We used a pH titration method to measure the plasma cholinesterase activity of six mammalian species. RESULTS: Plasma cholinesterase activity varied up to 50-fold between species: sheep (88 ± 45 nM acetylcholine degraded per ml of test plasma per minute), cattle (94 ± 35), western grey kangaroos (126 ± 92), alpaca (364 ± 70), rats (390 ± 118) and horses (4539 ± 721). DISCUSSION: We present a simple, effective technique for the assay of plasma cholinesterase activity levels from a range of species. Although labour-intensive, it requires only basic laboratory equipment.

Prognostic significance of various biochemical parameters in acute organophosphorus poisoning.

BACKGROUND: Organophosphorus (OP) compounds are a heterogeneous group of insecticides widely used in agricultural industry. These OP compounds are likely to have more adverse effects in developing countries like India due to its easy availability and less awareness which results in high morbidity and mortality. AIMS AND OBJECTIVES: 1. To estimate plasma cholinesterase, amylase, lipase and, creatine phosphokinase (CPK) in acute OP poisoning. 2. To correlate these biochemical parameters with plasma cholinesterase levels in OP poisoning. 3. To determine the use of a biochemical marker in predicting the severity of acute OP poisoning. MATERIALS AND METHODS: A hospital based observational study was conducted on 53 subjects who have clinically diagnosed of acute OP poisoning and admitted in emergency unit of a tertiary care rural hospital. Subjects of either gender of all age-groups were included in the study. On admission, plasma cholinesterase, serum amylase, lipase and CPK were measured. Based on plasma cholinesterase activity at the time of admission, subjects were divided into three groups. Group I-having 20-50% of plasma cholinesterase activity; Group II-10-20% of plasma cholinesterase activity; and group III-<10% of plasma cholinesterase activity. RESULTS: Serum amylase, lipase and CPK were negatively correlated with plasma cholinesterase levels. Serum amylase showed statistically significant negative correlation with plasma cholinesterase. Serum amylase showed the highest diagnostic accuracy for assessing severity of poisoning followed by CPK and Lipase. CONCLUSION: OP poisoning is associated with hyperamylasemia. Serum amylase, lipase and CPK can be used as an additional prognostic indicator with plasma cholinesterase levels. Serum amylase could be considered as a better predictor of severity followed by CPK and lipase.

[Plasma cholinesterase activity in hepatic diseases]. / Étude de l'activité de la cholinestérase plasmatique au cours des atteintes hépatiques.

Plasma cholinesterase activity (ChE) may vary in some pathological circumstances. We studied the changes in activity of this enzyme according to the type of liver injury, to assess the interest of this parameter in the diagnosis of liver diseases. Our study was performed on 102 patients with different liver diseases and 53 healthy controls. The ChE activity was lower in patients compared to control group (p < 0.0001), and more pronounced in cirrhotic patients compared to those suffering from hepatitis. Elevated activities of AST, ALT, GGT and ALP and bilirubinemia, and decreased albuminemia were noted in patients compared to controls (p < 0.001). Hypoalbuminemia was significantly important in cirrhotic patients compared to those suffering from cholestasis or hepatitis. A correlation between ChE and bilirubin, albumin and serum protein was found in patients with cirrhosis or those with chronic hepatitis. A significantly lower activity of ChE was found in patients with hepatic insufficiency (HI). In case of suspicion of HI, the prescription of ChE activity could guide or confirm the diagnosis of the impairment.

Clinical Significance of Immediate Determination of Plasma Cholinesterase Level in Patients Presenting with Organophosphate Ingestion at the Time of Hospitalization

PURPOSE: Plasma cholinesterase is a sensitive measure determining the severity of organophosphate intoxication. The author evaluated the usefulness of the plasma cholinesterase level as a prognostic indicator of the severity of organophosphate intoxication. METHODS: From June 1999 to May 2001, 55 patients presented with organophosphate insecticide intoxication to the Emergency Medical Center of the Chonnam National University Hospital, and these were enrolled in this study. The plasma cholinesterase activities of these 55 patients were determined at the time of presentation. The relationships between the plasma cholinesterase level and the clinical variables of organophosphate toxicity, quantity of ingested poison, elapsed time to gastric lavage, and the APACHE score at the time of hospitalization were analyzed. RESULTS: The plasma cholinesterase activity significantly decreased in association with the degree of toxicity of the poison (p<0.001), elapsed time to gastric lavage (p<0.001), and the quantity of organophosphate ingested (p=0.013). In the 55 patients, lower plasma values of cholinesterase were observed in patients with longer durations of mechanical ventilation (r=-0.717, p<0.001) and in patients who developed pneumonia during treatment (r=-0.538, p<0.001). Also, decreased cholinesterase activity correlated with a higher APACHE score (r=-0.672, p<0.001). CONCLUSION: These results suggest that immediate determination of the plasma cholinesterase level at the time of hospitalization may be useful as a prognostic indicator in patients with organophosphate intoxication.

The infusion rate of mivacurium or atracurium for cesarean section compared with gynecological procedures

Mivacurium is mainly metabolized by plasma cholinesterase, whereas atracurium is removed by Hofman elimination. The purpose of this study was to compare the infusion rate of atracurium and mivacurium in maintaining surgical relaxation, and to compare their recovery indices between parturients and non-pregnant women. Muscle relaxation was maintained by the continuous infusion of relaxants to retain the first response of train-of-four (TOF) at 5% of control. When mivacurium was used, Bolus-T5 (duration from the end of mivacurium bolus injection to 5% single twitch recovery) was measured. After discontinuing the infusion, the recovery index was measured. The infusion rate of mivacurium, not atracurium, was significantly lower in parturients and Bolus-T5 of parturients was significantly longer than that of non-pregnant women. There was no significant difference in the recovery indices of both relaxants. The authors concluded that the infusion rate of mivacurium in maintaining muscle relaxation in parturients should be reduced compared to the rate in non-pregnant women and measuring Bolus-T5 may be helpful in determining the infusion rate to maintain muscle relaxation.

Influence of Various Muscle Relaxants on the Plasma Cholinesterase Activity / 대한마취과학회지

BACKGROUND: The reduction in the plasma cholinesterase (PChE) level results in slow to hydrolysis of succinylcholine (SCC) and mivacurium (MIV). The factors altering the level of the normal enzyme in human could be considered under the several conditions. We investigated in the present study whether the drugs induced decreases in normal PChE activity after administration of various muscle relaxants during anesthesia are evident and how these results should be influenced to the time course of neuromuscular blockade produced by SCC and MIV. METHODS: Young adult patients of ASA class I or II scheduled for elective surgery requiring muscle relaxation were premedicated and anesthesia was maintained with nitrous oxide in oxygen with increment of thiopentone or fentanyl as required. In the neuromuscular monitoring, surface electrodes were applied on the ulnar nerve at wrist. Supramaximal transcutaneous single twitch stimulation (1 Hz) during onset and 0.1 Hz during recovery of neuromuscular blockade induced by various muscle relaxants delivered by a peripheral nerve stimulator was applied. Twitch response of thumb adductor was measured mechanomyographically using 2 kg Load Cell Strain Gauge with thumb piece modification. Recordings were made on a Gould recorder. PChE levels were measured by the modified Garry method after induction of anesthesia and, at 3, 10, 20 and 30 min following administration of 2 x ED95 of pancuronium (PAN), vecuronium (VEC) and atracurium (ATR). Neuromuscular recordings were measured with onset time defined as lag time and manifest time, and recovery time defined as clinical duration, recovery index and total duration. RESULTS: The levels of PChE were significantly reduced after administration of PAN and VEC (p<0.05). Onset times were significantly shorten but recovery time in the group given MIV pretreated by small dose of PAN was significantly prolonged (p<0.05). And there were a evidence to prolong recovery time in the group pretreated by small dose of VEC but not significant. CONCLUSIONS: It is concluded that aminosteroidal derivative neuromuscular blocking agents have presumably evidence induced decreases in PChE activity rather than benzylisoquinolinium derivative neuromuscular blocking agents.

Prolonged Apnea after Cesarean Section in Patient with Low Level of Plasma Cholinesterase Activity: A case report / 대한마취과학회지

Succinylcholine-induced prolonged neuromuscular blockade may occur in patients with either a low level of plasma cholinesterase activity or genotypically abnormal form of that enzyme. We experienced a case of succinylcholine-induced prolonged apnea due to a low level of plasma cholinesterase activity. A 31-year-old woman, full term primigravida, underwent cesarean section for breech presentation under general anesthesia. Familial and past medical history were nonspecific and preoperative physical and laboratory findings were within normal range. After operation, delayed apnea was detected and lasted for about one hour. We performed controlled and assisted ventilation for two and half hours. Plasma cholinesterase activity measured 30.00 IU/L (colorimetric method, normal value: 1130~1960 IU/L) at the first postoperative day. She was discharged on 7th postoperative day without any sequelae. From follow-up study after six months, it measured 1.02 U/ml (EIA, normal value: 7~9 U/ml).

Effect of Pancuronium, Vecuronium and Atracurium to the Plasma Cholinesterase Activity / 대한마취과학회지

BACKGROUND: Succinylcholine is metabolized by plasma cholinesterase (PChE). When it was pretreated by small doses of nondepolarizing muscle relaxants in order to minimize the side effects, there are evidences to be associated with alteration in the duration of action. This study is investigated whether the responses would be related to the enzymatic activities. METHODS: In 21 adult patients, ASA class I or II, PChE levels were measured by the modified Garry method after induction of anesthesia (control value) and at 3, 10, 20 and 30 min following administration of pancuronium 0.1 mg/kg, vecuronium 0.1 mg/kg and atracurium 0.5 mg/kg. Data were expressed as mean (SEM). RESULTS: The levels of PChE were significantly lower (p<0.05) than the control values at 3, 10, 20 and 30 min after given pancuronium as 4764 (270), 4777 (261), 4796 (306) and 4740 (332) IU/L respectively and after given vecuronium as 5004 (341), 5051 (329), 4969 (340) and 4960 (340) IU/L respectively whereas enzyme levels after given atracurium were not significant differences to compare the control values as 5153 (336), 5136 (320) 5124 (312) and 5151 (275) respectively. CONCLUSIONS: The results of present study show that both pancuronium and vecuronium may possibly inhibit PChE activity but this was not affected by atracurium.

Effects of Multiple Exposures to Pesticides on Plasma Cholinesterase Activity and p-nitrophenol Excretion in Rats / 예방의학회지

The effects of multiple exposures to pesticides on plasma cholinesterase(ChE) activities and urinary p-nitrophenol excretion were evaluated in rats. Rats were received single dose i.p. with LD50/100(mg/kg) of organophosphorous(OP), organophosphorous-organochroline(OP-OC), organophosphorous-carbamate(OP-CAB), organophosphorous-organoarsenate(OP-OA) pesticides for 4 consecutive days. In repeated administration of pesticides, plasma ChE activities were decreased, but urinary p-nitrophenol were increased after the first injection and then decreased gradually. The recovery rates of ChE activities and p-nitrophenol excretion at 48 hours after the fourth infection were delayed in comparison with the baseline value of 24 hours before the first injection. Statistical significances were found between OP and other groups except OP-OA group after the second injection in plasma ChE activities, but in urinary p-nitrophenol excretion there was statistical significance only between OP and OP-CAB.