Repeated sugammadex reversal of muscle relaxation during lumbar spine surgery with intraoperative neurophysiological multimodal monitoring / Reversión repetida del bloqueo neuromuscular con sugammadex en cirugía del raquis lumbar, con monitorización neurofisiológica multimodal intraoperatoria

Intraoperative neurophysiological monitoring during spine surgery is usually acomplished avoiding muscle relaxants. A case of intraoperative sugammadex partial reversal of the neuromuscular blockade allowing adequate monitoring during spine surgery is presented. A 38 year-old man was scheduled for discectomy and vertebral arthrodesis throughout anterior and posterior approaches. Anesthesia consisted of total intravenous anesthesia plus rocuronium. Intraoperatively monitoring was needed, and the muscle relaxant reverted twice with low dose sugammadex in order to obtain adequate responses. The doses of sugammadex used were conservatively selected (0.1mg/kg boluses increases, total dose needed 0.4mg/kg). Both motor evoqued potentials, and electromyographic responses were deemed adequate by the neurophysiologist. If muscle relaxation was needed in the context described, this approach could be useful to prevent neurological sequelae. This is the first study using very low dose sugammadex to reverse rocuronium intraoperatively and to re-establish the neuromuscular blockade (AU)

La monitorización neurofisiológica intraoperatoria en cirugía de raquis se suele llevar a cabo evitando los bloqueantes neuromusculares. Presentamos el caso de un paciente en el que se empleó reversión parcial del bloqueo neuromuscular que permitió la monitorización intraoperatoria con respuestas adecuadas. Un paciente varón de 38 años fue sometido a discectomía y artrodesis mediante abordajes consecutivos anterior y posterior. Se procedió con anestesia intravenosa y rocuronio como bloqueante neuromuscular. Se precisó monitorización intraoperatoria y el bloqueante neuromuscular fue revertido por 2 veces con dosis bajas de sugammadex para obtener las respuestas adecuadas. Las dosis de sugammadex usadas fueron seleccionadas de forma conservadora (bolos incrementales de 0,1mg/kg, dosis total requerida 0,4mg/kg). Tanto los potenciales evocados motores como las respuestas electromiográficas fueron juzgadas adecuadas por el neurofisiólogo. Si se precisa relajación muscular en el contexto descrito, esta aproximación podría ser útil para contribuir a la prevención de secuelas neurológicas. Este es el primer estudio en el que se emplean dosis muy bajas de sugammadex intraoperatoriamente para revertir rocuronio y restablecer, consecutivamente, el bloqueo neuromuscular (AU)

Determination of sugammadex in human plasma, urine, and dialysate using a high-performance liquid chromatography/tandem mass spectrometry assay.

Sugammadex (Bridion®, Merck Sharp & Dohme Corp., Oss, The Netherlands) is a modified γ-cyclodextrin which has the ability to reverse the neuromuscular blockade induced by the steroidal neuromuscular blocking agents rocuronium and vecuronium. The objective of the current study is to describe the bioanalytical methods that have been developed and validated according to US Food and Drug Administration guidelines on bioanalytical method validation, and subsequently applied to determine total sugammadex (i.e., free sugammadex plus sugammadex bound to the neuromuscular blocking agent) in human heparinized plasma, urine and dialysate. Sugammadex was extracted from human plasma and urine using solid phase extraction with Isolute HAX 96-well extraction plates; no extraction was performed on dialysate samples. Samples from plasma, urine, and dialysate were analyzed on a Polaris® C18-A PEEK (polyaryletheretherketone) analytical column (50 mm × 4.6 mm internal diameter, 5 µm) with a linear mobile phase gradient of 0.1% (v/v) formic acid in water:methanol from 70:30 to 20:80. The flow rate was 1 mL/min with a total run time for each injection of 6 min. Tandem mass spectrometric detection was conducted using multiple reaction monitoring under negative ion mode with a turbo ion-spray interface to quantify the concentration of sugammadex. Inter- and intra-assay precision and accuracy were within pre-defined acceptance limits. The presence of rocuronium did not interfere with the assay in plasma, urine or dialysate; similarly, vecuronium did not interfere with the plasma assay (not tested for interference in urine or dialysate). Sugammadex was found to be stable in plasma, urine and dialysate in the short-term at room temperature, in the long-term at -20°C, and after several freeze/thaw cycles. The validated bioanalytical methods developed here have been successfully applied in a series of clinical studies for the determination of total sugammadex in plasma, urine and dialysate.

Bloqueo neuromuscular inducido por neostigmina en el músculo Corrugator supercilii / Neostigmine-induced neuromuscular blockade in the corrugator supercilii muscle

Objetivo: Investigar si una dosis de neostigmina administrada cuando el adductor pollicis presenta dos respuestas al tren de cuatro estímulos (TOF), puede producir una atenuación del cociente del TOF en el músculo corrugator supercilii (CS). Pacientes y métodos: Se diseñó un estudio casos-control con pacientes ASA I-II entre 18 y 65 años. Se utilizaron dos acelerómetros: nervio cubital/músculo aductor del pulgar y nervio facial/músculo CS. El bloqueo neuromuscular se indujo con rocuronio 0,6 mg Kg–1. Cuando el TOF ratio en el aductor del pulgar mostraba tres respuestas se administró neostigmina (40 μg Kg–1). Si en ese momento el TOF ratio en el CS disminuía 10 o más puntos se clasificaba como “caso”. Se midieron las variables edad, sexo, peso, talla, índice de masa corporal (IMC), duración y TOF ratio en el CS cuando se administró neostigmina. Resultados: Se incluyeron 10 casos y 10 controles. No hubo diferencias significativas excepto en el TOF ratio en el CS (media, [DE]): 70,9% (17,8%) en los casos frente a 35,3% (7,8%) en los controles (p < 0,001). Conclusiones: En nuestros pacientes administrar neostigmina tras la aparición de la tercera respuesta al TOF en el aductor del pulgar se asoció con un descenso del TOF ratio en el CS. La similitud del bloqueo del corrugator con el diafragma y la laringe tiene interés sobre la relevancia clínica del fenómeno(AU)

Objective: To investigate whether a single dose of neostigmine, administered when the adductor pollicis muscle presents 2 twitches in train-of-four (TOF) stimulation, can reduce the TOF ratio in the corrugator supercilii muscle. Patients and methods: We designed a case-control study of patients between 18 and 65 years of age classified ASA 1-2. We used 2 accelerometers—1 for the cubital nerve/thumb adductor muscle and 1 for the facial nerve/corrugator supercilii muscle. Neuromuscular blockade was induced with 0.6 mg·kg–1 of rocuronium, and 40 μg·kg–1 of neostigmine was administered at the third twitch in the TOF in the thumb adductor. If the TOF ratio in the corrugator supercilii fell by 10% or more at that time, the patient was classified as a case. We recorded the age, sex, weight, height, body mass index, duration of the procedure, and TOF ratio in the corrugator supercilii muscle when the neostigmine was administered. Results: Ten cases and 10 controls were enrolled. No significant differences between cases and controls were found in any variables except the mean (SD) TOF ratio in the corrugator supercilii muscle: 70.9% (17.8%) in cases and 35.3% (7.8%) in controls (P<.001). Conclusions: In our patients, administration of neostigmine after the appearance of the third twitch in TOF stimulation of the thumb adductor was associated with a reduction in the TOF ratio in the corrugator supercilii. The similarity between blockades of the corrugator muscle, the diaphragm, and the larynx is of clinical interest(AU)

Application of high-performance liquid chromatography with amperometric and coulometric detection to the analysis of SZ1677, a new neuromuscular blocking agent, and its two derivatives.

A HPLC method with amperometric and coulometric detection for the determination of SZ1677 and its two derivatives SZ1676 and SZ1823 has been developed. This active substance is under development (clinical trial) and there are no analytical methods published for the determination of SZ1677 thus far. The limit of quantitation for SZ1677 was 25 and 100 ng ml(-1) by the coulometric and amperometric detection, respectively. The elaborate method for the simultaneous analysis of SZ1677 and its two derivatives proved to be fast, precise, accurate and sensitive.

Comparación entre el bromuro de pancuronio genérico y el Pavulon®1 / Comparison between generic pancuronium bromide and Pavulon®1

Históricamente se ha planteado el conflicto sobre la eficacia y la seguridad terapéutica entre marcas genéricas y la marca original, lo cual llevó a desarrollar el siguiente estudio. Objetivos: 1) realizar ensayos fisicoquímicos de ampollas que contenían 4 mg/2ml de bromuro de pancuronio, en una marca genérica (G) y en una original (P = Pavulon®), 2) determinar la eficacia y la seguridad terapéutica de ambas drogas, y 3) comparar los resultados entre ambas marcas, tomando como patrón de referencia la marca original. Materiales y métodos: Ensayos fisicoquímicos realizados conforme la Farmacopea Británica 2001 (FB). Eficacia y seguridad terapéutica evaluada mediante un estudio prospectivo, randomizado y doble ciego en cincuenta pacientes ASA I-II a quienes se administró 2 mcg/kg de citrato de fentanilo, 5 mg/kg de tiopental sódico cinco minutos después y 0.1 mg/kg de bromuro de pancuronio. La anestesia se mantuvo con sevoflurano 2 por ciento. Se evaluó el tiempo T1 para alcanzar los valores porcentuales 95,75,25,0 y 25 de recuperación o duración clínica. Comparación: Test de Mann - Whitney, p < 0.05. Resultados: Los ensayos fisicoquímicos para el grupo genérico y el Pavulon® cumplieron con las especificaciones de la FB. En el grupo genérico, los tiempos necesarios para que T1 disminuya hasta 95 y 75 por ciento resultaron respectivamente 33.15 y 48.36 segundos; para que disminuya al 25 por ciento y 0 por ciento, 1.50 Y 2.97 minutos, y la duración clínica fue de 108.99 minutos. En el grupo Pavulon®, el tiempo requerido para T1 = 95 Y 75 por ciento fue de 24.89 y 41.54 segundos respectivamente, mientras que para llegar al 25 y 0 por ciento fueron necesarios 1.34 y 2.71 minutos; la duración clínica en este grupo fue de 111.99 minutos. Conclusiones: Los tiempos evaluados no arrojaron diferencia estadística significativa entre ambas marcas.

Comparación entre el bromuro de pancuronio genérico y el Pavulon½1 / Comparison between generic pancuronium bromide and Pavulon½1

Históricamente se ha planteado el conflicto sobre la eficacia y la seguridad terapéutica entre marcas genéricas y la marca original, lo cual llevó a desarrollar el siguiente estudio. Objetivos: 1) realizar ensayos fisicoquímicos de ampollas que contenían 4 mg/2ml de bromuro de pancuronio, en una marca genérica (G) y en una original (P = Pavulon½), 2) determinar la eficacia y la seguridad terapéutica de ambas drogas, y 3) comparar los resultados entre ambas marcas, tomando como patrón de referencia la marca original. Materiales y métodos: Ensayos fisicoquímicos realizados conforme la Farmacopea Británica 2001 (FB). Eficacia y seguridad terapéutica evaluada mediante un estudio prospectivo, randomizado y doble ciego en cincuenta pacientes ASA I-II a quienes se administró 2 mcg/kg de citrato de fentanilo, 5 mg/kg de tiopental sódico cinco minutos después y 0.1 mg/kg de bromuro de pancuronio. La anestesia se mantuvo con sevoflurano 2 por ciento. Se evaluó el tiempo T1 para alcanzar los valores porcentuales 95,75,25,0 y 25 de recuperación o duración clínica. Comparación: Test de Mann - Whitney, p < 0.05. Resultados: Los ensayos fisicoquímicos para el grupo genérico y el Pavulon½ cumplieron con las especificaciones de la FB. En el grupo genérico, los tiempos necesarios para que T1 disminuya hasta 95 y 75 por ciento resultaron respectivamente 33.15 y 48.36 segundos; para que disminuya al 25 por ciento y 0 por ciento, 1.50 Y 2.97 minutos, y la duración clínica fue de 108.99 minutos. En el grupo Pavulon½, el tiempo requerido para T1 = 95 Y 75 por ciento fue de 24.89 y 41.54 segundos respectivamente, mientras que para llegar al 25 y 0 por ciento fueron necesarios 1.34 y 2.71 minutos; la duración clínica en este grupo fue de 111.99 minutos. Conclusiones: Los tiempos evaluados no arrojaron diferencia estadística significativa entre ambas marcas. (AU)

Nuevos bloqueadores neuromusculares

En los últimos años se han comercializado dos nuevos bloqueadores neuromusculares (BNM), cisatracurio y rocuronio, especialmente diseñados para su uso en pacientes críticos. El cisatracurio tiene menos toxicidad que el atracurio. Al necesitarse menos dosis para alcanzar el mismo efecto, se libera menos histamina y se produce menos laudanósido que con el atracurio. El rocuronio presenta diferencias con respecto a su predecesor, el vecuronio, ya que tiene mayor rapidez de acción y no se metaboliza a metabolitos activos. Ambos BNM aportan, a nuestro juicio, potenciales ventajas y mayor seguridad para su uso en los pacientes críticos. Sin embargo, su uso prolongado no está exento de posibles complicaciones, como la producción de alteraciones neuromusculares. Una correcta monitorización de sus efectos para proporcionar la menor dosis necesaria durante el menor tiempo posible puede evitar estas complicaciones. (AU)

Occurrence of paralytic toxin in Taiwanese crab Atergatopsis germaini.

Paralytic toxicity was detected by paralytic shellfish poison bioassay for all 17 specimens of the xanthid crab A. germaini collected from northern Taiwan in November 1993. The average toxicity of crab specimens was 3809 +/- 2591 mouse units (mean +/- S.D.). The toxin was partially purified from ethanolic extract of the crab by ultrafiltration and Bio-Gel P-2 column chromatography. Electrophoresis, TLC, HPLC, ultraviolet spectrum and GC-MS analyses indicated that the crab toxin was composed of gonyautoxin 3 (50%), neosaxitoxin and saxitoxin (7%), a novel paralytic shellfish poison-like toxin (40%) and tetrodotoxin (3%).

Identification of urinary and biliary conjugated metabolites of the neuromuscular blocker 51W89 by liquid chromatography/mass spectrometry.

Cisatracurium, (1R, 1'R, 2R, 2'R)-2,2-[1,5-pentanediylbis-[oxy(3-oxo- 3,1-propanediyl]]bis[1-[(3,4-dimethoxyphenyl)-methyl]-1,2,3,4- tetrahydro-6,7-dimethoxy-2-methylisoquinolinium] dibenzenesulphonate (51W89), is an intermediate-acting neuromuscular blocking agent. 51W89 is one of ten isomers contained in Tracrium (atracurium besylate) and represents approximately 15 percent of the atracurium mixture. Clinical studies have indicated that 51W89 is more potent and is significantly weaker as a histamine releaser than atracurium. In vitro studies in human plasma have shown that, like atracurium, 51W89 spontaneously degrades at physiological pH by Hoffmann elimination to form laudanosine and the quaternary monoacrylate. Subsequent ester hydrolysis of the monoacrylate generates the monoquaternary alcohol. In rat plasma, 51W89 is also metabolized by non-specific carboxylesterases to the monoquaternary alcohol and the monoquaternary acid, the former being rapidly hydrolysed further to the more stable acid. It has been reported that laudanosine can be further metabolized via N-dimethylation to yield tetrahydropapaverine. The rate-limiting step in the degradation of 51W89 in human plasma is Hofmann elimination, whilst in rat plasma, the action of non-specific carboxylesterases is rate limiting. As part of the development of 51W89, the disposition of 14C-51W89 following a single intravenous bolus dose was studied in various animal species and humans. In the present work, we describe the identification of 51W89 metabolites in urine and bile from these studies by high performance liquid chromatography/mass spectrometry using pneumatically-assisted electrospray ionization coupled to an on-line radioactivity monitor.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of cooking on the concentration of toxins associated with paralytic shellfish poison in lobster hepatopancreas.

The hepatopancreases from lobsters (Homarus americanus) obtained from two locations in eastern Canada (Gaspé and Bay of Fundy) were analysed for paralytic shellfish poisons (PSP) before and after the shellfish were cooked by boiling or steaming. Forty-five lobsters from each location were divided into three groups of 15. Two of the groups were boiled or steamed while the third was uncooked for comparison purposes. The hepatopancreases of all lobsters were individually analysed for total PSP toxicity using the standard mouse bioassay procedure. Individual toxins were determined in each sample using a high-performance liquid chromatographic procedure employing pre-chromatographic oxidation of the toxins to form fluorescent derivatives. The results demonstrated that boiling or steaming reduced total toxicity (measured as saxitoxin equivalents per hepatopancreas) by approximately 65% compared to values obtained from raw lobsters. Of the individual toxins studied, saxitoxin decreased by about 60% with both the cooking treatments while gonyautoxins 2 and 3 (combined) decreased by almost 100% in the Gaspé samples and by about 90% in the Fundy samples with the same cooking treatments. Trace amounts of saxitoxin or gonyautoxins 2 and 3 were detected in some samples of tail or claw meat before or after cooking. In vitro boiling of raw hepatopancreas for up to 30 min led to no change in total or individual PSP concentration, indicating that the toxins in cooked lobster are not removed through chemical decomposition but are leached out during the loss of water.

[Analysis of steroids. Part 44: Analytical investigation of the intermediates of the synthesis of pipecuronium bromide (Arduan)]. / Adatok a szteránvázas vegyületek analitikájához 44. Pipecuronium bromid (Arduan) szintézis intermedierjeinek analitikája.

The following methods are described for the analytical investigation of the intermediates of the synthesis of pipecuronium bromide (Arduan) (for the numbering of the intermediates and their impurities see Figure 1.). 1. Gas chromatographic methods (capillary GC using fused silica capillaries Ultra-2 and Silar 10C WCOT) for the impurity profiling of intermediates I, II, IV and V including the identification and spectroscopic characterization of their impurities; 2. TLC methods for the similar characterisation of the further intermediates (III, VI, VII and VIII); 3. Gas chromatographic assay methods for IV and V using fused silica capillary technique and internal standards; 4. Potentiometric titration methods for the determination of VII and VIII using 0.1 M hydrochloric acid as the titrant.

[Analysis of steroids. Part 45: Analytical investigation of pipecuronium bromide (Arduan)]. / Adatok a szteránvázas vegyületek analitikájához 45. Pipecuronium bromid (Arduan) analitikai vizsgálata.

The following methods are described for the analytical investigation of pipecuronium bromide. 1. HPLC method. Of the several systems tried for the separation and quantification of impurities and degradation products the best results were obtained using silica as the stationary phase and 43:43:14 mixture of methanol, acetonitrile and concentrated aqueous ammonia containing 0.1 mole/l each of ammonium chloride and ammonium carbonate as the eluent. The validation of this method is presented. The above described aggressive eluent can be successfully replaced by an ion-pairing system using silica as the stationary phase and 96:4 mixture of acetonitrile and water containing 0.1 mole/l sodium perchlorate as the eluent. 2. Thin-layer chromatography. TLC systems are described for the separation and densitometric quantification of the impurities and degradation products of pipecuronium bromide. 3. Spectrophotometry. Two methods are described. The ester groups of the molecule can be determined by the iron(III)-hydroxamate method while for the ion-pair extraction of the quaternary ammonium steroid picric acid or bromthymol blue are used as the reagents. 4. Titrimetry. In addition to the titration with acetous perchloric acid for the assay of the bulk material a microtitration method is described for the determination of pipecuronium bromide in individual lyophylized ampoules (potentiometric titration with 0.1 M silver nitrate).

Persistence of allergy to anaesthetic drugs.

Intradermal testing and RIA testing for specific IgE antibodies to neuromuscular blocking drugs (NMBDs) were performed in patients referred to an Anaesthetic Allergy Clinic. Six patients were initially investigated four to 29 years after clinical anaphylaxis during anaesthesia and two of these patients and sixteen others were investigated by intradermal testing on two occasions at least four years apart. Seven patients had RIA tests for NMBD-specific IgE antibodies on two occasions at the time of skin testing. In all but two patients the evidence for drug-specific antibodies persisted 4-29 years after the reactions. In one patient all tests became negative and in another the skin test became negative but the positive RIA persisted. Evidence of antibodies to NMBDs persisted in 21 of 22 patients who had had anaphylactic reactions to these drugs during anaesthesia. In the absence of evidence of allergy diminishing with time in the majority of patients it would seem wise to avoid drugs responsible for reactions for the rest of the patient's life.

Bioassay of organophosphate nerve agents in soil using neuronal tissue cultures.

A soil sample originating from an area of suspected chemical warfare activity was subjected to chemical analysis and bioassay. Sarin and several related compounds were confirmed in the soil by capillary column gas chromatography-mass spectrometry (GC-MS); however, the binding of these compounds to the soil hindered quantitation. The chemical results were then compared to those obtained by bioassay in primary cultures of chick embryo forebrain neurons. By comparing the sample's anticholinesterase activity against those of purified standards in chick embryo neuron cultures, a reasonable agreement was found between the chemical and bioassay semi-quantitative estimates of sarin content in the soil extract. Furthermore, the in vitro system appears to offer a sensitive technique for the estimation of sarin remaining bound to the soil following solvent extraction as well as for an assessment of the potential toxicity of the contaminated soil in vivo.

[Construction and application of all-solid-state aconitine electrochemical detector in flow injection analysis].

A new kind of all-solid-state electrochemical detector for very toxic alkaloids such as aconitine, mesaconitine and hypaconitine has been studied. It exhibits Nernstian response for these alkaloids with a slope of 56 mV/decade over the concentration range of 3 x 10(-5)-1 x 10(-2) mol/L at pH 2-7 under the flow condition. Direct potentiometry for the determination of aconitine in Aconitum kusnezoffii Reichb., Aconitum carmichaeli Debx. and Xiaohuoluo Wan showed average recoveries of 98.5, 98.3 and 96.8% and relative standard deviations of 1.8, 2.4 and 3.5%, respectively. It can be used for the determination of very toxic alkaloids in the above mentioned samples by flow injection analysis. It also can be used for the study of the hydrolytic kinetics of aconitine.

Estimation of impurity profiles of drugs and related materials. Part VIII: Combined application of high-performance liquid chromatography and NMR spectroscopy in the impurity profiling of drugs.

The usefulness of the joint application of HPLC and NMR spectroscopy in drug impurity profiling is demonstrated by the following examples: (1) identification of Z and E isomers of 17 alpha-ethynyl-4-oestrene-3 beta, 17-diol-3-acetate-17-(3'-acetoxy-2'-butenoate) in ethynodiol diacetate; (2) identification of the p-tolyl analogue as the impurity of enalapril maleate; (3) identification and quantification of 2'-dehydro-pipecuronium bromide in pipecuronium bromide. The possibilities of utilizing NMR spectroscopy for the identification and quantification of the impurities with and without their isolation are discussed.

[Determination of the main alkaloids in wu tou (aconite) by TLC-densitometry].

A method of TLC densitometry was established in order to determine the main alkaloids: mesaconitine, aconitine and hypaconitine in Aconite root. The powdered sample was alkalinized by ammonia and macerated with ether for 24 h. The mixture was then centrifuged, the residue was washed three times each with 2 ml of fresh ether, the combined ether extract was evaporated to dryness and then dissolved in 1 ml of dichloromethane. Standard solution and sample solution were spotted on a sillca gel GF254 plate, and developed with cyclohexane-ethyl acetate-diethylamine (8:1:1), the chromatogram was observed under UV light as dark spots. A Shimazu TLC model 910 was used for scanning at lambda s 236 nm and lambda R 350 nm by reflection mode. Linear calibration curves were obtained for the 3 constituents in the range of 2-6 micrograms. The average recoveries of masaconitine, aconitine and hypaconitine were 97.3, 96.4, 99.1% and the variation coefficients were 1.81, 1.72, 1.18%, respectively. The spots were stable for more than 24 h. Samples from various sources were analyzed.