Phlebotomy resulting in controlled hypovolaemia to prevent blood loss in major hepatic resections (PRICE-1): a pilot randomized clinical trial for feasibility.

BACKGROUND: Major liver resection is associated with blood loss and transfusion. Observational data suggest that hypovolaemic phlebotomy can reduce these risks. This feasibility RCT compared hypovolaemic phlebotomy with the standard of care, to inform a future multicentre trial. METHODS: Patients undergoing major liver resections were enrolled between June 2016 and January 2018. Randomization was done during surgery and the surgeons were blinded to the group allocation. For hypovolaemic phlebotomy, 7-10 ml per kg whole blood was removed, without intravenous fluid replacement. Co-primary outcomes were feasibility and estimated blood loss (EBL). RESULTS: A total of 62 patients were randomized to hypovolaemic phlebotomy (31) or standard care (31), at a rate of 3·1 patients per month, thus meeting the co-primary feasibility endpoint. The median EBL difference was -111 ml (P = 0·456). Among patients at high risk of transfusion, the median EBL difference was -448 ml (P = 0·069). Secondary feasibility endpoints were met: enrolment, blinding and target phlebotomy (mean(s.d.) 7·6(1·9) ml per kg). Blinded surgeons perceived that parenchymal resection was easier with hypovolaemic phlebotomy than standard care (16 of 31 versus 10 of 31 respectively), and guessed that hypovolaemic phlebotomy was being used with an accuracy of 65 per cent (20 of 31). There was no significant difference in overall complications (10 of 31 versus 15 of 31 patients), major complications or transfusion. Among those at high risk, transfusion was required in two of 15 versus three of nine patients (P = 0·326). CONCLUSION: Endpoints were met successfully, but no difference in EBL was found in this feasibility study. A multicentre trial (PRICE-2) powered to identify a difference in perioperative blood transfusion is justified. Registration number: NCT02548910 ( http://www.clinicaltrials.gov).

ANTECEDENTES: La resección hepática mayor se asocia con pérdida de sangre y necesidad de transfusión. Datos observacionales sugieren que la flebotomía hipovolémica (hypovolaemic phlebotomy, HP) puede reducir estos riesgos. Este ensayo clínico aleatorizado (randomised clinical trial, RCT) de factibilidad comparó HP con el tratamiento estándar con el fin de proporcionar información para un futuro ensayo multicéntrico. MÉTODOS: Se reclutaron pacientes sometidos a resecciones hepáticas mayores entre junio 2016 y enero 2018. La aleatorización se realizó durante el intraoperatorio y los cirujanos eran ciegos al resultado de la asignación. Para la HP, se extrajeron 7-10 mL/kg de sangre total, sin reposición de líquidos intravenosos. Los resultados primarios fueron la factibilidad y la pérdida de sangre estimada (estimated blood loss, EBL). RESULTADOS: Un total de 62 pacientes se aleatorizaron a HP (n = 31) y a tratamiento estándar (n = 31), a un ritmo de 3,1 pacientes/mes, cumpliendo el co-objetivo primario de la factibilidad. La mediana de la diferencia de EBL fue 11 mL (P = 0,46). Entre los pacientes con alto riesgo de transfusión, la mediana de la diferencia de EBL fue 448 mL (P = 0,069). Los objetivos secundarios de factibilidad se consiguieron: reclutamiento (89%), cegamiento (98%), y objetivo de la flebotomía (7,6 ± 1,9 mL/kg). Los cirujanos que fueron cegados percibieron que la resección fue más fácil con la HP (52% versus 32%) y acertaron el uso de HP con una exactitud del 65%. No hubo diferencia significativa en las complicaciones globales (32% versus 48%), complicaciones mayores y transfusión. Entre aquellos pacientes de alto riesgo, la trasfusión se realizó en un 13% versus 33% (P = 0,33). CONCLUSIÓN: Se cumplieron los objetivos, pero no se identificó diferencia en EBL en este estudio de factibilidad. Ello justifica un ensayo multicéntrico (PRICE-2) con poder estadístico para identificar una diferencia en la transfusión de sangre perioperatoria.

Elective cesarean delivery in a parturient with Klippel-Feil syndrome.

Klippel-Feil syndrome is defined by congenital fusion of two or more cervical vertebrae and can be associated with abnormalities in multiple systems. Management poses challenges to the anesthesiologist, particularly in pregnancy. Cervical spine immobility and instability can make the management of the airway fraught with danger and vertebral column distortion may make neuraxial anesthesia unreliable. We present the management of a nulliparous patient with features consistent with Type I Klippel-Feil syndrome undergoing elective cesarean delivery. The patient had a potentially difficult airway and features consistent with an unstable cervical spine and severe thoracic and lumbar scoliosis. A combined spinal-epidural technique was used which initially provided satisfactory anesthesia, but ultimately proved inadequate despite use of the epidural component. Satisfactory anesthesia for surgery was eventually achieved with the addition of an intravenous remifentanil infusion. We review previous case reports discussing anesthetic management of parturients with Klippel-Feil syndrome, and describe the challenges encountered and lessons learned from management of this case.

Chemical image fusion. The synergy of FT-NIR and Raman mapping microscopy to enable a more complete visualization of pharmaceutical formulations.

The pharmaceutical industry uses successfully both FT-NIR and Raman microscopy to produce chemical images of solid dosage forms, typically in troubleshooting roles. However, due to the chemical composition of the formulations, it is not always possible to describe the entire chemical formulation by using a single spectroscopic method. As Raman and NIR spectroscopies are complementary in nature, their combined usage offers the opportunity to describe heterogeneous mixtures in more detail. A novel sample referencing approach has been developed that allows data to be acquired from exactly the same area of the sample using both Raman and FT-NIR microscopies. The optimum images for the components are then overlaid, which gives rise to a combined chemical image that visually describes the entire formulation. We have named this approach chemical image fusion (CIF). CIF has been applied to two examples. The first shows how a simple formulation was used to validate the CIF approach. In the second, CIF allowed an entire formulation to be visualized and the cause of tabletting problems determined. CIF provides increased confidence in the results generated by each individual technique and offers a more powerful method for the evaluation of pharmaceutical formulations.

Application of transmission near-infrared spectroscopy to uniformity of content testing of intact steroid tablets.

Transmission near-infrared (NIR) spectroscopy was used for the rapid and non-destructive determination of the content of a hormone steroid in single intact tablets. Tablets produced for clinical trial purposes containing 5, 10, 15, 20 and 30 mg (2.94, 5.88, 8.82, 11.76 and 17.64% m/m, respectively) were used to develop calibration models without the need to specially prepare any out of specification tablets. Reference values for the individual tablets used in the NIR calibration models and test set were measured by reversed-phase high performance liquid chromatography (HPLC). Partial least squares regression using standard normal variate transformed second-derivative spectra over the range 800 to 1040 nm gave the optimum calibration model with a standard error of calibration of 0.52 mg per tablet. Measurements of an independent test set gave comparable results (standard error of prediction 0.31 mg per tablet). Measurement errors for a single tablet (RSD < 2.5% for a given active level) were sufficiently small to allow the procedure to be applied to pharmacopoeial uniformity of content testing of batches of these tablets and permitted the non-destructive testing of 30 tablets in under 20 min as compared to 6 h by HPLC.

Meeting the International Conference on Harmonisation's Guidelines on Validation of Analytical Procedures: quantification as exemplified by a near-infrared reflectance assay of paracetamol in intact tablets.

This Perspective explains how the International Conference on Harmonisation's Guidelines on Validation of Analytical Procedures for quantitative methods can be met by near-infrared (NIR) assays of intact pharmaceutical products. Each of the validation characteristics (accuracy, precision, specificity, detection limit, quantification limit, linearity, range, robustness and system suitability testing) is defined, examined for their relevance to quantitative methods and examples given on how they may be used to demonstrate that near-infrared assays are fit for purpose. Methods for preparing samples for calibration are given in detail. The intention is to provide information so that a pharmaceutical manufacturer could validate a method suitable for an application for a variation of a marketing authorisation for an existing product and use a NIR assay instead of the previous method. The perspective is illustrated in detail using a NIR reflectance assay of paracetamol in intact tablets. This proven assay gives results comparable to the British Pharmacopeia ultraviolet assay for paracetamol, the standard errors of calibration and prediction for the NIR method being 0.48% w/w and 0.71% w/w respectively. The method is also precise, the standard deviation and coefficient of variation for six NIR assays on the same day being 0.14% w/w and 0.16% w/w respectively, while measurements over six consecutive days gave 0.31% w/w and 0.36% w/w respectively.

Non-invasive determination of ethanol, propylene glycol and water in a multi-component pharmaceutical oral liquid by direct measurement through amber plastic bottles using Fourier transform near-infrared spectroscopy.

Fourier transform near-infrared (FT-NIR) spectroscopy was used to quantify rapidly the ethanol (34-49% v/v), propylene glycol (20-35% v/v) and water (11-20% m/m) contents within a multi-component pharmaceutical oral liquid by measurement directly through the amber plastic bottle packaging. Spectra were collected in the range 7302-12,000 cm-1 and calibration models set-up using partial least-squares regression (PLSR) and multiple linear regression. Reference values for the three components were measured using capillary gas chromatography (ethanol and propylene glycol) and Karl Fischer (water) assay procedures. The calibration and test sets consisted of production as well as laboratory batches that were made to extend the concentration ranges beyond the natural production variation. The PLSR models developed gave standard errors of prediction (SEP) of 1.1% v/v for ethanol, 0.9% v/v for propylene glycol and 0.3% m/m for water. For each component the calibration model was validated in terms of: linearity, repeatability, intermediate precision and robustness. All the methods produced statistically favourable outcomes. Ten production batches independent of the calibration and test sets were also challenged against the PLSR models, giving SEP values of 1.3% v/v (ethanol), 1.0% v/v (propylene glycol) and 0.2% m/m (water). NIR transmission spectroscopy allowed all three liquid constituents to be non-invasively measured in under 1 min.

Measurement of the cumulative particle size distribution of microcrystalline cellulose using near infrared reflectance spectroscopy.

The cumulative particle size distribution of microcrystalline cellulose, a widely used pharmaceutical excipient, was determined using near infrared (NIR) reflectance spectroscopy. Forward angle laser light scattering measurements were used to provide reference particle size values corresponding to different quantiles and then used to calibrate the NIR data. Two different chemometric methods, three wavelength multiple linear regression and principal components regression (three components), were compared. For each method, calibration equations were produced at each of eleven quantiles (5, 10, 20, 30, 40, 50, 60, 70, 80, 90, 95%). NIR predicted cumulative frequency particle-size distributions were calculated for each of the calibration samples (n = 34) and for an independent test set (n = 23). The NIR procedure was able to predict those obtained via forward angle laser light scattering.

A rapid quantitative assay of intact paracetamol tablets by reflectance near-infrared spectroscopy.

Near-infrared (NIR) reflectance spectroscopy was used to determine rapidly and non-destructively the content of paracetamol in bulk batches of intact Sterwin 500 mg tablets by collecting NIR spectra in the range 1100-2500 nm and using a multiple linear regression calibration method. The developed NIR method gave results comparable to the British Pharmacopoeia 1993 UV assay procedure, the standard errors of calibration and prediction being 0.48% and 0.71% m/m, respectively. The method showed good repeatability, the standard deviation and coefficient of variation for six NIR assays on the same batch on the same day being 0.14 and 0.16% m/m, respectively, while measurements over six consecutive days gave 0.31 and 0.36% m/m, respectively. Applying the calibration to a parallel test set gave a mean bias of -0.22% and a mean accuracy of 0.45%. The developed method illustrates how the full potential of NIR can be utilised and how the ICH guidelines which recommend the validation of linearity, range, accuracy and precision for pharmaceutical registration purposes can be applied. Duplicate determinations on bulk batches could be performed in under 2 min, allowing the potential use of the method on-line for real time monitoring of a running production process.

Optimisation of sample presentation for the near-infrared spectra of pharmaceutical excipients.

The effects of sample presentation on near-infrared (NIR) reflectance spectra were examined. Using a Foss NIRSystems Rapid Content Analyzer, which uses sample cups for sample presentation, four important parameters were identified: cup diameter, sample thickness, cup material and packing method. Below a critical diameter of 20 mm, which is dependent on the detector geometry, the spectra became increasingly distorted (i.e., changes in spectral intensities and spectral shape, shifts in peak positions and occurrence of Wood's peak). The minimum sample thickness not to cause spectral distortion was dependent on the physical and chemical nature of the substance. A thickness > or = 10 mm was found to be adequate for most pharmaceutical excipients. The method of packing was also important. Tapping a powdered sample sometimes caused significant changes (P < 0.05) in the spectral absorbance values compared with simply pouring the sample into the sample cup. Standard sample cups made from quartz were to be preferred owing to their lack of background absorptivity. However, the two commercially available flat based vials examined, which were made from soda glass and clear neutral glass, proved to be as suitable for all except applications of the most exacting nature. The spectral distortions resulting from variations in cup diameter, sample thickness and cup material were also shown to alter significantly the values of two commonly used identification algorithms, correlation coefficient (< 0.95) and maximum distance (> 3.0 standard deviation distance), sufficiently to cause misidentifications.

Increased levels of a chromosome 21-encoded tumour invasion and metastasis factor (TIAM1) mRNA in bone marrow of Down syndrome children during the acute phase of AML(M7).

Children with Down syndrome (DS) have a 10-20-fold increased risk of acute lymphocytic leukemia (ALL) and acute myeloid leukemia (AML), compared to non-DS children. The myeloid leukemia that accounts for nearly 50% of DS leukemias is usually the otherwise uncommon megakaryoblastic type (AML-M7). Though an etiological role of trisomy 21 in leukemogenesis has been suggested, the expression of genes on chromosome 21 in relation to trisomy, DS, and specific DS phenotypes such as leukemia is poorly understood. We used a heterologous-mimic competitive RT-PCR technique to measure the mRNA levels of a chromosome 21 tumour invasion and metastasis factor (TIAM1) directly in bone marrow samples of DS leukemic patients. In the limited number of cases analysed so far, we found TIAM1 mRNA levels in the DS AML-M7 samples of bone marrow taken in the acute phase of the disease (presentation or relapse, n=8) to be highly significantly raised, nearly threefold, compared to that measured in the remission samples or normal individuals (normals + remissions, n=10).

The application of multiple linear regression to the measurement of the median particle size of drugs and pharmaceutical excipients by near-infrared spectroscopy.

A number of powdered drugs and pharmaceutical excipients were used to demonstrate the ability of near-infrared spectroscopy to measure median particle size (d50). Sieved fractions and bulk samples of aspirin, anhydrous caffeine, paracetamol, lactose monohydrate and microcrystalline cellulose were particle sized by forward angle laser light scattering (FALLS) and scanned by fibre-optic probe FT-NIR spectroscopy. Two-wavenumber multiple linear regression (MLR) calibrations were produced using: NIR reflectance; absorbance and Kubelka-Munk function data with each of median particle size, reciprocal median particle size and the logarithm of median particle size. Best calibrations were obtained using reflectance data versus the logarithm of median particle size (NIR predicted lnd50 versus ln(FALLS d50) for microcrystalline cellulose and lactose monohydrate sieve fraction calibrations: r = 0.99 in each case). Working calibrations for lactose monohydrate (median particle size range: 19.2-183 microns) and microcrystalline cellulose (median particle size range: 24-406 microns) were set-up using combinations of machine sieve-fractions and bulk samples. This approach was found to produce more robust calibrations than just the use of sieved fractions. The method has been compared with single wavenumber quadratic least squares regression using reflectance and mean-corrected reflectance data with median particle size. Correlation between NIR predicted and FALLS values was significantly better using the MLR method.

Quantification of paracetamol in intact tablets using near-infrared transmittance spectroscopy.

Production batch samples of paracetamol tablets and specially prepared out-of-specification batches covering the range 90-110% of the stated amount (500 mg) were analysed by the BP official UV assay and by NIR transmittance spectroscopy. NIR measurements were made on 20 intact tablets from each batch, scanned five times each (10 min measurement time per batch) over the spectral range 6000-11,520 cm-1. An average spectrum was calculated for each batch. Partial least squares (PLS) regression models were set up using a calibration set (20 batches) between the NIR response and the reference tablet paracetamol content (UV). Various pre-treatments of the spectra were examined; the smallest relative standard error of prediction (0.73%) was obtained using the first derivative of the absorbance over the full spectrum. Only two principal components were required for the PLS model to give a good relationship between the spectral information and paracetamol content. Applying this model to the validation set (15 batches) gave a mean bias of -0.08% and a mean accuracy of 0.59% with relative standard deviations of 0.75 and 0.44%, respectively. The proposed method is non-destructive and therefore lends itself to on-line/at-line production control purposes. The method is easy to use and does not require a knowledge of the mass of the tablets.

A quinine a day keeps the leg cramps away?

A double-blind, placebo-controlled, cross-over trial of quinine in leg cramps occurring at rest was conducted in 22 elderly cramp sufferers. Despite demonstration of impaired quinine elimination in the elderly, prescription of the traditional dose of 300 mg quinine bisulphate at night failed to produce a significant (P = 0.1) reduction in the number or severity of cramps. There was a significant relationship between serum quinine concentration and attenuation of cramps. However, the simple expedient of increasing the nightly dose of quinine may carry the concomitant risk of cinchonism.

A.C. polarographic determination of unsaturation.

A wide range of olefins can be determined by a.c. polarography of their addition compounds with mercuric acetate. The first step in the reduction of these compounds is a reversible, one-electron process to form the organo-mercury radical and gives a well defined a.c. peak. The optimum conditions for the determination of a representative selection of olefins has been established.