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OBJECTIVE: Twin pregnancies are at an increased risk of stillbirth compared to singletons. Fetal growth restriction (FGR) is a leading cause of perinatal mortality and morbidity, in both singleton and multiple pregnancies. Whether the contribution of FGR to stillbirth in twin pregnancies differs from that in singletons is yet to be determined. The main aim of this study was to determine the association between FGR and stillbirth in twin compared to singleton pregnancies. The secondary objectives include an assessment of the contribution of FGR to stillbirths, stratified by gestational age at delivery. Furthermore, we aimed to compare the association between FGR and stillbirth in twin pregnancies using the twin-specific versus singleton birthweight charts, stratified by chorionicity. METHODS: This was a cross-sectional study including pregnancies receiving obstetric care and birth at St George's Hospital, London. The exclusion criteria included triplet and higher order pregnancies, those resulting in miscarriage or livebirths at or prior to 23+6 weeks, or had a termination of pregnancy, or with missing data on the gestational age at birth. FGR and small for gestational age (SGA) were defined as birthweight <5th and <10th centile, respectively. While standard logistic regression was used for singleton pregnancies, the association of FGR and SGA designation with stillbirth in twin pregnancies was investigated with mixed-effects logistic regression models. For twin pregnancies, intercepts were allowed to vary for twin pairs to account for inter-twin dependency. Analyses were stratified by gestational age at delivery and chorionicity. RESULTS: The study included 95,342 singleton and 3,576 twin pregnancies. There were 494 (0.52%) stillbirths in singleton and 41 (1.15%) stillbirths in twin pregnancies (17 dichorionic and 24 monochorionic). FGR and SGA were significantly associated with stillbirth in singleton pregnancies, across all gestational ages at delivery (before 32 weeks- SGA: OR 2.36; 95% CI 1.78-3.13, p<0.001 and FGR: OR 2.67; 95% CI 2.02- 3.55, p<0.001; between 32-36 weeks- SGA: OR 2.70; 95% CI 1.71-4.31, p<0.001 and FGR: OR 2.82; 95% CI 1.78- 4.47, p<0.001; above 36 weeks- SGA: OR 3.85; 95% CI 2.83 - 5.21, p<0.001 and FGR: OR 4.43; 95% CI 3.16 - 6.12, p<0.001) A greater proportion of fetuses from twin pregnancies were diagnosed as SGA and FGR when singleton compared to the twin-specific chart was used (48.43% vs. 9.12%, and 36.73% vs. 6.23%, respectively). When stratified by gestational age at delivery, both SGA and FGR determined by the twin-specific charts were associated with significantly increased odds of having a stillbirth for those delivered before 32 weeks (SGA: OR 3.87; 95% CI 1.56-9.50, p=0.003 and FGR: OR 5.26; 95% CI 2.11-13.01, p<0.001), those delivered between 32-36 weeks (SGA: OR 6.67; 95% CI 2.11-20.41, p=0.001 and FGR: OR 9.54; 95% CI 3.01-29.40, p<0.001) and those delivered beyond 36 weeks (SGA: OR 12.68 95% CI 2.47-58,15, p=0.001 and FGR: OR 23.84; 95% CI 4.62-110.25, p<0.001), whereas the association of stillbirth with either SGA or FGR was inconsistent when analysed using singleton charts (before 32 weeks- SGA: p=0.014 and FGR: p=0.005; between 32-36 weeks- SGA: p=0.036 and FGR: p=0.008; above 36 weeks- SGA: p=0.080 and FGR: p=0.063). For dichorionic twins delivered before 32 weeks, the odds of an SGA or FGR fetus having a stillbirth was increased when analysed using twin-specific charts. In contrast, monochorionic twins delivered before 32 weeks showed lower and non-significant associations with stillbirth for both SGA and FGR cases using either twin-specific or singleton charts. In dichorionic twin pregnancies delivered between 32-36 weeks, the OR for stillbirth of SGA using twin birthweight chart was 6.70 (95% CI 0.80-56.46, p=0.059), and using singleton chart was 0.92 (95% CI 0.11-7.71, p=0.934) and statistically non-significant. Similarly, the OR for stillbirth of FGR using twin birthweight chart and singleton chart was 9.59 (95% CI 1.14-81.06, p=0.025), and 1.40 (95% CI 0.17-11.76, p=0.735), respectively. On the other hand, in monochorionic twin pregnancies delivered between 32-36 weeks, the OR for stillbirth of SGA and FGR using twin birthweight chart was 9.37 (95% CI 2.20- 37.72, p=0.001), and 13.55 (95% CI 3.12 - 55.94 p < 0.001) respectively. CONCLUSIONS: Our study demonstrates a significant association between SGA, particularly for FGR, with increased odds of stillbirths in singleton pregnancies across all gestational ages. For twin pregnancies, when twin-specific charts were used, SGA and in particular FGR were associated with a significantly increased risk of stillbirth, across all gestational ages at delivery. This article is protected by copyright. All rights reserved.
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Artificial neural networks (ANN) are a groundbreaking technology massively employed in a plethora of fields. Currently, ANNs are mostly implemented through electronic digital computers, but analog photonic implementations are very interesting mainly because of low power consumption and high bandwidth. We recently demonstrated a photonic neuromorphic computing system based on frequency multiplexing that executes ANNs algorithms as reservoir computing and Extreme Learning Machines. Neuron signals are encoded in the amplitude of the lines of a frequency comb, and neuron interconnections are realized through frequency-domain interference. Here we present an integrated programmable spectral filter designed to manipulate the optical frequency comb in our frequency multiplexing neuromorphic computing platform. The programmable filter controls the attenuation of 16 independent wavelength channels with a 20 GHz spacing. We discuss the design and the results of the chip characterization, and we preliminary demonstrate, through a numerical simulation, that the produced chip is suitable for the envisioned neuromorphic computing application.
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PURPOSE: To assess skull bone thickness from birth to skeletal maturity at different sites to provide a reference for the correct selection of pin type and pin placement according to age. METHODS: 270 children and adolescents (age: 0-17 years) with a normal CT scan obtained at Emergency Department for other medical reasons were included. Skull thickness was measured on the axial plane CT scans at eight different sites of the vault: midline anterior (A) and posterior (P), right and left lateral (L), antero-lateral (AL), postero-lateral (PL). RESULTS: From birth to skeletal maturity, L thickness was increased significantly less (+ 58%) compared with AL (+ 205%), P (+ 233%), PL (+ 247%), and A (+ 269%) thickness (P < 0.01). At the end of growth, the thickest and thinnest points of the vault (absolute value) were found at the P and L measurement sites, respectively (P < 0.01). Children aged < 4 years exhibited the highest variability in AL and PL skull bone thickness, with thickness < 3 mm observed in 85% (64/75 patients) and 92% (69/75 patients) of cases, respectively. CONCLUSION: We recommend that the tip of the pin should not exceed 2-3 mm in children aged < 4, and 4 mm in children aged 4-6 years, to decrease the risk of inner table perforation. After the age of 7 years and 13 years, standard-sized pin tips (5 and 6 mm, respectively) may be safely used. Children aged < 4 years show significant variability in skull thickness, and therefore a CT scan may be required for this particular age group.
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Pinos Ortopédicos , Crânio , Adolescente , Criança , Pré-Escolar , Serviço Hospitalar de Emergência , Humanos , Lactente , Recém-Nascido , Crânio/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
BACKGROUND: Few data are available about the frequency of incisional hernia in an emergency subcostal laparotomy. Our objective is to analyze the incidence of incisional hernia after emergency subcostal laparotomy and evaluate if prophylactic mesh could help prevent it. METHODS: This study is a monocentric retrospective analysis following STROBE guideline statements of all patients who underwent an emergency subcostal laparotomy between January 2011 and July 2017 in our University Hospital. We compared complications and incidence of incisional hernia between patients who received sutures (Group S; N = 203) and patients with prophylactic onlay mesh (Group M; N = 80). A multivariate risk factor analysis of incisional hernia was performed. An incisional hernia-estimated risk calculator equation was created. RESULTS: A total of 283 patients were analyzed. There were 80 patients in Group M and 203 in Group S. In short-term outcomes, length of surgery (213 ± 115 min vs 165 ± 73.3 min, P = 0.001) and hospital stay (16.4 ± 18.7 vs 11.6 days ± 13.4, P = 0.038) were longer in Group M. Long-term follow-up was conducted in 207 patients with a mean follow-up time of 39.3 ± 23 months. Incisional hernia was detected in 29 (19.1%) patients in Group S but in only two (3.8%) patients in Group M (P = 0.008). In the multivariate analysis, a risk factor analysis included wound infection (4.91 HR (2.12-11.4); P < 0.001), previous hernia repair (2.86 HR (1.24-6.61); P = 0.014), and shock (2.64 HR (1.01-6.93); P = 0.048). CONCLUSIONS: The incidence of incisional hernia after emergency subcostal laparotomy is high. Risk factors are wound infection, shock, and previous hernia surgery. The use of prophylactic mesh augmentation was safe and reduced the incidence of incisional hernia.
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Hérnia Incisional/epidemiologia , Laparotomia/efeitos adversos , Telas Cirúrgicas , Idoso , Idoso de 80 Anos ou mais , Emergências , Feminino , Humanos , Incidência , Hérnia Incisional/prevenção & controle , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Técnicas de SuturaRESUMO
In the original article some of the column headings in Tables 1-4 were mislabeled.
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Unfortunately, the author group has been incorrectly listed by the first name instead of the family name in the original publication. The complete correct author group should read as follows.
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Spectral shapes of isolated lines of HCl perturbed by Ar are investigated for the first time using classical molecular dynamics simulations (CMDS). Using reliable intermolecular potentials taken from the literature, these CMDS provide the time evolution of the auto-correlation function of the dipole moment, whose Fourier-Laplace transform leads to the absorption spectrum. In order to test these calculations, room temperature spectra of various lines in the fundamental band of HCl diluted in Ar are measured, in a large pressure range, with a difference-frequency laser spectrometer. Comparisons between measured and calculated spectra show that the CMDS are able to predict the large Dicke narrowing effect on the shape of HCl lines and to satisfactorily reproduce the shapes of HCl spectra at different pressures and for various rotational quantum numbers.
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Background: Chronic back pain is a frequent and disabling health problem. There is evidence that ignorance and erroneous beliefs about chronic low back pain among health professionals interfere in the treatment of people who suffer from it. The Health Care Providers' Pain and Impairment Relationship Scale (HC-PAIRS) has been one of the most used scale to assess these misbeliefs, but no studies have been reported in Latin America. Method: We studied the factorial structure of the HC-PAIRS in health personnel and health sciences university students in two Latin American countries: Colombia (n = 930) and Chile (n = 190). Spain's data was taken of the original study of the Spanish version of the HC-PAIRS (171 Physiotherapy students). Additionally, the measurement invariance of this scale among Chile, Colombia and Spain was evaluated by calculating three nested models: configural, metric and scalar. We used a Confirmatory Factor Analysis (CFA) in both Latin American samples, with Maximum Likelihood Robust (MLR) estimation to estimate the parameters. For the final model in each sample, reliability was assessed with the Composite Reliability (CR) index, and to obtain the proportion of variance explained by the scale the Average Variance Extracted (AVE) was calculated. Results: The one-factor solution shows an acceptable fit in both countries after deleting items 1, 6, and 14. For the resulting scale, the CR value is adequate, but the AVE is low. There is scalar invariance between Chile and Colombia, but not between these two countries and Spain. Conclusions: HC-PAIRS is useful for detecting misconceptions about the relationship between chronic low back pain that would cause health personnel to give wrong recommendations to patients. However, it has psychometric weaknesses, and it is advisable to obtain other evidence of validity.
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We report the design, fabrication and characterization of an integrated frequency discriminator on InP technology for microwave photonic phase modulated links. The optical chip is, to the best of our knowledge, the first reported in an active platform and the first to include the optical detectors. The discriminator, designed as a linear filter in intensity, features preliminary SFDR values the range between 67 and 79 dB.Hz(2/3) for signal frequencies in the range of 5-9 GHz limited, in principle, by the high value of the optical losses arising from the use of several free space coupling devices in our experimental setup. As discussed, these losses can be readily reduced by the use of integrated spot-size converters improving the SFDR by 17.3 dB (84-96 dB.Hz(2/3)). Further increase up to a range of (104-116 dB.Hz(2/3)) is possible by reducing the system noise eliminating the EDFA employed in the setup and using a commercially available laser source providing higher output power and lower relative intensity noise. Other paths for improvement requiring a filter redesign to be linear in the optical field are also discussed.
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Índio/química , Dispositivos Ópticos , Fosfinas/química , Telecomunicações/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Micro-Ondas , Fótons , Integração de SistemasRESUMO
BACKGROUND: Guidelines recommend stepping down inhaled corticosteroids (ICS) in patients with well-controlled asthma. However, no information is available on the index that should be used to predict the outcome of reducing the ICS dose. OBJECTIVE: The aim of this study was to investigate the degree of airway responsiveness to adenosine 5' monophosphate (AMP) as an index for deciding whether to reduce ICS dose. PATIENTS AND METHODS: The study population comprised 70 patients with asthma that was well controlled with ICS. Patients were treated for a 2-week baseline period with their usual dose of ICS. For the following 12 weeks, patients were treated with ICS at half their previous dose. Bronchial challenge with AMP was performed at the end of the baseline period and after 2 weeks of treatment with a reduced dose of ICS. Concentration-response curves were used to show the provocative concentration of AMP causing a 20% fall (PC20) in forced expiratory volume in 1 second (FEV1). RESULTS: A decrease in the PC20 of AMP of at least 1 doubling concentration 2 weeks after reducing the ICS dose was a significant predictor of the failure of dose reduction (P = .0011). In contrast, increased responsiveness to inhaled AMP at baseline did not predict the failure of dose reduction. CONCLUSIONS: Our results suggest that, in patients whose asthma is well controlled with ICS, measurement of the modification in the response to AMP 2 weeks after the dose of ICS was halved is a suitable method for assessing the risk of asthma exacerbation following a reduction in ICS dose.
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Monofosfato de Adenosina/administração & dosagem , Corticosteroides/administração & dosagem , Asma/tratamento farmacológico , Administração por Inalação , Adulto , Asma/fisiopatologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Estudos Retrospectivos , Método Simples-CegoRESUMO
BACKGROUND: Atrial fibrillation (AF) is a common cardiac arrhythmia that is associated with an increased risk of major adverse cardiovascular events (MACE). The main goal was to analyze the links and associations between AF and MACE. METHODS: A multicenter, observational, retrospective, community-based study of a cohort (n = 40,297) of the general population aged 65-95 years between 1 January 2015 and 31 December 2021 without a previous diagnosis of AF or MACE in the Primary Care setting. RESULTS: 2574 people (6.39%) developed a first AF event, resulting in an overall incidence of 8.9/1000 people-years [CI95% 8.6-9.2]. The incidence of MACE among those with AF was 75.1/1000 people-years [CI95% 70.8-79.5], whereas among those without AF, it was 20.6/1000 people-years [CI 95% 20.2-21.1], resulting in a rate ratio of 3.65 [CI 95% 3.43-3.88, p < 0.001]. Besides, the incidence of HF with AF was 40.1 people-years [CI 95% 37.1-43.2], while in the group without AF, it was 8.3 people-years [CI 95% 7.9-8.6, p < 0.001], with a rate ratio of 4.85 [CI 95% 4.45-55.3, p < 0.001]. Before an AF diagnosis, there is already a higher risk of chronic kidney disease, ischemic cardiopathy, and peripheral artery disease. A higher risk of poor nutritional status was detected among those with MACE (49.7% vs. 26.6%, p < 0.001). CONCLUSIONS: AF diagnosis increases the incidence of heart failure fourfold. Additional information is required to establish the connection between AF, major adverse cardiovascular events, and nutritional status.
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The modeling of the shape of H(2)O lines perturbed by N(2) (and air) using the Keilson-Storer (KS) kernel for collision-induced velocity changes is revisited with classical molecular dynamics simulations (CMDS). The latter have been performed for a large number of molecules starting from intermolecular-potential surfaces. Contrary to the assumption made in a previous study [H. Tran, D. Bermejo, J.-L. Domenech, P. Joubert, R. R. Gamache, and J.-M. Hartmann, J. Quant. Spectrosc. Radiat. Transf. 108, 126 (2007)], the results of these CMDS show that the velocity-orientation and -modulus changes statistically occur at the same time scale. This validates the use of a single memory parameter in the Keilson-Storer kernel to describe both the velocity-orientation and -modulus changes. The CMDS results also show that velocity- and rotational state-changing collisions are statistically partially correlated. A partially correlated speed-dependent Keilson-Storer model has thus been used to describe the line-shape. For this, the velocity changes KS kernel parameters have been directly determined from CMDS, while the speed-dependent broadening and shifting coefficients have been calculated with a semi-classical approach. Comparisons between calculated spectra and measurements of several lines of H(2)O broadened by N(2) (and air) in the ν(3) and 2ν(1) + ν(2) + ν(3) bands for a wide range of pressure show very satisfactory agreement. The evolution of non-Voigt effects from Doppler to collisional regimes is also presented and discussed.
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Alprazolam, a benzodiazepine widely used for the treatment of psychiatric disorders, has been aimed to be formulated in a transdermal delivery system (TDS) prototype. A series of TDS prototypes dosed in all cases at 0.35 mg·cm(-2) of alprazolam were prepared as a monolithic drug in adhesive matrix using acrylic pressure-sensitive adhesives (PSA) of acrylate vinyl acetate (Duro-tack(®)). The effects of several permeation enhancers as azone, transcutol, propylene glycol, dodecyl alcohol, decyl alcohol, diethanolamine, N-methyl pyrrolidone and lauric acid were studied. Prototypes have been characterized based on adhesion parameters (peel adhesion and shear adhesion), in vitro human skin permeation and in vitro drug release according to European Pharmacopoeia for the selected prototype. Best results show that a combination of permeation enhancers from different chemical groups is able to provide almost a 33 fold increase in the transdermal alprazolam flux of an aqueous saturated dispersion (from 0.054 ± 0.019 to 1.76 ± 0.21 µg h.cm(-2)). Based on these in vitro flux data, a predictive simulation of the achievable plasmatic levels was performed assuming a constant systemic infusion of drug. In summary, it is possible to obtain a prototype of a TDS of alprazolam with adequate adhesive properties (peel adhesion and shear adhesion) and able to predict sustained therapeutic plasmatic levels.
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Alprazolam/administração & dosagem , Alprazolam/química , Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos/métodos , Absorção Cutânea , Adesivo Transdérmico , Adesivos/química , Administração Cutânea , Alprazolam/farmacocinética , Humanos , Permeabilidade , Pele/metabolismo , Água/químicaRESUMO
A coupler based on silicon spherical microcavities coupled to silicon waveguides for telecom wavelengths is presented. The light scattered by the microcavity is detected and analyzed as a function of the wavelength. The transmittance signal through the waveguide is strongly attenuated (up to 25 dB) at wavelengths corresponding to the Mie resonances of the microcavity. The coupling between the microcavity and the waveguide is experimentally demonstrated and theoretically modeled with the help of FDTD calculations.
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In this Letter, the amplitude and group delay characteristics of coupled resonator optical waveguides apodized through the longitudinal offset technique are presented. The devices have been fabricated in silicon-on-insulator technology employing deep ultraviolet lithography. The structures analyzed consisted of three racetracks resonators uniform (nonapodized) and apodized with the aforementioned technique, showing a delay of 5 ± 3 ps and 4 ± 0.5 ps over 1.6 and 1.4 nm bandwidths, respectively.
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We report the first experimental observation of homonuclear propensity in collisional relaxation of a polyatomic molecule. A pump-probe stimulated Raman setup is used to pump population to a single rotational level of the v(2) = 1 vibrationally excited state in (13)C(12)CD(2) and then monitor the redistribution of the rotational population that has taken place after a fixed delay. The Q-branch of the 2ν(2)-ν(2) band shows a pattern of intensity alternation between the even and the odd rotational components, with the greater intensities always corresponding to the rotational levels with the same parity as the one where all the population was initially deposited. The effect can be explained by the existence of a propensity rule that favors collisional relaxation between rovibrational levels of the same parity.
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D-2-hydroxyacid dehydrogenase (D2-HDH) from Haloferax mediterranei has been overexpressed in Escherichia coli, solubilized in 8 M urea and refolded by rapid dilution. The protein was purified and crystallized by the hanging-drop vapour-diffusion method using ammonium sulfate or PEG 3350 as precipitant. Two crystal forms representing the free enzyme and the nonproductive ternary complex with alpha-ketohexanoic acid and NAD(+) grew under these conditions. Crystals of form I diffracted to beyond 3.0 A resolution and belonged to the monoclinic space group P2(1), with unit-cell parameters a = 66.0, b = 119.6, c = 86.2 A, beta = 96.3 degrees . Crystals of form II diffracted to beyond 2.0 A resolution and belonged to the triclinic space group P1, with unit-cell parameters a = 66.5, b = 75.2, c = 77.6 A, alpha = 109.1, beta = 107.5, gamma = 95.9 degrees. The calculated values for V(M) and analysis of the self-rotation and self-Patterson functions suggest that the asymmetric unit in both crystal forms contains two dimers related by pseudo-translational symmetry.
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Oxirredutases do Álcool/química , Haloferax mediterranei/enzimologia , Cristalização , Cristalografia por Raios XRESUMO
Vaccination has been used extensively for the control and prevention of highly pathogenic avian influenza (HPAI) caused by viruses of the H5N1 subtype in endemically infected countries. The Food and Agriculture Organization views vaccination as a legitimate aid in the control and prevention of infection and disease caused by HPAI viruses but does not see it as a panacea. Vaccination should be used as just one in a number of measures used together to reduce the effect and risk of infection. It will be required for a considerable time in endemically infected countries. The methods used in Vietnam in implementing blanket vaccination against H5N1 HPAI viruses demonstrate the steps that should be considered when introducing vaccination. So far, it has not been possible to determine the precise effect of vaccination in endemically infected countries because it has been used in combination with other measures. Well managed vaccination campaigns will reduce the incidence of infection in poultry and therefore reduce the risk to humans from these viruses. Vaccination was implemented to protect both poultry and humans, with a major goal being to reduce the risk of emergence of a human influenza pandemic virus. Economic analysis of vaccination should focus on cost-effectiveness of proposed strategies. Ex-ante and ex-post evaluation of vaccination campaigns should take into account the benefits generated in the poultry sector and for human health.
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Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza , Influenza Aviária/prevenção & controle , Nações Unidas , Vacinação/métodos , Animais , Variação Antigênica , China , Egito , Doenças Endêmicas/prevenção & controle , Doenças Endêmicas/veterinária , Humanos , Indonésia , Virus da Influenza A Subtipo H5N1/patogenicidade , Vacinas contra Influenza/normas , Aves Domésticas , Vacinação/economia , Vacinação/normas , VietnãRESUMO
Pleural effusion secondary to pleuroperitoneal communication is an unusual complication of continuous ambulatory peritoneal dialysis. Many modalities have been used to diagnosis pleuroperitoneal: pleural fluid analysis, chest X- ray, Tc-99m gammagraphy, computed tomography scan and magnetic resonance image. Some of these procedures are invasive or have a high risk of induced-contrast nephrotoxicity. We present two case reports of pleuroperitoneal leak in two patients on peritoneal dialysis diagnosed with Tc-99m gammagraphy. We conclude that Tc- 99m gammagraphy is a simple, safe, non invasive, low radiation exposure and cost effective method in the assessment and evaluation of complications related to peritoneal dialysis such as pleuroperitoneal leak.
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Diálise Peritoneal/efeitos adversos , Peritônio/diagnóstico por imagem , Derrame Pleural/diagnóstico por imagem , Derrame Pleural/etiologia , Tecnécio , Adulto , Idoso , Diafragma , Feminino , Humanos , CintilografiaRESUMO
OBJECTIVES: To validate the use of a digital blood glucose meter for detecting the presence of spinal fluid during combined spinal-epidural anesthesia in terms of specificity, positive and negative predictive values, and likelihood ratios. PATIENTS AND METHODS: Validation was studied in 30 patients scheduled for surgery under combined spinal-epidural anesthesia. A positive finding, defined as detection of spinal fluid return or aspiration by the epidural or spinal needle, was compared with results of standard reference tests (the pattern of sensory or motor block after administration of the local anesthetic). After locating the epidural space with saline solution, the test was performed and 3 mL of local anesthetic was administered. If no sensory or motor blockade was evident, the test was considered a true negative. Spinal puncture was then performed, the test was repeated, and 2 to 3 mL of local anesthetic was injected. The test was considered a true positive if sensory or motor blockade was evident. These findings entered into the validation analyses. RESULTS: Sensitivity was 100%, specificity 94%, positive predictive value 93%, negative predictive value 100%, the positive likelihood ratio 15.5, and negative likelihood 0. CONCLUSION: Blood glucose meter readings provide a valid quantitative measure for distinguishing spinal fluid from saline solution during combined spinal-epidural anesthesia. The method, which uses a readily available device, is easy to use to rule out the presence of spinal fluid.