Diagnostic accuracy comparison between clinical signs and hemoglobin color scale as screening methods in the diagnosis of anemia in children

OBJECTIVES: to compare the validity and reproducibility of clinical signs with the World Health Organization hemoglobin color scale. METHODS: Two hundred six children in the age range of 6-23 months, at the Instituto Materno Infantil Prof. Fernando Figueira, IMIP, were assessed. Two examiners evaluated the clinical signs and the hemoglobin color scale of each child at the different times. The hemoglobin value was used as a standard for validation. RESULTS: in more than 90 percent of cases the agreement between the values of the color scale and the laboratorial hemoglobin was <2 g/dL. Between the clinical signs the highest sensitivity level for diagnosing Hb<11 g/dL was presented by the hemoglobin color scale (75.7 percent). For moderate/severe anemia Hb<9g/dL the highest sensitivity was shown by combined palmar or conjunctival pallor (74.3 percent) and by the color scale (52.5 percent), according to the first and second observer, respectively. The highest specificity level for Hb<11 g/dL was presented by palmar pallor in comparison with the mother's palm and conjunctival pallor (100 percent). For Hb<9 g/dL the highest specificity was presented by the hemoglobin color scale (91.9 percent). CONCLUSIONS: this study suggests that moderate/severe anemia can be diagnosed either by clinical signs or by the color scale, while, in cases of mild anemia, the better diagnosis tool appears to be the color scale.

OBJETIVOS: comparar a validade e reprodutibilidade dos sinais clínicos (palidez palmar e conjuntival) com a escala de cores da hemoglobina da Organização Mundial de Saúde. MÉTODOS: pesquisa realizada em 206 crianças de 6-23 meses, atendidas nos ambulatórios de puericultura e pediatria do Instituto Materno Infantil Prof. Fernando Figueira, IMIP. Os sinais clínicos e a escala de cores da hemoglobina foram avaliados por dois observadores em diferentes momentos. A validação foi realizada utilizando-se a hemoglobina como padrão. RESULTADOS: em mais de 90 por cento dos casos, a concordância entre os valores da escala de cores e da hemoglobina laboratorial encontravam-se em <2 g/dL. Entre os sinais clínicos e a escala de cores, a maior sensibilidade para diagnosticar anemia (Hb<11 g/dL) foi apresentada pela escala de cores da hemoglobina (75,7 por cento) e na anemia moderada/grave (Hb<9 g/dL), pela palidez palmar ou de conjuntiva ocular combinadas (74,3 por cento) e pela escala de cores (52,5 por cento), para o primeiro e segundo examinadores, respectivamente. A maior especificidade foi apresentada na palidez palmar comparada à palma da mãe e palidez de conjuntiva (100 por cento) para Hb<11 g/dL e a escala de cores da hemoglobina (91,9 por cento) para a Hb<9 g/dL. CONCLUSÕES: o presente estudo sugere que o diagnóstico da anemia moderada/grave seja possível através dos sinais clínicos e da escala de cores e, no caso da anemia leve, o melhor instrumento parece ser a escala de cores.

Precisión y exactitud de un oxímetro de pulso "de bolsillo" en la ciudad de México / Precision and accuracy of "a pocket"pulse oximeter in Mexico City

Background. Pulse oximeters are frequently used in the clinical practice and we must known their precision and accuracy. The objective was to evaluate the precision and accuracy of a "pocket" pulse oximeter at an altitude of 2,240 m above sea level. Methods. We tested miniature pulse oximeters (Onyx 9,500, Nonin Finger Pulse Oximeter) in 96 patients sent to the pulmonary laboratory for an arterial blood sample. Patients were tested with 5 pulse oximeters placed in each of the fingers of the hand oposite to that used for the arterial puncture. The gold standard was the oxygen saturation of the arterial blood sample. Results. Blood samples had SaO2 of 87.2 ± 11.0 (between 42.2 and 97.9%). Pulse oximeters had a mean error of 0.28 ± 3.1%. SaO2 - (1.204 x SpO2) - 17.45966 (r = 0.92, p < 0.0001). Intraclass correlation coefficient between each of five pulse oximeters against the arterial blood standard ranged between 0.87 and 0.99. HbCO (2.4 ± 0.6) did not affect the accuracy. Conclusions. The miniature oximeter Nonin is precise and accurate at 2,240 m of altitude. The observed levels of HbCO did not affect the performance of the equipment. The oximeter good performance, small size and low cost enhances its clinical usefulness.

Introducción. Los oxímetros de pulso son ampliamente utilizados en la práctica clínica y su precisión y exactitud deben conocerse especialmente en altitudes moderadas como en la ciudad de México. El objetivo principal fue evaluar la precisión y exactitud de un oxímetro de pulso "de bolsillo" (Onyx 9500 de Nonin®) en la ciudad de México. Métodos. Se realizaron mediciones de la saturación de oxígeno estimada por el oxímetro de pulso (SpO2) y se compararon contra la medida espectrofotométricamente en sangre arterial (SaO2) en 96 pacientes que acudieron al laboratorio de fisiología pulmonar del Instituto Nacional de Enfermedades Respiratorias. A cada paciente se le colocaron cinco oxímetros de pulso en los dedos de una mano obteniéndose un promedio de SpO2 para cada uno de los oxímetros y para los cinco oxímetros a la vez, mediciones que se compararon de manera simultánea contra el estándar. Resultados. Las muestras sanguíneas de los 96 pacientes que participaron tuvieron una SaO2 de 87.2 ± 11.0 (entre 42.2-97.9%). Los oxímetros (promedio de los cinco) tuvieron un error de medición promedio de 0.28 ± 3.1%. SaO2 = (1.204 x SpO2) - 17.45966 (r = 0.92, p < 0.0001). Los coeficientes de correlación intraclase que se obtuvieron al comparar los oxímetros entre sí y contra el estándar (SaO2) estuvieron entre 0.87 y 0.99. El nivel de carboxihemoglobina (HbCO) fue de 2.4 ± 0.6% y no afectó significativamente la exactitud del oxímetro. Conclusiones. El oxímetro digital de pulso "de bolsillo" es preciso y exacto en la estimación de la SaO2 a 2,240 metros de altitud. Los niveles observados de HbCO (2.4%) no afectaron su exactitud. Se observó un adecuado desempeño del oxímetro digital de pulso en la ciudad de México.

Modificação nos níveis de hemoglobina sérica após mamária com TRAM / Modification on serum hemoglobin level after mammary reconstruction with tram

Desde sua introdução por Hartrampf em 1982, o Retalho Músculo Cutâneo Abdominal Tranverso de Músculo Reto do Abdome(TRAM) se tornou um dos elementos de escolha em reconstrução mamária autógena após, ressecção oncológica. Várias comor-bidades têm sido associadas com este procedimento. Os autores realizaram um estudo prospectivo, de uma série de 14 casos de reconstrução de mama com retalhos de TRAM consecutivos, durante o período de 1 ano, tentando estabelecer a mudança na hemoglobina sérica após este tipo de reconstrução. Foi observada uma diminuição na comparação entre a hemoglo-binometria pré-operatória com a pós-operatória (21). Uma expressiva taxa de transfusão sangüínea também foi encontrada (25). Múltiplos fatores, como a seleção dos pacientes, experiência do cirurgião e manejo pré e pós-operatório, podem contribuir para o sucesso de qualquer tipo de reconstrução mamária autógena. Entretanto, este estudo não foi realizado para procurar os fatores que possam causar esta mudança nos níveis de hemoglobina e estudos adicionais devem ser realizados visando identificá-los. Uma importante diminuição do nível de hemoglobina sérica foi estabelecida.

Since its introduction in 1982, the transverse rectus abdominis musculocutaneous (TRAM) flap has become the standard therapy in autogenous breast reconstruction following oncological ressection. Various comorbidities were associated with this procedure. The authors have made a prospective study of a serie of 14 consecutive TRAM flap breast reconstructions during a 1- year period, trying to stabilish the ammount of seric hemoglobin change following this kind of reconstruction It had been observed a decrease when were compared the preoperative and postoperative hemoglobinometry (21). An expressive rate of blood transfusion were also found (25). Multiple factors such as patient selection, surgical expertise, and preoperative and postoperative management may contribute to the success of any type of autogenous breast reconstruction. However, this study were not designed to look for the factors that may cause this level of hemoglobin change, and further studies must be made trying to identify it. An important quantification of the decrease in the seric hemoglobin level were stabilished.

Validation of hemoglobin estimation using Hemocue.

OBJECTIVE: This piece of work is an attempt to compare Hemocue and Cyanmethemoglobin methods for hemoglobin estimation. METHODS: In 100 apparently healthy children of 1-6 years of age, Hb was estimated using Hemocue and cyanmethemoglobin methods from finger prick blood sample. The results obtained by the two methods were compared using appropriate statistical methods. RESULTS: Mean +/- SD values for hemoglobin (g/dl) were 9.33 +/- 2.719 by Hemocue and 8.14 +/- 2.448 by cyanmethemoglobin method. When assessed by Hemocue method the proportion of children with anemia was 66% while it was 88% with cyanmethemoglobin method. The sensitivity of Hemocue method was 0.75 and specificity 1.0 considering cyanmethemoglobin method as gold standard. The corresponding values by cyanmethemoglobin method for a given Hemocue value fell within the Mean difference +/- 2 SD with correlation coefficient being r = 0.922. Despite the good association, the two methods agreed, the magnitude of difference being -1.19 g/dl (CI: -1.40 to -0.98) thus suggesting an overestimate of hemocue values ranging from 10 to 15%. A correction factor was arrived for converting Hb values obtained by Hemocue method to arrive at the expected value by the reference method, this factor being 0.389 + 0.831 Hb (Hemocue). CONCLUSION: As there are limitations expressed for both the methods in accurately estimating Hb, it is difficult to decide whether one is an overestimate or the other an underestimate. By virtue of the principle involved in estimating Hb, cyanmethemoglobin method may be taken as an indirect indicator of iron status. However, it is not clear whether such a principle is involved in estimating Hb by Hemocue. Therefore, these two methods need to be further validated against a sensitive and specific indicator for iron status like circulating transferrin receptor to decide which of the methods can be used to accurately determine the prevalence of iron deficiency anemia in the community.

Correlation between some discrimination functions and hemoglobin E.

The most widely used discriminant functions and red cell indices for differential diagnosis of thalassemia traits from iron deficiency anemia were evaluated for their abilities to identify HbE-containing blood samples. The functions were as follows: F1 = 0.01 x MCH x (MCV)2; F2 = RDW x MCH x (MCV)2/Hb x 100; F3 = MCV/RBC; and F4 = MCH/RBC. Other red cell parameters including RDW, hemoglobin content, mean cell volume, mean cell hemoglobin as well as red cell counts, were also evaluated to distinguish HbE from the normal population. Hemoglobin electrophoresis was used as a confirmatory test. The results showed that F1, F2 and F3 as well as other red cell parameters of HbE-containing samples were different from those of HbA2A-containing red cells although there was no statistical significance. However, F4 and MCHC showed no difference between the two groups. It can be concluded from the present study that identification of hemoglobin E especially the heterozygous form by using parameters from an electronic cell counter is not easy. Discriminant functions and red cell indicies might be used as an initial diagnosis. But confirmation is needed in all cases. Applying the MCV of 80 fl will miss 5 per cent of hemoglobin E carrier but will not miss the homozygous form.

Evaluation of three methods for hemoglobin. Measurement in a blood donor setting

Context: The hemoglobin (HB) level is the most-used parameter for screening blood donors for the presence of anemia, one of the most-used methods for measuring Hb levels is based on photometric detection of cyanmetahemoglobin, as an alternative to this technology, Hemo Cue has developed a photometric method based on the determination of azide metahemoglobin. Objective: To evaluate the performance of three methods for hemoglobin (Hb) determination in a blood bank setting. Design: Prospective study utilizing samples to compare methods for Hb determination. Setting: Hemotherapy Service of the Hospital Israelita Albert Eistein, a private institution in the tertiary health care system. Samples: Seria blood samples were collected from 259 individuals during the period from March to June 1996. Main Measurements: Test performances and their comparisions were assessed by the analysis of coefficients of variation (CV), linear regression and mean differences. Results: The CV for the three methods were: Coulter 0.68 per cent, Cobas 0.82 per cent and Hemo Cue 0.69 per cent. There was no difference between the mean Hb determination for the three methods (p>0.05). The Coulter and Cobas methods showed the best agreement and the HemoCue method gave a lower Hb determination when compared to both the Coulter and Cobas methods. However, paris of methods involving the Hemo Cue seem to have narrower limits of agreement (+0.78 and + 1.02) than the Coulter and Cobas combination (+ 1.13). Conclusion: The three methods provide good agreement for hemoglobin determination.

A simple technique for hemoglobin estimation to screen for anaemia.

Drabkins method has been modified enabling detection of anaemia in a large population. 132 samples of EDTA blood were subjected to hemoglobin estimation by (1) Direct Drabkin (DD) (2), Filter Drabkin (FD) and (3) Special Filter Drabkin (SFD). Hemoglobin estimations by DD and FD compared well on statistical analysis. SFD with a punch diameter of 10.6 to 10.7 mm compared well with DD and is ideal for screening anaemia in field studies.

Comparative study of hemoglobin estimated by Drabkin's and Sahli's methods.

Hemoglobin was estimated by Sahli's and Drabkin's method in samples collected by finger prick and venepuncture. Statistical analysis revealed a significant difference in the hemoglobin values obtained by the two methods (P less than .01 & P less than .05 respectively). Sahli's method carried out by two different groups of workers in samples of blood collected by venepuncture showed statistically significant difference (P less than .001). This could be due to the inbuilt errors of Sahli's method including a subjective bias due to visual comparison. When same samples were subjected to Drabkin's method by the same group of workers no significant difference in the results were obtained (P less than .05). This is due to reliability of the Drabkins method. The aim of this comparative study of hemoglobin estimation by Sahli's and Drabkin's methods is to emphasize the sensitivity and reliability of Drabkin's over Sahli's and utility of Drabkin's method in undergraduate teaching schedule.

Estabilidad de un hemolisado con etilenglicol / Stability of hemolysate with ethyleneglycol

Se estudió el efecto de la temperatura y el tiempo de conservación sobre la concentración de hemoglobina en hemolisados preparados con etilenglicol (EG) o con agua. Se analizó la concentración de hemoglobina en el hemolisado con una probabilidad de 0,95 durante el tiempo de prueba, a diferentes temperaturas. El EG mostró un efecto estabilizador sobre el hemolisado conservado a 4 -C mientras que el preparado con agua se deterioró después de la tercera semana. La concentración de hemoglobina en el hemolisado disminuyó con el tiempo más rápidamente cuanto mayor fue la temperatura de conservación, independientemente del EG o del agua. Los coeficientes de variación durante todo el período de prueba oscilaron entre 0,68 y 1,18