scholarly journals Influence of Measurement Principle on Total Hemoglobin Value

2019 ◽  
Author(s):  
Keisuke Hayashi ◽  
Takashi Hitosugi ◽  
Yoshifumi Kawakubo ◽  
Norihisa Kitamoto ◽  
Takeshi Yokoyama

Abstract Background: Total hemoglobin measurement is indispensable for determining the stroke type (haemorrhagic vs. ischaemic) and need for blood transfusion. Conductivity- and absorbance-based measurement methods are used for blood gas analysis of total hemoglobin. For conductivity-based measurement, total hemoglobin is calculated after converting blood conductivity into a hematocrit value, whereas absorbance measurement is based on light absorbance after red blood cell hemolysis. We previously reported hemolysis observed after infusion or transfusion during veno-arterial extracorporeal membrane oxygenation, and total hemoglobin differed between conductivity and absorbance measurement methods possibly due to plasma electrolyte changes and hemolysis. Methods: In this study, test samples with controlled electrolyte changes and hemolysis were created by adding sodium chloride, distilled water or hemolysed blood to blood samples collected from healthy volunteers, and total hemoglobin values were compared between both methods. Results: Conductivity-based measurement revealed reduced total hemoglobin value (from 15.49 to 13.05 g/dl) following the addition of 10% sodium chloride, which was also reduced by the addition of hemolysate. Conversely, the addition of distilled water significantly increased total hemoglobin value than the expected value. In the absorbance method, there was no significant change in total hemoglobin value due to electrolyte change or hemolysis. Conclusions: The absorbance method should be used when measuring total hemoglobin in patients with expected blood conductivity changes. However, when using this method, the added contribution of hemoglobin from hemolysed erythrocytes lacking oxygen carrying capacity must be considered.

2014 ◽  
Vol 17 (3) ◽  
pp. 154 ◽  
Author(s):  
Arıtürk Cem ◽  
Ustalar Serpil ◽  
Toraman Fevzi ◽  
Ökten Murat ◽  
Güllü Ümit ◽  
...  

<p><strong>Introduction:</strong> Clear guidelines for red cell transfusion during cardiac surgery have not yet been established. The current focus on blood conservation during cardiac surgery has increased the urgency to determine the minimum safe hematocrit for these patients. The aim of this study was to determine whether monitoring of cerebral regional oxygen saturation (rSO<sub>2</sub>) via near-infrared spectrometry (NIRS) is effective for assessing the cerebral effects of severe dilutional anemia during elective coronary arterial bypass graft surgery (CABG).</p><p><strong>Methods:</strong> The prospective observational study involved patients who underwent cerebral rSO<sub>2</sub> monitoring by NIRS during elective isolated first-time CABG: an anemic group (<em>N</em>=15) (minimum Hemoglobin (Hb) N=15) (Hb &gt;8 g/dL during CPB). Mean arterial pressure (MAP), pump blood flow, blood lactate level, pCO<sub>2</sub>, pO<sub>2</sub> at five time points and cross-clamp time, extracorporeal circulation time were recorded for each patient. Group results statistically were compared.</p><p><strong>Results:</strong> The anemic group had significantly lower mean preoperative Hb than the control group (10.3 mg/dL versus 14.2 mg/dL; <em>P</em> = .001). The lowest Hb levels were observed in the hypothermic period of CPB in the anemic group. None of the controls exhibited a &gt;20% decrease in cerebral rSO<sub>2</sub>. Eleven (73.3%) of the anemic patients required an increase in pump blood flow to raise their cerebral rSO<sub>2</sub>.</p><p><strong>Conclusions:</strong> In this study, the changes in cerebral rSO<sub>2</sub> in the patients with low Hb were within acceptable limits, and this was in concordance with the blood lactate levels and blood-gas analysis. It can be suggested that NIRS monitoring of cerebral rSO<sub>2</sub> can assist in decision making related to blood transfusion and dilutional anemia during CPB.</p>


Author(s):  
G.G. Khubulava ◽  
A.B. Naumov ◽  
S.P. Marchenko ◽  
O.Yu. Chupaeva ◽  
A.A. Seliverstova ◽  
...  

Respiration ◽  
2021 ◽  
pp. 1-8
Author(s):  
Clemens F. Hinke ◽  
Rudolf A. Jörres ◽  
Peter Alter ◽  
Robert Bals ◽  
Florian Bornitz ◽  
...  

<b><i>Background:</i></b> Oxygenated hemoglobin(OxyHem) is a simple-to-measure marker of oxygen content capable of predicting all-cause mortality in stable chronic obstructive pulmonary disease (COPD). <b><i>Objectives:</i></b> We aimed to analyze its predictive value during acute exacerbations of COPD (AECOPD). <b><i>Methods:</i></b> In this retrospective study, data from 227 patients discharged after severe AECOPD at RoMed Clinical Center Rosenheim, Germany, between January 2012 and March 2018, was analyzed. OxyHem (hemoglobin concentration [Hb] × fractional SpO<sub>2</sub>, g/dL) was calculated from oxygen saturation measured by pulse oximetry and hemoglobin assessed within 24 h after admission. The follow-up (1.7 ± 1.5 years) covered all-cause mortality, including readmissions for severe AECOPD. <b><i>Results:</i></b> During the follow-up period, 127 patients died, 56 due to AECOPD and 71 due to other reasons. Survivors and non-survivors showed differences in age, FVC % predicted, C-reactive protein, hemoglobin, Cr, Charlson Comorbidity Index (CCI), and OxyHem (<i>p</i> &#x3c; 0.05 each). Significant independent predictors of survival were BMI, Cr or CCI, FEV<sub>1</sub> % predicted or FVC % predicted, Hb, or OxyHem. The predictive value of OxyHem (<i>p</i> = 0.006) was superior to that of Hb or SpO<sub>2</sub> and independent of oxygen supply during blood gas analysis. OxyHem was also predictive when using a cutoff value of 12.1 g/dL identified via receiver operating characteristic curves in analyses including either the CCI (hazard ratio 1.85; 95% CI 1.20, 2.84; <i>p</i> = 0.005) or Cr (2.04; 95% CI 1.35, 3.10; <i>p</i> = 0.001) as covariates. <b><i>Conclusion:</i></b> The concentration of OxyHem provides independent, easy-to-assess information on long-term mortality risk in COPD, even if measured during acute exacerbations. It therefore seems worth to be considered for broader clinical use.


Author(s):  
Elisabetta Colciago ◽  
Simona Fumagalli ◽  
Elena Ciarmoli ◽  
Laura Antolini ◽  
Antonella Nespoli ◽  
...  

Abstract Purpose Delayed cord clamping for at least 60 s is recommended to improve neonatal outcomes. The aim of this study is to evaluate whether there are differences in cord BGA between samples collected after double clamping the cord or without clamping the cord, when blood collection occurs within 60 s from birth in both groups. Methods A cross-sectional study was carried out, collecting data from 6884 high-risk women who were divided into two groups based on the method of cord sampling (clamped vs unclamped). Results There were significant decrease in pH and BE values into unclamped group compared with the clamped group. This difference remained significant when considering pathological blood gas analysis parameters, with a higher percentage of pathological pH or BE values in the unclamped group. Conclusion Samples from the unclamped cord alter the acid–base parameters compared to collection from the clamped cord; however, this difference does not appear to be of clinical relevance. Findings could be due to the large sample size, which allowed to achieve a high power and to investigate very small numerical changes between groups, leading to a statistically significant difference in pH and BE between samples even when we could not appreciate any clinical relevant difference of pH or BE between groups. When blood gas analysis is indicated, the priority should be given to the timing of blood collection to allow reliable results, to assess newborns status at birth and intervene when needed.


1934 ◽  
Vol 104 (1) ◽  
pp. 29-31
Author(s):  
Friedrich Rappaport ◽  
Klara Köck-Molnar

2021 ◽  
pp. 039139882098785
Author(s):  
Lawrence Garrison ◽  
Jeffrey B Riley ◽  
Steve Wysocki ◽  
Jennifer Souai ◽  
Hali Julick

Measurements of transcutaneous carbon dioxide (tcCO2) have been used in multiple venues, such as during procedures utilizing jet ventilation, hyperbaric oxygen therapy, as well as both the adult and neo-natal ICUs. However, tcCO2 measurements have not been validated under conditions which utilize an artificial lung, such cardiopulmonary bypass (CPB). The purpose of this study was to (1) validate the use of tcCO2 using an artificial lung during CPB and (2) identify a location for the sensor that would optimize estimation of PaCO2 when compared to the gold standard of blood gas analysis. tcCO2 measurements ( N = 185) were collected every 30 min during 54 pulsatile CPB procedures. The agreement/differences between the tcCO2 and the PaCO2 were compared by three sensor locations. Compared to the earlobe or the forehead, the submandibular PtcCO2 values agreed best with the PaCO2 and with a median difference of –.03 mmHg (IQR = 5.4, p < 0.001). The small median difference and acceptable IQR support the validity of the tcCO2 measurement. The multiple linear regression model for predicting the agreement between the submandibular tcCO2 and PaCO2 included the SvO2, the oxygenator gas to blood flow ratio, and the native perfusion index ( R2 = 0.699, df = 1, 60; F = 19.1, p < 0.001). Our experience in utilizing tcCO2 during CPB has demonstrated accuracy in estimating PaCO2 when compared to the gold standard arterial blood gas analysis, even during CO2 flooding of the surgical field.


1972 ◽  
Vol 2 (18) ◽  
pp. 997-999
Author(s):  
N. B. Pinkus ◽  
B. MacC. Jones ◽  
L. W. Faulks

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