scholarly journals Evaluation of the i-STAT Blood Gas Analysis System in Cardiovascular Surgery

2018 ◽  
Vol 4 (2) ◽  
pp. 35
Author(s):  
Çiğdem Unal Kantekin ◽  
Müjgan Ercan ◽  
Esra Firat Oğuz ◽  
Ertan Demirdaş ◽  
Kıvanç Atılgan ◽  
...  

The aim of this study was toinvestigate the compatibility of the parameters measured with the i-STAT blood gas analyser and the conventional blood gas analyser Rapid Point 500 (Siemens Healthcare Diagnostics, USA) in patients who underwent cardiovascular surgery. This clinical study included fifty patients undergoing coronary artery bypass surgery. Fifty whole blood samples were portioned and measured on the i-STAT and RP500 laboratory analyzers. The compatibility between pH, pCO2, pO2, Hb, Na+, K+, iCa2+ and glucose values was investigated.There was a good correlation of the i-STAT analyser with the RP500 analyser, with the exception Hb and Na+. Also all parameters except for Hb and ionized calcium were found to be within acceptable range in terms of clinical decision limits. It is very important that the point-of-care devices give accurate results as well as quick results. For this reason, we absolutely think that the point of care devices should be subjected to external and internal quality control programs, users should be trained regularly and feedback studies should be done.

1994 ◽  
Vol 40 (1) ◽  
pp. 124-129 ◽  
Author(s):  
R J Wong ◽  
J J Mahoney ◽  
J A Harvey ◽  
A L Van Kessel

Abstract We evaluated a new portable instrument, the PPG StatPal II pH and Blood Gas Analysis System, designed for "point-of-care" measurements of blood gases and pH. Inaccuracy (% of target value) and imprecision (CV%) were assessed by blood tonometry and comparison with a Corning 178. Within-day results for PCO2 inaccuracy and imprecision ranged from 98.2% to 102.9% and 3.3% to 3.9%, respectively; for PO2, these were 95.5% to 102.3% and 2.3% to 3.0%, respectively. Between-day results for PCO2 inaccuracy and imprecision ranged from 99.2% to 99.3% and from 2.9% to 3.2%, respectively; for PO2, the ranges were 96.2% to 98.2% and 2.6% to 3.0%, respectively. Two PCO2 outliers (in 645 samples = 0.3%) were observed. In general, tonometry recovery, measurement stability, and pH bias results for the StatPal II and Corning 178 were comparable. We conclude that the StatPal II performs within acceptable ranges of inaccuracy and imprecision.


Author(s):  
Lukasz Krzych ◽  
Olga Wojnarowicz ◽  
Paweł Ignacy ◽  
Julia Dorniak

Introduction. Reliable results of an arterial blood gas (ABG) analysis are crucial for the implementation of appropriate diagnostics and therapy. We aimed to investigate the differences (Δ) between ABG parameters obtained from point-of-care testing (POCT) and central laboratory (CL) measurements, taking into account the turnaround time (TAT). Materials and methods. A number of 208 paired samples were collected from 54 intensive care unit (ICU) patients. Analyses were performed using Siemens RAPIDPoint 500 Blood Gas System on the samples just after blood retrieval at the ICU and after delivery to the CL. Results. The median TAT was 56 minutes (IQR 39-74). Differences were found for all ABG parameters. Median Δs for acid-base balance ere: ΔpH=0.006 (IQR –0.0070–0.0195), ΔBEef=–0.9 (IQR –2.0–0.4) and HCO3–act=–1.05 (IQR –2.25–0.35). For ventilatory parameters they were: ΔpO2=–8.3 mmHg (IQR –20.9–0.8) and ΔpCO2=–2.2 mmHg (IQR –4.2––0.4). For electrolytes balance the differences were: ΔNa+=1.55 mM/L (IQR 0.10–2.85), ΔK+=–0.120 mM/L (IQR –0.295–0.135) and ΔCl–=1.0 mM/L (IQR –1.0–3.0). Although the Δs might have caused misdiagnosis in 51 samples, Bland-Altman analysis revealed that only for pO2 the difference was of clinical significance (mean: –10.1 mmHg, ±1.96SD –58.5; +38.3). There was an important correlation between TAT and ΔpH (R=0.45, p<0.01) with the safest time delay for proper assessment being less than 39 minutes. Conclusions. Differences between POCT and CL results in ABG analysis may be clinically important and cause misdiagnosis, especially for pO2. POCT should be advised for ABG analysis due to the impact of TAT, which seems to be the most important for the analysis of pH.


2018 ◽  
Vol 29 (1) ◽  
pp. 169-172
Author(s):  
Gian Luca Salvagno ◽  
Davide Demonte ◽  
Giuseppe Lippi

A 51-year old male patient was admitted to the hospital with acute dyspnea and history of chronic asthma. Venous blood was drawn into a 3.0 mL heparinized syringe and delivered to the laboratory for blood gas analysis (GEM Premier 4000, Instrumentation Laboratory), which revealed high potassium value (5.2 mmol/L; reference range on whole blood, 3.5-4.5 mmol/L). This result was unexpected, so that a second venous blood sample was immediately drawn by direct venipuncture into a 3.5 mL lithium-heparin blood tube, and delivered to the laboratory for repeating potassium testing on Cobas 8000 (Roche Diagnostics). The analysis revealed normal plasma potassium (4.6 mmol/L; reference range in plasma, 3.5-5.0 mmol/L) and haemolysis index (5; 0.05 g/L). Due to suspicion of spurious haemolysis, heparinized blood was transferred from syringe into a plastic tube and centrifuged. Potassium and haemolysis index were then measured in this heparinized plasma, confirming high haemolysis index (50; 0.5 g/L) and pseudohyperkalemia (5.5 mmol/L). Investigation of this case revealed that spurious haemolysis was attributable to syringe delivery in direct ice contact for ~15 min. This case emphasizes the importance of avoiding sample transportation in ice and the need of developing point of care analysers equipped with interference indices assessment.


Author(s):  
Barbara D. Minty ◽  
J. F. Nunn

We undertook an external quality control survey of blood-gas analysis in 16 laboratories at 13 hospitals. All samples were prepared in the laboratories under investigation by equilibration of blood or serum with gas mixtures of known composition. pH of serum was measured with no significant bias but with an SD of random error 0·026 pH units, which was almost twice the SD of the reference range (0·015). An acceptable random error (half SD of reference range) was not obtained in a longitudinal internal quality control survey although there were acceptable results for buffer pH in both field and internal surveys. Blood Po2 was measured with no significant bias but with SD of random error 1·38 kPa which reduced to 0·72 kPa by excluding one egregious result. The latter value was just over half of the SD of the reference range (1·2 kPa). Pco2 of blood was also measured without significant bias but with a much smaller SD of random error of 0·28 kPa (by excluding one egregious result), which was again just over half the SD of the reference range (0·51 kPa). Measurements of blood Po2 and Pco2 seem generally acceptable in relation to their respective reference ranges but measurements of pH were unsatisfactory in both internal and external trials.


1976 ◽  
Vol 22 (10) ◽  
pp. 1675-1684 ◽  
Author(s):  
C J Delaney ◽  
E T Leary ◽  
V A Raisys ◽  
M A Kenny

Abstract We have conducted a voluntary, community blood-gas proficiency testing program, with use of tonometered human blood, for 32 analyzers located in 16 laboratories. Instruments initially showed inaccuracies as large as -30.8 to +17.3% for po(2), and -14.0 to +42.9% for pco(2), but inaccuracy and imprecision decreased in most laboratories during the program. For a typical 15-week period, mean group precision (CV) was 4.3 To 5.1% for po(2) from 6.92 to 33.3 Pa (52 to 250 mmHg), and 4.0 to 6.9% for pco(2) from 2.0 to 6.8 Pa (15 to 51 mmHg). This program can detect increasing imprecision or inaccuracy caused by analyzer deterioration, and can identify interlaboratory or interinstrument bias and problems not detected by participant quality-control programs. Participants have used the proficiency information in discussing data quality with clinicians, promoting internal control and maintenance programs, and justifying instrument purchases. We believe that proficiency-testing documentation of variability in blood-gas analysis may help to establish realistic patient-care protocols.


2015 ◽  
Vol 27 (1) ◽  
pp. 104
Author(s):  
P. Fantinato-Neto ◽  
A. T. Zanluchi ◽  
M. M. Yasuoka ◽  
F. J. M. Marchese ◽  
J. R. V. Pimentel ◽  
...  

Offspring derived from artificial reproductive techniques are already known to present several postnatal undesirable phenotypes and clinical disorders. Despite its benefits, cloning by somatic cell nuclear transfer (SCNT) is extremely inefficient. The birth rate in cattle is around 5% of the transferred blastocysts, and ~50% of delivered calves die in the first 48 h. Neonatal respiratory distress is reported to be one of the main causes of such deaths. Veterinary intervention is often needed to promote or improve blood oxygenation, avoiding respiratory acidosis and improving carbon dioxide delivery from blood/lungs to the environment. This study aimed to evaluate a neonatal support therapy over the blood gas and acid-base balance on newborn calves derived from SCNT or AI. Four cloned and 3 AI-derived calves delivered by Caesarean section were used for the experiment. Postnatal therapeutic procedures were comprised 4 doses of 400 mg of intratracheal surfactant every 15 min, 25 mg of oral sildenafil every 8 h for 3 days, and 5 L min–1 intranasal oxygen. Blood collections were performed within 30 min (T0), at 12 (T12), 24 (T24) and 48 (T48) hours after delivery. Blood samples were collected from the caudal auricular artery with a butterfly and a blood gas syringe. Oxygen saturation (sO2), arterial pressure of oxygen (PaO2) and carbon dioxide (PaCO2), pH, and bicarbonate (HCO3–) were evaluated with a portable blood gas analyzer (i-STAT, Abbott Point of Care Inc., Princeton, NJ, USA). Data obtained were submitted to ANOVA (Proc MIXED; SAS/STAT, version 9; SAS Institute Inc., Cary, NC, USA). There were significant differences between groups in blood pH (P = 0.0182) and between groups (P = 0.0281) and time of collection (P = 0.0303) in blood bicarbonate (HCO3–). The AI calves were born with normal pH (7.468 ± 0.033) and the cloned calves were born in acidosis (7.216 ± 0.166). These calves were stabilised in T48 (7.427 ± 0.017) using their own HCO3– that increased over time. Although there were no differences in sO2 (P = 0.4525), PaO2 (P = 0.3086), or PaCO2 (P = 0.2514), sO2 and PaO2 were numerically increased at the same time that PaCO2 decreased in both groups. In the cloned calves, the sO2, PaO2, and PaCO2 at T0 were 61.3 ± 28.6%, 39.8 ± 18.5 mmHg, and 65.8 ± 29.3 mmHg, respectively and reached 90.0 ± 3.4%, 57.7 ± 15.8 mmHg, and 42.0 ± 3.7 mmHg. In the AI calves, T0 blood gas analysis were 79.8 ± 19.4%, 56.1 ± 42.1 mmHg, and 39.1 ± 4.8 mmHg, and at T48 were 89.0 ± 2.6%, 82.3 ± 43.5 mmHg, and 43.0 ± 4.9 mmHg for sO2, PaO2, and PaCO2 respectively. The neonate support therapy improved calves' oxygenation and helped to eliminate the carbon dioxide from the blood. In our experience, the neonatal treatment was essential in supporting the lives of the cloned calves.Funding support was received from FAPESP 2011/19543–9.


2018 ◽  
Vol 164 (5) ◽  
pp. 335-337 ◽  
Author(s):  
Christopher T Lewis ◽  
W L Malein ◽  
I Chesner ◽  
S Clarke

IntroductionMeasurement of physiological parameters in extreme environments is essential to advancing knowledge, prophylaxis and treatment of altitude sickness. Point-of-care testing facilitates investigation in non-specialist and remote settings, as well as becoming increasingly popular at the bedside for real-time results in the clinical environment. Arterialised capillary earlobe blood gases are recommended as a valid alternative to arterial sampling in research. This study aimed to test the feasibility of obtaining and analysing daily earlobe samples at high altitude.MethodsFrom 17 to 24 January 2016, 24 participants on a research expedition to Ecuador underwent daily earlobe blood gas measurements including pH, partial pressure of oxygen and partial pressure of carbon dioxide to 5043 m. Samples were analysed using an Abbott i-STAT blood gas analyser and G3+ cartridges.ResultsDaily measurements were successfully obtained and analysed at the point of care in 23/24 participants and were well tolerated with no adverse events. 12% (27/220) cartridges failed and required repeat sampling.ConclusionsDaily earlobe blood gas analysis using the Abbott i-STAT is feasible in a protected environment at high altitude. Participants and equipment should be kept warm before and during testing. Spare cartridges should be available. This methodology may be useful for both research and therapeutic measurements in remote, rural and wilderness medicine.


2018 ◽  
Vol 56 (11) ◽  
pp. 1886-1896
Author(s):  
Min Duan ◽  
Wei Wang ◽  
Haijian Zhao ◽  
Chuanbao Zhang ◽  
Falin He ◽  
...  

Abstract Background: Internal quality control (IQC) is essential for precision evaluation and continuous quality improvement. This study aims to investigate the IQC status of blood gas analysis (BGA) in clinical laboratories of China from 2014 to 2017. Methods: IQC information on BGA (including pH, pCO2, pO2, Na+, K+, Ca2+, Cl−) was submitted by external quality assessment (EQA) participant laboratories and collected through Clinet-EQA reporting system in March from 2014 to 2017. First, current CVs were compared among different years and measurement systems. Then, percentages of laboratories meeting five allowable imprecision specifications for each analyte were calculated, respectively. Finally, laboratories were divided into different groups based on control rules and frequency to compare their variation trend. Results: The current CVs of BGA were significantly decreasing from 2014 to 2017. pH and pCO2 got the highest pass rates when compared with the minimum imprecision specification, whereas pO2, Na+, K+, Ca2+, Cl− got the highest pass rates when 1/3 TEa imprecision specification applied. The pass rates of pH, pO2, Na+, K+, Ca2+, Cl− were significantly increasing during the 4 years. The comparisons of current CVs among different measurement systems showed that the precision performance of different analytes among different measurement systems had no regular distribution from 2014 to 2017. The analysis of IQC practice indicated great progress and improvement among different years. Conclusions: The imprecision performance of BGA has improved from 2014 to 2017, but the status of imprecision performance in China remains unsatisfying. Therefore, further investigation and continuous improvement measures should be taken.


2021 ◽  
Vol 45 (4-5) ◽  
pp. 193-195
Author(s):  
Martin Möckel ◽  
Peter B. Luppa

Abstract Blood gas analysis at or near the patient’s bedside is a common practice in acute medicine and plays a crucial role in the diagnosis and management of patient’s respiratory status, metabolites, electrolytes, co-oximetry and acid–base balance. Pre-analytical quality aspects of the specimens are getting more and more attention, including the presence of potential interferences. Central laboratories have implemented technologies to detect interferences such as hemolysis, lipidemia or hyperbilirubinemia in blood samples to ensure the highest possible quality in results provided to routine care. However, systematic detection for interference due to hemolysis is currently not in place for blood gas analysis at the point-of-care (POC). To apply hemolysis detection solutions at the central laboratory, but not at the POC for blood gas analysis, is a clear contradiction when novel hemolysis detecting technologies are available. The introduction of a system that systematically detects hemolysis in connection to POC blood gas analysis would be imperative to patient safety and costs associated with potential clinical malpractice (leading to wrong, missing and/or delayed treatment) and would also ensure better compliance to CLSI guidelines and ISO standards, and be beneficial for patient and staff.


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