scholarly journals Be cautious during the interpretation of arterial blood gas analysis performed outside the intensive care unit

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.

2015 ◽  
Vol 30 (2) ◽  
pp. 438.e1-438.e5 ◽  
Author(s):  
Franziska E. Blum ◽  
Elisa Takalo Lund ◽  
Heather A. Hall ◽  
Allan D. Tachauer ◽  
Edgar G. Chedrawy ◽  
...  

2020 ◽  
Vol 7 (1) ◽  
pp. e000778
Author(s):  
Keir Elmslie James Philip ◽  
Benjamin Bennett ◽  
Silas Fuller ◽  
Bradley Lonergan ◽  
Charles McFadyen ◽  
...  

IntroductionUK guidelines suggest that pulse oximetry, rather than blood gas sampling, is adequate for monitoring of patients with COVID-19 if CO2 retention is not suspected. However, pulse oximetry has impaired accuracy in certain patient groups, and data are lacking on its accuracy in patients with COVID-19 stepping down from intensive care unit (ICU) to non-ICU settings or being transferred to another ICU.MethodsWe assessed the bias, precision and limits of agreement using 90 paired SpO2 and SaO2 from 30 patients (3 paired samples per patient). To assess the agreement between pulse oximetry (SpO2) and arterial blood gas analysis (SaO2) in patients with COVID-19, deemed clinically stable to step down from an ICU to a non-ICU ward, or be transferred to another ICU. This was done to evaluate whether the guidelines were appropriate for our setting.ResultsMean difference between SaO2 and SpO2 (bias) was 0.4%, with an SD of 2.4 (precision). The limits of agreement between SpO2 and SaO2 were as follows: upper limit of 5.2% (95% CI 6.5% to 4.2%) and lower limit of −4.3% (95% CI −3.4% to −5.7%).ConclusionsIn our setting, pulse oximetry showed a level of agreement with SaO2 measurement that was slightly suboptimal, although within acceptable levels for Food and Drug Authority approval, in people with COVID-19 judged clinically ready to step down from ICU to a non-ICU ward, or who were being transferred to another hospital’s ICU. In such patients, SpO2 should be interpreted with caution. Arterial blood gas assessment of SaO2 may still be clinically indicated.


2009 ◽  
Vol 10 (4) ◽  
pp. 279-281 ◽  
Author(s):  
Tim Astles

Anaemia in the critically ill remains a contentious issue. Despite adoption of lower haemoglobin levels as transfusion triggers, many patients on intensive care units (ICUs) still require blood transfusions during their illness. One factor that contributes to the critically ill becoming anaemic is regular phlebotomy. Over a two week period, all blood tests performed on patients in a busy, teaching hospital ICU were surveyed to allow calculation of the total volume of blood that had been taken. On average, 52.4 mL of blood was taken per patient per day, and 366.8 mL per patient per week. The most frequently performed tests were arterial blood gas analyses, performed on average 5.8 times per patient per day (range 0–21 times per day). Arterial blood gas analysis alone accounted for taking of 29 mL of blood per patient per day, ie 203 mL per patient per week. Several methods for reducing the amount of blood taken from ICU patients have been identified and discussed. By implementing some of these simple changes in our institution, it would be possible to reduce the volume of blood taken by 43%.


2019 ◽  
Vol 34 (5) ◽  
pp. 883-892 ◽  
Author(s):  
Richard L. Applegate II ◽  
Patricia M. Applegate ◽  
Maxime Cannesson ◽  
Prith Peiris ◽  
Beth L. Ladlie ◽  
...  

AbstractTransfusion decisions are guided by clinical factors and measured hemoglobin (Hb). Time required for blood sampling and analysis may cause Hb measurement to lag clinical conditions, thus continuous intraoperative Hb trend monitoring may provide useful information. This multicenter study was designed to compare three methods of determining intraoperative Hb changes (trend accuracy) to laboratory determined Hb changes. Adult surgical patients with planned arterial catheterization were studied. With each blood gas analysis performed, pulse cooximetry hemoglobin (SpHb) was recorded, and arterial blood Hb was measured by hematology (tHb), arterial blood gas cooximetry (ABGHb), and point of care (aHQHb) analyzers. Hb change was calculated and trend accuracy assessed by modified Bland–Altman analysis. Secondary measures included Hb measurement change direction agreement. Trend accuracy mean bias (95% limits of agreement; g/dl) for SpHb was 0.10 (− 1.14 to 1.35); for ABGHb was − 0.02 (− 1.06 to 1.02); and for aHQHb was 0.003 (− 0.95 to 0.95). Changes more than ± 0.5 g/dl agreed with tHb changes more than ± 0.25 g/dl in 94.2% (88.9–97.0%) SpHb changes, 98.9% (96.1–99.7%) ABGHb changes and 99.0% (96.4–99.7%) aHQHb changes. Sequential changes in SpHb, ABGHb and aHQHb exceeding ± 0.5 g/dl have similar agreement to the direction but not necessarily the magnitude of sequential tHb change. While Hb blood tests should continue to be used to inform transfusion decisions, intraoperative continuous noninvasive SpHb decreases more than − 0.5 g/dl could be a good indicator of the need to measure tHb.


2021 ◽  
Author(s):  
Sara Montemerani ◽  
Asia Urbanelli ◽  
Silvia Cini ◽  
Giovanni Sbrana ◽  
Thomas Tori ◽  
...  

Abstract IntroductionArterial blood gas (ABG) is a useful diagnostic test in the emergency setting. Thanks to the evolution of miniaturized technologies, it was possible to produce a Point of Care ABG analyzer that extended the use of blood gas analysis even in an out-of-hospital context. In the beginning of 2020, the Emergency Medical Service (EMS) of USL Toscana Sud-Est introduced a Point of Care ABG analyzer to characterize respiratory failure in pre-hospital. The onset of SARS-CoV-2 pandemic made the testing ground much more challenging. However, this situation highlighted the potential utility of the hand-held ABG analyzer for a better identification of silent hypoxemia in SARS-CoV-2 patients in pre-hospital setting.MethodsPrimary endpointEarly identification of cases of silent hypoxemia in pre-hospital setting. In our retrospective observational analysis, we want to understand how many patients with silent hypoxemia the hand-held analyzer detect respect the standard measure of peripherical oxygen saturation (SpO2) at rest with pulse oximeter or respect the 6 minutes walking test.Design and settingWe performed a retrospective descriptive analysis of 48 consecutive SARS-CoV-2 patients who activated the territorial Emergency Medical Service of Arezzo (USL Toscana Sud-Est). We included patients between October and November 2020. Age < 18 and pregnancy were considered exclusion criteria. After the telephone triage, the operations center sent the ALS ambulance with a team made up of a physician and a nurse who performed a clinical evaluation of the patient and an arterial blood gas analysis directly at home. Arterial blood was collected from the patient's radial or brachial artery. ALS team directly visualized the result of the exam on EPOC.ResultsA total of 48 SARS-CoV-2 patients were collected, 28 men and 20 women, respectively. Nineteen of the total amounts of 48 SARS-CoV-2 patients had silent hypoxemia identified with the hospital ABG analyzer (gold standard). They didn’t refer dyspnea or didn’t show increased work of breathing during clinical evaluation. These patients had an arterial blood gas oxygen tension (PaO2) of less than 60 mmHg. EPOC identified 20 cases of silent hypoxemia instead of the 19 identified with the hospital blood gas analyzer (Sensibility 100%, Specificity 97%, VPP 95%, VPN 100% with 95% CI). The pulse oximeter detected 21 cases of silent hypoxemia (Sensibility 100%, Specificity 94%, VPP 89%, VPN 100% with 95% CI). The 6 minutes walking test detected only 11 of the 19 cases of silent hypoxemia because the test was aborted in 5 cases, and it was not performed in other 3 cases.ConclusionFrom this first descriptive analysis, we conclude that hand-held blood gas analyzer is useful in the early identification of silent hypoxemia in COVID-19 patients. The EPOC system is a handheld and wireless solution that provides accurate results in less than one minute after sample introduction at the patient’s side. The portability of this point-of-care tool make it potentially useful in pre-hospital clinical practice.


2018 ◽  
Vol 34 (1-2) ◽  
pp. 44-7
Author(s):  
Taslim S. Soetomenggolo ◽  
Dwi Putro Widodo ◽  
Jimmy Passat ◽  
Sofyan Ismael

We reviewed the results of arterial blood gas analysis in 127 patients with neonatal tetanus on admission, and in 52 of such patients on the day before they died. All patients were hospitalized at the Department of Child Health, Cipto Mangunkusumo Hospital, Jakarta. On admission, most patients showed uncompensated metabolic acidosis. The mortality of patients wjth pH ofless than 7 was 100%. There was no significant difference between the mortality of patients with pH 7.35-7.45 and those with pH of less than 7.35. Analysis of acid-base balance indicated that ventilatory fw1ure was the most common finding in 52 patients who subsequently died. We recommend using intravenous fluid containing a combination of 5% dextrose and sodium bicarbonate with 4 : 1 (vol/vol) ratio from the fust day of hospitalization to reduce the possibility of the development of ongoing metabolic acidosis in patients with neonatal tetanus. Maintaining adequate ventilation is mandatory ln such patients.


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