Spurious point-of-care lactate elevation in ethylene glycol intoxication: rediscovering a clinical pearl

2021 ◽  
Vol 14 (2) ◽  
pp. e239936
Author(s):  
Laurence Poirier-Blanchette ◽  
Camille Simard ◽  
Blair Carl Schwartz
Keyword(s):  
Lactic Acidosis ◽  
Ethylene Glycol ◽  
Mental Status ◽  
Point Of Care ◽  
Clinical Signs ◽  
Altered Mental Status ◽  
Blood Gas ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Renal Replacement Therapy Initiation

A 76-year-old man was found unresponsive and brought to the emergency department. Initial workup showed profound lactic acidosis on a point-of-care arterial blood gas, without clinical signs of hypoperfusion. Investigations for types A and B lactic acidosis revealed no unifying diagnosis to explain both his altered mental status and profound lactic acidosis. A toxicology workup revealed an increased osmolar gap and an elevated ethylene glycol level. The lactic acidosis and his mental status completely normalised within 8 hours of renal replacement therapy initiation and fomepizole administration. Ethylene glycol metabolites have similar molecular structure with L-lactate. Some blood gas analysers are unable to differentiate them, resulting in an artefactual lactate elevation. Our case highlights the importance of recognising a falsely elevated lactate, which should raise clinical suspicion of ethylene glycol poisoning, as the treatment is time-sensitive to prevent complications and mortality.

scholarly journals Agreement between arterial and capillary pH, pCO2 and lactate in patients in the emergency department

2020 ◽  
Author(s):  
V. Collot ◽  
S. Malinverni ◽  
E. Schweitzer ◽  
J. Haltout ◽  
P. Mols ◽  
...  
Keyword(s):  
Lactic Acidosis ◽  
Sensitivity And Specificity ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Mean Difference ◽  
Blood Gas ◽  
Limits Of Agreement ◽  
Study Objective ◽  
Arterial Blood Gas ◽  
Arterial Blood

AbstractStudy objectiveThe primary objective of the study was a quantitative analysis to assess the mean difference and 95% confidence interval of the difference between capillary and arterial blood gas analyses for pH, pCO2 and lactate. Secondary objective was to measure the sensitivity and specificity of capillary samples to detect altered pH, hypercarbia and lactic acidosis.MethodsAdults admitted to the ED for whom the treating physician deemed necessary an arterial blood gas analysis (BGA) were screened for inclusion. Simultaneous arterial and capillary samples were drawn for BGA. Agreement between the two methods for pH, pCO2 and lactate were studied with Bland-Altman bias plot analysis. Sensitivity, specificity, positive and negative predictive value as well as AUC were calculated for the ability of capillary samples to detect pH values outside normal ranges, hypercarbia and hyperlactatemia.Results197 paired analyses were included in the study. Mean difference for pH, between arterial and capillary BGA was 0.0095, 95% limits of agreement were -0.048 to 0.067. For pCO2, mean difference was -0.3 mmHg, 95% limits of agreement were -8.5 to 7.9 mmHg. Lactate mean difference was -0.93 mmol/L, 95% limits of agreement were -2.7 to 0.8 mmol/L. At a threshold of 7.34 for capillary pH had 98% sensitivity and 97% specificity to detect acidemia; at 45.9 mmHg capillary pCO2 had 89% sensitivity and 96% specificity to detect hypercarbia. Finally at a threshold of 3.5 mmol/L capillary lactate had 66% sensitivity to detect lactic acidosis.ConclusionCapillary measures of pH, pCO2 and lactate can’t replace arterial measurements although there is high concordance between the two methods for pH and pCO2 and moderate concordance for lactate. Capillary blood gas analysis had good accuracy when used as a screening tool to detect altered pH and hypercarbia but insufficient sensitivity and specificity when screening for lactic acidosis.

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

2020 ◽  
Author(s):  
Lukasz Krzych ◽  
Olga Wojnarowicz ◽  
Paweł Ignacy ◽  
Julia Dorniak
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Point Of Care ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas ◽  
Acid Base Balance ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
The Impact

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.

scholarly journals Comparison of time taken to obtain an arterial blood gas result at the bedside using the ProximaTM point of care machine vs. a standard remote arterial blood gas analyser: A randomized controlled trial

2020 ◽  
pp. 175114372097384
Author(s):  
Kay Mitchell ◽  
Karen E Salmon ◽  
David Egbosimba ◽  
Gavin Troughton ◽  
Mike PW Grocott
Keyword(s):  
Point Of Care ◽  
Controlled Trial ◽  
Blood Gas ◽  
Sampling System ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
The Mean ◽  
Time Away ◽  
Mean Time ◽  
Reduced Time

Introduction The ProximaTM point of care (POC) device enables arterial blood gas (ABG) samples to be analysed without the nurse leaving the patient. The benefits of this for work efficiency have not been evaluated. Methods We compared the time taken to obtain an ABG result using ProximaTM versus a standard ABG sampling system. Twenty patients were randomized to ABG sampling using ProximaTM, or a standard ABG system. Nurses were observed performing all ABG sampling episodes for a minimum of 24 hours and no more than 72 hours. Results The mean time taken to obtain a result using ProximaTM was 4:56 (SD = 1:40) minutes compared to 6:31 (SD = 1:53) minutes for the standard ABG technique (p < 0.001). Mean time away from the patient's bedside was 3.07 (SD = 1:17) minutes using the standard system and 0 minutes using ProximaTM (p < 0.001). Conclusions Reduced time for blood gas sampling and avoidance of time away from patients may have significant patient safety and resource management implications, but the clinical and financial significance were not evaluated.

scholarly journals Automatic real-time analysis and interpretation of arterial blood gas sample for Point-of-care testing: Clinical validation

PLoS ONE ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. e0248264
Author(s):  
Sancho Rodríguez-Villar ◽  
Paloma Poza-Hernández ◽  
Sascha Freigang ◽  
Idoia Zubizarreta-Ormazabal ◽  
Daniel Paz-Martín ◽  
...  
Keyword(s):  
Metabolic Acidosis ◽  
Metabolic Alkalosis ◽  
Point Of Care ◽  
Respiratory Acidosis ◽  
Blood Gas ◽  
Acid Base ◽  
Predictive Values ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Global Accuracy

Background Point-of-care arterial blood gas (ABG) is a blood measurement test and a useful diagnostic tool that assists with treatment and therefore improves clinical outcomes. However, numerically reported test results make rapid interpretation difficult or open to interpretation. The arterial blood gas algorithm (ABG-a) is a new digital diagnostics solution that can provide clinicians with real-time interpretation of preliminary data on safety features, oxygenation, acid-base disturbances and renal profile. The main aim of this study was to clinically validate the algorithm against senior experienced clinicians, for acid-base interpretation, in a clinical context. Methods We conducted a prospective international multicentre observational cross-sectional study. 346 sample sets and 64 inpatients eligible for ABG met strict sampling criteria. Agreement was evaluated using Cohen’s kappa index, diagnostic accuracy was evaluated with sensitivity, specificity, efficiency or global accuracy and positive predictive values (PPV) and negative predictive values (NPV) for the prevalence in the study population. Results The concordance rates between the interpretations of the clinicians and the ABG-a for acid-base disorders were an observed global agreement of 84,3% with a Cohen’s kappa coefficient 0.81; 95% CI 0.77 to 0.86; p < 0.001. For detecting accuracy normal acid-base status the algorithm has a sensitivity of 90.0% (95% CI 79.9 to 95.3), a specificity 97.2% (95% CI 94.5 to 98.6) and a global accuracy of 95.9% (95% CI 93.3 to 97.6). For the four simple acid-base disorders, respiratory alkalosis: sensitivity of 91.2 (77.0 to 97.0), a specificity 100.0 (98.8 to 100.0) and global accuracy of 99.1 (97.5 to 99.7); respiratory acidosis: sensitivity of 61.1 (38.6 to 79.7), a specificity of 100.0 (98.8 to 100.0) and global accuracy of 98.0 (95.9 to 99.0); metabolic acidosis: sensitivity of 75.8 (59.0 to 87.2), a specificity of 99.7 (98.2 to 99.9) and a global accuracy of 97.4 (95.1 to 98.6); metabolic alkalosis sensitivity of 72.2 (56.0 to 84.2), a specificity of 95.5 (92.5 to 97.3) and a global accuracy of 93.0 (88.8 to 95.3); the four complex acid-base disorders, respiratory and metabolic alkalosis, respiratory and metabolic acidosis, respiratory alkalosis and metabolic acidosis, respiratory acidosis and metabolic alkalosis, the sensitivity, specificity and global accuracy was also high. For normal acid-base status the algorithm has PPV 87.1 (95% CI 76.6 to 93.3) %, and NPV 97.9 (95% CI 95.4 to 99.0) for a prevalence of 17.4 (95% CI 13.8 to 21.8). For the four-simple acid-base disorders and the four complex acid-base disorders the PPV and NPV were also statistically significant. Conclusions The ABG-a showed very high agreement and diagnostic accuracy with experienced senior clinicians in the acid-base disorders in a clinical context. The method also provides refinement and deep complex analysis at the point-of-care that a clinician could have at the bedside on a day-to-day basis. The ABG-a method could also have the potential to reduce human errors by checking for imminent life-threatening situations, analysing the internal consistency of the results, the oxygenation and renal status of the patient.

scholarly journals Multicenter comparison of three intraoperative hemoglobin trend monitoring methods

2019 ◽  
Vol 34 (5) ◽  
pp. 883-892 ◽  
Author(s):  
Richard L. Applegate II ◽  
Patricia M. Applegate ◽  
Maxime Cannesson ◽  
Prith Peiris ◽  
Beth L. Ladlie ◽  
...  
Keyword(s):  
Point Of Care ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas ◽  
Monitoring Methods ◽  
Arterial Blood Gas ◽  
Trend Monitoring ◽  
Arterial Blood ◽  
Time Required ◽  
Clinical Conditions

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.

scholarly journals Hemogasanalysis Point of Care (EPOC) in Pre-Hospital: The Importance of An Early Diagnosis of Silent Hypoxemia in a Context of Scarce Health-Care Resources.

2021 ◽  
Author(s):  
Sara Montemerani ◽  
Asia Urbanelli ◽  
Silvia Cini ◽  
Giovanni Sbrana ◽  
Thomas Tori ◽  
...  
Keyword(s):  
Point Of Care ◽  
Descriptive Analysis ◽  
Hospital Setting ◽  
Blood Gas Analysis ◽  
Gas Analysis ◽  
Blood Gas ◽  
Walking Test ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Blood Gas Analyzer

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.

Assessing the Use of Portable Blood Gas Measurements (iSTAT Instrument) in Emergency Air Transport

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S14-S15
Author(s):  
Anjana Murali ◽  
Marion Jones ◽  
Frank Guyette ◽  
Sarah Wheeler
Keyword(s):  
Quality Control ◽  
Point Of Care ◽  
Hospital Setting ◽  
Blood Gas ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Significant Difference ◽  
Medical Transport ◽  
Gas Measurements ◽  
Flight Measurements

Abstract Hyper and hypoventilation of patients on ventilators leads to poor outcomes. Traditionally, mechanical ventilation protocols in air medical transport are guided by pulse oximetry (SpO2) and continuous end tidal CO2 (EtCO2), which can lead to over-ventilation of patients. The use of portable blood gas measurements is a desirable adjunct in the air medical transport setting due to the complexity and duration of management of critical patients with only limited, noninvasive monitoring options. Previously, protocols relied on SpO2 and EtCO2 to control ventilator settings during in-flight patient management. The iSTAT is a hand-held point of care device often used in acute hospital setting to obtain arterial blood gas results within minutes using a disposable test cartridge and small specimen size. However, iSTAT use in air medical transport has been limited due to analytical and durability concerns in the uncontrolled helicopter environment. The purpose of this study was to test these concerns including the effects of vibrations on the microfluidic transport of blood in the cartridge, pressure changes at altitude on the processing of the cartridge, and temperature changes on the iSTAT instrument between readings during in-flight use. To ensure accurate inflight testing, we assessed precision and accuracy of inflight blood gas measurements compared to pre- and post- flight measurements on quality control material. Precision of initial instrument verification met the manufacturer’s coefficient of variation (CV) claims (lactate = 3.59%, pH = 0.059%, pCO2 = 4%, pO2 = 3%). Initial accuracy was assessed by instrument comparison. Bias of iSTAT compared to the laboratory radiometer ABL800 instrument was acceptable for clinical use (lactate = -7.95%, pH = -0.041%, pCO2 = 1%, pO2 = -2%). For the majority of tests (pH, pCO2, pO2, HCO3, BE, and SO2) we found no significant differences between inflight absolute values compared to pre- and post- flight measurements by one-way anova (p&gt;0.05), and no significant difference in precision (CV) between in air and pre- and post- flight measurements for both low and high quality control samples. In measuring lactate levels, we found significant differences between inflight absolute values compared to pre- and post- flight measurements (p&lt;0.0001) but these were determined to be clinically insignificant (mean (mmol/L): preflight = 6.87, inflight = 6.77, postflight = 6.69). Vibration and pressure differences in air compared to on land were therefore considered clinically insignificant. To keep the instruments at an operable temperature in flight between readings, we found utility in using an insulated lunch box with additional styrofoam placed in the bottom to prevent heat transfer. Most importantly, improved clinical outcomes from proper ventilation of patients were achieved. The results of this study demonstrate that the iSTAT instrument provides clinically accurate blood gas measurements in air as compared to standard in-hospital use.

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