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Correlation between lactate and pH for all measured samples. (A) Lactate versus pH, both measured on the ABL-735. (B) Lactate measured on the StatStrip versus pH measured on the ABL-735. (C) Lactate measured on the iSTAT-CG4+ versus pH measured on the ABL-735.
Source publication
Objectives:
Lactate is a major parameter in medical decision making. During labor, it is an indicator for fetal acidosis and immediate intervention. In the Emergency Department (ED), rapid analysis of lactate/blood gas is crucial for optimal patient care. Our objectives were to cross-compare-for the first time-two point-of-care testing (POCT) lact...
Context in source publication
Context 1
... in lactate. Currently, the pH is used to identify acidotic newborns, but lactate (measured directly with POCT devices) might be suitable to replace pH [8,10]. Therefore, pH and lactate concentrations were compared, resulting in the following correlations: r 2 ¼ À0.45 for the ABL-735, r 2 ¼ À0.40 for the StatStrip and r 2 ¼ À0.48 for the iSTAT (Figs. 3A-C). These three correlations showed a strong significance (p ...Similar publications
Improved risk stratification and prognosis prediction in sepsis is a critical unmet need. Clinical severity scores and available assays such as blood lactate reflect global illness severity with suboptimal performance, and do not specifically reveal the underlying dysregulation of sepsis. Here, we present prognostic models for 30-day mortality gene...
Citations
... Additionally, the use of point-of-care (POC) lactate meters, which require a significantly smaller sample and provide results in seconds, [16][17][18] could also expedite assessment of neonatal metabolic status. Their use could be particularly beneficial in resourceconstrained settings, as they do not require complex instrumentation or specialized laboratory personnel. ...
Objective:
To examine the relationship between point-of-care (POC) measurement of combined umbilical arterial and venous (CUAV) lactate and umbilical artery (UA) lactate to determine whether POC assessment of this sample could be an alternative screening modality for neonatal acidosis and aid prediction of neonatal morbidity.
Methods:
In this cross-sectional pilot study, UA and CUAV cord blood samples were collected from live, singleton neonates delivered between June and August 2019, at a tertiary care center. UA samples were analyzed for pH and lactate using a blood gas analyzer. CUAV lactate was also assessed on a blood gas analyzer and at the POC. Linear regression was used to determine the correlation between these samples.
Results:
A total of 152 neonates were included. There was a statistically significant correlation between CUAV lactate concentrations and UA lactate concentrations (R2 = 0.744). Additionally, CUAV lactate concentration measured at the POC was significantly correlated with that measured on a traditional blood gas analyzer (R2 = 0.928).
Conclusion:
POC testing of CUAV lactate is reliable and closely correlated with UA lactate concentrations, making POC testing of CUAV lactate a potential screening test for neonatal acidosis. More data are needed to establish standardization of this test relative to its predictive value in clinical neonatal outcomes.
... Bedside point-of-care lactate measurements have been shown to have excellent correlation with lab-reported lactate levels. 27 We included only the first lactate level and clinical impression obtained during any ED visit in the dataset, and for individuals with multiple ED visits during the study period, only the first lactate level and clinical impression of the most recent encounter was included. We excluded patients with a diagnosis of seizure because associated high lactate levels carry a very low mortality risk in that subset and prior lactate research studies have excluded patients with seizures 2,12 ( Figure 1). ...
Introduction:
While numerous studies have found emergency department (ED) lactate levels to be associated with increased in-hospital mortality, little information is available on the role age plays in this association. This study investigates whether age is a necessary variable to consider when using lactate levels as a marker of prognosis and a guide for management decisions in the ED.
Methods:
This was a retrospective cohort study in an urban, tertiary-care teaching hospital. A total of 13,506 lactate levels were obtained over a 4.5-year period. All adult patients who had a lactate level obtained by the treating provider in the ED were screened for inclusion. The main outcome measure was in-hospital mortality using age-adjusted cohorts and expanded lactate thresholds with secondary outcomes comparing mortality based on the primary clinical impression.
Results:
Of the 8796 patients in this analysis, there were 474 (5.4%) deaths. Mortality rates increased with both increasing lactate levels and increasing age. For all ages, mortality rates increased from 2.8% in the less than 2.0 millimoles per liter (mmol/L) lactate level, to 5.6% in the 2.0-2.9 mmol/L lactate level, to 8.0% in the 3.0-3.9 mmol/L lactate level, to 13.9% in the 4.0-4.9 mmol/L lactate level, to 13.7% in the 5.0-5.9 mmol/L lactate level, and to 39.1% in the 6.0 mmol/L or greater lactate level (p <0.0001). Survivors, regardless of age, had a mean lactate level <2.0 whereas non-survivors had mean lactate levels of 6.5, 4.5, and 3.7 mmol/L for age cohorts 18-39, 40-64, and ≥ 65 years, respectively.
Conclusion:
Our findings suggest that although lactate levels can be used as a prognostic tool to risk stratify ED patients, the traditional lactate level thresholds may need to be adjusted to account for varying risk based on age and clinical impressions.
... Previous studies have shown that POC devices are able provide reliable measurements of lactate levels in delivery rooms and emergency departments (ED) [8][9][10]. In the study reported here, we shift the focus to cancer patients who not only have cells producing more lactate but may be receiving treatment making them more susceptible to systemic infections. ...
... The correlation and categorization of BLAC from both testing methods show that POCT can accurately measure blood lactic acid values in cancer patients. This finding is consistent with those from previous studies that have shown that a POC device can provide reliable blood lactic acid measurements in ED and delivery rooms [8][9][10]. The assessment of lactic acid by POCT in cancer patients can timely identify who is at risk for sepsis. ...
IntroductionCancer patients are immunosuppressed and may present to an emergency department with atypical symptoms. In the emergency setting, it is important ascertain rapidly if lactic acid levels are high, either due to sepsis or tumor lysis syndrome, to effectively manage symptoms. Therefore, it is critical to determine the blood lactic acid level to timely identify who is at risk of sepsis and provide early intervention. We have compared blood lactic acid concentrations (BLAC) in cancer patients obtained by point-of-care testing (POCT) and those measured by laboratory analysis in blood samples drawn within a short time of each other.Methods
This was a retrospective study in cancer patients whose BLAC had been determined by POCT and laboratory analysis. Only those patients who had blood withdrawn for both testing methods within a 2-h timeframe were included in the study. Regressions were performed together with an analysis categorizing the BLAC from both testing methods.ResultsA total of 274 patients met the criteria for the study. The BLAC from POCT correlated well with the values from laboratory testing (R = 0.925). Categorization of BLAC showed that 88.32% of the patients had BLAC that directly matched between the two tests; 28 (10.22%) patients had a normal BLAC according to laboratory analysis but a high BLAC on POCT; and four (1.46%) patients had a high BLAC according laboratory analysis but normal BLAC on POCT.Conclusions
There was a high correlation between POCT and laboratory analysis values of BLAC in cancer patients, with the results from both testing methods agreeing 96% of the time. This finding suggests that POCT would suffice in most cases. Importantly, in 2% of the cancer patients who presented emergently, BLAC determined by POCT and laboratory analysis did not agree. Therefore, in subsequent decision-making, we recommend that if sepsis is suspected and BLAC determined by POCT is normal, nucleic acids, proteins, circulating cells, and interleukin-3 levels should also be obtained by POCT to confirm sepsis and/or rule out tumor lysis syndrome in patients with cancer.
... SSX is found to have the lowest bias among bench top blood gas analyzers (BGA) and the lowest inter-device variation [13,16]. In accordance with previous studies, we found that SSX had acceptable reproducibility at clinically relevant lactate levels in cord blood [16,32,33]. The goal of 8% bias based on biological variability was not met and we found a significant negative bias in arterial blood of up to 2.6 mmol/L (low levels −0.79 (−21.1%), ...
Objectives:
Measurement of lactate in fetal blood is used to assess the degree of anaerobic metabolism. The technical difficulties in obtaining enough scalp blood for analysis by a bloodgas-analyzer advocates for the use of a point-of-care device. StatStrip®Xpress™ (SSX) has shown promising properties but needs further evaluation before implementation into fetal surveillance.
Methods:
Arterial/venous umbilical cord blood from 112 newborns were analyzed simultaneously with SSX and the reference method ABL800™. From 321 fetuses with abnormal heart rate scalp blood was sampled and analyzed repeatedly with SSX.
Results:
ABL800™ -lactate ranged from 1.9-13.3 mmol/L in arterial to 1.5-10.2 mmol/L in venous cord blood with excellent correlation to SSX (R2 = 0.95). SSX-values were lower compared to the reference method ranging from -0.79 mmol/L for low values to -1.68 mmol/L for high values. The mean CV for SSX-values in cord respectively scalp blood was: lactate ≤3 mmol/L 7.1% respectively 8.4%; lactate >3 mmol/L 3.8% respectively 6.8%. Repeated measurements of the same sample with SSX where without significant difference in cord/scalp blood (p = 0.11).
Conclusion:
SSX-lactate values were constantly lower but correlated excellent to the reference method. The reproducibility was good for cord and scalp blood. We suggest SSX as an attractive device for measurement of fetal lactate.
... We sampled umbilical cord arterial blood from a segment of cord isolated between clamps analysed lactate concentration within 15 min of each birth using a point-of-care test (Lactate Xpress, Nova Biomedical, Runcorn, UK). The test strips have been reported to show excellent correlation of lactate results with those from a conventional laboratory analyser when tested using umbilical cord blood and also showed low analytical imprecision with a coefficient of variation of 5.5% [5]. Postnatal blood samples from mothers were analysed at the bedside for syphilis, malaria and haemoglobin. ...
Objective:
Birth asphyxia contributes substantially to the burden of intrapartum stillbirth and neonatal mortality in resource limited countries. We investigated clinical correlates and neonatal outcomes of lactate analysis of umbilical arterial cord blood in a large referral maternity unit in Malawi using a point-of-care test (Lactate Xpress, Nova Biomedical, Runcorn, UK) and examined maternal and neonatal characteristics and outcomes.
Results:
There were 389 live births and 12 intrapartum stillbirths during the study. The median umbilical arterial lactate concentration was 3.4 mmol/L (interquartile range 2.6-4.9). Umbilical arterial lactate concentrations among the 45 babies admitted for special neonatal care were above 5 mmol/L in 16/45 (36%) of cases, with no fatality below 13 mmol/L. A positive malaria rapid diagnostic test was associated with hyperlactatemia (p < 0.05). In receiver-operator characteristic (ROC) analysis using a lactate cutoff of 5 mmol/L, areas under the curve were 0.72 (95% CI 0.66-0.79) and 0.64 (95% CI 0.58-0.69) for the Apgar score at 1 and 5 min respectively. This approach can identify safely those newborns that are unlikely to require additional monitoring. Scale-up implementation research in low resource country referral units is needed. The influence of malaria on neonatal hyperlactatemia requires further exploration.
Táto príručka chce predovšetkým pre študentov laboratórnych odborov a pre laboratórnych diagnostikov v praxi, ale aj pre študentov rádiologickej techniky, rádiodiagnostikov, medikov a lekárov prehľadne uviesť, ktoré štatistické postupy (slangovo štatistiky) sú vhodné pre porovnávanie metód merania a ktoré nie sú vhodné, a prečo.
Objective
The objective of this study was to assess the value of prehospital measurement of lactate level in blood for diagnosis of seizures in cases of transient loss of consciousness.
Methods
Between March 2018 and September 2019, prehospital lactate was measured with a point‐of‐care device by the emergency medical services in an area serving a population of 900 000. A total of 383 cases of transient loss of consciousness were identified and categorized as tonic‐clonic seizure (TCS), other seizure, syncope, or other cause, according to the final diagnosis in the electronic medical records system. Receiver operating characteristic curve analyses were used to identify the optimal lactate cut‐off.
Results
A total of 383 cases were included (135 TCS, 42 other seizure, 163 syncope, and 43 other causes). The median lactate level in TCS was 7.0 mmol/L, compared to a median of 2.0 mmol/L in all other cases (P < .001). The area under the curve (AUC) of TCS vs nonepileptic causes was 0.87 (95% confidence interval [CI] 0.83‐0.91). The optimal cut‐off (Youden index, 67.8%) was 4.75 mmol/L, with 79% sensitivity (95% CI 71‐85) and 89% specificity (95% CI 85‐93) for TCS.
Significance
Prehospital lactate can be a valuable tool for identifying seizures in transient loss of consciousness. For acceptable specificity, a higher cut‐off than that previously demonstrated for hospital‐based measurements must be used when values obtained close to the time of the event are interpreted.
Expecting ambulance clinicians to dependably differentiate the life-threatening organ dysfunction caused by sepsis from an inflammatory response to a non-infectious aetiology, relying upon vital signs and a physical examination of the patient alone, must be considered unrealistic. Although lactate measurement has been integrated into numerous prehospital sepsis screening tools, it is not yet measured routinely within UK ambulance services. Research has generally focused on whether handheld point-of-care lactate measurement devices are as accurate as laboratory analysis of venous or arterial samples. The weight of literature has concluded negatively in relation to this. However, there is potential for handheld devices to be used independently to monitor trends in lactate elimination or accumulation to inform decisions on the efficacy of prehospital interventions, or simply to report categorical data in terms of whether lactate levels are elevated or not. This offers UK paramedics the opportunity to improve sepsis care through the enhanced assessment of risk and acuity, the identification of patients with cryptic shock, more aggressive fluid resuscitation and advanced notification to receiving units.
Ingreasingly updated and precise molecular diagnostics is becoming essential in disease identification, treatment and management. Conventional technologies are limited to laboratories, which are expensive, require moderate to great volumes of biological fluids and generally create great discomfort among patients. This review discusses some key features of commercially available point of care (POC) devices, such as time to result, accuracy and imprecision, in several medical and veterinary fields. We searched Pubmed/Medline using the key words ‘‘point" "of" "care" "device", selected papers from 1984 to 2019 on the basis of their content and summarized the features in tables.
Fast tournaround time and overall good reliability, in terms of accuracy and imprecision, were observed for most of POCs included in the research.
POC devices are particularly useful for clinicians since they hold the potential to deliver rapid and accurate results in an inexpensive and less invasive way with an overall improvement of patients' quality of life in terms of time spent at the point-of-care and sample volume withdrawn. These features gain great relevance also in the veterinary practice, where patient's compliace is generally poor, available sample volumes are quite far from human ones and analyses costs are higher.
Background:
Point-of-care lactate devices are used worldwide for intrapartum decision making. Current practice is often based on Lactate Pro (Arkray) but its imminent product discontinuation necessitates determination of an optimal replacement device.
Aims:
To evaluate the performance of Lactate Pro and two other point-of-care devices, Lactate Pro 2 (Arkray) and StatStrip (Nova Biomedical), and to derive scalp lactate cut-offs equivalent to the current intervention trigger of >4.8 mmol/L.
Materials and methods:
Paired umbilical cord arterial and venous blood samples from 109 births were tested on the three point-of-care products (two devices each), cross-compared with the reference method blood gas analyser.
Results:
All brands deviate from the blood gas analyser, with Lactate Pro and StatStrip results consistently lower and Lactate Pro 2 consistently higher. Standard deviation from the blood gas analyser was smallest for StatStrip (0.78 mmol/L, cord artery), and largest for Lactate Pro 2 (1.03 mmol/L, cord artery). Within-brand variation exists and is similar for all brands (mean absolute difference on cord artery 0.23-0.30 mmol/L). Equivalent values to the 4.8 mmol/L intervention threshold based on Lactate Pro are 4.9-5.0 mmol/L for StatStrip and 5.3-5.9 mmol/L for Lactate Pro 2, calculated by receiver-operating characteristic analysis.
Conclusions:
StatStrip appears superior to Lactate Pro 2 to replace the original Lactate Pro. Using StatStrip, the 4.8 mmol/L intervention threshold equivalent was 4.9-5.0 mmol/L. The variation in accuracy of point-of-care lactate devices may exceed the small increments (eg <4.2 mmol/L vs >4.8 mmol/L) that guide obstetric decisions.
