Laboratory Autoanalyzer Research Articles

Comparison between measurement of sodium and potassium by Blood Gas Analyzer versus Laboratory based Auto-analyzer among critically ill patients in a tertiary care hospital

Background: Electrolytes imbalances can lead to critical life threatening events so immediate and accurate assessmentis needed. There is always a time delay in receiving results from the central laboratory auto analyzer (AA). To overcomethis drawback, arterial blood gas (ABG) analyzer can be used as an alternative to measure electrolytes where resultscan be obtained within two minutes, allowing for prompt management. Methods: This cross-sectional study was carried out on 384 intensive care unit (ICU) patients of Bangladesh Instituteof Research and Rehabilitation in Diabetes, Endocrine and Metabolic disorders (BIRDEM) General Hospital. Theaverage values of sodium and potassium in ABG analyzer and laboratory AA were calculated and then the meandifference or bias was obtained of sodium and potassium measurements analyzed by the two methods. Bland-Altmanplot and Lin’s concordance correlation coefficient (ρc) was used to measure the agreement between the two methods.Test results were considered reliable, if the bias was non-significant and within the United States Clinical LaboratoryImprovement Amendment (US CLIA) criteria (±4 mmol/l for sodium and ±0.5 mmol/l for potassium), 95% limits ofagreement (LOA) were narrow and ρc showed good concordance. Results: The mean difference or bias, 95% LOA and ρc for sodium was -1.2 mmol/l, -11 mmol/l to 8.6 mmol/l and 0.85respectively whereas for potassium this was 0.8 mmol/l, -0.39 to 1.98 mmol/l and 0.63 respectively. The bias for sodiumwas within the US CLIA criteria but not so for potassium. However, the 95% LOA was wide and there was poorconcordance for both the measurement. On account of these differences, correction factor was calculated for sodiumand potassium values. Serum sodium (in mmol/l) was 2.48 + 0.97 x ABG sodium (in mmol/l) and serum potassium (inmmol/l) was 1.18 + 0.89 x ABG potassium (in mmol/l). Conclusion: The sodium and potassium measurements obtained from the ABG analyzer was found to be unreliable.However, a correction factor to the ABG analyzer results could be applied to initiate treatment and then changing themanagement, if required, once laboratory AA reports become available. Bangladesh Crit Care J March 2023; 11 (1): 3-8

Evaluation of the Agreement Between 2 Point-Of-Care Glucometers and a Laboratory Automated Analyzer in North American Raptors.

Blood glucose abnormalities are commonly observed in veterinary medicine. Point-of-care (POC) glucometers provide rapid results, are inexpensive, and require very small sample volumes to measure blood glucose concentrations. Although POC glucometers are used frequently in dogs and cats, there have been few studies evaluating POC glucometers in avian species, none of which include raptors. This study evaluated the agreement between a veterinary POC glucometer, a human POC glucometer, and a benchtop laboratory automated analyzer (auto analyzer) using both plasma and whole blood samples from 50 free-ranging raptors admitted to the University of Illinois Wildlife Medical Clinic (Urbana, IL, USA). The veterinary POC glucometer, when used with plasma and whole blood, and the human POC glucometer, when used with whole blood, were in poor agreement with the laboratory auto analyzer. The human POC glucometer, when used with plasma, was in greatest agreement with the laboratory auto analyzer, meeting the US Food and Drug Administration's accuracy guidelines for "over-the-counter" POC glucometers for use in humans. Based on these results, the use of the Contour Next EZ with plasma samples is the only POC recommended for use in raptors. Further research should focus on assessing the clinical utility of blood glucose measurements when treating various disease processes in raptors and the prognostic value of blood glucose measurements when assessing critically ill raptors.

Comparison of Point of Care Versus Laboratory Autoanalyzer Measurements of Sodium and Potassium Levels in Patients Admitted from the Emergency Department

Electrolyte problems are one of the most common cause of morbidity and mortality in the sick patients coming to the Emergency. Electrolytes measured in central lab usually takes 30-60 minutes or more whereas point of care device can give results within 5 to 10 minutes, however different instruments available and their values varies accordingly. Therefore, this study was done to investigate whether electrolyte i.e. sodium and potassium levels assessed using point of care device and auto analysers were equivalent. Methods: We prospectively studied patients admitted from Emergency Department between January 2021 to October 2021. We had taken 60 paired convenience samples and analysed sodium and potassium levels in point of care device (epoc POC device, Siemens) and in Central Lab Auto Analyser (Siemens Dimension RxL Max Integrated chemistry analyzer or in Johnson & Johnson chemistry analyser model number 51 FS). Statistical method to compare the data included Boxplot view, Regression line, Spearman’s correlation coefficient’s, paired t-test for potassium and Wilcox test for sodium correlation, Regression equation, Deming regression and Bland Altman plots.

Comparison of Arterial Blood Gas Analysis versus Central Laboratory Electrolyte and Hemoglobin Determination in Birat Medical College and Teaching Hospital

Introduction: Electrolyte and hemoglobin measurement are the integral part of management of critically ill patient. There can be a wide variation in the electrolyte and hemoglobin measurement in critically ill patient between arterial blood gas analyzer and central laboratory auto analyzer.
 Objective: To compare the electrolytes (sodium, potassium and chloride) and hemoglobin level measured by arterial blood gas analyzer and laboratory analyzer.
 Methodology: This was a prospective cross-sectional comparative study comparing the electrolytes (sodium, potassium and chloride) and hemoglobin measurement between arterial blood gas analyzer and laboratory auto analyzer. The study included 124 paired blood samples from the patient admitted in intensive care unit of Birat Medical College Teaching Hospital in two months duration. The arterial sample and venous sample for electrolytes and hemoglobin measurement were taken simultaneously or not more than one hour apart and analysis was done by arterial blood gas analyzer and central laboratory auto analyzer accordingly. The values of electrolytes and hemoglobin measured by two different analyzers were finally compared for variation.
 Result: The mean difference calculated for sodium potassium and chloride in ABG machine and Auto-analyzers were 0.57 mmol/l.-0.04mmol/l and 1.71mmol/l respectively. These data were within the acceptable range of United States Clinical Laboratory Improvement Amendments(USCLIA). The mean difference derived for hemoglobin in ABG and Auto-analyzers was 0.16g/dl which was not consistent with the range of United States Clinical Laboratory Improvement Amendments (USCLIA)
 Conclusion: The measurement of electrolyte namely sodium, potassium and chloride in ABG machines and Auto-analyzers of central lab were comparable while hemoglobin was not comparable under the USCLIA guidelines.

Determination of Electrolytes in Critical Illness Patients at Different pH Ranges: Whom Shall We Believe, the Blood Gas Analysis or the Laboratory Autoanalyzer?

Introduction The determination of the electrolytes sodium and potassium is essential in critical care. In daily clinical practice, both the blood gas analyzer (ABG) and the laboratory autoanalyzer (AA) are generally applied. However, there is still uncertainty regarding the convergence of the prementioned assays, and data about the comparability dependent on the pH value are still lacking. Materials and Methods One hundred samples from intensive care unit patients with a range in pH values between 7.20 and 7.49 were evaluated in this retrospective cohort study. All patients suffered an infarct-related cardiogenic shock and were intubated and not under therapeutical hypothermia at the time of blood collection. We used scatter plots to compare different distributions of sodium and potassium values between the methods. Comparability of the analyses was assessed using the Bland–Altmann approach, and intraclass correlations (ICC) as estimates of interrater reliability were calculated. Results The mean potassium level measured on ABG was 4.33 mmol/L (SD 0.48 mmol/L), and the value obtained using the AA was 4.40 mmol/L (SD 0.55 mmol/L). A Bland–Altman comparison for total potassium measurements revealed that the limits of agreement were small (−0.241 to 0.391 mmol/L). Total ICC displayed a very good correlation of 0.949. For sodium, we found average values of 140 mmol/L (SD 5.20 mmol/L) in the AA and 140 mmol/L (SD 5.80 mmol/L) in the ABG assessment. Contrarily, the Bland–Altman comparison for sodium displayed that the 95% limits of agreement were very wide (−5.99 to 6.59 mmol/L) for total measurements as well as in every pH subgroup. Total ICC only reached a value of 0.830. Conclusion Data from our single-center study indicate that urgent and vital decisions based on potassium measurements can be made by trusting the value obtained on the ABG machine irrespective of pH values.

Comparison of Hgb, Htc, Na+, and K+ Levels Measured by Blood Gases Analyzer and Laboratory Auto-Analyzer in Different pH Stages

Comparison of Hgb, Htc, Na+, and K+ Levels Measured by Blood Gases Analyzer and Laboratory Auto-Analyzer in Different pH Stages

Correlation between sodium, potassium, hemoglobin, hematocrit, and glucose values as measured by a laboratory autoanalyzer and a blood gas analyzer

IntroductionBlood gas analyzers can be alternatives to laboratory autoanalyzers for obtaining test results in just a few minutes. We aimed to find out whether the results from blood gas analyzers are reliable when compared to results of core laboratory autoanalyzers. Materials and methodsThis retrospective, single-centered study examined the electronic records of patients admitted to the emergency department of a tertiary care teaching hospital between May 2014 and December 2017. Excluded from the study were patients under 18 years old, those lacking data, those who had any treatment before the laboratory tests, those whose venous gas results were reported more than 30 minutes after the blood sample was taken and for whom any of the laboratory tests were performed at a different time, and recurrent laboratory results from a single patient. ResultsLaboratory results were analyzed from a total of 31,060 patients. The correlation coefficients for sodium, potassium, hemoglobin, hematocrit, and glucose levels measured by a blood gas analyzer and a laboratory autoanalyzer were 0.725, 0.593, 0.982, 0.958, and 0.984, respectively; however, there were no good, acceptable agreement limits for any of the parameters. In addition, these results did not change according to the different pH stages (acidosis, normal pH and alkalosis). ConclusionThe two types of measurements showed a moderate correlation for sodium and potassium levels and a strong correlation for glucose, hemoglobin, and hematocrit levels, but none of the levels had acceptable agreement limits. Clinicians should be aware of the limitations of blood gas analyzer results.

Concordance between point-of-care blood gas analysis and laboratory autoanalyzer in measurement of hemoglobin and electrolytes in critically ill patients.

We tested the hypothesis that the results of the same test performed on point-of-care blood gas analysis (BGA) machine and automatic analyzer (AA) machine in central laboratory have high degree of concordance in critical care patients and that the two test methods could be used interchangeably. We analyzed 9398 matched pairs of BGA and AA results, obtained from 1765 patients. Concentration pairs of the following analytes were assessed: hemoglobin, glucose, sodium, potassium, chloride, and bicarbonate. We determined the agreement using concordance correlation coefficient (CCC) and Bland-Altman analysis. The difference in results was also assessed against the United States Clinical Laboratory Improvement Amendments (US-CLIA) 88 rules. The test results were considered to be interchangeable if they were within the US-CLIA variability criteria and would not alter the clinical management when compared to each other. The median time interval between sampling for BGA and AA in each result pair was 5minutes. The CCC values ranged from 0.89(95% CI 0.89-0.90) for chloride to 0.98(95% CI 0.98-0.99) for hemoglobin. The largest bias was for hemoglobin. The limits of agreement relative to bias were largest for sodium, with 3.4% of readings outside the US-CLIA variation rule. The number of readings outside the US-CLIA acceptable variation was highest for glucose (7.1%) followed by hemoglobin (5.9%) and chloride (5.2%). We conclude that there is moderate to substantial concordance between AA and BGA machines on tests performed in critically ill patients. However, the two tests methods cannot be used interchangeably, except for potassium.

Role of Correction Factor in Minimizing Errors While Calculating Electrolyte Values between Blood-gas Analyzer and Laboratory Autoanalyzer: A Comparative Study.

Aims:Electrolytes are charged elements that play important functions in the body. They are measured by both arterial blood–gas (ABG) analyzers and autoanalyzers (AA). In this study, we tried to find out the correction factor for sodium and potassium to establish the concordance between ABG and AA values.Materials and Methods:We prospectively studied 100 samples of patients, and for validation of the result, we applied our result on 30 patients later. 1.5 ml of blood collected in the 2.0 ml syringe preflushed with heparin and analyzed using blood–gas analyzer (ABG). Another sample was sent, to central laboratory, where serum Na+ and K+ concentrations were analyzed. Means, standard deviations, and coefficients of variation with Karl Pearson's correlation coefficients were found out. Deming regression analysis was performed and Bland–Altman plots were also constructed.Results:The mean sodium and potassium were 130.27 ± 7.85 mmol/L and 3.542 ± 0.76 mmol/L using ABG and 139.28 ± 7.89 mmol/L and 4.196 ± 0.72 mmol/L using AA. Concordance between ABG and AA is done by adding the correction factor: for sodium, correction factor is 9.01, standard error = 1.113, class interval = 6.815–11.205; and for potassium (K+), correction factor is 0.654, standard error = 0.1047, class interval = 0.4475–0.8605.Conclusion:The instrument type and calibration methods differ in different hospitals, so it is important that each center conducts an in-hospital study to know the correction factor before installation of an ABG, and the factor should be used accordingly to minimize all errors.

Comparison of serum sodium levels measured by blood gas analyzer and biochemistry autoanalyzer in patients with hyponatremia, eunatremia, and hypernatremia

BackgroundBlood gas analyzer (BGA) electrolyte measurements are frequently used in emergency departments (EDs) pending biochemistry laboratory autoanalyzer (BLA) results. There is lack of data in the literature in terms of agreement of these 2 measurement methods of sodium. We aimed to comprehensively evaluate the agreement in hyponatremia, eunatremia, and hypernatremia groups. MethodsRetrospectively, adult subjects who presented to ED of a tertiary care teaching hospital and had simultaneous BGA and BLA results were included in the study. Blood pairs were grouped into hyponatremia, eunatremia, and hypernatremia according to BLA results. Agreement of sodium measurements between the methods were evaluated by Bland-Altman plots and Passing and Bablok regression analysis. ResultsA total of 2557 blood pairs (1326 males [51.8%]) were included. Median age of the patients was 66 years (18-103). The numbers of patients with hyponatremia, eunatremia, and hypernatremia were 487 (19%), 1943 (76%), and 127 (5%), respectively. The minimum and maximum serum sodium levels measured by biochemistry analyzer were 106 and 171 mmol/L, respectively. The Pearson linear correlation coefficient between BGA and BLA for sodium measurements were 0.574, 0.358, and 0.562 in hyponatremia, eunatremia, and hypernatremia groups, respectively. The absolute mean difference for the 3 groups was greater than 4 mmol/L. Biochemistry laboratory autoanalyzer tended to measure serum sodium higher than BGA in all sodium groups. Passing and Bablok regression analysis showed significant differences between the 2 methods in all sodium groups. ConclusionThis is the first comprehensive evaluation of agreement between BGA and BLA in distinct sodium groups. Significant differences should be taken into account when these patients are managed in the ED.

Analysis of bias in measurements of potassium, sodium and hemoglobin by an emergency department-based blood gas analyzer relative to hospital laboratory autoanalyzer results.

ObjectiveThe emergency departments (EDs) of Chinese hospitals are gradually being equipped with blood gas machines. These machines, along with the measurement of biochemical markers by the hospital laboratory, facilitate the care of patients with severe conditions who present to the ED. However, discrepancies have been noted between the Arterial Blood Gas (ABG) analyzers in the ED and the hospital laboratory autoanalyzer in relation to electrolyte and hemoglobin measurements. The present study was performed to determine whether the ABG and laboratory measurements of potassium, sodium, and hemoglobin levels are equivalent, and whether ABG analyzer results can be used to guide clinical care before the laboratory results become available.Materials and MethodsStudy power analyses revealed that 200 consecutive patients who presented to our ED would allow this prospective single-center cohort study to detect significant differences between ABG- and laboratory-measured potassium, sodium, and hemoglobin levels. Paired arterial and venous blood samples were collected within 30 minutes. Arterial blood samples were measured in the ED by an ABL 90 FLEX blood gas analyzer. The biochemistry and blood cell counts of the venous samples were measured in the hospital laboratory. The potassium, sodium, and hemoglobin concentrations obtained by both methods were compared by using paired Student’s t-test, Spearman’s correlation, Bland-Altman plots, and Deming regression.ResultsThe mean ABG and laboratory potassium values were 3.77±0.44 and 4.2±0.55, respectively (P<0.0001). The mean ABG and laboratory sodium values were 137.89±5.44 and 140.93±5.50, respectively (P<0.0001). The mean ABG and laboratory Hemoglobin values were 12.28±2.62 and 12.35±2.60, respectively (P = 0.24).ConclusionAlthough there are the statistical difference and acceptable biases between ABG- and laboratory-measured potassium and sodium, the biases do not exceed USCLIA-determined limits. In parallel, there are no statistical differences and biases beyond USCLIA-determined limits between ABG- and laboratory-measured hemoglobin. Therefore, all three variables measured by ABG were reliable.

Comparison of blood gas, electrolyte and metabolite results measured with two different blood gas analyzers and a core laboratory analyzer

Background. Blood gas analyzers (BGAs) are important in assessing and monitoring critically ill patients. However, the random use of BGAs to measure blood gases, electrolytes and metabolites increases the variability in test results. Therefore, this study aimed to investigate the correlation of blood gas, electrolyte and metabolite results measured with two BGAs and a core laboratory analyzer. Methods. A total of 40 arterial blood gas samples were analyzed with two BGAs [(Nova Stat Profile Critical Care Xpress (Nova Biomedical, Waltham, MA, USA) and Siemens Rapidlab 1265 (Siemens Healthcare Diagnostics Inc., Tarrytown, NY, USA)) and a core laboratory analyzer [Olympus AU 2700 autoanalyzer (Beckman-Coulter, Inc., Fullerton, CA, USA)]. The results of pH, pCO2, pO2, SO2, sodium (Na+), potassium (K+), calcium (Ca+ 2), chloride (Cl−), glucose, and lactate were compared by Passing-Bablok regression analysis and Bland-Altman plots. Results. The present study showed that there was negligible variability of blood gases (pCO2, pO2, SO2), K+ and lactate values between the blood gas and core laboratory analyzers. However, the differences in pH were modest, while Na+, Cl−, Ca2+ and glucose showed poor correlation according to the concordance correlation coefficient. Conclusions. BGAs and core laboratory autoanalyzer demonstrated variable performances and not all tests met minimum performance goals. It is important that clinicians and laboratories are aware of the limitations of their assays.

1742 A Comparison of Neonatal Bilirubin Determined by Blood gas Analyzer and auto Analyzer

As high levels of serum bilirubin well known to be toxic to the brain especially preterm neonates, many methods adapted for bilirubin measurement. We evaluated total bedside blood gas analyzer...

Use of a blood gas analyzer and a laboratory autoanalyzer in routine practice to measure electrolytes in intensive care unit patients

BackgroundElectrolyte values are measured in most critically ill intensive care unit (ICU) patients using both an arterial blood gas analyzer (ABG) and a central laboratory auto-analyzer (AA). The aim of the present study was to investigate whether electrolyte levels assessed using an ABG and an AA were equivalent; data on sodium and potassium ion concentrations were examined.MethodsWe retrospectively studied patients hospitalized in the ICU between July and August 2011. Of 1,105 test samples, we identified 84 instances of simultaneous sampling of arterial and venous blood, where both Na+ and K+ levels were measured using a pHOx Stat Profile Plus L blood gas analyzer (Nova Biomedical, Waltham MA, USA) and a Roche Modular P autoanalyzer (Roche Diagnostics, Mannheim, Germany). Statistical measures employed to compare the data included Spearman's correlation coefficients, paired Student’s t-tests, Deming regression analysis, and Bland-Altman plots.ResultsThe mean sodium concentration was 138.1 mmol/L (SD 10.2 mmol/L) using the ABG and 143.0 mmol/L (SD 10.5) using the AA (p < 0.001). The mean potassium level was 3.5 mmol/L (SD 0.9 mmol/L) using the ABG and 3.7 mmol/L (SD 1.0 mmol/L) using the AA (p < 0.001). The extent of inter-analyzer agreement was unacceptable for both K+ and Na+, with biases of 0.150-0.352 and −0.97-10.05 respectively; the associated correlation coefficients were 0.88 and 0.90.ConclusionsWe conclude that the ABG and AA do not yield equivalent Na+ and K+ data. Concordance between ABG and AA should be established prior to introduction of new ABG systems.

Validation and implementation of a new hemoglobinometer for donor screening at Canadian Blood Services

Hemoglobin (Hgb) determination is an essential part of donor qualification. We assessed and implemented a new spectrophotometer for donor Hgb determination. Precision, accuracy, and ease of use were assessed on a prototype DiaSpect analyzer (DiaSpect Medical, GmBH, Sailauf, Germany). A protocol to qualify the analyzer was developed and executed preimplementation. Samples were developed for periodic quality control (QC). Postimplementation performance was assessed based on QC results and trending of deferral rates. Precision was excellent, with a coefficient of variation of 0.53%-1.14% per sample. The correlation coefficient between capillary DiaSpect and venous laboratory autoanalyzer measurements was 0.736. After 169 out of 223 analyzers failed to qualify on our initial protocol, all were successfully qualified with the use of a modified protocol, adjusted to avoid sources of variability. Because commercial controls proved inadequate, in-house samples were developed for periodic QC. Postimplementation, all analyzers had adequate QC results. Deferral rates decreased from 10.1 to 8.1% (p < 0.0001) for female donors and from 0.8 to 0.6% for male donors (p < 0.0001). The system was faster and easier to use compared with our previous two-step process. We successfully implemented a new spectrophotometer, which resulted in greater efficiency, improved ease of use, and decreased deferrals.

Comparison of the point-of-care blood gas analyzer versus the laboratory auto-analyzer for the measurement of electrolytes

BackgroundElectrolyte values are measured both by arterial blood gas (ABG) analyzers and central laboratory auto-analyzers (AA), but a significant time gap exists between the availability of both these results, with the ABG giving faster results than the AA. The authors hypothesized that there is no difference between the results obtained after measurement of electrolytes by the blood gas and auto-analyzers.MethodsAfter approval by the ethics committee, an observational cohort study was conducted in which 200 paired venous and arterial samples from patients admitted to the Medical Intensive Care Unit (ICU) of Apollo Hospital, Hyderabad, India, were analyzed for electrolytes on the ABG machine and the AA. Analyses were done on the ABL555 blood gas analyzer and the Dade Dimension RxL Max, both located in the central laboratory. Statistical analyses were performed using paired Student’s t test.ResultsA total of 200 paired samples were analyzed. The mean ABG sodium value was 131.28 (SD 7.33), and the mean AA sodium value was 136.45 (SD 6.50) (p < 0.001). The mean ABG potassium value was 3.74 (SD 1.92), and the mean AA potassium value was 3.896 (SD 1.848) (p = 0.2679).ConclusionBased on the above analysis, the authors found no significant difference between the potassium values measured by the blood gas machine and the auto-analyzer. However, the difference between the measured sodium was found to be significant. We therefore conclude that critical decisions can be made by trusting the potassium values obtained from the arterial blood gas analysis.

An endoscopic pancreatic function test with cholecystokinin-octapeptide for the diagnosis of chronic pancreatitis

Background & Aims: Current pancreatic function tests are cumbersome and unavailable to the clinical gastroenterologist. We have developed a function test that can be modified to a purely endoscopic collection method (ePFT). The aim of this study was to compare the endoscopic and traditional Dreiling tube collection methods. Methods: Two separate groups of healthy subjects and patients with chronic pancreatitis underwent pancreatic function testing. One group underwent the endoscopic collection method (ePFT). Intravenous cholecystokinin (CCK 40 ng · kg −1 · h −1) was started in preprocedure area. Duodenal fluid was collected with upper endoscope during endoscopy at 30, 40, 50, and 60 minutes during infusion. Another group underwent the traditional Dreiling collection method. Intravenous CCK was started in postprocedure area after endoscopic tube placement. Duodenal fluid was collected at 0, 20, 40, 60, and 80 minutes during infusion. Lipase concentration was determined (IU/L) on laboratory autoanalyzer. Results: Seventy-three patients were studied. Thirty-four underwent endoscopic collection and 39 underwent Dreiling collection. The mean peak lipase concentrations (± standard deviation) for healthy subjects and patients with chronic pancreatitis in the endoscopic collection method group were 1,612,500 ± 556,152 IU/L and 369,594 ± 281,624 IU/L, respectively ( P < 0.001). The mean peak lipase concentrations (± standard deviation) for healthy subjects and patients with chronic pancreatitis in the Dreiling tube collection method group were 1,670,324 ± 786,731 IU/L and 478,956 ± 406,061 IU/L, respectively ( P < 0.001). There was no statistical difference between collection methods at distinguishing healthy subjects and patients with chronic pancreatitis. Receiver operating characteristic curves (ROC) for the endoscopic and Dreiling collection methods were 0.993 (standard error of mean, 0.009) and 0.921 (standard error of mean, 0.041). A lipase concentration cut point of 810,600 IU/L distinguishes healthy subjects from patients with chronic pancreatitis with a sensitivity and specificity of 92% and 95%, respectively. The ePFT was safe, short in duration, minimized costs ($1890 vs. $2659), required small amounts of fluid for analysis (1-3 mL), and eliminated radiation exposure. Conclusions: Analysis of timed endoscopic aspirations of pancreatic juice after hormonal stimulation can distinguish healthy subjects from patients with chronic pancreatitis. This new endoscopic collection method (ePFT) is less cumbersome and more time efficient, when compared to traditional collection methods. The ePFT broadens the availability of function testing to the practicing clinical gastroenterologist.

Cholecystokinin-stimulated peak lipase concentration in duodenal drainage fluid: a new pancreatic function test

OBJECTIVE: Hormonal stimulation with secretin or cholecystokinin (CCK) is the most sensitive means of assessing pancreatic function. Secretin is not available, and current CCK tests are cumbersome, requiring dual tube intubation and marker perfusion techniques. The aim of this study was to test the efficacy of a new CCK-stimulated pancreatic function test measuring peak lipase concentration. METHODS: A Dreiling gastroduodenal tube was inserted to the ligament of Treitz, and fluid was collected on ice for 80 min in four 20-min aliquots. CCK was infused i.v. at a constant rate of 40 ng/kg/h. Gastric aspirations were discarded. Duodenal aspirates were analyzed for volume and enzyme concentration with a clinical laboratory autoanalyzer. RESULTS: Nineteen healthy volunteers and 18 chronic pancreatitis patients were studied. Lipase concentration and secretory volume showed a peak response by 40 min of stimulation, whereas amylase response was variable. The mean peak lipase concentrations (±SEM) for normal volunteers and mild, moderate, and advanced chronic pancreatitis patients were 16.9 ± 1.9, 7.9 ± 1.7, 3.7 ± 1.2, and 2.1 ± 0.6 × 10 5 IU/L, respectively. Lower peak lipase concentrations were significantly associated with more advanced chronic pancreatitis ( p < 0.001). The receiver operating characteristic curve area for all chronic pancreatitis patients was 0.944 (95% CI = 0.825–0.985). A peak lipase concentration of 780,000 IU/L provided a sensitivity and specificity of 0.833 and 0.867, respectively. This CCK test was well tolerated and without complications. CONCLUSIONS: Lipase concentration in duodenal fluid increases nearly 3-fold from baseline after CCK stimulation in healthy volunteers but is markedly reduced in patients with chronic pancreatic disease. Peak lipase concentration is a significant predictor of chronic pancreatitis and correlates with severity of pancreatic disease. Aspiration of duodenal drainage fluid with a Dreiling tube and analysis with a laboratory autoanalyzer are less cumbersome than marker perfusion and back titration techniques. Measurement of enzyme concentration instead of output could lead to the development of an endoscopic or through-the-scope screening method for assessing patients with suspected chronic pancreatitis or chronic abdominal pain.

Cholecystokinin-stimulated peak lipase concentration in duodenal drainage fluid: a new pancreatic function test.

Hormonal stimulation with secretin or cholecystokinin (CCK) is the most sensitive means of assessing pancreatic function. Secretin is not available, and current CCK tests are cumbersome, requiring dual tube intubation and marker perfusion techniques. The aim of this study was to test the efficacy of a new CCK-stimulated pancreatic function test measuring peak lipase concentration. A Dreiling gastroduodenal tube was inserted to the ligament of Treitz, and fluid was collected on ice for 80 min in four 20-min aliquots. CCK was infused i.v. at a constant rate of 40 ng/kg/h. Gastric aspirations were discarded. Duodenal aspirates were analyzed for volume and enzyme concentration with a clinical laboratory autoanalyzer. Nineteen healthy volunteers and 18 chronic pancreatitis patients were studied. Lipase concentration and secretory volume showed a peak response by 40 min of stimulation, whereas amylase response was variable. The mean peak lipase concentrations (+/-SEM) for normal volunteers and mild, moderate, and advanced chronic pancreatitis patients were 16.9+/-1.9, 7.9+/-1.7, 3.7+/-1.2, and 2.1+/-0.6 x 10 5 IU/L, respectively. Lower peak lipase concentrations were significantly associated with more advanced chronic pancreatitis (p < 0.001). The receiver operating characteristic curve area for all chronic pancreatitis patients was 0.944 (95% CI = 0.825-0.985). A peak lipase concentration of 780,000 IU/L provided a sensitivity and specificity of 0.833 and 0.867, respectively. This CCK test was well tolerated and without complications. Lipase concentration in duodenal fluid increases nearly 3-fold from baseline after CCK stimulation in healthy volunteers but is markedly reduced in patients with chronic pancreatic disease. Peak lipase concentration is a significant predictor of chronic pancreatitis and correlates with severity of pancreatic disease. Aspiration of duodenal drainage fluid with a Dreiling tube and analysis with a laboratory autoanalyzer are less cumbersome than marker perfusion and back titration techniques. Measurement of enzyme concentration instead of output could lead to the development of an endoscopic or through-the-scope screening method for assessing patients with suspected chronic pancreatitis or chronic abdominal pain.