Lactate In Samples Research Articles

Identification and Quantitative Determination of Lactate Using Optical Spectroscopy-Towards a Noninvasive Tool for Early Recognition of Sepsis.

Uninterrupted monitoring of serum lactate levels is a prerequisite in the critical care of patients prone to sepsis, cardiogenic shock, cardiac arrest, or severe lung disease. Yet there exists no device to continuously measure blood lactate in clinical practice. Optical spectroscopy together with multivariate analysis is proposed as a viable noninvasive tool for estimation of lactate in blood. As an initial step towards this goal, we inspected the plausibility of predicting the concentration of sodium lactate (NaLac) from the UV/visible, near-infrared (NIR), and mid-infrared (MIR) spectra of 37 isotonic phosphate-buffered saline (PBS) samples containing NaLac ranging from 0 to 20 mmol/L. UV/visible (300–800 nm) and NIR (800–2600 nm) spectra of PBS samples were collected using the PerkinElmer Lambda 1050 dual-beam spectrophotometer, while MIR (4000–500 cm−1) spectra were collected using the Spectrum two FTIR spectrometer. Absorption bands in the spectra of all three regions were identified and functional groups were assigned. The concentration of lactate in samples was predicted using the Partial Least-Squares (PLS) regression analysis and leave-one-out cross-validation. The regression analysis showed a correlation coefficient (R2) of 0.926, 0.977, and 0.992 for UV/visible, NIR, and MIR spectra, respectively, between the predicted and reference samples. The RMSECV of UV/visible, NIR, and MIR spectra was 1.59, 0.89, and 0.49 mmol/L, respectively. The results indicate that optical spectroscopy together with multivariate models can achieve a superior technique in assessing lactate concentrations.

Technical note: Effect of delayed analysis of cooled lithium-heparinized whole blood on the stability of ionized calcium, ionized magnesium, sodium, potassium, chloride, glucose, and lactate in samples from dairy cows

The objectives of this study were to describe the stability of bovine whole-blood electrolytes, glucose, and lactate in samples collected in lithium heparin tubes and stored in thermoconductive modules immersed in ice water. A total of 99 Jersey cows (40 first-parity, 18 second-parity, and 41 third-parity or greater cows) from a commercial dairy farm in West Texas were enrolled between June and July 2018. Blood was collected from the jugular vein using a 60-mL polypropylene syringe and equally distributed into 5 spray-dried evacuated lithium heparin tubes. Baseline samples were analyzed within 90 s of collection using a benchtop blood gas analyzer. The remaining 4 tubes were stored in a thermoconductive, passive-temperature-regulating module inside a cooler with ice water. At 30 min and 2, 4, and 8 h post-collection, samples were removed from the temperature-regulating module, gently inverted for 10 s, and analyzed. Repeated-measures models were built to evaluate the effect of time on the stability of ionized Ca (iCa), ionized Mg (iMg), Na, K, Cl, glucose, and lactate. Most of the analytes investigated remained stable up to 8 h under ice water storage conditions before analysis, including iCa, iMg, Cl, glucose, and lactate. However, Na and K were significantly affected by delayed analysis: Na remained stable up to 4 h post-collection, but K was not stable starting at 2 h post-collection. The results of this study are useful in helping future researchers and consultants to recognize acceptable time delays between whole blood collection and processing or analysis for electrolytes, glucose, and lactate.

Lactate Levels As A Prognostic Indicator In Heterogeneous ICU Population

Background: The period course of blood lactate levels could be supportive to evaluate a patient’s response to therapy. Serial blood lactate levels in different groups of acutely ill patients. Methods: A total of 200 patients admitted to ICU with critical illness were randomly selected for the study group, Relevant demographic information, clinical history, clinical and laboratory parameters including diagnosis and length of ICU stay were recorded from each patient. The first sample was taken on admission the other samples was taken on 2 nd , 3 rd and 4 th day of admission. Serial arterial sample lactate measurement was done from the patients to note the initial level, time of maximal level and level at time to normal. Result: In the study population 27.5% belonged to the age group of 40-49 years followed by 24% in the age group 50-59 and 20.5% in 60-69 yrs. 57% patients were males and 43% were females. 20.5% patients expired 34.5% patients had hyperlactatemia during ICU stay out of which 31.9% patients expired. Conclusion: Elevated lactate is encountered in a multitude of clinical presentations. Hyperlactatemia is associated with an in-hospital mortality in a heterogeneous ICU population. Patients with elevated lactate levels predicted in hospital mortality and also normalization of lactate within 6 hours is associated with lower mortality. The observation of a better outcome associated with decreasing blood lactate concentrations was consistent throughout the clinical study. Lactate level is an easily measured laboratory parameter which can provide useful information for the bedside clinician when incorporated into the apt clinical milieu. DOI: 10.21276/AAMS.1743

Metformin-associated lactic acidosis treated with continuous renal replacement therapy

Introduction: Lactic acidosis is an infrequent complicationof metformin therapy for diabetes mellitus. The presence of clinical conditions, such as renal failure, increases the risk of metformin-associated lactic acidosis (MALA). We present a case of lactic acidosis in a patient with diabetes treated with metformin, complicated by acute renal failure in preexisting chronic nephropathy. Case summary: A 70-year-old white male, weighing 77 kg, with diabetes mellitus, coronary heart disease, congestive heart failure (New York Heart Association class III), moderate essential hypertension (stage 2), and renal dysfunction (serum urea, 90 mg/dL; serum creatinine, 1.5 mg/dL; creatinine clearance, 49.8 mL/min/1.73 m2) presented to the emergency department of the General Hospital of Rhodes (Rhodes, Greece), complaining of malaise, respiratory distress, myalgias, disorientation, abdominal discomfort, and increasing somnolence of insidious onset. The patient's regimen included isosorbide mononitrate 60 mg QD, furosemide 40 mg QD, quinapril 20 mg QD, and metformin 850 mg TID. Before this hospitalization, he had received a 2-week course of oral diclofenac sodium 25 mg TID for low back pain. Preliminary laboratory evaluation found leukocytosis (27,300/mm 3), severe renal failure (serum urea, 215 mg/dL; serum creatinine, 7.4 mg/dL; calculated creatinine clearance, 10.1 mL/min/1.73 m2), and a high anion gap metabolic acidosis (pH, 6.95; anion gap, 33 mEq/L) in arterial blood gas analysis. His medical and drug history, the clinical and laboratory findings, and the determination of lactate in samples of plasma (7.8 mEq/L), aroused the suspicion of MALA. The Naranjo algorithm scores for metformin and diclofenac sodium were 6 and 7, respectively. The patient received a single session of bicarbonate-buffered continuous venovenous hemodiafiltration (CWHDF) that lasted 16 hours. Ultimately, he was stabilized, and progressive restoration of acid-base balance and renal function was observed. Discussion: We suspect that lactic acidosis mayhave been related to the use of metformin, the presence of heart and renal failure (contributing to metformin toxicity), and previous use of diclofenac sodium. CVVHDF has an advantage over conventional intermittent hemodialysis in that it corrects acidosis and removes lactate and metformin without risk of hypernatremia or fluid overload. Conclusions: MALA should be strongly suspected in diabetic patients presenting with high anion gap metabolic acidosis and increased serum lactate level. In the case described, prompt recognition of lactic acidosis and early application of bicarbonate-buffered CVVHDF produced successful results.

Cytokines and pediatric open heart surgery with cardiopulmonary bypass.

It is well known that, subsequent to cardiopulmonary bypass, and particularly in children, an inflammatory response within the body can often result in a characteristic syndrome. Recently, it has been suggested that this phenomenon is due to a systemic inflammatory response, with significant involvement of cytokines. With this in mind, we investigated the behavior of tumour necrosis factor-alpha and interleukin-6 during the operative and in the immediate postoperative period in a group of children submitted to open heart surgery. We investigated any possible relation between the levels of these cytokines in the serum and the length of cardiopulmonary bypass, with the serum levels of lactate, and with the extent of use of inotropic drugs in postoperative period. The cytokines were measured in samples withdrawn after induction of anesthesia, after 10 minutes of cardiopulmonary bypass, after re-establishment of circulation, and then 2 and 24 hours after the end of cardiopulmonary bypass. The levels of tumour necrosis factor-alpha and interleukin-6 increased between the beginning and at two hours of the end of cardiopulmonary bypass. There was no correlation between the levels of these cytokines in the serum and the length of cardiopulmonary bypass, although there was a positive relation between levels of interleukin-6 and lactate in samples withdrawn at two hours of the end of bypass, and the measured levels of the cytokines correlated with the extent of inotropic drugs employed in the postoperative period.

Gonadotrophin, total oestrogen and progesterone concentrations in plasma of lactating sows with particular reference to lactational oestrus.

Plasma concentrations of LH, FSH, progesterone and total oestrogens were determined (by radioimmunoassay) throughout late pregnancy and lactation in samples taken by cardiac catheter from 10 Camborough hybrid sows. At 2-3 weeks post partum, 5 were housed individually with their litters (Group I) and 5 grouped with their litters, a boar being introduced 1 day later (Group II). Plasma progesterone fell 1-2 days per partum and oestrogens at parturition, each remaining low in early lactation. Plasma LH was undetectable in most samples in this period, but FSH fell slightly during parturition, showing signs of resurgence from Day 10 post partum. Group I sows remained in lactational anoestrus until weaning. In Group II there was increased plasma LH activity, and all Group II sows displayed oestrus during lactation. Only one farrowed to service at the lactational oestrus; of the remainder, oestrus in one was clearly anovulatory, and in two others was incomplete or atypical judged by plasma progesterone concentrations. The data suggest that whilst oestrus can be induced by appropriate lactation management, poor conception rates to service at this oestrus may be due to the absence or impairment of ovulation.

The metabolism of monosaccharides in isolated rat mast cells and its influence on histamine release induced by adenosine-5'-triphosphate.

AbstractHistamine release from isolated rat mast cells induced by extracellularly applied ATP in the presence of calcium was enhanced by D(+)glucose and D(+)mannose, but not by D(‐)‐fructose or D(+) galactose (0.6 mM of each). Only those monosaccharides which enhanced the histamine release were metabolized by the mast cells through the Embden‐Meyerhof pathway as judged from the accumulation of lactate in samples incubated with the sugars. Lactate (1 mM) as well as pyruvate (1 mM) also enhanced the histamine release induced by ATP. Antimycin A (10‐7M) completely inhibited ATP‐induced histamine release irrespectively of the presence of glucose, pyruvate or lactate. Iodoacetate (10‐4M) blocked the enhancing effect of glucose, but not that of pyruvate or lactate. In the presence of glucose (0.6 mM) or mannose (0.6 mM) the accumulation of lactate in suspensions of rat mast cells was enhanced by antimycin A (10‐7M) and blocked by iodoacetate (10‐4M). In the absence of glycolytic substrates and metabolic inhibitors no accumulation of lactate was noted whereas in the presence of antimycin A (10‐7M) a slight but statistically significant accumulation occurred.