Discordance between measured and calculated total carbon dioxide

Abstract Recent studies on the agreement and correlation between measured and calculated total CO2 (TCO2) have yielded conflicting results. Pre-analytical variation could have been partially responsible. While keeping such variables at an absolute minimum, we found excellent correlation (r = 0.98) in 88 samples, with only a small variation in agreement between measured and calculated TCO2 values (SD = 1.1 mmol/L), which could be a function of variation in apparent pK (pK'). A subsequent evaluation of 913 consecutive samples, routinely analyzed, yielded similar results. These results suggest that some of the discrepancies reported in the literature could be ascribable to differences in sample types and sample handling. Rigid control of pre-analytical procedures is therefore a prerequisite in studies on this topic. The two methods were found to agree over a wide range of values, such that either of them could be used to evaluate clinical acid-base status accurately.

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Evaluation of the Prognostic Value of Lactate and Acid-base Status in Patients Presenting to the Emergency Department

10.21203/rs.3.rs-92196/v1 ◽

2020 ◽

Author(s):

Ramiro D'Abrantes ◽

Laura DUNN ◽

Tim MCMILLAN ◽

Ben CORNWELL ◽

Ben BLOOM ◽

...

Keyword(s):

Emergency Department ◽

Hospital Mortality ◽

Predictive Value ◽

Point Of Care ◽

Acid Base ◽

Wide Range ◽

Acid Base Status ◽

Emergency Department Patients ◽

Lactate Levels ◽

High Lactate

Abstract IntroductionPoint-of-care metabolic screens are frequently used in the assessment of critical illness. Lactate levels predict mortality in a wide range of patients presenting to the Emergency Department but the effect of co-existing acidosis is unknown. We investigated the effect that acidosis has on in-hospital mortality for patients with hyperlactataemia. Methods This is a retrospective cohort study. The inclusion criteria were patients over 17 years of age who received a metabolic panel on arrival to the resuscitation area of the Emergency Department. The primary outcome was in-hospital mortality. The groups were normal lactate (0.0-2.0 mmol/L), intermediate lactate (2.1-4.0 mmol/L) and high lactate (>4.0 mmol/L), with and without acidosis. Odds ratios (OR) were calculated to assess the differences in mortality rates between groups stratified by lactate and acid-base status.Results 4107 metabolic panels were collected and 3238 were assessed. 510 (15.8%) & 784 (24.2%) patients had a normal lactate and acidosis or no acidosis respectively. 587 (18.1%) & 842 (26.0%) patients had intermediate lactate and acidosis or no acidosis respectively. 388 (12.0%) & 127 (3.9%) patients had high lactate and acidosis or no acidosis respectively. The overall mortality was 5%. In normal lactate group mortality was 4.3% and 0.6%, intermediate lactate mortality was 5.6% and 2.6%, and high lactate group mortality was 19.3% and 3.9%, with and without acidosis respectively. Combining base excess < -6 and lactate >4 mmol/L had a sensitivity of 39%, specificity of 96%, positive predictive value of 32% and a negative predictive value of 98% for in-hospital mortality, OR 14.0 (95% CI 9.77 – 20.11). Conclusion In an undifferentiated cohort of Emergency Department patients presenting to the resuscitation area lactaemia associated with acidosis is a more accurate predictor of in-hospital mortality than hyperlactataemia.

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Is urea formation regulated primarily by acid-base balance in vivo?

AJP Renal Physiology ◽

10.1152/ajprenal.1986.250.4.f605 ◽

1986 ◽

Vol 250 (4) ◽

pp. F605-F612 ◽

Cited By ~ 2

Author(s):

M. L. Halperin ◽

C. B. Chen ◽

S. Cheema-Dhadli ◽

M. L. West ◽

R. L. Jungas

Keyword(s):

Dietary Protein ◽

Urea Synthesis ◽

Acid Base Balance ◽

Severe Metabolic Acidosis ◽

Acid Base ◽

Wide Range ◽

Base Balance ◽

Acid Load ◽

Acid Base Status

Large quantities of ammonium and bicarbonate are produced each day from the metabolism of dietary protein. It has recently been proposed that urea synthesis is regulated by the need to remove this large load of bicarbonate. The purpose of these experiments was to test whether the primary function of ureagenesis in vivo is to remove ammonium or bicarbonate. The first series of rats were given a constant acid load as hydrochloric acid or ammonium chloride; individual rats received a constant nitrogen load at a time when their plasma acid-base status ranged from normal (pH 7.4, 28 mM HCO3) to severe metabolic acidosis (pH 6.9, 6 mM HCO3). Urea plus ammonium excretions and the blood urea, glutamine, and ammonium concentrations were monitored with time. Within the constraints of non-steady-state conditions, the rate of urea synthesis was constant and the plasma glutamine and ammonium concentrations also remained constant; thus it appears that the rate of urea synthesis was not primarily regulated by the acid-base status of the animal in vivo over a wide range of plasma ammonium concentrations. In quantitative terms, the vast bulk of the ammonium load was converted to urea over 80 min; only a small quantity of ammonium appeared as circulating glutamine or urinary ammonium. Urea synthesis was proportional to the nitrogen load. A second series of rats received sodium bicarbonate; urea synthesis was not augmented by a bicarbonate load. We conclude from these studies that the need to dispose of excess bicarbonate does not primarily determine the rate of ureagenesis in vivo. The data support the classical view that ureagenesis is controlled by the quantity of ammonium to be removed.

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Total Carbon Dioxide Versus pH for Determining Acid-Base Status in Patients on Continuous Kidney Replacement Therapy: A Cohort Study

American Journal of Kidney Diseases ◽

10.1053/j.ajkd.2020.06.015 ◽

2020 ◽

Author(s):

Tyler B. Woodell ◽

Luke Webster ◽

Ravindra Mehta ◽

Etienne Macedo ◽

Dena E. Rifkin

Keyword(s):

Carbon Dioxide ◽

Cohort Study ◽

Replacement Therapy ◽

Total Carbon ◽

Acid Base ◽

Kidney Replacement Therapy ◽

Acid Base Status

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To Manage Infantile Hypertrophic Pyloric Stenosis by "Double-Y Pyloromyotomy" is a better Surgical Approach

Journal of Paediatric Surgeons of Bangladesh ◽

10.3329/jpsb.v1i2.19532 ◽

2014 ◽

Vol 1 (2) ◽

pp. 143-147

Author(s):

Md. Ansar Ali ◽

Kaniz Hasina ◽

Shahnoor Islam ◽

Md. Ashraf Ul Huq ◽

Md. Mahbub-Ul Alam ◽

...

Keyword(s):

Weight Gain ◽

Pyloric Stenosis ◽

Hypertrophic Pyloric Stenosis ◽

Treatment Modalities ◽

Infantile Hypertrophic Pyloric Stenosis ◽

Postoperative Vomiting ◽

Acid Base ◽

Feeding Regimes ◽

Acid Base Status ◽

Postoperative Feeding

Background: Different treatment modalities and procedures have been tried for the management of infantile hypertrophic pyloric stenosis. But surgery remains the mainstay for management of IHPS. Ramstedts pyloromyotomy was described almost over a hundred years ago and to date remains the surgical technique of choice. An alternative and better technique is the double-Y pyloromyotomy, which offer better results for management of this common condition.Methods: A prospective comparative interventional study of 40 patients with IHPS was carried out over a period of 2 years from July 2008 to July 2010. The patients were divided into 2 equal groups of 20 patients in each. The study was designed that all patients selected for study were optimized preoperatively regarding to hydration, acid-base status and electrolytes imbalance. All surgeries were performed after obtaining informed consent. Standard preoperative preparation and postoperative feeding regimes were used. The patients were operated on an alternate basis, i.e., one patient by Double-Y Pyloromyotomy(DY) and the next by aRamstedts Pyloromyotomy (RP). Data on patient demographics, operative time, anesthesia complications, postoperative complications including vomiting and weight gain were collected. Patients were followed up for a period of 3 months postoperatively. Statistical assessments were done by using t test.Results: From July 2008 through July 2010, fourty patients were finally analyzed for this study. Any statistical differences were observed in patient population regarding age, sex, weight at presentation, symptoms and clinical condition including electrolytes imbalance and acid-base status were recorded. Significant differences were found in postoperative vomiting and weight gain. Data of post operative vomiting and weight gain in both groups were collected. Vomiting in double-Y(DY) pyloromyotomy group (1.21 ± 0.45days) vs Ramstedts pyloromyotomy (RP) group(3.03 ± 0.37days) p= 0.0001.Weight gain after 1st 10 days DY vs RP is ( 298 ± 57.94 gm vs193±19.8 gm p=0.0014), after 1 month (676.67±149.84 gm vs 466.67 ± 127.71 gm, p=0.0001), after 2months (741.33± 278.74 gm vs 490±80.62 gm, p=0.002) and after 3 months (582±36.01gm vs 453.33±51.64 gm, p=0.0001).No long-term complications were reported and no re-do yloromyotomy was needed.Conclusion: The double-Y pyloromyotomy seems to be a better technique for the surgical management of IHPS. It may offer a better functional outcome in term of postoperative vomiting and weight gain.DOI: http://dx.doi.org/10.3329/jpsb.v1i2.19532

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