Computerized correction of blood base excess to full hemoglobin-O2 saturation.

BACKGROUND AND OBJECTIVE: A mathematical procedure was developed to obtain an accurate coefficient (-∆BEB) for the correction of blood base excess to full hemoglobin-O2 saturation taking into account actual 2,3-diphosphoglycerate (2,3-DPG) concentration. METHODS: Previously published laboratory data were carefully processed through regression analysis, by correlating laboratory measurements of -∆BEB with the corresponding values of plasma pH, CO2 tension and 2,3-DPG. RESULTS: Data processing allowed the development of two accurate fits to the original laboratory results for blood with normal 2,3-DPG and for blood depleted of 2,3-DPG (r2 = 0.990 and 0.986, respectively, p < 0.0001 for both), as the main components of a procedure for estimating the correction factor in normal conditions and in moderate-to-extreme illness with extreme acid-base abnormalities. CONCLUSIONS: This regression-derived procedure can easily integrate any computer system to automatically obtain an accurate correction factor on the basis of plasma pH, CO2 tension, and 2,3-DPG concentration if available. It may also allow for the assessment of small stoichiometric quantities involved in O2-linked H+ exchange and equilibrium (Haldane effect) in computer programs dedicated to these types of investigations.

Erratum to "Prognostic Role of Serum Amino Acids in Head and Neck Cancer".

[This corrects the article DOI: 10.1155/2020/2291759.].

Increased ratio of P[v-a]CO2 to C[a-v]O2 without global hypoxia: the case of metformin-induced lactic acidosis.

The ratio of venoarterial CO2 tension to arteriovenous O2 content difference (P[v-a]CO2/C[a-v]O2) increases when lactic acidosis is due to inadequate oxygen supply (hypoxia); we aimed to verify whether it also increases when lactic acidosis develops because of mitochondrial dysfunction (dysoxia) with constant oxygen delivery. Twelve anaesthetised, mechanically ventilated pigs were intoxicated with IV metformin (4.0 to 6.4 g over 2.5 to 4.0 h). Saline and norepinephrine were used to preserve oxygen delivery. Lactate and P[v-a]CO2/C[a-v]O2 were measured every one or two hours (arterial and mixed venous blood). During metformin intoxication, lactate increased from 0.8 (0.6-0.9) to 8.5 (5.0-10.9) mmol/l (p < 0.001), even if oxygen delivery remained constant (from 352 ± 78 to 343 ± 97 ml/min, p = 0.098). P[v-a]CO2/C[a-v]O2 increased from 1.6 (1.2-1.8) to 2.3 (1.9-3.2) mmHg/ml/dl (p = 0.004). The intraclass correlation coefficient between lactate and P[v-a]CO2/C[a-v]O2 was 0.72 (p < 0.001). We conclude that P[v-a]CO2/C[a-v]O2 increases when lactic acidosis is due to dysoxia. Therefore, a high P[v-a]CO2/C[a-v]O2 may not discriminate hypoxia from dysoxia as the cause of lactic acidosis.

Prognostic Role of Serum Amino Acids in Head and Neck Cancer.

INTRODUCTION: Serum amino acid (AA) profiles represent a valuable tool in the metabolic assessment of cancer patients; still, information on the AA pattern in head and neck cancer (HNC) patients is insufficient. The aim of the study was to assess whether serum AA levels were associated with the stage of neoplastic disease and prognosis in primary HNC patients. METHODS: Two hundred and two primary HNC patients were included in the study. Thirty-one AAs and derivatives were measured in serum through an ultraperformance liquid chromatography-mass spectrometry (UPLC-MS). The association between AA concentrations and the stage (advanced versus early) of HNC was estimated using a multivariable logistic regression model. A multivariable Cox regression model was used to evaluate the prognostic significance of each AA. RESULTS: At the multivariable logistic regression analysis, increased levels of alpha-aminobutyric acid, aminoadipic acid, histidine, proline, and tryptophan were associated with a reduced risk of advanced stage HNC, while high levels of beta-alanine, beta-aminobutyric acid, ethanolamine, glycine, isoleucine, 4-hydroxyproline, and phenylalanine were associated with an increased risk of advanced stage HNC. Furthermore, at multivariate analysis, increased levels of alpha-aminobutyric acid were associated with increased overall survival (OS), while high levels of arginine, ethanolamine, glycine, histidine, isoleucine, 4-hydroxyproline, leucine, lysine, 3-methylhistidine, phenylalanine, and serine were associated with decreased OS. CONCLUSIONS: Our study suggests that AA levels are associated with the stage of disease and prognosis in patients with HNC. More study is necessary to evaluate if serum AA levels may be considered a hallmark of HNC and prove to be clinically useful markers of disease status and prognosis in HNC patients.

Clinical use of plasma chitotriosidase in severe sepsis.

Plasma chitotriosidase activity (ChT) was previously proposed to quantify severity of sepsis. In a complex surgical case, with prolonged sepsis and consistently high ChT, we found that the least increased values occurred in stages of extreme illness, with profound hypocholesterolemia. ChT needs better characterization before becoming a reliable biomarker of septic evolution.

High phosphoserine in sepsis: panel of clinical and plasma amino acid correlations.

The determination of plasma phosphoserine concentration in sepsis is uncommon, and the clinical and metabolic correlations of abnormally high phosphoserine are basically unknown. We analyzed 430 determinations of phosphoserine, other amino acid (AA) levels and ancillary variables obtained in 18 septic patients, in order to assess the biochemical and clinical correlations of changes in phosphoserine. Phosphoserine ranged between 5 and 55 micromol/L (n.v. < 12). Increasing phosphoserine was associated with higher severity of illness and death, and its best AA correlates were increasing cystathionine, 3-methylhistidine, histidine, hydroxyproline and tyrosine (r > 0.65, p < 0.001 for all). High phosphoserine seemed to cumulatively reflect kidney and liver dysfunction and enhanced proteolysis. As a collateral finding, 3-methylhistidine (a best correlate of phosphoserine) was also inversely related to nutritional AA dose (p < 0.001). These data suggest that in septic patients the determination of plasma phosphoserine may provide useful information on severity of septic illness and prognosis. The observed correlations also indirectly evidenced an impact of nutritional AA dose in moderating proteolysis.

Parenteral nutrition in liver resection.

Albeit a very large number of experiments have assessed the impact of various substrates on liver regeneration after partial hepatectomy, a limited number of clinical studies have evaluated artificial nutrition in liver resection patients. This is a peculiar topic because many patients do not need artificial nutrition, while several patients need it because of malnutrition and/or prolonged inability to feeding caused by complications. The optimal nutritional regimen to support liver regeneration, within other postoperative problems or complications, is not yet exactly defined. This short review addresses relevant aspects and potential developments in the issue of postoperative parenteral nutrition after liver resection.

Characterization of alpha-amino-n-butyric acid correlations in sepsis.

Little information is available on the patterns of changes and significance of plasma alpha-amino-n-butyric acid (ABA, µmol/L) in various conditions, particularly in sepsis. This study has been performed to assess the patterns of correlation among ABA, other amino acids, and other variables in a group of septic patients with various degrees of illness. More than 400 determinations of ABA, other amino acids, and simultaneously collected blood variables were obtained in 17 patients with sepsis. The distribution of ABA was characterized by the clustering of most measurements within the normal range (<41 µmol/L), with the spreading of abnormally increased values up to 151 µmol/L. Abnormal increases in ABA were related directly to alanine, serine, tyrosine, histidine, proline, threonine, glycine, glutamine, cysteine, lysine, cystathionine, leucine, valine, phenylalanine, arginine, and citrulline (r(2) from 0.86 to 0.32) and related inversely to aspartate, taurine, and phosphoethanolamine (r(2) from 0.62 to 0.50) (P < 0.001 for all). Furthermore, increased ABA was correlated with increasing total aminoacidemia, lactate, neutrophil concentration, creatinine, ammonia, osmolarity, glucose, and bilirubin and with decreasing AA Fischer ratio and peripheral O(2) extraction (r(2) from 0.87 to 0.16) (P < 0.001 for all). High ABA was also associated with low cholesterol, taurine, and platelet count, and with high 3-methylhistidine (partly anticipating the increase), high blood urea nitrogen, and pulmonary shunt (P < 0.001 for all). Finally, high ABA was related to the worsening of sepsis-related organ failure assessment score (SOFA score) and of most plasma AA clearances (P < 0.001 for all). Abnormally increased ABA may signal and partly anticipate the transition to an extreme derangement of septic metabolic patterns, characterized by the worsening of protein hypercatabolism with hyperaminoacidemia and by signs of impaired hepatic amino acid metabolism and oxidative metabolism. Increased ABA may represent an additional landmark of transition to extreme illness, compelling the need for the aggressive resolution of sepsis.

Reappraisal of surgical indications and approach for liver hemangioma: single-center experience on 74 patients.

BACKGROUND: Liver hemangiomas are rarely large, symptomatic, or presenting atypical imaging patterns. Surgery is rarely needed; indications and choice of the best technique remain not precisely defined. METHODS: Features of hemangiomas and surgical indications were assessed in 74 patients (mean follow-up 63.2 months). In 40 operated patients, the results of liver resection versus enucleation were compared. RESULTS: Most hemangiomas (60/74, 81.1%) showed no size increment. In 40 operated patients (40/74, 54.1%) the mean tumor size (11.9 cm, range 2.6-46.0) was larger than in nonoperated patients (11.9 vs 6.0 cm, P = .0002). Surgical indications were specific symptoms, tumor enlargement, Kasabach-Merritt syndrome, and uncertain diagnosis. Mortality (nil), morbidity (10.0%), and transfusion rate (15.0%) were similar for 28 liver resections versus 12 enucleations; bleeding was more related to large hemangioma size than to the choice of either technique. Liver ischemia techniques, autotransfusion, and intraoperative blood salvage reduced the risk of transfusion. CONCLUSIONS: Surgery is rarely indicated, has a low risk, and has similar results for liver resection versus enucleation. Risk of bleeding is related more to the large size of the hemangioma than to the type of surgery (resection or enucleation). In these patients, management, the need for surgery, and the choice of technique should be carefully individualized.

Intrahepatic cholangiocarcinoma: prognostic factors after liver resection.

Liver resection may represent the only hope of cure for patients with intrahepatic cholangiocarcinoma (IHC) but long-term results are still far from satisfactory and the impact of prognostic factors is still controversial. Fifty-five patients underwent hepatectomy for IHC between 1997 and 2008 in our unit. Features of the patients and the tumors, operations, postoperative and long-term results were retrospectively assessed. Twenty-one patients had HBV/HCV infection, four had congenital biliary dilatation. Thirty-two patients had increased CA 19-9; 12 had multiple (≥ 4) tumors. Operations included 43 major resections, with 9 resections of biliary confluence, 40 regional lymphadenectomies. Operative mortality and morbidity were 0 and 27.3%, respectively. There were 44 R0-resections (80.0%). Lymphadenectomy yielded lymph node metastases in 14 cases (14/40; 35.0%). Five-year overall and disease-free survival rates were 30.2 and 27.5%, respectively. At multivariate analysis the strongest poor prognostic factor for overall survival was tumor stage. This factor, with multiplicity of lesions (≥ 4) and tumor grading > 2, was significant predictor of recurrence. CA19-9 > 100 IU/mL and tumor grading > 2 were found to be significantly related with early multinodular hepatic recurrence. Patients with lymph node metastases had significantly lower overall and disease-free survival but patients who underwent lymph node dissection with negative lymph nodes at final pathology showed significantly higher 5-year disease-free survival than patients who did not underwent lymphadenectomy. In conclusion, these results support the role of hepatectomy with regional lymphadenectomy as the best available treatment for IHC. Prognosis after liver resection correlates with clinical stage and multiplicity of lesions.

Significance of hemoglobin concentration in determining blood CO2 binding capacity in critical illness.

This study was performed to provide simplified quantitative evidence of the impact of hemoglobin concentration on blood CO(2) binding and transport capacity. Linear regression equations were obtained for gas analyses data obtained from 85 surgical patients with sepsis and various degrees of illness. Venoarterial CO(2) concentration differences were calculated by a complex procedure, and then simplified equations were derived to highlight the impact of hemoglobin concentration on blood CO(2) binding and the Haldane effect. The results showed that, although in normal conditions the impact of hemoglobin concentration is less evident, it becomes relevant in extreme conditions, also protecting against venous and tissue hypercapnia and acidosis.