Acid-base Metabolism Research Articles

Risk factors for renal progression in patients with CKD and coexisting COPD.

Chronic diseases rarely occur in isolation, and chronic kidney disease (CKD) is no exception. There has been considerable research on the interplay between the heart and kidneys, but studies on the relationship between the lungs and kidneys are less common. The interaction between pulmonary and renal functions in areas such as acid-base metabolism, chronic inflammation, and bone metabolism is increasingly gaining clinical attention. In this cohort study, we examined 480 patients with stages 3-4 CKD and COPD (GOLD stages 1 and 2) to identify risk factors that contribute to the progression of renal function to a composite endpoint, which includes a 40% decline in estimated glomerular filtration rate (eGFR) and the onset of end-stage renal disease during follow-up periods. A Cox proportional hazards regression model was used to investigate the risk factors associated with the timing of renal event endpoints in the study population. Additionally, the restricted cubic spline method was used to explore the relationship between quantitative variables and survival risk. Our study included 480 eligible patients with an average follow-up period of 21.41 ± 14.90months, during which 224 individuals (46.7%) experienced the composite renal endpoints. Multivariable Cox regression analysis revealed that systolic blood pressure (SBP) [1.01 (1.00-1.02), p = 0.002], hemoglobin (Hb) [HR 0.89 (0.83-0.96), p = 0.002], albumin (Alb) [0.96 (0.93-0.99), p = 0.009], and edema [1.73 (1.29-2.33), p < 0.001] were independent risk factors for the renal endpoints. The adjusted multivariable Cox regression analysis demonstrated that elevated SBP and edema were factors that promoted the occurrence of composite endpoints, while higher levels of Hb and Alb were protective factors.

The impact of alternate-day fasting on the salivary gland stem cell compartments in non-obese diabetic mice with newly established Sjögren's syndrome.

Intermittent fasting exerts a profound beneficial influence on a spectrum of diseases through various mechanisms including regulation of immune responses, elimination of senescent- and pathogenic cells and improvement of stem cell-based tissue regeneration in a disease- and tissue-dependent manner. Our previous study demonstrated that alternate-day fasting (ADF) led to alleviation of xerostomia and sialadenitis in non-obese diabetic (NOD) mice, a well-defined model of Sjögren's syndrome (SS). This present study delved into the previously unexplored impacts of ADF in this disease setting and revealed that ADF increases the proportion of salivary gland stem cells (SGSCs), defined as the EpCAMhi cell population among the lineage marker negative submandibular gland (SMG) cells. Furthermore, ADF downregulated the expression of p16INK4a, a cellular senescence marker, which was concomitant with increased apoptosis and decreased expression and activity of NLRP3 inflammasomes in the SMGs, particularly in the SGSC-residing ductal compartments. RNA-sequencing analysis of purified SGSCs from NOD mice revealed that the significantly downregulated genes by ADF were mainly associated with sugar metabolism, amino acid biosynthetic process and MAPK signaling pathway, whereas the significantly upregulated genes related to fatty acid metabolic processes, among others. Collectively, these findings indicate that ADF increases the SGSC proportion, accompanied by a modulation of the SGSC property and a switch from sugar- to fatty acid-based metabolism. These findings lay the foundation for further investigation into the functionality of SGSCs influenced by ADF and shed light on the cellular and molecular mechanisms by which ADF exerts beneficial actions on salivary gland restoration in SS.

SERIAL CHANGES IN METABOLIC ACID-BASE STATUS IN THREE SPECIES OF ANESTHETIZED CAPTIVE LARGE FELID.

Determination of acid-base status contributes important information about patient health, including for patients under anesthesia. There is a paucity of information about the determinants of acid-base status of large felids managed under anesthesia, and advancement of such knowledge may contribute to patient safety. This study serially monitored the individual metabolic acid-base status of 11 large felids, including lions (Panthera leo), tigers (Panthera tigris), and cheetahs (Acinonyx jubatus), under general anesthesia. We analyzed the contributions of measured strong ions (sodium, chloride, potassium, lactate), weak acids and buffers (albumin, phosphate and bicarbonate), and unmeasured anions to standardized extracellular base excess (SBE). A general linear model assessed for species differences in these parameters, with time since immobilization, SBE, and mean arterial pressure as covariates. By employing a Stewart-based analytical approach, it was possible to separate chloremic and unmeasured anion contributions to metabolic acid base status. This provided a basis for identifying mixed metabolic processes, generating differentials for underlying causes. Using normal acid base parameters for domestic felids, metabolic acidosis was found to be prevalent. Frequent evidence of unmeasured anion accumulation was also found, with unmeasured anions occasionally exceeding 5mmol/L. These findings warrant further inquiry into the drivers and clinical significance of metabolic acidosis and unmeasured anion accumulations in anesthetized large felids, encouraging further anion identity studies to elucidate possible causes. Reference ranges need to be established for acid-base parameters in large felids as a foundation for interpreting more controlled, prospective research into determinants of metabolic acid-base status in these animals under anesthesia.

Interpretation of acid-base metabolism on arterial blood gas samples via machine learning algorithms.

Arterial blood gas evaluation is crucial for critically ill patients, as it provides essential information about acid-base metabolism and respiratory balance, but evaluation can be complex and time-consuming. Artificial intelligence can perform tasks that require human intelligence, and it is revolutionizing healthcare through technological advancements. This study aims to assess arterial blood gas evaluation using artificial intelligence algorithms. The study included 21.541 retrospective arterial blood gas samples, categorized into 15 different classes by experts for evaluating acid-base metabolism status. Six machine learning algorithms were utilized; accuracy, balanced accuracy, sensitivity, specificity, precision, and F1 values of the models were determined; and ROC curves were drawn to assess areas under the curve for each class. Evaluation of which sample was estimated in which class was conducted using the confusion matrices of the models. The bagging classifier (BC) model achieved the highest balanced accuracy with 99.24%, whereas the XGBoost model reached the highest accuracy with 99.66%. The BC model shows 100% sensitivity for nine classes and 100% specificity for 10 classes, and the model correctly predicted 6438 of 6463 test samples and achieved an accuracy of 99.61%, with an area under the curve > 0.9 in all classes on a class basis. The machine learning models developed exhibited remarkable accuracy, sensitivity, and specificity in predicting the status of acid-base metabolism. However, implementing these models can aid clinicians, freeing up their time for more intricate tasks.

Urinary acid-base excretion deciphers high acid load from colonic bicarbonate loss in intestinal failure patients with ileocolonic anastomosis – Guidance for composition of parenteral support

Background & AimsAcid-base disturbances are common in short bowel (SB) patients due to increased intestinal bicarbonate loss. However, the resulting systemic acid load has not been quantified. Base excess is used to monitor metabolic acid-base disturbances but inadequately reflects the acid load. Our aim was to investigate the systemic acid/base load in SB-patients to obtain quantitative estimates to guide the composition of parenteral support. MethodsWe calculated total acid load in SB patients by summing 24-hour urinary net acid excretion (NAE) and the provision of base equivalents in parenteral support. We then compared differences among anatomical SB-types: jejunostomy (SB-J), jejunocolostomy (SB-JC), and jejunoileostomy (SB-JIC). 47 urine samples from 34 SB patients were analyzed for bicarbonate (HCO3-), ammonium (NH4+), and titratable acidity (TA) concentrations. NAE was calculated as (TA + NH4+) - HCO3-. Mixed-effects repeated-measures models were used to statistically examine differences between SB-types and associations with parenteral nutrition and NAE. A healthy cohort served as control. ResultsIn comparison to SB-J, SB-JC patients had a 4.1 mmol/l lower base excess (95% CI: -6.3 to -1.8) and an 84.5 mmol/day higher total acid load (CI: 41.3 to 127.7). There were no significant differences between SB-JIC and SB-J regarding base excess, NAE, or total acid load. Higher amounts of infused acetate, sodium, and chloride, but not the acetate/chloride ratio, were associated with lower NAE and higher base excess. ConclusionsDue to increased colonic bicarbonate loss, patients with SB-JC have a ∼4.4-fold higher acid load than healthy controls. The ion transport mechanisms mediating this bicarbonate loss from the remaining colon need further experimental investigation. NAE could be a useful tool to adjust base infusion in SB.

Combined pH ratiometry and fluorescence lectin-binding analysis (pH-FLBA) for microscopy-based analyses of biofilm pH and matrix carbohydrates.

Bacterial biofilms have a complex and heterogeneous three-dimensional architecture that is characterized by chemically and structurally distinct microenvironments. Confocal microscopy-based pH ratiometry and fluorescence lectin-binding analysis (FLBA) are well-established methods to characterize pH developments and the carbohydrate matrix architecture of biofilms at the microscale. Here, we developed a combined analysis, pH-FLBA, to concomitantly map biofilm pH and the distribution of matrix carbohydrates in bacterial biofilms while preserving the biofilm microarchitecture. As a proof of principle, the relationship between pH and the presence of galactose- and fucose-containing matrix components was investigated in dental biofilms grown with and without sucrose. The pH response to a sucrose challenge was monitored in different areas at the biofilm base using the ratiometric pH-sensitive dye C-SNARF-4. Thereafter, the fucose- and galactose-specific fluorescently labeled lectins Aleuria aurantia lectin (AAL) and Morus nigra agglutinin G (MNA-G) were used to visualize carbohydrate matrix components in the same biofilm areas and their immediate surroundings. Sucrose during growth significantly decreased biofilm pH (P < 0.05) and increased the amounts of both MNA-G- and AAL-targeted matrix carbohydrates (P < 0.05). Moreover, it modulated the biofilm composition towards a less diverse community dominated by streptococci, as determined by 16S rRNA gene sequencing. Altogether, these results suggest that the production of galactose- and fucose-containing matrix carbohydrates is related to streptococcal metabolism and, thereby, pH profiles in dental biofilms. In conclusion, pH-FLBA using lectins with different carbohydrate specificities is a useful method to investigate the association between biofilm pH and the complex carbohydrate architecture of bacterial biofilms.IMPORTANCEBiofilm pH is a key regulating factor in several biological and biochemical processes in environmental, industrial, and medical biofilms. At the microscale, microbial biofilms are characterized by steep pH gradients and an extracellular matrix rich in carbohydrate components with diffusion-modifying properties that contribute to bacterial acid-base metabolism. Here, we propose a combined analysis of pH ratiometry and fluorescence lectin-binding analysis, pH-FLBA, to concomitantly investigate the matrix architecture and pH developments in microbial biofilms, using complex saliva-derived biofilms as an example. Spatiotemporal changes in biofilm pH are monitored non-invasively over time by pH ratiometry, while FLBA with lectins of different carbohydrate specificities allows mapping the distribution of multiple relevant matrix components in the same biofilm areas. As the biofilm structure is preserved, pH-FLBA can be used to investigate the in situ relationship between the biofilm matrix architecture and biofilm pH in complex multispecies biofilms.

Evaluation of the Acid-Base Status in Patients Admitted to the ICU Due to Severe COVID-19: Physicochemical versus Traditional Approaches.

Stewart's approach is known to have better diagnostic accuracy for the identification of metabolic acid-base disturbances compared to traditional methods based either on plasma bicarbonate concentration ([HCO3-]) and anion gap (AG) or on base excess/deficit (BE). This study aimed to identify metabolic acid-base disorders using either Stewart's or traditional approaches in critically ill COVID-19 patients admitted to the ICU, to recognize potential hidden acid-base metabolic abnormalities and to assess the prognostic value of these abnormalities for patient outcome. This was a single-center retrospective study, in which we collected data from patients with severe COVID-19 admitted to the ICU. Electronical files were used to retrieve data for arterial blood gases, serum electrolytes, and proteins and to derive [HCO3-], BE, anion gap (AG), AG adjusted for albumin (AGadj), strong ion difference, strong ion gap (SIG), and SIG corrected for water excess/deficit (SIGcorr). The acid-base status was evaluated in each patient using the BE, [HCO3-], and physicochemical approaches. We included 185 patients. The physicochemical approach detected more individuals with metabolic acid-base abnormalities than the BE and [HCO3-] approaches (p < 0.001), and at least one acid-base disorder was recognized in most patients. According to the physicochemical method, 170/185 patients (91.4%) had at least one disorder, as opposed to the number of patients identified using the BE 90/186 (48%) and HCO3 62/186 (33%) methods. Regarding the derived acid-base status variables, non-survivors had greater AGadj, (p = 0.013) and SIGcorr (p = 0.035) compared to survivors. The identification of hidden acid-base disturbances may provide a detailed understanding of the underlying conditions in patients and of the possible pathophysiological mechanisms implicated. The association of these acid-base abnormalities with mortality provides the opportunity to recognize patients at increased risk of death and support them accordingly.

The physiological consequences of a very large natural meal in a voracious marine fish, the staghorn sculpin (Leptocottus armatus).

Little information exists on physiological consequences when wild fish eat natural food. Staghorn sculpins at 10-13°C voluntarily consumed 15.8% of their body mass in anchovies. Gastric clearance was slow with >60% of the meal retained in the stomach at 48 h, and was not complete until 84 h. At 14-24 h post-feeding, pH was depressed by 3 units and Cl- concentration was elevated 2-fold in gastric chyme, reflecting HCl secretion, while in all sections of the intestine, pH declined by 1 pH unit but Cl- concentration remained unchanged. PCO2and total ammonia concentration were greatly elevated throughout the tract, whereas PNH3and HCO3- concentration were depressed. Intestinal HCO3- secretion rates, measured in gut sacs in vitro, were also lower in fed fish. Whole-animal O2 consumption rate was elevated approximately 2-fold for 72 h post-feeding, reflecting 'specific dynamic action', whereas ammonia and urea-N excretion rates were elevated about 5-fold. Arterial blood exhibited a modest 'alkaline tide' for about 48 h, but there was negligible excretion of metabolic base to the external seawater. PaCO2and PaO2remained unchanged. Plasma total amino acid concentration and total lipid concentration were elevated about 1.5-fold for at least 48 h, whereas small increases in plasma total ammonia concentration, PNH3and urea-N concentration were quickly attenuated. Plasma glucose concentration remained unchanged. We conclude that despite the very large meal, slow processing with high efficiency minimizes internal physiological disturbances. This differs greatly from the picture provided by previous studies on aquacultured species using synthetic diets and/or force-feeding. Questions remain about the role of the gastro-intestinal microbiome in nitrogen and acid-base metabolism.

Combined western diet and bisphenol A exposure induces an oxidative stress-based paraoxonase 1 response in larval zebrafish

Paraoxonase 1 (PON1) is an antioxidant enzyme linked to metabolic disorders by genome-wide association studies in humans. Exposure to metabolic disrupting chemicals (MDCs) such as bisphenol A (BPA), together with genetic and dietary factors, can increase the risk of metabolic disorders. The objective of this study was to investigate how PON1 responds to the metabolic changes and oxidative stress caused by a western diet, and whether exposure to BPA alters the metabolic and PON1 responses. Zebrafish larvae at 14 days post fertilization were fed a custom-made western diet with and without aquatic exposure to two concentrations of BPA for 5 days. A combination of western diet and 150 μg/L BPA exposure resulted in a stepwise increase in weight, length and oxidative stress, suggesting that BPA amplifies the western diet-induced metabolic shift. PON1 arylesterase activity was increased in all western diet and BPA exposure groups and PON1 lactonase activity was increased when western diet was combined with exposure to 1800 μg/L BPA. Both PON1 activities were positively correlated to oxidative stress. Based on our observations we hypothesize that a western diet caused a shift towards fatty acid-based metabolism, which was increased by BPA exposure. This shift resulted in increased oxidative stress, which in turn was associated with a PON1 activity increase as an antioxidant response. This is the first exploration of PON1 responses to metabolic challenges in zebrafish, and the first study of PON1 in the context of MDC exposure in vertebrates.

Effect of Pre-Hospital Intravenous Fluids on Initial Metabolic Acid-Base Status in Trauma Patients: A Retrospective Cohort Study.

Despite its known harmful effects, normal saline is still commonly used in the treatment of hypovolemia in polytrauma patients. Given the lack of pre-hospital research on this topic, the current study aims to assess the current practice of fluid administration during the pre-hospital phase of care and its effects on initial metabolic acid-base status in trauma patients. We extracted and completed data from patients recorded in the Lausanne University Hospital (CHUV) trauma registry between 2008 and 2019. Patients were selected according to their age, the availability of a blood gas analysis after arrival at the emergency room, data availability in the trauma registry, and the modality of arrival in the ED. The dominantly administered pre-hospital fluid was normal saline. No association between the type of fluid administered during the pre-hospital phase and the presence of hyperchloremic acidosis in the ED was observed.

ECSIT Is a Critical Factor for Controlling Intestinal Homeostasis and Tumorigenesis through Regulating the Translation of YAP Protein.

The intestinal epithelium is the fastest renewing tissue in mammals and its regenerative process must be tightly controlled to minimize the risk of dysfunction and tumorigenesis. The orderly expression and activation of Yes-associated protein (YAP) are the key steps in driving intestinal regeneration and crucial for intestinal homeostasis. However, the regulatory mechanisms controlling this process remain largely unknown. Here, it is discovered that evolutionarily conserved signaling intermediate in Toll pathways (ECSIT), a multi-functional protein, is enriched along the crypt-villus axis. Intestinal cell-specific ablation of ECSIT results in the dysregulation of intestinal differentiation unexpectedly accompanied with enhanced YAP protein dependent on translation, thus transforming intestinal cells to early proliferative stem "-like" cells and augmenting intestinal tumorigenesis. Loss of ECSIT leads to metabolic reprogramming in favor of amino acid-based metabolism, which results in demethylation of genes encoding the eukaryotic initiation factor 4F pathway and their increased expression that further promotes YAP translation initiation culminating in intestinal homeostasis imbalance and tumorigenesis. It is also shown that the expression of ECSIT is positively correlated with the survival of patients with colorectal cancer. Together, these results demonstrate the important role of ECSIT in regulating YAP protein translation to control intestinal homeostasis and tumorigenesis.

Management of regional citrate anticoagulation for continuous renal replacement therapy: guideline recommendations from Chinese emergency medical doctor consensus

Continuous renal replacement therapy (CRRT) is widely used for treating critically-ill patients in the emergency department in China. Anticoagulant therapy is needed to prevent clotting in the extracorporeal circulation during CRRT. Regional citrate anticoagulation (RCA) has been shown to potentially be safer and more effective and is now recommended as the preferred anticoagulant method for CRRT. However, there is still a lack of unified standards for RCA management in the world, and there are many problems in using this method in clinical practice. The Emergency Medical Doctor Branch of the Chinese Medical Doctor Association (CMDA) organized a panel of domestic emergency medicine experts and international experts of CRRT to discuss RCA-related issues, including the advantages and disadvantages of RCA in CRRT anticoagulation, the principle of RCA, parameter settings for RCA, monitoring of RCA (mainly metabolic acid–base disorders), and special issues during RCA. Based on the latest available research evidence as well as the paneled experts’ clinical experience, considering the generalizability, suitability, and potential resource utilization, while also balancing clinical advantages and disadvantages, a total of 16 guideline recommendations were formed from the experts’ consensus.

Sex differences in risk factors for end-stage kidney disease and death in type 2 diabetes: A retrospective cohort study.

This study investigated the sex differences in the risk of end-stage kidney disease (ESKD) and mortality, as well as the effect modification of sex on associated factors in patients with type 2 diabetes. This multicenter observational cohort study included 4328 patients with type 2 diabetes. Hazard ratios (HRs) with 95% confidence intervals (CIs) of sex for ESKD and death were estimated using Cox proportional regression with adjustment for baseline covariates. For assessing risk modification, HRs and incidence rates for ESKD and death were compared between sexes across patient characteristics using Cox proportional and Poisson regression models. During a median follow-up of 7 years, 276 patients (70% men) developed ESKD, and 241 patients (68% men) died. Men had higher risks of ESKD (HR 1.34; 95% CI 1.02-1.75; p=.034) and death (HR 1.64; 95% CI 1.24-2.16; p=.001) versus women after adjusting for multiple covariates. Among patients with microalbuminuria, men had a substantially higher risk of ESKD versus women, compared to those with normo- and macroalbuminuria (p for interaction .04). Incidence rates were also increased in men versus women with albuminuria of around 300 mg/g. No differences were detected in the association of sex and death across baseline patient subgroups. In type 2 diabetes, men had an increased risk of ESKD and death versus women. Moderately increased albuminuria was strongly associated with sex difference in developing ESKD.

Fitness of calves born from in vitro-produced fresh and cryopreserved embryos.

In cattle, vitrified/warmed (V/W) and frozen/thawed (F/T), in vitro-produced (IVP) embryos, differ in their physiology and survival from fresh embryos. In this study, we analyzed the effects of embryo cryopreservation techniques on the offspring. IVP embryos cultured with albumin and with or without 0.1% serum until Day 6, and thereafter in single culture without protein, were transferred to recipients on Day 7 as F/T, V/W, or fresh, resulting in N = 24, 14, and 13 calves, respectively. Calves were clinically examined at birth, and blood was analyzed before and after colostrum intake (Day 0), and subsequently on Day 15 and Day 30. On Day 0, calves from V/W and F/T embryos showed increased creatinine and capillary refill time (CRT) and reduced heartbeats. Calves from F/T embryos showed lower PCO2, hemoglobin, and packed cell volume than calves from V/W embryos while V/W embryos led to calves with increased Na+ levels. Colostrum effects did not differ between calves from fresh and cryopreserved embryos, indicating similar adaptive ability among calves. However, PCO2 did not decrease in calves from V/W embryos after colostrum intake. Serum in culture led to calves with affected (P < 0.05) temperature, CRT, HCO , base excess (BE), TCO2, creatinine, urea, and anion gap. On Day 15, the effects of embryo cryopreservation disappeared among calves. In contrast, Day 30 values were influenced by diarrhea appearance, mainly in calves from V/W embryos (i.e., lower values of TCO2, HCO , and BE; and increased glucose, anion gap, and lactate), although with no more clinical compromise than calves from fresh and F/T embryos. Diarrhea affected PCO2 and Na+ in all groups. Embryo cryopreservation, and/or culture, yield metabolically different calves, including effects on protein and acid-base metabolism.

Non-carbonic buffer power of whole blood is increased in experimental metabolic acidosis: An in-vitro study.

Non-carbonic buffer power (βNC) of blood is a pivotal concept in acid-base physiology as it is employed in several acid-base evaluation techniques, including the Davenport nomogram and the Van Slyke equation used for Base excess estimation in blood. So far, βNC has been assumed to be independent of metabolic acid-base status of blood, despite theoretical rationale for the contrary. In the current study, we used CO2 tonometry to assess βNC in blood samples from 10 healthy volunteers, simultaneously analyzing the electrolyte shifts across the red blood cell membrane as these shifts translate the action of intracellular non-carbonic buffers to plasma. The βNC of the blood was re-evaluated after experimental induction of metabolic acidosis obtained by adding a moderate or high amount of either hydrochloric or lactic acid to the samples. Moreover, the impact of βNC and pCO2 on the Base excess of blood was examined. In the control samples, βNC was 28.0 ± 2.5mmol/L. In contrast to the traditional assumptions, our data showed that βNC rose by 0.36mmol/L for each 1 mEq/l reduction in plasma strong ion difference (p < 0.0001) and was independent of the acid used. This could serve as a protective mechanism that increases the resilience of blood to the combination of metabolic and respiratory acidosis. Sodium and chloride were the only electrolytes whose plasma concentration changed relevantly during CO2 titration. Although no significant difference was found between the electrolyte shifts in the two types of acidosis, we observed a slightly higher rate of chloride change in hyperchloremic acidosis, while the variation of sodium was more pronounced in lactic acidosis. Lastly, we found that the rise of βNC in metabolic acidosis did not induce a clinically relevant bias in the calculation of Base excess of blood and confirmed that the Base excess of blood was little affected by a wide range of pCO2.

Utility of Stewart's Approach to Diagnose Missed Complex Acid-Base Disorders as Compared to Bicarbonate-anion Gap-based Methodology in Critically Ill Patients: An Observational Study.

BackgroundTraditional arterial blood gas (ABG) analysis may miss out on some metabolic acid–base disorders. We prospectively compared Stewart's approach in critically ill patients to traditional bicarbonate-anion gap-based methods (with and without correction for albumin) to diagnose acid–base disorders.Patients and methodsFive hundred ABG samples from medical or surgical patients in the ICU were analyzed with traditional bicarbonate-anion gap-based methodology with and without correction for albumin and Stewart's biochemical approach. The primary outcome identification of additional metabolic disorders diagnosed with Stewart's approach in comparison to bicarbonate system-based approaches. We also looked at the correlation between the strong ion gap (SIG) and the albumin-corrected anion gap (acAnion Gap).ResultsStewart's approach detected missed metabolic disorders in 58 (11.6%) blood gas results reported as “within normal limits” with the bicarbonate-uncorrected anion gap approach. In 50 (10%) of these ABGs, the acAnion Gap approach was able to diagnose the missed metabolic disorders. Thus, the albumin-corrected anion gap method had a similar diagnostic performance to Stewart's approach, as it missed additional disorders in only eight (1.6%) blood gases.ConclusionIn this study, we found that the acAnion Gap approach was similar in diagnostic performance to Stewart's approach. We feel that the corrected anion gap approach can be safely used if a ready calculator for Stewart's approach is not available.How to cite this articlePaliwal R, Pakavakis A, Divatia JV, Kulkarni AP. Utility of Stewart's Approach to Diagnose Missed Complex Acid–Base Disorders as Compared to Bicarbonate-anion Gap-based Methodology in Critically Ill Patients: An Observational Study. Indian J Crit Care Med 2022;26(1):23–32.

Blood metabolic profile and acid base status of lactating Travnik ewes in an extensive production system

The research aimed to determine the blood metabolic profile and acid-base status of lactating Travnik ewes in an extensive production system. The research was carried out on 108 lactating Travnik ewes, with an average age of 3-4 years, in their 3rd lactation. The ewes were kept on pasture, and had water and animal salt ad libitum. Hematological indicators were determined in whole blood, biochemical parameters in serum, and acid-base status was determined in plasma. The determined average values of hematological parameters were mostly within reference values, except the lower MCHC content and higher MCV content, which indicates the instability of erythrocyte constants. Average mineral concentrations were within the reference values, except for Ca and Fe concentrations which were lower and were influenced by higher milk excretion. Most of the biochemical indicators, enzyme activity, and indicators of the acid-base balance of lactating Travnik ewes’ blood were within the reference values. A high concentration of urea above the reference values was found, and concentrations of total proteins, albumins, total cholesterol, HDL and LDL cholesterol, and triglycerides at the upper limit or above the reference values were determined. Slightly lower GPx activity and higher SOD activity above reference values were determined. These indicators point to energy deficit, as well as poor grazing quality, and a lack of selenium in pasture plant species. When determining the blood metabolic profile of lactating Travnik ewes, the obtained results of the research should be considered, and they should be included in the development of reference values for the Travnik sheep breed.

Indicators of cellular metabolism alterationsin patients with traumatic disease due to hypoxia, depending on a management regimen of intensive care

The aim of this study was to evaluate changes in the level of erythrocyte metabolism under conditions of hypoxia in patients with traumatic disease in polytrauma depending on the components of intensive care (IC). Materials and methods. A prospective study was carried out in 88 patients suffering from polytrauma in the period from 2015 to 2017. All the patients were divided into 2 groups, comparable by severity of trauma and condition. A special feature of the examined patients was the staged surgical correction in all cases according to the Damage Control concept. Patients from the Control group received an intensive care according to the standard local clinical protocol in polytrauma. Patients randomized to the FDP group were treated with infusion of D-fructose-1,6-diphosphate sodium hydrate in addition to the standard care. Hemodynamic parameters and cellular metabolism indicators were monitored: on admission to the operating room, after 24 hours, on day 3, 5 and 14. Results. The signs of hypovolemia were equally severe in both groups on admission to the operating room. The FDP group demonstrated more rapid stabilization of hemodynamics and improved myocardial contractility at the 3rd day of IC. The monitoring of acid-base balance and carbohydrate metabolism showed the presence of compensated metabolic acidosis and energy deficiency. High indexes of lactate/pyruvate indicated a sharp imbalance in the ratio of aerobic/anaerobic metabolic processes. The analysis of ATP dynamics displayed impaired mitochondrial ATP production and inhibition of the glycolytic pathway of energy release. Conclusions. Complementary systemic inflammatory response with the elevation of lactate level by the 5th day occurred in patients with traumatic disease who underwent staged surgical correction. Optimization of intensive care resulted in a faster restoration of the balance between aerobic and anaerobic metabolic processes, an increase in the level of ATP and the rate of 2,3-DPG production in erythrocytes contributing to adequate oxygen supply to the tissues, supporting cellular respiration and preventing the development of oxidative tissue damage, as well as helped to maintain compensatory mechanisms and reduce cellular hypoxia ensuring adequate metabolism of vital organs.

Периоперационная инфузионная терапия у детей младшего возраста с ургентной абдоминальной патологией

Безопасная инфузионная терапия у детей требует глубокого понимания основных принципов, основанных на особенностях водно-электролитного обмена и кислотно-основного состояния в детском возрасте. Содержание воды и электролитов в организме ребенка поддерживается в очень узких пределах, поэтому необходимо понимать потенциальные физиологические эффекты нарушений баланса воды и растворенных в ней веществ, так как эти изменения всегда сопровождают периоперационный период. Периоперационная инфузионная терапия имеет прямое влияние на клинический результат лечения, в связи с чем ее назначение должно соответствовать потребностям больного. Целью инфузионной терапии у больных детей в периоперационном периоде является поддержка эффективного циркулирующего объема и недопущение, где только возможно, интерстициальной перегрузки жидкостью. Кроме знаний физиологии и патофизиологии водно-электролитного обмена в детском возрасте, для адекватной инфузионной терапии необходимо понимание фармакологии инфузионных препаратов, их дозировки, техники применения, нарушение которых может негативно сказаться на прогнозе заболевания. Именно поэтому целью нашего исследования стало изучение изменений гемодинамических показателей, водно-электролитного, кислотно-щелочного обменов при применении различных инфузионных растворов в периоперационном периоде. Работа выполнена на основе анализа лечения 55 пациентов младшего возраста с ургентной абдоминальной патологией, которые в зависимости от вида проведения периоперационной инфузионной терапии были разделены на 3 группы: 1-я группа — дети, у которых в качестве инфузионной терапии в периоперационном периоде использовали гипотонические глюкозо-солевые растворы; 2-я группа — дети, у которых использовали раствор Рингера лактат; 3-я группа — дети, у которых использовали сбалансированный электролитный раствор Рингера малат. Исследование показало, что у детей с острой ургентной абдоминальной патологией отмечается обезвоживание организма и абсолютная гиповолемия, которая ухудшается развитием гипоосмолярного состояния, а для быстрой нормализации гемодинамических показателей, водно-электролитного обмена, кислотно-щелочного состояния и водных секторов организма оптимальной инфузионной средой должен быть сбалансированный солевой раствор с добавлением аспартата и малата.

John W. Severinghaus, M.D., 1922 to 2021.

John W. Severinghaus, M.D., 1922 to 2021.