Acid-base Changes Research Articles

Emergencies in nephrology

Emergencies in nephrology are mainly acute life-threatening situations for patients. Furthermore, one needs to consider constellations that are so damaging to the kidneys that the need for permanent dialysis develops within ashort period of time. Acute kidney failure as an immediate consequence is categorized using the Acute Kidney Injury Network (AKIN) stages and is pathophysiologically subdivided into pre-, intra- and post-renal. This leads to changes in volume status, acid base and electrolytes, while the terms nephrotic and nephritic describe the amount of kidney damage and help to choose diagnostic steps wisely. Patients that are already undergoing dialysis treatment or have received akidney transplant are afurther specific group in the case of emergencies.

Systemic acylcarnitine levels are affected in response to multiple injuries and hemorrhagic shock: An analysis of lipidomic changes in a standardized porcine model.

Along with recent advances in analytical technologies, tricarboxylic acid-cycle intermediates are increasingly identified as promising makers for cellular ischemia and mitochondrial dysfunction during hemorrhagic shock. For traumatized patients, the knowledge of the role of lipid oxidation substrates is sparse. In this study, we aimed to analyze the dynamics of systemic acylcarnitine (AcCa) release in a standardized polytrauma model with hemorrhagic shock. Fifty-two male pigs (50 ± 5 kg) were randomized into two groups: group isolated fracture was subject to a standardized femur shaft fracture, and group polytrauma was subject to a femur fracture, followed by blunt chest trauma, liver laceration, and a pressure-controlled hemorrhagic shock for 60 minutes. Resuscitation was performed with crystalloids. Fractures were stabilized by intramedullary nailing. Venous samples were collected at six time points (baseline, trauma, resuscitation, 2 hours, 4 hours, and 6 hours). Lipidomic analysis was performed via liquid chromatography coupled mass spectrometry. Measurements were collated with clinical markers and near-infrared spectrometry measurements of tissue perfusion. Longitudinal analyses were performed with linear mixed models, and Spearman's correlations were calculated. A p value of 0.05 was defined as threshold for statistical significance. From a total of 303 distinct lipids, we identified two species of long-chain AcCas. Both showed a highly significant ( p < 0.001) twofold increase after hemorrhagic shock in group polytrauma that promptly normalized after resuscitation. This increase was associated with a significant decrease of the base excess ( p = 0.005), but recovery after resuscitation was faster. For both AcCas, there were significant correlations with decreased muscle tissue oxygen delivery ( p = 0.008, p = 0.003) and significant time-lagged correlations with the increase of creatine kinase ( p < 0.001, p < 0.001). Our results point to plasma AcCas as a possible indicator for mitochondrial dysfunction and cellular ischemia in hemorrhagic shock. The more rapid normalization after resuscitation in comparison with acid base changes may warrant further investigation.

Amide proton transfer imaging in rats after heatstroke.

Metabolic acidosis is the most common acid-base change following heatstroke. This study aimed to evaluate the internal environment changes caused by heatstroke using amide proton transfer (APT) imaging. Nineteen male Sprague-Dawley rats were randomly divided into the control group (CTRL, n = 7) and the heatstroke group (HS, n = 12). All the rats underwent a 7.0-T MRI, which included T2-weighted imaging (T2WI) and APT imaging. Subsequently, the surviving HS group rats repeated the same magnetic resonance scanning after 25 days and were designated as the follow-up group (FU, n = 7). APT values were measured in the hippocampus, thalamus, and corpus callosum. The APT values of the three groups were statistically analyzed and found in the hippocampus (CTRL vs. HS, P = 0.011; CTRL vs. FU, P = 0.078; HS vs. FU, P = 0.484; η ² = 0.276), left thalamus (CTRL vs. HS, P = 0.004; CTRL vs. FU, P = 0.014; HS vs. FU, P = 0.822; η ² = 0.331), right thalamus (CTRL vs. HS, P = 0.003; CTRL vs. FU, P = 0.015; HS vs. FU P = 0.769; η ² = 0.336), and corpus callosum (CTRL vs. HS, P < 0.001; CTRL vs. FU, P = 0.005; HS vs. FU, P = 0.523; η ² = 0.437). APT imaging can be a viable and practical tool for diagnosing heatstroke and monitoring its progression.

Acid-Base Analysis in the Operating Room: A Bedside Stewart Approach.

The bedside Stewart approach to acid–base disorders is a simple, pragmatic tool that can assist anesthesiologists in analyzing and managing acid–base changes in the operating room, particularly metabolic acidosis.

Sodium glucose co-transporter-2 inhibitors in intensive care unit patients with type 2 diabetes: a pilot case control study

BackgroundSodium glucose co-transporter-2 (SGLT2) inhibitors improve long-term cardiovascular and renal outcomes in individuals with type 2 diabetes. However, the safety of SGLT2 inhibitors in ICU patients with type 2 diabetes is uncertain. We aimed to perform a pilot study to assess the relationship between empagliflozin therapy and biochemical, and clinical outcomes in such patients.MethodsWe included 18 ICU patients with type 2 diabetes receiving empagliflozin (10 mg daily) and insulin to target glucose range of 10–14 mmol/l according to our liberal glucose control protocol for patients with diabetes (treatment group). Treatment group patients were matched on age, glycated hemoglobin A1c, and ICU duration with 72 ICU patients with type 2 diabetes exposed to the same target glucose range but who did not receive empagliflozin (control group). We compared changes in electrolyte and acid–base parameters, hypoglycemia, ketoacidosis, worsening kidney function, urine culture findings, and hospital mortality between the groups.ResultsMedian (IQR) maximum increase in sodium and chloride levels were 3 (1–10) mmol/l and 3 (2–8) mmol/l in the control group and 9 (3–12) mmol/l and 8 (3–10) mmol/l in the treatment group (P = 0.045 for sodium, P = 0.059 for chloride). We observed no differences in strong ion difference, pH or base excess. Overall, 6% developed hypoglycemia in each group. No patient in the treatment group and one patient in the control group developed ketoacidosis. Worsening kidney function occurred in 18% and 29% of treatment and control group patients, respectively (P = 0.54). Urine cultures were positive in 22% of treatment group patients and 13% of control group patients (P = 0.28). Overall, 17% of treatment group patients and 19% of control group patients died in hospital (P = 0.79).ConclusionsIn our pilot study of ICU patients with type 2 diabetes, empagliflozin therapy was associated with increases in sodium and chloride levels but was not significantly associated with acid–base changes, hypoglycemia, ketoacidosis, worsening kidney function, bacteriuria, or mortality.

Research and evaluation on Water-dispersion resistance of synchronous grouting slurry in shield tunnel

When the shield tunnel passes through the watered stratum with high permeability, as the shield tail interspace prone to be filled with groundwater, resulting in the segregation and loss of ordinary grout slurry during synchronous grouting, then critically affect the physical and mechanical properties as well as the durability of the curing grouting ring. Hence, it is necessary to optimize the performance of the existing ordinary grouting slurry to improve its water-dispersion resistance on the premise of ensuring the original performance. By means of theoretical analysis and indoor tests, this paper systematically investigates the mechanism of water-dispersion resistance of synchronous grouting slurry in water-rich stratum with high permeability, establishing a set of testing process and detection method for water-dispersion resistance of synchronous grouting. Moreover, the influences of different flocculants with corresponding contents on the performance of synchronous grouting slurry have been revealed, and the evaluation criterion of water-dispersion resistance of synchronous grouting slurry in shield tunnel is also clarified. The results show that: 1) Turbidity has notable responses to the change of flocculant content, which could better reflect the clarity of water samples. So, the turbidity is considered as a main evaluation index of water-dispersion resistance of synchronous grouting; 2) On the other hand, pH and water-land strength ratio also demonstrates the acid-base changes of groundwater and the loss of cementitious materials respectively during grouting. Thus, the two indexes are applied as auxiliary evaluation indexes for water-dispersion resistance of synchronous grouting; 3) For the above evaluation indexes, corresponding critical values to satisfy the water-dispersion resistance of synchronous grouting slurry are ensured: turbidity < 100NTU, pH < 10, and water–air strength ratio at different curing ages greater than 80%.

Physicochemical Analysis of Mixed Venous and Arterial Blood Acid-Base State in Horses at Core Temperature during and after Moderate-Intensity Exercise.

Simple SummaryThe purposes of the present study were to determine the effect of core body temperature on acid-base variables and determine the origins of acid-base changes in the arterial and mixed venous blood of horses during exercise and recovery. Moderate intensity exercise resulted in an increase in body temperature that, in addition to exercise, affected acid-base status and gas partial pressures. Moderate intensity exercise resulted in a mild alkalosis that had markedly different origins in arterial blood than in mixed venous blood, and this was affected by the increase in core temperature during exercise and its resolution during recovery. In order to fully understand how acid-base status changes during exercise and recovery, it is importance to quantify the changes in both arterial and mixed venous blood, with adjustment to core temperature. Acid-base assessments using jugular vein blood samples are limited in comparison.The present study determined the independent contributions of temperature, strong ion difference ([SID]), total weak acid concentration ([Atot]) and PCO2 to changes in arterial and mixed venous [H+] and total carbon dioxide concentration ([TCO2]) during 37 min of moderate intensity exercise (~50% of heart rate max) and the first 60 min of recovery. Six horses were fitted with indwelling carotid and pulmonary artery (PA) catheters, had PA temperature measured, and had blood samples withdrawn for immediate analysis of plasma ion and gas concentrations. The increase in core temperature during exercise (+4.5 °C; p < 0.001) significantly (p < 0.05) increased PO2, PCO2, and [H+], but without a significant effect on [TCO2] (p > 0.01). The physicochemical acid-base approach was used to determine contributions of independent variables (except temperature) to the changes in [H+] and [TCO2]. In both arterial and venous blood, there was no acidosis during exercise and recovery despite significant (p < 0.05) increases in [lactate] and in venous PCO2. In arterial blood plasma, a mild alkalosis with exercise was due to primarily to a decrease in PCO2 (p < 0.05) and an increase in [SID] (p < 0.1). In venous blood plasma, a near absence of change in [H+] was due to the acidifying effects of increased PCO2 (p < 0.01) being offset by the alkalizing effects of increased [SID] (p < 0.05). The effect of temperature on PO2 (p < 0.001) resulted in an increased arterio-venous PO2 difference (p < 0.001) that would facilitate O2 transfer to contracting muscle. The simultaneous changes in the PCO2 and the concentrations of the other independent acid-base variables (contributions from individual strong and weak ions as manifest in [SID] and [Atot]) show complex, multilevel control of acid-base states in horses performing even moderate intensity exercise. Correction of acid-base variables to core body temperature presents a markedly different physiological response to exercise than that provided by variables measured and presented at an instrument temperature of 37 °C.

The biological activity and application of Monascus pigments: a mini review

Abstract Monascus pigments (MPs), as secondary metabolites of Monascus, are microbial pigments which have been used for thousands of years. MPs are widely used in food industry as food pigments and preservatives, which have the stability of light resistance, high temperature resistance and acid-base change resistance. In addition, the antioxidant, antibacterial, antiviral and anti-tumor biological activities of MPs have also attracted people’s attention. Moreover, Due to the presence of citrinin, the safety of MPs still needs to be discussed and explored. In this paper, the production, biological activity, application in various fields and methods of detection and reduction of citrinin of MPs were reviewed, which provide new insights into the study and safe application related to human different diseases, medicines or health care products with MPs as active substances.

Blood Inflammatory, Hydro-Electrolytes and Acid-Base Changes in Belgian Blue Cows Developing Parietal Fibrinous Peritonitis or Generalised Peritonitis after Caesarean Section.

This study aimed to describe the inflammation, hydro-electrolyte and acid-base imbalances caused by generalised peritonitis (GP) and parietal fibrinous peritonitis (PFP) after caesarean section. After clinical examination, blood was sampled from 11 cows with PFP, 30 with GP and 14 healthy cows. Serum and plasma refractometry and glutaraldehyde tests were used to evaluate the inflammation level, while hydro-electrolytes and acid-base parameters were assessed using an EPOC® device. In addition to clinical signs of dehydration (>10%), blood analysis showed a high fibrinogen concentration (PFP: 8.64 ± 8.82 g/L; GP: 7.83 ± 2.45 g/L) and fast glutaraldehyde coagulation (<3 min) indicative of severe inflammation in both diseases compared to the control group (p < 0.05). Moreover, a severe decrease in electrolytes concentration (Na+: 126.93 ± 5.79 mmol/L; K+: 3.7 ± 1.3 mmol/L; Ca++: 0.89 ± 0.12 mmol/L; Cl−: 82.38 ± 6.45 mmol/L) and a significant increase in bicarbonate (30.87 ± 8.16 mmol/L), base excess (5.71 ± 7.42 mmol/l), L-lactate (8.1 ± 4.85 mmol/L) and creatinine (3.53 ± 2.30 mg/dL) were observed in cows with GP compared to the control group (p < 0.05). In contrast, few major perturbations were noticed in PFP, where only K+ (3.64 ± 0.25 mmol/L) and Ca++ (1.06 ± 0.09 mmol/L) were significantly modified (p < 0.05). In conclusion, a high dehydration and severe inflammation are induced by PFP and GP. Nevertheless, GP causes more electrolytes and acid-base disturbances than PFP.

Reversibly stealth QR code based on N-methylmaleimide-vinyl acetate copolymers under the condition of acid-base change

The Quick Response (QR) code has been widely used in many fields. While the information security of users will be endangered, if the QR code is illegally duplicated. So, the stealth QR code has the potential application in security printing. In this paper, a kind of stealth QR code that can be reversibly displayed by N-methylmaleimide (MMI) and vinyl acetate (VAc) copolymers as inkpad under the condition of acid-base change. The PVAc/MMI copolymers were synthesized by solution polymerization in methanol using VAc and different amount of MMI (MMI:VAc = 1, 2, 3 and 4 mol%). Because there is a big difference of the reactivity ratio of MMI (rMMI = 1.16) and VAc (rVAc = 1.90 × 10−3), the MMI were starved feeding into the polymerization system at a fixed rate over a period of 3 h. The actual mole ratio of MMI units in copolymers are 0.70 mol%, 1.91 mol%, 3.03 mol% and 5.83 mol% corresponding to the feeding ratios of MMI:VAc from 1 mol% to 4 mol%, respectively. The PVAc/MMI copolymers can be become to PVA/MMI by alcoholysis. The thermal properties of PVAc/MMI and PVA/MMI were investigated. The introduction of MMI in copolymers are helpful for improving the glass transition temperature (Tg) of PVAc/MMI and PVA/MMI, decreasing melting points (Tm) of PVA/MMI. The interesting thing is that the colorless PVAc/MMI showed color change under base condition in the alcoholysis process, further, the color showed reversibly change under acid/base condition change. This feature inspires us that using PVAc/MMI copolymer solution as inks, a kind of QR code patterns can be realized with fast color response, from blue color in alkaline condition to achromatous in acidic condition, which confirms the superior information encryption ability of the chemical-based QR pattern. Based on this feature, the QR code stamped by PVAc/MMI copolymers can be reversibly displayed in the actual information encryption application.

Diagnosing metabolic acidosis in chronic kidney disease: importance of blood pH and serum anion gap.

Metabolic acidosis is one of the most common complications of chronic kidney disease (CKD). It is associated with the progression of CKD, and many other functional impairments. Until recently, only serum bicarbonate levels have been used to evaluate acid-base changes in patients with reduced kidney function. However, recent emerging evidence suggests that nephrologists should reevaluate the clinical approach for diagnosing metabolic acidosis in patients with CKD based on two perspectives; pH and anion gap. Biochemistry and physiology textbooks clearly indicate that blood pH is the most important acid-base parameter for cellular function. Therefore, it is important to determine if the prognostic impact of hypobicarbonatemia varies according to pH level. A recent cohort study of CKD patients showed that venous pH modified the association between a low bicarbonate level and the progression of CKD. Furthermore, acidosis with a high anion gap has recently been recognized as an important prognostic factor, because veverimer, a nonabsorbable hydrochloride-binding polymer, has been shown to improve kidney function and decrease the anion gap. Acidosis with high anion gap frequently develops in later stages of CKD. Therefore, the anion gap is a time-varying factor and renal function (estimated glomerular filtration rate) is a time-dependent confounder for the anion gap and renal outcomes. Recent analyses using marginal structural models showed that acidosis with a high anion gap was associated with a high risk of CKD. Based on these observations, reconsideration of the clinical approach to diagnosing and treating metabolic acidosis in CKD may be warranted.

Stewart analysis unmasks acidifying and alkalizing effects of ionic shifts during acute severe respiratory alkalosis.

Although both the Henderson-Hasselbalch method and the Stewart approach can be used to analyze acid-base disturbances and metabolic and respiratory compensation mechanisms, the latter may be superior in detecting subtle metabolic changes. We analyzed acid-base disturbances using both approaches in six healthy male volunteers practicing extreme voluntary hyperventilation. Arterial blood gas parameters were obtained during a breathing exercise consisting of approximately 30 cycles of powerful hyperventilation followed by breath retention for approximately 2 min. Hyperventilation increased pH from 7.39 ± 0.01 at baseline to 7.74 ± 0.06, PaCO2 decreased from 34.1 ± 1.1 to 12.6 ± 0.7 mmHg, PaO2 increased from 116 ± 4.6 to 156 ± 4.3 mmHg. Baseline apparent strong ion difference was 42.3 ± 0.5 mEq/L, which decreased to 37.1 ± 0.7 mEq/L following hyperventilation. The strong ion gap significantly decreased following hyperventilation, with baseline levels of 10.0 ± 0.9 dropping to 6.4 ± 1.1 mEq/L. Henderson-Hasselbalch analysis indicated a profound and purely respiratory alkalosis with no metabolic compensation following extreme hyperventilation. The Stewart approach revealed metabolic compensation occurring within minutes. These results challenge the long-held axiom that metabolic compensation of acute respiratory acid-base changes is a slow process.

Association of acidosis with coagulopathy and transfusion requirements in liver transplantation.

The relationship between acidosis and coagulopathy has long been described in vitro and in trauma patients, but not yet in orthotopic liver transplantation (OLT). The association of metabolic acidosis with coagulopathy and with transfusion requirements was evaluated in patients submitted to OLT. Changes in acid-base and coagulation parameters were analyzed by repeated measures. Regression analyses [adjusted for sex, age, model for end stage liver disease (MELD) score, and baseline values of hemoglobin, fibrinogen, international normalized ratio, platelets] determined the association of acid-base parameters with coagulation markers and transfusion requirement. We included 95 patients, 66% were male, 49.5% of the patients had hepatocellular carcinoma and the mean MELD score was 20.4 (SD 8.9). The values of all the coagulation and acid-base parameters significantly changed during OLT, particularly in the reperfusion phase. After adjustments for baseline parameters, the decrease in pH and base excess (BE) values were associated with a decrease in fibrinogen levels (mean decrease of fibrinogen level = 14.88mg/dL per 0.1 unit reduction of pH values and 3.6mg/dL per 1 mmol/L reduction of BE levels) and an increase in red blood cells transfusion (2.16 units of RBC per 0.1 unit reduction of pH and 0.38 units of RBC per 1 mmol/L reduction of BE levels). Among multiple factors potentially associated with adverse outcomes, decreasing pH levels were independently associated with the length of hospitalization but not with in-hospital mortality. Metabolic acidosis is independently associated with decreased fibrinogen levels and increased intraoperative transfusion requirement during OLT. Awareness of that association may improve treatment strategies to reduce intraoperative bleeding risk in OLT.

Comparison outcomes of percutaneous nephrolithotomy in prone and flank position in obese patients: A randomized clinical trial.

The aim of this study was to compare the complications of percutaneous nephrolithotomy (PCNL) surgery in Flank and Prone positions in patients with a BMI above 30. In this randomized clinical trial patients were randomly assigned to PCNL treatment in one of two groups undergoing PCNL under fluoroscopic guidance in Flank or Prone positions. Patient demographic information, stone number, size and location, stent duration, hospital stay, blood loss, Creatinine, hemoglobin, hematocrit changes, and arterial blood gas changes and acid-base hemostasis were collected. In this study, 60 patients were examined, which were divided into two groups of 29 people, prone and 31 people. Mean stone size was 3.16 ± 0.82 cm. arterial blood gases did not differ significantly between two groups. The SFR (stone free rate) in the prone and flank groups was 91.02% and 86.89%, respectively. However, SFR and Complications in the prone and flank groups were not significantly different (p value of 0.081 and 0.13, respectively). According to the results of this study, PCNL complications and acid-base changes is not significantly different in flank and prone positions in obese patients. However, SFR is slightly lower in flank group. Thus, PCNL in flank position is not superior to prone position in obese Patients. It is recommended to choose each of these surgical methods according to the surgeon's facilities and skills.

Precise Cancer Anti-acid Therapy Monitoring Using pH-Sensitive MnO2@BSA Nanoparticles by Magnetic Resonance Imaging.

Microfluctuations in a pH gradient create a harsh microenvironment in tumors, leaving behind the most aggressive, invasive, and drug-resistant tumor cells. Directly visualizing the spatiotemporal distribution of pH variations and accurately quantifying the dynamic acid-base changes during cancer treatment are critical to estimate prognosis and to evaluate therapeutic efficacy. However, the quantification of subtle pH variations dynamically and noninvasively remains challenging. The purpose of this study is to determine and visualize dynamic acid-base changes in solid tumors during anti-acid treatments by magnetic resonance imaging (MRI) using pH-sensitive nanoparticles. We report the development of pH-sensitive nanoparticles, MnO2@BSA, that rapidly and strongly amplify the MR contrast signal in response to the extracellular acidic environment of solid tumors. The spatiotemporal distribution and dynamic fluctuations of pH heterogeneity in NCI-H460 lung tumors were observed with MnO2@BSA at different time points after an anti-acid treatment with esomeprazole, which directly interferes with the acidic microenvironment of the tumor. Imaging results were validated using a pH microsensor. MRI of pH-sensitive MnO2@BSA nanoparticles provided direct readouts of the kinetics of pH gradient fluctuations during esomeprazole treatment. A significant MR signal reduction was observed at the 48 h time point after treatment. The manipulated extracellular pH changes detected noninvasively by MRI coincided with the extracellular pH fluctuations measured with a pH microsensor (pH 6.12-6.63). Immunofluorescence and Western blot analyses confirmed the expression of V-ATPase in NCI-H460 lung cancer cells, which could be inhibited by esomeprazole, as detected by ELISA assay. Overall, these results demonstrate that MnO2@BSA MRI has great potential as a noninvasive tool to accurately monitor pH fluctuations, thereby paving the way for the dynamic detection of acidic microenvironments in vivo without the need for pH microsensors.

Effects of Prior Voluntary Hyperventilation on the 3-min All-Out Cycling Test in Men.

The ergogenic effects of respiratory alkalosis induced by prior voluntary hyperventilation (VH) are controversial. This study examined the effects of prior VH on derived parameters from the 3-min all-out cycling test (3MT). Eleven men ( = 46 ± 8 mL·kg-1·min-1) performed a 3MT preceded by 15 min of rest (CONT) or VH ( = 38 ± 5 L·min-1) with PETCO2 reduced to 21 ± 1 mm Hg (HYP). End-test power (EP; synonymous with critical power) was calculated as the mean power output over the last 30 s of the 3MT, and the work done above EP (WEP; synonymous with W') was calculated as the power-time integral above EP. At the start of the 3MT, capillary blood PCO2 and [H+] were lower in HYP (25.2 ± 3.0 mm Hg, 27.1 ± 2.6 nmol·L-1) than CONT (43.2 ± 2.0 mm Hg, 40.0 ± 1.5 nmol·L-1) (P < 0.001). At the end of the 3MT, blood PCO2 was still lower in HYP (35.7 ± 5.4 mm Hg) than CONT (40.6 ± 5.0 mm Hg) (P < 0.001). WEP was 10% higher in HYP (19.4 ± 7.0 kJ) than CONT (17.6 ± 6.4 kJ) (P = 0.006), whereas EP was 5% lower in HYP (246 ± 69 W) than CONT (260 ± 74 W) (P = 0.007). The ΔWEP (J·kg-1) between CONT and HYP correlated positively with the PCO2 immediately before the 3MT in HYP (r = 0.77, P = 0.006). These findings suggest that acid-base changes elicited by prior VH increase WEP but decrease EP during the all-out 3MT.

Fluid Management in Kidney Disease Patients for Nontransplant and Transplantation Surgeries

Abstract Kidneys play an essential role in the regulation of water homeostasis, electrolyte balance, and acid–base balance. Anesthesiologists are frequently involved in the perioperative care of patients with kidney disease in elective and emergency scenarios. Fluid therapy is a main component of resuscitation to improve cardiac output, blood pressure, and perfusion pressure. This sometimes comes at a cost of increased risk of tissue edema due to fluid overload. Both during the transplant and nontransplant surgeries, the use or choice of fluid may influence the biochemical environment or homeostasis of human body and clinical outcomes. In this narrative review, we address the electrolyte and acid–base changes in renal disease, pharmacology of fluids, hemodynamic monitoring, and their applications.

Clinical, Hematological, Blood Gasometric and Electrolytic Changes in Dogs Receiving Whole Blood Transfusions

Background: Blood transfusion is a tool capable of saving lives. Patients undergoing blood transfusion usually present several alterations in the acid-base and electrolyte balance, aggravating the condition of critically ill patients. Some studies have demonstrated haematological alterations in certain species that received whole blood transfusions, however, few studies have evaluated acid base and electrolyte changes in dogs undergoing whole blood haemotherapy. The aim of this study was to analyze clinical, hematological, blood gas and electrolyte changes in anemic dogs after whole blood transfusion.Materials, Methods &amp; Results:Twenty nine dogs transfused due to anemia were enrolled in the study. Donors blood was collected in a transfusion bag containing citrate phosphate adenine dextrose and stored up to 24 h. Blood collections and evaluations were made before and 24 h after the transfusion. Data distribution normality was tested by the Shapiro Wilk Test. The means of the variables were compared by paired t-test. It was observed an increase in diastolic blood pressure and a reduction in heart rate (P &lt; 0.05). There was a not significant increase in systolic blood pressure, temperature, and a reduction in respiratory rate per minute. Erythrocyte, haemoglobin and haematocrit averages were significantly increased after blood transfusion (P &lt; 0.05). It was observed a reduction in the mean values of pH (P &lt; 0.05), potassium (P &gt; 0.05) and ionized calcium (P &gt; 0.05) and an increase in the mean partial pressure of carbon dioxide (pCO2) (P &lt; 0.001), bicarbonate (P &gt; 0.05) and sodium (P &lt; 0.05). The probable cause of anemia was monocytic ehrlichiosis (14/29), visceral leishmaniasis (1/29), babesiosis (1/29), co-infection of Ehrlichia canis and Leishmaniainfantum (2/19), co-infection of E. canis and Babesia vogeli (1/19). It was not possible to determine the etiology of the anemia in ten dogs. Discussion:Heart rate significantly reduced after transfusion, probably because of the increase in hematocrit, hemoglobin and erythrocyte values. It may be justified by the displacement of extravascular fluid to the intravascular space. Mean values of systolic blood pressure were slightly elevated before transfusion and remained elevated afterwards, while diastolic and mean arterial pressure increased significantly after transfusion. These changes may be due to the morbid condition and may be influenced by many other factors. Haematocrit, haemoglobin and erythrocyte values increased significantly after transfusion, according to what was observed in other studies. The significant reduction in pH and increase in pCO2 reflects the compensatory mechanism for metabolic acidosis to increase ventilation, leading to pCO2 reduction and changes in pH. The reduction in pH due to the contact of the collected blood with conservative solutions is one of the main changes thar occurs during blood storage. It was described significantly lower pH in dogs’ whole blood samples stored for more than 24h in vacutainer plastic containing CPDA-1. We may assume there was no intense pH reduction in the present study because the bags were stored for up to 24 h. Although not statistically significant, the increase of pO2 mean reflects the improvement of tissue oxygen perfusion. It was observed a significant increase in sodium ions. The mean sodium ionconcentration before transfusion was very close to the maximum reference value. Hyperkalaemia was not observed, nor was there significant reduction of potassium ions after transfusion. Several studies report hyperkalaemia and transfusion-associated cardiac arrests in humans, associated with infusion of large volumes of blood. Whole blood transfusion increased erythrogram values and did not negatively affect the electrolyte or acid-base status, representing a safe and useful tool in the intensive care of small animals.

Pollution and Ecological Risk Assessment and Source Apportionment of Heavy Metals in Sediments of Qingliangshan Reservoir in the Meijiang Basin

Reservoir sediment is an important sink for pollutants such as heavy metals. Under the changes in acid-base and redox conditions, there is a potential risk of heavy metals release into the water environment, which are transmitted through the food chain and threaten human health. Therefore, this study investigates the Qingliangshan Reservoir in the Meijiang River Basin, and conducts research concerning the contents and speciation of heavy metals in the sediments, potential ecological risks, and source apportionment. This study found that the content of heavy metals in the sediments of the reservoir area was in the order:Xitian tributary > dam front and reservoir center > Xintian-Baishui tributary. There is a large difference in the speciation of heavy metals in the sediments. Zn is mainly acid-soluble and in the residual state, Pb is mainly in an Fe/Mn oxide bound state, Cd is mainly in an acid-soluble state, and Cu, Ni, and Cr are in the residual state. Mainly, the percentage of bioavailable states are Cd(89%) > Pb(76%) > Zn(54%) > Cu(43%) > Ni(28%) > Cr(10%). The geoaccumulation index method shows that the pollution degree of heavy metal elements in reservoir sediments is in the order Cd > Pb > Zn > Cu > Cr > Ni, and the potential hazard ecological index method shows that the pollution degree of heavy metals is Cd > Pb > Cu > Ni > Zn > Cr. The potential ecological risk of Cd in the reservoir sediments is the largest, and the biological impact is greatest. Correlation analysis and principal component analysis results show that heavy metals Cu, Zn, Pb, and Cd in reservoir sediments are mainly from agricultural pollution, and Ni and Cr are mainly from natural background. Combined with the analysis of soil heavy metal content in the watershed, heavy metal pollution in the Qingliangshan Reservoir sediments originates from the effect of rainfall runoff and the use of agricultural chemical fertilizers before flooding in the upstream of the reservoir tributaries. There are significant spatial differences in heavy metal pollution in the sediments of the reservoir area. The Xintian-Baishui River recharge area is the least polluted, and it is closely related to the land use in the controlled watershed, which is mainly forest land, with fewer sources of pollution. The Xitian River replenishment area has the heaviest pollution. It controls many tea gardens and farmlands in the watershed, and the load of external fertilizer pollution is the largest. The pollution degree of heavy metals in front of the dam and the center of the reservoir area is between the two tributary replenishment areas, showing an obvious mixing effect.

Mechanisms of Peritoneal Acid-Base Kinetics During Peritoneal Dialysis: A Mathematical Model Study.

To investigate mechanisms of acid-base changes during peritoneal dialysis (PD), a mathematical model was developed that describes kinetics of peritoneal bicarbonate, CO2, and pH during the dwell with both high and low lactate-containing dialysis fluids. The model was based on a previous modification of the Rippe 3-Pore model of water and solute kinetic transport across the peritoneal membrane during the PD dwell. A central feature of the present modification is an electroneutrality constraint on peritoneal-fluid ion concentrations, which results in the conclusion that peritoneal bicarbonate-concentration kinetics are entirely dependent on the kinetics of the other ions. This new model was able to closely predict peritoneal bicarbonate-concentration kinetics during the dwell. Predictions of total peritoneal bicarbonate-mass kinetics were greater than those of porous, transmembrane bicarbonate transport, suggesting that a portion of bicarbonate comes from CO2 transport, both porous and nonporous and then a partial conversion to bicarbonate. Fitting the model to experimental pH data during the dwell, required addition of a peritoneal CO2 mass-conservation constraint, coupled with the description for peritoneal bicarbonate kinetics. Predicted pH kinetics during the dwell, closely mimicked the experimental data. The conclusion was that the mechanisms describing peritoneal bicarbonate and pH kinetics during PD must include 1) electroneutrality of peritoneal fluid, 2) porous transport of bicarbonate and CO2, 3) nonporous transport of CO2, and 4) CO2 conversion to bicarbonate. These mechanisms are quite different and more complex than the bicarbonate-centered, lactate to acid-generation mechanisms previously proposed.