During high-intensity (HI) exercise, metabolic acidosis significantly impairs exercise performance. Increasing the body\'s buffering capacity through training and exogenous intake of alkalizing supplements may improve high-intensity performance. Manipulating water and diet intake may influence the acid-base balance. The aim of this study was to determine the effects of mineral water rich in bicarbonate ions (STY) or placebo water (PLA) on circulating biomarkers and anaerobic performance and to verify whether alkalizing (ALK) or acidizing (ACI) diet would modulate these effects. Twenty-four athletes, assigned either to ALK (n = 12) or ACI (n = 12) diet for four weeks, completed a 1-min rowing Wingate Test in a double-blind and randomized trial after one week of daily hydration (1.5 to 2L/d) with either STY or PLA. Blood samples were taken before and after each test, and urine samples were collected each week. Chronic consumption of bicarbonate-rich water significantly impacted resting urinary pH irrespective of alkalizing or acidizing dietary intake. STY induced a significant increase in blood pH, lactate, and HCO3 - ion concentration post-exercise compared to PLA. Similar changes were observed when STY was associated with the ALK diet. In contrast, STY combined with the ACI diet only significantly affected urine pH and peak blood lactate compared to PLA (p < 0.05). No effect of bicarbonate-rich water was reported on anaerobic performance (p > 0.05). Our results suggest that consumption of bicarbonate-rich water alters acid-base balance during a warm-up and after HI exercise, could potentiate beneficial effects of an alkalizing diet on the acid-base balance after HI exercise, and reduces the acid load induced by an acidifying diet.

UNASSIGNED: To determine cardiotocographic patterns in newborns with metabolic acidosis, based on clinical signs of neurological alteration (NA) and the need for hypothermic treatment.
UNASSIGNED: All term newborns with metabolic acidosis in a single center from 2016 to 2020 were included in the study. Three segments of intrapartum CTG (cardiotocography) were considered (first 30 min of active labor, 90 to 30 min before birth, and last 30 min before delivery) and a longitudinal analysis of CTG pattern was performed according to the 2015 FIGO classification.
UNASSIGNED: Three hundred and twenty-four neonates with metabolic acidosis diagnosed at birth were divided into three groups: the first group included all neonates with any clinical sign of neurological alteration, requiring hypothermia according to the recommendation of the Italian Society of Neonatology (group TNA-Treated neurological Alteration, n = 17), the second encompassed neonates with any clinical sign of neurological alteration not requiring hypothermia (group NTNA-Not Treated neurological Alteration, n = 83), and the third enclosed all neonates without any sign of clinical neurological involvement (group NoNA-No neurological Alteration, n = 224). The most frequent alterations of CTG in TNA group were late decelerations, reduced variability, bradycardia, and tachysystole. Unexpectedly, from the longitudinal analysis of the CTG, 49% of all cases with metabolic acidosis never showed a pathological CTG with normal trace at the beginning of labor followed by normal or suspicious trace in the final part of labor, the same as in TNA and NTNA groups (10 and 39%, respectively).
UNASSIGNED: CTG has limited specificity in identifying cases of acidosis at birth, even in babies who will develop NA.

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 a short 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 a kidney transplant are a further specific group in the case of emergencies.
UNASSIGNED: Notfälle in der Nephrologie sind im Wesentlichen akute Situationen, in denen eine vitale Gefährdung des Patienten vorliegt. Hinzugezählt werden müssen aber auch Konstellationen, die in kurzer Zeit eine deutliche Verschlechterung der Nierenfunktion mit drohender dauerhafter Dialysepflichtigkeit mit sich bringen. Unmittelbarer Ausdruck einer verschlechterten Nierenfunktion ist das akute Nierenversagen, das unter Anwendung der Acute-Kidney-Injury-Network(AKIN)-Stadien beschrieben und pathophysiologisch in eine prärenale, renale und postrenale Genese eingeteilt wird. Dieses Nierenversagen manifestiert sich in Veränderungen des Volumen‑, Säure-Basen- und Elektrolythaushaltes. Die Termini nephrotisch und nephritisch beschreiben die Erscheinungsform der Nierenschädigung und helfen bei der Festlegung weiterführender Diagnostik. Besonderheiten hinsichtlich des Notfallgeschehens ergeben sich darüber hinaus in der Gruppe der terminal Nierenkranken, die bereits dialysieren oder einer Transplantation unterzogen wurden.

Lactic acidosis occurs from an overproduction of lactate or decreased metabolism. It is common in critically ill patients, especially those with hematological conditions such as multiple myeloma, leukemia, and lymphoma. There are two types of lactic acidosis, Type A and Type B, with Type B presenting more commonly in hematological conditions that require prompt diagnosis and treatment of the underlying condition. We present a case of a 43-year-old male with Type B lactic acidosis secondary to stage IV colon cancer with metastasis to the liver. Initial laboratory work was significant for lactic acid of 16.52 mmol/L. Arterial blood gas (ABG) showed pH 7.26, pCO2 21 mmHg, pO2 111 mmHg, and HCO3 9 mEq/L, revealing an anion gap and metabolic acidosis with compensatory respiratory alkalosis. Initially, the patient was treated with aggressive fluid management, IV antibiotics, and sodium bicarbonate; however, his lactic acid continued to rise. The recommendation was made for urgent dialysis. Despite treatments, the prognosis is poor.

While metabolic acidosis is one of the most common complications in patients with chronic kidney disease (CKD), there are several uncommon etiologies that are challenging to diagnose. Here, we describe a patient on peritoneal dialysis who developed high anion gap metabolic acidosis secondary to acquired 5-oxoprolinemia from acetaminophen use. While CKD is a known risk factor for developing this potentially serious complication, this case further highlights how 5-oxoproline accumulation can occur, even with therapeutic dosing of acetaminophen.

Anaerobic exercise decreases systemic pH and increases metabolic acidosis in athletes, altering the acid-base homeostasis. In addition, nutritional recommendations advising athletes to intake higher amounts of proteins and simple carbohydrates (including from sport functional supplements) could be detrimental to restoring acid-base balance. Here, this specific nutrition could be classified as an acidic diet and defined as \'Westernized athletic nutrition\'. The maintenance of a chronic physiological state of low-grade metabolic acidosis produces detrimental effects on systemic health, physical performance, and inflammation. Therefore, nutrition must be capable of compensating for systemic acidosis from anaerobic exercise. The healthy gut microbiota can contribute to improving health and physical performance in athletes and, specifically, decrease the systemic acidic load through the conversion of lactate from systemic circulation to short-chain fatty acids in the proximal colon. On the contrary, microbial dysbiosis results in negative consequences for host health and physical performance because it results in a greater accumulation of systemic lactate, hydrogen ions, carbon dioxide, bacterial endotoxins, bioamines, and immunogenic compounds that are transported through the epithelia into the blood circulation. In conclusion, the systemic metabolic acidosis resulting from anaerobic exercise can be aggravated through an acidic diet, promoting chronic, low-grade metabolic acidosis in athletes. The individuality of athletic training and nutrition must take into consideration the acid-base homeostasis to modulate microbiota and adaptive physiological responses.

Background: The ability of hemoglobin to bind and dissociate oxygen is crucial in delivering oxygen to tissues and is influenced by a range of physiological states, compensatory mechanisms, and pathological conditions. This may be illustrated by the oxyhemoglobin dissociation curve (ODC). The key parameter for evaluating the oxygen affinity to hemoglobin is p50. The aim of this study was to evaluate the impact of hemodialysis on p50 in a group of patients with chronic kidney disease (CKD). An additional goal was to assess the correlation between p50 and the parameters of erythropoiesis, point-of-care testing (POCT), and other laboratory parameters. Methods: One hundred and eighty patients (106 male, 74 female), mean age 62.5 ± 17 years, with CKD stage G4 and G5 were enrolled in this cross-sectional study. Patients were divided into two groups, including 65 hemodialysis (HD) patients and 115 patients not receiving dialysis (non-HD). During the standard procedure of arteriovenous fistula creation, blood samples from the artery (A) and the vein (V) were taken for POCT. The causes of CKD, as well as demographic and comorbidity data, were obtained from medical records and direct interviews. Results: The weekly dose of erythropoietin was higher in HD patients than in non-HD patients (4914 ± 2253 UI vs. 403 ± 798 UI, p < 0.01), but hemoglobin levels did not differ between these groups. In the group of non-HD patients, more advanced metabolic acidosis (MA) was found, compared to the group with HD. In arterial and venosus blood samples, the non-HD group had significantly lower pH, pCO2 and HCO3-. This group had a higher proportion of individuals with MA with HCO3- < 22 mmol/L (42% vs. 24%, p < 0.01). The absolute difference of p50 in arterial and venous blood was determined using the formula Δp50 = (p50-A) - (p50-V). Δp50 was significantly higher in the HD group in comparison to non-HD (0.08 ± 2.05 mmHg vs. -0.66 ± 1.93 mmHg, p = 0,02). There was a negative correlation between pH and the p50 value in arterial (pH-A vs. p50-A, r = -0.56, p < 0.01) and venous blood (pH-V vs. p50-V, r = -0.45, p < 0.01). In non-HD patients, hemoglobin levels correlated negatively with p50 (r = -0.29, p < 0.01), whereas no significant relation was found in HD patients. Conclusions: The ODC in pre-dialysis CKD (non-HD) patients is shifted to the right due to MA, and this is an additional factor influencing erythropoiesis. Hemodialysis restores the natural differences in hemoglobin\'s dissociation characteristics in the arterial and venous circulation.

Diabetic ketoacidosis (DKA) is a severe complication of diabetes mellitus characterized by hyperglycemia, metabolic acidosis, and ketosis. We present a challenging case of euglycemic DKA secondary to fasting and urinary tract infection with acute renal failure in a 50-year-old woman. Despite normal random blood sugar levels, the patient exhibited clinical signs of DKA, leading to further investigation. High anion gap metabolic acidosis with hyperkalemia and abnormal renal function tests were identified. After hemodialysis, serum ketones were found to be highly positive, confirming the diagnosis. Prompt management led to a complete clinical and laboratory resolution. This case underscores the importance of considering DKA in patients with suggestive symptoms, even with normal blood sugar levels.

BACKGROUND: The beneficial effects of oral supplements with alkalinizing agents in patients with chronic kidney disease (CKD) have been limited to the severe stages. We investigated whether two types of supplements, sodium bicarbonate (SB) and potassium citrate/sodium citrate (PCSC), could maintain renal function in patients with mild-stage CKD.
METHODS: This was a single-center, open-labeled, randomized cohort trial. Study participants with CKD stages G2, G3a, and G3b were enrolled between March 2013 and January 2019 and randomly assigned by stratification according to age, sex, estimated glomerular filtration rate (eGFR), and diabetes. They were followed up for 6 months (short-term study) for the primary endpoints and extended to 2 years (long-term study) for the secondary endpoints. Supplementary doses were adjusted to achieve an early morning urinary pH of 6.8-7.2. We observed renal dysfunction or new-onset cerebrovascular disease and evaluated urinary surrogate markers for renal injury.
RESULTS: Overall, 101 participants were registered and allocated to three groups: standard (n = 32), SB (n = 34), and PCSC (n = 35). Two patients in the standard group attained the primary endpoints (renal stones and overt proteinuria) but were not statistically significant. There was one patient in the standard reduced eGFR during the long-term study (p = 0.042 by ANOVA). SB increased proteinuria (p = 0.0139, baseline vs. 6 months), whereas PCSC significantly reduced proteinuria (p = 0.0061, baseline vs. 1 year, or p = 0.0186, vs. 2 years) and urinary excretion of 8-hydroxy-2\'-deoxyguanosine (p = 0.0481, baseline vs. 6 months).
CONCLUSIONS: This study is the first to report supplementation of PCSC reduced intrarenal oxidative stress in patients with mild-stage CKD.

Normal-anion-gap metabolic acidosis (NAGMA) is a common but often under-recognised and poorly understood condition, especially by less-experienced clinicians. In adults, NAGMA might be an initial clue to a more significant underlying pathology, such as autoimmune diseases, hypergammaglobulinemia or drug toxicities. However, identifying the aetiology can be challenging due to the diverse processes involved in the development of acidosis. A better understanding of the pathophysiology of NAGMA can help treating physicians suspect and evaluate the condition early and reach the correct diagnosis. This article provides an overview of renal acid-base regulation, discusses the pathophysiological processes involved in developing NAGMA and provides a framework for evaluation to reach an accurate diagnosis.