Sodium citrate versus sodium bicarbonate for metabolic acidosis in patients with chronic kidney disease: A randomized controlled trial

BACKGROUND

Metabolic acidosis (MA) is frequently associated with chronic kidney disease (CKD) progression. Our aim was to compare the effect of oral sodium citrate (SC) with that of oral sodium bicarbonate (SB) on renal function and serum bicarbonate correction, as well as to evaluate their safety profile in patients with MA of CKD.

METHODS

We conducted a prospective, single-center, randomized 1:1, parallel, controlled, unblinded clinical trial of 124 patients with MA and CKD stages 3b and 4. The primary outcome was the mean change in estimated glomerular filtration rate (eGFR). The secondary outcomes were mean change in serum bicarbonate level, eGFR decrease by 30%, eGFR decrease by 50%, dialysis, death or prolonged hospitalization, and a combined endpoint.

RESULTS

No significant difference was found between the groups in terms of mean eGFR change [adjusted mean difference = -0.99 mL/min/1.73 m2 (95% CI: -2.51 to 0.93, P = .20)]. We observed a mean serum bicarbonate change of 6.15 mmol/L [(95% CI: 5.55-6.74), P < .001] in the SC group and of 6.19 mmol/L [(95% CI: 5.54-6.83), P < .001] in the SB group, but no significant difference between the 2 groups [adjusted mean difference = 0.31 mmol/L (-0.22 to 0.85), P = .25]. Cox proportional hazard analysis showed similar risks regarding eGFR decrease by 30% (P = .77), eGFR decrease by 50% (P = .50), dialysis (P = .85), death or prolonged hospitalization (P = .29), and combined endpoint (P = .57). Study drug discontinuation due to adverse events was significantly more common in the SB group (17.7% vs 4.8%, P = .02).

CONCLUSIONS

SC and SB have a similar effect on kidney function decline, both improve serum bicarbonate level, but SB is associated with higher rates of medication discontinuation due to adverse events.

Prevalence, Risk Factors, and Management of Metabolic Acidosis in Chronic Kidney Disease Patients: A Multicenter Retrospective Study in Malaysia

Background Metabolic acidosis in chronic kidney disease (CKD) patients has lately gained attention due to the growing evidence of its treatment benefits. This study aims to provide baseline data on the prevalence, risk factors, and current management of metabolic acidosis among the pre-dialysis adult Malaysian CKD population. Methodology This multicenter cross-sectional retrospective study involved pre-dialysis CKD patients above 18 years old on regular nephrology clinic follow-up at three Malaysian government hospitals with nephrology subspecialty. Demographic data, clinical information, laboratory data, and a list of concomitant medications were collected. Factors associated with the occurrence of metabolic acidosis were identified via multiple logistic regression. Results Six hundred and fifty-seven CKD patients were screened for this study, in which only 39.4% (n=259) had available bicarbonate levels. From this, a total of 86.1% (n=223) had metabolic acidosis. Higher estimated glomerular filtration rate (odds ratio (OR) 0.96, 95% confidence interval (CI) 0.93-1.00, p=0.043) and those with cardiovascular disease (OR 0.33, 95% CI 0.15-0.73; p=0.007) were significantly associated with lower odds of metabolic acidosis. There were 43.0% (n=96) on alkali therapy with sodium bicarbonate solution being the most common (n=91, 94.8%). Among those receiving alkali therapy, only 19.8% (n=19) achieved bicarbonate levels of ≥ 22 mEq/L. Conclusion Our study showed that metabolic acidosis was highly prevalent, although few achieved target levels despite supplementation, supporting the need for focused management of metabolic acidosis in the CKD population.

The Role of the Endocrine System in the Regulation of Acid-Base Balance by the Kidney and the Progression of Chronic Kidney Disease

Systemic acid-base status is primarily determined by the interplay of net acid production (NEAP) arising from metabolism of ingested food stuffs, buffering of NEAP in tissues, generation of bicarbonate by the kidney, and capture of any bicarbonate filtered by the kidney. In chronic kidney disease (CKD), acid retention may occur when dietary acid production is not balanced by bicarbonate generation by the diseased kidney. Hormones including aldosterone, angiotensin II, endothelin, PTH, glucocorticoids, insulin, thyroid hormone, and growth hormone can affect acid-base balance in different ways. The levels of some hormones such as aldosterone, angiotensin II and endothelin are increased with acid accumulation and contribute to an adaptive increase in renal acid excretion and bicarbonate generation. However, the persistent elevated levels of these hormones can damage the kidney and accelerate progression of CKD. Measures to slow the progression of CKD have included administration of medications which inhibit the production or action of deleterious hormones. However, since metabolic acidosis accompanying CKD stimulates the secretion of several of these hormones, treatment of CKD should also include administration of base to correct the metabolic acidosis.

Low Consciousness in a Patient with Pancolitis

Teaching point: Lentiform fork sign is a rare finding on MRI of the brain, found in patients with metabolic acidosis, in a critically ill patient with low consciousness and renal failure, this sign can correspond to uremic encephalopathy.

Perianesthetic metabolic acidosis is associated with 2% dorzolamide eye drops in dogs that underwent ophthalmic surgery: a retrospective study (2019-2022)

OBJECTIVE

To evaluate whether the administration of 2% dorzolamide ophthalmic solution in dogs undergoing ophthalmic surgery is associated with perianesthetic metabolic acidosis.

ANIMALS

60 dogs, with or without dorzolamide administration, underwent arterial blood gas analysis immediately after anesthesia for ophthalmic surgery between 2019 and 2022; a total of 60 surgeries were evaluated.

METHODS

This was a retrospective cross-sectional study. Logistic regression analysis was performed to investigate the association between the administration of 2% dorzolamide ophthalmic solution in dogs and the development of metabolic acidosis. Additionally, the influence of various potential risk factors, including age, body weight, sex, use of topical or systemic NSAIDs, and preoperative medications on the occurrence of metabolic acidosis, was evaluated.

RESULTS

A significant association was found between the use of 2% dorzolamide ophthalmic solution and perianesthetic metabolic acidosis (OR, 6.79; 95% CI, 2.00 to 23.02; P = .002). Furthermore, topical dorzolamide administration was significantly associated with both perianesthetic hypokalemia (OR, 3.52; 95% CI, 1.11 to 11.20; P = .033) and perianesthetic hyperchloremia (OR, 9.25; 95% CI, 1.71 to 50.01; P = .010).

CLINICAL RELEVANCE

The use of 2% dorzolamide ophthalmic solution is associated with perianesthetic metabolic acidosis, hypokalemia, and hyperchloremia in dogs. It is prudent to be aware of these risks, especially before anesthesia.

Trimethoprim inhibits renal H+-K+-ATPase in states of K+ depletion

There is growing consensus that under physiological conditions, collecting duct H+ secretion is independent of epithelial Na+ channel (ENaC) activity. We have recently shown that the direct ENaC inhibitor benzamil acutely impairs H+ excretion by blocking renal H+-K+-ATPase. However, the question remains whether inhibition of ENaC per se causes alterations in renal H+ excretion. To revisit this question, we studied the effect of the antibiotic trimethoprim (TMP), which is well known to cause K+ retention by direct ENaC inhibition. The acute effect of TMP (5 µg/g body wt) was assessed in bladder-catheterized mice, allowing real-time measurement of urinary pH, electrolyte, and acid excretion. Dietary K+ depletion was used to increase renal H+-K+-ATPase activity. In addition, the effect of TMP was investigated in vitro using pig gastric H+-K+-ATPase-enriched membrane vesicles. TMP acutely increased natriuresis and decreased kaliuresis, confirming its ENaC-inhibiting property. Under control diet conditions, TMP had no effect on urinary pH or acid excretion. Interestingly, K+ depletion unmasked an acute urine alkalizing effect of TMP. This finding was corroborated by in vitro experiments showing that TMP inhibits H+-K+-ATPase activity, albeit at much higher concentrations than benzamil. In conclusion, under control diet conditions, TMP inhibited ENaC function without changing urinary H+ excretion. This finding further supports the hypothesis that the inhibition of ENaC per se does not impair H+ excretion in the collecting duct. Moreover, TMP-induced urinary alkalization in animals fed a low-K+ diet highlights the importance of renal H+-K+-ATPase-mediated H+ secretion in states of K+ depletion.NEW & NOTEWORTHY The antibiotic trimethoprim (TMP) often mediates K+ retention and metabolic acidosis. We suggest a revision of the underlying mechanism that causes metabolic acidosis. Our results indicate that TMP-induced metabolic acidosis is secondary to epithelial Na+ channel-dependent K+ retention. Under control dietary conditions, TMP does not per se inhibit collecting duct H+ secretion. These findings add further argument against a physiologically relevant voltage-dependent mechanism of collecting duct H+ excretion.

Pseudohypoaldosteronism Type II or Gordon Syndrome: A Rare Syndrome of Hyperkalemia and Hypertension With Normal Renal Function

Pseudohypoaldosteronism type II (PHA II) or Gordon syndrome is characterized by hyperkalemia, hypertension, hyperchloremic metabolic acidosis, low plasma renin activity, and normal kidney function. We report a rare case of a young adult female patient presenting with abdominal pain, diarrhea, and vomiting. She was hypertensive during the presentation. Blood work showed mild anemia, hyperkalemia, hyperchloremia, and metabolic acidosis, with normal renal function and liver function. Plasma renin activity and aldosterone levels were low-normal. These findings were suggestive of PHA II or Gordon syndrome. It is a rare familial disease, with a non-specific presentation and no specific diagnostic criteria, and physicians should suspect it in patients with hyperkalemia in the setting of normal glomerular filtration, along with hypertension (which can be absent), metabolic acidosis, hyperchloremia, low plasma renin activity, and relatively suppressed aldosterone.

Marked Metabolic Acidosis Due to a Transverse Stoma after Urethroplasty for Congenital Epispadias

A 58-year-old woman was admitted to our hospital. At 10 years old, she had undergone bilateral uretero-sigmoid anastomosis for congenital epispadias, and at 57 years old, she had received transverse colostomy. Biochemical tests showed marked metabolic acidosis. Computed tomography showed urine stagnation in the sigmoid colon, leading to a diagnosis of metabolic acidosis associated with transverse stoma after bilateral uretero-sigmoid anastomosis. Her bone mineral density was below normal, and the bone metabolic marker levels were high, indicating high-turnover osteoporosis. Both metabolic acidosis and bone metabolism were stabilized by treatment with a transanal urinary catheter, sodium bicarbonate, and vitamin D.

Naturally Bicarbonated Water Supplementation Does Not Improve Anaerobic Cycling Performance or Blood Gas Parameters in Active Men and Women

The completion of high-intensity exercise results in robust perturbations to physiologic homeostasis, challenging the body's natural buffering systems to mitigate the accumulation of metabolic by-products. Supplementation with bicarbonate has previously been used to offset metabolic acidosis, leading to improvements in anaerobic exercise performance.

PURPOSE

The purpose of this study was to investigate the presence of ergogenic properties in naturally occurring low-dose bicarbonated water and their effects on anaerobic cycling performance and blood gas kinetics in recreationally active men and women.

METHODS

Thirty-nine healthy, recreationally active men and women (28.1 ± 8.0 years, 169.8 ± 11.7 cm, 68.9 ± 10.8 kg, 20.1 ± 7.9% fat, V˙O2peak: 42.8 ± 7.6 mL/kg/min) completed two separate testing sessions consisting of 15 cycling sprints (10 s sprint, 20 s active rest) against 7.5% of their body mass. Using a randomized, double-blind, placebo-controlled, parallel group study design, study participants consumed a 10 mL/kg dose of either spring water (SW) or bicarbonated mineral water (BMW) (delivering ~3 g/day of bicarbonate) for 7 days. Venous blood was collected before, immediately after, and 5 and 10 min after the sprint protocol and was analyzed for lactate and a series of blood gas components. After the completion of 15 cycling sprints, averages of peak and mean power for bouts 1-5, 6-10, and 11-15, along with total work for the entire cycling protocol, were calculated. All performance and blood gas parameters were analyzed using a mixed-factorial ANOVA.

RESULTS

pH was found to be significantly higher in the BMW group immediately after (7.17 ± 0.09 vs. 7.20 ± 0.11; p = 0.05) and 10 min post exercise (7.21 ± 0.11 vs. 7.24 ± 0.09; p = 0.04). A similar pattern of change was observed 5 min post exercise wherein pH levels in the SW group were lower than those observed in the BMW group; however, this difference did not achieve statistical significance (p = 0.09). A statistical trend (p = 0.06) was observed wherein lactate in the BMW group tended to be lower than in the SW group 5 min post exercise. No significant main effect for time (p > 0.05) or group × time interactions (p > 0.05) for the total work, average values of peak power, or average values of mean power were observed, indicating performance was unchanged.

CONCLUSION

One week of consuming water with increased bicarbonate (10 mL/kg; ~3 g/day bicarbonate) showed no effect on anaerobic cycling performance. BMW decreased blood lactate concentrations 5 min after exercise and increased blood pH immediately and 10 min after exercise.

Complications Secondary to the Use Of Sglt2 Inhibitors in Oncological Patients: A Series of 5 Cases

Sodium-glucose cotransporter-2 (iSGLT2) inhibitors, which include dapagliflozin, canagliflozin and empagliflozin, are a class of drugs initially used in the oral treatment of diabetes, heart failure and renal failure. They target the reabsorption of glucose in the kidney. Although they bring benefit to patients with these conditions and in general produce few adverse effects, in some cases, iSGLT2 can cause serious adverse effects such as metabolic acidosis, and fungal or bacterial urinary infections. Oncology patients, who in general have a weak immune system and are usually treated with chemotherapy and/or immunotherapy, are more susceptible to this type of adverse events than other patients. For this reason, it is necessary to adequately select the patients eligible to receive this type of drug and evaluate the potential benefits for them. In this series of five cases, we present two cases of metabolic acidosis, two cases of bacterial urinary sepsis, and one case of fungal urinary sepsis that occurred in patients admitted to the Medical Oncology Department of the University Hospital of Salamanca in 2023.

LEARNING POINTS

Adverse events associated with iSGLT2 can lead to serious complications in immunocompromised patients. There have been cases of prolonged admissions with high morbidity and mortality due to bacterial or fungal infections and metabolic acidosis, all of which are side effects derived from their use.In oncology patients, an adequate evaluation of the risk-benefit balance must be conducted before the introduction of new drugs.Studies should be conducted to assess the risk of serious adverse effects in oncology patients undergoing treatment with chemotherapy or immunotherapy.

IV Colistin: A Rare Cause of Bartter-Like Syndrome in Adults

Bartter syndrome is a genetic condition characterized by autosomal recessive inheritance, resulting in impaired salt reabsorption and clinical manifestations such as low/normal blood pressure and extracellular fluid volume depletion. Multiple abnormalities of the electrolytes, including decreased potassium as well as chloride levels and, in some instances, hypomagnesemia, are its defining features. Metabolic alkalosis, hypokalaemia, hypocalcemia, and hypomagnesemia, together with adequate renal function, are all components of the Bartter-like syndrome. It is associated with certain antibiotics and antineoplastic drugs. We report a case of traumatic brain injury with pneumothorax who was on treatment on colistin and presented with metabolic disturbance.

Point-of-Care Testing to Differentiate Various Acid-Base Disorders in Chronic Kidney Disease

BACKGROUND

Normal-anion-gap metabolic acidosis (AGMA) and high-anion-gap metabolic acidosis (HAGMA) are two forms of metabolic acidosis, which is a common complication in patients with chronic kidney disease (CKD). The aim of this study is to identify the prevalence of various acid-base disorders in patients with advanced CKD using point-of-care testing (POCT) and to determine the relationship between POCT parameters.

METHODS

In a group of 116 patients with CKD in stages G4 and G5, with a mean age of 62.5 ± 17 years, a sample of arterial blood was taken during the arteriovenous fistula procedure for POCT, which enables an assessment of the most important parameters of acid-base balance, including: pH, base excess (BE), bicarbonate (HCO3-), chloride(Cl-), anion gap (AG), creatinine and urea concentration. Based on this test, patients were categorized according to the type of acidosis-base disorder.

RESULTS

Decompensate acidosis with a pH < 7.35 was found in 68 (59%) patients. Metabolic acidosis (MA), defined as the concentration of HCO3- ≤ 22 mmol/L, was found in 92 (79%) patients. In this group, significantly lower pH, BE, HCO3- and Cl- concentrations were found. In group of MA patients, AGMA and HAGMA was observed in 48 (52%) and 44 (48%) of patients, respectively. The mean creatinine was significantly lower in the AGMA group compared to the HAGMA group (4.91 vs. 5.87 mg/dL, p < 0.05). The AG correlated positively with creatinine (r = 0.44, p < 0.01) and urea (r = 0.53, p < 0.01), but there was no correlation between HCO3- and both creatinine (r = -0.015, p > 0.05) and urea (r = -0.07, p > 0.05). The Cl- concentrations correlated negatively with HCO3- (r = -0.8, p < 0.01).

CONCLUSIONS

The most common type of acid-base disturbance in CKD patients in stages 4 and 5 is AGMA, which is observed in patients with better kidney function and is associated with compensatory hyperchloremia. The initiation of renal replacement therapy was significantly earlier for patients diagnosed with HAGMA compared to those diagnosed with AGMA. The more advanced the CKD, the higher the AG.

Spontaneous Bilateral Basal Ganglia Haemorrhage Secondary to Methanol Poisoning

Methanol toxicity remains as major problem in the medical field.[1],[2],[3] With its active metabolite, formic acid often leads to severe metabolic acidosis and to some extend brain damaged.[4],[5],[6] We are reporting a case of brain hemorrhage at the right external capsule and left basal ganglia with mass effect and obstructive hydrocephalus in a methanol poisoning patient. A confused 29-year-old gentleman was brought into hospital. Initial investigation showed severe metabolic acidosis with raised anion gap. Initial brain CT scan was normal. Subsequently, serum methanol was reported to be high (112 mg/dL). Intravenous (IV) ethanol 10% was given without any delayed. As there was no improvement in his consciousness level, a repeat brain CT was performed and it showed multiple cerebral hemorrhage with obstructive hydrocephalus. Hence, clinicians should have high index of suspicion for cerebral hemorrhage in a patient with methanol toxicity, who presented with altered mental status and severe metabolic acidosis.

Isovaleric Acidemia: A Case Report

Isovaleric acidemia is an autosomal recessive disease of leucine metabolism. The clinical presentation is variable and three phenotypes are described, asymptomatic, acute neonatal, and chronic intermittent. Infections are the most important trigger for catabolic crises. Diagnosis is based on the detection of isovalerylglycine CoA in urine and elevated levels of isovaleryl (C5) carnitine in blood. Long-term treatment consists of prevention of catabolic state, dietary restriction, and supplementation with L-carnitine and/or L-glycine. We present the case of a three-year-old female patient with multiple episodes of decompensation since the age of two years. The episode in which she was diagnosed had encephalopathy, with no neurological sequelae. Currently, the patient continues with dietary restrictions and supplementation with good nutritional and growth results for her age.

The effects of oral sodium bicarbonate supplementation on anthropometric measures in patients with chronic kidney disease: A systematic review and meta-analysis of randomized clinical trials

Metabolic acidosis (MA) may play a key role in the pathogenesis of protein-energy wasting (PEW) in patients with chronic kidney disease (CKD). To present a comprehensive synthesis of the effect of oral sodium bicarbonate (SB) supplementation on anthropometric measures in patients with CKD, a systematic review was undertaken in PubMed/MEDLINE, Web of Science, Cochrane CENTRAL, and Google Scholar, of relevant articles published prior to September 2022. The summary statistics of effect size, nonstandardized weighted mean difference (WMD), and 95% confidence interval (CI) were used to compare the effects of SB supplementation on anthropometric parameters vs. control group. To detect probable sources of heterogeneity, a series of predefined subgroup analyses were conducted. In total, 17 studies with 21 treatment arms, including 2203 participants (1149 cases, 1054 controls), met our inclusion criteria and were included in the meta-analysis. SB supplementation had no significant effect on body weight (BW), midarm muscle circumference (MAMC), or lean body mass (LBM) in patients with CKD. There was a significant increase in body mass index (BMI) (MD: 0.59 kg/m2, 95% CI: 0.25 to 0.93, p = 0.001) after SB supplementation in the overall analysis. In subgroup analysis, LBM was increased in studies that were ≥ 24-week duration (MD: 1.81 kg, 95% CI: 0.81 to 2.81) and in participants with BMI lower than 27 kg/m2 (MD: 1.81 mg/L, 95% CI: 0.81 to 2.81). SB supplementation may yield increases in BMI in predialysis CKD patients. However, our findings did not support the beneficial effects of SB supplementation on other anthropometric outcomes. There is an evident need for long-term high-quality interventions to confirm these findings.

Study on the Common Molecular Mechanism of Metabolic Acidosis and Myocardial Damage Complicated by Neonatal Pneumonia

Pneumonia is a common clinical disease in the neonatal period and poses a serious risk to infant health. Therefore, the understanding of molecular mechanisms is of great importance for the development of methods for the rapid and accurate identification, classification and staging, and even disease diagnosis and therapy of pneumonia. In this study, a nontargeted metabonomic method was developed and applied for the analysis of serum samples collected from 20 cases in the pneumonia control group (PN) and 20 and 10 cases of pneumonia patients with metabolic acidosis (MA) and myocardial damage (MD), respectively, with the help of ultrahigh-performance liquid chromatography-high-resolution mass spectrometry (UPLC-HRMS). The results showed that compared with the pneumonia group, 23 and 21 differential metabolites were identified in pneumonia with two complications. They showed high sensitivity and specificity, with the area under the curve (ROC) of the receiver operating characteristic curve (ROC) larger than 0.7 for each differential molecule. There were 14 metabolites and three metabolic pathways of sphingolipid metabolism, porphyrin and chlorophyll metabolism, and glycerophospholipid metabolism existing in both groups of PN and MA, and PN and MD, all involving significant changes in pathways closely related to amino acid metabolism disorders, abnormal cell apoptosis, and inflammatory responses. These findings of molecular mechanisms should help a lot to fully understand and even treat the complications of pneumonia in infants.

Development and Characterization of Interstitial-Fluid-Mimicking Solutions for Pre-Clinical Assessment of Hypoxia

Asphyxia, a leading cause of illness and death in newborns, can be improved by early detection and management. Arterial blood gas (ABG) analysis is commonly used to diagnose and manage asphyxia, but it is invasive and carries risks. Dermal interstitial fluid (ISF) is an alternative physiological fluid that can provide valuable information about a person's health. ISF is more sensitive to severe hypoxia and metabolic disorders compared to blood, making it an attractive option for minimally invasive asphyxia detection using biosensors. However, obtaining ISF samples from humans is challenging due to ethical concerns and sampling difficulties. To address this, researchers are developing ISF-mimicking solutions as substitutes for early testing and evaluation of biosensors. This paper focuses on the development of these solutions for bench-based testing and validation of continuous asphyxia-monitoring biosensors. With an understanding of the factors influencing system quality and performance, these solutions can aid in the design of biosensors for in vivo monitoring of dermal ISF. Monitoring interstitial fluid pH levels can provide valuable insights into the severity and progression of asphyxia, aiding in accurate diagnosis and informed treatment decisions. In this study, buffer solutions were prepared to mimic the pH of ISF, and their electrical properties were analyzed. The results suggest that certain buffers can effectively mimic metabolic acidosis associated with asphyxia (pH < 7.30), while others can mimic metabolic alkalosis (pH > 7.45). Overall, this research contributes to the development of ISF-mimicking solutions and lays the groundwork for biosensor systems that monitor dermal ISF in real time.

Dose-dependent relationship between SGLT2 inhibitor hold time and risk for postoperative anion gap acidosis: a single-centre retrospective analysis

BACKGROUND

Use of sodium-glucose transporter-2 (SGLT2) inhibitors has dramatically increased over the past decade. This medication class predisposes patients to euglycaemic diabetic ketoacidosis, particularly during times of physiologic stress, including fasting and surgery. Beyond case reports and series, a systematic description of perioperative metabolic effects of SGLT2 inhibitors is lacking.

METHODS

We examined the degree of anion gap acidosis, controlling for non-ketone anions, in patients undergoing surgery at Massachusetts General Hospital in 2016-22. We constructed a multivariable regression model incorporating known non-ketone contributors to the postoperative anion gap (albumin, lactate, estimated glomerular filtration rate, and preoperative anion gap), hold time, and interaction terms between hold time and three previously suggested risk factors for euglycaemic diabetic ketoacidosis: emergency surgery, cardiac surgery, and insulin use.

RESULTS

In 463 patients on SGLT2 inhibitors, we observed a strong association between decreased hold time and postoperative anion gap (P<0.001 in a univariable analysis; -0.43, 95% confidence interval [-0.76 to -0.11] change in anion gap per day held, P=0.01 in a multivariable analysis). A significant interaction between hold time and emergency surgery was observed, whereas there was no apparent interaction with insulin use or cardiac surgery.

CONCLUSIONS

These findings provide the first evidence that an anion gap acidosis, likely from ketoacids, develops in all patients who do not hold SGLT2 inhibitors before surgery rather than in an idiosyncratic few. If an SGLT2 inhibitor is unable to be stopped, postoperative monitoring of anion gap and serum ketones can help detect clinically significant euglycaemic diabetic ketoacidosis, particularly in those undergoing emergency surgery.

An Elderly Case of Altered Metabolic Profile Presenting With Respiratory Distress: A Radical Display

Acute respiratory distress syndrome (ARDS) is a pulmonary pathology that itself can harm and further lead to many other significant hazardous sequelae. Pulmonary vasculature can be distressed by several diseases, but among all the causes, sepsis is one of the main culprits. Its consequences include significant alveolar injury, refractory hypoxemia, ventilation-perfusion mismatch, and destruction of the alveolar-capillary membrane. Dyspnea with diffuse infiltration on a chest X-ray is the most prevalent clinical symptom. Here, we discuss a case of a 62-year-old male patient who presents with ARDS and metabolic anomalies. The patient was treated medically with drug regimens.

A Spanish Family with Gordon Syndrome Due to a Variant in the Acidic Motif of WNK1

(1) Background: Gordon syndrome (GS) or familial hyperkalemic hypertension is caused by pathogenic variants in the genes WNK1, WNK4, KLHL3, and CUL3. Patients presented with hypertension, hyperkalemia despite average glomerular filtration rate, hyperchloremic metabolic acidosis, and suppressed plasma renin (PR) activity with normal plasma aldosterone (PA) and sometimes failure to thrive. GS is a heterogeneous genetic syndrome, ranging from severe cases in childhood to mild and sometimes asymptomatic cases in mid-adulthood. (2) Methods: We report here a sizeable Spanish family of six patients (four adults and two children) with GS. (3) Results: They carry a novel heterozygous missense variant in exon 7 of WNK1 (p.Glu630Gly). The clinical presentation in the four adults consisted of hypertension (superimposed pre-eclampsia in two cases), hyperkalemia, short stature with low body weight, and isolated hyperkalemia in both children. All patients also presented mild hyperchloremic metabolic acidosis and low PR activity with normal PA levels. Abnormal laboratory findings and hypertension were normalized by dietary salt restriction and low doses of thiazide or indapamide retard. (4) Conclusions: This is the first Spanish family with GS with a novel heterozygous missense variant in WNK1 (p.Glu630Gly) in the region containing the highly conserved acidic motif, which is showing a relatively mild phenotype, and adults diagnosed in mild adulthood. These data support the importance of missense variants in the WNK1 acidic domain in electrolyte balance/metabolism. In addition, findings in this family also suggest that indapamide retard or thiazide may be an adequate long-standing treatment for GS.

Navigating a Complex Presentation: Management of Hypernatremic Dehydration, Acute Kidney Injury, Hyperkalemia, and Metabolic Acidosis in a Patient With Down Syndrome: A Case Report

Worldwide, gastroenteritis is a well-known cause of dehydration in pediatric patients and can be life-threatening due to subsequent electrolyte disturbance or dehydration itself. In this case, we present an infant with Down syndrome (karyotype: 21 trisomy) who presented to us with moderate hypernatremic dehydration associated with severe hyperkalemia, moderate metabolic acidosis (pH: 7.1, random blood glucose: 80-110 mg/dL), and elevated kidney function tests secondary to the gastroenteritis caused by Entamoeba histolytica infection. The patient is being followed up by the pediatrics genetics clinic for growth and development, with regular screening for thyroid and celiac diseases, and he has no major heart, gastrointestinal, or renal anomalies. This unique and complex presentation of electrolyte disturbance and dehydration associated with a susceptible condition of Down syndrome deserves special attention with precise management which can be challenging. We managed the patient as a case of hypernatremic dehydration with gradual correction of serum sodium and dehydration, while concurrently managing hyperkalemia by routine methods (beta agonist inhalers, insulin, dextrose 10%) with close laboratory and clinical monitoring at the pediatric intensive care unit. The pediatric nephrology team was also consulted while delineating the management plan. As the patient's condition eventually resolved with normal kidney function and electrolytes, metabolic acidosis also resolved, with good oral intake and urine output, stable vitals, and was discharged after 72 hours. In conclusion, this case showed that pediatric patients with susceptible conditions such as Down syndrome with gastroenteritis can present with a lethal combination of dehydration and/or electrolyte disturbance, making close monitoring and prompt management paramount in such cases.

Pharmacological Nephroprotection in Non-Diabetic Chronic Kidney Disease-Clinical Practice Position Statement of the Polish Society of Nephrology

Chronic kidney disease (CKD) is a modern epidemic worldwide. Introducing renin-angiotensin system (RAS) inhibitors (i.e., ACEi or ARB) not only as blood-pressure-lowering agents, but also as nephroprotective drugs with antiproteinuric potential was a milestone in the therapy of CKD. For decades, this treatment remained the only proven strategy to slow down CKD progression. This situation changed some years ago primarily due to the introduction of drugs designed to treat diabetes that turned into nephroprotective strategies not only in diabetic kidney disease, but also in CKD unrelated to diabetes. In addition, several drugs emerged that precisely target the pathogenetic mechanisms of particular kidney diseases. Finally, the role of metabolic acidosis in CKD progression (and not only the sequelae of CKD) came to light. In this review, we aim to comprehensively discuss all relevant therapies that slow down the progression of non-diabetic kidney disease, including the lowering of blood pressure, through the nephroprotective effects of ACEi/ARB and spironolactone independent from BP lowering, as well as the role of sodium-glucose co-transporter type 2 inhibitors, acidosis correction and disease-specific treatment strategies. We also briefly address the therapies that attempt to slow down the progression of CKD, which did not confirm this effect. We are convinced that our in-depth review with practical statements on multiple aspects of treatment offered to non-diabetic CKD fills the existing gap in the available literature. We believe that it may help clinicians who take care of CKD patients in their practice. Finally, we propose the strategy that should be implemented in most non-diabetic CKD patients to prevent disease progression.

Reducing Dietary Acid With Fruit and Vegetables Versus Oral Alkali in People With Chronic Kidney Disease (ReDACKD): A Clinical Research Protocol

Background

Individuals with chronic kidney disease (CKD) can develop metabolic acidosis which, in turn, is associated with faster progression of CKD and an increased need for dialysis. Oral sodium bicarbonate (the current standard of care therapy for metabolic acidosis) is poorly tolerated leading to low adherence. Base-producing or alkalizing Fruit and vegetables have potential as an alternative treatment for metabolic acidosis as they have been shown to reduce acid load arising from the diet.

Objective

This trial will evaluate the feasibility of providing base-producing fruit and vegetables as a dietary treatment for metabolic acidosis, compared with oral sodium bicarbonate.

Design

A 2-arm, open-label, dual-center, randomized controlled feasibility trial.

Setting

Two Canadian sites: a nephrology clinic in Winnipeg, Manitoba, and a nephrology clinic in Halifax, Nova Scotia.

Participants

Adult participants with G3-G5 CKD and metabolic acidosis.

Measurements

Participants will undergo baseline measurements and attend 5 study visits over 12 months at which they will have a measurement of feasibility criteria as well as blood pressure, blood and urine biochemistry, 5-repetition chair stand test (STS5), and questionnaires to assess quality of life and symptoms. Furthermore, participants fill out Automated Self-Administered 24-hour recalls (ASA-24) in the beginning, middle, and end of trial.

Methods

A total of 40 eligible participants will be randomized 1:1 to either base-producing fruit and vegetables (experimental) group or sodium bicarbonate (control) group, beginning from a daily dose of 1500 mg.

Limitations

Using self-administered dietary assessments, lack of supervision over the consumption of study treatments and the possible disappointment of the control group for not receiving fruit and vegetables would be considered as limitations for this study. However, we are planning to undertake proper practices to overcome the possible limitations. These practices are discussed throughout the article in detail.

Conclusions

This study will generate data on base-producing fruit and vegetables consumption as a dietary treatment for metabolic acidosis in CKD. The data will be used to design a future multi-center trial looking at slowing CKD progression in people with metabolic acidosis.

Trial Registration

This study is registered on clinicaltrials.gov with the identifier NCT05113641.

End-tidal carbon dioxide measured at emergency department triage outperforms standard triage vital signs in predicting in-hospital mortality and intensive care unit admission

OBJECTIVES

This study assessed the ability of end-tidal carbon dioxide (ETCO2 ) in predicting in-hospital mortality and intensive care unit (ICU) admission compared to standard vital signs at ED triage as well as comparing to measures of metabolic acidosis.

METHODS

This prospective study enrolled adult patients presenting to the ED of a tertiary care Level I trauma center over 30 months. Patients had standard vital signs measured along with exhaled ETCO2 at triage. Outcome measures included in-hospital mortality; ICU admission; and correlations with lactate, sodium bicarbonate (HCO3 ), and anion gap.

RESULTS

There were 1136 patients enrolled and 1091 patients with outcome data available. There were 26 (2.4%) patients who did not survive to hospital discharge. Mean ETCO2 levels were 34 (33-34) in survivors and 22 (18-26) nonsurvivors (p < 0.001). The area under the curve (AUC) for predicting in-hospital mortality for ETCO2 was 0.82 (0.72-0.91). In comparison the AUC for temperature was 0.55 (0.42-0.68), respiratory rate (RR) 0.59 (0.46-0.73), systolic blood pressure (SBP) 0.77 (0.67-0.86), diastolic blood pressure (DBP) 0.70 (0.59-0.81), heart rate (HR) 0.76 (0.66-0.85), and oxygen saturation (SpO2 ) 0.53 (0.40-0.67). There were 64 (6%) patients admitted to the ICU, and the ETCO2 AUC for predicting ICU admission was 0.75 (0.67-0.80). In comparison the AUC for temperature was 0.51, RR 0.56, SBP 0.64, DBP 0.63, HR 0.66, and SpO2 0.53. Correlations between expired ETCO2 and serum lactate, anion gap, and HCO3 were rho = -0.25 (p < 0.001), rho = -0.20 (p < 0.001), and rho = 0.330 (p < 0.001), respectively.

CONCLUSIONS

ETCO2 was a better predictor of in-hospital mortality and ICU admission than the standard vital signs at ED triage. ETCO2 correlated significantly with measures of metabolic acidosis.

A Review of Bicarbonate Use in Common Clinical Scenarios

BACKGROUND

The use of sodium bicarbonate to treat metabolic acidosis is intuitive, yet data suggest that not all patients benefit from this therapy.

OBJECTIVE

In this narrative review, we describe the physiology behind commonly encountered nontoxicologic causes of metabolic acidosis, highlight potential harm from the indiscriminate administration of sodium bicarbonate in certain scenarios, and provide evidence-based recommendations to assist emergency physicians in the rational use of sodium bicarbonate.

DISCUSSION

Sodium bicarbonate can be administered as a hypertonic push, as a resuscitation fluid, or as an infusion. Lactic acidosis and cardiac arrest are two common scenarios where there is limited benefit to routine use of sodium bicarbonate, although certain circumstances, such as patients with concomitant acute kidney injury and lactic acidosis may benefit from sodium bicarbonate. Patients with cardiac arrest secondary to sodium channel blockade or hyperkalemia also benefit from sodium bicarbonate therapy. Recent data suggest that the use of sodium bicarbonate in diabetic ketoacidosis does not confer improved patient outcomes and may cause harm in pediatric patients. Available evidence suggests that alkalinization of urine in rhabdomyolysis does not improve patient-centered outcomes. Finally, patients with a nongap acidosis benefit from sodium bicarbonate supplementation.

CONCLUSIONS

Empiric use of sodium bicarbonate in patients with nontoxicologic causes of metabolic acidosis is not warranted and likely does not improve patient-centered outcomes, except in select scenarios. Emergency physicians should reserve use of this medication to conditions with clear benefit to patients.

The practices of intravenous sodium bicarbonate therapy in neonatal intensive care units: A multi-country survey

A common occurrence in the neonatal intensive care unit (NICU) is metabolic acidosis. Sodium bicarbonate (SB) has been widely used, but there is insufficient evidence on how SB affects neonates in NICUs with metabolic acidosis. The worsening of intracellular acidosis, the impairment of myocardial function, fluctuations in cerebral blood flow, and intracranial hemorrhage are some of the unfavorable effects of SB treatment in neonates that have been documented in the literature. This study aimed to explore neonatologists' practices for using intravenous SB (ISB) in NICUs. A multi-country survey was carried out in 2022 using an online questionnaire sent to neonatologists in various countries in order to gather information about the use of ISB in NICUs. A previously validated questionnaire was adapted and used in this study. The response rate was 67%. The findings show that 91.2% of neonatologists were using SB to correct metabolic acidosis in the NICU; 71.4% did not have written guidelines for using sodium bicarbonate. The majority of them (78.9%) reported that dosage is included in their guidelines for the use of ISB. The findings of this study emphasize the critical importance of providing guidelines in using ISB for managing metabolic acidosis in NICU to standardize procedures and reduce the use of potentially unsuitable and unsafe treatments, as it has been shown that 71.4% of neonatologists worldwide use sodium bicarbonate without guidelines.

Fanconi Syndrome Associated with Long-term Treatment with Zoledronate

Intravenous bisphosphonate therapy is used to prevent fractures in the management of bone metastasis. However, it may induce renal damage. We herein report an 81-year-old woman with Fanconi syndrome and osteomalacia who had been diagnosed with metastatic breast cancer and received treatment with zolendronate for over 5 years. Her bone markers normalized after switching zolendronate to denosmab and starting vitamin D and mineral supplementation. This case shows that chronic renal damage induced by zolendronate can cause osteomalacia. In patients with intravenous zolendronate therapy, close monitoring of renal and bone markers is needed, even under long-term therapy.

Higher NICU admissions in infants born at ≥35 weeks gestational age during the COVID-19 pandemic

Background

Increasing evidence has shown that the COVID-19 pandemic has had a profound negative impact on vulnerable populations and a significant effect on maternal and neonatal health. We observed an increase in the percentage of infants admitted to NICU from 8% to 10% in the first year of the pandemic. This study aimed to compare the delivery room outcomes, NICU admissions and interventions, and neonatal outcomes two years before and during the pandemic.

Methods

This was a retrospective study in a public hospital between pre-COVID-19 (April 2018-December 2019) and COVID-19 (April 2020-December 2021). Data were obtained from all live births at ≥35 weeks gestation (GA). Maternal and neonatal demographics, delivery room (DR), and NICU neonatal outcomes were compared between the study periods using simple bivariable generalized estimating equations (GEE) regression. Multivariable GEE logistic regression analysis was performed to adjust for the effects of baseline differences in demographics on the outcomes.

Results

A total of 9,632 infants were born ≥35 weeks gestation during the study period (pre-COVID-19 n = 4,967, COVID-19 n = 4,665). During the COVID-19 period, there was a small but significant decrease in birth weight (33 g); increases in maternal diabetes (3.3%), hypertension (4.1%), and Hispanic ethnicity (4.7%). There was a decrease in infants who received three minutes (78.1% vs. 70.3%, p < 0.001) of delayed cord clamping and increases in the exclusive breastfeeding rate (65.9% vs. 70.1%, p < 0.001), metabolic acidosis (0.7% vs. 1.2%, p = 0.02), NICU admission (5.1% vs. 6.4%, p = 0.009), antibiotic (0.7% vs. 1.7%, p < 0.001), and nasal CPAP (1.2% vs. 1.8%, p = 0.02) use. NICU admissions and nasal CPAP were not significantly increased after adjusting for GA, maternal diabetes, and hypertension; however, other differences remained significant. Maternal hypertension was an independent risk factor for all these outcomes.

Conclusion

During the COVID-19 pandemic period, we observed a significant increase in maternal morbidities, exclusive breastfeeding, and NICU admissions in infants born at ≥35 weeks gestation. The increase in NICU admission during the COVID-19 pandemic was explained by maternal hypertension, but other adverse neonatal outcomes were only partly explained by maternal hypertension. Socio-economic factors and other social determinants of health need to be further explored to understand the full impact on neonatal outcomes.

[Analysis of surgical complications of reconstructive plastic surgery according to the ClavienDindo classification]

INTRODUCTION

The systematization of surgical complications has long been a serious problem since different types of surgical procedures have specific complications, in addition to general consequences. Created in 1992 and improved in 2004, the Clavien-Dindo classification was successfully validated in surgical centers in different countries and recognized as an important tool for the qualitative assessment of surgical complications.

AIM

To improve reconstructive procedures by systematizing complications based on the ClavienDindo classification.

MATERIALS AND METHODS

The results of substitution ileocystoplasty in 95 patients with contracted bladder due to tuberculosis and other diseases are presented. In 50 (52.6%) cases, the length of the bowel segment was 30-35 cm (group 1, main), while in 45 patients (47.4%) a segment of 45-60 cm was chosen (group 2, control).

RESULTS

Early complications of grade II developed in 11 (22.0%) patients in the group 1 and in 13 (28.9%) in group 2, while grade III in 5 (10.0%) and 6 (13.3%) cases, respectively. Complications of IIIb grade were seen among patients of the main group in 9 (18.0%) cases compared to 12 (26.7%) in the control group. Severe complications of IVa and IVb grades were documented with the same frequency in both groups, in one case each. Complications of V grade (death) were recorded only in the group 2. Late complications were registered in 63 out of 94 patients. In group 1, there were 26 complications (16 somatic and 10 surgical), while in group 2, a total of 37 complications (24 somatic and 13 surgical) were seen, which indicates a significant higher rate in the control group (p<0.05). In group 1, transurethral resection of urethral-enteric anastomosis and ureteral reimplantation were performed less frequently than in group 2, while transurethral resection of the prostate was done with the same frequency. At the same time, percutaneous nephrostomy was required more often in the group 1 (6% vs. 4.5% in the group 2). After intestinal cystoplasty with a shortened fragment of the ileum, the voiding volume was significantly lower but corresponded to the physiological value (more than 150 ml). In this group, there was sufficient capacity of neobladder with a minimum amount of residual urine, effective emptying, satisfactory urinary continence, and low intraluminal pressure, which contributes to the protection of kidneys from reservoir-ureteral-pelvic reflux. The serum chloride level after surgery was 106.2+/-0.4 in the group 1 compared to 109.7+/-0.3 in the group 2, while base excess was -0.93+/-0.3 and -3.4+/-0.65, respectively (p<0.05).

CONCLUSION

Early serious postoperative complications according to Clavien-Dindo were registered with approximately the same frequency in both groups, while late complications developed significantly more often in the group 2. The urodynamic parameters of a neobladder formed from ileum segment of 30-35 cm are satisfactory. In addition, a decrease in the length of the intestinal segment prevents the development of hyperchloremic metabolic acidosis.

Fulminant Neurologic Manifestation of Sjogren's Syndrome: A Case Report

Sjogren's syndrome (SS) is an autoimmune disorder characterized by the destruction of exocrine glands by lymphocytic infiltration. Children and teenagers are less commonly affected. The initial symptoms of SS in teenagers might vary, depending on whether parotitis or other systemic organ involvement is present. Glandular involvement with the clinical hallmarks of dry eyes and dry mouth is common. Our case report is about a young woman who was admitted with acute flaccid paralysis and severe respiratory distress with extremely low serum potassium; further investigation revealed distal renal tubular acidosis. The patient was ultimately diagnosed with primary SS with high levels of SS-a/SS-b antibodies and a positive Schirmer's test. Our case demonstrates that hypokalemic paralysis can be a manifestation of SS, even though it is a rare cause.

Enfortumab Vedotin-induced Hyperglycemia and Ileal Conduit Reconstruction-induced Metabolic Acidosis

We report a 76-year-old man who was treated for hyperglycemia and metabolic acidosis after chemotherapy with enfortumab vedotin and pembrolizumab administered after his surgery for bladder cancer. He had an approximately 20-year history of diabetes. His body mass index was 18.6, and he received metformin 1000 mg/day, sitagliptin 50 mg/day, mitiglinide 30 mg/day, and voglibose 0.6 mg/day with hemoglobin A1c was approximately 7%. He underwent total cystectomy and ileal conduit reconstruction. After relapse, he received chemotherapy but later developed hyperglycemia and metabolic acidosis. His hyperglycemia was caused by enfortumab vedotin, and metabolic acidosis was attributable to the ileocecal canal. These symptoms should be remembered as important complications of this standard treatment, which prompted this case report.

Association of serum bicarbonate with the development of kidney stones in patients with chronic kidney disease: a retrospective cohort study

BACKGROUND

Epidemiological studies demonstrate an association between kidney stones and risk of chronic kidney disease (CKD) and CKD progression. Metabolic acidosis, as a consequence of CKD, results in a reduced urine pH which promotes the formation of some types of kidney stones and inhibits the formation of others. While metabolic acidosis is a risk factor for CKD progression, the association of serum bicarbonate with risk of incident kidney stones is not well understood.

METHODS

We used an Integrated Claims-Clinical dataset of US patients to generate a cohort of patients with non-dialysis-dependent CKD with two serum bicarbonate values of 12 to <22 mmol/L (metabolic acidosis) or 22 to <30 mmol/L (normal serum bicarbonate). Primary exposure variables were baseline serum bicarbonate and change in serum bicarbonate over time. Cox proportional hazards models evaluated time to first occurrence of kidney stones during a median 3.2-year follow-up.

RESULTS

A total of 142 884 patients qualified for the study cohort. Patients with metabolic acidosis experienced post-index date kidney stones at greater frequency than patients with normal serum bicarbonate at the index date (12.0% vs 9.5%, P < .0001). Both lower baseline serum bicarbonate [hazard ratio (HR) 1.047; 95% confidence interval (CI) 1.036-1.057] and decreasing serum bicarbonate over time (HR 1.034; 95% CI 1.026-1.043) were associated with increased risk of kidney stone development.

CONCLUSIONS

Metabolic acidosis was associated with a higher incidence of kidney stones and shorter time to incident stone formation in patients with CKD. Future studies may investigate the role of correcting metabolic acidosis to prevent stone formation.

Increased newborn NICU admission for evaluation of hypoxic-ischemic encephalopathy during COVID-19 pandemic in a public hospital

Background

Prenatal and perinatal care of pregnant mothers has been adversely affected during the COVID-19 pandemic. Hypoxic-ischemic encephalopathy (HIE) is a leading cause of neonatal death and long-term neurological disabilities. Therapeutic hypothermia is effective for neonatal HIE. This study evaluated the effect of the pandemic on neonatal HIE.

Methods

This retrospective single-center study compared neonatal HIE evaluation and hypothermia treatment between pre-COVID-19 pandemic (1 January 2018-31 December 2019) and COVID-19 pandemic (1 January 2020-31 December 2021) periods. Infants with abnormal neurological examination and or significant metabolic acidosis were admitted to NICU for evaluation of HIE and therapeutic hypothermia. Demographics, NICU admission and interventions, and neonatal outcomes were compared between infants born during the two periods using χ², t-test, and Wilcoxon rank-sum test as appropriate. Statistical Process Control charts show the yearly proportion of infants evaluated for HIE and those treated with therapeutic hypothermia.

Results

From the pre-pandemic to the pandemic period, the proportion of infants that met HIE screening criteria increased from 13% to 16% (p < 0.0001), the proportion of infants admitted to NICU for HIE evaluation increased from 1% to 1.4% (p = 0.02), and the maternal hypertension rates of the admitted infants increased from 30% to 55% (p = 0.006). There was no difference in the proportions of the infants diagnosed with HIE (0.7% vs. 0.9%, p = 0.3) or treated with therapeutic hypothermia (0.2% vs. 0.3%, p = 0.3) between the two periods. There were no differences in the HIE severity and outcomes of the infants treated with therapeutic hypothermia between the two periods.

Conclusion

During the COVID-19 pandemic, we observed a significant increase in NICU admission for HIE evaluation. While we did not find significant increases in neonatal HIE and the need for therapeutic hypothermia, larger studies are needed for a comprehensive assessment of the impact of the COVID-19 pandemic on neonatal HIE.

Case Reports Study on Methanol Poisoning in King Abdul Aziz Specialist Hospital, Taif, Saudi Arabia

Methanol poisoning is a challenging issue due to its inducing acute multiple organ failures, and especially due to a lack of preparedness, available antidotes, and management protocols. The current study presents six cases of methanol poisoning that attended the emergency department of King Abdul Aziz Specialist Hospital, Taif, Saudi Arabia, between March and November 2022. All of the patients suffered from severe metabolic acidosis and visual impairment following the ingestion of homemade alcoholic beverages and colonia. Three patients were comatose, suffered from post-cardiac pulmonary arrest, and, finally, died, while the other three were non-comatose and discharged from the ICU after improvement. Management was based on clinical symptoms and other laboratory findings due to a shortage of methanol level measurement resources. The antidote, fomepizole, was not given to all of the cases due to its deficiency, and ethanol was given only to one patient due to difficulties in administering it without monitoring its concentration. Methanol poisoning and its outbreak provide insights into the dangers of hazardous homemade alcohol and other pharmaceutical preparations that might be adulterated with methanol, particularly to the shortage of suitable diagnostic testing and antidotes in addition to poor resources for management of intoxicated patients in some regions of Saudi Arabia.

A Diagnostic Dilemma "Cured" by Dialysis: An Educational Case Report

Rationale

The differential diagnosis for a patient with high-anion-gap metabolic acidosis (HAGMA) is broad; lactic acidosis is an important entity to screen for and treat. An elevated serum lactate is often used as a marker of inadequate tissue perfusion in critically ill patients but can also be indicative of decreased lactate utilization or poor hepatic clearance. Investigating for the underlying cause such as diabetic ketoacidosis, malignancy, or culprit medications is essential to establish the diagnosis and treatment plan.

Presenting concerns of the patient

A 60-year-old man with a history of substance use and end-stage kidney disease treated with hemodialysis presented to hospital with confusion, altered level of consciousness, and hypothermia. Initial laboratory investigations were significant for a severe HAGMA with elevated serum lactate and β-hydroxybutyrate levels, but toxicology screen was negative, and there was no clear underlying precipitant. Urgent hemodialysis was arranged to mitigate his severe acidosis.

Diagnoses

He had an initial single dialysis treatment for 4 hours, with posthemodialysis labs showing significant improvement in his acidosis, serum lactate level, and clinical status (cognition, hypothermia). Given this rapid resolution, a sample from his predialysis blood work was sent for analysis of plasma metformin and returned significantly elevated at 60 mcg/mL (therapeutic range 1-2 mcg/mL).

Interventions and outcomes

On careful medication reconciliation in the dialysis unit, the patient stated he had never heard of the medication metformin, and there was no record of a filled prescription at his pharmacy. Given his living situation with shared accommodations, it was presumed that he had taken medications that were prescribed to a roommate. Several of his other medications including his antihypertensives were subsequently given after dialysis on dialysis days to improve adherence.

Teaching points

Maintain a broad differential diagnosis for patients presenting with a clinical syndrome consistent with an acute toxicity even if no culprit medications are identifiable on history, especially in patients with a suggestive social history.Anion-gap metabolic acidosis (AGMA) is common in hospitalized patients but sometimes requires further history and/or confirmatory testing to elucidate the root cause underlying typical causes of AGMA such as lactic acidosis or ketoacidosis.The main treatment of metformin toxicity is resuscitation and supportive care; however, metformin's biochemical properties make it readily dialyzable via either diffusion or convection.The Extracorporeal Treatments In Poisoning group recommends hemodialysis for metformin toxicity when there is a serum lactate >20 mmol/L, a blood pH <7.0, a failure of standard therapy, end-organ damage (hepatic or renal insufficiency), or a decreased level of consciousness.

Outcome of Methanol Toxicity Outbreak In Saudi Arabia: Case Series Study

Introduction Methanol poisoning is an acute medical emergency. If not recognized in time and treated properly, it can lead to a considerable magnitude of morbidity as well as mortality. This article aims to report cases of methanol toxicity, focusing on clinical presentation, management, and outcomes. Method Nine ICU-admitted patients with confirmed positive serum methanol levels were analyzed in a case series at King Fahad General Hospital in Jeddah, Saudi Arabia, between November 2022 and January 2023. Results Among the nine patients admitted to the ICU due to methanol poisoning, the majority were middle-aged males, with two females included. Gastrointestinal symptoms were seen in two-thirds of patients, while three patients required immediate mechanical ventilation due to a low Glasgow Coma Scale. Severe metabolic acidosis was observed in most cases. All patients received sodium bicarbonate and hemodialysis, with six patients also receiving fomepizole. However, two patients in the study with low initial low Glasgow Coma Scale (GCS), severe metabolic acidosis, and diffuse brain edema, did not survive. One patient reported acute complete vision loss. Conclusion This case series highlights the importance of promptly recognizing and managing methanol toxicity in ICU settings. The clinical presentation of methanol toxicity can be challenging, and early diagnosis and treatment are crucial to prevent irreversible damage.

Starvation Ketoacidosis in a Young Healthy Female After Prolonged Religious Fasting

Ketone bodies are important energy sources for the body and are produced by the liver when the body is in a deficiency state of glucose, which is used in the peripheral tissues to provide energy. There are several ketone bodies that are produced by the liver, of which two are important: acetoacetate and beta-hydroxybutyrate. Even though ketone bodies are always present in the body, they are minimal when a person is not fasting. Ketone bodies are produced by the oxidation of fatty acids to fulfill the metabolic needs of tissues, especially the brain. The biochemical reactions of forming ketone bodies are triggered by a lack of insulin and an elevated glucagon level in the blood. Both cause unopposed lipolysis and free fatty acid oxidation resulting in the production of ketone bodies and eventually high anion gap metabolic acidosis. We present a case of young healthy female who presented with euglycemic ketoacidosis after involving prolonged fasting for her religious ceremony. She also physically exerted quite more during her fasting. With a detailed history and excluding other possibilities, we made the diagnosis of starvation ketoacidosis. She improved well with the treatment and established her pre-morbid condition in our review.

Serum Bicarbonate Deficiency in Dogs with Acute and Chronic Kidney Disease

Serum bicarbonate deficiency is a disorder frequently found in human patients with acute (AKI) and chronic (CKD) kidney disease, due to abnormalities in kidney generation and reabsorption of bicarbonate. Although alkali supplementation is usually performed in both humans and veterinary CKD patients, data regarding the frequency of bicarbonate disorders in AKI and CKD dogs are scarce. The aim of the present study is to assess the frequency and the severity of bicarbonate deficiency of dogs affected by AKI, acute chronic kidney disease (ACKD), and CKD, and to investigate its possible association with the IRIS grade/stage as well as with disorders of calcium phosphate metabolism. A retrospective evaluation of the serum biochemical panels of all dogs with diagnoses of AKI, ACKD, and CKD referred to the nephrology and urology service of the Veterinary Teaching Hospital of the University of Pisa, between January 2014 and January 2022, was performed. Bicarbonate deficiency was defined as serum bicarbonate < 22 mmol/L and classified as moderate (between 18 and 22 mmol/L) or severe (<18 mmol/L). Serum bicarbonate deficiency was found in 397/521 dogs (76%), of which 142/397 (36%) showed moderate deficiency, and 255/397 (64%) severe deficiency. Dogs with AKI and ACKD showed a significantly higher frequency of bicarbonate deficiency (p = 0.004) and severe forms compared to CKD dogs (p = 0.02). In AKI and ACKD dogs, a negative linear correlation was found between serum bicarbonate and serum creatinine, urea, and phosphate. The frequency of bicarbonate deficiency was higher in the later stages of the disease in both AKI (p = 0.01), ACKD (p = 0.0003), and CKD dogs (p = 0.009). Dogs with serum CaxP ≥ 70 mg²/dL² showed a higher frequency of bicarbonate deficiency (p = 0.01) and showed severe forms (p = 0.01) compared to dogs with CaxP < 70 mg²/dL². Serum bicarbonate deficiency seems to be a very frequent disorder in both AKI, ACKD, and CKD dogs, with an increasing frequency and severity in more advanced stages of kidney disease. The higher frequency and severity of bicarbonate deficiency in AKI and ACKD may be caused by a more severe and sudden loss of kidney function, or extra-renal factors. Finally, the association between frequency and severity of bicarbonate deficiency and abnormal CaxP may suggest a potential connection between metabolic acidosis and bone mineral disorders.

A Case of Severe Metabolic Acidosis in the Setting of a Strict Ketogenic Diet

Patients with metabolic acidosis often present with obscure, multifactorial etiologies, making efficient diagnosis and treatment key to preventing poor clinical outcomes. This case report describes a patient with severe metabolic acidosis in which the underlying cause was not immediately apparent. After a thorough work-up and history taking, the patient's strict ketogenic diet was identified as the most likely source of his illness. Over multiple days, the patient improved as he resumed a normal diet and was treated for refeeding syndrome. This case highlights the importance of taking a comprehensive social and diet history when assessing a patient with metabolic acidosis. It also highlights the need for physicians to understand and be ready to counsel on the possible effects of fad diets, such as the ketogenic diet.

Metformin-Associated Lactic Acidosis: A Case Report

Introduction

Metformin is considered a first-line therapy for patients with diabetes secondary to its cost efficiency, minimal side effects, and marked improvement in one's hemoglobin A1c; however, metformin is avoided in patients with renal insufficiency out of concern for drug accumulation and lactic acidosis. In fact, there is a black box warning for metformin, identifying lactic acidosis as the inciting trigger for fatal arrhythmias and death.

Case Presentation

A 62-year-old male presented with multiple episodes of nausea, vomiting, abdominal pain, and decreased urine output for 3 days after working on a roof, all day in the summer heat. He did not drink more than a bottle of water throughout that day and noted that afterward, he seemed to have little to no urine output. At presentation, he was in moderate distress due to abdominal pain and was diaphoretic, tachypneic, and hypertensive. The patient was given dextrose and started on a sodium bicarbonate drip. He was also given calcium gluconate. His mentation and respiratory status continued to decline throughout that day, and he required intubation and mechanical ventilation. The patient ultimately recovered quite rapidly upon receiving hemodialysis.

Conclusion

This case report shows the critical nature of identifying and quickly treating metformin toxicity.

Efficacy of sustained low-efficiency dialysis in the management of topiramate intoxication: case report

Guidelines on the use of dialysis treatment in patients with chronic kidney disease (CKD) and TPM (Topiramate) intoxication are controversial. A 51-year-old man with epilepsy and CKD was carried to our emergency department for dysuria and sickness. He chronically assumed TPM 100 mg 3/day. Creatinine level was 2.1 mg/dL, blood urea nitrogen 70 mg/dL, and inflammation indexes were increased. We started empirical antibiotic therapy and rehydration. The day two he had diarrhea and an acute insurgence of dizziness, confusion, and bicarbonate levels reduction. Brain CT resulted negative for acute events. During the night his mental status worsened, and urinary output results were about 200 mL in 12h. EEG showed desynchronized brain bioelectric activity. Thereafter, there was an episode of seizure and then anuria, hemodynamic instability, and loss of consciousness. Creatinine value was 5.39 mg/dL with a serious metabolic acidosis non-anion gap. We decided to start 6-hours Sustained Low Efficiency Hemo-Dia-Filtration (SLE-HDF). We assisted in the recovery of consciousness and later in the improvement of kidney function after 4 hours of treatment. TPM levels before SLE-HDF resulted in 123.1 µg/mL. At the end of treatment resulted in 30 µg/mL. To our knowledge, this is the first report of TPM involuntary intoxication in a patient affected by CKD who survived such a high TPM concentration treated with renal replacement therapy. SLE-HDF resulted in moderate elimination of TPM and acidemia resolution, continuous monitoring patient's vital parameters in relation to his hemodynamic instability, since blood flow and dialysate flow are lower than conventional hemodialysis.

Metabolic Acidosis Results in Sexually Dimorphic Response in the Heart Tissue

Metabolic acidosis (MA) is a highly prevalent disorder in a significant proportion of the population, resulting from imbalance in blood pH homeostasis. The heart, being an organ with very low regenerative capacity and high metabolic activity, is vulnerable to chronic, although low-grade, MA. To systematically characterize the effect of low-grade MA on the heart, we treated male and female mice with NH₄Cl supplementation for 2 weeks and analyzed their blood chemistry and transcriptomic signature of the heart tissue. The reduction of pH and plasma bicarbonate levels without an associated change in anion gap indicated a physiological manifestation of low-grade MA with minimal respiratory compensation. On transcriptomic analysis, we observed changes in cardiac-specific genes with significant gender-based differences due to MA. We found many genes contributing to dilated cardiomyopathy to be altered in males, more than in females, while cardiac contractility and Na/K/ATPase-Src signaling were affected in the opposite way. Our model presents a systems-level understanding of how the cardiovascular tissue is affected by MA. As low-grade MA is a common ailment with many dietary and pharmaceutical interventions, our work presents avenues to limit chronic cardiac damage and disease manifestation, as well as highlighting the sex differences in MA-induced cardiovascular damage.

The Role of Nephrologists in the Management of Methanol Poisoning

Acute methanol poisoning is a rare but serious condition that can lead to significant morbidity and mortality. Toxic metabolites produced by methanol, primarily formaldehyde, can cause high anion gap metabolic acidosis, with the severity of clinical presentation ranging from mild symptoms to multi-organ failure. Nine people died and four patients needed treatment at our university hospital following a collective intoxication caused by the consumption of homemade alcoholic beverages in the central region of Morocco. The four patients presented to the emergency department with varying clinical symptoms, such as decreased visual acuity, severe agitation, and dyspnea. The laboratory tests confirmed high anion gap metabolic acidosis and a subsequent toxicology screen revealed that they had consumed methanol-tainted alcohol. The treatment regimen involved inhibiting the formation of toxic metabolites using an antidote (ethanol or fomepizole), correcting metabolic acidosis, enhancing the elimination of toxic metabolites through prolonged hemodialysis, and administering adjunctive therapies. While two patients had favorable outcomes, the other two died from multi-organ failure. These findings highlight the importance of prompt diagnosis and treatment in cases of methanol poisoning.

Urine anion gap can differentiate respiratory alkalosis from metabolic acidosis in the absence of blood gas results

INTRODUCTION

Low plasma bicarbonate concentration due to chronic respiratory alkalosis may be misdiagnosed as metabolic acidosis and mistreated with administration of alkali therapy, particularly when arterial blood gas is not available.

METHODS

We measured urine anion gap [urine (Na⁺  + K⁺ ) - (Cl^- )], as a surrogate of renal ammonium excretion in 15 patients presenting with hyperventilation and low serum bicarbonate concentration to distinguish chronic respiratory alkalosis (CRA) from metabolic acidosis (MA) when blood gas was unavailable.

RESULTS

Hyperventilation and low serum bicarbonate concentrations were associated with urine pH above 5.5 and positive urine anion gap in all, suggesting CRA. The diagnosis was later confirmed by obtaining capillary blood gas, which showed a decrease in PCO₂ and high normal pH values.

CONCLUSION

The use of urine anion gap can help to differentiate between chronic respiratory alkalosis and metabolic acidosis, especially when arterial blood gas is not obtained.

Association of point-of-care blood variables obtained from dogs and cats during cardiopulmonary resuscitation and following return of spontaneous circulation with patient outcomes

OBJECTIVE

To investigate the association of point-of-care biochemical variables obtained during CPR or within 24 hours of return of spontaneous circulation (ROSC) with patient outcomes.

DESIGN

Retrospective study.

SETTING

University teaching hospital.

ANIMALS

Ninety-four dogs and 27 cats undergoing CPR according to the Reassessment Campaign on Veterinary Resuscitation guidelines.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Blood gas, acid-base, electrolyte, glucose, and plasma lactate values obtained during CPR or within 24 hours of ROSC were retrospectively evaluated and are described. The blood sample type and collection time with respect to CPR initiation and ROSC were recorded. Measured variables, collection times, and species were included in a multivariable logistic regression model to estimate the odds ratio (OR) and 95% confidence interval of ROSC, sustained ROSC (≥20 min), and survival to hospital discharge. Significance was set at P < 0.05. Seventy-two venous blood samples obtained during CPR and 45 first venous and arterial blood samples obtained after ROSC were included in logistic regression analysis. During CPR, PvO₂ (1.09 [1.036-1.148], P = 0.001) and venous standard base excess (SBE) (1.207 [1.094-1.331], P < 0.001) were associated with ROSC. PvO₂ (1.075 [1.028-1.124], P = 0.002), SBE (1.171 [1.013-1.353], P = 0.032), and potassium concentration (0.635 [0.426-0.946], P = 0.026) were associated with sustained ROSC. Potassium concentration (0.235 [0.083-0.667], P = 0.007) was associated with survival to hospital discharge. Following ROSC, pH (69.110 [4.393-1087], P = 0.003), potassium concentration (0.222 [0.071-0.700], P = 0.010), and chloride concentration (0.805 [0.694-0.933], P = 0.004) were associated with survival to hospital discharge.

CONCLUSIONS

Biochemical variables such as PvO₂ , SBE, and potassium concentration during CPR and pH, potassium, and chloride concentration in the postarrest period may help identify dogs and cats with lower odds for ROSC or survival to hospital discharge following CPR.

Effects of topiramate therapy on serum bicarbonate concentration in a sample of 10,279 veterans

BACKGROUND

Topiramate, which is increasingly being used to treat alcohol use disorder (AUD), is commonly associated with reduced serum bicarbonate concentrations. However, estimates of the prevalence and magnitude of this effect are from small samples and do not address whether topiramate's effects on acid-base balance differ in the presence of an AUD or by topiramate dosage.

METHODS

Veterans Health Administration electronic health record (EHR) data were used to identify patients with a minimum of 180 days of topiramate prescription for any indication and a propensity score-matched control group. We differentiated patients into two subgroups based on the presence of a diagnosis of AUD in the EHR. Baseline alcohol consumption was determined using Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) scores in the EHR. Analysis also included a three-level measure representing mean daily dosage. The topiramate-associated changes in serum bicarbonate concentration were estimated in difference-in-differences linear regression models. A serum bicarbonate concentration <17 mEq/L was considered to represent possible clinically significant metabolic acidosis.

RESULTS

The cohort comprised 4287 topiramate-treated patients and 5992 propensity score-matched controls with a mean follow-up period of 417 days. The mean topiramate-associated reductions in serum bicarbonate concentration were <2 mEq/L in the low (≤88.75), medium (>88.75 and ≤141.70), and high (>141.70) mg/day dosage tertiles, irrespective of AUD history. Concentrations <17 mEq/L occurred in 1.1% of topiramate-treated patients and 0.3% of controls and were not associated with alcohol consumption or an AUD diagnosis.

CONCLUSIONS

The excess prevalence of metabolic acidosis associated with topiramate treatment does not differ with dosage, alcohol consumption, or the presence of an AUD. Baseline and periodic serum bicarbonate concentration measurements are recommended during topiramate therapy. Patients prescribed topiramate should be educated about the symptoms of metabolic acidosis and urged to report their occurrence promptly to a healthcare provider.