Metabolic Acidosis in the Surgical Intensive Care Unit: Risk Factors, Clinical Correlates and Outcome. Findings from a High Dependency Heart and Vascular Surgical Center in Nigeria

Background: Metabolic acidosis (MA) is a common finding on the surgical ward, more so in the intensive care unit. Diseases affecting the major organ systems of the body and higher grades of surgery are common risk factors for MA. It is associated with poor treatment outcome. Aim: To determine the risk factors and clinical correlates of metabolic acidosis and assess its relationship with treatment outcome. Methodology: A retrospective study at the “Tristate Heart and vascular Center” in Ilishan-Remo South west Nigeria, on patients that had cardiac and vascular surgeries from January 2015 to December 2019. Three hundred and forty two participants took part in the study. The demographic, clinical and laboratory findings were entered. Statistical analysis was with Student’s t-test and Chi square. Results: Two hundred and six males and 136 females were studied. The incidences of metabolic acidosis prior to induction, on post-operative day one (POD1) and on POD28 were 20.7%, 39.8% and 14.1% respectively. Nine (2.6%) participants died during admission, of this, 6 (66.7%) had MA at presentation but all (100%) had MA on POD1. The Risk factors for MA were advanced age, comorbidities, open heart surgery, elevated systolic blood pressure and low eGFR. Metabolic acidosis was a risk factor for prolonged hospital stay, perioperative death and declining kidney function which was commoner among participants with preexisting kidney dysfunction. Conclusion: The incidence of metabolic acidosis was 20.7% at induction of anesthesia, rose to 39.8% on POD1 and by POD28, it has significantly reduced to 14.1%. While advancing age and comorbidities were risk factors for MA, the occurrence of MA increased the risk of declining kidney function, prolonged hospital stay and death.

Metabolic Acidosis in Critically Ill Cirrhotic Patients with Acute Kidney Injury

Background and Aims:The metabolic acid-base disorders have a high incidence of acute kidney injury(AKI)in critically ill cirrhotic patients(CICPs).The aims of our study were to ascertain the composition of metabolic acidosis of CICPs with AKI and explore its relationship with hospital mortality.Methods:Three-hundred and eighty consecutive CICPs with AKI were eligible for the cohort study.Demographic,clinical and laboratory parameters were recorded and arterial acid-base state was analyzed by the Stewart and Gilfix methodology.Results:Net metabolic acidosis,lactic acidosis,acidosis owing to unmeasured anions,acidemia,and dilutional acidosis were less frequent in the non-survival group compared to the survival group of CICPs.The presence of acidemia,acidosis owing to unmeasured anions,and lactic acidosis were independently associated with increased risk of intensive care unit 30-day mortality,with hazard ratios of 2.11(95%confidence interval(CI):1.43–3.12),3.38(95%CI:2.36–4.84),and 2.16(95%CI:1.47–3.35),respectively.After full adjustment for confounders,the relationship between acidosis owing to unmeasured anions with hospital mortality was still significant,with hazard ratio of 2.29(95%CI:1.22–4.30).Furthermore,arterial lactate concentration in combination with chronic liver failure-sequential organ failure assessment and BEUMA had the strongest ability to differentiate 30-day mortality(area under the receiver operating characteristic curve:0.79,95%CI:0.74–0.83).

Renal calcification in children with renal tubular acidosis:What a paediatrician should know

Renal tubular acidosis(RTA)can lead to renal calcification in children,which can cause various complications and impair renal function.This review provides pediatricians with a comprehensive understanding of the relationship between RTA and renal calcification,highlighting essential aspects for clinical manage-ment.The article analyzed relevant studies to explore the prevalence,risk factors,underlying mechanisms,and clinical implications of renal calcification in children with RTA.Results show that distal RTA(type 1)is particularly associated with nephrocalcinosis,which presents a higher risk of renal calcification.However,there are limitations to the existing literature,including a small number of studies,heterogeneity in methodologies,and potential publication bias.Longitudinal data and control groups are also lacking,which limits our understanding of longterm outcomes and optimal management strategies for children with RTA and renal calcification.Pediatricians play a crucial role in the early diagnosis and management of RTA to mitigate the risk of renal calcification and associated complications.In addition,alkaline therapy remains a cornerstone in the treatment of RTA,aimed at correcting the acid-base imbalance and reducing the formation of kidney stones.Therefore,early diagnosis and appropriate therapeutic interventions are paramount in preventing and managing renal calcification to preserve renal function and improve long-term outcomes for affected children.Further research with larger sample sizes and rigorous methodologies is needed to optimize the clinical approach to renal calcification in the context of RTA in the pediatric population.

Methylmalonic Acidemia: An Unusual Cause of Chronic Renal Disease in Adults

Background: Methylmalonic aciduria (MMA) is a genetic disorder of aminoacid metabolism, due to mutations in methylmalonyl-CoA mutase, which leads to the accumulation of methylmalonic acid in body fluids. Patients typically present at the age of 1 month to 1 year with dehydration, renal impairment as well as neurologic manifestations viz. seizure, encephalopathy, strokes and disease in the globus pallidi. The case: a 26-year-old man presented with severe acute on top of chronic renal disease with serum creatinine at 590 umol/L and bilateral 8 cm kidneys with thin and echogenic cortex. He had: (a) hypernatremic dehydration, metabolic acidosis and high ammonia level with (b) a history of multiple similar attacks since the age of 8 months. Diagnosis of MMA was confirmed by high serum and urine enzymatic levels as well as genetic testing. His initial management included support with replacements of fluids, electrolytes, and bicarbonates as well as intravenous dextrose, vitamin B12 and broad-spectrum antibiotic (Meropenem) for his chest infection. Subsequently, he received 1) CARBAGLU (carglumic acid) for 7 days to lower his ammonia level to Conclusion: Untreated homozygous MMA variants, can achieve adulthood with significant renal disease yet their morbidity and mortality can be ameliorated with diet and specific therapy.

Euglycemic diabetic ketoacidosis:A missed diagnosis

Euglycemic diabetic ketoacidosis(DKA)is an acute life-threatening metabolic emergency characterized by ketoacidosis and relatively lower blood glucose(less than 11 mmol/L).The absence of hyperglycemia is a conundrum for physicians in the emergency department and intensive care units;it may delay diagnosis and treatment causing worse outcomes.Euglycemic DKA is an uncommon diagnosis but can occur in patients with type 1 or type 2 diabetes mellitus.With the addition of sodium/glucose cotransporter-2 inhibitors in diabetes mellitus management,euglycemic DKA incidence has increased.The other causes of euglycemic DKA include pregnancy,fasting,bariatric surgery,gastroparesis,insulin pump failure,cocaine intoxication,chronic liver disease and glycogen storage disease.The pathophysiology of euglycemic DKA involves a relative or absolute carbohydrate deficit,milder degree of insulin deficiency or resistance and increased glucagon/insulin ratio.Euglycemic DKA is a diagnosis of exclusion and should be considered in the differential diagnosis of a sick patient with a history of diabetes mellitus despite lower blood glucose or absent urine ketones.The diagnostic workup includes arterial blood gas for metabolic acidosis,serum ketones and exclusion of other causes of high anion gap metabolic acidosis.Euglycemic DKA treatment is on the same principles as for DKA with correction of dehydration,electrolytes deficit and insulin replacement.The dextrosecontaining fluids should accompany intravenous insulin to correct metabolic acidosis,ketonemia and to avoid hypoglycemia.

Overlap of diabetic ketoacidosis and hyperosmolar hyperglycemic state

Diabetic ketoacidosis(DKA)and hyperosmolar hyperglycemia state(HHS)are two life-threatening metabolic complications of diabetes that significantly increase mortality and morbidity.Despite major advances,reaching a uniform consensus regarding the diagnostic criteria and treatment of both conditions has been challenging.A significant overlap between these two extremes of the hyperglycemic crisis spectrum poses an additional hurdle.It has well been noted that a complete biochemical and clinical patient evaluation with timely diagnosis and treatment is vital for symptom resolution.Worldwide,there is a lack of large-scale studies that help define how hyperglycemic crises should be managed.This article will provide a comprehensive review of the pathophysiology,diagnosis,and management of DKA-HHS overlap.

Liver or kidney:Who has the oar in the gluconeogenesis boat and when?

Gluconeogenesis is an endogenous process of glucose production from noncarbohydrate carbon substrates.Both the liver and kidneys express the key enzymes necessary for endogenous glucose production and its export into circulation.We would be remiss to add that more recently gluconeogenesis has been described in the small intestine,especially under high-protein,lowcarbohydrate diets.The contribution of the liver glucose release,the net glucose flux,towards systemic glucose is already well known.The liver is,in most instances,the primary bulk contributor due to the sheer size of the organ(on average,over 1 kg).The contribution of the kidney(at just over 100 g each)to endogenous glucose production is often under-appreciated,especially on a weight basis.Glucose is released from the liver through the process of glycogenolysis and gluconeogenesis.Renal glucose release is almost exclusively due to gluconeogenesis,which occurs in only a fraction of the cells in that organ(proximal tubule cells).Thus,the efficiency of glucose production from other carbon sources may be superior in the kidney relative to the liver or at least on the level.In both these tissues,gluconeogenesis regulation is under tight hormonal control and depends on the availability of substrates.Liver and renal gluconeogenesis are differentially regulated under various pathological conditions.The impact of one source vs the other changes,based on post-prandial state,acid-base balance,hormonal status,and other less understood factors.Which organ has the oar(is more influential)in driving systemic glucose homeostasis is still inconclusive and likely changes with the daily rhythms of life.We reviewed the literature on the differences in gluconeogenesis regulation between the kidneys and the liver to gain an insight into who drives the systemic glucose levels under various physiological and pathological conditions.

Can Peripheral Venous Gases Replace Arterial Gases in a Patient with Chronic Kidney Disease?

Introduction: Metabolic acidosis (MA) is a frequent alteration in chronic kidney disease (CKD) that is associated with numerous complications, which is why its correction is recommended. Oral sodium bicarbonate is currently the treatment of choice. Objective: The objective is to determine if venous bicarbonate is equal to arterial bicarbonate in the follow-up of a patient with chronic kidney disease. Materials Methods: Single-center Cross-sectional studies in a cohort of adult patients with stage 4 - 5 CKD. Samples were taken between January 2022 and January 2023, in a Clinic in the city of Ibague/ Colombia obtained from the radial artery. The inclusion criteria were: not being treated with alkaline at the time of inclusion. Results: A total of 71 patients were included, 73.2% male (52) and 26.8% female (19), with different stages: stage 3 with 5.6% (4), stage 4 with 60.6% (43), stage 5 with 33.8% (23). 66.2% were diabetic, 88.7% had arterial hypertension, and 15.5% of the patients presented hematoma as a complication and pain associated with arterial puncture. The result of mean venous bicarbonate was 18.8 with a standard deviation of 2.3, arterial bicarbonate a mean of 19.4 with a standard deviation of 2.1 with a value of P 0.46, venous pH with a mean of 7.37 with a standard deviation of 0.48 and a mean arterial pH of 7.38 with a standard deviation of 0.48 with a P value of 0.01. Values of venous bicarbonate compared to arterial bicarbonate showed no statistically significant difference in patients with chronic kidney disease, but there were more complications such as hematoma and pain in patients in the arterial puncture cohort, because of this result venous bicarbonate corresponds to arterial bicarbonate, but has less risk of complications associated with the procedure. Conclusion: Metabolic acidosis is a frequent alteration in advanced chronic kidney disease, these results showed that the values of arterial and venous bicarbonate have no statistically significant differences, but there is a greater risk of complications with arterial blood gases, due to this, venous bicarbonate could be a useful tool for patients with chronic kidney disease.

Osmol gap method for the detection of diethylene glycol in human serum

BACKGROUND： Measurement of the osmol gap （OG） is a technique that is used frequently in toxic alcohol poisonings （ethylene glycol （EG） and methanol） as a rapid means to estimate exposure, and can be performed in virtually all hospital laboratories. The value of the OG has not been previously evaluated for diethylene glycol （DEG） exposures. The primary objective of this study was to evaluate the utility of the OG in estimating DEG serum concentrations using the most common formula that is currently used for estimating methanol, ethanol, and ethylene glycol concentrations.METHODS： This was a controlled laboratory investigation using serum samples individually spiked with a known quantity of toxic alcohol compared to no toxic alcohol. Test samples were spiked with ethanol, DEG, EG, and methanol. Serum chemistries and osmolality and osmolarity were determined, and the OG was determined for each specimen.RESULTS： The percent error of estimating DEG concentrations of 26.3% was similar to the mean percent error for estimating other alcohol concentrations, 30.5%±5.6% （P〉0.05, 95% confidence interval 16.7%-44.3%）.CONCLUSION： The severity of metabolic effects associated with DEG and the need to appropriately determine rescue treatments mandate early detection of significant exposures for effective triage and patient management. Our results indicate that the percent error of the osmol gap method for estimating DEG concentration is similar to that of other toxic alcohols; this simple technique could be a valuable clinical tool, since quantitative DEG analysis is rarely available.

Carbon dioxide:Global warning for nephrologists

The large prevalence of respiratory acid-base disordersoverlapping metabolic acidosis in hemodialysis popu-lation should prompt nephrologists to deal with the partial pressure of carbon dioxide （pCO2） complying with the reduced bicarbonate concentration. What the most suitable formula to compute pCO2 is reviewed. Then, the neglected issue of CO2 content in the dialysis fluid is under the spotlight. In fact, a considerable amount of CO2 comes to patients’ bloodstream every hemodialysis treatment and “acidosis by dialysate” may occur if lungs do not properly clear away this burden of CO2. Moreover, vascular access recirculation may be easy diagnosed by detecting CO2 in the arterial line of extracorporeal circuit if CO2-enriched blood from the flter reenters arterial needle.

Lessons from a methanol poisoning outbreak in Egypt: Six case reports

BACKGROUND Mass methanol poisonings are challenging,especially in regions with no preparedness,management guidelines and available antidotes.CASE SUMMARY Six Ukrainian patients were referred to our emergency department in Cairo,Egypt several hours after drinking an alcoholic beverage made of 70%-ethanol disinfectant bought from a local pharmacy.All patients presented with severe metabolic acidosis and visual impairments.Two were comatose.Management was based on the clinical features and chemistry tests due to deficient resources for methanol leveling.No antidote was administered due to fomepizole unavailability and the difficulties expected to obtain ethanol and safely administer it without concentration monitoring.One patient died from multiorgan failure,another developed blindness and the four other patients rapidly improved.CONCLUSION This methanol poisoning outbreak strongly highlights the lack of safety from hazardous pharmaceuticals sold in pharmacies and limitations due to the lack of diagnostic testing,antidote availability and staff training in countries with limited-resources such as Egypt.

Distal renal tubular acidosis:genetic causes and management

Background Distal renal tubular acidosis(dRTA)is a kidney tubulopathy that causes a state of normal anion gap metabolic acidosis due to impairment of urine acidification.This review aims to summarize the etiology,pathophysiology,clinical findings,diagnosis and therapeutic approach of dRTA,with emphasis on genetic causes of dRTA.Data sources Literature reviews and original research articles from databases,including PubMed and Google Scholar.Manual searching was performed to identify additional studies about dRTA.Results dRTA is characterized as the dysfunction of the distal urinary acidification,leading to metabolic acidosis.In pediatric patients,the most frequent etiology of dRTA is the genetic alteration of genes responsible for the codification of distal tubule channels,whereas,in adult patients,dRTA is more commonly secondary to autoimmune diseases,use of medications and uropathies.Patients with dRTA exhibit failure to thrive and important laboratory alterations,which are used to define the diagnosis.The oral alkali and potassium supplementation can correct the biochemical defects,improve clinical manifestations and avoid nephrolithiasis and nephrocalcinosis.Conclusions dRTA is a multifactorial disease leading to several clinical manifestations.Clinical and laboratory alterations can be corrected by alkali replacement therapy.