Treatment of acute non-anion gap metabolic acidosis

Additional Bicarbonate Infusion Complements WHO Rehydration Therapy in Children with Acute Diarrhea and Severe Dehydration Presenting with Severe Non-anion Gap Metabolic Acidemia: An Open Label Randomized Trial

OBJECTIVES

To assess the efficacy and safety of bicarbonate infusion in children with Acute Diarrhea and Severe Dehydration (ADSD) having severe Non-Anion Gap Metabolic Acidemia (sNAGMA).

METHODS

Children (aged 1-144 mo) with ADSD and sNAGMA (pH ≤7.2 and/or serum bicarbonate ≤15 mEq/L) were enrolled in an open-label randomized design. Controls (n = 25) received WHO-recommended rehydration therapy with Ringer Lactate, while intervention group (n = 25) received additional bicarbonate deficit correction. Primary outcome was time taken to resolve metabolic acidemia (pH >7.30 and/or bicarbonate >15 mEq/L). Secondary outcome measures were adverse outcome [composite of pediatric intensive care unit (PICU) transfer and deaths], acute care area free days in 5 d (ACAFD5), hospital stay, and adverse effects.

RESULTS

Time taken to resolve metabolic acidemia was significantly lesser with intervention [median (IQR); 8 h (4, 12) vs. 12 h (8, 24); p = 0.0067]. Intervention led to acidemia resolution in significantly more children by 8 h and 16 h (17/25 vs. 9/25, p = 0.035 and 23/25 vs. 17/24, p = 0.018, respectively). Patients with fluid refractory shock needed lesser inotropes in intervention group [median Vasoactive Inotrope Score (VIS), 10.5 vs. 34]. Intervention led to significantly lesser adverse outcome (0/25 vs. 5/25, p = 0.049), and noticeably more ACAFD5 [median (IQR); 2 (1, 2) vs. 1 (1, 2); p = 0.12]. Two patients died in the control group while none in the intervention group. No adverse effect was documented.

CONCLUSIONS

Additional calculated dose of bicarbonate infusion led to significantly early resolution of metabolic acidemia, lesser utilization of critical care facilities, and lesser adverse outcome in children with ADSD and sNAGMA, compared to standard therapy, with no adverse effect.

Demystifying normal-anion-gap metabolic acidosis: pathophysiology, aetiology, evaluation and diagnosis

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

Metabolic acidemia due to saline absorption during transurethral and transcervical surgery: a report of 2 cases

BACKGROUND

The development of endoscopic systems that include bipolar electrocautery has enabled the use of normal saline irrigation in transurethral or transcervical endoscopic surgery. However, excessive saline absorption can cause hyperchloremic metabolic acidosis.

CASE PRESENTATION

Patient 1: A 76-year-old man was scheduled for transurethral resection of the prostate with saline irrigation. Approximately 140 min after the surgery, abdominal distension and cervical edema were observed. Abdominal ultrasound examination indicated a subhepatic hypoechoic lesion, which suggested extravasation of saline. Arterial blood gas analysis revealed hyperchloremic metabolic acidosis. The patient was extubated 2 h after the operation with no subsequent airway problems, and the electrolyte imbalance was gradually corrected. Patient 2: A 43-year-old woman was scheduled for transcervical resection of a uterine fibroid with saline irrigation. When the drape was removed after the operation was finished, notable upper extremity edema was observed. Arterial blood gas analysis revealed hyperchloremic metabolic acidosis. The patient's acidemia, electrolyte imbalance, and neck edema gradually resolved, and the patient was extubated 16 h after the operation without subsequent airway problems.

CONCLUSIONS

Anesthesiologists should be aware of acidemia, cardiopulmonary complications, and airway obstruction caused by excessive saline absorption after saline irrigation in endoscopic surgery.

Association of the type of metabolic acidosis and non-survival of horses with colitis

Background

Metabolic acidosis (MA) is the most common acid-base disorder reported in horses with colitis but its association with survival is yet to be determined.

Objective

Investigate the types of MA in horses with colitis to determine effects of various anions on fatality rates.

Animals and procedures

We studied 158 horses with colitis. Horses were classified into 4 groups depending on the anion contributing to MA: i) no MA, ii) lactic acidosis (LA), iii) unmeasured strong ion (USI) acidosis, and iv) hyperchloremic acidosis (HA).

Results

Sixty percent (95/158) of horses had no MA, 22% (34/158) had LA, 12% (19/158) had HA, and 6% (10/158) had USI acidosis. The fatality rate of horses without MA was 20% (20/95), whereas the rates for those with LA, USI, and HA were 53% (18/34), 30% (3/10), and 16% (3/19), respectively. Horses with LA were more likely to die or be euthanized than horses without MA (OR: 4.2, 95% CI: 1.83 to 9.72, P < 0.001) and HA (OR: 5.9, 95% CI: 1.47 to 24.4, P < 0.01).

Conclusion and clinical relevance

Lactic acidosis was the most common type of MA in horses with colitis, and it was associated with non-survival.

Dynamic changes in intestinal microbiota and metabolite composition of pre-weaned beef calves

Gut microbes and their metabolites are essential for maintaining host health and production. The intestinal microflora of pre-weaned calves gradually tends to mature with growth and development and has high plasticity, but few studies have explored the dynamic changes of intestinal microbiota and metabolites in pre-weaned beef calves. In this study, we tracked the dynamics of faecal microbiota in 13 new-born calves by 16S rRNA gene sequencing and analysed changes in faecal amino acid levels using metabolomics. Calves were divided into the relatively high average daily gain group (HA) and the relatively low average daily gain group (LA) for comparison. The results demonstrated that the alpha diversity of the faecal microbiota increased with calf growth and development. The abundance of Porphyromonadaceae bacterium DJF B175 increased in the HA group, while that of Lactobacillus reuteri decreased. The results of the LEfSe analysis showed that the microbiota of faeces of HA calves at eight weeks of age was enriched with P. bacterium DJF B175, while Escherichia coli and L. reuteri were enriched in the microbiota of faeces of LA calves. Besides, the total amino acid concentration decreased significantly in the eighth week compared with that in the first week (P < 0.05). Overall, even under the same management conditions, microorganisms and their metabolites interact to play different dynamic regulatory roles. Our results provide new insights into changes in the gut microbiota and metabolites of pre-weaned calves.

Acute Diarrhea and Severe Dehydration in Children: Does Non-anion-gap Component of Severe Metabolic Acidemia Need More Attention?

Background

Despite significant loss of bicarbonate during acute diarrhea, pediatric data are scarce with acute diarrhea/severe dehydration (ADSD) and severe non-anion-gap metabolic acidemia (sNAGMA). We planned to study their clinical profile, critical care needs, and outcome.

Patients

Children (1 month-12 years) with ADSD and sNAGMA (pH <7.2 and/or bicarbonate <15 mEq/L, and normal/mixed anion gap) admitted in Pediatric Emergency Department from January 2016 to December 2018 were enrolled. Children with pure high-anion-gap metabolic acidemia were excluded.

Methods

Medical records were reviewed retrospectively. The primary outcome was time taken to resolve acidemia. Secondary outcomes were acute care area free days in 5 days (ACAFD₅), and adverse outcome as composite of Pediatric Intensive Care Unit (PICU) admission and/or death.

Results

Out of 929 diarrhea patients admitted for intravenous therapy, 121 (13%; median age, 4 months) had ADSD and sNAGMA. Median (IQR) pH was 7.11 (7.01-7.22); 21% patients had pH <7.00. Hyperchloremia (96%) and hypernatremia (45%) were common. About 12% patients each required inotropes and ventilation, while 58% had acute kidney injury (AKI). Median (IQR) time for resolution of acidemia among survivors was 24 (12, 24) hours. Thirty-two patients had adverse outcome. Higher grades of sNAGMA were associated with shock, AKI, coma, hypernatremia, hyperkalemia, adverse outcome, and lesser ACAFD₅. Shock, ventilation, renal replacement therapy (RRT), and higher grades of sNAGMA were predictors of adverse outcome, with former two being independent predictors.

Conclusion

Severe non-anion-gap metabolic acidemia in children with ADSD is associated with organ dysfunctions, dyselectrolytemias, and lesser ACAFD5. Resolution of acidemia took unacceptably longer time. Higher grades of sNAGMA were a predictor of adverse outcomes. Trials are suggested to assess the role of additional bicarbonate therapy.

How to cite this article

Takia L, Baranwal AK, Gupta PK, Angurana SK, Jayashree M. Acute Diarrhea and Severe Dehydration in Children: Does Non-anion-gap Component of Severe Metabolic Acidemia Need More Attention? Indian J Crit Care Med 2022;26(12):1300-1307.

How to interpret arterial blood gas results

Arterial blood gas analysis is designed to measure the levels of oxygen and carbon dioxide in the blood, as well as the acid-base (pH) balance. Arterial blood gas analysis can assist healthcare professionals to evaluate respiration, circulation and metabolic processes in deteriorating patients. Arterial blood gas analysis is usually undertaken by a trained healthcare professional where patients are acutely unwell or deteriorating. REFLECTIVE ACTIVITY: 'How to' articles can help to update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of.

Ibuprofen-Associated Hypokalemia and Metabolic Acidosis: Systematic Literature Review

OBJECTIVE

Ibuprofen is a widely used nonsteroidal anti-inflammatory drug, which has been occasionally associated with hypokalemia and metabolic acidosis. The objective of this report is to analyze the literature on this issue and to address the underlying pathophysiology.

DATA SOURCES

Excerpta Medica, the National Library of Medicine, and Web of Science were searched from inception to July 16, 2021.

STUDY SELECTION AND DATA EXTRACTION

Papers reporting individually documented humans on ibuprofen with hypokalemia, acidosis, or both were retained. Data were extracted using a checklist.

DATA SYNTHESIS

For the final analysis, we evaluated 41 reports describing 50 cases (26 males and 24 females; 36 adults and 14 children) with often profound hypokalemia, acidosis, or both after ingestion of ibuprofen. Twenty-six cases were acute and 24 long term. Hypokalemia and acidosis occurred not only after ingestion of very high doses but also after ingestion of moderately high or even normal doses of ibuprofen. Laboratory values consistent with an excessive urinary potassium excretion or an altered urinary acidification were often disclosed in most cases. Discontinuation of ibuprofen resulted in a resolution of hypokalemia and acidosis within days in 47 cases. The course was lethal in 3 cases.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review highlights potentially fatal side effects of ibuprofen and can help doctors who are confronted with such a situation.

CONCLUSIONS

These data highlight the potential of ibuprofen to occasionally induce hypokalemia and acidosis of renal origin. Discontinuation of ibuprofen results in a resolution within days.

A Claims Database Analysis of Dose-Dependency of Metformin and Incidence of Lactic Acidosis in Japanese Patients with Type 2 Diabetes

INTRODUCTION

Patients with type 2 diabetes (T2D) in Japan are prescribed a lower dose of metformin that their counterparts in Western countries due to concerns for the risk of lactic acidosis incidence. Here we report our study on the association between high-dose metformin administration and the incidence of lactic acidosis in Japanese patients with T2D.

METHODS

A Japanese claims database (April 2008-November 2018) was analyzed. Factors associated with the incidence of lactic acidosis were first identified from the database records by conducting a case-control study, and these were then used as confounding factors in subsequent analyses. The association between high-dose metformin administration (≥ 1000 mg/day) and the incidence of lactic acidosis was compared with that between low-dose metformin (< 1000 mg/day) or no metformin administration and lactic acidosis incidence by using the following approaches: a logistic regression analysis hypothesizing that metformin-associated lactic acidosis is short term; a time-dependent proportional hazard model hypothesizing that the influence of metformin is cumulative; and a case-control study in which lactic acidosis incidence was the case and metformin administration within 3 months prior to the incidence of lactic acidosis (or corresponding date for the control) was the exposure.

RESULTS

Prescriptions for biguanide and vitamin B complex and volume depletion were identified as factors associated with the incidence of lactic acidosis. The incidence rate was higher in patients prescribed metformin than in those not receiving metformin; however, it was not higher in those prescribed high-dose metformin compared to those prescribed low-dose metformin. The estimated regression coefficient for high-dose metformin administration was 0.816 (p < 0.001); this was not higher than those for low-dose metformin (1.047), vitamin B complex (2.725) and volume depletion (3.301). The time-dependent proportional hazard analysis did not indicate any effect of metformin prescription.

CONCLUSION

The results suggest an association between metformin administration and the incidence of lactic acidosis, but an increase in the incidence rate of lactic acidosis was not observed in those patients receiving high-dose metformin compared to those receiving low-dose metformin.

Acute Metabolic Emergencies in Diabetes: DKA, HHS and EDKA

Emergency admissions due to acute metabolic crisis in patients with diabetes remain some of the most common and challenging conditions. DKA (Diabetic Ketoacidosis), HHS (Hyperglycaemic Hyperosmolar State) and recently focused EDKA (Euglycaemic Diabetic Ketoacidosis) are life-threatening different entities. DKA and HHS have distinctly different pathophysiology but basic management protocols are the same. EDKA is just like DKA but without hyperglycaemia. T1D, particularly children are vulnerable to DKA and T2D, particularly elderly with comorbidities are vulnerable to HHS. But these are not always the rule, these acute conditions are often occur in different age groups with diabetes. It is essential to have a coordinated care from the multidisciplinary team to ensure the timely delivery of right treatment. DKA and HHS, in many instances can present as a mixed entity as well. Mortality rate is higher for HHS than DKA but incidences of DKA are much higher than HHS. The prevalence of HHS in children and young adults are increasing due to exponential growth of obesity and increasing T2D cases in this age group. Following introduction of SGLT2i (Sodium-GLucose co-Transporter-2 inhibitor) for T2D and off-label use in T1D, some incidences of EDKA has been reported. Healthcare professionals should be more vigilant during acute illness in diabetes patients on SGLT2i without hyperglycaemia to rule out EDKA. Middle aged, mildly obese and antibody negative patients who apparently resemble as T2D without any precipitating causes sometime end up with DKA which is classified as KPD (Ketosis-prone diabetes). Many cases can be prevented by following 'Sick day rules'. Better access to medical care, structured diabetes education to patients and caregivers are key measures to prevent acute metabolic crisis.

Longitudinal evaluation of fecal microbiota transplantation for ameliorating calf diarrhea and improving growth performance

Calf diarrhea is associated with enteric infections, and also provokes the overuse of antibiotics. Therefore, proper treatment of diarrhea represents a therapeutic challenge in livestock production and public health concerns. Here, we describe the ability of a fecal microbiota transplantation (FMT), to ameliorate diarrhea and restore gut microbial composition in 57 growing calves. We conduct multi-omics analysis of 450 longitudinally collected fecal samples and find that FMT-induced alterations in the gut microbiota (an increase in the family Porphyromonadaceae) and metabolomic profile (a reduction in fecal amino acid concentration) strongly correlate with the remission of diarrhea. During the continuous follow-up study over 24 months, we find that FMT improves the growth performance of the cattle. This first FMT trial in ruminants suggest that FMT is capable of ameliorating diarrhea in pre-weaning calves with alterations in their gut microbiota, and that FMT may have a potential role in the improvement of growth performance.

Etiology and Management of Acute Metabolic Acidosis: An Update

BACKGROUND

The etiology of acute metabolic acidosis (aMA) is heterogeneous, and the consequences are potentially life-threatening. The aim of this article was to summarize the causes and management of aMA from a clinician's perspective.

SUMMARY

We performed a systematic search on PubMed, applying the following search terms: "acute metabolic acidosis," "lactic acidosis," "metformin" AND "acidosis," "unbalanced solutions" AND "acidosis," "bicarbonate" AND "acidosis" AND "outcome," "acute metabolic acidosis" AND "management," and "acute metabolic acidosis" AND "renal replacement therapy (RRT)/dialysis." The literature search did not consider diabetic ketoacidosis at all. Lactic acidosis evolves from various conditions, either with or without systemic hypoxia. The incidence of metformin-associated aMA is actually quite low. Unbalanced electrolyte preparations can induce hyperchloremic aMA. The latter potentially worsens kidney-related outcome parameters. Nevertheless, prospective and controlled data are missing at the moment. Recently, bicarbonate has been shown to improve clinically relevant endpoints in the critically ill, even if higher pH values (>7.3) are targeted. New therapeutics for aMA control are under development, since bicarbonate treatment can induce serious side effects. Key Messages: aMA is a frequent and potentially life-threatening complication of various conditions. Lactic acidosis might occur even in the absence of systemic hypoxia. The incidence of metformin-associated aMA is comparably low. Unbalanced electrolyte solutions induce hyperchloremic aMA, which most likely worsens the renal prognosis of critically ill patients. Bicarbonate, although potentially deleterious due to increased carbon dioxide production with subsequent intracellular acidosis, improves kidney-related endpoints in the critically ill.

Euglycaemic diabetic ketoacidosis as a complication of SGLT-2 inhibitors: epidemiology, pathophysiology, and treatment

INTRODUCTION

Sodium-glucose co-transporters 2 (SGLT-2) inhibitors are a relatively novel class of oral medications for the treatment of Type 2 Diabetes Mellitus, which lower plasma glucose by inhibiting glucose reabsorption in the proximal renal tubule. Apart from their hypoglycemic action, recent data suggest these agents have additional major cardioprotective and nephroprotective properties.

AREAS COVERED

This review summarizes the existing data on epidemiology, pathophysiology, and treatment of euglycaemic ketoacidosis (euDKA) as a complication of SGLT-2 inhibitor use.

EXPERT OPINION

Although SGLT-2 inhibitors have a relatively good adverse event profile, they have been associated with the serious and potentially life-threatening metabolic complication of euDKA. Data from major outcome trials suggest that the rate of DKA is quite low. However, the rate of DKA could be generally underestimated in clinical trials due to the atypical presentation of ketoacidosis, and even more so in real-life conditions. Management of this serious metabolic complication requires a proper understanding of its pathophysiology as well as increased awareness and early recognition of the potential risk factors involved. Following this, the institution of an array of simple supportive measures, could safely restore normal acid-base balance in most patients.

Managing Chloride and Bicarbonate in the Prevention and Treatment of Acute Kidney Injury

Intravenous crystalloid therapy is one of the most ubiquitous aspects of hospital and critical care medicine. In recent years, there has been increasing focus on the electrolyte composition, and particularly chloride content, of crystalloid solutions. This has led to increasing clinical adoption of balanced solutions, containing substrates for bicarbonate generation and consequently a lower chloride content, in place of 0.9% saline. In this article we review the physiochemical rationale for avoidance of 0.9% saline and the effects of hyperchloremic acidosis on renal physiology. Finally, we review the current evidence and rationale for use of balanced solutions greater than 0.9% saline in acutely ill patients in a variety of clinical settings, as well as considering the role for sodium bicarbonate in preventing or correcting metabolic acidosis. In conclusion, there is a strong physiological rationale for avoidance of iatrogenic hyperchloremic acidosis from 0.9% saline administration in acutely unwell patients and an association with adverse renal outcomes in several studies. However, evidence from large definitive multicenter randomized trials is not yet available to establish the dose-relationship between 0.9% saline administration and potential harm and inform us if some 0.9% saline use is acceptable or if any exposure confers harm.

High-anion gap hyperchloremic acidosis mimicking diabetic ketoacidosis on initial presentation - Case report

INTRODUCTION

Diabetic ketoacidosis (DKA) often becomes the primary focus and in turn masks a similar serious condition like hyperchloremic metabolic acidosis.

CASE REPORT

A 20 years old female with type 1 diabetes mellitus presented to the emergency department (ED) with signs and symptoms corresponding to DKA. Initial pH, HCO_3, Na and Cl concentrations were 6.83, 3.6 mmol/l, 143 mmol/l and 122 mmol/l respectively; anion gap 17.4 mmol/l and absent urinary ketones. DKA regime showed no improvement in the measured parameters nor the patient. The diagnosis changed to hyperchloremic high-anion gap acidosis and treatment modifications were made by adding sodium bicarbonate infusion. There was significant improvement in the clinical status of the patient and the calculated parameters.

DISCUSSION

Hyperchloremic acidosis is associated with a non-anion gap, decrease in plasma bicarbonate and increase in plasma chloride. Rarely, as with this case, it may present with a high-anion gap. The use of bicarbonate therapy has shown improvement in cases of non-anion gap acidosis however there is very little data to support its role in high-anion gap hyperchloremic metabolic acidosis.

Bicarbonate use and mortality outcome among critically ill patients with metabolic acidosis: A meta analysis

BACKGROUND

The use of sodium bicarbonate in the treatment of metabolic acidosis in critically ill subjects has long been a subject of debate. Despite empiric use in the setting of severe acidemia in critically ill patients, there is little data looking into the role of sodium bicarbonate in the treatment of severe metabolic acidosis in the intensive care unit (ICU) setting.

METHODS

We conducted a comprehensive search of Pubmed and Cochrane Central Register of Controlled Trials addressing bicarbonate use in the metabolic acidosis in the intensive care unit (ICU) setting. We examined mortality as end point. Pooled odds ratios (OR) and their 95% confidence intervals (CI) were calculated for all outcomes using a random-effect model.

RESULTS

The final search yielded 202 articles of which all were screened individually. A total of 11 studies were identified but 6 studies were excluded due to irrelevance in mortality outcome and methodology. Analysis was done separately for observational studies and randomized controlled trials. The pooled OR [95% CI] for mortality with bicarbonate use in the observational studies was 1.5 [0.62-3.67] with heterogeneity of 67%, while pooled OR for mortality in the randomized trials was 0.72 [0.49-1.05] (figure 2). In combining all studies, the pooled odds ratio was 0.93 95% [0.69-1.25] but with heterogeneity of 63%. After sensitivity analysis with removing the study done by Kim et al. 2013, heterogeneity was 0% with OR 0.8 [0.59-1.10].

CONCLUSION

There is no significant difference in mortality in the use of bicarbonate among critically ill patients with high anion gap metabolic acidosis predominantly driven by lactic acidosis.

Removal of urea by electro-oxidation in a miniature dialysis device: a study in awake goats

The key to success in developing a wearable dialysis device is a technique to safely and efficiently regenerate and reuse a small volume of dialysate in a closed-loop system. In a hemodialysis model in goats, we explored whether urea removal by electro-oxidation (EO) could be effectively and safely applied in vivo. A miniature dialysis device was built, containing 1 or 2 "EO units," each with 10 graphite electrodes, with a cumulative electrode surface of 585 cm2 per unit. The units also contained poly(styrene-divinylbenzene) sulfonate beads, FeOOH beads, and activated carbon for respective potassium, phosphate, and chlorine removal. Urea, potassium, and phosphate were infused to create "uremic" conditions. Urea removal was dependent on total electrode surface area [removal of 8 mmol/h (SD 1) and 16 mmol/h (SD 2) and clearance of 12 ml/min (SD 1) and 20 ml/min (SD 3) with 1 and 2 EO units, respectively] and plasma urea concentration but not on flow rate. Extrapolating urea removal with 2 EO units to 24 h would suffice to remove daily urea production, but for intermittent dialysis, additional units would be required. EO had practically no effects on potassium and phosphate removal or electrolyte balance. However, slight ammonium releasewas observed, and some chlorine release at higher dialysate flow rates. Minor effects on acid-base balance were observed, possibly partly due to infusion of chloride. Mild hemolysis occurred, which seemed related to urea infusion. In conclusion, clinically relevant urea removal was achieved in vivo by electro-oxidation. Efficacy and safety testing in a large-animal model with uremia is now indicated.

Pyruvate is a prospective alkalizer to correct hypoxic lactic acidosis

Type A lactic acidosis resulted from hypoxic mitochondrial dysfunction is an independent predictor of mortality for critically ill patients. However, current therapeutic agents are still in shortage and can even be harmful. This paper reviewed data regarding lactic acidosis treatment and recommended that pyruvate might be a potential alkalizer to correct type A lactic acidosis in future clinical practice. Pyruvate is a key energy metabolic substrate and a pyruvate dehydrogenase (PDH) activator with several unique beneficial biological properties, including anti-oxidant and anti-inflammatory effects and the ability to activate the hypoxia-inducible factor-1 (HIF-1α) - erythropoietin (EPO) signal pathway. Pyruvate preserves glucose metabolism and cellular energetics better than bicarbonate, lactate, acetate and malate in the efficient correction of hypoxic lactic acidosis and shows few side effects. Therefore, application of pyruvate may be promising and safe as a novel therapeutic strategy in hypoxic lactic acidosis correction accompanied with multi-organ protection in critical care patients.

Effect of Intravenously Administered Crystalloid Solutions on Acid-Base Balance in Domestic Animals

Intravenous fluid therapy can alter plasma acid-base balance. The Stewart approach to acid-base balance is uniquely suited to identify and quantify the effects of the cationic and anionic constituents of crystalloid solutions on plasma pH. The plasma strong ion difference (SID) and weak acid concentrations are similar to those of the administered fluid, more so at higher administration rates and with larger volumes. A crystalloid's in vivo effects on plasma pH are described by 3 general rules: SID > [HCO3-] increases plasma pH (alkalosis); SID < [HCO3-] decreases plasma pH (alkalosis); and SID = [HCO3-] yields no change in plasma pH. The in vitro pH of commercially prepared crystalloid solutions has little to no effect on plasma pH because of their low titratable acidity. Appreciation of IV fluid composition and an understanding of basic physicochemical principles provide therapeutically valuable insights about how and why fluid therapy can produce and correct alterations of plasma acid-base equilibrium. The ideal balanced crystalloid should (1) contain species-specific concentrations of key electrolytes (Na+ , Cl- , K+ , Ca++ , Mg++ ), particularly Na+ and Cl- ; (2) maintain or normalize acid-base balance (provide an appropriate SID); and (3) be isosmotic and isotonic (not induce inappropriate fluid shifts) with normal plasma.

Emergency anesthesia for evacuating a traumatic acute subdural hemorrhage in a child overdosed with hypertonic saline

A previously healthy 1-year-old child with a traumatic acute subdural hemorrhage received 10 times higher dose of hypertonic saline inadvertently immediately before surgery. This case report describes deviations in fluid management needed to alleviate salt toxicity and its adverse effects during surgery under anesthesia perioperatively. The child made an uneventful recovery with no evident residual damage at follow-up.

Non-Anion Gap Metabolic Acidosis: A Clinical Approach to Evaluation

Acid-base disturbances can result from kidney or nonkidney disorders. We present a case of high-volume ileostomy output causing large bicarbonate losses and resulting in a non-anion gap metabolic acidosis. Non-anion gap metabolic acidosis can present as a form of either acute or chronic metabolic acidosis. A complete clinical history and physical examination are critical initial steps to begin the evaluation process, followed by measuring serum electrolytes with a focus on potassium level, blood gas, urine pH, and either direct or indirect urine ammonium concentration. The present case was selected to highlight the differential diagnosis of a non-anion gap metabolic acidosis and illustrate a systematic approach to this problem.

Infectious Diarrhea: Norovirus and Clostridium difficile in Older Adults

Norovirus infection usually results in acute gastroenteritis, often with incapacitating nausea, vomiting, and diarrhea. It is highly contagious and resistant to eradication with alcohol-based hand sanitizer. Appropriate preventative and infection control measures can mitigate the morbidity and mortality associated with norovirus infection. Clostridium difficile infection is the leading cause of health care-associated diarrhea in the United States. Antibiotic use is by far the most common risk factor for C difficile colonization and infection. Appropriate preventive measures and judicious use of antibiotics can help mitigate the morbidity and mortality associated with C difficile infection.

Metabolic acidosis during parenteral nutrition: Pathophysiological mechanisms

Total parenteral nutrition (TPN) is associated with metabolic complications including metabolic acidosis (MA), one of the main disorders of acid-base balance. The main causes involved in the appearance of MA during TPN administration are the metabolism of cationic amino acids and amino acids containing sulfuric acid (exogenous addition), the titratable acidity of the infused parenteral solution, the addition of acidificant agents (hydrochloric acid, acetic acid), thiamine deficiency, disruption of carbohydrate and lipid metabolic pathways and D-fructose administration. Moreover, hypophosphatemia that appears during TPN therapy contributes significantly to the maintenance of MA. This review describes in a comprehensive way the pathophysiological mechanisms involved in the appearance of MA induced by intravenous administration of TPN products most commonly used in critically ill-patients.