Disorders of acid-base balance

Role of antioxidants and a nutrient rich diet in Alzheimer's disease

The joint attack on the body by metabolic acidosis and oxidative stress suggests that treatment in degenerative diseases, including Alzheimer's disease (AD), may require a normalizing of extracellular and intracellular pH with simultaneous supplementation of an antioxidant combination cocktail at a sufficiently high dose. Evidence is also accumulating that combinations of antioxidants may be more effective, taking advantage of synergistic effects of appropriate antioxidants as well as a nutrient-rich diet to prevent and reverse AD. This review focuses on nutritional, nutraceutical and antioxidant treatments of AD, although they can also be used in other chronic degenerative and neurodegenerative diseases.

Sociodemographic and clinical determinants of in-facility case fatality rate for 938 adult Ebola patients treated at Sierra Leone Ebola treatment center

Background

The 2013–2016 West Africa Ebola Virus Disease (EVD) outbreak recorded the highest incidence and mortality since the discovery of the virus in Zaire in 1976; with more than 28,000 probable and confirmed EVD cases and 11,000 deaths. Studies relating to previous outbreaks usually involved small sample sizes. In this study we are set to identify those sociodemographic and clinical features that predict in-facility mortality among EVD patients using a large sample size.

Methods

We analysed the anonymized medical records of 938 laboratory-confirmed EVD patients 15 years old and above who received treatment at The 34 Military Hospital and The Police Training School EVD Treatment Centers in Sierra Leone in the period June 2014 to April 2015. We used both univariable and multivariable logistic regression to determine the predictors for in-facility mortality of these patients based on their sociodemographic and clinical characteristics.

Results

The median age of the EVD cases was 33 years (interquartile range = 25 to 40 years). The majority of the EVD cases were male (59.0%) and had secondary level education (79.3%). We reported a low overall in-facility case fatality rate of 26.4%. The associations between case fatality rates and EVD patients who reported fever, abdominal pain, cough, diarrhoea, vomiting, fatigue, haemorrhage, dysphagia, conjunctival injection, dyspnea, and skin rash at the time of admission were all statistically significant (p <  0.05). Our preferred model with the age group 65 years and above alongside the following clinical symptoms; diarrhoea, vomiting, fatigue, dysphagia, conjunctival injection, dyspnea and cough produced a receiver operating characteristic (ROC) curve with an AUC (area under the curve) value of 0.93.

Conclusions

We constructed a simple model that can be optimally used alongside other rapid EVD diagnostic tools to identify EVD in-facility treatment mortality predictors based on the sociodemographic characteristics and clinical symptoms of adult EVD patients. We also reported low EVD cases among patients with secondary and tertiary education. These subpopulations of our patients who are generally informed about the signs and symptoms of EVD, alongside our treatment regimen may have been responsible for our comparatively lower case fatality rate.

Bedside ABG, electrolytes, lactate and procalcitonin in emergency pediatrics

Point of care testing, is the term commonly applied to the bedside tests performed in sick patients. Common clinical conditions encountered in pediatric emergency rooms are respiratory, gastro-intestinal, infections and cardiac. Emergencies at most of the places, especially developing countries are overburdened. Availability of tests like arterial blood gas, lactate, electrolytes and procalcitonin, bedside tests or point of care tests can help identify sick patients quickly. Abnormalities like acid-base disturbances and dyselectrolytemias can be dealt with instantly, thus improving the overall prognosis. Lactate levels in emergency give the earliest clue to cardiovascular compromise and poor tissue perfusion. Procalcitonin has recently gained significant importance as an acute phase reactant for early identification of sepsis. Decisions for initiating or withholding antibiotic therapy can also be taken based on procalcitonin levels in emergency. Bedside estimation of serum electrolytes, blood gas analysis and procalcitonin thus facilitate the clinical evaluation and management of critical patients. An extensive literature review of current status of these investigations as point of care tests is appraised here.

Central pontine and extrapontine myelinolysis owing to disequilibrium syndrome

Neurologic disorders can be seen in patients with end-stage renal failure owing to complications of hemodialysis or peritoneal dialysis. The disequilibrium syndrome can be seen, usually soon after or toward the end of dialysis. We report a patient with central pontine and extrapontine myelinolysis owing to disequilibrium syndrome. The patient had depressed consciousness, agitation, tremor, stupor and hyperactive deep tendon reflexes toward the end of the second peritoneal dialysis. A brain computed tomographic (CT) scan showed hypodense lesions in pontine and extrapontine locations without radiocontrast medium enhancement After 2 days, the patient had only minimal memory deficits. A control brain CT scan 1 week later showed a decrease of the lesions in central pontine and extrapontine locations. Central pontine and extrapontine myelinolysis should be suspected and investigated in the acute neurologic disorders of dialysis patients.

Arterial blood gas and pH analysis. Clinical approach and interpretation

Arterial blood gas and pH analysis are performed during anesthesia or critical care medicine for (1) assessment of acid-base balance, (2) assessment of pulmonary oxygenation of arterial blood, and (3) assessment of alveolar ventilation by measurement of arterial blood PCO2. Total physiologic and alveolar dead spaces are evaluated by comparing the alveolar PCO2 with the mixed expired and mixed alveolar PCO2, respectively. This article provides a clinical approach and interpretation of arterial blood gas and pH analysis.

Influence of diet on acid-base balance

It is well established that diet and certain food components have a clear impact on acid-base balance. For adults, the following factors are involved: 1) the chemical composition of foods (i.e., their content of protein, chloride, phosphorus, sodium, potassium, calcium, and magnesium), 2) the different intestinal absorption rates of the relevant nutrients, 3) the metabolic generation of sulfate from sulfur-containing amino acids, 4) the grade of dissociation of phosphorus at the physiologic pH of 7.4, and 5) the ionic valence of calcium and magnesium. All these factors allow us to estimate the potential renal acid load (PRAL) of any given food or diet. The PRAL (calculated for a 24-hour period), together with a relatively constant daily amount of urinary excreted organic acids (in healthy subjects proportional to body surface area or body weight), yields the daily net acid excretion. This article provides an overview of the current concepts of diet influences on acid-base balance and also focuses on the underlying physiologic and biochemical basis as well as on relevant clinical implications.

Growth hormone stimulation tests in chronic renal failure with metabolic acidosis

Metabolic acidosis is one of the possible causes of growth retardation in chronic renal failure (CRF). Data about the effect of metabolic acidosis on growth hormone (GH) secretion in CRF are limited. A study was carried out on eight CRF patients, hospitalized because of severe metabolic acidosis, and eight age-matched prepubertal healthy short children. Growth hormone stimulation tests were done with L-dopa and clonidine before or during acidosis therapy and after the correction of metabolic acidosis. The levels of GH were measured by radio-immunoassay. The mean of the peaks of both tests were used for each patient and statistical significance was tested by Mann-Whitney U and Wilcoxon tests. No difference was found between the GH peaks of the two groups during acidosis and after the correction of acidosis (Wilcoxon test, P > 0.05). In view of this data it was concluded that metabolic acidosis has little effect on GH stimulation tests.