Abnormalities In Acid-base Balance Research Articles

Adrenal crisis as a life-threatening condition

Adrenal crisis is a medical emergency, which requires quick, accurate diagnosis and the implementation of adequate treatment. It usually occurs in patients taking glucocorticoid therapy due to chronic adrenal insufficiency in conditions that demand increased glucocorticoids, such as infection, trauma, surgery, myocardial infarction, stroke, exercise or acute stress. The disease follows a course of shock that does not respond to catecholamines. Prodromal symptoms include decreased appetite, nausea, vomiting, abdominal pain, joint or muscle pain, and fatigue. This is followed by fluctuating consciousness, as well as reduced blood pressure and tachycardia, which are symptoms of shock. These symptoms result from the following metabolic disorders: hyponatremia, hyperkalaemia, hypoglycaemia and mild hypercalcemia. Due to the absence of characteristic symptoms in adrenal crisis, the basis for correct diagnosis in a prehospital setting is a carefully collected medical history, followed by a detailed physical examination that should pay particular attention to discoloration of the skin (so-called melasma suprarenale) that is not exposed to light: the hands (especially creases), elbows, areolae, scars and buccal mucosa, which is one of the symptoms of primary adrenal insufficiency (Addison’s disease). The therapeutic approach consists in the administration of intravenous hydrocortisone (to moderate cortisol deficiency), modifying fluid and electrolyte imbalances and abnormalities of acid-base balance, and treating the disease that has led to decompensation of the patient’s clinical condition, which in many cases is an infection. Adrenal crisis left untreated leads to patient death.

Central Sleep Apnea – a Rare Cause for Acute Respiratory Insufficiency in Children. Case Report

Central sleep apnea is characterized by frequent cessation of breathing during sleep, resulting in repetitive episodes of insufficient ventilation and abnormalities of acid-base balance. It may be primary or secondary, and it is uncommon in children, with limited data for this population. We present here the case of a five-year-old girl, known to have thoracolumbar myelomeningocele (for which she underwent a surgical procedure in infancy), secondary hydrocephalus (with a ventriculoperitoneal shunt) and flaccid paralysis, who was admitted in our hospital with prolonged fever syndrome, productive cough, severe dyspnea and perioral cyanosis. Following physical examination, laboratory investigations and thoracic radiography, we established the diagnosis of aspiration pneumonia with acute respiratory failure. Medical treatment with multiple systemic antibiotics, antifungal agents, systemic and inhaled bronchodilator, oxygen therapy and respiratory nursing were initiated, with favorable evolution. During the entire hospitalization, the patient showed nocturnal respiratory rhythm disorders, with sleep apnea crisis of approximately 20 seconds and desaturation, followed by severe hypercapnic respiratory acidosis, manifestations that persisted even after the remission of pulmonary infection, raising the suspicion of an apnea syndrome. After excluding the causes of obstructive apnea, a cerebral CT scan was performed, revealing isolated fourth ventricle compressing the brainstem. The patient underwent neurosurgical intervention and postoperatively, the evolution was favorable, with remission of apnea crisis.

The Incidence of Electrolytes and Acid-Base Abnormalities in Diabetic Emergencies using the I-Stat Portable Analyser.

Diabetic patients with prolonged insulin insufficiency can present in the emergency department with life threatening ketoacidosis,el ectrolyte abnormalities,an d morbid arrhythmias. A quick and accurate determination of the metabolic abnormalities with rapid intervention is paramount in their management. The aim of this study was to determine the incidence of electrolyte and acid-base abnormalities in diabetic emergencies using the I-STAT point of care testing technique. The study involved thirty diabetic patients admitted into the accident and emergency department of the Lagos University Teaching Hospital. Informed consent was obtained from all participants. Blood samples were obtained for estimation of electrolytes and acid-base using point of care testing (I-Stat portable analyser). A Multistix urine strip (Bayer Diagnostics Reagent Strips) was used for urine analysis to detect the presence of ketones. The mean age was 60.37 ±10.45 (40-79) years, made up of 21(70%) females and 9(30%) males, with a mean duration of diabetes mellitus of 6.5 ±3.56 years. Hyperglycaemia was observed in 70%, and hypoglycaemia in 20%.T he commonest electrolyte abnormality was hypokalaemia (56.67%)followed by hyponatremia (50%).Other abnormalities included hyperkalaemia (10%) and hypernatremia (3.3%). Abnormalities of acid base balance included low pH (20%), low TCO 2 (16.67%), high TCO 2 (16.67%), high PCO 2 (46.67%),and low PCO 2 (23.33%). The results indicated that in diabetic emergencies the commonest electrolyte abnormality was hypokalaemia followed by hyponatremia, and the least was hypernatremia. Key words: Diabetes mellitus, I-stat portable analysers, electrolyte and acid-base abnormalities

Renal Disease in Sickle Cell: Clinically Varied and Associated with Increased Mortality

AbstractAbstract 90▪▪This icon denotes a clinically relevant abstractThe Walk-Phasst Study of sickle cell disease (SCD) affords a unique opportunity to examine renal function in a large number of adults with SCD. Extensive clinical and laboratory data were obtained on 463 adults with HbSS and 127 adults with HbSC. Where possible, correlates for estimated glomerular filtration rate (eGFR, calculated by the 4-value MDRD equation) and albuminuria/proteinuria were also evaluated in historical data, from SS adults in the CSCCD cohort and the Multicenter Study of Hydroxyurea (MSH) in sickle cell disease.Adjusted decline in eGFR was more rapid in SS compared with SC, at −2.6 and −0.92 ml/min/1.73 m2/year, respectively (p<0.001). In SS, similar declines in cross-sectional eGFR with age were seen in adults in the CSCCD (n=705) and MSH (n=298) cohorts, at −2.9 and −1.9 ml/min/year (BSA corrected), respectively. Multivariate analysis of the SS cohort in of Walk-Phasst revealed that depressed eGFR values were associated with an elevated estimated pulmonary arterial systolic pressure (as reflected in a higher tricuspid regurgitant jet velocity, measured by echocardiogram, p=0.007) and with evidence for inflammation (an elevated white blood cell count, p=0.018). In SC adults, in contrast, lower eGFRs were primarily associated with a diminished erythroid reserve (depressed absolute reticulocyte counts, P=0.005).Albuminuria (≥30 mg albumin/gm creatinine) was detectable in 66 and 41 % of adults with HbSS and HbSC in Walk-Phasst (185/287 evaluable SS and 25/61 evaluable SC, p=0.001). In Walk-Phasst, albuminuria in SS was associated with evidence of increased red cell destruction (lower total hemoglobin (P=0.07), higher LDH (P<0.001), and higher reticulocyte count (P=0.017)). In SC, albuminuria was associated with a higher LDH (P=0.01). 159/657 (24%) of adult SS subjects in the CSCCD cohort had trace to 4+ proteinuria, using a method (urine dipstick analysis) that is less sensitive and less quantitative than the albumin-to-creatinine ratio used in Walk-Phasst. Multivariate analyses again suggested a strong association between a depressed Hgb and proteinuria (P<0.001) in CSCCD, and LDH was also associated with proteinuria, in univariate analyses (P<0.001). In Walk-Phasst the absence of albuminuria in all subjects with SCD was associated with lesser mortality in multivariate analyses (Hazard ratio 0.62 (0.4–0.9, P=0.02). No similar association was seen between eGFR and mortality.Subjects with SS in Walk-Phasst had depressed serum bicarbonate levels, of 23.8±3.4 compared with 24.7±3.2mEq/dL in SC (p<0.005) and 24.8±3.3 mEq/dL in the non-CKD general population (Shah et al, 2009). In multivariate analyses, acidemia was associated with both increased destruction and decreased production of red cells, e.g. higher EPO (P=0.003) and total bilirubin levels (P<0.001), but lower reticulocyte counts (P=0.06). Impaired physiologic functioning in acidemic subjects with HbSS, manifest as a depressed 6MWD (P<0.001) and a lower eGFR (P<0.001), was seen. No effect of bicarbonate level on mortality in SCD patients was evident in Walk-Phasst.In conclusion, renal function is perturbed in sickle cell syndromes in several ways, including more rapid decrement in eGFR, highly prevalent albuminuria, and, in SS, marked abnormalities in acid-base balance. Albuminuria is associated with anemia in two large cohorts of sickle cell disease patients and, in Walk-Phasst, with evidence for enhanced red cell destruction. Importantly, albuminuria correlated with an increased risk for mortality in sickle cell disease.(We acknowledge the many contributions made by the Walk-PHASST Investigators: Badesch DB, Barst RJ, Castro OL, Girgis RE, Gibbs JS, Goldsmith JC, Hannoush H, Hassell KL, Kato GJ, Krishnamurti L, Lanzkron S, Machado RF, Morris CR, Novelli EM, Rosenzweig EB, Sachdev V, Schraufnagel DE, Taylor JG 6th.) Disclosures:No relevant conflicts of interest to declare.

Acid–base pathophysiology after 130 years: confusing, irrational and controversial

The interface between acid-base physiology and blood gas interpretation is historically both stimulating and turbulent. Since the pioneering work of many celebrated names in the history of acid-base disorders, such as Arrhenius, Henderson, Hasselbalch and many more to follow, substantial progress in acid-base knowledge has been made over the last 130 years. Out of the chaos of competing definitions, concepts and terms, many have tried to bring an orderly approach to acid-base balance. Nevertheless, the mechanisms responsible for acid-base balance are unfortunately still incompletely understood, and moreover, considerable controversy has developed over the past decade as to how to classify and understand acid-base derangements occurring as a result of abnormalities in acid-base balance. Analysis of the medical literature, including a MEDLINE and EMBASE search, and a search of internal medicine, critical care and nephrology textbooks and reference lists, was performed on topics pertaining to the assessment and management of acid-base disorders, focusing on the gaps in our knowledge and on controversial issues. Several confusing, irrational and controversial issues concerning acid-base nomenclature, reference values, pathophysiology, assessment of acid-base disorders and therapy were found. Despite huge progress in acid-base knowledge, several confusing, irrational and controversial issues remain. Suggestions to reduce the confusion are provided.

Cord Blood Acid-Base Status at Delivery After Successful External Cephalic Version

Pregnancies after successful external cephalic version (ECV) are generally regarded as being normal. Nevertheless, increased levels of thyroid-stimulating hormone, an indicator of perinatal stress, recently were reported in cord blood in infants delivered vaginally after successful ECV. This retrospective study was an attempt to learn whether such infants are compromised, in particular, whether there are abnormalities of acid-base balance in cord blood. The 89 study cases were singleton deliveries at or after 37 weeks gestation that followed successful version. The same number of pregnancies with spontaneous cephalic presentation made up the control group. Women in the ECV group were significantly older, but there were no significant differences in birth weights or Apgar scores. Women in the ECV group had significantly more emergency cesarean deliveries than did control women. Cord blood arterial and venous acid-base parameters were similar in the 2 groups, as were the proportions of fetuses with a cord blood pH less than 7.20. Even after adjusting for maternal age, gestational age at delivery, mode of delivery, birth weight, spontaneous or induced labor, and duration of labor, differences in cord blood pH between the ECV and control groups were not significant. These findings support the use of ECV for term breech presentation. These infants may be more vulnerable biologically to the stress of labor, but with adequate intrapartum care, they should not be at increased risk of being acidotic at the time of birth. ECV may entail more emergency section deliveries, but it does lessen the incidence of cesarean deliveries for breech pregnancies.

Acid-Base Balance: Biochemistry for All Surgeons

Abnormalities of acid-base balance can be crucial in a postoperative patient. Surgeons should be aware of the means of diagnosing and treating any divergence. This review is an aid to the surgeon to help understanding acid-base balance problems.

Glucose-induced insulin secretion in uremia: relation with acid-base balance and effects of bicarbonate administration.

In order to evaluate effects of metabolic acidosis on glucose metabolism in uremia, we studied, by an intravenous glucose tolerance test (IVGTT), 46 patients with severe chronic renal failure divided into three groups according to their blood bicarbonate (BB) values: group A formed by 15 patients without or with light metabolic acidosis (BB > or = 20 mEq/1); group B formed by 18 patients with moderate metabolic acidosis (16 < or = BB < 20 mEq/1); group C formed by 13 patients with severe metabolic acidosis (BB < 16 mEq/1). In 8 patients of group B (subgroup B1) and in 8 of group C (subgroup C1), IVGTT was also repeated after adjustment of acid-base balance by intravenous or oral bicarbonate administration. Twenty-nine healthy volunteers formed the normal controls. For each test, glucose constant decay (K), immunoreactive insulin (IRI) area and C-peptide (C-p) area response, insulinogenic index (IGI) and insulin resistance index (RI) were calculated. Compared to controls, all uremic groups showed significantly lower values of K and IGI and significantly higher values of C-p area and RI. In group C, RI was significantly higher than in groups A and B. No differences were found in the other glucose metabolism parameters among the uremic groups. After bicarbonate administration, subgroup C1 showed a significant decrease in RI and a rise in K values, while subgroup B1 showed no changes in glucose metabolism parameters. From these data, we infer that abnormalities of acid-base balance do not affect insulin response but severe metabolic acidosis may play an additional role in the insulin resistance of uremic patients.

Postoperative metabolic alkalosis following general surgery: Its incidence and possible etiology

A prospective clinical study was performed on 293 patients, in order to elucidate the abnormalities in acid-base balance following general surgery. Six arterial blood gas and pH determinations were taken from each patient before surgery and on postoperative days zero, one, three, five and seven. A total of 1699 determinations were obtained. Although the majority of patients (87.5 per cent) had a normal acid-base balance before surgery, a postoperative metabolic alkalosis was seen in 50.5 per cent of the patients. However, there was an extremely low incidence of other postoperative acid-base abnormalities, apart from a transient increase in metabolic acidosis on the operative day. A significantly high mortality rate (32.3 per cent) was observed in 31 patients who had continuous metabolic alkalosis during the postoperative period. An excessive bicarbonate load resulting from the administration of fresh frozen plasma following surgery was strongly suggested as one of the major causes of postoperative metabolic alkalosis. Further investigation is required to elucidate the mechanism of the generation of metabolic alkalosis induced by the postoperative bicarbonate load in surgical patients.

Slide rule for the evaluation of compensation in primary metabolic or respiratory acidosis.

The body normally shows only partial compensation of serious abnormalities in acid-base balance. Data based upon previously reported studies of the degree of compensation in uncomplicated cases of primary respiratory or metabolic acidosis have been adapted to a slide rule. The slide rule indicates whether the degree of compensation is normal or abnormal as a result of complicating metabolic or respiratory factors, based upon the pCO2 and base excess values.

Clinical disorders of acid-base equilibrium.

Most of the clinical abnormalities of acid-base balance are self-limited. They relate either to an increase in the number of hydrogen ions entering the extracellular fluid (ECF) or to an extracorporeal loss of base. Sustained abnormalities most often result from disease of one of the two major organs concerned with acid-base regulation, the lung or the kidney. A rational approach to the diagnosis and management of acid-base abnormalities requires an understanding of the physiologic processes concerned with hydrogen ion regulation. Conceptual clarity in this area has been abetted by the widespread utilization of the Bronsted-Lowry concept of acids and bases. In this view, simply stated, an acid is a proton donor and a base is a proton acceptor. 1 Buffers minimize changes in hydrogen ion concentration by converting strong (completely ionized) acids and bases into weaker (less completely dissociated) acids and bases, respectively. In man, the major physiologically active buffer

RULES OF EVIDENCE APPLIED TO TREATMENTS OF NEONATAL HYPOXEMIA AND ACIDOSIS

BIOCHEMICAL MONITORING of the low birth weight infant during the first 24 hours of life frequently reveals abnormalities of acid-base balance and hypoxemia; these anomalies are very striking in infants with clinical signs of respiratory distress. The clinician is then faced with two problems: the first in diagnosis, the second in treatment. In the past few years certain regimes for respiratory distress have been recommended with varying degrees of fact and forcefulness. These include the careful maintenance of thermal balance to keep oxygen consumption at a minimum, correction of acidosis by NaHCO3 or THAM in rapid or slow infusion, adequate oxygenation sometimes requiring an inspired O2 concentration above 40%, assisted ventilation (either through a tracheal tube or by a negative pressure tank), and, finally, administration of agents acting on vasomotor tone.