salicylates and Acid-Base-Imbalance

Topics: Acid-Base Imbalance; Charcoal; Diagnosis, Differential; Fluid Therapy; History, 19th Century; Humans; Poisoning; Renal Dialysis; Salicylates; Therapeutic Irrigation

Drug-induced acid-base disorders may be classified into four categories with respect to the mechanism. 1. Metabolic acidosis is induced by a large acid loads incurred from exogenous sources (e.g. NH4Cl, or toxin ingestion) or endogenous acid production (e.g. generation of ketoacids or lactic acids by alcohol or phenformin) or base loss (e.g. abuse of laxatives). 2. Metabolic alkalosis results from exogenous bicarbonate loads (e.g. milk-alkali syndrome) or effective extracellular fluid contraction, potassium depletion plus hyperaldosteronism (e.g. vomiting, diuretics, or licorice). 3. Renal tubular acidosis is induced by the drugs which mainly impair proximal and/or distal tubules (e.g. vitamin D, NSAID, acetazolamide or amphotericin B). 4. Respiratory acidosis or alkalosis results from drug-induced respiratory center depression or neuromuscular impairment (e.g. anesthetic, sedative overdosage or curare) or hyperventilation (salicylates, paraldehyde, epinephrine, or nicotine).

Topics: Acid-Base Imbalance; Ethylene Glycols; Humans; Methanol; Salicylates

Pseudohyperchloremia results in a very low or negative anion gap. Historically, the most common cause of this artifact was bromide poisoning. Bromide salts have been removed from most medications and bromism has become very uncommon. More recently, the introduction of chloride ion selective sensing electrodes (Cl-ISE) has generated a new cause of pseudohyperchloremia-salicylate poisoning. We describe 5 such patients and quantitate the error generated by this measurement artifact.. The magnitude of artifactual hyperchloremia generated by high salicylate levels was quantified in 5 patients by measuring chloride concentration with several Cl-ISEs from different manufacturers and with Cl-ISEs of different "ages," and comparing these results to measurements with a chloridometer (coulometric titration), which is free of the salicylate artifact.. Cl-ISEs from different manufacturers generated a wide range of artifactual chloride concentration elevation. Furthermore, the same Cl-ISE generated increasingly severe pseudohyperchloremia as it was repeatedly reused over time and "aged.". Salicylate interferes with measurement of the blood chloride concentration when a Cl-ISE is used. The severity of this artifact is related to the salicylate level, the specific Cl-ISE, and the "age" of the electrode. Toxic blood salicylate levels can generate marked pseudohyperchloremia, and consequently, an artifactual very small or negative anion gap. The large anion gap metabolic acidosis typical of salicylate poisoning is masked by this artifact. Salicylate has become the most common cause of pseudohyperchloremia, and physicians should immediately consider salicylate poisoning whenever the combination of hyperchloremia and a very small or negative anion gap is reported by the laboratory.

Topics: Acid-Base Equilibrium; Acid-Base Imbalance; Acidosis; Artifacts; Aspirin; Chlorides; Equipment Failure Analysis; Female; Humans; Ion-Selective Electrodes; Male; Middle Aged; Patient Care; Salicylates; Suicide, Attempted

Using the microdialysis technique and laser-Doppler flowmetry, we performed simultaneous measurement of salicylate hydroxylation and glutamate release along with local CBF in the ischemic penumbral cortex of rat brain subjected to normothermic transient middle cerebral artery (MCA) occlusion. Cortical CBF fell to 24 +/- 11% (mean +/- SD) during ischemia and recovered to 84 +/- 16% during reperfusion. Extracellular glutamate levels increased by 6.5-fold above baseline 10 min following MCA occlusion but subsequently returned to near baseline levels in spite of the persistent ischemia. Increase in 2,3- and 2,5-dihydroxybenzoic acid (DHBA) concentrations in the microdialysis perfusate was confirmed during both ischemia and reperfusion phase. Although the temporal profile and amount of salicylate hydroxylation were heterogeneous among individual animals, integrated 2,3-DHBA concentrations during reperfusion were correlated positively with integrated glutamate concentrations during ischemia and negatively with mean postischemic CBF. These relationships suggest a possible association of the enhanced production of 2,3-DHBA during reperfusion with larger amounts of intraischemic glutamate release and lower levels of post-ischemic CBF.

Topics: Acid-Base Imbalance; Analysis of Variance; Animals; Cerebral Cortex; Cerebrovascular Circulation; Chromatography, High Pressure Liquid; Free Radical Scavengers; Gentisates; Glutamic Acid; Hydroxybenzoates; Hydroxylation; Iron Chelating Agents; Ischemic Attack, Transient; Laser-Doppler Flowmetry; Male; Rats; Rats, Sprague-Dawley; Regression Analysis; Salicylates; Salicylic Acid

Systemic inflammatory response syndrome (SIRS) is characterized by body temperature abnormalities, tachypnea or hyperventilation, tachycardia, and leukocytosis or leukopenia. Although it is typically associated with a serious infection and referred to as sepsis, SIRS can stem from noninfectious causes, as well. We report the cases of four patients with toxic serum levels of salicylate (33.5 to 67.6 mg/dL) and SIRS, and we discuss mechanisms responsible for SIRS. Our patients showed temperature disturbances (35.5 degrees C to 39.8 degrees C), noncardiogenic pulmonary edema, and mixed acid base disturbances. Other abnormalities included coagulopathy (disseminated intravascular coagulation), encephalopathy, and hypotension. All four patients recovered from SIRS, probably due to early recognition and treatment; only one patient did not survive the hospitalization. Chronic salicylate toxicity should be considered as a cause of SIRS in the absence of a source of infection, since survival appears to be dependent on prompt diagnosis and management.

Topics: Acid-Base Imbalance; Adult; Anti-Arrhythmia Agents; Anti-Inflammatory Agents, Non-Steroidal; Aspirin; Chronic Disease; Disseminated Intravascular Coagulation; Female; Fever; Humans; Hypotension; Male; Middle Aged; Pulmonary Edema; Salicylates; Salicylic Acid; Systemic Inflammatory Response Syndrome

Topics: Acid-Base Imbalance; Child; Child, Preschool; Female; Humans; Infant; Male; Salicylates; Singapore

Toxic ingestions of acetaminophen and aspirin are clearly distinct in clinical presentations and in implications for laboratory medicine. In acetaminophen ingestion, the serum drug level is the single most important factor in the decision for or against therapy. In aspirin ingestion, the serum drug level is useful at its extremes--when so low as to indicate no need for therapy, and when so high as to indicate the need for dialysis. In the majority of infants and children with clinically significant salicylism, the serum drug level is in an intermediate range. For the management of these patients, the absolute level of salicylate in blood has much less significance than the laboratory assessment of the effects of salicylate on intermediary metabolism, acid-base status, and electrolyte and water balance.

Topics: Acetaminophen; Acetylcysteine; Acid-Base Imbalance; Aspirin; Child, Preschool; Female; Hepatic Encephalopathy; Humans; Infant; Liver; Male; Poisoning; Salicylates; Time Factors

This study examined the acid-base disturbances in 67 adults with salicylate intoxication. On admission, 66 patients had an acid-base distrubance. In contract to previous suggestions, however, only 25% of the patients had simple respiratory alkalosis. Unlike salicylate intoxication in children, 33% of these adults with salicylate intoxication had ingested additional drugs. These additional drugs generally were CNS depressants and were important determinants of the variety of the acid-base disturbance. Those patients who ingested additional drugs had a significantly lower incidence of respiratory alkalosis (P less than .005) and a higher incidence of respiratory acidosis (P less than .005) and acidemia (P less than 0.25). The incidence of acidemia correlated with the presence of neurological symptoms.

Topics: Acid-Base Imbalance; Acidosis, Respiratory; Adolescent; Adult; Aged; Alkalosis, Respiratory; Humans; Middle Aged; Salicylates