Anion gap acidosis

Because clove cigarettes also contain tobacco, they carry all of the hazards of regular tobacco smoking (Council on Scientific Affairs 1988). Several cases of serious medical illness have been associated with clove cigarettes in the United States (Guidotti et al. 1989). These include cases of hemorrhagic pulmonary edema, pneumonia, bronchitis, and hemoptysis. Because eugenol anesthetizes the respiratory tract, it inhibits the normal gag reflex and has led to aspiration pneumonia in at least one case. Accidental overdoses in children have led to CNS depression, urinary abnormalities, and anion-gap acidosis. These cases were treated successfully with supportive measures (Lane et al. 1991). 

Three stages of ethylene glycol overdose occur. Within the first few hours after ingestion, there is transient excitation followed by CNS depression. After a delay of 4-12 hours, severe metabolic acidosis develops from accumulation of acid metabolites and lactate. Finally, delayed renal insufficiency follows deposition of oxalate in renal tubules. The key to the diagnosis of ethylene glycol poisoning is recognition of anion gap acidosis, osmolar gap, and oxalate crystals in the urine in a patient without visual symptoms. 

Table 58-1 Examples of Drug-Induced Anion Gap Acidosis. ...

The chloride (CD) ion is the most abundant anion in the ECF (see Table 46-2), In the absence of acid-base disturbances, Cr concentrations in plasma will generally follow those of Na. However, determination of plasma CD concentration is useful in the differential diagnoses of acid-base disturbances and is essential for calculating the anion gap (see Increased Anion Gap Acidosis [Organic Acidosis] section later in this chapter). Fluctuations in serum or plasma Cl have little clinical consequence, but do serve as signs of an underlying disturbance in fluid and acid-base homeostasis and can be an aid in differentiating the cause of these disturbances. 

Figure 46-14 Simple Gambeigram depiction of normal gap, anion gap acidosis, and nonanion gap acidosis. Cations, Na and are in left bar for each condition, whereas measured (Cl and HCOj) and unmeasured (U ) anions are in right bar for each condition.

In contrast to high anion gap acidoses, m which bicarbonate is consumed in buffering excess the cause of acidosis in the presence of a norma anion gap is the loss of bicarbonate-rich fluid from eitlrer the kidney or gastrointestinal tract. As bicarbonate is lost, more Cl ions are reabsorbed with Na or to maintain electrical neutrality so that hyperchloremia ensues (see Figure 46-14). Normal anion gap acidosis can be divided into hypokalemic and normokalemic acidoses, which can be helpful in the differential diagnosis of this type of disorder (see Table 46-4). 

Hyperkalemic Normal Anion Gap Acidosis (Renal Tubular Acidosis Type IV)... 

All patients developed a compensatory metabolic acidosis due to chronic hyperventilation. Respiratory alkalosis was thought to have developed because of capillary leak into the lungs producing borderline or frank pulmonary edema. After several days a superimposed normal anion gap acidosis developed from dilution by large volumes of saline fluid resuscitation. The authors found no defects in renal handling of calcium, phosphorous, or magnesium. There was no evidence of a renal acidification defect or renal tubular acidosis. 

Clove oil Contains 80-90% eugenoi. Anion gap acidosis and CNS depression after acute ingestion. Ciove cigareties may cause irritant tracheobronchitis, hemoptysis. 

After a delay of 4-12 hours, evidence of intoxication by metabolic products occurs, with anion gap acidosis, hyperventilation, convulsions, coma, cardiac conduction disturbances, and arrhythmias. Renal failure is corn-men but usually reversible. Pulmonary edema and cerebral edema may aisc cccur. Hypocalcemia with tetany has been reported. 

B. Ingestion of fomtaldehyde solutions may cause severe corrosive esophageal and gastric injury, depending on the concentration. Lethargy and coma have been reported. Metabolic (anion gap) acidosis may be caused by formic acid accumulation from metabolism of formaldehyde or methanol. 

Isopropyl alcohol is widely used as a solvent, an antiseptic, and a disinfectant and is commonly available in the home as a 70% solution (rubbing alcohol). It Is often ingested by alcoholics as a cheap substitute for liquor. Unlike the other common alcohol substitutes methanol and ethylene glycol, isopropyl alcohol is not metabolized to highly toxic organic acids and therefore does not produce a profound anion gap acidosis. Hospitals sometimes color isopropyl alcohol with blue dye to distinguish it from other clear liquids this has led abusers to refer to it as blue heaven. ... 

At very high serum levels (> 1000 mg/L) after large ingestions, other metabolic and electrolyte abnormalities may be observed, including an increased anion gap acidosis, hypocalcemia, and hypernatremia. 

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