A diagram to facilitate the understanding and therapy of mixed acid base disorders

A diagram based on in-vivo relationships between arterial hydrogen ion activity (H+) and carbon dioxide tension (PCO2) in primary abnormalities of acid base homeostasis is presented. It is designed to facilitate the interpretation of pH data by including the 95% confidence limits described in patients with simple metabolic and respiratory acid base disorders. These bands have been formulated from observation of simple acid base abnormalities and indicate the appropriate respiratory or renal compensatory response to the primary pH defect. A plot which falls outside these limits therefore indicates the presence of a mixed acid base disorder. The diagram presents a physiological approach to clinical disorders of pH regulation demonstrating maintenance of intra-cellular fluid homeostasis during primary extracellular fluid disturbances. Diagnostic and therapeutic advantages are further illustrated and discussed in six case reports.

Acid-base equilibrium in Menière's disease

57 patients suffering from Meiere's disease have been examined: metabolic alkalosis has been found in 39 and metabolic acidosis in 4. Electrolytes (Na, K and Cl) were normal. Among the 31 subjects in the control series a slight metabolic alkalosis qas detected only twice. Follow-up of several patients, from one to three years, resulted in a realization of a parallel between metabolic disturbance and Meniere symptoms. A provocation test, by sodium bicarbonate oral administration, has beem attempted twice: in both instances alkalosis did increase strongly but, only once, vertigo was elicited. Meniere patients found in alkalosis were given acidifying drugs to normalize their acid-base equilibrium. Such treatment proved effective in preventing acute cochleo-vestibular crises and in improving tinnitus and deafness (in the fluctuating stage). On the interruption of treatment symptoms reappeared. The physiological-pathological significance of metabolic alkalosis in Meniere's disease still remains unclear and, consequently, this can be considered merely a predisposing factor in endolymphatic hydrops.

[Acute abdomen masking pyelonephritis (author's transl)]

Analysis of 10 case histories shows that the picture of the acute abdomen may predominate in acutely exacerbated pyelonephritis. Viscero-dermal reflexes with hyperalgesia and muscular defense, visero-visceral organ reflexes with shock, vomiting, meteorism and disturbances of intestinal motility and metabolic acidosis are temptations to laparotomy. Fever in particular, pathological urinalysis, renal acidosis and occasionally hyperchloremia suggest the diagnosis of "abdominal type of acutely exacerbated pyelonephritis".