An Approach to the Problems of Acid-Base Balance

Abstract

1. The existing methods for assessing states of acidosis are discussed with particular reference to non-respiratory acidosis. Most of these methods are based either on the Henderson-Hasselbalch equation or on the direct extrapolation of in vitro studies on blood to the whole animal. The evidence available shows that these methods cannot be used to obtain an accurate assessment of disturbances of acid-base balance in the whole animal.2. The experiments were designed to investigate the acid-base parameters of an animal when a respiratory acidosis was superimposed on a non-respiratory acidosis caused by the infusion of N HC1; from these experiments it was possible to construct COz titration curves at various levels of non-respiratory acidosis. 3.A scheme which is based upon the C02 titration curves, has been proposed for assessing an acute acid-base disturbance in terms of its respiratory and non-respiratory components.4. The use of sodium bicarbonate to correct a non-respiratory acidosis was investigated, and it was shown that the amount of sodium bicarbonate required varied with the rate of infusion. No firm predictions could be made regarding the dose of bicarbonate required, but from the results of the present experiments an infusion rate of 0.1 mEq kgg' min-' is recommended in dogs. I N T R O D U C T I O NAcid-base balance is an aspect of physiology which has engaged the attention of biochemists, clinicians and physiologists. Unfortunately due to defects in communication between these disciplines there has been a considerable degree of confusion over both the terminology and the concepts involved.A basic difficulty is that it is not possible to measure either the hydrogen ion concentration or its activity in physiological fluids. The pH numbers provided by electrometric measurements Correspondence : Professor R. J. Linden,

The effect of atenolol on the spontaneous and reflex activity of the sympathetic nerves in the cat: influence of cardiopulmonary receptors

“…(1 mEq ml-1) were given as necessary to correct for the presence of any non-respiratory acidosis using the in vivo titration curves of Kappagoda, Linden & Snow (1970). Rectal temperature was monitored and maintained between 370 and 38°C.…”

The Atrial Receptors Responsible for the Decrease in Plasma Vasopressin Caused by Distension of the Left Atrium in the Dog

“…; the oesophageal temperature and the pH, Pco, and PO of arterial blood were monitored and maintained within normal limits, as previously described (Kappagoda, Linden & Snow, 1970). Each ureter was catheterized through a midline suprapubic incision and the urine was collected and the volume measured every 10 min.…”

Responses of slowly and rapidly adapting receptors in the airways of rabbits to changes in the Starling forces.

“…Cardiovascular pressures, electrocardiogram and action potentials were recorded on light sensitive paper as described previously (Kappagoda et al 1987). The arterial P., and pH of the animals were maintained within physiological limits (see Kappagoda, Linden & Snow, 1970). The temperature of the animal was monitored by a thermistor placed in the rectum (Yellow Springs Instruments Co., Yellow Springs, OH, USA) and maintained at 37 + 1°C using heating lamps.…”