Blood acid-base imbalance

Some Causes of Blood Acid-Base Imbalance... 

Alterations of HCOj and CO2 dissolved in plasma are characteristic of acid-base imbalance. Its value has most significance in the context of other electrolyte values and with blood gases and pH values. The full clinical significance of the determination of total CO2 wiU become apparent in the following discussion of acid-base physiology. 

Acidosis seen during cardiac arrest results from decreased blood flow and inadequate ventilation. Chest compressions generate approximately 20% to 30% of normal cardiac output, leading to inadequate organ perfusion, tissue hypoxia, and metabohc acidosis. In addition, the lack of ventilation causes retention of carbon dioxide, leading to respiratory acidosis. This combined acidosis produces not only reduced myocardial contractility and negative inotropic effect but also the appearance of arrhythmias because of a lower fibrillation threshold. In early cardiac arrest, adequate alveolar ventilation is the mainstay of control to limit the accumulation of carbon dioxide and control the acid-base imbalance. With arrests of long duration, buffer therapy often is necessary. 

What type of acid-base imbalance in the blood is caused by... 

Chapter 4 focuses on fluid volume imbalances (i.e., hypervolemia and hypovolemia) and related symptoms and treatments. Chapters 5 through 9 present the major electrolytes and concepts related to excessive or insufficient blood levels of sodium, potassium, calcium, magnesium, and phosphate. Chapter 10 focuses on acid-base imbalances and discusses the procedures needed to determine the underlying source of the imbalance and the appropriate treatments and patient care needed to address the imbalance. Chapters 11 and 12 contain presentations of developmental conditions and disease conditions that involve imbalances in fluids, electrolytes, and acid-base, with the aim of enabling the reader to apply the concepts learned in earlier chapters of the book. 

Symptoms of hypokalemia may indicate the need for a urinalysis and blood tests to determine the amount of potassium being excreted by the kidneys and related electrolyte and acid-base imbalances. 

Burn injury fluid loss and increased blood viscosity with blood and muscle damage blocked microcirculation and decreased renal perfusion decreased perfusion of renal cells - ischemia necrosis tubular necrosis and decreased renal function fluid, electrolyte, and acid-base imbalance... 

Treatment for the respiratory damage involves oxygen supplements, intubation, and artificial ventilation when indicated, as well as the use of a hyperbaric chamber to remove carbon monoxide, if needed. Any restriction to the chest owing to burned skin is removed surgically. The nurse must monitor arterial blood gases and oxygen saturation levels to determine the effectiveness of treatment. In addition, the nurse should monitor for signs of acidosis and related acid-base imbalances. <3 ... 

This electrolyte plays a vital role in the acid-base balance of the body. Bicarbonate may be given IV as sodium bicarbonate (NaHC03) in the treatment of metabolic acidosis, a state of imbalance that may be seen in diseases or situations such as severe shock, diabetic acidosis, severe diarrhea, extracorporeal circulation of blood, severe renal disease, and cardiac arrest. Oral sodium bicarbonate is used as a gastric and urinary alkalinizer. It may be used as a single drug or may be found as one of the ingredients in some antacid preparations. It is also useful in treating severe diarrhea accompanied by bicarbonate loss. 

Table VI summarizes the material presented in the previous discussion. It correlates the changes in oxygen and carbon dioxide partial pressures, showing the pathological causes for the imbalances. In addition, it contains the various diagnoses of acid-base abnormality (using same numbers as in Figures 1 and 2 and Table I). Considering the format of Table VI as a tic-tac-toe set-up, we can label the nine portions by the letters A-I for identification in Table VII which gives examples of various conditions associated with such blood gas abnormalities (20-30).

The volume to be infused and rate of delivery are only part of the therapeutic plan for fluid therapy, albeit the most important in acute resuscitation. The electrolyte and acid-base status of the horse should also be considered and fluids chosen to help to correct physiological imbalances. Unfortunately, it is not possible to predict electrolyte and acid-base disturbances accurately based on clinical signs. Seemingly similar clinical presentations may have a quite different pathophysiology (Brownlow Hutchins 1982, Svendsen et al 1979). The recent availability of relatively inexpensive, portable blood gas and electrolyte measuring equipment (Grosenbaugh et al 1998) has made determining the acid-base status possible in ambulatory equine practice and allows the field veterinarian to monitor and treat these disturbances. As stated earlier, in the absence of specific laboratory information, fluid therapy should probably be limited to isotonic polyionic crystalloid fluids, possibly with the addition of 10-20 mEq/1 potassium chloride in the maintenance phase. 

The treatment of acid-base disturbances should be directed at the imderlying cause and the specific plasma constituent imbalance. It is possible to determine the relative contributions of sodium, chloride, unidentified anions (principally lactate in horses) and protein to the metabolic component of acid-base disturbances by the use of equations based on the calculated base excess (Corley Marr 1998, Whitehair et al 1995). However, decisions on treatment can often be based on the absolute values of these blood constituents and it is only in complex disturbances, with changes in multiple plasma constituents, that the equations are usually necessary. 

In health, the alveolar membrane which separates the blood in the pulmonary capillaries and the alveolar gas is so thin that the blood equilibrates with alveolar gas in its transit through the lungs. The partial pressures in systemic arterial blood are within a few mmHg of those in alveolar gas. In the context of acid-base physiology, the partial pressures may be taken as being equal, although there are situations, such as thickening of the alveolar membrane or ventilation-perfusion imbalance, where this near equality is not maintained (Jennett, 1989, p. 217). 

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