Metabolic Acidosis and Metabolic Alkalosis

Introduction

PH: measure of the concentration of hydrogen ions in a solution , and therefore of its
More than 7.45 indicate alkalinity.Less than 7.35 indicate acidity

Buffer system

A system which maintain hydrogen ion concentration unchanged, by dilution or by the addition of acid or alkaline

Acid base balance

The balance between the amount of carbonic acid and bicarbonate in the blood
Kidneys and lungs worked as a buffer system

kidneys

In respiratory and metabolic acidosis the kidney excrete H+ and conserve Hco3
In respiratory and metabolic alkalosis the kidney excrete Hco3 and conserve H+ to maintain balance

lungs

Under the control of brain's medulla, which include the reflex center of respiration
Lungs make adjustment of ventilation in response to the amount of CO2 in the blood

ACUTE AND CHRONIC METABOLIC ACIDOSIS

A clinical syndrome (disturbance) characterized by law PH and low bicarbonate
concentration

Causes

Direct loss of bicarbonate: diarrhea , diuretics, renal insufficiency, TPN (total parental nutrition ) without bicarbonate

Clinical manifestations

Headache, confusion, drowsiness, tachypnea, nausea, vomiting
When PH is less than 7 peripheral vasodilatation hypotension, cold skin, and shock

Diagnostic finding

ABG analysis (law bicarbonate level less than 22meq/l low PH less than 7.35

Medical management
Bicarbonate is administered , when PH is less than 7.1 and bicarbonate level is less than

ACUTE AND CHRONIC METABOLIC ALKALOSIS

Definition

A clinical syndrome ( disturbance ) characterized by a high PH and a high plasma bicarbonate concentration
Causes
Gain of bicarbonate or loss of H
Vomiting, gastric suction
Excessive using of alkaline ingestion from antacids containing bicarbonate or from use NaHco3 in CPR

Clinical manifestation

Symptoms related to low ionized CA++ ( hypocalcaemia
Tingling of fingers, toes, dizziness
Muscle spasm, troussean's sign ( tourniquet placed around the upper arm stimulate spasm in the muscles of the hand ), and chvostek's sign( spasm of the facial muscles by lightly tapping in the facial nerve ), seizures, depression and impaired memory

Diagnostic finding

ABG:PH more than 7.45
HCO3 more than 26 meq/l

Medical management

Treat the underlying causes such as vomiting, gastric suction
Instruct the patient to decrease using of alkaline ingestion
Administered of Nacl because it allows excreting bicarbonatel