ملخص

Acid and Base Disturbance

Blood = 7.35 – 7.45 (7.40)
< 6.8 or > 8.0 death occurs
Acidosis (acidemia) below 7.35
Alkalosis (alkalemia) above 7.45

If underlying problem is metabolic, hyperventilation or hypoventilation can help : respiratory compensation.
If problem is respiratory, renal mechanisms can bring about metabolic compensation.

Alkalosis

over excitability of the central and peripheral nervous systems.
Numbness
Lightheadedness
It can cause :
Nervousness
muscle spasms or tetany
Convulsions
Loss of consciousness
Death


Acidosis
depression of the CNS through decrease in synaptic transmission.
Generalized weakness
Severe acidosis causes
Disorientation
coma
death

Respiratory Acidosis

Carbonic acid excess caused by blood levels of CO2 above 45 mm Hg
causes
Acute conditons:
Adult Respiratory Distress Syndrome
Pulmonary edema
Pneumothorax

Chronic conditions:

Depression of respiratory center in brain
Paralysis of respiratory or chest muscles
Emphysema


Compensation: Kidneys eliminate hydrogen ion and retain bicarbonate ion

Signs and Symptoms of Respiratory Acidosis

Breathlessness
Restlessness
Lethargy and disorientation
Tremors, convulsions, coma
Skin warm and flushed due to vasodilation caused by excess CO2
Treatment
Restore ventilation
Treat underlying dysfunction or disease

Respiratory Alkalosis

pCO2 less than 35 mm Hg (hypocapnea

cause is sustained hyperventilation

high altitudes (Oxygen deficiency) Hyperventilation
Pulmonary embolisim
Acute anxiety
Stimulation of brain stem respiratory center
Treatment :Treat underlying cause
rebreathe into a paper bag


perioaral & digital tingling ,Tetany produce

Compensation for Metabolic Acidosis

Increased ventilation
Renal excretion of hydrogen ions if possible
K+ exchanges with excess H+ in ECF
( H+ into cells, K+ out of cells)

Metabolic Acidosis

HCO3- less than 24,Caused by:
Loss of bicarbonate through diarrhea or renal dysfunction
Accumulation of acids
Failure of kidneys to excrete H+

compensation…hypoventilation to increase PCO2

Metabolic Alkalosis
Bicarbonate excess -concentration in blood is greater than 24 mmol/L
Causes:
Excess vomiting = loss of stomach acid
Loop &Thiazide Diuretics (loss of H+ in urine)
Cushing syndrome , ,
primary hyperaldoteronism
Heavy ingestion of antacids
Severe dehydration