acid-base q Flashcards
Why use arterial blood?
essential for assesment if respiratory functions
Why use a closed samplying method?
To avoid air contamination, which can give increased pO2 result
What are the effects of pC02 after contamination?
pCO2 may be decreased (shortly after sampling as CO2 evaporates into the air), or increased (in case of longer storage, produced by the metabolism of blood cells)
Why use ion equilibrated dry heparin?
normal heparin here can cause dilution error (of ion? donno)
Why take the body temp?
samples are analysed on standardized temperature 37°C. The solubility of gases is dependent on temperature, however, and the measured values need to be corrected to the temperature of patient.
What are the acid base parameters?
pH pCO2 HCO3- ABE TCO2 SBE
What are the effects of metabolic acidosis and metabolic alkalosis?
ACIDOSIS: Kussmaul-type breathing Hypercalcaemia Vomiting, depression Hyperkalaemia
ALKALOSI: Breathing-depression Muscle weakness – hypokalaemia hypocalcaemia Ammonia toxicosis
What kind of sample is taken for blood analysis?
Arterial samples are essential for assessment of respiratory function, but either venous or arterial samples can provide useful information on the metabolic status of the animal.
First step of acid base analysis?
Evaluate whether acidosis or alkalosis is present according to the pH!
Definition of acidosis?
an excessively acid condition of the body fluids or tissues.
Buffers/buffer systems (IC,EC,Vital,physiological)?
intracellular buffer: protein-proteinate
extracellular and generally: carbonic acid - bicarbonate
also use primary - secondary phosphate buffer
Metabolic parameters?
HCO3- and ABE and SBE
Function of buffer?
A buffer is a solution that can resist pH change upon the addition of an acidic or basic components. It is able to neutralize small amounts of added acid or base
What is ABE?
Actual base excess
Titratable acidity or basicity; the amount of acid or base
needed to equilibrate blood to pH: 7.4
Types/which ions are measured?
analyzers analyze pH, CO2, HCO3- and also ions: Ca2+, Na+, K+, Cl-.
Define PH?
pH is a measure of hydrogen ion concentration, a measure of the acidity or alkalinity of a solution
What is cause of metabolic acidosis
HCO3- loss Incr acid intake Incr acid prod Cattle grain overdose ion exchange Hypercalcaemia
What is the effect of metabolic acidosis
KUssmaul breathing
Hypercalcaemia
Vomiting, depression
Hyperkalaemia
How do you treat metabolic acidosis
Adequate ventilation.
PH lower than 7.2: infusion therapy with alkaline fluid
What is cause of metabolic alkalosis
Incr alkaline intake Incr ruminate alkaline prod Decr hepatic ammonia catabolism (liver failure) Incr acid loss Ion exchange hypokalaemia
Effects of metabolic alkalosis
Treatment
Breathing depression hypo ventilation Muscle weakness . Hypokalaemia Hypocalcaemia Ammonia toxics is Arrhythmia
Treat electrolyte balance
Cause of respiratory acidosis
Upper airway obstruction
Pleural cavity disease: pleural effusion, pneumothorax
Pulmonary disease: pneumonia, pulm, oedema
Depression of central control of resp. : drugs toxins
Neuromuscular depression of resp muscles
Muscle weakness even hypokAlaemia
Cardiopulmonary arrest
Effects of resp acidosis
Treatment
Dyspnoea, cyanosis, suffocation, muscle weakness, tiredness
Assist ventilation: fresh air or o2 oxygen therapy
Treatment of cause: eg diuretic treatment in fluid accumulation in lungs, remove fluid from pleural space etc
Mildly sedating drugs to decr fear\ excitement
Causes of resp alkalosis
Incr loss of cod; hyperventilating
- excitation
- forced ventilation (Anaesthesia)
- epileptic seizures
- fever, hyperthermia
- interstitial lung disease
Effects of resp alkalosis
Hyperoxia. Incr pCO2 : pO2ratio
Incr elimination of HCO3- by kidneys
Treatment of resp alkalosis
Mild sedative drugs in case of hyperexcitaion
Incr pCO2 level by closing nostrils, pull paper bag on nose and breath som eminutes
Blood gas analysis: hypoventilation causes
Upper airway obstructinion
Pleural effusion
Drugs or disorders affecting central control of resp
Neuromuscular disease affecting resp system
Overcompensation of metabolic alkalosis
Effects of hypoventilation (blood gas )
Dyspnoea, cyanosis
Treatment of hypoventilation
Assisting ventilation, assisted breathing, oxygen therapy
Diuretic treatment
Sedating treatment
Causes of hyperventilation
Iatrogen forced ventilation during Anaesthesia
Seizures, epilepsy
Excitation
KUssmaul type breathing; compensation of seveefe metabolic acidosis
