In-House Diagnostics Module 1 Flashcards
What is the minimum database?
PCV/TP
BG
BUN
Lactate
Blood smear
What is the extended database?
EPOC
Coags
Saline agg
Bloody typing
Arterial blood gas
Biochem
FELV/FIV
Urinalysis
What is PaO2 and SaO2
PaO2 = partial pressure of oxygen in arterial blood
SaO2 = measures HB saturation via pulse oximetry
What is oxygenation?
Measurement of oxygen in the blood
What is ventilation?
Measurement of CO2
What are causes of hyperventilation?
Low CO2
Pain/fear/stress
Decreased arterial O2 content
Neurological disease
Hyperthermia
Compensation for metabolic acidosis
What are causes of hypoventilation?
High CO2
Airway obstruction
Neurological disease/drugs
Neuromuscular disease
Restrictive pleural disease
Respiratory muscle fatigue
What are the 4 types of acid/base disturbances?
Respiratory alkalosis - removal of CO2 by ventilation more than it is produced
Respiratory acidosis - Retention of CO2 due to alveolar ventilation not keeping up with CO2 production
Metabolic alkalosis - primary gain in base or loss of acid
Metabolic acidosis - a primary gain in acid of loss of base
What is the base excess?
It is a calculated value that reflects the non-respiratory portion of acid base, closely related to bicarb. It takes into account all the body’s buffering systems and is an estimate of how much base needs to be added or taken away from the system to achieve a normal pH
What can the anion gap be used to determine?
Can help determine whether the acidosis is caused by creation/addition of acid or loss of bicarb
- production of lactate/ketones
- lack of secretion - kidneys (resorb bicarb and secrete H+)
- ingestion of acid
Loss of bicarb rich fluid (D+)
What are the seven step to evaluating acid base
- pH
- Evaluate resp system - Evaluate PCO2 - the difference between PvCO2 should be is 5mmHg PCO2
- Evaluate metabolic system - based on the assessment of bicarb concentrations
- Base excess: represent metabolic portion of acid/base balance - measurement of how much base needs to be added or taken away to achieve a normal pH at a normal temp
- Looking at primary problem
pH = HCO3/CO2 - if pH and CO2 opposite directions = primary resp IF HCO3 changes in same direction as CO2 = metabolic primary - Evaluate compensatory changes - lung compensate quickly, kidneys take a few hours (gives an idea of chronicity)
- Assessment of oxygenation and ventilation - need arterial sample
What are causes of primary metabolic acidosis?
DUEL
D - DKA/diarrhea - ketones or loss of bicarb rich fluid
U - Uremic acidosis - kidneys
E - Ethylene glycol/aspirin
L - Lactic acidosis
What is the anion gap
(Na+K) - (Cl + HCO3) = anion gap
The anion gap is made up of unmeasured anions (cations/ions) such as lactate, ketones, toxins, uraemic toxins
Helps to categorise the metabolic disturbance and refine differential list
What are causes of metabolic alkalosis
- Vomiting - loss of acid
- Renal acid losses
- Loop diuretic administration
- NG suctioning - getting rid of acidic fluid
- compensatory
A metabolic acidosis with a normal AG means?
Suggestive of bicarb losses - most commonly through GI or renal