Lab 2 Flashcards
Metabolic acidosis
Causes
- HCO3- loss: diarrhoea, kidney tubular disturbance
- increased acid intake: fruits, acidic silage, overdoce of acidic drugc etc,
- increased acid production: incr. lactic acid prod. due to anaerobic glycolysis
- Bo: grain overdose - voletaile acid overproduction
- incr. ketogenesis: ketosis due to starvation
- decreased acid excretion: renal failiure
- xenobiotics
Metabolic acidosis
Effects
- Kussmaul-type breathing - hyperventilation
- Hyprcalcaemia - incr. mobilisation from bones in case of long term acidosis, decr. binding of Ca to albumin
- Vomiting, depression
- Hyperkalaemia - decr. cardiac muscle activity
- In urine
Metabolic acidosis
Treatment
good ventilation, fresh air
if pH is lover than 7,2 = infusion therapy
Anion gap
Parameter used to determine the cause of metabolic acidosis
Reffereed range: 8-16 mmol/L
To maintin elecrtoneutrality - decr. HCO3- has to be balanced by Cl-
Normal anion gap
- Diarrhoea
- Early kidney failure
- Renal tubular acidosis
- Acidifying substances (NH4Cl)
Increased anion gap
- Azotaemia or uraemia
- Lactacidosis
- Ketoacidosis
- Toxicosis (ethylene glycol toxicosis)
Metabolic alkalosis
Causes
- Increased alkaline intake: overdose of bicarbonates, or feeding
rotten food - Increased ruminal alkaline production: high protein intake, low carbohydrate intake,
anorexia, hypomotility - Decreased hepatic ammonia catabolism (liver failure)
- Increased acid loss: vomiting, gastric dilatation volvulus syndrome, abomasal
displacement - Ion exchange: hypokalaemia: due to Henle loop diuretics remember H+/K+ pump!!
(paradoxical aciduria, see Pathophysiology lecture notes!!)
Metabolic alkalosis
Effects
- Breathing depression
- Muscle weakness - hypokalaemia
- Hypocalcaemia due to incr. binding ability of albumin
- Ammonia toxicosis
- Arrhythmia
- Paradoxal aciduria
Metabolic alkalosis
Treatment
In general enough to treat the underlying electrolyte imbalance
Respiratory acidosis
Causes
- Upper airway obstruction
- Pleural cavity disease: pleural effusion, pneumothorax
- Pulmonary disease: severe pneumonia, pulmonary oedema, diffuse lung
metastasis, pulmonary thromboembolism - Depression of central control of respiration: drugs, toxins, brainstem disease Neuromuscular depression of respiratory muscles
- Muscle weakness e.g. muscle weakness in hypokalaemia Cardiopulmonary arrest
Respiratory acidosis
Effects
Dyspnoea, cyanosis, suffocation, muscle weakness, tiredness
Respiratory acidosis
Treatment
- Assisting the ventilation - fresh air
- Treatment of the cause: e.g. diuretic treatment: in case of fluid accumulation in the
lungs, pulmonary oedema; specific cardiologic treatment: in case of underlying
cardiac disease; treatment of pneumonia, removal of fluid from pleural space etc.
Respiratory alkalosis
Causes
- Increased loss of CO2: hyperventilation
- excitation
- forced ventilation (anaesthesia) epileptiform seizures
- fever, hyperthermia
- interstitial lung disease
Respiratory alkalosis
Effects
- Hyperoxia, increased pCO2 : pO2 ratio, may lead to apnoea
- Increased elimination of HCO3- by the kidneys
Respiratory alkalosis
Treatment
Anxiolytic or mild sedative drugs in case of hyperexcitation. It is important to increase the pCO2 level by closing nose or nostrils, pulling paper sack on the nose until breathing normalizes (only for a few minutes).
Blood gas analysis
Goal
To assess the effectiveness of the gas-exchange in the lungs
x: during anaesthesia
Method: The blood gas analyzers directly measure the pCO2 and pO2 with ion specific electrodes
Hypoventilation (paCO2 > 45 mmHg)
Causes
- upper airway obstruction
- pleural effusion
- drugs or disorder affecting central control of respiration e.g. general anaesthesia
- neuromuscular disease, which affects on respiratory system, also muscle weakness
e. g. hypokalaemia - overcompensation of metabolic alkalosis
Hypoventilation (paCO2 > 45 mmHg)
Effects
- Dyspnoea
- Cyanosis
Hypoventilation (paCO2 > 45 mmHg)
Treatment
- assisting the ventilation e.g. assisted breathing, oxygen therapy
- diuretic treatment: in case of fluid accumulation in the lungs, pulmonary oedema; or in the thoracic cavity
- mildly anxiolytic/sedating treatment
Hyperventilation (Pa CO2 < 35 mmHg)
Causes
- iatrogen: forced ventilation during anaesthesia (also high FiO2)
- seizures, epilepsy
- excitation (mild frequently visiting the vet, extreme e.g. shock after accident)
- compensation of severe metabolic acidosis: Kussmaul-type breathing.
Anion gap formula
(Na + K) - (Cl + HCO3)
Definition of base excess
The amount of H+ ions that would be required to return the pH of the blood to 7.35
How does Ca and K change during acidosis
Hypercalcaemia and hyperkalaemia
SAT
Oxygen saturtion: Indicates the fraction of oxygen- saturated hemoglobin relative to the total Hb in the blood
venous: 75-80% arterial: 90-100%
