ABG Flashcards
5 Causes of Respiratory Acidosis
Most pulmonary diseases (not PE): pneumothorax, pneumonia, COPD, acute asthma, pulmonary oedema, pleural effusion, ARDS, interstitial lung disease / respiratory depression (opiates and benzos) / neuromuscular (GBS, MG, MS, MND) / kyphoscoliosis / Pickwickian syndrome (obesity hypoventilation)
Type I respiratory failure definition
Low O2 (<60mmHG) and low or normal CO2 - ie blood vessels are all saturated with O2 (hyperventilation increases CO2 removal but not necessarily O2 sats
Type II respiratory failure definition
Low O2 with increased CO2 - inadequate alveolar ventilation
Causes of Type I resp failure
underventilated alveoli - pulm oedema/acute asthma, or venous blood bypass of ventilated alveoli (shunts) : pneumonia, obesity, bronchiectasis
Causes of Type II resp failure
COPD, drug overdose, MG, polyneuropathy, polymyelitis, muscle disorders
4 causes of Respiratory alkalosis causes
Psychological (hyperventilation), Cerebral event, PE, Respiratory stimulants (ie asprin OD)
4 causes of raised anion gap met acidosis
DKA / uraemia in AKI / Poisons (Methanol, alcohol, salycilates) / Lactic acidosis (underperfused)
5 causes of normal anion gap met acidosis
Severe diarrhoea/vomitting / Renal tubular acidosis / Pancreatic fistula / Addison’s disease / Hyperkalaemia
3 Causes of metabolic alkalosis
Hypokalaemia / severe vomitting/diarrhoea / pyloric stenosis
Anion gap equation
Na + K - (HCO3 + Cl)
ph 6.9 paCO2 2.48 HCO3 4.7 PaO2 17
DKA
Additional tests for DKA
blood glucose and test ketones in urine
Treat DKA
ABCDE! Fluids, insulin with regular BM (consider bicarbonate)
Treat T1RF/T2RF
ABCDE - try and get O2 sats to 88-92 or higher. only 1% are CO2 retainers. Consider mechanical ventilation or non invasive ventilation. Correct underlying cause
