Skills Flashcards
When are ABGs superior to VBGs?
If you need PaO2 or in severe shock/Hypercapnia/Lactate >2
Causes of respiratory acidosis
Decreased respiratory drive
Decreased chest wall movement
Chronic obstruction
Causes of respiratory alkalosis
Increased rep drive
Hypoxaemia induced- Altitude
What does an increased anion gap mean?
Increased acid production or ingestion
What does a decreased anion gap mean?
Decreased acid excretion or loss of HC03
Increased anion gap metabolic acidosis causes
Lactate Urea Ketones Aspirin OD CO
Decreased anion gap metabolic acidosis causes
Lithium toxicity
Inc Ca
Inc K
Inc Mg
Normal gap metabolic acidosis causes
Addisons, RTA
What does Aspirin OD cause
Metabolic acidosis and Respiratory alkalosis as compensation
Causes of metabolic alkalosis
GI loss of H+
Renal loss of H+- Nephrotic, Diuretics, Conn’s
What does base excess >2 mean?
Increased Bicarb
Met alkalosis or comp.Resp acidosis
What does base excess
Decreased Bicarb
Met acidosis or comp.Resp Alkalosis
In terms of compensation what does a normal PH indicate?
Fully compensated
If still abnormal then it is partially compensated
System for CXR interpretation
Demographics
RIPE
A->E
What does RIPE mean in relation to CXR interpretation?
Rotation- Clavicles and spinous processes
Inspiration- 5-6 Ant.Ribs
Penetration- Vertebrae through mediastinum
Exposure- Can you see it all?
What is ABCDE in relation to CXR interpretation?
Airway- Deviation?
Breathing- Pleura, Collapse, Consolidation, hilar, reticular shadowing
Circulation- Heart size, Heart position, shape, Great vessels
Diaphragm- Shape, Costophrenic angles, Air below?
Extra- Bones and soft tissue
Sail sign?
Lower lobe collapse
Veil sign
Upper lobe collapse
System to interpret an AXR?
Demographics Bowels (+ pother organs) Bones Calcification (BBC)
Diameter of the DB, LB and caecum?
3, 6, 9 CM
What does the coiled spring sign suggest?
SB obstruction
Valvulae conniventes become more prominent
How does faeces look on an AXR?
Mottled
What does the coffee bean sign suggest
Volvulus
Can also be the ‘fetal sign’ in the sigmoid
What suggests pneumoperitoneum?
Double wall sign- inner and outer wall visible of abdomen
SHOULD ONLY SEE INNER WALL
Also look for air under diaphragm on CXR
What is a lead pipe sign?
No haustra LB suggests IBD
What does toxic mega colon look like on AXR?
Dilated colon
Possible causes of calcification/artefact on AXR?
Gallstones, Renal calculi, Pancreatic/vascular/costochondral calcification
Surgical clips
Ureteric stents
Structure for ECG interpretation
Demographics Rate and Rhythm Axis P wave PR QRS Rhythm strips QRS V1-V6 ST T Other- QT
How to calculate rate on an ECG
Total R X6
How to work out Axis on an ECG
I +II
1 +VE II -VE LAD
1 -VE 2 +VE RAD
P wave height
< 2 small squares
Normal PR length
3-5 small squares
Decreased PR?
Accessory conduction pathway
Explain what R wave progression is?
V1= Dominant S
V6= Dominant R
V3/4 is the transition point
What does it mean if the R wave transition point is after V4 on an ECG?
Chronic lung disease
RVH
What could it suggest if there is a dominant R wave in V1/2?
RVH
Post.MI
QRS length?
< 3 small squares
RBBB has what V1 and V6 QRS pattern?
V1= RSR1 V2= qRS
M->W
LBBB has what V1 and V6 pattern?
V1= rS V6= Monophasic R wave V5/6= Bunny ears
WM
Height of QRS in V5/6?
< 4 Big squares
If > 5 Big sqaures then LVH
Dominant R wave in V1 could suggest?
RVH
What defines ST elevation/Depression?
> 1 small sq
What causes a saddle ST segment?
Pericarditis
Tamponade
What causes a reverse flick ST segment?
Digoxin toxicity
Flat T waves
Hypokalaemia
In which leads is T wave inversion normal
III + aVR + V1
What should a normal QT be?
< 450ms
What does an enlarged QT predispose you to?
Polymorphic VT
Narrow Tachy and abn P
SVT
Broad tachy and no p
VT/VF
What represents a severe fluid deficit?
> 8% body Wx lost, Profound oliguria, CNS collapse
What do crystalloids do?
Water soluble Diffuse through semi-permeable membrane Can infuse rapidly in large volumes Short duration in circulation Saline/Hartmann's/Dextrose
What do Colloids do?
Not a solution
Suspension of finely divided particles in a continuous medium
If capillary permeability is normal then the particles stay in circulation and keep fluid with them!
Gelatins/Albumin/Blood/Starches
What is the sensitivity and specificity of D-Dimer?
50% Specificity 95% Sensitivity
Good for ruling people out
When is D-Dimer confounded?
Sepsis, Trauma, Surgery, Pregnancy
What does the PESI score do?
Predicts 30 day outcomes for PE
What is D-Dimer?
Fibrin degradation product