Chapter 3 Flashcards
What are the causes of hypernatraemia?
Four Ds:
Dehydration
Drips (too much IV saline)
Drugs - loop diuretics, steroids, lactulose
Diabetes Inspidus - can be caused by lithium, phenytoin, aminoglycosides - gentamicin, cisplatin,
(Cushings and Conns)
causes of micro vs normo vs macrocytic anaemia
micro: iron def, thalassemia
normo: chronic disease, blood loss, haemolytic anaemias, CKD
Macro: B12 def, liver disease, alcoholism, hypothyroidism, myeloma
What are causes of neutrophilia vs neutropenia?
neutrophilia: bacterial infection, inflammation, steroids
Neutropenia: viral infection, chemo/ radiotherapy, clozapine, carbimazole
What are the causes of thrombocytopenia vs thrombocytosis?
thrombocytopenia: infection, penicillamine, myeloma, heparin, DIC, ITP, HUS, TTP
Thrombocytosis: bleeding, inflammation, post-spleenectomy
What are the causes of hyponatraemia? Separate into different fluid statuses
Hypovolaemic: fluid loss, diuretics, addisons
Normovolaemic: SIADH (can be caused by carbamazepine or antipsychotics), hypothyroidism
Hypervolaemic: heart failure, renal failure, liver failure
Causes of hypo (DIRE) vs hyperkalaemia (DREAD)?
Hypo:
Drugs - diuretics, Inadequate intake/ loss, Renal tubular acidosis, Endocrine (cushings/ conns)
Hyper: Drugs - potassium sparing diuretics, ACE-i Renal failure Endocrine (addisons) Artefact DKA
Pre renal, renal and post renal causes of AKI?
Pre: Dehydration, renal artery stenosis
Renal: INTRINSIC Ischaemia --> acute tubular necrosis Nephotoxic Tablet e.g. abx, ACE-i, NSAIDs Radioogy contrast Injury - rhabdomyolysis Negatively bifringement crystals (gout) Syndromes - glomerulonephritis Inflammation (vasculitis) Cholestrol emboli
Post: anything obstructibe e.g. stone, tumour (RCC, lymphadenopathy or prostate cancer), anuerysm
What are the most nephrotoxic abx?
gentamicin, vancomycin and tetracyclines (doxycycine).
Causes of Prehepatic vs intrahepatic vs posthepatic jaundice?
pre: haemolysis
Hepatic: NAFLD, hepatitis, cirrhosis, malignancy, metbaolic, heart failure
Post: gallstone, drugs, cancer, PBC, PSC
How do you interpret a CXR?
Film Quality:
Projection (PA or AP)
Rotation (if distance between spinpus processes and clavicles is equal then no rotation)
Inspiration (7 ribs)
Structures:
Heart should be less than 50% width lungs in PA film
Look for consolidation on lungs (effusion = solid, pneumonia = fluffy, fibrosis = bilateral and honeycomb)
Trachea central
Widened mediastinum think trachea deviation or aortic dissection
Bone #s
Signs:
Costophrenic angle sharp (otherwise think effusion)
Air under RIGHT hemidiaphragm - bowel perforation/ recent surgey. Air under LEFT gastric bubble and normal
Triangle behind heart aka sail sign = L lower lobe collapse
Unclear apices = TB
Which was does the trachea lean in a CXR in pneumothorax vs collapse?
towards = collapse pneumothorax = away
Signs of heart failure (pulomary oedema)
Alveolar oedema (bat wings) Kerley B lines (interstitial oedema) Cardiomegaly Diversion blood to upper lobes so appear Dilated Effusions of pleura
How do you check a PaO2 using FiO2 on an ABG?
Always start with FiO2 –> you expect PaO2 to be higher
if the patient is on oxygen check by
approximately subtracting 10 from the FiO2
and if the PaO2
exceeds this calculated number then the patient is not hypoxic
What are the causes of resp/ met acidosis/ alkalosis?
Respiratory alkalosis: hyperventilation due to disease/ anxiety
Respiratory acidosis: think T2RF e.g. COPD, neuromuscular failure/ restrictive chest wall abnormalities
Metabolic alkalosis: vomiting, diuretics, Conns
Metabolic acisosis: lactic acisosis, DKA, renal failure, ethanol intoxication –> can use anion gap to narrow down
How can you tell if there is LVH on an ecg?
Height: add the largest deflection of the QRS in V1 to that in
V6 (in terms of large squares) and if the sum exceeds 3.5
large squares then left ventricular hypertrophy (LVH)
is present.
