PSA Flashcards
Give 6 examples of enzyme inducers:
“PC BRAS”
Phenytoin
Carbamazepine
Barbiturates
Rifampicin
Alcohol (chronic excess)
Sulfonylureas
How do enzyme inducers affect drug metabolism?
Increase P450 enzyme activity in the liver -> hastening drug metabolism -> reducing the drug’s therapeutic effect
How do enzyme inhibitors affect drug metabolism?
Decrease P450 enzyme activity in the liver -> slowing drug metabolism -> increasing the drug’s therapeutic effect
Give 9 examples of enzyme inhibitors:
“AO DEVICES”
Allopurinol
Omeprazole
Disulfiram
Erythromycin
Valproate
Isoniazid
Ciprofloxacin
Ethanol (acute intoxication)
Sulphonamides (sulfasalazine)
Name 7 drugs that should be stopped before surgery:
“I LACK OP”
Insulin
Lithium
Anticoagulants/antiplatelets
COCP/HRT
K-sparing diuretics
Oral hypoglycemics
Perindopril and other ACEi
How long before surgery should you stop lithium?
Day before
How long before surgery should you stop the COCP or HRT?
4 weeks before
How long before surgery should you stop perindopril and other ACEi?
The day of surgery
Name 9 things to check on every prescription chart:
PReSCRIBER:
Patient details
Reactions (any allergies plus the reaction caused)
Signed
Contraindications (any CI for each of the drugs prescribed)
Routes of each drug
IV fluids (do they need any? are they prescribed?)
Blood clot prophylaxis if needed
anti-Emetic if needed
pain Relief if needed
How will erythromycin interact with warfarin?
Increases warfarin’s anticoagulant effect, unpredictably raising the INR
Give 3 contraindications to antiplatelets and anticoagulants:
Active bleeding
Suspected bleeding
Risk of bleeding (e.g. prolonged PT due to liver disease, risk of haemorrhagic transformation follow ischaemic stroke)
Give 8 side effects of steroids:
“STEROIDS”
Stomach ulcers
Thin skin
Edema
Right and left heart failure
Osteoporosis
Diabetes
Infection (including candida)
cushing’s Syndrome
Give 5 safety considerations for prescribing NSAIDs:
“NSAID”
No urine (i.e. renal failure)
Systolic dysfunction
Asthma
Indigestion (of any cause)
Dyscrasia (clotting abnormality)
Give two possible side effects of beta blockers:
- Wheeze in asthmatics
- Bradycardia
Give 2 possible side effects of ACEi:
- Dry cough
- Electrolyte disturbances
Give 3 possible side effects of CCBs:
- Peripheral oedema
- Flushing
- Bradycardia (only some CCBs)
Give 4 possible side effects of diuretics:
- Electrolyte disturbances
- Renal failure
- Gout (thiazide like diuretics)
- Gynaecomastia (K-sparing)
Why should you never prescribe trimethoprim and methotrexate together?
Both are folate antagonists, together they can cause bone marrow toxicity leading to pancytopenia and neutropenic sepsis
Give an example of when it would be appropriate to stop/pause a patient’s methotrexate prescription:
During active infection
What electrolyte disturbances can the following drugs cause?
1. Loop diuretics e.g. furosemide
2. Thiazide diuretics & thiazide-like diuretics e.g. indapamide
3. K-sparing diuretics e.g. amiloride hydrochloride
4. ACEi e.g. ramipril
ALL diuretics can cause hyponatraemia (although if they cause dehydration, this can result in hypernatreamia)
1 & 2 = hypokalaemia
3 & 4 = hyperkalaemia
How long should you avoid giving VTE prophylaxis for following a stroke?
Varies across the UK but generally not for a few months
All insulin is given s/c - give one exemption to this rule:
short-acting insulin on a sliding scale e.g. actrapid and novorapid can be given IV
Give 4 causes of hypernatraemia: (hint - 4Ds)
Dehydration
Drugs
Drips - too much IV saline
Diabetes insipidus
Give 4 causes of hypokalaemia:
“DIRE”
Drugs - loop diuretics and thiazide diuretics
Inadequate intake or intestinal loss (D&V)
Renal tubular acidosis
Endocrine (cushing’s and conn’s syndrome)
Give 5 causes of hyperkalaemia:
“DREAD”
Drugs - K-sparing diuretics and ACEi
Renal failure (AKI and CKD)
Endocrine (addison’s)
Artefact (very common due to clotted sample)
DKA
Plus: rhabdomyolysis, tumour lysis syndrome
A raised urea normally indicates kidney injury - BUT if you have a raised urea with a normal creatinine and your patient is not dehydrated, what other important cause must you rule out?
In an upper GI bleed Hb is broken down by gastric acid into urea, and then absorbed into the blood -> raised urea, normal creatinine, not dehydrated!
Check if their Hb has dropped indicating a bleed.
How do you determine if a patient’s levothyroxine dose needs adjusting?
Look at TSH levels:
<0.5 mlU/L = decrease dose
0.5-5 mlU/L = no change required
>5 mlU/L = increase the dose
Chest x-ray interpretation:
What does the acronym RIPE prompt you to check?
Rotation - is the distance between the spinous processes and the clavicles equal?
Inspiration - is there adequate inspiration? You should be able to see 5-6 anterior ribs or 8-10 posterior ribs
Projection - AP or PA? Remember you cannot comment on heart side on an AP film
Exposure - The left hemidiaphragm should be visible to the spine and the vertebrae should be visible behind the heart.
Chest x-ray interpretation:
What should you check under ‘A’?
A = airway
Is the trachea central?
Is the carina visible?
Can you see the left and right main bronchi
CXR Interpretation:
What should you check under ‘B’?
B = Breathing
LUNGS
Divide each lung into three zones
Compare left and right lung in each zone:
- Are lung markings present throughout?
- Is there any asymmetry?
- Are there any opacities?
PLEURA
- Fluid in the pleural space? (hydrothorax)
- Blood in the pleural space? (haemothoraz)
CXR Interpretation:
What should you check under ‘C’?
C = Circulation/cardiac
Heart size (no more than 50% of thoracic width)
CXR Interpretation:
What should you check under ‘D’?
D = diaphragm
Right slightly higher than left
Costophrenic angles - unclear/blunted angles can indicate fluid, consolidation or lung hyperinflation
Gastric bubble under left diaphragm
CXR interpretation:
What should you check under ‘everything else’?
Aortic knuckle
Bones
Tubes
Lines
Artificial valves
Pacemaker
ECG nodes
Sternotomy clips (loop like wire loops in the centre of the chest)
Interpreting ABGs:
Describe the 7 steps to interpreting an ABG
- Look at the PaO2:
- is it normal? (PaO2>10 kPa on room air, or ~10kPa less than the % inspired concentration FiO2 if receiving O2 therapy) - Look at the pH:
- <7.35 = acidotic
- >7.45 = alkalotic - Look at PaCO2:
High CO2 + low pH = respiratory acidosis
Low CO2 and high pH = respiratory alkalosis - Look at HCO3-
- low HCO3- and low pH = metabolic acidosis
- high HCO3- and high pH = metabolic alkalosis - Look for any compensation:
- Respiratory compensation = blowing off CO2 to increase pH, or retaining CO2 to decrease pH
- Metabolic compensation = kidneys increasing HCO3 to raise pH or decreasing HCO3 to decease pH
- Metabolic compensation takes at least a few days to develop - Look at the base excess
- >+2 = high HCO3-
- <-2 = low HCO3- - Check the anion gap:
Na+ - (Cl- +HCO3-)
Normal = ~4 to 12
4 causes of a high anion gap
- DKA
- Lactic acidosis
- Aspirin overdose
- Renal failure
4 features of digoxin toxicity:
- confusion
- nausea
- visual halos
- arrhythmias
Early, intermediate and late features of lithium toxicty:
Early: tremor
Intermediate: tiredness
Late: arrhythmias, seizures, coma, renal failure, diabetes insipidus
5 features of phenytoin toxicity:
- Gum hypertrophy
- Ataxia
- Nystagmus
- Peripheral neuropathy
- Teratogenicity
2 features of gentamicin toxicity:
Ototoxicity
Nephrotoxicity
2 features of vancomycin toxicity:
Ototoxicity
Nephrotoxicity
Managing over anti-coagulation in a patient who is not bleeding:
INR 5-8 = omit warfarin for 2 days then restart
INR >8 = omit warfarin and give 1-5mg PO vit K
Managing over anti-coagulation in a patient with minor bleeding:
INR 5-8 = omit warfarin and give 1-5 mg IV vit k
INR >8 = omit warfarin an give 1-5 mg vit k IV
Management of a STEMI (8)
- ABCDE
- O2 15L non-rebreather mask (only if hypoxic, do not give in COPD)
- Aspirin 300mg PO
- Morphine 5-10mg IV with cyclizine 50mg IV
- GTN spray/tablet
- Primary PCI (preferred) or thrombolysis
- Beta blocker 2.5mg PO unless asthmatic or LVF
- Transfer to CCU
Management of an NSTEMI (6)
BATMAN:
Beta-blocker unless CI
Aspirin 300mg stat dose PO
Ticagrelor 180mg PO (or clopidogrel 300mg PO)
Morphine 5-10mg IV with cyclizine 50mg IV
Anticoagulant - fondaparinux or LMWH
Nitrates
Give O2 if sats dropping
Management of acute left ventricular failure (8)
- ABCDE
- O2 15L non-rebreather mask (unless COPD)
- Sit patient up
- Morphine 5-10mg IV with cyclizine 50mg IV
- GTN spray/tablet
- Furosemide 40-80mg IV (repeat again as required/tolerated)
- If inadequate response, isosorbide dinitrate infusion +/- CPAP
- Transfer to CCU
What adverse features indicate unstable tachycardia? (4)
Tachycardia with:
- shock
- syncope
- MI
- Heart failure
How do you manage unstable tachycardia?
- Synchronized DC shock, up to 3 attempts
- Amiodarone 300mg IV over 10-20 mins and repeat shock; followed by:
- Amiodarone 900mg over 24 hrs
What constitutes a ‘narrow’ QRS?
<0.12 seconds (3 small squares)
How do you manage re-entry paroxysmal SVT?
What would this look like on ECG?
Monitor ECG continuously
1. Use vasovagal manoeuvres
2. Adenosine 6mg IV rapid bolus; if this is unsuccessful then give 12mg; if still unsuccessful give a further 12mg
3. If sinus rhythm is restored this was likely a re-rentry paroxysmal SVT
4. If the re-entry paroxysmal SVT recurs, give adenosine again and consider anti-arrhythmic prophylaxis
If sinus rhythm is NOT restored after step 2 - seek expert help! This could be atrial flutter and would require rate control e.g. beta-blocker
ECG: tachycardia, narrow QRS, regular
What drug is used to manage re-entry paroxysmal SVT?
Adenosine
Does re-entry paroxysmal SVT have a narrow or broad QRS?
Narrow (<0.12seconds/3 small squares)
How do you manage atrial fibrillation?
What would this look like on ECG?
Control rate with beta-blocker or diltiazem (CCB).
ECG: Tachycardia, narrow QRS, irregular, absent p waves, chaotic baseline
Which types of arrhythmia might cause an irregular tachycardia with a broad QRS? (2)
- Variants of AF (AF w/ BBB, pre-excited AF)
- Polymorphic VT
How do you manage tachycardia caused by AF with bundle branch block?
The same way you manage AF normally!
Control rate with beta-blocker or ditiazem.
Consider digoxin or amiodarone if evidence of heart failure.
How do you manage polymorphic VT/torsade de pointes?
Correct electrolyte imbalance
2g IV magnesium over 10 mins
Should spontaneously resolve - be prepared to shock if not (can develop into ventricular fib)
How do you manage ventricular tachycardia?
What does ventricular tachycardia look like on ECG?
Amiodarone 300mg IV over 20-60 mins; then 900mg over 24 hours
Regular tachycardia with broad QRS
How do you manage SVT with BBB?
Adenosine 6mg rapid bolus IV
Give 12mg if unsuccessful
Give a further 12mg if still unsuccessful
How do you treat ventricular tachycardia if the patient is stable?
Amiodarone: 300mg IV over 20-60 mins, then a further 900mg over 24 hours
Give 2 arrhythmias that might be treated with adenosine:
- Re-entry paroxysmal SVT
- SVT with BBB
(In both cases: 6mg rapid IV bolus, repeat with 12mg if successful, repeat with a further 12mg if still unsuccessful)
How do you manage anaphylaxis? (5)
REMOVE THE CAUSE ASAP!
1. ABCDE
2. 15L O2 non-rebreather mask
3. Adrenaline 500 micorgrams of 1:1000 IM (repeat if no improvement after 5 mins)
4. Chlorphenamine 10mg IV (antihistamine is only given once patient is stable)
5. Hydrocortisone 200mg IV
NB:
Treat wheeze if asthmatic
Amend drug allergies box!
Mx of an acute asthma exacerbation:
Oh SHIT Me
1. Oxygen
2. Salbutamol 5mg neb
3. Hydrocortisone 100mg IV if severe/life-threatening or predisolone 40-50mg PO if moderate
4. Ipratropium 500 micrograms neb
5. Theophyline or aminophylline if life threatening
6. Magnesium sulphate
How do you treat an acute exacerbation of COPD?
Same as asthma exacerbation - Oh SHIT Me, add abx if infective exacerbation
AND be cautious with high flow O2!
A very sick patient (peri-arrest) has known COPD - should you give o2?
Yes - give high flow o2 and review quickly after with an ABG
Hypoxia kills quicker than hyprecapnia!
If a patient with COPD is hypoxic but NOT peri-arrest, how should you start O2 therapy?
Start with 28% O2 and do an ABG 30 mins later to assess the effect
How do you treat a pneumothorax secondary to lung disease?
Chest drain if >2cm or patient has SOB or if patient is >50 years old
Otherwise aspirate
How do you treat a primary spontaneous pneumothorax?
If <2cm rim and not SOB discharge and follow-up in 4 weeks
If >2cm rim or SOB aspirate (up to 2 attempts, then try chest drain)
What is the CRB-65 score?
Used to decide on tx of pneumonia:
C - confusion
R - resp rate ≥ 30
B - systolic BP <90
65 - 65 years or older
One point for each
What tx would a CRB-65 score of 1-2 indicate?
Low risk - give 500mg amoxicillin TDS PO for 5 days
What tx would a CRB-65 score of 3-4 indicate?
High risk - consider admitting anyone with a score of 2 or more
How do you manage a PE?
- High flow O2
- Analgesia: morphine 5-10 mg IV with cyclizine 50mg IV
- Anticoagulation for at least three months: apixiban, rivaroxaban (can be used in renal impairment), (LMWH can be used in renal failure)
- If low BP; give IV fluid bolus and contact ITU and consider thrombolysis
What does class IV haemorrhagic shock consist of? (7)
Blood loss >2000ml
Blood loss >40%
Heart rate >140bpm
Blood pressure decreased
Resp rate >40
Urine output <5ml/hr
Confused/unresponsive
How do you manage an acute upper GI bleed? (9)
- ABC and O2
- Cannulas: two large bore
- Catheter: monitor strict fluid balance, aim for >30mls/hr urine output
- Crystalloid fluid: 500ml hartmann’s or normal saline bolus over 15 mins (250ml if increased risk of overload e.g. HF)
- Cross-match 6 units and coagulation screen
- Correct clotting abnormalities:
- if platelets <50 x10^9/L give platelet transfusion
- if PT/aPTT more than 1.5 times normal give fresh frozen plasma - Camera: endoscopy should be performed on all unstable patients with severe UGIB immediately after resus, within 24 hours
- Culprit drugs: stop NSAIDs, warfarin, heparin, aspirin (if bleed was due to warfarin give prothrombin complex!)
- Senior help/surgeons!
What is Supraventricular Tachycardia?
In normal circumstances, electrical impulses are transmitted from the SA node to the AV node. The AV node causes a delay to allow the ventricles to fill completely before contracting. This maintains the normal heart rate.
In SVT an abnormal electrical pathway originating from above the ventricles (i.e. in the atria) bypasses the AV node, accelerating the heart rate and causing ventricles to contract before they’re completely full.
What is re-entry SVT?
The AV nodal tissue has two pathways that form a circle.
An impulse will get stuck going round and round this circuit very fast and emitting depolarizing impulses to the rest of the myocardium.
4 differentials for a narrow QRS complex tachycardia:
- Sinus tachycardia
- Supraventricular tachycardia
- Atrial fibrillation
- Atrial flutter
How do you differentiate between the 4 types of narrow QRS complex tachycardia?
Sinus tachy: normal PQRS formation
SVT: regular rhythm
Atrial fib: irregularly irregular
Atrial flutter: atrial rate of ~300 bpm gives ‘sawtooth’ baseline
Management of a seizure: (7)
- ABC
- Recovery position and O2
- Lorazepam 2-4mg IV or diazepam 10mg IV or midazolam 10mg IV
- Repeat dose if still fitting in after 5 mins
- Inform anaesthetist
- If still fitting after a further 5 mins give Phenytoin 15-20 mg/kg IV
- If still fitting after another 5 mins give propofol and intubate and ventilate
Management of a stroke: (5)
- ABC
- Head CT to exclude haemorrhage
- If onset <4.5 hours ago -> thrombolysis
- Aspirin 300mg
- Transfer to stroke unit
Diagnostic criteria for DKA:
Blood glucose >11mmol/l or known diabetes
Ketones >3 mmol/L or +2 on urine dipstick
pH <7.3 or HCO3- <-15
Mx of DKA: (4)
- ABCDE
- IV saline (initially 1L over an hour, then continue at a slower rate)
- Fixed rate insulin infusion (0.1 unit/kg/hr)
- Monitor continuously (frequent VBGs), should improve within 6-24 hours
Treatment targets for DKA: (4)
- Decrease in ketones by 0.5 mmol/L/hr
- Increase in HCO3- by 3mmol/L/hr
- Decrease in CBG by 3mmol/L/hr
- Maintain K+ at 4-5.5 mmol/L
3 possible complications of DKA:
- HypoK leading to VT
- Cerebral oedema
- High risk of thrombosis/DVT
Diagnostic criteria for hyperosmolar hyperglycaemic state:
Hyperosmolarity >320mmol/L
Hyperglycaemia >30mmol/L
No/low ketones <3mmol/L
No acidosis pH>7.3
Hypovolaemia