AIP Flashcards
What is alveolar-arterial O2 gradient used for
In type 2 resp failure
- if A-a gradient normal = not due to lung disease
- if A-a gradient is raised = intrinsic lung disease
causes of a complete white out on CXR
Trachea deviated towards = total lung collapse, pneumonectomy
Trachea central = consolidation (pneumonia), ARDS
Tracheal away = large pleural effusion
Electrolyte daily requirements
Na - 1-2 mmol/kg/24hr
Cl - 1 mmol/kg/24hr
K - 0.5-1 mmol/kg/24hr (max safe dose is 10mmol/hr)
(1 of each)
Glucose - 50-100g
Water - 25-30 ml/kg/24hr (20-25 if elderly, HF or CKD)
When doing maintenance fluids for obese patients - use ideal bodyweight based on BMI and use lower end of range e.g. 25 ml/kg/24hr
Signs of dehydration on U&E
Hypernatraemia, high haematocrit, raised Hb
Transfusion threshold - normally and with ACS
70g/L normally
80g/L with ACS
G&S vs crossmatch
G&S - just looks at patients blood - identifies Rhesus status, ABO blood group and antibodies present
- no blood is issued
- used if no current blood loss, anticipate might be needed in future
Crossmatch - assesses transfusion by mixing small amount of patient and donor blood to look for a reaction
- following testing blood is issued
- need a G&S before hand
Blood product thresholds
Platelets - bleeding and <30x10^9
Plasma - if bleeding and abnormal coag (APPT ratio >1.5)
Cryoprecipitate - DIC with fibrinogen < 1g/L, von willebrand
Immediate immune reactions to transfusion, how they present and management
ABO incompatibility - fever, tachycardia, hypotension, anxiety, may have red urine. Treat by stopping transfusion, starting IV fluids and giving platelets/ other blood products as needed to prevent DIC.
TRALI - transfusion related acute lung injury - present with fever, SOB, hypoxaemia, hypotension. Diffuse infiltrates on CXR. Stop transfusion, give O2, IV fluids and ionotropes (dobutamine or adrenaline)
Anaphylaxis - itchy rash, angioedema, SOB, vomiting, light headed, hypotension. Stop transfusion, IM adrenaline 0.5mg every 10 mins, salbutamol nebs, O2. Steroids, chloramphenamine 2nd line/ post initial stabilisation.
Not a reaction but can get fluid overload causing SOB, bibasal creps, hypoxia, tachycardia, raised JVP. Treat with IV furosemide and O2.
Indications for arterial line + what the trace tells us + complications
Continuous real time monitoring of BP, need for repeat ABG’s
Tells us:
- blood pressure
- myocardial contractility - gradient of upwards curve
- volume status - narrow waveform = hypovolaemia
Complications:
- bleed - apply 3-5 mins of pressure post removal
- thrombus
- emboli
- infection
- accidental drug injection
Causes of raised and low CVP - how it is measured?
High - fluid overload, RHF, pulmonary hypertension, tricuspid disease, SVC obstruction
Low - hypovolaemia, distributive shock
Measured using central venous catheter e.g. central line, Hickmann, picc line
Catecholamine drugs used in ICU - what are their target receptor and action
Noradrenaline - Acts on alpha 1 - cause peripheral vasoconstriction increasing SVR and CO
Adrenaline - Acts on alpha 1 (high doses) doing same as above and acts on Beta 1 (low doses) causing increased SV, HR, CO
Dopamine - same as adrenaline
Dobutamine - Acts on Beta 1 and Beta 2 - causes increased HR, SV, CO but causes vasodilation
Classes of anti-arrhythmics
Class I - sodium channel blocker e.g. lidocaine, phenytoin, quinidine, flecainide
Class II - Beta blocker e.g. propanalol
Class III - K+ channel blocker e.g. amiodarone
Class IV - calcium channel blocker e.g. verapamil, diltiazem
Indications for NG tube + when to do a PEG tube
Feeding
- dysphagia or unsafe swallow due to neuro issue
- reduced consciousness
- protect stomach after surgery
- insufficient oral intake
Removal of gastric contents
- bowel obstruction for immediate decompression
- For resting of the bowel in bowel obstruction
Do a PEG tube when need long term feeding e.g.
- burns
- oesophageal carcinoma
- coma, stroke
- Crohn’s
- fistulae
How is TPN given
Via a central line
Refeeding syndrome
Malnutritioned patients get energy by breaking down existing tissues, hence have low vitamin, electrolyte levels
Occurs when high amount of carbohydrates are given to a malnourished patient. Causes for high insulin secretion,
Insulin leads to K+, PO4, Mg movement into cells, causing a significant drop in levels and an increased extracellular fluid volume
Get an increase in O2 demand leading to increased cardio and respiratory effort
Can cause rhabdomyolysis, cardiac/resp failure, seizure, coma
what to give patients in a coma
glucose, thiamine IV if cause unclear
may also trial naloxone or flumazenil
raised ICP consider mannitol
fluids + ventilation, nutrition, pressure sores
How to confirm brainstem death
First need to meet two criteria
- evidence that condition due to irreversible structural brain damage
- all reversible causes of coma excluded
Then:
- Pupils fixed and unresponsive to bright light
- Absent corneal reflexes
- Absent vestibulo-ocular reflexes (irrigation of the ear with ice-cold water, dolls eye reflex)
- No motor response to trigeminal pain response. An example of this would be no facial grimace to nail bed pressure
- No gag or cough reflex
- Apnoea
What number to call if no signs of life in suspected cardiac arrest
2222
When to give adrenaline/amiodarone during CPR
Give 1mg IV adrenaline and amiodarone 300mg IV after 3rd shock. Then give adrenaline every 3-5 minutes after
Give an additional 150mg amiodarone after 5 shocks
If not shockable give 1mg IV adrenaline as soon as IV access
Reversible causes of cardiac arrest to treat during CPR
4 H’s
- Hypoxia
- Hypovolaemia
- Hypothermia
- Hyper or hypokalaemia
4 T’s
- Tension pneumothorax
- Tamponade
- Toxins
- Thromboembolism
Cardiogenic shock - definition, causes, presentation, ix, mx
Caused by failure of heart to achieve required cardiac output
Causes include: HF, MI, acute dysrhythmia, acute mitral regurg, cardiomyopathy, thyrotoxicosis, severe valvular disease
Defined as SBP <90 for >30 mins or poor peripheral/ end organ perfusion (<0.5ml/kg/hr urine output)
Present as pale, mottled, cold skin. Prolonged CRT. Cold peripheries. Tachycardia, hypotension. Often pulmonary oedema, raised JVP (signs of HF)
Ix: bloods (U&E for renal failure, FBC for anaemia, LFT), ABG, BNP (low can help rule out), ECG, Echo, cardiac enzymes (trops)
Another cause is obstructive e.g. PE, tension pneumothorax, tamponade - do CXR, CTPA
Mx:
O2 to maintain sats >94% (check vs 96%)
250ml fluid boluses if intravascular volume depletion
Monitor with - cardiac monitoring, BP via central line, CVP via central line, catheter for urine output
Treat cause e.g. thrombolysis, percutaneous intervention for MI
vasopressors - dobutamine
Intra-aortic balloon pump - increases cardiac output and improves coronary artery blood flow
Hypovolaemic shock
Presents with dizziness, fainting, cold/clammy/confused. Skin pale, sweaty. Prolonged CRT, hypotension, tachycardia.
Causes include blood loss, burns, excessive exercise, diarrhoea and vomiting
Ix: AtoE Bloods - Hb, U&E, FBC, LFT, Coag, crossmatch, G&S ABG Urine output US can differentiate from cardiogenic CVP monitoring
Mx: AtoE Look for cause - try to stop bleeding Oxygen - keep sats 94 Fluid boluses - 500ml over 15 mins Blood as needed IV pain relief Tranexamic acid If non responsive to fluids may consider vasopressors
If needed:
Resuscitative endovascular balloon occlusion of the aorta
Surgery to stop bleeding
anaphylactic shock
Present with SOB, angioedema, urticaria, itching
serum mast cell tryptase - use to confirm diagnosis
Mx:
2222
Lie flat with legs raised, secure airway, give O2
0.5mg IM adrenaline - repeat after 5 mins if no improvement
Fluid challenge - 500ml over 5-20 mins
Chlorphenamine 10mg, hydrocortisone 200mg after initial resus
further deterioration treat as acute asthma
observe for 6-12 hours
Neurogenic shock - cause, triad of signs and mx
Cause is cervical and upper thoracic injury (above T6)
Loss of sympathetic tone that causes vasodilation and bradycardia
Can also be caused by iatrogenic spinal anaesthesia placement
Develop triad of bradycardia, hypotension and hypothermia
Mx:
IV fluids
Treat cause
Atropine if haemodynamically significant bradycardia
Vasopressors e.g. dopamine, dobutamine may be needed if fluid resus not effective