Chapter 12 Resuscitation in special circumstances Flashcards
In acidosis, does serum potassium increase or decreases?
Increase as H+ ions are shifted intracellularly in exchange for K+
At what level is hyperkalaemia considered severe?
> 6.5 mmol/L
What drugs can cause hyperkalaemia?
ACE-I Angiotensin II receptor antagonist Potassium sparing diuretics (spironolactone) NSAIDs Beta-blockers Trimethoprim
What endocrine condition can cause hyperkalaemia?
Addison’s disease (adrenal insufficiency)
In what conditions/diseases is potassium release from tissues of the body?
Rhabdomyolysis
Tumour lysis
Haemolysis
Burns
What are symptoms of hyperkalaemia?
Weakness
Flaccid paralysis
Paraesthesias
Depressed deep tendon reflexes
What ECG changes are seen in hyperkalaemia?
Tall, peaked T waves (T wave larger than R wave in more than one lead) Shortening of QT interval 1st degree heart block Bradycardia ST segment depression Flattened or absent p waves Widened QRS S and T wave merging (sine wave pattern) Ventricular tachycardia Cardiac arrest (PEA, VF/ VT, asystole)
When treating a patient for hyperkalaemia with an insulin infusion, how long after the infusion stops is the patient at risk of hypoglycaemia?
Usually 3 hours but can be up to 6 hours
What medication should you give along with resonium A to avoid complications of this medication?
Laxative
Does a K+ level of 5.5 to 5.9 mmol/L need treatment?
Usually not.
Address underlying cause of hyperkalaemia (drugs/diet) and avoid further rise.
If it does need to be treated, give:
Resonium A 15 -30g orally or a retention enema, onset < 4 hours.
Consider IV fluids
Does K+ level 6.0 to 6.4mmol/L need treatment?
Yes Shift intracellularly with: 10 units novorapid 25 g glucose (50ml 50% glucose) IV over 15 - 30 minutes Duration of action 4 - 6 hours Remove potassium from the body (resonium, dialysis)
What dose of nebulised salbutamol would you give for hyperkalaemia? How long will it last?
10 - 20 mg nebulised. Onset 15 minutes, duration 4 - 6 hours
What dose of insulin and glucose will you give for hyperkalaemia? How long does it last?
10 units novorapid, 50ml 50% glucose (25g) over 30 minutes
Onset 15 - 30 minutes, duration 4 -6 hours
If the patient is acidotic and has hyperkalaemia, what treatment could you consider?
50ml 8.4% sodium bicarbonate = 50mmol
How many mmol of calcium in 10ml of 10% calcium chloride and 10ml 10% calcium gluconate
Calcium chloride = 6.8mmol
Calcium gluconate = 2.2 mmol
What steps do you take when a patient arrest DURING haemodialysis?
1) Assign a nurse to dialysis machine
2) STOP ultrafiltation (fluid removal)
3) Give a fluid bolus
4) Return patients blood
5) Disconnect from dialysis machine (most machines recommend this before giving any shocks)
6) Leave dialysis access open and use for drug administration
7) Now treat as you would for all patients, however most likely cause is hyperkalaemia/VT/VF
At what level is hypokalaemia severe?
< 2.5mmol/L
What are the possible causes of hypokalaemia?
GIT: diarrhoea Drugs: diuretics, laxatives, steroids Renal losses: renal tubular disorders, diabetic insipidus, dialysis Endoncrine: cushings syndrome, hyperaldosteronsim Metabolic alkalosis Magnesium depletion Poor dietary intake Treatment of hyperkalaemia
What are the signs and symptoms of hypokalaemia?
Nerves and muscles affected: Fatigue Weakness Leg cramps Constipation If severe (< 2.5mmol/L): rhabdomyolysis, ascending paralysis, respiratory difficulties
What are the ECG features of hypokalaemia?
U waves T wave flattening ST segment changes Arrhythmias (including AF, especially if patient is on digoxin) Cardiac arrest (VF/pVT, PEA, asystole)
What is the maximum IV dose of K+ and the fastest rate you can give it for an unstable arrhythmia when cardiac arrest is imminent?
20 mmol over 10 minutes = 2 mmol/min
followed by 10mmol magnesium
What is the maximum recommended rate of K+ replacement IV ?
critically low K+ but stable
20 mmol/hour
What dose of K+ do you give for a cardiac arrest due to hypokalaemia?
5mmol bolus followed by 10mmol magnesium
What monitoring is needed when giving IV potassium?
Telemetry
What are the causes of hypercalaemia? (Ca2+ > 2.6mmol/L)
Primary or tertiary hypeparathyroidism
Malignancy
Sarcoidosis
Drugs
How does hypercalcaemia present?
Confusion Weakness Abdominal pain Arrhythmias Cardiac arrest
What are the ECG features of hypercalcaemia?
Short QT interval Prolonged QRS Flat T waves AV block Cardiac arrest
What is the treatment of hypercalcaemia?
IV fluid replacement Frusemide 40mg IV Hydrocortisone 200mg IV Pamidronate 30 - 90mg IV Treat underlying cause
What are the causes of hypocalcaemia? ( <2.1 mmol/L)
Chronic renal failure Acute pancreatitis Calcium channel blocker overdose Toxic shock syndrome Rhabdomyolysis Tumour lysis syndrome
What are the symptoms of hypocalcaemia?
Paraesthesias Tetany Seizures AV block Cardiac arrest
What are the ECG features of hypocalcaemia?
Prolongs QT interval
T wave inversion
Heart block
Cardiac arrest
What are the causes of hypermagnaemia?
Renal failure
Iatrogenic
What are the symptoms of hypermagnaesaemia?
Confusion Weakness Respiratory distress AV block Cardiac arrest
What are the ECG findings of hypermagnaesaemia?
Prolonged PR and QT interval
T wave peaking
AV block
Cardiac arrest
How do you treat hypermagnaesaemia?
Consider if > 1.75 and symptomatic
Calcium chloride 10% 5 - 10ml IV repeated as necessary
Saline diuresis: normal saline + frusemide
IV haemodialysis if ventilatory support needed
What are the cause of hypomagnasaemia?
GI losses Polyuria Starvation Alcoholism Malabsorption
What are the symptoms of hypomagnasaemia?
Tremor Ataxia Nystagmus Seizures Arrhythmias - torsades de pointes Cardiac arrest
What are the ECG findings of hypomagnesaemia?
Prolonged PR and QT interval ST segment depression T wave inversion Flattened p waves Increased QRS duration Torsades de pointes
How much and how quickly can you replace magnesium in unstable patient (torsades de pointes, seizures)
2g or 10 mmol over 10 minutes
When a patient has progressed to septic shock ( lactate > 4 mmol/L or hypotension unresponsive to fluids), what is the mortality rate?
50%
Is there much evidence supporting improved clinical outcomes when activated charcoal is used for overdoses?
No, but may still be beneficial in large overdoses.
Use up to 2 hours post overdose, effectiveness decreases over time
What is the dose of intralipid for local anaesthetic overdose?
20% intralipid 1.5ml/kg as bolus (=100ml in 70kg adult)
bolus can be repeated 1-2 times in cardiac arrest at 5 min intervals
then, 0.25ml/kg/min for 30 - 60 minutes (about 600ml over 30 minutes in 70kg adult)
Can double infusion rate if BP declines
What routes can naloxone be given?
Intranasal, subcut, IM, IV
dose range 100mcg up to 800mcg
Duration of action 45 - 70 minutes
What is the risk of rapid reversal of opioids in a patient who is opioid dependent?
Acute withdrawal syndrome, sympathetic surger:
Behavioural disturbance/severe agitation
Acute pulmonary oedema
Ventricular arrhythmia
What is the risk of giving flumazenil to a patient that is dependent on benzodiazapines, epileptic, or co-ingestion with tricyclic antidepressent?
Withdrawal syndrome
Seizure
Arrhythmias
Hypotension
Would you give naloxine or flumazenil to a patient suspected over overdose who has has a cardiac arrest?
No, just follow usual protocol
What pH would you try to target/stop giving sodium bicarbonate in a TCA overdose?
pH 7.44 to 7.55
Increases protein binding and increases sodium load
What dose of atropine would you give for organophosphate, carbamate or nerve agent poisoning?
Large dose 2-4mg bolus IV
In anaphylaxis, what % of patients may not exhibit a skin reaction?
10 - 20%
Why is adrenaline so well suited for treating anaphylaxis?
Alpha receptor agonist: treats vasodilation
Beta 1 agonist: increased myocardial contractility
Beta 2 agonist: treats broncospasm
Suppressed histamine and leukotriene release
How many IM doses of 0.5mg 1:1000 adrenaline do you give before giving IV infusion?
2 or 3 (ideally rotate sites)
A patient has anaphylaxis treated with IM adrenaline but has ongoing
a) Stidor
b) Wheeze
How would you treat a) compared to b) ?
a) nebulised adrenaline (5ml of 1:1000)
b) nebulised salbutamol
How common are biphasic reactions in anaphyalxis?
3 - 20%
Monitor for 4 hours post LAST dose of adrenaline
What dose of corticosteroid do you give for anaphylaxis?
prednisone 50mg PO
hydrocoritsone 200mg IV