Chapter 12: Resuscitation in Special Circumstances Flashcards
What happens to potassium in acidosis?
Serum K+ increase as it moves from cells to serum
H+/K+ pump
How is hyperkalaemia defined and what classifies as severe?
K+>5.5mmol/L
Severe >6.5mmol/L
What can cause hyperkalaemia?
Renal failure
Acidosis
DKA
Drugs - Spironolactone, ACEi, amiloride, ARB, NSAID’s, B blockers, trimethoprim
Endocrine - Addison’s disease
Tissue breakdown - rhabdomyolysis, TLS, haemolysis
What ECG changes do you see with hyperkalaemia?
Absent/small p waves Long PR Tall tented t waves Wide QRS Can see ST segment depression
S and T merging
VT
Bradycardia
Cardiac arrest
How is hyperkalaemia treated?
STOP DRUGS/K+ fluids
- IV Calcium chloride - 10ml/10% over 2-5 mins
- Insulin/Dextrose - 10 units in 250ml of 10% 15-30min
- Sodium bicarbonate - 50mmol IV bolus - severe acidosis or renal failure
- Salbutamol nebulised 10-20mg
- Dialysis
- K+ binder - calcium resonium 15-30g or Sodium Polystyrene Sulfonate
What do you do for each stage of hyperkalaemia?
Mild: 5.5-5.9
- Address cause
- Calcium resonium (bind to calcium)
Mod: 6.0-6.4
- Insulin dextrose infusion
- Address cause
- Calcium resonium
Severe: 6.5+
- Expert help
- Calcium gluconate
- Insulin dextrose infusion
- Address cause
- Salbutamol nebulisers back to back
- Calcium resonium
- Remove K+ - dialysis
To give calcium gluconatecalcium chloride if ECG changes.
Repeat ECGs
What are the main risks associated with hyperkalaemia treatment?
Hypoglycaemia - monitor BM
Tissue necrosis - secondary to extravasation of intravenous calcium salts - Ensure secure vascular access
Intestinal necrosis and obstruction - K+ exchange resin - avoid prolonged use and give laxative
Rebound hyperkalaemia - after drug treatment warn off - monitor for at least 24hr
How is hypokalaemia defined?
<3.5mmol/L
Severe = <2.5mmol/L
What can cause hypokalaemia?
GI losses Alkalosis Drugs - loop diuretics, thiazides, laxatives, steroids Renal losses Cushings/hyperaldosteronism Mg depletion Poor intake
Overtreated High K+
How can you recognise hypokalaemia?
- Rule out in all arrhythmia/cardiac arrest
- Seen at end of haemodialysis or in peritoneal dialysis
Symptoms: - Fatigue
- Weakness
- Leg cramps
- Constipation
If severe:
- Rhabdomyolysis
- Ascending paralysis
- Resp difficulties
What ECG features are seen in hypokalaemia?
U waves Small t waves Tall P waves ST segment changes Arrhythmia's Cardiac arrest
How should K+ be replaced?
Gradually
Max 10mmol/L per hour on normal ward
Ma 20mmol/L per hour in HDU/ICU
More rapid infusion indicated in unstable arrhythmia - 2mmol/L/min for 10 mins then 10mmol over 5-10 mins
What can cause hypercalcaemia? (>2.6mmol/l)
Primary/tertiary hyperparathyroid
Malignancy
Sarcoid
Drugs
How does hypercalcaemia present?
Confusion Weakness Abdo pain Hypotension Arrhythmia Cardiac arrest
What ECG changes are seen in hypercalcaemia?
Short QT Wide QRS Flat t waves AV block Cardiac arrest
How is hypercalcaemia treated?
Fluid replacement Furosemide - 1mg/kg Hydrocortisone 200-300mg Pamidronate 30-90mg/ bisphosphonates Treat underlying cause
What can cause hypocalcaemia? (<2.1mmol/l)
Chronic renal failure Pancreatitis Calcium channel blocker OD Toxic shock syndrome Rhabdomyolysis TLS
How does hypocalcaemia present?
Paraesthesia Tetany Seizures AV block Cardiac arrest
What ECG changes are seen for hypocalcaemia?
Prolonged QT
T wave inversion
Heart block
Cardiac arrest
What can cause hypermagnasaemia? (>1.1mmol/l)
Renal failure
Iatrogenic
How does hypermagnasaemia present?
Confusion Weakness Resp. depression AV block Cardiac arrest
What ECG changes are seen for hypermagnasaemia?
Prolong PR and QT
T wave peak
AV block
Cardiac arrest
How is hypermagnasaemia managed?
Calcium chloride 10ml 10%
Ventilatory support if req.
Saline diuresis - furosemide 1mg/kg+0.9% saline
Haemodialysis
What can cause hypomagnasaemia? (<0.6mmol/l)
GI loss Polyuria Starvation Alcohol Malabsorption
How does hypomagnasaemia present?
Tremor Ataxia Nystagmus Seizures Arrhythmia - torsades Cardiac arrest
How does hypomagnasaemia present on ECG?
Prolong PR and QT ST depression T wave inversion Flat p waves Wide QRS Can get polymorphic VT - torsades
How is hypomagnasaemia managed?
2g 50% MgSo4 (4ml 8mmol/L)
- mild = oral replacement (0.5-0.8)
- severe = over 15 mins
- torsades = over 1/2 mins
- Seizure = over 10 mins
How to manage sepsis
Sepsis 6 -
02, Blood cultures, lactate, Abx, fluids, urine output
What specific treatments are available for poisoning?
Skin exposure - remove clothes
Activated charcoal - <1hr and intact airway
Whole bowel irrigation using polyethylene glycol
Sodium Bicarb IV - salicylate poisoning and amitriptyline
Haemodialysis
Specific antidotes
What is the specific antidote for paracetamol?
N-acetylcysteine
What is the specific antidote for organophosphate poisoning?
High dose atropine
What is the antidote for cyanides poisoning?
Sodium nitrite
Hydroxocobalamin
Amyl nitrite
What is the antidote for digoxin poisoning?
Digibind - digoxin specific Fab antibodies
What is the antidote for benzodiazepines?
Flumazenil if no risk of seizure
What is the antidote for opioid poisoning?
Naloxone 400mcg IV, 800mcg IM, 800mcg SC or 2mg Intranasal
Non IV may be quicker - save time getting access
Duration of action not as long as respiratory depression persist - give increments until breathing adequately
Can give naloxone infusion
What does opioid poisoning cause?
Resp depression
Pinpoint pupils
Coma following resp. arrest
What happens if opioids are withdrawn acutely in poisoning?
State of sympathetic excess leading to complications:
- Pulmonary oedema
- Ventricular arrhythmia
- Severe agitation
Use naloxone cautiously in patients with dependence
What can a benzodiazepine OD cause?
Loss of consciousness
Respiratory depression
Hypotension
What can reversal of benzodiazepine OD with flumazenil lead to in patients with dependence or have coinjested pro-convulsants?
Seizure
Arrhythmia
Hypotension
Withdrawal syndrome
Is flumazenil used in comatose patients?
No
What can tricyclic antidepressant OD cause?
Hypotension
Seizure
Coma
Life-threatening arrhythmia - commonly shockable
Anti-cholinergic effects - mydriasis, fever, dry skin, delirium, tachycardia, ileus, retention
What may indicate that a TCA overdose will lead to arrhythmia?
Wide QRS
Right axis deviation
Usually noted with prolonged QT
Consider sodium bicarb
When can you get local anaesthetic toxicity?
Regional anaesthesia - enters artery or vein
What issues can you get with local anaesthetic toxicity?
Severe agitation
Loss of consciousness with or without tonic-clonic convulsions
Sinus Bradycardia/ Conduction blocks/Asystole/VT
How can local anaesthetic toxicity be treated?
Resus measures
IV 20% lipid emulsion
- initial 1.5mL/kg/hr bolus in 1 min followed by 15mL/kg/hr infusion
- Give upto 3 boluses at 5 min intervals
- Max 12mL/kg emulsion
What can cocaine toxicity cause?
Sympathetic overstimulation:
- agitation
- symptomatic tachycardia
- hyperthermia
- hypertensive crisis
- myocardial ischaemia with angina
What can be done to treat cocaine toxicity?
Small dose IV benzo (midazolam, diazepam, lorazepam)
GTN and phentolamine - reverse coronary vasoconstriction
Can consider beta blockers and anti-arrhythmics - best unclear
Use normal adrenaline dose if arrest
How is drug induced severe bradycardia managed?
Atropine - organophosphate, carbamate, nerve agent poisoning or acetylcholinesterase inhibitors
2-4mg IV repeated doses
What can be used to treat bradycardia due to beta blockers or calcium channel blockers?
Can use Isoprenaline at high dose if refractory bradycardia due to beta blockers
Vasopressors, inotropes, calcium, glucagon, phosphodiesterase inhibitors and high dose insulin-dextrose-potassium infusions
What can cause cardiorespiratory arrest in asthmatic patients?
- Severe bronchospasm and mucous plugging –> asphyxia
- Hypoxia –> cardiac arrhythmia. Can also be due to drugs or electrolyte abnormalities
- Dynamic hyperinflation in mechanically ventilated - reduced venous return and BP
- Tension pneumothorax
What signs indicate acute severe asthma?
- PEFR 33-50%
- RR >25
- HR >110
- Inability to complete sentence in 1 breath
What signs indicate life-threatening asthma?
Altered conscious level Exhaustion Arrhythmia Hypotension Cyanosis Silent chest Poor resp effort
PEFR<33
SpO2 <92%
PaO2 <8kPa
‘normal’ PaCO2 - 4.6-6
What indicates asthma mat be near fatal?
Raised PaCO2 and/or mechanical ventilation with raised inflation pressures
What may absence of wheezing in asthma indicate?
Critical airway obstruction
Increased wheezing may indicate + response to therapy
What can happen to SpO2 in SABA therapy of asthma?
May initially decrease as beta agonists cause bronchodilation and vasodilation - increased intra pulmonary shunting
How can acute asthma attacks be managed?
- High flow O2 - sats of 94-98%
- Salbutamol 5mg neb - repeat every 15-30 mins or cont. 5-10mg/hr
- Add neb ipratropium bromide 500mcg 4-6hr
- Prednisolone 40-50mg PO or hydrocortisone 100mg IV
Can give IV Magnesium sulphate 2g (8mmol) over 20 mins
Consider IV salbutamol 250mcg if inhaled not possible
Senior advice for aminophylline - 5mg/hr IV 20 min then 500-700mcg/kg/hr infusion (max dose 20mcg/mL to avoid toxicity)
What can beta agonist and steroid therapy in asthma cause?
Hypokalaemia
When should tracheal intubation and controlled ventilation be considered in asthma?
Deteriorating peak flow Reduced conscious level Persisting/worsening hypoxaemia Worsening resp. acidosis Severe agitation, confusion and fighting against o2 mask Progressive exhaustion Cardioresp. arrest
Role of non invasive ventilation unclear - only considered in ICU setting
Which 3 criteria are indicative of anaphylaxis?
1 Sudden onset and rapid progression of symptoms
2 Life threatening airway and/or breathing and/or circulatory problems
3 Skin and/or mucosal changes - flushing, urticaria, angioedema
What is important to remember about recognising anaphylaxis?
Skin and mucosal changes alone not a sign
Skin and mucosal changes can be subtle/absent
Can be GI symptoms - abdo pain as blood and fluid redirected away from gut
How is anaphylaxis managed in an adult?
Remove trigger Lie down + legs up IV Fluid challenge 500-1000ml IV chlorphenamine 10mg IV hydrocortisone 200mg IM Adrenaline 0.5mg (0.5ml of 1:1000) - anterolateral middle thigh - repeat at 5min mark if no response with fluid bolus
When can IV adrenaline be used in anaphylaxis?
Only by specialists
Can cause hypertension, tachycardia, ischaemia, arrhythmia if spontaneous circulation
May be used if repeated IM doses
Max 50mcg in adults and 1mcg/kg in children
How can anaphylaxis be investigated?
Mast cell tryptase - 3 timed samples:
- ASAP after resus
- 1-2hr after start of symptoms
- 24hr after
How is haemorrhage in pregnancy managed in cardiac arrest?
Fluid Resus
Tranexamic acid and correct coagulopathies
Oxytocin, ergometrine, prostaglandins and uterine massage for uterine atony
Uterine compression sutures, packs or intrauterine balloon devices
Surfical control - aortic cross clamp/compression and hysterectomy. Placenta percreta may req. intra-pelvic surgery
How is pre-eclampsia treated?
Magnesium sulphate - prevent eclampsia in labour
How are amniotic fluid emboli managed?
Supportive
Correct coagulopathies
What are the key causes of cardiac arrest in trauma patients?
Severe traumatic brain injury Hypovolaemia Hypoxia Tension pneumothorax Direct injury to vital organs Cardiac tamponade
What is a key focus of traumatic cardiac arrest management? What may be helpful to use in these cases?
Correct the reversible causes
Do chest compressions but unlikely to be successful without correction
FAST scan or CT may be useful in guiding treatment
Early tracheal intubation can be beneficial
What can happen if positive pressure ventilation is used in low cardiac output conditions?
Further circulatory depression by impeding venous return
How are tension pneumathoraces managed in traumatic cardiac arrest?
Needle decompression - 2nd intercostal space midclavicular line
How is a cardiac tamponade managed?
Resuscitative clamshell thoracotomy
Needle aspiration unreliable - pericardium commonly full of clotted blood
When should resuscitative thoracotomies be considered?
Penetrating torso trauma and <15min CPR
Blunt trauma and <10min prehospital CPR
No pulse after penetrating chest or cardiac injuries and signs of life or ECG activity
What are the commonest causes of anaesthesia related cardiac arrest?
Airway management
What are the most common rhythms seen in peri op cardiac arrest?
Asystole - 41%
VF - 35%
What is drowning and what are the “types”?
Respiratory impairment from submersion/immersion in liquid
Submersion - face underwater/covered by water
Immersion - head remain above water - e.g. life jacket
What typically happens to patients who are immersed in water?
Become hypothermic
Airway remain patient
Water splashes can cause aspiration
What happens in submersion?
Patient initially hold breath and swallow water
As pt. become hypoxic and hypercapnic, breath holding reflex and laryngospasm reflex lost. Patient aspirate water
Laryngospasm reflex prevent water entering lungs
Bradycardia due to hypoxia occur before sustaining cardiac arrest
How do you attempt to rescue someone from the water?
Ideally throw rope or buoyant rescue aid
Assess risk and enter with flotation device
If submersion for <10 mins - likely good outcome. If >25 mins - likely poor outcome
Remove from water horizontally - spinal precautions rarely necessary
Why remove patients horizontally from the water?
Hypovolaemia after prolonged immersion can cause cardiovascular collapse and arrest
What initial rescue should you do for patients once retrieved from the water?
Check for response
Give 5 rescue breaths with supplemented oxygen
Start CPR as normal
If lots of foam - continue CPR until intubation
Turn victim to side and remove regurgitation material
What is important about post resus care after drowning?
Risk of developing ARDS - use standard protective ventilation stratefies
Consider ECMO for refractory cardiac arrest, hypoxaemia and submersion in ice cold water
Pneumonia common however prophylactic Abx only if sewage/grossly contaminated
Neurological outcome determined by hypoxia
Define hypothermia
<35 degrees
What may increase risk of hypothermia?
Things that decrease conscious level - drugs, alcohol, illness, exhaustion, neglect
Factors that impair thermoregulation - elderly and very young
Why must you be careful diagnosing death in hypothermic?
Patients can have slow small volume irregular pulses and low BP but they may return once warm
Not dead until warm and dead
At 18 degrees, brain survive 10 times as long from circulatory arrest than at 37
Good survival has been reported in arrest and core temp of 13.7 degrees after immersion for 6.5 hours with CPR in adults
How should CPR be modified in hypothermic patients?
<28 degrees 5 min CPR, 5 min break
<20 5 min CPR, 10 min break
Check for pulse for 1 minute - central artery and ECG
Consider using mechanical chest compression
Dont delay intubation
Hold adrenaline and amiodarone until >30 degrees. Then double dose interval (6-10 mins) until 35 degrees
How are arrhythmia’s treated in hypothermia?
Sinus Brady –> AF –> VF –> asystole
Apart from VF, others revert spontaneously as temp increase. Cardiac pacing not indicated unless haemodynamic compromise persist after rewarming
Stop shocks after 3 until temp >28-30
When are avalanche victims not likely to survive?
Buried for >60 mins and in cardiac arrest with obstructed airway on extraction
Buried and in cardiac arrest with K+ >8mmol/L
What other active rewarming techniques can be used?
Forced warm air
Warm infusions
Forced peritoneal lavage
What are the stages of hyperthermia?
Heat stress
Heat exhaustion
Heat stroke –> multi-organ dysfunction and cardiac arrest
What is heat stroke?
Core temp >40.6
Change in mental state
Varying levels of organ dysfunction
2 types:
- exertional
- non exertional - elderly in heat waves
What can predispose someone to heat stroke?
Elderly:
- underlying illness
- medication use
- declining thermoregulatory mechanisms
- limited social support
Lack of acclimitisation Dehydration Alcohol Obesity CVS conditions Skin disease Hyperthyroidism Phaeochromocytoma
What drugs can predispose to hyperthermia?
Anticholinergics Diamorphine Cocaine Methamphetamine Phenothiazines Sympathomimetics Ca2+ blockers Beta blockers
What are the features of heat stroke?
Core Temp >40 Hot dry skin Fatigue, headache, fainting, facial flush, D&V CVS dysfunction - arrhythmia and hypotension Resp dysfunction - ARDS CNS dysfunction - seizures and coma Liver and renal failure Coagulopathy Rhabdomyolysis
What differentials do you have to consider for raised core temperature?
Drug withdrawal syndromes Neuroleptic malignant syndrome Sepsis CNS infection Endocrine disorder - thyroid and phaeochromocytoma
How is heat stroke treated?
Rapid cooling
Haemodynamic monitoring - fluid and electrolytes
Defibrillation as normal
Post resus care as normal
What is used in treatment of malignant hyperthermia?
Dantrolene
What reduces skin resistance to electrocution?
Moisture
What can cause myocardial or respiratory failure in electrocution?
Resp arrest due to paralysis of respiratory muscles or resp depression
Current can precipitate VF if it crosses myocardium during vulnerable period.
Current can cause coronary artery spasm
Asystole ma be primary or secondary to asphyxia following resp arrest
In patients who survive an initial electric shock, what may happen?
Catecholamine release or autonomic stimulation:
- tachycardia
- hypertension
- prolonged QT and transient t wave inversion
- myocardial necrosis
- CK release
What determines long term prognosis for electrical injury?
Severe burns
Myocardial necrosis
Extent of CNS injury
Multiple system organ failure
What level of potassium definetely causes ECG changes
6.7mmol l
What other electrolyte to check with hypokalaemia
Mg
What is refractory anaemia
No improvement of cardiovascular or respiratory symptoms despite 2 doses of adrenaline
Give - IV 500ml bolus and adreanlaine infusion
