General Flashcards
In the absence of adverse features, regular narrow-complex tachyarrhythmia can be treated with:
vagal manouevres or adenosine In the absence of adverse features you should start with vagal manoeuvres: Carotid sinus massage or the Valsalva manoeuvre will terminate up to a quarter of episodes of paroxysmal SVT. An ECG (preferably multi-lead) should be recorded during each manoeuvre. If the rhythm is atrial flutter with 2:1 conduction, slowing of the ventricular response will often occur and reveal flutter waves, if this is the case seek expert help. If vagal manoeuvres do not terminate the arrhythmia or demonstrate underlying atrial flutter consider using adenosine. If vagal manoeuvres have been attempted and the arrhythmia persists (and it is not atrial flutter) give adenosine 6 mg IV as a very rapid bolus. Use a large cannula and a large (e.g. antecubital) vein. Remember to: check for contraindications such as asthma warn the patient that they will feel unwell and experience chest discomfort for a few seconds after the injection record the ECG continuously (preferably multi-lead) during the injection. If the ventricular rate slows transiently, but then speeds up again, look for atrial activity such as atrial flutter (or other atrial tachycardia) and treat accordingly. If there is no response to adenosine 6 mg, give a 12 mg bolus. If there is again no response give one further 12 mg bolus. Lack of response to adenosine will occur if the bolus is given too slowly or into a small peripheral vein.
Hyperkalaemia in cardiac arrest treatement
- give 10 ml 10% calcium chloride IV by rapid bolus injection to antagonise the toxic effects of hyperkalaemia at the myocardial cell membrane
- sodium bicarbonate: 50 mmol IV by rapid injection (if severe acidosis or renal failure)
- glucose/insulin: 10 units short-acting insulin and 25 g glucose IV by rapid injection
- consider haemodialysis: this may be an option for cardiac arrest induced by hyperkalaemia which is resistant to medical treatment. Several dialysis modes have been used safely and effectively in cardiac arrest, but this may only be available in specialist centres that offer acute renal replacement therapy in critically ill patients.
What is this?
Mobitz Type II AV block
There is a constant PR interval in the conducted beats but some of the P waves are not conducted (i.e. followed by QRS complexes), in this case producing 2:1 AV block. This may occur randomly, without any consistent pattern. People with Mobitz II AV block have an increased risk of progression to complete AV block and asystole.
2:1 AV block describes the situation in which only alternate P waves are followed by a QRS complex. 2:1 AV block may be due to Mobitz I or Mobitz II AV block and it may be difficult to distinguish which it is from the ECG appearance. If bundle branch block is present (broad QRS complexes) as well as 2:1 block, this is likely to be Mobitz II block.
If tachyarrythmia shows adverse features….
Synchronised DC shock (up to 3 attempts) If this does not work give… Amioderone 300mg IV (10-20 mins) Repeat shock Then give amioderone 900mg over 24 hours
Treatment of acute astma
- Oxygen to maintain SpO2 94–98%. (CO2 retention is not usually aggravated by oxygen therapy in asthma).
- Salbutamol 5mg or terbutaline 10mg via an oxygen-driven nebuliser.
- Ipratropium bromide 0.5mg via an oxygen-driven nebuliser.
- Prednisolone oral 40–50mg or hydrocortisone IV 100mg if unable to take oral.
- No sedatives of any kind.
- Repeat chest radiograph only if pneumothorax or consolidation are suspected or patient requires mechanical ventilation.
IF LIFE-THREATENING FEATURES ARE PRESENT:
- Discuss with senior clinician and ICU team.
- Consider IV magnesium sulphate 1.2–2g infusion over 20 minutes (unless already given).
- Give nebulised beta2 agonist more frequently e.g. salbutamol 5mg up to every 15–30 minutes or (if special nebuliser available for continuous nebulisation) 10mg/hour.
Acute severe asthma
Features of acute severe asthma:
Peak expiratory flow (PEF) 33–50% of best (use % predicted if recent best unknown).
Can’t complete sentences in one breath.
Respiration >25breaths/minute.
Pulse >110beats/minute.
normocarbia
(PaCO2 4.7-6.0 kPa)
Life threating asthma
Any one of the following, in a patient with severe asthma:
- Peak flow < 33% best or predicted;
- Arterial oxygen saturation (SpO2) < 92%;
- Partial arterial pressure of oxygen (PaO2) < 8 kPa;
- Normal partial arterial pressure of carbon dioxide (PaCO2) (4.6–6.0 kPa);
- Silent chest;
- Cyanosis;
- Poor respiratory effort;
- Arrhythmia;
- Exhaustion;
- Altered conscious level;
- Hypotension.
In these patients following senior advise would give amiopylinne. Loading dose is 5mg Kg IV over 20 mins unless already on on maintanace)
Unstable angina and NSTEMI treatment
- Anti-thrombotic Aspirin
- LMW heparin or fondaparinux
- platelet inhibitor such as clopidogrel, prasugrel or ticagrelor
- if very high risk: glycoprotein IIb/IIIa inhibitor
- Pain relief
- Nitrate
- Morphine
- Oxygen if patient is hypoxic
- Myocardial protection Beta blocker
- Coronary angiography/PCI in most patients
Adverse features
The following adverse features indicate that a patient is at risk of deterioration either wholly or partly because of their arrhythmia: Shock - features include: hypotension (systolic blood pressure <90 mmHg), pallor, sweating, cold extremities, confusion and impaired consciousness Syncope - transient loss of consciousness because of global reduction in blood flow to the brain Heart failure - features include: pulmonary oedema and/or raised jugular venous pressure (with or without peripheral oedema and liver enlargement) Myocardial ischaemia -features include: typical ischaemic chest pain and/or evidence of myocardial ischaemia on a 12-lead ECG
In patients with adverse features of a bradycardia?
Give Atropine 500 mcg IV.
If there is not a satisfactory response, this dose of atropine may be repeated (every 3-5 mins) up to a maximum total doses of 3 mg.
If atropine fails to provide a satisfactory response you should consider transcutaneous pacing. If this is not available immediately options for treatment using other drugs are listed in the algorithm.
Absolute contraindications to fibrinolytic therapy
- Previous haemorrhagic stroke
- Other stroke or CVA within six months
- CNS damage or neoplasm
- Active internal bleeding
- Aortic dissection
- Recent major surgery or trauma
- Known bleeding disorder
What is this?
Agonal rhythm occurs in dying patients.
It is characterised by the presence of slow, irregular, wide ventricular complexes, often of varying morphology. These are unlikely to produce a pulse.
Which of the following drugs may be used for the treatment of sinus tachycardia?
Sinus tachycardia is not an arrhythmia. It is a common physiological response to stimuli such as exercise or anxiety. Do not attempt to treat sinus tachycardia with cardioversion or anti-arrhythmic drugs as treatment is directed at the underlying cause.
What is this?
Mobitz Type I AV block (also called Wenckebach AV block)
The PR interval shows progressive prolongation after each successive P wave until a P wave occurs without a resulting QRS complex. Often the cycle is then repeated.
The need for treatment is dictated by the effect of the arrhythmia on the patient and the risk of developing more severe AV block or asystole.
What is this?
First-degree atrioventricular (AV) block is present when the PR interval is > 0.20 s and is a common finding. It represents a delay in conduction through the AV junction (the AV node and immediately adjacent myocardium).
First-degree AV block rarely causes any symptoms and as an isolated finding rarely requires treatment.
The normal PR interval is 0.12-0.20 s (or 3-5 small squares).
What is this?
Third-degree atrioventricular block
Extreme bradycardia may sometimes precede cardiac arrest and this may be prevented by prompt and appropriate treatment.
In third-degree (complete) AV block, there is no relationship between P waves and QRS complexes; atrial and ventricular depolarisation arises independently from separate ‘pacemakers’. The site of the ‘pacemaker’ stimulating the ventricles will determine the ventricular rate and QRS width.
A pacemaker site in the AV node or proximal bundle of His may have an intrinsic rate of 40-50 min-1 or sometimes higher and will have a narrow QRS complex unless additional bundle branch block is present.
A pacemaker site in the distal His-Purkinje fibres or ventricular myocardium will produce broad QRS complexes, often have a rate of 30-40 min-1 or less, and is more likely to stop abruptly, resulting in asystole.
What is this?
This shows a 3:1 AV block, which is less common and is usually a form of Mobitz II AV block.
Immediate decisions about treatment of these rhythms will be determined by the effect of the resulting bradycardia on the patient. After identifying and providing any necessary immediate treatment, continue cardiac monitoring and arrange expert cardiological assessment.
