Editing Circulation

== Primary causes of dysfunction ==

# Hypovolaemia (haemorrhage/dehydration)
# Sepsis
# Cardiac
# PE

== Assessment (see 'assessment' tab) ==

* Chart review
* RR
* HR
* BP
* JVP
**
* Temp
* UO
* IV lines
* Tubes and drains
* Drug chart
* Fluid balance
* History
* Case notes
* Examination
**

*

* Tests
** Bloods
** CXR
** ECG
***

*
*

== Specific problems ==

* '''Tachycardia'''
**
* '''Tachyarrhythmia'''
**

*
* '''Supraventricular tachycardia''' (a/w increased risk of cardiac event)
** Sinus
*** Caused by pain/anxiety, fever, hypovolaemia, hypovolaemia/anaemia, PE; less commonly heart failure, MI, thyrotoxicosis, phaeochromocytoma
** Atrial
*** AF
**** See separate topic under 'Cardiology'
*** Atrial flutter
**** Regular flutter P waves at 300/min. QRS is normal with variable AV block. There is usually underlying cardiac disease.
**** AF and flutter may be present in the same patient.
**** May respond to adenosine
**** Treatment is cardioversion, digoxin or verapamil.
****
** Paroxysmal SVT
*** Any tachycardia originating in AV node, atria or sinoatrial node
*** Changes to P waves or missing P waves
* '''Ventricular'''
** PVC
*** Consider hypoxia, hypokalaemia, hypocapnia
** Ventricular tachycardia
** VF

* '''Bradyarrhythmia'''
** Problematic if associated with hypoperfusion or hypotension
** Causes:
*** Autonomic
**** Pain, especially visceral
**** Raised ICP
**** Beta-blockers
**** Epidural
*** Non-autonomic
**** MI, especially inferior MI
**** Sepsis
**** Hypoxia
**** Digitalis toxicity
**** Hypothyroidism
**** Hypothermia
** Management:
*** Atropine 0.6-1.2mg may help
*** Pacing may be needed
*** Isoprenaline infusions can be used in ICU
* '''Heart block'''
** RBBB
*** Right ventricular depolarisation occurs via the left ventricle
*** M-shaped QRS in V1, V2 and V3
*** RBBB with left axis deviation suggests bifascicular block - discuss with cardiology
** Left ventricle depolarises via right ventricle
** M-shaped QRS in V5, V6, I and aVL. W-shaped QRS in reciprocal leads, III and aVF

== '''Management of arrhythmias:''' ==

* Most important thing is haemodynamics initially.
** Assess:
*** Vitals
*** Peripheral perfusion
*** Cardiac ischaemia/CHF
*** Level of consciousness
*** Management:
*** For all arrhythmias:
**** '''Check and correct electrolytes'''
**** '''Oxygen if needed'''
**** '''Optimise fluid'''
* ECG
* ?telemetry
* Tachyarrhythmia:
** Unstable - cardioversion
** Stable:
*** Supraventricular - may respond transiently to valsalva. beta blockers/digoxin/amiodarone. Adenosine 6mg or 12mg can be given to block the AV node (avoid in asthmatics and the presence of dipyridamole, but otherwise relatively safe in inexperienced hands).
*** Paroxysmal SVT: vagal stimulation or adenosine
*** VT: lidocaine/procainamide/amiodarone can be given. Cardioversion generally required. Especially urgently if there is compromised cardiac output.
* Bradyarrhythmia:
** Sustained - atropine or beta adrenergic agonist
** Transient - nothing
* Heart block: 
** Persistent high-grade second degree or third degree: insertion of PPM

== '''Acute coronary syndromes''' ==

* Acute myocardial infarction
** Transmural myocardial infarction
** Q-wave myocardial infarction
** STEMI
*** Presentation:
**** Dyspnoea
**** Hypotension
**** Decreased organ perfusion
**** Acute dysrhythmias
**** Sudden pulmonary oedema
**** Cardiac arrest
**** Acute upper abdominal pain
*** Diagnosis
**** ST-segment elevation of >1mm in the leads overlying the infarct and inversion in the leads opposite to it
***** Anterior - primarily V1-V4
***** Inferior - primarily II, III, aVF
***** Posterior - isolated ST depression V1 and V2
**** T-waves flatten and invert within hours to days of MI
**** Q waves develop over 1-2 days
**** Changes may be masked by a pre-existing LBBB
*** Treatment:
**** Oxygen
**** Analgaesia
**** Periop/ICU
**** Cardiology for consideration of primary PCI
**** Aspirin 300mg
**** GTN can help with pain if no contraindication
**** Treat anything that might exacerbate it: anaemia, fluid status, hypertension
**** Serial ECGs and troponins
* Non-Q-wave myocardial infarction
** Sub-endocardial infarction
** Non-STEMI
* Unstable angina

== '''Cardiac failure''' ==

* Aetiology
** Conditions affecting preload
*** Hypovolaemia
*** Fluid overload (most common perioperatively)
*** Pneumothorax/cardiac tamponade
** Conditions affecting intrinsic myocardial function
*** Ischaemia
*** Infarction
*** Dysrhythmias
*** Chronic heart failure
*** Hypocalcaemia (and other electrolytes)
*** Myocardial depressant factors (e.g. sepsis)
*** Pneumothorax/cardiac tamponade
** Conditions affecting afterload
*** Aortic/pulmonary valvular stenosis
*** PE
*** Pneumothorax/cardiac tamponade
*** Aortic dissection
* Diagnosis
** Acute dyspnoea, orthopnoea and tachypnoea
** Tachycardia, diaphoresis, hypertensive
** Gallop rhythm
** Bibasal crepitations, wheeze (cardiac asthma), pink frothy sputum
** CXR - fluid in the horizontal fissure, peribronchial cuffing, upper lobe diversion, perihilar bat's wing appearance, Kerley B lines (rare)
* Treatment:
** Administer oxygen
** ECG
** Treat any underlying cause
** Sit patient up
** Consider CPAP
** Diuretics
** IV opioids can help
** Reduce afterload if possible (nitrates)
** Consider ICU
* '''Cardiogenic shock'''
** Severe impairment of cardiac function with BP <90mmHg (or 30mmHg less than 'normal')
** Most common causes are severe myocardial ischaemia or infarction

== '''Hypertension''' ==

* Refer to cardiology if BP persistently >220/120mmHg with signs of organ dysfunction

== Cardiac monitoring ==

* BP
** Non-invasive
** Invasive
*** Easiest is probably arterial at radial artery
*** Central venous pressure
**** Indicates preload of pulmonary circulation and a rough guide to systemic preload
**** Best route in elective setting is internal jugular vein with USS
**** Does NOT equal intravascular volume
**** Subject to a lot of variables
**** Indications:
***** Fluid replacement for hypovolaemia when conventional access is impossible or going to be difficult to manage
***** Measure effect of vasoactive drugs on venous capacitance
***** Aid diagnosis of RHF
****
* Trans-oesophageal Doppler
** Measures blood velocity in the descending aorta
* TTE/TOE
** Assessment of preload and cardiac contractility before and after an intervention
** Diagnosis of major cardiac structural abnormalities


For haemodynamic drugs, see separate topic under 'Pharmacology'
[[Category:Critical care]]