Red Book - Cardiogenic Shock

Question 1

Define

Answer 1

Evidence of tissue hypoperfusion

Secondary to…

Primary Cardiac Failure….

After correction of preload

(Extreme end of decompensated failure)

Question 2

Characteristics of cardiogeneic shock

Answer 2

SBP <90mmHg or a deacreas in MAP by >30mmHg

HR > 60

Oliguria

With/without evidence of congestion

Question 3

Pathophysiology

Answer 3

Can by DIASTOLIC or SYSTOLIC

Diastolic —> impaired function —> Rising LVEDP —> pulmonary congestion —> Hypoxia —> ishaemia

Systolic —> Low CO and SV —>. Hypotension —> low coronary perfusion —> Ischaemia

						—> low systemic perfusion —> Compensatory vasoconstrict + fluid retention

COMMON FINAL PATH IS ISCHAEMIA AND VASOCONSTRICTION —> Progessive myocardial DYSFUNCTION

Question 4

Causes:

Answer 4

ACS
Arrythmias
Valves: regurg (chordae rupture, endocarditis)
Decompensated aoritc stenosis

Tampanade - Trauma, surgery, aortic dissection, effusion/pericarditis

High output failure —> anaemia, thyroid storm

Viral - Coxsackie/Adenovirus. —> MYOCARDITIS

Decompensated causes —> Hypertensive disease —> disastolic heart failure
Dilated cardiomyopathy —> Alcohol, Drugs (coke), Peripartum
Restrictive —> infiltartion, sarcoid, amyloid etc
Congenital HOCM

Question 5

Presentation

Answer 5

CVS 
	Cool peripheries
	Prolonged CRT
	Tachy or brady
	Arrythmias
	High if SVR raised, Low if decompensated
	Myocardial ischaemia
	RVF - oedema, raised JVP, RUQ pain

Resp - tachypnoea, hypoxaemia, pulmonary oedema

Neuro - low GCS/mental state

Renal - oliguria

Question 6

Approach to treating cardiogenic shock

Answer 6

Reduce myocardial demand AND improve myocardial oxygen delivery

DEMAND: — reduce HR or reduce after load (vasodilators/diueretics, sedation, beta blockers??)

DELIVERY: — Improve myocardial perfusion (Vasodilators, Inotropes (may increased consumption)
Increase O2 carriage —> FiO2, blood transfusion

Question 7

Management

Answer 7

ABCDE

A / B - 100% intuabate, NIV if needed
C - iv access and bloods
250mls fluid bolus, warm, cautious
Echo/CVP

Intoropic options

Question 8

What investigations

Answer 8

Bloods: FBC, U&E, LFT, TFT, Troponins, BNP, clotting

Micro: viral serology, cultures

Cardiac - Echo, 12 lead ECG

Radiology - CXR

Question 9

Inotropic Options

Vasodilator options

Answer 9

Goals is to reduce demand (afterload) and improve delivery

Use of INOTROPES, VASODILATORS, VASOPRESSORS AND MECHANICAL

Adrenaline —> low dose —> b1/2 - tachy, inotropic, dilation
High dose —> a1, constriction

Dobutamine —> B1, tachy with inotropy, and dilation (consider norad to offset)
B2 (some, dlation)

VASODILATORS

PDE3 inhib - Milrinone/enoximone —> increased cAMP, lower PVR/SVR, inotrope and lusitrope)
good in diastolic failure

GTN - NO donor - VENOdilation

VASOPRESSORS
Vasopressin V1 - vasoconstriction V2, water retention
Norad a1

Levosimendin

IABP/VAD

Question 10

How does levosimendin work

Answer 10

Sensitises troponin C to calcium —> inotropy

Opens K(atp) channels, increases perfusion, reduce preload and afterload

INCREASES CONTRACTILITY WITHOUT INCREASING DEMAND

Question 11

How does the IABP work

Answer 11

Works on a principle of Countercurrent pulsation

Goal is to improve oxygen delivery whilst reducing oxygen demand

Inserted into femoral artery

Balloon is distal to the left subclavian artery

Helium pushed into balloon in diastole —> augments diastolic BP —> improves perfusion to coronary

Deflates in systole —> reduces afterload.

Question 12

Describe how the pump inflates and deflates in terms of timing

Answer 12

Either ECG, or via the invasive BP trace.

ECG: BP
Inflation - middle T wave dicrotic notch
Deflation - peak of R wave just before systolic upstroke

Question 13

Contra-indications to IABP

Answer 13

1) aoritic regurg
2) aortic dissection
3) severe PVD

Relative
	Arterial tortuousity
	LV outflow obstruction
	Sepsis
	Can’t be anticoagulated - coagupathic or HIT

Question 14

Complications of an IABP

Answer 14

Vascular:
	Failure
	Bleeding
	Pseudoaneurysm
	Perforation

Balloon:
Mesenteric/renal ischaemia (balloon position)
Left upper limb and cerebral iscahemia (position too high)
Helium embolus
Haemolysis
Thrombocytopenia

Question 15

What is a VAD

Answer 15

Surgical placed
Mechanical device

Supports Left (LVAD), Right (RVAD) or both (BiVAD) ventricles

BiVAD is uncommon as RHF usually due to LV failure and will therefore improve

Reduce myocaridal work —> ventricles rest rest there is forward flow and perfusion

Impella - Centrifugal flow

Used as a bridge gto recovery instead of VA ecmo in heart failure
bridge to transplant
long term heart failure

Question 16

Complications of a VAD

Answer 16

Bleeding post insertion
Product transusions
Re-exploration

Cardiac tampanade
Decreased VAD flow, increased CVP, reduced MAP, rising inotropes
Immediate decompression

Haemodynamic disturbance, specially if hypovolaemic

RV failure
RV dilates, high atrial pressures (20mmHg), reduced contractiliy
Tricuspid regurg

Fluid overload

Infection

Intra-cardiac thrombosis due to decreased VAD flows