Getinge PICCO Pro AQT

CPB weaning

 CROSS CLAMP- good visualisation of surgical fields but may result in myocardial ischaemia without adequate protection


 MYOCARDIAL PRESERVATION
crystalloid cardioplegia
Na 147 K 20 Mg 16 Ca 2 Cl 204 procaine 1 mmol/L
cold

does not prevent ion fluxes and continued influx of Ca, Cl , contributing to depletion of ATP and intracellular calcium overload, thought to be critical in development of myocardial stunning

blood cardioplegia
- most common protective strategy
-however- cold blood cardioplegia- increased viscosity- limits myocardial perfusion
-if warm- may reduce reperfusion injury
-improves o2 carriage (compared to crystalloids)
-improves buffering capacity
-multiple doses may be used
-provides antioxidants

for anterograde (via ascending aorta or aortic sinus, with competent AV, Aortic root pressure of at least 60mmHg for coronary perfusion)

alternative cardioplegia methods (without protection)
- intermittent aortic cross clamp/ induced VF

weaning from CPB
- rewarmed to naso/oeso temp 35-36
-core-periph difference <6 degrees)
-shivering-BAD
-overheting-BAD (>36)

intracardiac procedure- de-airing
epicardial pacing wires to protect against arrhythmias
acid base imbalances, electrolytes
ventilation recommenced
anaesthesia/analgesia/nmba suppplemented
monitors
myocardial support instituted

separation
-stable heart rhythm, warm, all above factors addressed
-venous line partially clamped-heart fills
-pump speed reduced-if BP maintains-->
-venous line fully clamped
-pump stopped when heart is appropriately filled and functioning well. (may need tropes, optimal hr)
-can continue to fill with arterial line  


 causes of failure to wean
poor preop ventricular function
inadequate myocardial protection
prolonged cross clamp time
imperfect surgical repair
electrolyte imbalance
acidosis
arrhythmias

TEE

Absolute contraindications:
Esophageal spasm.
Esophageal stricture.
Esophageal laceration.
Esophageal perforation.
Esophageal diverticula (e.g. Zenker's diverticulum).

Relative contraindications:
Large diaphragmatic hernia may significantly hinder TEE imaging because of lack of transducer mucosal approximation.
Atlantoaxial disease and severe generalized cervical arthritis: TEE should never be performed if there is any question about stability of cervical spine.
Patients who received extensive radiation to the mediastinum: this can cause significant difficulty in probe manipulation within the esophagus and is a relative contraindication if the anatomy of the esophagus is not known.
Upper gastrointestinal bleeding, significant dysphagia and odynophagia are also relative contraindications

Indication:
cardiac output
valve
congenital heart disease
evaluation of LA and LA appendage before cardioversion

highest risk of adverse outcome from IE

highest risk of IE:
prosthetic valve or material
previous IE
congenital HD-

• unrepaired cyanotic CHD,


• completely repaired CHD within 6 mths of procedure,


• repaired CHD with residual defects at site or adjacent to it (which prevents endothelisation), cardiac transplant recipients who develop cardiac valvulopathy

Valvular lesions- MR

MR causes

leaflet( MVP/ endocarditis/ rheumatic fever), MI

clinical examination

- displaced forceful apex beat

-AF

-soft S1, PSM radiating to axilla , loud S3

TEE good coz MV closest to esophagus

CXR: dilated LA , +/-

ECG:AF, LA dilatation

SV usually preserved until late

surgery if functional status <4 METS

if mixed lesion- deal with dominant lesion first.

Goals: high normal HR (slower--> more time for diastolic filling and larger volume regurg), adequate preload, low afterload, low PVR

revised cardiac risk index