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Perioperative optimization of the circulatory function (assessment (Swan…
Perioperative optimization of the circulatory function
Perioperative cardiovascular complications
Myocardial ischemia / necrosis
Acute heart failure
Complications resulting from organ hypoperfusion: acute renal failure, gut ischemia, MODS
Cerebral ischemic stroke
Factors contributing to intraoperative hypovolaemia
VASODILATATION
BLOOD VOLUME loss
Central venous pressure: 2-10 mmHg
Pulmonary artery pressure: 6-15 mmHg
Too low end-diastolic volume → ↓ stroke volume (→ ↓ cardiac output)
Too high end-diastolic volume → ↑ myocardial oxygen consumption, risk for subendocardial ischemia
Optimal central venous pressure
Leg elevation or Trendelenburg position
Rapid volume load 200-300 mL infusion
↑ arterial blood pressure indicates for fluid responsiveness
The most sensitive leads combinantions
Two leads: V4 and V5 (90%) II and V4 (82%) II and V5 (80%)
Three leads: II, V4 and V5 (96%) V3, V4, and V5 (94%)
As a routine practice - the best combination: II, III, and V4 (alternatively: V3 or V5)
assessment
Swan-Ganz catheter
Pulmonary artery pressure monitoring
Cardiac outputrs
Pulmonary artery hemoglobin saturation with oxygen
Continuous Cardiac Output measurement
Advantages:
High accuracy
High number of vital parameters (Cardiac Output and its derivatives , SVO2)
RV preload calculatio
Disadvantages:
Invasiveness risk of complications,
Short time of safe use (3 days)
Trans-pulmonary thermodilution (PICCO)
Benefits:
Stroke volume variation and pulse pressure
Decreased invasiveness
Disadvantages:
Need for calibration
Catheter in SVC and femoral artery
Pulse contour analysis (e.g. Flo-track)
Benefits:
No need for calibration
High corelation with thermodilution method
Stroke volume variation analysis
Disadvantages:
Reduced corelation with thermodilution method in hyperdynamic circulation
Trans-esophageal Doppler
Benefits:
Low invasiveness
Assessment of flow changes in descending aorta
Disadvantages:
Need for probe repositioning
Need for measurement of descending aorta diameter
Inaccurate cardiac output measurement due to place of flow assessment
Not tolerated after extubation
Thoracic electrical bioimpedance
Benefit:
The least invasive method of cardiac output assessment
Disadvantages:
Limited corelation with reference methods
Vasodilators, hypertension, anemia, hyperdynamic circulation reduce measurement accuracy
NICO – Non-invasive cardiac output
Benefits:
Pediatric application
Disadvantages:
Applicable to mechanically ventilated patients only
SCVO2
Continuous measurement of superior vena cava hemoglobin saturation with oxygen
Benefits:
Reduced invasiveness
Well tolerated after extubation
well correlated with SVO2
Dynamic parameters of volume-responsiveness
Pulse pressure variation (PPV)
Stroke volume variation (SVV)
Systolic pressure variation (SSV)
influence of anesthetics on the cardiovascular function
influence of inflammatory response to surgical trauma on the cardiovascular function
Increased venous capacity (→ hypovolemia)
Decreased systemic vascular resistance (→ hypotension)
Decreased myocardial contractility (→ hypotension, low cardiac output)
Increased endothelial permeability (→ hypovolemia, edema)
Pharmacological treatment of acute heart failure
Drugs decreasing pulmonary vascular resistance:
NO, iloprost, PDE3-inhibitors, levosimendan, sildenafil
Nitroglycerin
↓ systemic vascular resistance – ↑ stroke volume
↓ wall tension → ↓ myocardial oxygen demand
Maintaining coronary perfusion pressure
effective treatment of pulmonary hypertension and right ventricular failure
Does not result in systemic vasodilatation
Inotropes
Catecholamines
Phosphodiesterase III inhibitors (PDE3)
Calcium sensitizer: levosimendan (Simdax)
Catecholamines
Require deep vein cannulation
Administered as continuous infusion
Act by increase of intracellular cAMP concentration
Restoring of the receptor sensitivity by:
The improvement of acid-base balance
Ca++ & Mg++ balance
Normothermia
Steroids
Phosphodiesterase III inhibitors
Bipiridine derivatives: amrinone and milrinone; Midazole derivative: enoximone
increase of intracellular cAMP
Dilate systemic and pulmonary vessels
No chronotropic effect
Lusitropic effect
Synergistic effect with catecholamines Inotropic effect limited to 48 hour
Levosimendan
Calcium sensitizer
Inotropic effect without increase in myocardial oxygen consumption
Vasodilating effect
Lusitropic effect
High costs
treatment of decompensated chronic heart failure
„Pharmacological bridge” to mechanical circulatory support
Drugs affecting systemic vascular resistance:
Increase: catecholamines, vasopressin
Decrease: nitroglycerine, ACE-inhibitors, PDE3-inhibitors
Vasopressin
Side effects: visceral and skin vessels vasoconstriction
drugs for hypotension treatment after anesthesia induction
Ephedrine
• a1, b1 and b2 adrenergic receptor agonist
• Positive inotropic and chronotropic effects
• Vasoconstrictor
• intravenously in doses of 2,5-5mg
Fenylephrine
• a1-receptor agonist
• Administered not as continuous infusion
most commonly during cardiopulmonary bypass
