What is the pericardium
The pericardium is a sac surrounding the heart.
-
Two tissue layers:
- Visceral, a thin tissue-like layer
- Parietal, a more fibrous, rigid layer
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Pericardial cavity
- holds 20 – 50 ml of pericardial fluid.
Pericardial pressure is similar to pleural pressure varying with respiration between –4 to +4 mm Hg.
Pericardium function
- Prevents infection
- Lubricates the heart
- Facilitates motion within the sac
-
Protects the heart from excessive displacement
- maintains optimum shape of the heart
-
Applies a compensatory hydrostatic pressure to the heart
- to compensate for alterations in gravitational force
- maintains optimum shape of the heart
- to compensate for alterations in gravitational force
Acute pericarditis
what is it
what are the causes
Inflammation of the pericardium
Causes:
-
infection
- viral
- bacterial
- fungal
- tuberculous
- myocardial infarction
- trauma/cardiotomy
- metastatic disease
- drugs
- mediastinal radiation
-
systemic diseases:
- Rheumatoid Artheritis
- Lupus
- Scleroderma
Acute Pericarditis - diagnosis
1.Sudden onset of severe chest pain exaggerated by inspiration
2.Diffuse ST segment elevation, PR segment depression, T wave inversion
3. Pericardial friction rub
Acute Pericarditis - treatment
Treatment:
1. Salicylates or NSAIDS
2. Analgesics (Indomethacin)
3. Corticosteroids
Acute pericarditis in the absence of effusion does not alter cardiac function.
Pericardial Effusion
what is it
causes
diagnosis
Accumulation of pericardial fluid in the pericardial cavity
-
Causes:
- Idiopathic-unknown cause
- Neoplastic
-
Diagnosis
- ECHO - the most useful method for clinical detection of effusion – it is very accurate on estimating effusion size
-
Signs and symptoms depend on the rate of fluid accumulation
-
Acute: with an rapid effusion, the pericardium does not have time to accommodate, so intrapericardial pressures increase significantly and cardiac tamponade results - Even small volumes of fluid (100 – 200 ml) that accumulate rapidly will cause cardiac tamponade
-
Gradual: if the effusion develops gradually, the pericardium stretches to accommodate fluid - A large volume of fluid (up to 1000 ml) can accumulate without a significant increase in pressure
-
Cardiac Tamponade
What is it
- Cardiac tamponade exists when an increase in pericardial pressure impairs diastolic filling of the heart.
- Cardiac filling is related to the diastolic transmural (distending) pressure across each chamber
- Transmural pressure = Pressure within the chamber - extracavity pericardial pressure
- Any increase in pericardial pressure relative to the pressure within the chamber reduces filling
- Medical Emergency
- Transmural pressure = Pressure within the chamber - extracavity pericardial pressure
- Any increase in pericardial pressure relative to the pressure within the chamber reduces filling
Cardiac Tamponade
Signs and Symptoms
- Increased central venous pressure
- JVD
- Equalization of cardiac filling pressures
- Decreased CO, SV
- Hypotension
- Activation of the SNS
- Tachypnea
- Muffled heart sounds
- Decreased voltage on ECG
- Pulsus paradoxus
Cardiac Tamponade
Treatment
removal of fluid
- Pericardiocentesis
- Subxiphod pericardiostomy
- Thoracic pericardiostomy (open or thoroscopic)
Cardiac Tamponade
Anesthetic Management
- Expand intravascular volume
- Increase myocardial contractility
- Isoproterenol
- Correct metabolic acidosis
- Can do under local, or with Ketamine
- Isoproterenol
Constrictive Pericarditis
What is it
Causes
Fibrous scarring and adhesions of the pericardial cavity that creating a rigid, stiff shell around heart that limits filling of the heart
Causes
- Idiopathic
- Previous cardiac surgery
- Exposure to radiotherapy
- TB
Constrictive Pericarditis sxs
- CVP, RAP, PCWP elevated
- CO decreased
- Fatigue
- Atrial dysrhythmias
- Edema
- Ascites
- Hepatomegaly
- Pulsus paradoxus
- JVD
Constrictive Pericarditis - treatment
Surgical stripping and removal of adherent constricting pericardium (pericardiectomy)
Constrictive Pericarditis - anesthetic management
-
Minimize changes to HR, SVR, preload, and contractility
- use: ketamine, etomidate, pancuronium
- AVOID bradycardia
-
Maintain intravascular volume to AVOID hypotension
- have large bore IV’s, A-line
- Blood transfusions may be necessary to treat blood losses associated with pericardiectomy
- use: ketamine, etomidate, pancuronium
- have large bore IV’s, A-line