Pericardial diseases

Question 1

The pericardial cavity normally holds _______ ml

with a chronic pericardial effusion, the pericarial cavity can have as much as ________ mLs of fluid without sidnificant increases in pressure

however with an acute pericardial effusion __________ will cause ____________

Answer 1

_{The pericardial cavity normally holds _______ ml}

_{with a chronic pericardial effusion, the pericarial cavity can have as much as ________ mLs of fluid without sidnificant increases in pressure}

_{however with an acute pericardial effusion __________will cause____________}

1. 20-50 mL
2. 1000 mL (1L)
3. even small voumes (100-200 mL) that accumualte rapidly
4. an increase in cardiac pressure and cardiac tamponade

Question 2

what 2 features distinguish acute pericarditis from anginal pain?

Answer 2

1. the pain gets worse with INSPIRATION or laying down (recumbancy)
2. EKG shows diffuse ST and T wave changes (In all leads?).

(another diagnostic criteria is the presesnce of a friction rub)

Question 3

What is the typical pericardial pressure

Answer 3

• Similar to pleural pressure it varies with respirations between -4 and +4mmHg

Question 4

Function of the pericardium

Answer 4

1. Lubricates the heart
2. Facilitates motion within the sac
3. Protects the heart from excessive displacement
4. Maintains optimum shape of the heart
5. Applies compensatory hydrostatic pressure to the heart to compensate for alterations in gravitational force

Question 5

Bonus- Whats the IV dosing for midazolam? Oral?

Answer 5

IV premedication: 1-2.5mg (max 5mg)

Inucion agent: 0.1-0.2 mg/kg

Oral premed: 0.5mg/kg (max 20mg)

Question 6

What is the pericardium

Answer 6

• Sac surrounding the heart,
• composed of two layers
  
  • Visceral- thin, tissue like
  • Parietal- more rigid, fibrous layer

Question 7

What are the three most frequent responses to pericardial injury?

Answer 7

1. Acute Pericardidis
2. Pericardial Effusion
3. Constrictive Pericarditis

Question 8

Bonus- What’s the dosing for ketamine?

What is ketamine’s protein binding?

Answer 8

1. Induction: 0.5-2 mg/kg IV
2. sedation: 0.2-0.5 mg/kg IV
3. maintenance: 1-2 mg/kg/hr IV
4. IM/PR: 5-10 mg/kg
5. 12% protein bound, (low compared to the other induction agents)

Question 9

Acute pericarditis →what causes it , what is the treatment?

Answer 9

1. Often caused by: virus, infections, MI, trauma, cancer, drugs ( immunosupressants), systemic diseases RA, SLE,
2. Often labeled acute BENIGN pericarditis→usually unaccompanied by a pericardial effusion or tamponade and RARELY progressive to restrictive pericarditis
3. Treatment:
   
   1. Salicylates/NSAIDS
   2. Analgesics (Indomethicin-blocks prostaglandins)
   3. Corticosteroids

Question 10

T/F Acute pericarditis always alters cardiac function

Answer 10

False

Only in the presence of effusion is cardiac function altered

Question 11

What is pericardial effusion? what are the signs/symptoms?

Answer 11

1. Accumulation of fluid in the pericardial cavity, (idiopathic or neoplastic origin)
2. Rate of fluid accumulation determines symptoms
   
   1. Acute:
      
      • pericardiaum lacks time to adapt
      • intrapericardial pressures increase rapidly
      • 100-200 mL of fluid can cause tamonade
   2. Chronic/gradual:
      
      • pericardiaum can stretch to acomidate fluid
      • up to 1000 mL can accumulate without a change in pressure

​​(ECHO is very accurate on measuring the size of the effusion)

Question 12

Why is there a rapid rise in CVP with cardiac tamponade?

Answer 12

As pericardial pressures increase the right atrial pressure will increase in parallel

so the right atrial pressure is a REFLECTION of the intrapericardial pressure

when CVP starts to change signs and symptoms of cardiac tamonade develop

Question 13

In chronic pericardial effusion how much fluid can accumulate before symptoms are noticed

Answer 13

Up to 1000ml

the slow rate of accumulation allows for the pericardium to stretch without a significant rise in pressure

Question 14

What is the most useful method for detecting and estimating the size of pericardial effusion

Answer 14

ECHO

Question 15

What is impaired in cardiac tamponade

Answer 15

Diastolic filling→ Filling is related to transmural pressure across the chamber, so even a small rise in pressure can impair diastolic filling (low pressure chamber)

Question 16

How can transmural pressure be calculated

Answer 16

Transmural pressure = Chamber pressure - extracavity pericardial pressure

Question 17

Cardiac tamponade s/s

Answer 17

1. Becks triad - 75% oof acute tamponade exibit
   
   1. ​Distant muffled heart sounds
   2. Juggular Venous Distention
   3. Hypotension
2. ​​​Equilization of Cardiac filling pressures
3. Narrow pulse pressures
4. decreased CO and SV will activate the SNS leading to tachycardia
5. Increased cetral venous pressure→reflection of increased transmural pressure and resistance to atrial filling
6. Decreased voltage on EKG → ​Accumulation of fluid
7. Pulsus paradoxus
   
   • >10mmHg drop in SBP during inspiration
   • pulse wave amplitude on A-line will also decrease
8. Tachypnea→ less room for expanionin the thoracic cavity

Question 18

Definitive treatment treatment for cardiac tamponade

Answer 18

1. Pericardiocentesis
2. Subxiphoid pericardiostomy
3. Thoracic pericardiostomy

Question 19

Anesthetic management for cardiac tamponade

Answer 19

Must manage until definitive treatment can be done!!!!

GOAL = maintinence of adequate CO and BP

1. Give fluids to expand volume
2. Increase contractility (Isoproterenol)
3. Correct acidosis (this will increase BP and HR)

Question 20

Bonus- What are the basic pharmacokinetics for propofol

Answer 20

• Onset: 30 sec
• DOA: short- redistributes in 2-8 min for wakeup
• Vd- 3.5-4.5 L/kg
• E1/2- 0.5-1.5 hrs

Question 21

Constrictive pericarditis patho

Answer 21

Scarring/adhesions of the pericardium leads to a rigid, stiff shell around the heart

Impairs diastolic filling (heart cannot relax)

Can be caused by previous cardiac surg, radiation, TB.

Also often idiopathic.

Question 22

Constrictive pericarditis s/s

Answer 22

Similar to Tamponade - JVD may be more prevalent and less likely to see pulsus paradoxus with constrictive pericardiditis

1. Incerased CVP, RAP, PCWP
2. decreased CO
3. Fatigue
4. Atrial dysrhythmias (a-fib/a-flutter)
5. Edema
6. Ascites and Hepatomegaly

(there is often ventricular disonence with both tamonade and constrictive pericardidit - I think this is a 3rd degree block)

Question 23

Tx for constrictive pericarditis

Answer 23

Pericardiectomy- removal of adherent/fibrous pericardium

• often high blood loss
• cardiac dysrhythmias in theis surgery ususally due to mechaneical compression of the heart

Question 24

Bonus- What are the pKas for Lidocaine, Bupivacaine, and Chloroprocaine?

Answer 24

• Lidocaine 7.9
• Bupivacaine 8.1
• Chloroprocaine 8.7 (but still fast onset time…)

(The Closer to 7.4 the faster the onset in general)

Question 25

Explain Acute pericardiditis after an MI

Answer 25

1. Occurs in 10-15% of patients
2. Usually develops 1-3 days post MI
3. It is usaually due to a transmural MI- it is a result of an interaction between healing necrotic myocardial tissue with the pericardium.

Question 26

Definition of Cardiac Tamponade

Answer 26

1. Can occur any time fluid collects in the pericardial sac and is under pressure
2. Tamponade exists when there is an increase in pressure that IMPAIRS diasolic filling of the heart
   
   1. Increased CVP

Question 27

Drugs to use and avoid in a patient getting a pericardiocentesis. Why?

Answer 27

1. Use: Ketamine - wnat to maintain SNS outflow!!!
   
   1. also can do under local
   2. can induce with benzos, fentanyl, nitrous oxide - (if an exploration is being done prep patient with drapes prior to induction and keep sitting upuntil ready to start!)
   3. Pancuronium = stimulates ganglion→good to keep HR up
2. DO NOT USE: Propofol!!!!!
3. Want to avoid GA and positive pressure ventilation becasue it can casue life threatening hypotension

Question 28

What should be anticipated once the couse of cardiac tamponade is releived?

Answer 28

1. Expect a significant swing in BP from hypotensive to hypertensive
2. Must be prepared to treat - especially if the cause of tamonade is due to aortic hematoma, aortic disection or aneurism

Question 29

Anesthetic Management for Constrictive pericarditis

Answer 29

Minimize Changes! To everything!

• Maintain HR, Preload SVR and contractility
• Usually getting a pericardiectomy - removal of adherent pericardium
  
  • Often high blood loss
  • Maintain volume with fluid and replace blood loss!!!
  • Have blood ready
• AVOID bradycardia - CO dependent on HR
• They will tolerate a moderate increase in HR
• Drugs that can be used
  
  • ketamine
  • etomidate
  • pancuronium
  • sympathomimetics
• Intraop cardiac arrythmias are usually from mechanical compression of the heart
• Large-bore IVs, CVP, A-line