UBP 4.8 (Long Form): CV -- Cardiac Ablation

Question 1

Intra-operative Management:

Why do you think the patient has tricuspid regurgitation?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm²; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 1

This patient’s moderate tricuspid regurgitation is most likely secondary to –

• rheumatic disease and/or the pulmonary hypertension that has most likely developed as a result of her mitral valve stenosis
• (other potential causes include – infective endocarditis, carcinoid syndrome, tricuspid valve prolapse, and Ebstein’s anomaly).

The restriction of flow through the stenotic mitral valve leads to increased left atrial pressures, which are then transmitted to the pulmonary circulation.

Over time, chronically elevated pressures in the pulmonary circulation result in pulmonary vascular changes that lead to the development of irreversible pulmonary hypertension, right ventricular pressure overload, compensatory right ventricular hypertrophy, and, eventually, right ventricular dilation.

Finally, significant dilation of the right ventricle can lead to tricuspid regurgitation (also pulmonary valve regurgitation).

Question 2

Intra-operative Management:

How does this patient’s tricuspid regurgitation affect your anesthetic management?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 2

Considering this patient’s moderate tricuspid regurgitation, I would –

seek to AVOID conditions that lead to –

decreased preload and/or increased right ventricular afterload, such as –

• hypovolemia (decreased preload),
• decreased systemic vascular resistance (decreased preload),
• hypoxia (increased pulmonary artery pressure),
• hypercarbia (increased pulmonary artery pressure),
• acidosis (increased pulmonary pressure), and
• tachycardia (impaired left ventricular filling and increased left atrial pressures lead to increased right ventricular afterload).

Additionally, I would: –

1. avoid nitrous oxide, which could exacerbate pulmonary hypertension;
2. ensure that any air in the intravenous lines is removed, recognizing that elevated right atrial pressures and decreased left sided filling pressures place this patient at increased risk for right-to-left shunting through a patent foramen ovale;
3. monitor central venous pressures to guide fluid administration, monitor right ventricular function, and detect changes in regurgitant volume; and
4. avoid excessive airway pressures during mechanical ventilation (i.e. PEEP, high mean airway pressures), which could lead to increased afterload and decreased preload.

Question 3

Intra-operative Management:

Woul you place a pulmonary artery catheter for this case?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 3

Given her mitral valve stenosis and tricuspid regurgitation, utilizing a pulmonary artery catheter to monitor pulmonary artery pressure (right ventricular afterload), cardiac output, and systemic vascular resistance may prove valuable in guiding fluid therapy, ensuring adequate preload, and maintaining cardiac output.

However, given

• the inaccuracies in pulmonary artery data associated with tricuspid regurgitation and mitral valve stenosis,
• the difficulty of passing the catheter through the regurgitant tricuspid valve (due to interference from the regurgitant wave), and
• the increased risk of massive hemorrhage in the settting of pulmonary hypertension (increased risk of pulmonary artery rupture) and
• an elevated INR (normal = 0.9-1.2),

I would NOT employ this method of monitoring for this patient.

If a pulmonary artery catheter were used, it would be important to recognize that, in the setting of mitral valve stenosis and tricuspid regurgitation,

1. the pulmonary capillary wedge pressure would OVERestimate the left ventricular diastolic pressure (LVDP) by at least the amount of the mitral valve gradient;
2. tachycardia and elevated cardiac output increase the mitral valve pressure gradient, leading to an increasing difference between the estimated and actual LVDP; and
3. thermodilution cardiac output measurements are inaccurate (falsely elevated), due to a portion of the cold injectate moving retrograde into the atrium rather than into the pulmonary artery.

Question 4

Intra-operative Management:

Would you provide general anesthesia or MAC for this case?

What are the advantages of general anesthesia?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 4

Given the importance of maintaining adequate preload in this patient with mitral valve stenosis and tricuspid regurgitation, I would prefer to perform this case under – MAC – to avoid the potential reduction in systemic vascular resistance that often occurs when general anesthesia is administered to a chronically hypertensive patient.

However, considering her increased risk for aspiration (history of GERD and diabetes), and the potentially detrimental effects of tachycardia in the setting of mitral valve stenosis,

I would ensure – adequate analgesia, to avoid tachycardia and minimize sedative requirements (increasing levels of sedation lead to increased risk of impaired airway reflexes).

While catheter ablations are commonly performed under MAC or deep sedation, there are certain advantages to performing the procedure under general anesthesia, such as –

• patient comfort during a long procedure,
• better blunting of sympathetic stimulation (avoiding tachycardia is very important in patients with mitral valve stenosis),
• control of the airway and ventilaton (may help to avoid hypercarbia, which can increase pulmonary vascular resistance), and
• the option for immediate surgical intervention should a complication occur.

Question 5

Intra-operative Management:

The patient refuses MAC. How would you induce this patient?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 5

Given the importance of –

• avoiding tachycardia and decreased systemic vascular resistance in a patient with mitral valve stenosis,
• the potential for difficult airway management (obesity, decreased cervical range of motion), and
• her significant right-sided weakness (possible proliferation of extrajunctional receptors placing her at risk for significant hyperkalemia),

I would: –

1. ensure the presence of the difficult airway cart;
2. provide aspiration prophylaxis;
3. place the patient in the sniff position (avoid reverse-trendelenburg positioning so as not to exacerbate any reductions in preload);
4. preoxygenate with 100% oxygen;
5. administer lidocaine and fentanyl to reduce risk of a sympathetic response to laryngoscopy;
6. apply cricoid pressure;
7. perform gentle laryngoscopy; and
8. secure the airway as quickly as possible.

While a rapid sequence induction would normally be a desirable method of induction in a patient with a full stomach, I would AVOID it for this patient due to – the risk of hemodynamic instability (i.e. reduced systemic vascular resistance and preload), inadequate depth of anesthesia (to prevent tachycardia), and succinylcholine-induced hyperkalemia.

Question 6

Intra-operative Management:

After intubation, the heart rate increases to 210 bpm.

Are you concerned?

What would you do?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 6

I would be concerned with a heart rate of 210 bpm

since tachycardia decreases coronary perfusion while increasing myocardial oxygen demand and left ventricular wall tension,

placing this patient with several risk factors for coronary artery disease at increased risk for myocardial ischemia.

Moreover, in the setting of mitral valve stenosis, tachycardia results in decreased left ventricular filling (decreased time for diastolic filling), increased left atrial pressure, and, possibly, pulmonary edema and congestive heart failure.

Therefore, I would –

• confirm the cardiac rate and rhythm on the EKG,
• cycle the blood pressure cuff,
• ensure adequate oxygenation and ventilation,
• palpate the patient’s pulse, and
• administer diltiazem to control the ventricular rate.

Since her ventricular rate is greater than 150 beats/min, I would begin chest compressions and perform synchronized cardioversion using 100 joules and progressing to 200 joules, 300 joules, and 360 joules as necessary to convert the patient to a sinus rhythm.

Question 7

Intra-operative Management:

Would you consider administering a B-blocker?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 7

While B-blockers are often used for rate control in atrial fibrillation,

they should NOT be combined with calcium channel blockers due to the risk for severe cardiac depression.

This would be of particular concern in this patient with signs of right heart strain (EKG and tricuspid regurgitation).

Question 8

Intra-operative Management:

In the case of an unstable patient requiring DC cardioversion, would you require synchronized shocks?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 8

While synchronization of direct-current shocks with the R-wave is desirable to prevent a shock being delivered during the vulnerable period of ventricular repolarization,

I would NOT require synchronization in the case of an unstable patient,

recognizing that synchronization is of unproven benefit and could result in delayed treatment.

Question 9

Intra-operative Management:

The patient’s condition is stabilized and the case continues. During electrophysiologic mapping the blood pressure suddenly drops to 44/21.

What do you think is the cause?

What would you do?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 9

Acute hemodynamic instability during electrophysiologic mapping is usually the result of –

• a cardiac arrhythmia such as ventricular tachycardia or fibrillation.

However, I would also consider other potential causes related to this procedure and the patient’s comorbidities, such as –

• myocardial ischemia,
• acute heart failure,
• cardiac tamponade,
• cardiac rupture,
• undiagnosed hemorrhage,
• pulmonary embolism,
• and acute air embolism.
• Moreover, if a central line were placed, I would consider the possibility of tension pneumothorax.

In managing this situation, I would –

• immediately inform the surgeon,
• discontinue any volatile agent,
• evaluate the EKG,
• palpate the pulse,
• auscultate the chest,
• ensure adequate oxygenation,
• place the patient in the trendelenburg position (to increase preload), and
• administer fluids, vasopressors, and inotropes as indicated.

While treating her, I would keep in mind that arrhythmia-induced or reflex tachycardia limits the ventricular filling time in patients with mitral valve stenosis, potentially exacerbating her condition.

If my initial interventions were ineffective, I would consider obtaining an echocardiogram and chest x-ray to identify the problem and guide therapy (a pulmonary artery catheter would potentially prove helpful, but would be associated with the risks previously discussed).

Question 10

Intra-operative Management:

Despite your interventions the blood pressure does not improve.

The surgeon performs fluoroscopy, which shows the ablation catheter curled in the left chest.

What would you do?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 10

Recognizing that this is consistent with cardiac rupture, I would:

1. ask the cardiologist to inform the operating room of the emergent case and consult a cardiovascular surgeon for emergency repair;
2. begin fluid resuscitation;
3. prepare for massive blood transfusion (i.e. initiate protocol, ensure blood typing, adequate intravenous access);
4. administer vasopressors as indicated; and
5. place an arterial line and TEE to guide therapy.

If there were evidence of cardiac tamponade (diastolic collapse of the right atrium, right ventricle, and/or left ventricle, as determined by TEE, is the most sensitive and specific sign of cardiac tamponade), I would ask the surgeon to decompress the pericardium.

Question 11

Post-operative Management:

Assuming the patient underwent successful catheter ablation without any complications.

Woud you discharge the patient home?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 11

Since cardiac ablation is commonly done as an outpatient procedure,

I would discharge her to home once she met the “Safe Discharge” criteria, which include:

1. stable vital signs;
2. controlled nausea and vomiting;
3. the absence of unexpected bleeding from the operative site;
4. adequate pain control with oral analgesics;
5. an ability to walk without dizziness;
6. the provision of discharge instructions (written and verbal) and prescriptions;
7. patient acceptance of discharge; and
8. a responsible escort.

Another commonly utilized set of criteria are those included in the Post-Anesthetic Discharge Scoring System (PADSS), where a score of 9 or higher is considered adequate for safe discharge to home.

PADSS:

Category // Description of Status // PADSS Score:

Vital Signs:

• Within 20% of preoperative baseline = 2
• Within 20% to 40% of preoperative baseline = 1
• >40% of preoperative baseline = 0

Activity Level:

• Steady gait, no dizziness, consistent with preoperative level = 2
• Ambulates with assistance = 1
• Unable to ambulate = 0

Nausea & Vomiting:

• Minimal: mild, no treatment required = 2
• Moderate: treatment effective = 1
• Severe: treatment not effective = 0

Pain: (VAS = Visual Analog Scale)

• VAS = 0-3; minimal to no pain before discharge = 2
• VAS = 4-6; moderate pain = 1
• VAS = 7-10; severe pain = 0

Surgical bleeding:

• Minimal: no dressing changes required = 2
• Moderate bleeding: 1-2 dressing changes with no additional bleeding = 1
• Severe bleeding: 3 or more dressing changes and continued bleeding = 0

Question 12

Post-operative Management:

The postop nurse reports that the patient has met discharge criteria, but has been unable to voide her bladder. Would you allow her to be discharged?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 12

While urinary retention can lead to bladder atony and permanently impaired voiding,

it is NO longer considered a necessary condition for safe discharge in patients considered at low risk for developing urinary retention,

where the incidence of this complication is around 1%.

Therefore, I would discharge this patient home as long as she met the appropriate criteria.

However, for patients who are at higher risk for developing urinary retention (i.e. pelvic surgery; personal or family history of retention; spinal cord disease; neuraxial anesthesia with long-acting agents; or neuraxial anesthesia with a combination of opioids and local anesthetics),

I would require voiding with a residual volume of less than 400 mL (best determined by ultrasound).

Moreover, if the patient’s bladder volume were greater than 500 mL, I would perform catheterization to empty the bladder.

Note: Oral intake is also no longer required for safe discharge due to evidence suggesting

less nausea in children and no change in outcome (i.e. no increased/decreased nausea and vomiting or prolonged hospital stay) in adults who do not receive oral fluids prior to discharge.

Question 13

Post-operative Management:

The nurse informs you that she just discovered the patient did not arrange for someone to escort her home. What would you do?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 13

Recognizing that lack of sleep, surgical stress, and residual anesthetic effects may impair her driving performance for up to 24 hours

(impairment is most significant in the first 2 hours after surgery; some surgical procedures, such as lower limb surgery, are associated with prolonged impairment of driving performance),

I would explain my concerns to the patient, attempt to find her an appropriate escort, and, if unsuccessful, arrange for hospital admission.

Ideally, the lack of an escort would have been identified prior to the administration of an anesthetic, at which point an elective case would have been cancelled unless the appropriate arrangements were made.

Question 14

Post-operative Management:

20 minutes after surgery the recovery room nurse calls to inform you that the patient is having severe postoperative nausea and vomiting (PONV).

What would you do?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 14

I would first go and evaluate the patient,

check a blood glucose level,

ensure adequate pain control,

oxygenation,

fluid administration and hemodynamic stability.

If the PONV were not related to a more serious condition, I would initiate therapy, keeping in mind that it is NOT recommended to repeat any drugs used for prophylaxis or treatment during the first 6 hours following initial administration.

Assuming no prophylacitc antiemetics were administered, I would start by giving ondansetron (treatment dose is 1/4th of prophylactic dose; 1 mg) and providing supplemental oxygen.

If she remained nauseous, I would administer a drug from a different class, such as droperidol or promethazine.

If these were also inadequate, i would administer 20 mg of propofol as needed.

I would avoid the use of steroids in this diabetic patient, recognizing that steroid administration may result in hyperglycemia.

Clinical Note: It is recommended that dexamethasone administration not be repeated more often than every 8 hours (unlike droperidol and 5-HT3 antagonists, which may be repeated every 6 hours).

Question 15

Post-operative Management:

What are the risk factors for PONV?

• (A 58-year-old, 82 kg, female with chronic atrial fibrillation is scheduled for elective electrophysiologic mapping and catheter ablation. She developed A-fib 4 years ago and has been refractory to standard medical therapy. She reports an episode of palpitations and syncope 3 weeks ago.*
• PMHx: GERD, HTN, Type II DM, Osteoarthritis, CVA with residual right-sided weakness;*
• Meds: Diltiazem, coumadin, HCTZ, metformin, naproxen, prilosec, multivitamin*
• Allergies: NKDA*
• PE: Vital Signs: Wt = 82 kg; BP = 152/89 mmHg; HR = 92; RR = 18; T = 36.8 C;*
• General: Significant right-sided weakness; unable to ambulate*
• Airway: Mallampati II; thyromental distance = 6 cm, decreased cervical ROM*
• Heart: Irregular rhythm; split S1; loud S2; rumbling diastolic murmur best heard at the apex;*
• Lungs: CTAB*
• Labs: Hgb 14 gm/dL; Hct 41%; K = 4.1 mEq/L; INR = 1.4; BUN/Cr = 18/1.0; potassium = 3.8 mmol/L; magnesium = 2.1 mmol/L*
• EKG: Atrial fibrillation, right heart strain*
• Echocardiogram: mitral valve area = 1.1 cm2; dilated left atrium without thrombus; moderate tricuspid regurgitation)*

Answer 15

Risk factors for PONV can be divided into three types:

• patient risk factors,
• anesthetic/procedural risk factors, and
• postoperative risk factors.

Patient-specific risk factors include – Female gender, Nonsmoking status, Anxiety, and a history of PONV or motion sickness.

Anesthetic risk factors include – the use of volatile anesthetics, nitrous oxide, neostigmine, and/or intraoperative and postoperative opioids.

Surgical risk factors include – the length and type of surgery, with laparoscopy, ENT, neurosurgery, breast, strabismus, laparotomy, and plastic surgery

considered to be high risk for PONV.