UBP 5.1 (Short Form): CV - CIED & Open Globe Injury

Question 1

What are your concerns when considering this patient for surgery?

(A 68-year-old, 145 kg male presents to the operating suite for simultaneous repair of an open fracture of the right radius and an open globe injury of his right eye. Both injuries occurred during a fall while in his kitchen. He recalls finishing supper and standing to take his plate to the sink and then waking up on the floor having broken his arm and injured his eye. His medical history includes hypertension, insulin dependent diabetes mellitus, and sick sinus syndrome; his medications include propranolol, HCTZ, and metformin. He is awake and alert with the following vital signs: HR = 76; BP = 154/90 mmHg; T = 36.5 C)

Answer 1

I have multiple concerns in considering this patient for surgery, such as the risk for further complications such as –

1. vascular or nerve damage with further manipulation of the injured arm;
2. neurologic injury secondary to head injury, elevated ICP, trauma to his cervical spine, or contributory factors such as hypoxia, hypercarbia, hypotension, and/or anemia;
3. difficult airway management (i.e., obesity, head trauma);
4. extrusion of the ocular contents of his right eye;
5. aspiration (full stomach, pain, diabetes),
6. fat embolism (long bone fracture), and
7. significant hypotension or hypertension (hypertensive patient, blood pressure medications, possible hypovolemia, possible diabetic autonomic neuropathy).
8. Finally, I would be concerned about – Factors that may have caused or contributed to his fall, including –
   
   • bradycardia (sick sinus syndrome),
   • pacemaker failure (if he has one),
   • myocardial ischemia (diabetes, obesity, and hypertension),
   • an arrhythmia other than bradycardia, stroke (hypertension), or
   • hypovolemia and orthostatic hypotension (possibly secondary to overaggressive control of blood pressure, diabetic autonomic neuropathy, medication error, and/or inadequate fluid intake).
9. If the patient had a pacemaker (due to sick sinus syndrome), I would also be concerned about – Identifying the type of device,
10. whether the patient is dependent on the device’s antibradycardia pacing function, the
11. need for perioperative reprogramming, and
12. whether it was functioning properly.

Question 2

He tells you that his implanted pacemaker was upgraded to an automatic implantable cardioverter-defibrillator (AICD) 1 year ago when he began to experience episodes of ventricular tachycardia. He hands you a card that identifies this AICD as VVE-DDDRO.

What information does this code give you?

(A 68-year-old, 145 kg male presents to the operating suite for simultaneous repair of an open fracture of the right radius and an open globe injury of his right eye. Both injuries occurred during a fall while in his kitchen. He recalls finishing supper and standing to take his plate to the sink and then waking up on the floor having broken his arm and injured his eye. His medical history includes hypertension, insulin dependent diabetes mellitus, and sick sinus syndrome; his medications include propranolol, HCTZ, and metformin. He is awake and alert with the following vital signs: HR = 76; BP = 154/90 mmHg; T = 36.5 C)

Answer 2

This form of ICD code provides the most complete description of the device and informs me that this patient’s device is capable of ventricular shock (VVE-DDDRO),

ventricular antitachycardia pacing (VVE-DDDRO),

electrogram detection (VVE-DDDRO),

atrioventricular pacing (VVE-DDDRO),

atrioventricular sensing (VVE-DDDRO),

a triggered or inhibited response to sensing (VVE-DDDRO), and

rate responsiveness (VVE-DDDRO).

The last letter indicates that this device is NOT capable of multisite pacing (VVE-DDDRO).

This code represents a combination of the pacemaker (NGB) and defibrillator (NBD) codes, with the 4th letter of the defibrillator code (which normally indicates the antibradycardia pacing chambers) replaced by the full pacemaker code.

Question 3

How would you evaluate the patient’s AICD (cardiac implantable device = CIED) preoperatively?

(A 68-year-old, 145 kg male presents to the operating suite for simultaneous repair of an open fracture of the right radius and an open globe injury of his right eye. Both injuries occurred during a fall while in his kitchen. He recalls finishing supper and standing to take his plate to the sink and then waking up on the floor having broken his arm and injured his eye. His medical history includes hypertension, insulin dependent diabetes mellitus, and sick sinus syndrome; his medications include propranolol, HCTZ, and metformin. He is awake and alert with the following vital signs: HR = 76; BP = 154/90 mmHg; T = 36.5 C)

Answer 3

In evaluating this patient’s AICD, I would identify and consult the persons who normally manage this patient’s device (i.e. cardiologist and/or CIED management team) to determine:

1. the indication for placement,
2. the model and type of the device
3. whether the patient was pacemaker dependent,
4. the programmed pacing mode and any special programming,
5. the behavior of the device when exposed to a magnet (usually disables tachydysrhythmia detection and therapy),
6. the number, types, and age of leads (leads placed < 3 months prior are more likely to be dislodged during central line placement, cardiac surgery, or with the manipulation of intracardiac catheters),
7. the battery status (should be at least 3 months, due to the potentially increased sensitivity of the generator to damage from electromagnetic interference),
8. the last generator test date,
9. the patient’s underlying rhythm and rate,
10. the presence of any alert status on the generator or lead (i.e. a threatened lead failure that could result in oversensing), and
11. the date of the last documented pacing threshold with an adequate safety margin (stimulus output is usually 2-3 times pacing threshold).

Question 4

The orthopedic surgeon says he will need to use electrocautery. Does this concern you?

(A 68-year-old, 145 kg male presents to the operating suite for simultaneous repair of an open fracture of the right radius and an open globe injury of his right eye. Both injuries occurred during a fall while in his kitchen. He recalls finishing supper and standing to take his plate to the sink and then waking up on the floor having broken his arm and injured his eye. His medical history includes hypertension, insulin dependent diabetes mellitus, and sick sinus syndrome; his medications include propranolol, HCTZ, and metformin. He is awake and alert with the following vital signs: HR = 76; BP = 154/90 mmHg; T = 36.5 C)

Answer 4

I am concerned about the potential complications associated with electrocautery such as –

burns to operating personnel or the patient, which usually occur due to improper application of the electrosurgical return plate (i.e. inadequate electrolyte gel, disconnected return wire, or incomplete contact of the return plate with the patient).

Moreover, I am concerned about the potential complications associated with the use of electrocautery in patients with an AICD (a.k.a. cardiac implantable electronic device or CIED), such as –

inhibition of pacing function

(Note: If the pacemaker is not programmed to asynchronous mode, electromagnetic interference from the electrosurgical unit may be interpreted as intrinsic heart activity, thus inhibiting pacing),

reprogramming of the AICD,

triggering of tachydysrhythmia treatment, microshock, and internal damage to the device.

Therefore, to reduce the risk to this patient, I would:

1. recommend the use of an ultrasonic harmonic scalpel or bipolar electrocautery forceps (the two blades of the electrocautery forceps act as the active and return electrodes, making it unnecessary to apply a remote return plate) to reduce electromagnetic interference (EMI);
2. ensure the availability of temporary pacing and defibrillation equipment;
3. disable tachydysrhythmia detection and therapy (the risk of EMI is higher given the location of the surgery above the umbilicus); and, if I determined that the patient was pacemaker dependent,
4. set the device to asynchronous pacing via reprogramming (while magnet placement may set a simple pacemaker to asynchronous pacing, it will not set the pacing function of an AICD to asynchronous pacing).

Question 5

The surgeon says that he will need to use a monopolar electrosurgical unit (ESU).

How can you minimize the risk of interference with the AICD?

(A 68-year-old, 145 kg male presents to the operating suite for simultaneous repair of an open fracture of the right radius and an open globe injury of his right eye. Both injuries occurred during a fall while in his kitchen. He recalls finishing supper and standing to take his plate to the sink and then waking up on the floor having broken his arm and injured his eye. His medical history includes hypertension, insulin dependent diabetes mellitus, and sick sinus syndrome; his medications include propranolol, HCTZ, and metformin. He is awake and alert with the following vital signs: HR = 76; BP = 154/90 mmHg; T = 36.5 C)

Answer 5

To minimize the risk to this patient, I would:

1. ensure proper electrosurgical unit (ESU) function;
2. place the return plate as close to the operative site (possibly the ipsilateral shoulder) and as far from the cardiac implantable electronic device (CIED) as possible to avoid the passage of current through the pulse generator or leads (the goal is to keep the presumed path of the current at least 6 inches away from the CIED);
3. ensure proper application of the return plate (complete contact with the patient and adequate electrolyte gel);
4. require preoperative reprogramming to set the device to asynchronous pacing and to disable tachydysrhythmia sensing and treatment;
5. limit the use of electrocautery as much as possible;
6. use short, intermittent, and irregular bursts at the lowest feasible energy levels when electrocautery is required;
7. verify adequate perfusion with continuous monitoring of an arterial pulse wave (pulse oximetry); and
8. ensure the availability of temporary pacing and defibrillation equipment.

Question 6

You determine that the patient is pacemaker dependent.

Would you require that the device be interrogated prior to surgery?

(A 68-year-old, 145 kg male presents to the operating suite for simultaneous repair of an open fracture of the right radius and an open globe injury of his right eye. Both injuries occurred during a fall while in his kitchen. He recalls finishing supper and standing to take his plate to the sink and then waking up on the floor having broken his arm and injured his eye. His medical history includes hypertension, insulin dependent diabetes mellitus, and sick sinus syndrome; his medications include propranolol, HCTZ, and metformin. He is awake and alert with the following vital signs: HR = 76; BP = 154/90 mmHg; T = 36.5 C)

Answer 6

If the surgery could reasonably be delayed for the necessary amount of time, I would.

Normally, in a stable patient who does not have intervening medical problems that might adversely affect the function of the CIED, I would be comfortable proceeding without interrogating the device preoperatively as long as his AICD had been checked within the last 6 months

(RECOMMENDATION: implantable cardioverter-defibrillators should ideally be checked within last 6 months, and pacemakers within the last 12 months).

However, since this patient’s recent loss of consciousness may have been due to pacemaker failure, I would REQUIRE preoperative interrogation to ensure proper function.

Interrogation of the device can provide a great deal of helpful information including – battery life, lead integrity, programmable settings, pacemaker dependency, intrinsic rhythm, the effects of magnet application, sensing and pacing thresholds, and recorded arrhythmic events.

Considering the increased risk for EMI (i.e. use of monopolar cautery for surgery above the umbilicus), I would also ask the CIED management team to disable tachydysrhythmia detection and therapy.

Moreover, I would ask that this pacemaker dependent patient’s device be programmed for asynchronous pacing (DOO).

Finally, recognizing that rate-responsive programming can lead to faster than expected pacing rates, I would ask that all rate responsive sensors be disabled.

Question 7

The surgeon says, “We need to operate. Can’t we just put a magnet over it?”

(A 68-year-old, 145 kg male presents to the operating suite for simultaneous repair of an open fracture of the right radius and an open globe injury of his right eye. Both injuries occurred during a fall while in his kitchen. He recalls finishing supper and standing to take his plate to the sink and then waking up on the floor having broken his arm and injured his eye. His medical history includes hypertension, insulin dependent diabetes mellitus, and sick sinus syndrome; his medications include propranolol, HCTZ, and metformin. He is awake and alert with the following vital signs: HR = 76; BP = 154/90 mmHg; T = 36.5 C)

Answer 7

I would not just “put a magnet over it” because magnet placement does not reliably disable tachydysrhythmia sensing and treatment (some devices are programmed to ignore magnet placement or have had their magnet function disabled permanently).

Moreover, the application of a magnet does NOT affect the pacing mode of an AICD (does not revert the device to asynchronous pacing), placing this pacemaker dependent patient at risk of inappropriate pacing inhibition during electrocautery use.

A magnet could be used to disable the tachydysrhythmia sensing and treatment if the urgency of the case did not allow for preoperative programming and interrogation.

However, the risks of proceeding without reprogramming would have to be carefully weighed against the risks of delaying the procedure, especially when using a monopolar ESU for surgery above the umbilicus (increased risk for EMI) on a patient who is pacemaker dependent and who’s AICD has rate responsive programming.

Clinical Note:

• Magnetic placement sets most pacemakers to asynchronous mode, but does not affect the pacing mode of implantable cardioverter-defibrillators (ICDs).
• Magnetic placement does, however, disable the tachydysrhythmia sensing and treatment of most ICDs.

Question 8

The pacemaker representative sets the device to asynchronous pacing and disables the rate responsiveness function.

He recommends using a magnet to disable the antitachycardia shock and pacing capabilities of the AICD.

Do you agree with this recommendation to use a magnet in place of reprogramming?

(A 68-year-old, 145 kg male presents to the operating suite for simultaneous repair of an open fracture of the right radius and an open globe injury of his right eye. Both injuries occurred during a fall while in his kitchen. He recalls finishing supper and standing to take his plate to the sink and then waking up on the floor having broken his arm and injured his eye. His medical history includes hypertension, insulin dependent diabetes mellitus, and sick sinus syndrome; his medications include propranolol, HCTZ, and metformin. He is awake and alert with the following vital signs: HR = 76; BP = 154/90 mmHg; T = 36.5 C)

Answer 8

Assuming that the magnet’s positioning and effects (disabling of tachydysrhythmia sensing and treatment) were verified preoperatively and that I could reliably secure the magnet to prevent shifting out of place, I would be ok with this recommendation.

Using a magnet provides the additional advantage of quickly resuming tachydysrhythmia sensing and treatment by removal of the magnet in the event of intraoperative ventricular tachycardia/fibrillation (this effect should also be verified preoperatively).

Question 9

Would you administer any preoperative medications?

(A 68-year-old, 145 kg male presents to the operating suite for simultaneous repair of an open fracture of the right radius and an open globe injury of his right eye. Both injuries occurred during a fall while in his kitchen. He recalls finishing supper and standing to take his plate to the sink and then waking up on the floor having broken his arm and injured his eye. His medical history includes hypertension, insulin dependent diabetes mellitus, and sick sinus syndrome; his medications include propranolol, HCTZ, and metformin. He is awake and alert with the following vital signs: HR = 76; BP = 154/90 mmHg; T = 36.5 C)

Answer 9

I would administer:

1. metoclopramide and an H2-receptor antagonist to reduce the risk of aspiration pneumonitis (full stomach, pain, and diabetes);
2. carefully titrated narcotics and benzodiazepines to reduce pain and anxiety, which could lead to hypertension and increased risk for extrusion of ocular contents (over-sedation must be avoided because the hypoxia and hypercapnia associated with hypoventilation would increase the risk of extrusion of ocular contents); and
3. atropine or glycopyrrolate to reduce oral secretions and facilitate the airway management of this obese patient at risk for aspiration (the use of atropine to inhibit the oculocardiac reflex is unnecessary with a properly functioning pacemaker in the asynchronous mode).