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

Question 1

Intraoperative Management:

Where would you place the electrosurgical current-return pad?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 1

In order to reduce the chance that electromagnetic interference (EMI) from the ESU will interfere with or damage the CIED, I would place the current return pad as close to the operative site and as far from the AICD generator as possible (make sure the current path is at least 6 inches away from the CIED generator).

For this patient undergoing surgery on his head and upper extremity, I would place and ensure the proper application of the return pad on the posterior-superior shoulder contralateral to the site of the generator.

Question 2

Intraoperative Management:

Could you provide regional anesthesia for these procedures?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 2

These procedures could potentially be performed with a right axillary block and an appropriate eye block, such as a retrobulbar block.

However, the placement of a retrobulbar block is associated with an increased risk of extrusion of intraocular contents secondary to pressure generated by the injection of local anesthetics, instrumentation of the orbit, potential bleeding, and/or squeezing of the eyelids due to the pain of injection.

Therefore, any decision to administer regional anesthesia for a penetrating eye injury should be made in consultation with the ophthalmic surgeon.

Question 3

Intraoperative Management:

After consulting with the ophthalmologist, you decide to perform a general anesthetic.

How will you induce the patient?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 3

Assuming his airway exam was reassuring (despite his obesity), I would:

1. administer narcotics and lidocaine to blunt the sympathetic response to laryngoscopy (to avoid extrusion of his intraocular contents);
2. place the patient in the reverse-trendelenburg position to inhibit passive reflux, improve respiratory mechanics, and facilitate rapid intubation (full stomach, obesity, diabetes);
3. administer 100% oxygen for several minutes via gentle facemask application, taking care to avoid mask compression of the injured eye (hypoxia may iniduce a sympathetic response);
4. ensure the availability of difficult airway equipment (obesity, c-collar, possible diabetic stiff joint syndrome);
5. remove the front of the cervical collar to allow for the application of cricoid pressure;
6. apply in-line manual stabilization (cervical spine has yet to be cleared); and
7. ensure adequate neuromuscular blockade with a peripheral nerve stimulator prior to intubating the patient (coughing and bucking could result in the extrusion of intraocular contents).

Question 4

Intraoperative Management:

Would you use succinylcholine?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 4

After pretreatment with a nondepolarizer to blunt the increase in intraocular pressure and prevent muscle fasciculations, I would use succinylcholine for the following reasons:

1. this patient’s full stomach, obesity, and diabetes place him at increased risk of aspiration;
2. the increase in intraocular pressure (1-4 minutes) associated with succinylcholine is relatively minor in comparison to the dramatic increases associated with coughing, bucking, and straining during laryngoscopy with inadequate intubating conditions;
3. appropriate reprogramming of his pacemaker to asynchronous pacing should alleviate any concerns of muscle fasciculation-induced ventricular oversensing and pacing inhibition.

I would keep in mind, however, that pretreatment with a nondepolarizer does not reliably attenuate either the increase in intraocular pressure or muscle fasciculations associated with succinylcholine administration.

Question 5

Intraoperative Management:

How would you induce this patient if no succinylcholine were available?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 5

Assuming succinylcholine was not available and that his airway exam was reassuring,

I would use a nondepolarizer to rapidly secure the airway.

In order to accelerate the onset of action and provide acceptable intubating conditions within 90 seconds, I could administer a high dose of drug, which carries with it the disadvantage of prolonged duration of action (a serious problem with an unrecognized difficult airway).

Alternatively, I could employ a priming technique, where 1/10^th of the nondepolarizer dose is administered 3-4 minutes prior to giving the full dose.

The risk of utilizing the priming strategy in a patient with a full stomach is that partial paralysis may occur prior to administering the full dose, placing the patient at increased risk of aspiration, thereby defeating the purpose of employing this technique in the first place.

Question 6

Intraoperative Management:

Would you place the patient in the trendelenburg position to reduce the risk of aspiration?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 6

Since this obese patient with an open globe injury would likely experience decreased functional residual capacity (decreased time from apnea to desaturation time) and

increased intraocular pressure (secondary to decreased venous drainage of the orbit) in the trendelenburg position, I would avoid this positioning in this particular case.

In general, trendelenburg positioning may be employed during induction to reduce the risk of passive aspiration following the reflux of gastric contents into the oropharynx.

However, this positioning could also facilitate the passive reflux of gastric material into the oropharynx, placing the patient at increased risk for active aspiration (i.e. if the patient maintained some inspiratory effort).

By the same reasoning, some would argue that reverse-trendelenburg positioning reduces the risk of aspiration by inhibiting passive reflux of gastric material.

However, this positioning could facilitate passive aspiration of gastric material that has actively refluxed into the oropharynx (i.e. vomiting or external pressure on the abdomen).

In this case, the reverse-trendelenburg position may be more desirable because it would improve the respiratory mechanics of this obese patient, potentially facilitate rapid intubation, and possibly improve venous drainage from the orbit.

Question 7

Intraoperative Management:

During laryngoscopy the patient vomits and gastric material enters the oropharynx.

Would you now place the patient in the trendelenburg position to reduce the risk of aspiration?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 7

While the trendelenburg position may reduce the risk of aspiration, it may also inhibit venous drainage of the globe, increasing intraocular pressure and placing the injured eye at risk.

Therefore, rather than place the patient in trendelenburg position, I would reduce the pressure I was applying to the cricoid (failure to reduce cricoid pressure risks the generation of sufficient pressure to cause esophageal rupture), suction the patient’s oropharynx, and at the same time level out the bed (assuming it was in the reverse-trendelenburg position) and turn the patient on his side to facilitate the movement of gastric material away from the trachea.

Then, after deepening the anesthetic and ensuring adequate neuromuscular blockade (to prevent further reflex and/or increases in intraocular pressure), I would secure the airway with an endotracheal tube.

While I believe it is important to avoid unnecessary increases in intraocular pressure, my primary goal at this time is to prevent the aspiration of gastric material.

Question 8

Intraoperative Management:

You secure the airway and surgery is proceeding when the patient’s blood pressure drops to 62/38 mmHg.

You note that his pulse rate is 43 beats/minute and that the pacer spikes are not always followed by a QRS complex.

What are you going to do?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 8

This is consistent with failure to capture, which may result secondary to lead failure (the lead delivers insufficient energy to achieve depolarization) or myocardial changes that lengthen the refractory period and/or increase the energy requirement to achieve depolarization.

Therefore, I would:

1. tell the surgeon to stop manipulating the eye and/or using electrocautery, recognizing that, in the setting of pacemaker failure to capture, either could be contributing to the bradycardia via the oculocardiac reflex or pacing inhibition, respectively;
2. deliver 100% oxygen, verify proper endotracheal tube placement, ensure adequate ventilation;
3. auscultate the lungs;
4. administer atropine; and
5. employ transcutaneous pacing. If these measures were unsuccessful, I would
6. start chest compressions and an epinephrine infusion of 1-2 mcg/minute (in the setting of bradycardia, an intravenous bolus of epinephrine should be avoided to prevent excessive tachycardia). At the same time, I would
7. attempt to identify potential causes of his pacemaker’s loss of capture, such as –
   
   • myocardial ischemia, which can significantly increase the energy requirement for depolarization;
   • electrolyte disturbances, such as hypokalemia in this patient taking HCTZ (K+, Ca+, and magnesium abnormalities can all potentially raise the depolarization threshold);
   • acid-base disturbances, which can be caused by or exacerbated by hypoventilation or hyperventilation; and
   • abnormal antiarrhythmic drug levels. If none of these measures were successful, I would
8. consult his cardiologist and
9. consider transvenous pacing or the placement of epicardial leads.

Question 9

Post-operative Management:

You evaluate and treat the patient and his pacemaker begins to capture appropriately.

How would you extubate him?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 9

Since the risk of suture disruption following repair of the eye is minimal even with coughing and bucking, and recognizing that this patient remains at risk of pulmonary aspiration, I would extubate him when he was fully awake.

To achieve a smooth emergence and minimize the patient’s risk of aspiration, I would empty his stomach with an orogastric tube and suction the pharynx while he was still deeply anesthetized, fully reverse any residual neuromuscular blockade, administer 100% oxygen, turn off the volatile agent, administer intravenous lidocaine to prevent coughing during emergence, and extubate the patient only after he regained full consciousness.

Question 10

Post-operative Management:

Does the AICD need to be interrogated postoperatively?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 10

This patient’s device does require interrogation and reprogramming postoperatively in order to –

• reestablish the AICD’s normal pacing function and rate responsive programming;
• ensure the return of ventricular sensing and tachydysrhythmia therapy with removal of the magnet; and
• ensure proper device function.

Ensuring proper functioning is particularly important in this instance due to the device’s temporary failure to capture intraoperatively.

Clinical Note:

• Indications for postoperative interrogation in patients with CIEDs, include:
  
  1. preoperative reprogramming that has left the device nonfunctional;
  2. hemodynamically challenging surgery (i.e. cardiac surgery or significant vascular surgery);
  3. the occurrence of significant intraoperative events, such as cardiac arrest, cardiopulmonary resuscitation, external electrical cardioversion, or the use of temporary pacing;
  4. emergent surgery above the umbilicus, placing the patient at a higher risk for EMI;
  5. cardio-thoracic surgery;
  6. procedures that emit EMI with a greater chance of affecting the device (i.e. external cardioversion, radiofrequency ablation, or therapeutic radiation); and
  7. patient inability to present for device evaluation within 1 month of the procedure.

Question 11

Post-operative Management:

The pacemaker representative is unable to see the patient until the morning.

What will you do?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 11

Given the intraoperative failure to capture and the need to restore normal pacemaker function, ventricular sensing, tachydysrhythmia treatment, and rate responsive programming,

I would keep the patient in a monitored setting until the device could be interrogated and reprogrammed.

Question 12

Post-operative Management:

The post-op nurse calls a code because the patient is experiencing ventricular tachycardia.

You arrive and note that the patient exhibits a wide-complex rhythm.

What are you going to do?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 12

I would:

1. provide supplemental oxygen,
2. check for a pulse,
3. auscultate the chest, and
4. assess his hemodynamic stability. Assuming the patient was stable (no change in mental status, chest pain, hypotension, or signs of shock), I would
5. obtain a 12-lead EKG to help determine if the rhythm is monomorphic, polymorphic, WPW, Torsades, or of uncertain etiology. In the case of wide complex ventricular tachycardia of uncertain etiology, I would
6. further evaluate all 12 leads of the EKG to confirm that the QRS complex was truly wide (>0.12 seconds), look for any signs of atrial activity, and determine if the rhythm is regular or irregular (atrial fibrillation should be considered when the rhythm is irregularly irregular and there are no P waves). Furthermore, given his pre-existing RBBB, I would
7. compare the morphology of the current QRS complexes to those of a previous ECG when he was in sinus rhythm, recognizing that if the QRS morphology is different, the current arrhythmia is most likely ventricular tachycardia rather than supraventricular tachycardia (with SVT and RBBB, the QRS complex would likely be of similar morphology to the previous ECG). Assuming the rhythm was regular and the QRS morphology was different (most likely wider and less organized since ventricular tachycardia originates outside of the conduction system), I would
8. treat this as presumed ventricular tachycardia until proven otherwise (80-90% of regular WCTs with no clear P-waves are VT; the percentage increases to 90-95% when the patient is >50-60 years old and has underlying heart disease, such as prior MI, cardiomyopathy, angina, or heart failure).

To this end, I would:

1. consult a cardiologist and
2. administer adenosine, recognizing that this would convert 5-10% of ventricular tachycardia rhythms, treat paroxysmal supraventricular tachycardia (PSVT), and aid in the diagnosis of other SVTs (by briefly slowing the rate). Furthermore, I would;
3. administer procainamide or amiodarone (amiodarone is preferred in the presence of known impaired left ventricular function), and
4. identify and correct any contributing factors such as hypoxemia, hypovolemia, hypercapnia, hypo/hyperkalemia (taking HCTZ), hypomagnesemia (taking HCTZ), hypothermia, hypoglycemia (diabetic), pulmonary embolism (long bone fracture), and acid-base derangements.

If at any time the patient became unstable despite the presence of a pulse (i.e. unstable due to the fast rate), I would

1. sedate and intubate him and
2. perform immediae synchronized cardioversion (assuming this was monomorphic VT - polymorphic VT is usually unstable and requires unsynchronized shock). In doing this, I would
3. take care to avoid placing the defibrillator paddles directly over the pulse generator since this could result in loss of capture in this pacemaker-dependent patient (secondary to an acute increase in the stimulation threshold).

Question 13

Post-operative Management:

In the setting of an unstable patient, is synchronized or unsynchronized cardioversion better?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 13

Synchronized cardioversion is preferable when a patient has a pulse and is experiencing monomorphic VT due to the increased safety of delivering the shock at a time in the cardiac cycle that avoids the “vulnerable period” (the relatively refractory period near the end of the T-wave), thus reducing the risk of inducing ventricular fibrillation (a synchronized shock is delivered on the R-wave upstroke or the S-wave downslope).

While atrial flutter, monomorphic VT, and atrial fibrillation respond reasonably well to synchronized cardioversion, other arrhythmias, such as polymorphic VT, Torsades, multifocal atrial tachycardia (MAT), junctional tachycardia, and autonomic atrial tachycardia, are unlikely to respond to this intervention.

Therefore, I would only defibrillate (unsynchronized cardioversion) the patient when:

1. synchronized cardioversion were unacceptably delayed for any reason (i.e. improper use of the equipment or failure of the device to synchronize with the patient’s cardiac cycle),
2. synchronized cardioversion precipitated ventricular fibrillation, or
3. the patient was exhibiting an arrhythmia that was unlikely to respond to a synchronized shock (i.e. polymorphic VT, Torsades, multifocal atrial tachycardia (MAT), junctional tachycardia, and automatic atrial tachycardia).

Question 14

Post-operative Management:

You attempt synchronized cardioversion and the patient immediately loses consciousness and a palpable pulse.

What will you do?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 14

Recognizing that the synchronized cardioversion may have precipitated ventricular fibrillation, I would:

1. verify that the patient was truly pulseless;
2. initiate basic life support (30:2 chest compressions to ventilations with 100 compressions per minute);
3. confirm the presence of a shockable rhythm;
4. defibrillate him as quickly as possible (biphasic defibrillator = 120-200 J; AED = 150-200 J; Monophasic = 360 J; the appropriate level of charge is device specific for biphasic defibrillators and AEDs – if the appropriate charge is unknown then use 200 J);
5. resume BLS, intubate (limit attempts to 10 seconds), and ensure adequate intravenous access (the endotracheal tube should only be used for medication administration as a last resort due to less reliable absorption);
6. reconfirm the presence of a shockable rhythm, defibrillate as before, resume chest compressions after defibrillation, and administer epinephrine (1 mg; may repeat every 3-5 minutes) or vasopressin (40 U; a one time dose may be substituted for the 1st or 2nd dose of epinephrine; no repeat dosing is necessary since the duration of action is sufficient for the length of most codes).
7. If his pulseless ventricular tachycardia or ventricular fibrillation persisted, I would – continue chest compressions, epinephrine administration (every 3-5 minutes), and defibrillation (every 2 minutes) until the rhythm changes;
8. administer amiodarone (300 mg; may repeat with 150 mg doses to max of 2,200 mg/24 hours), starting an infusion if the patient’s rhythm converts out of ventricular fibrillation (1 mg/min for 6 hours – then 0.5 mg/min for next 18-72 hours);
9. administer magnesium (1-2 grams) if the patient developed Torsades or if the patient’s potassium or magnesium levels are low (he is taking HCTZ);
10. give lidocaine (1.0-1.5 mg/kg; may repeat every 5-10 minutes with 0.5-0.75 mg/kg up to a total of 3 doses or 3 mg/kg); and
11. administer sodium bicarbonate (1-2 amps) if the arrest persisted longer than 10 minutes and/or his pH < 7.2 despite good ventilation.

Question 15

Post-operative Management:

You are 4 minutes into the code and the patient remains in ventricular fibrillation.

Would you administer bicarbonate?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 15

Recognizing that the administration of sodium bicarbonate may actually worsen intracellular acidosis (despite improved ABG pH values) during the initial stages of the code (initial acidosis is usually respiratory acidosis), I would only administer this medication if:

1. there was preexisting metabolic acidosis,
2. he was hyperkalemic, or
3. if his pH remained low (< 7.2) and he continued to be refractory to treatment despite 5-10 minutes of resuscitation.

Question 16

Post-operative Management:

If his ventricular fibrillation persisted despite several doses of epinephrine, would you consider administering procainamide?

• (A 68-year-old 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 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.*
• PMHx: Hypertension, Sick Sinus Syndrome/Tachycardia - AICD 1 year ago (VVE-DDDRO), Diabetes mellitus - diet controlled*
• Meds: Propranolol, HCTZ, Metformin*
• Allergies: NKDA*
• PE: Vital Signs: HR = 96, BP = 154/90 mmHg, RR = 14, Temp = 36.5 C, Weight = 145 kg, Height = 72 inches*
• General: C-collar in place*
• Airway: Mallampati II*
• Lungs: Clear to auscultation*
• Cardiovascular: RRR*
• Lab: Hgb = 13.8 gm/dL, glucose = 156 mg/dL, K+ = 3.1 mEq/L*
• EKG: Right bundle branch block)*

Answer 16

While procainamide is a first line agent for sustained ventricular tachycardia, it would not be appropriate in the setting of ventricular fibrillation, since it has not proven to be an effective antifibrillatory agent.