UBP 3.2 (Long Form): Neuro – Acute Cervical Spinal Cord Injury

Question 1

Intra-Operative Management:

What are your positioning concerns?

• (A 51-year-old, 81 kg, man who was recently in a motor vehicle accident, is transferred from the trauma suite to the operating room for surgical decompression and immobilization of the cervical spine in the prone position. He is stable, has a c-collar in place, is intubated, and has received pancuronium for neuromuscular blockade. Furthermore, he has two large-bore peripheral intravenous lines, an arterial line, a central line, and a Foley catheter in place.*
• PMHx: The patient’s medical history is significant for hypertension, asthma, GERD, coronary artery disease, and hypercholesterolemia. He has never experienced a heart attack, but did have a drug-eluting stent placed 6 months ago.*
• Meds: Plavix, Lipitor, Advair, and albuterol*
• Allergies: NKDA*
• PE: Vital Signs: P = 54, BP = 102/62 mmHg, T = 37.0 °C, Weight = 81 kg*
• Ventilator Settings: (SIMV) TV = 700, R = 10, Pressure Support = 5*
• Airway: Intubated with 7.5 ETT; on ventilator*
• Lungs: Clear to auscultation, bilaterally*
• Cardiovascular: Regular rate and rhythm*
• Labs: Hgb = 9.1 gm/dL*
• CT: C5 fracture)*

Answer 1

I have several concerns about this patient with head and neck injury being in the prone position, including:

1. additional spinal cord injury, secondary to inadequate neck stabilization during transport and initial positioning;
2. pressure-induced injury to the eyes, ears, nose, breasts, genitals, knees, and toes;
3. position-related obstruction of venous drainage leading to increased intracranial and intraocular pressure, placing him at increased risk for cerebral ischemia and post-operative vision loss; and
4. brachial plexus injury secondary to compression of the axillary sheath or abduction of the arms by more than 90 degrees.

• Clinical Note:*
• The prolonged immobility associated with chronic spinal cord injury can lead to osteoporosis, increasing the risk for pathologic fractures when moving or positioning the patient (not yet a concern for this patient with acute spinal cord injury)

Question 2

Intra-Operative Management:

You just get the patient positioned when the resident, who was filling one of the vaporizers, spills an entire bottle of volatile agent on the floor.

What would you do?

• (A 51-year-old, 81 kg, man who was recently in a motor vehicle accident, is transferred from the trauma suite to the operating room for surgical decompression and immobilization of the cervical spine in the prone position. He is stable, has a c-collar in place, is intubated, and has received pancuronium for neuromuscular blockade. Furthermore, he has two large-bore peripheral intravenous lines, an arterial line, a central line, and a Foley catheter in place.*
• PMHx: The patient’s medical history is significant for hypertension, asthma, GERD, coronary artery disease, and hypercholesterolemia. He has never experienced a heart attack, but did have a drug-eluting stent placed 6 months ago.*
• Meds: Plavix, Lipitor, Advair, and albuterol*
• Allergies: NKDA*
• PE: Vital Signs: P = 54, BP = 102/62 mmHg, T = 37.0 °C, Weight = 81 kg*
• Ventilator Settings: (SIMV) TV = 700, R = 10, Pressure Support = 5*
• Airway: Intubated with 7.5 ETT; on ventilator*
• Lungs: Clear to auscultation, bilaterally*
• Cardiovascular: Regular rate and rhythm*
• Labs: Hgb = 9.1 gm/dL*
• CT: C5 fracture)*

Answer 2

Given the size of the spill and the risk of significant exposure of the operating room personnel to evaporating volatile agent (the patient is intubated and isolated from the evaporating agent), I would –

immediately have someone suction the spilled volatile agent into a plastic container, seal and label the container, and transport it to the appropriate waste disposal site (i.e. waste disposal company or medical waste incinerator).

At the same time, I would verify the patient was securely positioned on the bed, ensure adequate sedation and neuromuscular blockade, and prepare him for transport on the operating room bed to the nearest anesthetizing location (i.e. 100% oxygen, rescue drugs, appropriate monitoring).

Question 3

Intra-Operative Management:

Postoperatively, an ENT surgeon is consulted to evaluate the patient’s facial injuries.

He tells you he would like to schedule surgery in the next couple of weeks to address the injuries.

What would you say?

• (A 51-year-old, 81 kg, man who was recently in a motor vehicle accident, is transferred from the trauma suite to the operating room for surgical decompression and immobilization of the cervical spine in the prone position. He is stable, has a c-collar in place, is intubated, and has received pancuronium for neuromuscular blockade. Furthermore, he has two large-bore peripheral intravenous lines, an arterial line, a central line, and a Foley catheter in place.*
• PMHx: The patient’s medical history is significant for hypertension, asthma, GERD, coronary artery disease, and hypercholesterolemia. He has never experienced a heart attack, but did have a drug-eluting stent placed 6 months ago.*
• Meds: Plavix, Lipitor, Advair, and albuterol*
• Allergies: NKDA*
• PE: Vital Signs: P = 54, BP = 102/62 mmHg, T = 37.0 °C, Weight = 81 kg*
• Ventilator Settings: (SIMV) TV = 700, R = 10, Pressure Support = 5*
• Airway: Intubated with 7.5 ETT; on ventilator*
• Lungs: Clear to auscultation, bilaterally*
• Cardiovascular: Regular rate and rhythm*
• Labs: Hgb = 9.1 gm/dL*
• CT: C5 fracture)*

Answer 3

I would begin by discussing the urgency of the procedure with the ENT surgeon, assuming this were an elective procedure that could potentially be postponed, there would be several issues that should be considered, such as –

• the type of coronary stent that was placed six months ago,
• his hemodynamic stability (is he still in spinal shock?), and
• the risk of autonomic hyperreflexia (assuming spinal shock had resolved).

In the case of persistent spinal shock, any elective procedure should be postponed until the resolution of this condition and its associated hemodynamic instability.

If it were determined that he had a drug eluting stent (as suggested by the fact that he is still taking Plavix), then he should not be scheduled for any elective surgery that required the discontinuation of his clopidogrel (Plavix) until at least 12 months following stent placement.

Undergoing a procedure that required the discontinuation of his clopidogrel would place him at considerable risk because, following the placement of a drug eluting stent, the incidence of late stent thrombosis is significantly increased with the premature discontinuation of thienopyridine therapy within the first year.

Moreover, the inherent hypercoagulable state associated with surgery places the patient at additional risk of thrombosis.

Clinical Note:

• Elective procedures should be delayed for 2-4 weeks following balloon angioplasty to allow for complete healing of any vessel injury.
• When a stent is placed, elective procedures for which there is significant risk of bleeding should be delayed for at least 4-6 weeks following bare metal stent placement (BMS) and for at least 12 months following drug eluting stent (DES) placement.
• (ACC/AHA Guidelines - 2007; AHA/ACC/SCAI/ACS/ADA Science Advisory - 2007)

Question 4

Post-Operative Management:

Six months later this same patient presents to your operating room for repair of an open compound fracture of his right femur.

He is quadriplegic, but able to maintain adequate respiratory function without support.

His medications include baclofen, plavix, lipitor, advair, and albuterol.

What would you consider in your preoperative workup?

• (A 51-year-old, 81 kg, man who was recently in a motor vehicle accident, is transferred from the trauma suite to the operating room for surgical decompression and immobilization of the cervical spine in the prone position. He is stable, has a c-collar in place, is intubated, and has received pancuronium for neuromuscular blockade. Furthermore, he has two large-bore peripheral intravenous lines, an arterial line, a central line, and a Foley catheter in place.*
• PMHx: The patient’s medical history is significant for hypertension, asthma, GERD, coronary artery disease, and hypercholesterolemia. He has never experienced a heart attack, but did have a drug-eluting stent placed 6 months ago.*
• Meds: Plavix, Lipitor, Advair, and albuterol*
• Allergies: NKDA*
• PE: Vital Signs: P = 54, BP = 102/62 mmHg, T = 37.0 °C, Weight = 81 kg*
• Ventilator Settings: (SIMV) TV = 700, R = 10, Pressure Support = 5*
• Airway: Intubated with 7.5 ETT; on ventilator*
• Lungs: Clear to auscultation, bilaterally*
• Cardiovascular: Regular rate and rhythm*
• Labs: Hgb = 9.1 gm/dL*
• CT: C5 fracture)*

Answer 4

In addition to evaluating and optimizing his coronary artery disease and asthmatic condition,

I would –

• ask about recent food ingestion
  
  • (emergent case),
• ensure the availability of short acting vasodilators,
• make sure his baclofen therapy is continued throughout the perioperative period
  
  • (abrupt cessation can lead to seizures),
• provide aspiration prophylaxis
  
  • (high spinal cord lesion, pain, GERD, and possible recent food ingestion), and
• carefully evaluate the patient for the various complications associated with cervical spinal cord injury, such as:
  
  1. autonomic hyperreflexia, which occurs with the return of spinal cord reflexes below the level of injury (occurs with spinal cord lesions above the level of T7);
  2. pulmonary dysfunction, secondary to –
     
     • impaired diaphragmatic function (denervation and/or elevation of the diaphragm secondary to fecal impaction),
     • chronic pulmonary infections (impaired ability to cough and clear secretions), and
     • denervation of the intercostal and abdominal muscles;
  3. renal dysfunction, secondary to –
     
     • recurrent calculi,
     • amyloid deposition, and
     • chronic urinary tract infections (inability to completely empty the bladder);
  4. altered thermoregulation (increased susceptibility to hypothermia due to chronic vasodilation and absence of normal reflex cutaneous vasoconstriction);
  5. anemia;
  6. cardiac conduction abnormalities, secondary to autonomic dysfunction and/or electrolyte abnormalities;
  7. decreased neck range of motion, which may affect airway management;
  8. additional bone fractures, (these patients often develop osteoporosis secondary to prolonged immobility); and
  9. decubitus ulcers and deep venous thrombosis, secondary to immobility.

To this end, I would –

• review the most current neck films,
• perform a careful history and physical exam, and
• order an EKG, CXR, pulmonary function tests, blood urea nitrogen, creatinine, arterial blood gases, hematocrit, and electrolytes.

Question 5

Post-Operative Management:

Due to his spinal cord injury, the man does not experience pain in his lower extremities.

Knowing this, the surgeon requests mild sedation for the case.

Would you agree to this request?

• (A 51-year-old, 81 kg, man who was recently in a motor vehicle accident, is transferred from the trauma suite to the operating room for surgical decompression and immobilization of the cervical spine in the prone position. He is stable, has a c-collar in place, is intubated, and has received pancuronium for neuromuscular blockade. Furthermore, he has two large-bore peripheral intravenous lines, an arterial line, a central line, and a Foley catheter in place.*
• PMHx: The patient’s medical history is significant for hypertension, asthma, GERD, coronary artery disease, and hypercholesterolemia. He has never experienced a heart attack, but did have a drug-eluting stent placed 6 months ago.*
• Meds: Plavix, Lipitor, Advair, and albuterol*
• Allergies: NKDA*
• PE: Vital Signs: P = 54, BP = 102/62 mmHg, T = 37.0 °C, Weight = 81 kg*
• Ventilator Settings: (SIMV) TV = 700, R = 10, Pressure Support = 5*
• Airway: Intubated with 7.5 ETT; on ventilator*
• Lungs: Clear to auscultation, bilaterally*
• Cardiovascular: Regular rate and rhythm*
• Labs: Hgb = 9.1 gm/dL*
• CT: C5 fracture)*

Answer 5

I would not agree to sedation for this case due to the risks of pulmonary aspiration and autonomic hyperreflexia.

The gastrointestinal paralysis associated with high spinal cord injury and/or significant pain (open femur fracture), combined with possible recent food ingestion (emergent case), place this patient at increased risk for pulmonary aspiration.

Moreover, assuming the resolution of spinal shock and the return of spinal reflexes, this patient would be at increased risk for autonomic hyperreflexia with visceral distention (i.e. bladder) and/or any noxious stimuli below the level of injury, despite the lack of pain perception.

Therefore, assuming there were no contraindications, I would perform neuraxial, regional, or general for this case in order to minimize the risk of aspiration and autonomic hyperreflexia (the latter is best prevented by spinal, regional, or general anesthesia).

Question 6

Post-Operative Management:

The patient requests spinal anesthesia.

Would you agree?

• (A 51-year-old, 81 kg, man who was recently in a motor vehicle accident, is transferred from the trauma suite to the operating room for surgical decompression and immobilization of the cervical spine in the prone position. He is stable, has a c-collar in place, is intubated, and has received pancuronium for neuromuscular blockade. Furthermore, he has two large-bore peripheral intravenous lines, an arterial line, a central line, and a Foley catheter in place.*
• PMHx: The patient’s medical history is significant for hypertension, asthma, GERD, coronary artery disease, and hypercholesterolemia. He has never experienced a heart attack, but did have a drug-eluting stent placed 6 months ago.*
• Meds: Plavix, Lipitor, Advair, and albuterol*
• Allergies: NKDA*
• PE: Vital Signs: P = 54, BP = 102/62 mmHg, T = 37.0 °C, Weight = 81 kg*
• Ventilator Settings: (SIMV) TV = 700, R = 10, Pressure Support = 5*
• Airway: Intubated with 7.5 ETT; on ventilator*
• Lungs: Clear to auscultation, bilaterally*
• Cardiovascular: Regular rate and rhythm*
• Labs: Hgb = 9.1 gm/dL*
• CT: C5 fracture)*

Answer 6

Assuming he had discontinued his Plavix (clopidogrel) at least 7 days prior, (antiplatelet therapy is often continued for a year following the placement of a drug-eluting stent),

I would agree to spinal anesthesia, recognizing that both spinal anesthesia and deep general anesthesia suppress the unmodulated reflex sympathetic stimulation that can lead to autonomic hyeprreflexia.

Furthermore, neuraxial anesthesia would provide adequate analgesia, while avoiding the need for airway instrumentation of this patient with moderate asthma who is at risk for aspiration.

Question 7

Post-Operative Management:

You discover that the patient has yet to discontinue his Plavix, making a general anesthetic necessary.

Would you perform rapid sequence intubation using succinylcholine?

• (A 51-year-old, 81 kg, man who was recently in a motor vehicle accident, is transferred from the trauma suite to the operating room for surgical decompression and immobilization of the cervical spine in the prone position. He is stable, has a c-collar in place, is intubated, and has received pancuronium for neuromuscular blockade. Furthermore, he has two large-bore peripheral intravenous lines, an arterial line, a central line, and a Foley catheter in place.*
• PMHx: The patient’s medical history is significant for hypertension, asthma, GERD, coronary artery disease, and hypercholesterolemia. He has never experienced a heart attack, but did have a drug-eluting stent placed 6 months ago.*
• Meds: Plavix, Lipitor, Advair, and albuterol*
• Allergies: NKDA*
• PE: Vital Signs: P = 54, BP = 102/62 mmHg, T = 37.0 °C, Weight = 81 kg*
• Ventilator Settings: (SIMV) TV = 700, R = 10, Pressure Support = 5*
• Airway: Intubated with 7.5 ETT; on ventilator*
• Lungs: Clear to auscultation, bilaterally*
• Cardiovascular: Regular rate and rhythm*
• Labs: Hgb = 9.1 gm/dL*
• CT: C5 fracture)*

Answer 7

While the risk of succinylcholine-induced hyperkalemia is reduced by 6 months following spinal cord injury (the highest risk is between 4 weeks and 5 months),

I would prefer to avoid using this depolarizing muscle relaxant any time between 24 hours and one year following the injury.

Moreover, given his moderate asthma, I would be concerned that the unreliable depth of anesthesia associated with a rapid sequence induction would place him at increased risk for bronchospasm.

However, recognizing this patient is at increased risk for pulmonary aspiration (high spinal cord injury → gastrointestinal paralysis; pain → delayed gastric emptying; emergent case → possible recent food ingestion), I would take precautions to reduce this risk as much as possible.

Therefore, I would:

1. optimize his asthmatic condition by providing a B2-agonist;
2. administer an H2-receptor antagonist and a non-particulate antacid;
3. place him in reverse-trendelenburg position, to facilitate intubation and reduce the risk of passive regurgitation;
4. apply cricoid pressure;
5. perform a slow controlled induction, with the goal of achieving an adequate depth of anesthesia to prevent bronchospasm;
6. administer Rocuronium to provide optimal intubation conditions;
7. secure his airway with an appropriately sized endotracheal tube; and
8. decompress his stomach with a nasogastric tube following intubation.

Question 8

Post-Operative Management:

The case has just started, when you are informed that the central oxygen supply is compromised.

What would you do?

• (A 51-year-old, 81 kg, man who was recently in a motor vehicle accident, is transferred from the trauma suite to the operating room for surgical decompression and immobilization of the cervical spine in the prone position. He is stable, has a c-collar in place, is intubated, and has received pancuronium for neuromuscular blockade. Furthermore, he has two large-bore peripheral intravenous lines, an arterial line, a central line, and a Foley catheter in place.*
• PMHx: The patient’s medical history is significant for hypertension, asthma, GERD, coronary artery disease, and hypercholesterolemia. He has never experienced a heart attack, but did have a drug-eluting stent placed 6 months ago.*
• Meds: Plavix, Lipitor, Advair, and albuterol*
• Allergies: NKDA*
• PE: Vital Signs: P = 54, BP = 102/62 mmHg, T = 37.0 °C, Weight = 81 kg*
• Ventilator Settings: (SIMV) TV = 700, R = 10, Pressure Support = 5*
• Airway: Intubated with 7.5 ETT; on ventilator*
• Lungs: Clear to auscultation, bilaterally*
• Cardiovascular: Regular rate and rhythm*
• Labs: Hgb = 9.1 gm/dL*
• CT: C5 fracture)*

Answer 8

Given the risk of administering a hypoxic gas mixture,

I would

• immediately switch to the backup oxygen cylinders,
• disconnect the main pipeline supply,
• hand ventilate with low gas flow rates (Pneumatically driven mechanical ventilators use significantly more oxygen than hand ventilation at low gas flow rates. Many newer machines use air rather than oxygen for pneumatic power, making this step unnecessary.),
• calculate the approximate amount of time before the oxygen cylinders are depleted, and
• have someone locate additional oxygen E-cylinders in case they are required.

It is important to disconnect the main pipeline supply to prevent the machine from preferentially using the main pipeline supply (50 psig), rather than the lower-pressure (45 psig) backup oxygen cylinder.

• Clinical Note:*
• Method of Estimating Oxygen E-Cylinder Supply Time*
• Approximate Re**maining Time (hours):
  
  • Oxygen Cylinder Pressure (psig) / [200 x Oxygen Flow Rate (L/min)]

Question 9

Post-Operative Management:

You are using oxygen cylinders for the case.

Two hours into the procedure, the patient’s blood pressure increases to 205/106 mmHg, and his heart rate decreases to 42 beats per minute.

What would you do?

• (A 51-year-old, 81 kg, man who was recently in a motor vehicle accident, is transferred from the trauma suite to the operating room for surgical decompression and immobilization of the cervical spine in the prone position. He is stable, has a c-collar in place, is intubated, and has received pancuronium for neuromuscular blockade. Furthermore, he has two large-bore peripheral intravenous lines, an arterial line, a central line, and a Foley catheter in place.*
• PMHx: The patient’s medical history is significant for hypertension, asthma, GERD, coronary artery disease, and hypercholesterolemia. He has never experienced a heart attack, but did have a drug-eluting stent placed 6 months ago.*
• Meds: Plavix, Lipitor, Advair, and albuterol*
• Allergies: NKDA*
• PE: Vital Signs: P = 54, BP = 102/62 mmHg, T = 37.0 °C, Weight = 81 kg*
• Ventilator Settings: (SIMV) TV = 700, R = 10, Pressure Support = 5*
• Airway: Intubated with 7.5 ETT; on ventilator*
• Lungs: Clear to auscultation, bilaterally*
• Cardiovascular: Regular rate and rhythm*
• Labs: Hgb = 9.1 gm/dL*
• CT: C5 fracture)*

Answer 9

Recognizing that the development of hypertension and bradycardia in this paraplegic patient with a high spinal cord lesion is consistent with autonomic hyperreflexia (AH), and that bladder distention or some other stimulus below the level of the spinal cord transection is the likely cause of his hypertension and bradycardia, I would:

1. ask the surgeon to discontinue any unnecessary stimulation,
2. deepen the anesthetic,
3. administer a direct acting vasodilator (i.e. sodium nitroprusside),
4. ensure that the bladder is emptying appropriately (i.e. check the Foley catheter and urine output),
5. place an arterial line for continuous blood pressure monitoring, and
6. monitor the patient closely for subsequent complications, such as –
   
   • cerebral, retinal, or subarachnoid hemorrhage;
   • seizures;
   • myocardial ischemia;
   • dysrhythmias; and
   • pulmonary edema (left ventricular failure due to increased afterload).

Question 10

Post-Operative Management:

You discover that the Foley catheter had been obstructed.

What is the pathophysiology of autonomic hyperreflexia (AH)?

• (A 51-year-old, 81 kg, man who was recently in a motor vehicle accident, is transferred from the trauma suite to the operating room for surgical decompression and immobilization of the cervical spine in the prone position. He is stable, has a c-collar in place, is intubated, and has received pancuronium for neuromuscular blockade. Furthermore, he has two large-bore peripheral intravenous lines, an arterial line, a central line, and a Foley catheter in place.*
• PMHx: The patient’s medical history is significant for hypertension, asthma, GERD, coronary artery disease, and hypercholesterolemia. He has never experienced a heart attack, but did have a drug-eluting stent placed 6 months ago.*
• Meds: Plavix, Lipitor, Advair, and albuterol*
• Allergies: NKDA*
• PE: Vital Signs: P = 54, BP = 102/62 mmHg, T = 37.0 °C, Weight = 81 kg*
• Ventilator Settings: (SIMV) TV = 700, R = 10, Pressure Support = 5*
• Airway: Intubated with 7.5 ETT; on ventilator*
• Lungs: Clear to auscultation, bilaterally*
• Cardiovascular: Regular rate and rhythm*
• Labs: Hgb = 9.1 gm/dL*
• CT: C5 fracture)*

Answer 10

Cutaneous (pain) or visceral (i.e. bladder or rectal distention) stimulus below the level of spinal cord injury results in a reflex sympathetic discharge.

Because the area of the body below the transection is neurologically isolated, the sympathetic activity in this area is NOT modulated by inhibitory impulses from higher central nervous system centers.

This unopposed sympathetic activity leads to vasoconstriction below the level of the lesion, with reflex vasodilation above the level of the lesion.

When the lesion is above T7, vasodilation above the lesion is insufficient to prevent systemic hypertension, which then stimulates carotid sinus receptors, leading to reflex bradycardia.