Case 28 - Parathyroidectomy Flashcards

1
Q

What is the physiology of calcium regulation?

A

Vitamin D

  • absorption of Ca2+ from GI

PTH

  • absorption of Ca2+ from bone, intestines, vit D production, decrease renal excretion

Calcitonin (produced by thyroid)

  • decrease Ca2+ plasma concentrations

Ca2+

  • ionized Ca = active and free form
  • alkalosis –> increases binding of Ca2+ to albumin –> decrease ionized plasma conc
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2
Q

clinical features of hypercalcemia?

A

Bones, stones, groans, and psych overtones

Muscukloskeletal (bones)

  • weak/atrophy
  • bone fx

Renal (stones)

  • kidney stones / polyuria

GI (Groans)

  • n/v
  • abd pain / stomach ulcer
  • pancreatitis
  • constipation

CNS (psych overtones)

  • seizures
  • disorientation
  • altered mental status
  • lethardy/sedation

Cards

  • htn
  • conduction abnormalities / arrhythmias
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3
Q

how do you treat hypercalcemia?

A
  • stop administration of calcium (limit intake)
  • 0.9% NS administration
  • diuresis with furosemide
    • do not give thiazide diuretics –> they save calcium in renal tubules –> increase levels
  • consider dialysis (if patient has pre-existing renal failure or CHF)
    • CHF can be exacerbated with fluid administration
  • bisphosphonates (pamidronate)
    • tx for ​life threatening hpercalcemia
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4
Q

what are pre-op anesthetic considerations for parathyroidectomy?

A
  • fluid management
    • life threatening hypercalemia requires fluid admin
      • at risk for hypervolemia, CHF**​
  • diuretic use
    • risk of hypokalemia
  • muscle relaxation
    • hypercalcemia antagonizes muscle relaxation (need frequent dosing)
  • conduction abnormal / arrhythmias
  • parathyroid hyperplasia assoc with MEN (MEN 2 involves pheochromocytoma)
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5
Q

are there important aspects to consider during anesthetic managment for a patient undergoing parathyroidectomy?

A

general anes straightforward

1) muscle relaxation vs intraop nerve monitoring

  • consider opioid infusions to maintain relaxation
    • benefits of opioids: provides deeper anesthesia, depress laryngeal reflexes –> avoid coughing during surgery and emergence
    • coughing can cause neck hematoma

2) frequent lab draw for PTH levels

  • PTH half life of 5 minutes
  • frequent intraop lab draws to assess surgical success (low PTH = successful surgery, correct gland excised)
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6
Q

What regional anesthesia technique could you use for parathyoridectomy?

A

superficial and deep cervical plexus block

  • superficial = sensory to surgical site
  • deep = motor to surgical site
    • risks: vertebral A. injection, phrenic nerve paralysis, neck hematoma, epidural or subdural block
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7
Q

what are the complications of parathyroidecotmy?

A

similar to thyroidectomy - complications resulting in respiratory distress

Resp Distress

  • recurrently laryngel N. injury (uni vs b/l)
  • neck hematoma
  • tracheomalacia
  • Hypocalacemia - laryngeal muscle tetany
    • occurs 24-72 hours after surgery

Other complications

  • coagulopathy
  • neuromuscular irritability
    • muscle cramps
    • chvostek’s sign (facial n irritability) /trousseau’s sign (carpal spasm)
  • paresthesia
  • CNS
    • psychosis
    • seziures
      *
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