Spinal Surgery Anesthesia Unit 1 Module 3 Flashcards
What is scoliosis?
Lateral rotation of the spine > 10° with vertebral rotation.
symptoms of adult scoliosis
back pain: arthritis, disc degeneration, spinal stenosis (worse standing)
radiculopathy: pinching of the nerve root at the spinal column
sciatica
What are the effects of thoracic spine scoliosis?
- ↓ Chest wall compliance
- Restrictive lung disease
- ↓ exercise tolerance
Get PFTs!
With thoracic scoliosis, what preop exam can you do to assess for pulmonary HTN
Echo
Normal Values:
○Vt:
○Minute ventilation:
○Functional residual capacity :
○Forced vital capacity
○Forced expiratory volume FEV1:
○Peak Expiratory flow rate :
○Vt: 500 ml
○Minute ventilation: Vt x (# of breaths) 5-10 L
○Functional residual capacity : 3L
○Forced vital capacity 4.5 L
○Forced expiratory volume FEV1: 0.8 or 80&
○Peak Expiratory flow rate : 400-700 L/min
Thoracic scoliosis can lead to chronic _____ secondary to V/Q mismatch
chronic hypoxemia
Increased ____ is common in Thoracic scoliosis, especially with the occurrence of Cor Pulmonale.
pulmonary vascular resistance (PVR)
____ _____ is a condition in which the right side of the heart becomes enlarged and weakened due to increased pressure in the pulmonary arteries.
Cor Pulmonale
What changes to you see on an EKG with an enlarged right ventricle and an enlarged right atrium
right axis deviation:
a large R wave in the right precordial leads (V1 and V2)
and a deep S wave in the left precordial leads: (V5 and V6)
What EKG/cardiac findings might one suspect to find on a scoliosis patient? (Select all that apply)
a. RVH
b. RAE
c. LVH
d. Bi-atrial enlargement
a & b
Corrective surgery for thoracic scholiosis, you expect large blood loss r/t (7)
● Surgical technique
● Operative time
● Number of vertebral levels fused
● Mean arterial pressure (MAP)
○Will be using surgical
hypotension technique
● Platelet abnormalities
● Dilutional coagulopathy
● Primary fibrinolysis
Spinal cord injury:
What muscles would you expect to be affected by a C5 injury?
- Partial diaphragmatic paralaysis
- Deltoids
- Biceps
- Brachialis
- Brachio-radialis
Innervation from (___ - ___) keep the diaphragm alive
C3-C5
What are the hemodynamic consequences of injuries T5 and higher?
Physiologic Sympathectomy
- ↓BP
- ↓HR
- tx midodrine
____ - ____ are the cardiac accelerators
T1-T4
Injuries are higher than T1-T4 and the pt has bradycardia. What medications will you give?
jump straight to epinephrine
anticholinergics like atropine and glycopyrrolate will not work
Autonomic Hyperreflexia is most often seen with complete cord transection above the ____ level.
T5/T6
With automonic hyperreflexia:
below the injury, there is ____
&
above the injury, there is ___
below the injury there is vasoconstriction –> severe transient HTN –> bradycardia & dysrhtyhmias
&
above the injury, there is cutaneous vasodilation
In autonomic hyperreflexia, cutaneous vasodilation is seen _____ the site of injury, whilst cutaneous vasoconstriction is seen ____ the site of injury.
above ; below
What is the basic pathophysiology of Autonomic Dysreflexia?
● Cranial nerve 9 (glossopharyngeal nerve) contributes to bradycardia in autonomic hyperreflexia by carrying sensory information from the carotid sinus baroreceptors to the brainstem, which then triggers a parasympathetic response via the vagus nerve (cranial nerve 10), leading to a decreased heart rate as a compensatory mechanism to the sudden rise in blood pressure associated with autonomic hyperreflexia.
What are the most common causes of Autonomic Dysreflexia?
- Distended bladder/bowel
- Noxious stimuli (think surgical pain)
What is the treatment for Autonomic Dysreflexia?
- Removal of stimulus
- Deepen anesthetic
- Direct-acting Vasodilators
Injury to C3-C5 results in….
Diaphragmatic respiratory failure
Is respiratory function affected by injury to C5-C7?
Yes; impairment of abdominal and intercostal respiratory support
- impairment of expiration