Musculoskeletal Flashcards
What drugs may potentially cause the onset of SLE?
- hydralazine
- procainamide
- isoniazid
- methyldopa
- ppl who are slow acetylators are at higher risk
What physiologic stressors can exacerbate SLE?
- Surgery
- infection
- pregnancy
- poor fetal outcomes if mother has HTN and nephritis
What are the systemic problems with SLE?
(picture)
How is mild SLE treated?
- NSAIDS for joint symptoms and pleurisy
- must stop 2 days before surgery (bleeding)
- low dose corticosteroids such as prednisone
- for thrombocytopenia, hemolytic anemia, skin, arthritis symptoms
- antimilarial drugs (hydroxychloroquine/quinacrine) and
How is severe SLE treated?
- High dose steroids
- this means you will probably need to give them a stress dose in the OR
- immunosuppressive chemotherapy drugs
- methotrexate
- vincristine
Why does somebody who has been taking steroids require a stress dose of steroids for surgery?
- Exogenous steroids prevent ppl from releasing cortisol when they encounter a stressor
- As the stress of the surgery increases because the surgery is more major, you can give higher stress dose of hydrocortisone
What are airway management considerations for SLE?
- There may be laryngeal involvement
- leryngeal erythema and edema common
- cricoarytenoid arthritis
- mucosal ulceration
- recurrent laryngeal nerve palsy
What do you need to consider when selecting anesthetic drugs for a pt with SLE?
- Interactions with drugs used for SLE treatment
- degree of organ dysfunction
- impaired renal
- hepatic clearance
- cardiopulmonary involvement
What can you do to further reduce infections in pts with SLE?
Why is this a particular concern?
- Strict asepsis technique with invasive procedures
- maintain normothermia
- help reduce infection
- lessen impact of Raynaud’s if present
- SLE patients are usually on immunosupressant medications
What anesthetic agents are best for SLE pts?
What should be avoided?
- IA- do not depend of kidney for elimination
- propofol and Etomidate are not significantly affected by renal impairment
- Midaz ok in low doses
-
Opioids accumulate and prolong respiratory depression
- sz with accumulation of meperidine
What are the cardiac manifestations of Rheumatoid arthritis?
- dysrhythmia from rheumatoid nodules in the cardiac conduction system
- cardiac valve fibrosis
- pericarditis
- myocarditis
- coronary artery arteritis (similar to CAD, risk of MI)
- Dilation of aortic root- aortic regurgitation
What are the pulmonary manifestations of Rheumatoid arthritis?
- Pleural effusion and restrictive lung disease due to rheumatoid nodules in the lung tissue
- decreased lung volume
- pulmonary fibrosis (rare)
What are common surgical treatments for Rheumatoid arthritis?
- Tendon release procedure, synovectomy, joint replacement
- releive pain and restore joint function
What should you be aware of when managing the airway of a pt with rheumatoid arthritis?
- document pre-op ROM limits, baseline symptoms of pain, numbness, and weakness
- get MRI of neck
- consider awake fiberoptic intubation
- TMJ may affect mouth opening and cervical spine mobility, decreasing
- Fixation/arthritis of cricoarytenoid joints:
- voice changes or hoarseness
- can make glottic opening difficult to identify or stenotic
- require decreased tube size
- edema may cause post-op airway obstruction
- C-spine risk of Atlantoaxial subluxation
What is significant regarding the Cspine in patients with Rheumatoid arthritis?
How can this be determined?
- Risk for Atlantoaxial subluxation (AAS)
- The distance between anterior arch of the atlas to odontoid process (Dens) is > 3 mm on radiologic imaging
- risk of slipping off
- occurs in 25% of severe rheumatoid patients
- risk of cervical spinal cord/medulla compression and interference with vertebral artery blood flow
- need to be very careful when positioning for intubation (determine acceptable positions while pt is awake)
Anesthesia management of Rheumatoid arthritis
- Anemia with cronic disease
- effects of medications on platelet function
- If pt has lung disease:
- pre-op PFT, intraop ABG, post op ventilatory support
- may need stress dose of corticosteroids
- extubate with caution in those with cricoarytenoid arthritis
- may want to have another intubation setup ready
Anesthetic conditions for pts with osteoarthritis
positioning
PMMA
- positioning
- support affected joints
- position to minimize risk of injury
- reconstructive surgeries use bone “cement” (PMMA)
- space filler that holds the implant agains the bone
- causes high pressures, pushes things into the blood, causing small emboli of fat and marrow
- be prepared for drop in pressures
- hypoxia, hypotension, dysrhythmias, PHTN, decreased CO
Osteo arthritis anesthetic considerations concering pheumatic tourniquets
- Provide a bloodless field that greatly facilitates surgery
- inflation pressure usually 100 mmhg over pts systolic blood pressure
- prolonged inflation (>2hr) causes pain, nerve, damage
- be careful not to treat this pain with too much opioids b/c it will be gone instantly when the turnequet is released
- deflation may cause hemodynamic changes
- can have them release slowly over time
- notify physician that it has been on longer than 2hrs and document that
Which muscles are most affected by myesthenia gravis?
- muscles innervated by cranial nerves
- ocular
- pharyngeal
- laryngeal
What should you consider pre-operatively with a pt with myasthenia gravis?
- Look at dose of pyridostigmine
- assess pulmonary lung function
- try to ease pt’s stress (psychologic and physical)
What is the rate of occurance of myesthenia gravis in men and women?
- 1:7,500
- women aged 20-30
- men > 60yrs
What are the clinical features of myesthenia gravis?
presentation?
most affected muscles
cardiac involvement?
- Presentation varies from mild weakness of limited muscle groups to severe weakness of multiple muscle groups
- Class I- ocular MG
- Class IV- severe, generalized MG
- Ocular muscles are most commonly affected
- Ptosis, dysphagia, and diplopia
- Bulbar (brainstem)/laryngeal and pharyngeal muscle weakness
- difficulty clearing secretions, pulm aspiration
- myocarditis possible
- a fib, heart block, cardiomyopathy
- Severe disease associated with asymmetrical proximal muscle weakness (w/o atrophy)
- Neck, shoulders, respiratory muscles
What are the treatments for myesthenia gravis?
- Oral anticholinesterase, maybe with steroid therapy
- PO pyrostigmine
- Corticosteroids- prednisone limits antibody production (second line therapy)
- Thymectomy (median sternotomy or mediastinoscopy
- Plasmapheresis- removes antibodies during crisis
- depletes plasma esterase levels
- prolonged effect of succ, mivacurium, ester-linked LAs
What medications would you minimize or avoid in a myesthenia gravis pt?
- benzos, opioids b/c pt is prone to weakness
- aminoglycoside antibiotics can enhance weakness
How would you plan to induce a pt with Myesthenia gravis?
- Use short-acting agents (propofol)
- Consider intubation without muscle paralysis
- deep IA may be sufficient
- topical lidocaine
- NDMB potency increased 2x, reduce dose 33-50% if using
- Aspiration risk- consider RSI
- may increase Succ dose to 2 mg/kg to overcome resistance (anticipate prolonged effect)
- if succ is used, NO NDMR until muscle function has returned and no fade present
- do not give fasiculating dose
If giving a NDMR to a pt with myesthenia gravis, where should you place the PNS?
Orbicularis oculi
How should you provide the maintenance anesthesia to a pt with myesthenia gravis?
- deep anesthesia with a volatile agent can provide sufficient relaxation for many surgical procedures
What are some considerationf for emergence for a pt with myesthenia gravis?
- They are at great risk for postoperative respiratory failure
- advise pt that they may wake up with an ETT in place
- Carefully evaluate ventilatory function prior to extubation
- >5s head lift is a safe predictor
- close observation in recovery
What is Myasthenic syndrom?
What is it’s other name?
- Lambert-Eaton myasthenic syndrome (LEMS)
- pt presents with proximal muscle weakness
- Usually develops in association with a neoplasm, but is also seen with other cancers or idiopathic autoimmune
- often with small cell carcinoma of the lung
- IgG antibodies form against the presynaptic voltage gate Ca++ channels
- decreased release of ACh
- If tumor is present, these antibodies are directed at the tumor but cross-react with the Ca++ channels
Will an anticholinesterase help to reverse clinical effects of an NDMR in a patient with Myasthenic syndrome?
- No! because ACh is not getting released from the vesicles, so there isnt any in the NMJ
Difference between myesthenic syndrome and myesthenia gravis
(chart)
What characterizes Duchenne’s muscular dystrophy?
- symmetric proximal muscle weakness manifesting in gait disturbance
- Kyphoscoliosis results from progressive weakness and contractures
- weakness pronounced in proximal extremities
- wheelchair bound by age 8-10, fatal by 20
- cardiopulmonary dysfunction
- degeneration of cardiac muscle
- chronic weakness of inspiratory muscles (diff. clearing secretions)
- reduced intestinal tract tone
- decreased gastric emptying and increased aspiration risk
why don’t you give Succ to kids?
- because some kids have undiagnosed muscular dystrophy
- When succ is given to somebody with muscular dystrophy, they can have severe rhabdomyalasis
- can cause life threatening K levels
- have of pts with MD who receive succ do not survive
What clinical changes will you see in a pt with muscular dystrophy because of the cardiac muscle degeneration?
- ECG abnormalities
- atrial arrhythmias
- prolonged P-R interval
- decreased myocardial contractility and cardiomyoathy
- mitral regurgitation from papillary muscle dysfunction
- NEED CARDIAC WORKUP PRE-OPERATIVELY
- EKG
What clinical changes will you see in muscular dystrophy patients regarding pulmonary function?
- Progressive respiratory muscle weakness
- inadequate cough
- frequent pulmonary infections
- Kyphoscoliosis and muscle degeneration lead to a severe restrictive disease pattern
- Sleep apnea is common
Why is sleep apnea such a big deal?
- Oxygen levels plumet, SNS kicks into fight or flight
- all night long
- pulmonary vasculature is exposed to low O2 levels
- this causes vasoconstriction
- this leads to pulmonary hypertension
- These pts tend to be RSI
What should you give to a muscular dystrophe patient preoperatively?
- Avoid pre-op sedation or opioids
- Give aspiration prophylaxis
- antacid with H2 blocker or PPI
- metoclopramide to reduce volume
- antisialogogue like glyco
How should you induce a pt with muscular dystrophy?
- NO SUCCINYLCHOLINE!!
- risk of inducing severe hyperkalemia, rhabdo, v-fib, cardiac arrest
- MH
What should you consider regarding maintenance anesthesia for a patient with muscular dystrophy?
- they may have marked cardiopulmonary depression with IA
- Normal or prolonged response to NDMR
- anticipate post-op pulmonary dysfunction
- prepare pt/family for possible ICU after surgery
- Regional anesthesia may be preferable
How is Marfan’s Syndrome treated?
- Beta blockers are standard of care
- reduce workload of the heart
- delay/prevent AA and disection
- Surgical procedures
- elective aortic repair- recommended when the largest part of the aortic diameter is 4.5 cm
- Spinal fusion for scoliosis
What are anesthetic considerations for Marfan’s Syndrome?
- focus pre-op assessment on cardiac abnormalities
- Airway
- visualization of larynx fine even with high arched palate and crowded teeth
- TMJ dislocation risk because of joint laxity
- tracheomalacia- floppy tracheal cartilage leading to tracheal collapse
- Continuously monitor for pneumothorax
- hemodynamic staility is critical!
Why is it so important to control hemodynamics in pts with Marfan’s syndrome?
how can you do this?
- Prevent sudden increase in myocardial contractility
- this produces and increase in aortic wall tension
- Avoid excessive endogenous catecholamine production
- control pain and anxiety
- treat hypertensive episodes immediately
- VA can decrease the force of cardiac ejection
- decrease the risk of aortic dissection
- Ex: fentanyl and lidocaine before DVL
- heavy propofol
- esmolol to decrease HR
How is Ankylosing spondylitis treated?
- NSAIDS
- exercise, PT
- early diagnosis and treatment is essential to prevent permanent posture and mobility loss
- surgery considered in patients with severe, advanced disease associated with refractory pain and disability
How does ankylosing spondylitis affect management of the airway?
- Difficult intubation if the AS involves the cervical spine
- even more difficult if the TMJ is involved
- limited mouth opening due to TMJ involvement
- Significant risk of neurological injury with any excessive neck extension
- progressive kyphosis and spine fixation may limit intubation
- risk of occult cervical fracture with minimal trauma
- cricoarytenoid arthritis- smaller tube
What cardiac abnormalities are seen in a patient with Ankylosing spondylitis?
How might you anesthetize this patient?
- aortic regurgitation
- avoid sudden increases in SVR/keep HR > 90 and BP low/normal
- conduction abnormalities-BBB
- Cardiomegaly
- More benzos than opioids because opioids decrease HR more
- use glyco with ephedrine to manage HR
- Use etomidate
What pulmonary abnormalities are seen with Ankylosing spondylitis?
- Pulmonary fibrosis
- apical cavity lesions
- pleural thickening (similar to TB)
- decreased compliance of chest wall
- decreased vital capacity
How would you manage the anesthesia for a pt with ankylosing spondylitis?
- Management is influenced by severity of disease
- upper airway involvement
- presence of restrictive lung disease
- degree of cardiac involvement
- may be using neurologic monitors during corrective spinal surgery
- awake fiberoptic tracheal intubation if spinal deformity is extensive
Would you do a spinal or epidural on a pt with ankylosing spondylitis?
- You can, but it is technically very difficult
- may result in an increased risk of complications
- consider paramedian approach
What are surgeries that many patients with achondroplasia will be having done?
- Sub-occipital craniectomy for foramen magnum stenosis
- laminectomy- for spinal stenosis or nerve root compression
- VP shunt- hydrocephalus
- C-sections- required
- cephalopelvic disproportion
- kyphoscoliosis and narrow epidural space make epidurals difficult
- no evidence based dosing guidelines, titrate slowly (weight based)
What are evoked potentials?
What does this mean for the anesthesia you provide?
What is an extra type of access you might want for a surgery with a pt with achondroplasia? Why?
- Right atrial catheter
- needed for a sitting craniectomy for foramen magnum stenosis
- because the patient is sitting, if a vessel gets “nicked”, air can be entrained into the vascular system
- you can remove this air using the right atrial catheter
How do you select the appropriately sized ETT for a child?
- age based: Age/4+4
- weight based: wt (kg)/10+3.5
What kind of cardiac/pulmonary issues would you see in a pt with achondroplasia?
- Central sleep apnea (related to brainstem compression by foramen magnum and upper airway obstruction)
- PHTN leading to cor pulmonale
What are the challenges with airway management associated with achondroplasia?
- Facial features can make mask ventilation difficult
- larynx may be small, making intubation difficult
- have range of tubes and difficult airway cart available
- because of spinal conditions, must avoid hyperextension during intubation
