Miscellaneous topics 7 Flashcards
Deflation of the pneumatic tourniquet during orthopedic surgery is expected to increase:
a. blood pressure
b. mixed venous oxygen saturation
c. end-tidal carbon dioxide
d. blood pH
c.
______________________ increases intramedullary pressure in the bone and this can produce microemboli that travel to the lungs.
Methyl methacrylate
Methyl methacrylate that produces microemboli that can travel to the lungs can result in
V/Q mismatch and potentiate right heart failure
Residual methyl methacrylate can enter the systemic circulation where it causes
bradycardia, dysrhythmias, systemic hypotension, pulmonary hypertension, hypoxia, and cardiac arrest
Methyl methacrylate entering the systemic circulation is known as
bone cement implantation syndrome (BCIS)
__________ is a recognized complication of long bone trauma
Fat embolism syndrome
The triad of fat embolism syndrome includes
respiratory insufficiency, neurologic changes, and a petechial rash
To reduce the risk of limb ischemia when using a pneumatic tourniquet, the maximum inflation time is
two hours
When used for a bier block, the tourniquet must remain inflated for at least
20 minutes after LA is injected
Premature release of LA after a bier block can lead to
seizures and/or cardiac arrest
Under general anesthesia, tourniquet pain manifests as
hypertension and tachycardia
Deflating the pneumatic tourniquet causes a
redistribution of circulating blood volume and exposes the body to the washout of metabolites that accumulated during limb ischemia
___________ is associated with the highest risk of bone implementation syndrome
Hip arthroplasty
In the awake patient under regional anesthesia, the first signs of BCIS are usually
dyspnea and AMS
Under GA, the first sign of BCIS is usually
a decreased EtCO2
First line treatment of BCIS is
100% FiO2
IV hydration
phenylephrine for hypotension
Risk factors for fat emboli syndrome include
pelvic fracture
femoral fracture
instrumentation of the femoral medullary canal
Releasing the tourniquet produces transient changes that include
increased EtCO2
decreased core body temperature
decreased blood pressure
decreased SvO2 (SaO2 is usually normal)
metabolic acidosis
Tourniquet pain is transmitted by
C fibers
What is the best way to treat intractable pain when using an orthopedic tourniquet in a patient with a neuraxial block?
convert to GA. this type of pain is unresponsive to analgesics
All of the following are associated with Samter’s triad EXCEPT:
a. allergic rhinitis
b. bronchospasm
c. nasal polyps
d. hypertension
d. Hypertension
Inhibition of Cox-1 enzyme does the following three things:
impairs platelet function
causes gastric irritation
reduces renal blood flow
Inhibition of the COX-2 enzyme produces
analgesia
anti-inflammation
antipyretic effects
Aspirin inhibits
COX-1 & COX-2 irreversibly
Aspirin-exacerbated respiratory disease (Samter’s triad) refers to the combination of
asthma
allergic rhinitis
nasal polyps
which can cause life threatening bronchospasm following administration
Toradol 30 mg IV is equivalent to morphine ________
10 mg IV
Acetaminophen is __________ an NSAID
NOT!
The most common cause of acute liver failure in the US is
acetaminophen
The max dose of acetaminophen is
4g/day
What NSAIDs have cox 2 selective inhibition?
Celecoxib
any drug that ends with -coxib
What are the key CV complications of NSAIDs?
increased risk of HTN, MI & HF (COX 2 inhibitors> Cox-1 inhibitors)
What are the key hematologic complications of NSAIDs?
platelet inhibition–> increased bleeding risk
Ketorolac can only be taken for
5 days
Aspirin toxicity can cause a
gap metabolic acidosis
List 6 drugs that inhibit the COX-2 pathway.
aspirin
ibuprofen
naproxen
ketorolac
diclofenac
indomethacin
Herbal medicines that increase bleeding tendencies include
garlic
ginger
ginko biloba
ginseng
Are herbal medicines contraindications to regional anesthesia?
no as long as the patient is not on other anticoagulant medications
Herbs that reduce MAC include
kava kava & valerian
Complications of ephedra-containing compounds (Ma Huang) include
SNS effects
catecholamine depletion
increased risk of serotonin syndrome when co-administered with MAOIs
St. John’s wort may
prolong duration of anesthetic agents & lead to serotonin syndrome with interaction with MAOIs and meperidine
