General ENT Flashcards
(268 cards)
Sensitivity
The ability of a test to identify correctly those patients with the disease
Specificity
The ability of a test to identify correctly those patients without the disease
Is high sensitivity or specificity most important for a screening test?
Sensitivity
Type I error
The chance of testing positive among those without the condition; false positive rate = 1-specificity
Type II error
The chance of testing negative among those with the condition; false negative rate = 1-sensitivity
Positive predictive value
The chance of having the condition among those that test positive
Negative predictive value
The chance of not having the condition among those that test negative
A cervical spine X ray revealing a greater than 5mm widening of the predentate space (between the anterior surface of the dens and the posterior surface of the C1 tubercle) is worrisome for what traumatic injury?
Atlantoaxial dissociation
Traditional xray view for facial bones and neck (largely now replaced by CT)
- Lateral view (5 degrees of true lateral) - frontal, maxillary and sphenoid sinus
- Caldwell view (15 degrees off caudal angulation) - frontal sinuses, posterior ethmoid air cells, orbital floor
- Waters view (neck in 33 degree extension) - maxillary sinuses, anterior ethmoid air cells, orbital floor
- Submentovertex view (AP projection, head in 90 degrees of extension) - sphenoid sinuses, anterior and posterior wall of frontal sinuses
- AP and lateral views - soft tissues of the neck
Schuller view
lateral xray view of the mastoid with 30 degrees of cephalocaudad angulation
Stenvers view
Xray view of the petrous apex with patient facing the film, head slightly flexed and turned 45 degrees opposite the film
Towne view
Xray comparison of both mastoid bone and petrous pyramids via AP view with 30 degree tilt
T1 weighted appearance of water and fat on MRI
Low intensity and high intensity respectively
What does the presence of an echogenic (fatty) hilum typically indicate during US of the neck?
Benign disease. Normal lymph nodes have a fatty hilum whereas an absent hilum is often seen with metastic lymph nodes
Differences between first and second generation antihistamines
Compared with first generation, second generation meds generally have a longer duration of action, less CNS penetration and are less sedating.
Contraindications to glucocorticoid steroid use
Psychosis, severe diabetes, peptic ulcer disease, congestive heart failure, severe hypertension, systemic TB, osteoporosis
What severe neurologic side effect is associated with intramuscular administration of prochlorperazine (used for nausea and vomiting and schizophrenia)?
Extrapyramidal side effects including focal dystonia
Maximum dose of lidocaine
4-5mg/kg without epi 7mg/kg with epi, maximum total dose of 300mg
What medication can be given to reverse the effects of local injectable epinephrine?
Local infusion of 1.5-5mg of phentolamine
What is the mechanism of action for Beta lactam antibiotics
Binds to DD transpeptidase and inhibits the formation of peptidoglycan cross links in the bacterial cell wall.
What is the mechanism of action of aminoglycosides?
They irreversible bind to the 30S ribosome and freeze the 30S initiation complex. Additionally, they cause misreading of the mRNA code (bactericidal)
A mutation in which a gene may lead to increased aminoglycoside toxicity even at low doses?
Mitochondrial 12S ribosomal RNA gene
Mechanism of action of macrolides
They inhibit translocation of the peptidyl tRNA from the A to the P site on the ribosome by binding to the 50S ribosomal RNA (bacteriostatic)
Most common antibiotics that have been implicated in the development of C. diff
Second and third generation cephalosporins, ampicillin/amoxicillin, and clindamycin