General ENT Flashcards
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
A child develops gray staining of the teeth with a prominent horizontal line across the upper and lower teeth after being prescribed an antibiotic. Which antibiotic was most likely prescribed?
Tetracyclin
Mechanism of action of aspirin
Irreversible acetylation of COX1. Effects last for the lifetime of the platelet which is 7-10days.
What drug can be given to reverse the antiplatelet effects of nonsteroidal anti-inflammatory drugs?
Desmopressin acetate (DDAVP)
In the event of significant bleeding following administration of heparin, what medication should be considered?
Protamine
Mechanism of action of warfarin
It is a vitamin K antagonist that inhibits the production of vitamin K dependent clotting factors
Mechanism of malignant hyperthermia?
An abnormal ryanodine receptor causes overwhelming amounts of calcium to be released from the sarcoplasmic reticulum of skeletal muscle thereby initiating prolonged and intense muscle contraction.
Initial treatment for malignant hyperthermia
Stop anesthetic, give dantrolene, increase O2, initiate cooling measures
Physical exam findings of cardiac tamponade
tachycardia, paradoxical pulse with respirations, hypotension, jugular vein distension, muffled cardiac sounds, decreased QRS amplitude on ECG
What complications may be encountered in a patient who has received massive intraoperative transfusions?
volume overload, hyperplasia or hypokalemia, hyperamonemia, acidosis, thrombocytopenia, coagulation factor depletion, coagulopathy, hypothermia, transfusion related acute lung injury, citrate toxicity (which causes hypocalcemia)
What common rule can be used to select the tidal volume and rate for a patient on assist control mechanical ventilation?
12-12 rule. 12ml/kg of lean body mass delivered 12 times a minute. Needs to be adjusted for lung disease (COPD)
What is the difference in the FEV1/FVC ratio in COPD vs restrictive lung disease
FEV1/FVC is decreased in COPD and increased or preserved in restrictive lung disease
Treatment of post obstructive pulmonary edema
Oxygen, supportive care, PEEP. Diuretic therapy can be instituted although benefit is unclear.
Ddx of the febrile patient after surgery
Wind: pneumonia, aspiration, atelectasis Water: UTI Walk: DVT, PE, Wound: surgical site infection Wonder drugs: drug reaction
What is eosinophilic granuloma?
Eosinophilic granuloma is the most common form of Langerhans cell histiocytosis and is characterized by the formation of solitary or multiple discrete nodules within bones.
Hand Schuller Christian disease
Multifocal Langerhans cell histiocytosis with bone “granulomas” associated with the triad of exophthalmos, lytic skull lesions, and diabetes insipidus
Letterer Siwe disease
Systemic Langerhans cell histiocytosis. Initial symptoms often include generalized skin eruption, anemia, and hepatosplenomegaly
Extranodal natural killer cell (NK)/T cell lymphoma is commonly associated with which virus?
EBV
Most common laryngeal manifestation of GPA?
Subglottic stenosis
Most common otologic manifestation of GPA?
Serous otitis media
What histopathologic findings are seen in GPA?
Necrotizing granulomas and arteritis involving small vessels
What lab test is used to diagnose GPA?
C-ANCA (will be + in more than 90% of cases)
What histopathologic finding is seen in sarcoidosis?
Noncaseating granulomas
Most common site of laryngeal involvement in sarcoidosis?
Supraglottis
What is the most common head and neck manifestation of sarcoidosis?
Cervical lymphadenopathy
Describe the natural history of untreated necrotizing sialometaplasia
Spontaneous resolution over weeks to months
Where is coccidioides immitis endemic?
Desert southwest including New Mexima, Nevada, California, Texas, Utah, and northern Mexico
Histoplasmosis most commonly occurs in which geographic location?
The Ohio, Missouri and Mississippi river valleys
Describe head and neck manifestations of disseminated histoplasmosis
Granulomatous lesions involving the lips, gingiva, tongue and larynx, pharynx manifesting with painful ulcers containing heaped edges
What are the common head and neck clinical manifestations of rhinosporidiosis?
Fleshy, friable strawberry like lesions most commonly involving the inferior turbinate, oropharynx, conjunctiva and perineum
What is the treatment for rhinosporidiosis?
Wide local excison or prolonged dapsone therapy
Presentation of primary syphilis
Painless ulcer (chancre) at the site of transmission demonstrating a rolled edge and punched out base present after 3-6 weeks at site of exposure
Presentation of secondary syphilis
Systemic spread of disease with manifestations including fever, myalgias, arthralgias, lymphadenopathy. Mucocutaneous rash often develops including the oral mucosa and the palms and soles. Condyloma lata and patchy alopecia may develop.
What are the three categories of tertiary syphillis?
Gummatous syphilis, cardiovascular syphilis, neuosyphilis
Argyll Robertson pupil
A pupil that does not react to light but does constrict during accommodation. Associated with syphilis.
Manifestation of otosyphilis
Associated with either congenital or tertiary acquired syphilis and manifests with high frequency SNHL, fluctuating tinnitus, vertigo
Jarisch Herxheimer reaction
After treatment of syphilis, dying spirochetes may trigger a cytokine cascade that manifests with myalgias, fever, headache and tachycardia
What tests are commonly used for syphilis screening?
VDRL and RPR
What confirmatory test should be ordered after a positive or equivocal screening test for syphilis?
FTA-ABS
What is the most common cause of subacute pediatric cervical lymphadenopathy?
Atypical mycobacterium
How is brucellosis transmitted?
From contaminated meat or dairy products or via direct contact through broken skin
Clinical manifestations of cat scratch disease
Primary lesion develops into an erythematous non-pruritic pustule 1 week after inoculation. Lymphadenitis of the axilla, neck and inguinal region commonly develops 2-4 weeks after exposure. Suppuration with acute tenderness and fever. Lymphadenopathy usually resolved over 2 weeks but may persist for up to 2 years.
What pathogen is responsible for development of rhinoscleroma?
Klebsiella rhinoscleromatis
What histologic findings are strongly suggestive of rhinoscleroma?
Russell bodies (immunoglobulin containing includions in plasma cells), pseudoepitheliomatous hyperplasia, Mikulicz cells (foamy histiocytes containing Klebsiella)
What is the treatment of rhinoscleroma?
Tetracycline or ciprofloxacin
What tests are helpful in diagnosing systemic lupus erythematosus?
ANA, anti-Sm, anti-DNA, anti ribonuclear protein (anti-RNP, anticardiolipin antibody
Which joints in the head and neck are most commonly affected by RA?
TMJ, Cricoarytenoid and ossicular joints
What does CREST stand for?
Calcinosis, Raynaud phenomenon, esophageal dysmotility, sclerodactyly, telangectasias
- CREST is a limited cutaneous form of systemic scleroderma
What are the histologic findings in a minor salivary gland lip biopsy performed in a patient for Sjogrens?
Focal lymphocytic infiltrate with atrophic acini
What is the most common head and neck manifestation of relapsing polychondritis?
Episodic auricular chondritis, presenting with erythema and pain of the pinna with sparing of the fatty lobule.
What histologic finding on temporal artery biopsy is suspicious for giant cell arteritis?
Inflammatory infiltrates in at least the adventitia and media with elastic lamina fragmentation.
Classic triad of GPA
Granulomas of the respiratory tract, progressive glomerulonephritis, necrotizing vasculitis of small to medial sized arteries and veins
What condition is characterized by uveitis, oral aphthous ulcers and genital ulcers?
Behcet disease
What are the two primary fascia networks of the neck?
Superficial cervical fascia and the deep cervical fascia
Describe the anatomy of the superficial cervical fascia?
It lies just deep to the dermis and superficial to the deep cervical fascia. It extends from the zygoma to the clavicle and envelops the platysma and mscles of facial expression.
Describe the anatomy of the deep cervical fascia?
It is composed of the superficial (investing), middle (visceral and muscular), and deep (prevertebral and alar) layer. The carotid sheath fascia is created by all three layers of the deep cervical fascia.
Describe the anatomy of the superficial (investing) layer of the deep cervical fascia?
It surrounds the neck and inserts superiorly at the nuchal ridge, mastoid, zygoma, and mandible and inferiorly at the clavicles, sternum, scapula, and acromion. It envelops the SCM, trapezius, muscles of mastication, submandibular gland and parotid gland. Inferiorly, its manubrial insertion splits to form the suprasternal space of Burns
Describe the anatomy of the middle (visceral and muscular) layer of the deep cervical fascia?
It extends superior to the cranial base and inferiorly to the mediastinum. It is subdivided into muscular and visceral layers. Muscular division surrounds the infrahyoid strap muscles. The visceral portion surrounds the pharyngeal constrictors, esophagus, trachea, and thyroids and creates the buccopharyngeal fascia. Both divisions contribute to the carotid sheath.
Describe the anatomy of the deep (prevertebral and alar) layer of the deep cervical fascia.
Both alar and prevertebral fascia extend superiorly to the cranial base the alar fascia fuses with the middle cervical fascia and extends into the upper mediastinum, and the prevertebral fascia extends to the level of the coccyx. The alar fascia and prevertebral fascia fuse at the vertebral transverse processes and after joining envelop the paraspoinous muscles.
Describe the boundaries of the buccal space
Created by the buccinator muscle medially; the superficial layer of the deep cervical fascia and the muscles of facial expression laterally and anteriorly; and the muscles of mastication, mandible and parotid gland posteriorly. Primarily contains adipose (buccal fat pad), minor salivary glands, accessory parotid tissue and facial/buccal arteries, veins and lymphatics.
Define the mechanism of spread of infection (or tumor) to and from the buccal space.
It permits spread between the mouth, parotid space and masticator space from deficient fascial compartmentalization along the superior, inferior and posterior limits.
Boundaries of the carotid space
It extends from the skull base to the mediastinum; anteriorly lies the sternocleidomastoid muscle, posteriorly the prevertebral space, and medially the visceral compartment.
Boundaries of the danger space
A potential space that rests between the alar fascia and the prevertebral fascia. Infections in this area can communicate with the thorax (mediastinum) to the level of the diaphragm
Boundaries of the masticator space
Created from the superficial layer of the deep cervical fascia surrounding the masseter laterally and the pterygoid muscles medially. Contains masseter muscle, pterygoid muscles, inferior tendon of the temporalis muscle, ramus, and posterior body of the mandible, internal maxillary artery and the inferior alveolar neurovascular bundle.
Boundaries of the parapharyngeal space
It is shaped as an inverted pyramid with the base at the cranial base and the apex at the hyoid bone. Anteriorly, it is bound by the pterygomandibular raphe, posteriorly by the prevertebral fascia, medially by the superior pharyngeal constrictor and laterally by the parotid, mandible and lateral pterygoid.
How is the parapharngeal space commonly dividied?
Prestyloid and poststyloid compartments are divided by tensor-vascular-styloid fascia connecting the tensor veli palatine and the styloid process
What structures are contained in the prestyloid space?
Fat, lymph nodes, minor salivary gland tissue, internal maxillary artery, and the inferior alveolar, ariculotemporal and lingual nerves
What structures are contained within the poststyloid space?
Carotid artery, internal jugual vein, cranial nerves 9-12 and the superior sympathetic chain
Boundaries of the parotid space
Created by the superficial layer of deep cervical fascia as it surrounds the mandible and parotid gland and containus the partid gland and parotid lymph nodes, the facial nerve, posterior facial vein and facial artery.
Describe the mechanism of infection or tumor spread from the parotid space to the parapharyngeal space
The superiomedial parotid space fascia is deficient, allowing for direct spread into the parapharyngeal space via the stylomandibular tunnel
Define the boundaries of the peritonsiallar space
Bound by the palatine tonsil medially and superior pharyngeal constrictor, palatoglossus and palatopharyngeus medially, superiorly, inferiorly, anteriorly and posteriorly. It contains loose areolar tissue and minor salivary glands.
Define the boundaries of the prevertebral space
It extends from the skull base tot he coccyx and is bordered anteriorly by the prevertebral fascia, posteriorly by the vertebral bodies and laterally by the transverse processes of vertebrae
Describe the sequential layers and spaces (superficial to deep) of the posterior pharyngeal wall
Mucosa, pharyngeal constrictor, buccopharyngeal fascia, retropharygneal space, alar fascia, danger space, prevertebral fascia, prevertebral space
Define the boundaries of the sublingual space
Contains the sublingual gland, Wharton duct, lingual and hypoglossal nerves and is bound superiorly by the mucosa of the floor of mouhth, laterally by the mandible, inferiorly by the mylohyoid, medially by the genioglossus, anteriorly by the mandible
What are the two divisions of the submandibular space?
Subdivided into the sublingual and submaxillary spaces which are separated by the mylohyoid. These two spaces communicate at the second molar.
Define the boundaries of the submaxillary space
Contains the submandibular gland and is bounded superiorly and medially by the mylohyoid muscle, inferiorly and posteriorly by the digastric muscle, and laterally and anteriorly by the superficial layer of the deep cervical fascia and mandible.
Define the boundaries of the infratemporal fossa
- Located inferior and medial to the zygomatic arch
- Anterior: posteriolateral portion of maxillary sinus
- Lateral: ramus of mandible
- Medial: lateral pterygoid plate
- Superior: greater wing of sphenoid
- Inferior: medial pterygoid muscle
- Posterior: articular tubercle of the temporal bone, glenoid fossa
Describe the branches of the three segments of the internal maxillary artery
- First: lateral portion - deep auricular artery, anterior tympanic artery, middle meningeal artery, inferior alveolar artery, accessory meningeal artery
- Second: middle portion - masseteric artery, pterygoid branches, anterior and posterior deep temporal arteries, buccal artery
- Third: medial portion - sphenopalatine artery (terminal branch), descending palatine artery, infraorbital artery, artery of the vidian canal, anterior, middle and posterior superior alveolar artery
Define the boundaries of the pterygopalatine fossa
- Located medial to the infratemporal fossa
- Anterior: posteriomedial portion of the maxillary sinus
- Lateral: pterygomaxillary fissure and infratemporal fossa
- Medial: perpendicular plate of the palatine bone
- Superior: body of the sphenoid bone
- Inferior: pterygopalatine canal
- Posterior: root of pterygoid plates
Name the foramina communicating with the pterygopalatine fossa
Anterior: inferior orbital fissure Lateral: pterygomaxillary fissure Medial: Sphenopalatine foramen Inferior: greater palatine canal Posterior: vidian canal, foramen rotundum
What important structure may be encountered if the vidian canal is followed posteriorly?
The second genu of the internal carotid artery
Define the boundaries of the temporal fossa?
It is located between the superficial layer of the temporalis fascia and the periosteum of the squamosal portion of the temporal bone and is subdivided into the superficial and deep layer by the temporalis muscle. It contains the internal maxillary artery and inferior alveolar nerve.
Describe the location and course of the hypoglossal and lingual nerves in the region of the submandibular gland?
Hypoglossal is located deep to the digastric muscle and mylohyoid and superficial to the hyoglossus muscle. Lingual is located cephalad to the hypoglossal nerve.
What landmarks can be used for identification of the accessory nerve during level 2 neck dissection?
Transverse process of C1, anterolateral to the internal jugular vein, two fingerbreadths below the mastoid tip, or just as it runs posterior to the SCM 1-2cm above Erb point.