Infection Flashcards

Question

What is the medical management of an odontogenic infection?

Answer 1

-IV fluids to address dehydration -Initiate emperic antibiotic therapy -Change once cultures and sensitivity becomes available (can obtain adequate cultures from cellulitis) -Analgesics -Determine spaces involved -Admit for serious infection (hospital admission criteria: Temp >101, dehydration, signs of airway embarrassment, infection involving secondary spaces, need to control systemic disease, need for GA)

Answer 2

-Suction bedside -NPO -Monitor I's & Os -Q4 vital signs -HOB elevated 30 degrees

Answer 3

-Discuss securing a definitive airway with anesthesia before the OR (awake fiberoptic or awake trach if needed) -Consider needle decompression prior to intubation to prevent rupture of abscess with intubation -Be prepared for emergency tracheostomy in the "can't ventilate can't intubate) situation -Mark out emergency cricothyrotomy prior to intubation attempt -Attempt aspiration for sterile sample for culture and sensitivity -Make an incision in healthy skin versus height of fluctuance to prevent scar contracture -Place incision in natural skin fold to allow for dependent drainage -Bluntly dissect involved spaces to establish drainage -Copious irrigation -Place drains (possibly through and through -Extract offending teeth -Re-assess patient -Consider ID consult

Answer 4

-Different anatomic sites and clinical manifestations -Evaluate visual acuity, pupillary reflexes, extraocular movement and opthalmoscopy -Rare sequelae of sinusitis, odontogenic infections or orbital trauma

Answer 5

-Group 1: Inflammatory edema (preseptal cellulitis) -Group 2: Orbital Cellulitis -Group 3: Subperiosteal abscess -Group 4: Orbital abscess -Group 5: Cavernous sinus thrombosis

Answer 6

-A membranous sheet that extends from the periosteum of the infraorbital region to the tarsal plate and forms the anterior boundary of the orbital compartment

Answer 7

-Extension from the ethmoid sinuses

Answer 8

-Superior and inferior ophthalmic veins drain blood directly into the cavernous sinus -Inferior orbital veins are valveless and infections can pass readily from orbit to intracranial structures

Answer 9

-Usual review of medical history, systems and duration/onset. Emphasis on symptoms of decreased vision and decreased color perception -Lab tests: CBC, BMP, blood cultures -Visual acuity (Snellen chart) -EOM movement -Pupillary examinatino (afferent pupillary reflexes) -Ocular pressures -Fundoscopic exam (access optic nerve involvement, papilledema: optic nerve swelling) -Consider opthalmology consultation -Posterior orbital involvement around the superior orbital fissure and optic foramen may result in orbital apex syndrome

Answer 10

-CT orbits and /or sinuses with contrast: 3 mm cuts to distinguish preseptal and orbital cellulitis -Preseptal cellulitis: Diffuse soft tissue edema seen anterior to septum on CT -Postseptal cellulitis: Intraconal fat stranding and edema of the extra-ocular muscles are seen -Postseptal abscess: Collection of purulent material (ring enhancing lesion) between bony walls of orbit and periorbita. Displacement of globe away from abscess

Answer 11

-Infection confined to the lids and periocular soft tissue anterior to the orbital septum -More common in children than adults -Sources: Paranasal sinusitis, URI, direct inoculation -Bacteria: Staph aureus, strep pneumoniae, haemophilus influenze, other strep, anaerobes -Clinical: Ocular pain, eyelid swelling, erythema, chemosis, can occur

Answer 12

-Antibiotics: Community-acquired MRSA (Clinda or TMP/SMX) -Serial ocular exams looking for deteriorating or improving symptoms -HOB elevated -If abscess defined, drainage via transcutaneous, transconjunctival or transnasal endoscopic approach through ethmoid sinus

Answer 13

-True involvement of the orbital contents -More common in young children -Can have + blood cultures (in kids, rarely adults) -Most common cause is rhinosinusitis. Other causes opthalmic surgery, trauma, dacryocystitis, odontogenic infection -Presents with Opthalmoplegia, decreased visual acuity, proptosis, eye pain, changes in visual acuity, superior orbital fissure/orbital apex syndrome -Abscess usually located medially or supero-medially (causes fixed looking down and out) -Most common bacteria Staph aureus, strep, muco/aspergillus, can be life threatening

Answer 14

-Orbital abscess must be drained (uncomplicated cellulitis may attempt conservative tx 24-48h only) -Broad spectrum antibiotics (Vanc, unasyn, metronidazole, ceftriaxone, piperacillin/tazobactam, levo) -If intracranial extension include anaerobic coverage and NSGY consult -Contrast CT or MRV (venogram) -Approach: Transconjnctival w/ or w/o transcaruncular or lateral canthotomy extension. Endoscopic sinus surgery if pt with rhinosinusitis -May consider steroid 24h after antibiotic therapy has begun (prevent ocular complications due to increased intraorbital pressure) -Emergency lateral canthotomy and cantholysis may be required if signs of ocular involvement

Answer 15

-A vascular thrombosis in the cavernous sinus with inflammation of its anatomic structures

Answer 16

-Contiguous spread of infection from the sinuses (very uncommon from dental abscess) -Staph aureus most common pathogen

Answer 17

-Bilateral venous drainage for middle cranial fossa -Anterior border is superior orbital fissure (tributaries of opthalmic vein) -Posterior border is trigeminal ganglion -Sup/inf opthalmic veins, central retinal vein, middle meningeal vein drain into cavernous sinus -Drains into petrosal sinuses -Emissary veins drain from sinus into pterygoid plexus to the retromandibular vein Nerves in sinus: CN III, IV, V1, V2, VI

Answer 18

Aseptic cases: After surgery or trauma Infectious causes: Sinusitis, otitis, facial fruncles, erysipelas (cellulitis of skin caused by b-hemolytic strep and grou B strep) Symptoms: Fever, headache, diplopia Clinical signs: Photophobia, proptosis, sepsis, lid edema, chemosis, dilated pupils, ophthalmoplegia, congested retinal vein

Answer 19

-Lateral gaze palsy (CN 6) -Congested retinal vein on opposite side may be even earlier

Answer 20

-Nausea/vomiting -Altered mental status -Generalized sepsis -May result in meningitis, encephalitis, blindness, brain abscess, empyemas, coma and death

Answer 21

-Triangular region from corners of mouth, medial cheek and bridge of nose -Pathway is via retrograde flow through veins that are valveless. -Facial to angular to ophthalmic to cavernous sinus -Emissary veins to pterygoid plexus -IJV to inferior petrosal sinus (Lemierre's syndrome)

Answer 22

MRV (Magnetic resonance venography) -Imaging modality of choice to evaluate venous anatomy and detect thrombosis CT with and w/o contrast -Expansion of cavernous sinus, convexity of lateral wall

Answer 23

Surgery -Directed at primary source of infection and obtaining culture Antibiotics (combo of 3) -3rd or 4th gen cephalosporin that crosses BBB: Ceftazidime) -Metronidazole -Vancomycin -6-8 week therapy (can change once C&S returns) Steroids (controversial) -May decrease orbital inflammation and cranial nerve edema Anticoagulants (controversial) -Cessation of progression of thrombosis, can decrease morbidity -Risk: Intracranial and systemic hemorrhage

Answer 24

-Opportunistic fungal infection that occurs in immunocompromised patients -Two forms are rhinocerebral and rhinomaxillary

Answer 25

-Black necrotic eschar in oral cavity/palate (thrombosis, vascular invasion, ischemia/infarctions)

Answer 26

-Ketone reductase -High glucose, acidic conditions (diabetic ketoacidosis)

Answer 27

-Seen most frequently on palatal ulcers -Necrotic, well defined borders -Diagnosis by biopsy: Broad non-septate hyphae at right angles

Answer 28

-Early ID and treatment -Eliminate predisposing factors (hyperglycemia, metabolic acidosis, imunosuppressive drugs, neutropenia) -Surgical and antifungal therapy -Systemic IV (High dose amphotericin B). Monitor nitrogen, creat, creat clearance (binds fungal membrane, increases ion permeability -Posaconazole/isavuconazole can be used as salvage thearpy -Aggressive surgical debridement

Answer 29

-Aggressive bacterial infection leading to necrosis of the superficial fascial planes with concurrent systemic toxicity -High mortality due to sepsis -More common in immunocompromised patients/diabetic

Answer 30

Type I: Mixed aerobic/anaerobic (most commonly seen) Type II: Strep pyogens (group A beta hemolytic strep) (seen more in children) Type III: Staph aureus (MRSA) Type IV: Clostridial, gas producing Type V: Klebsiella (may be resistant to antibiotics)

Answer 31

-Erythematous skin w/o demarcation that is tense, smooth, shiny, and painful -Signs of sepsis: Tachy, pyrexia, apathy, weakness, hypotension -Progression leads to vesicle and blister formation, dusky purple skin follows -Crepitus may be present due to gas production -Drainage described as dishwater due to foul smell, low viscosity and gray color

Answer 32

-Soft tissue emphysema and edema, possible gas bubbles

Answer 33

-CBC: Extreme leukocytosis, anemia (bacterial hemolysis and bone marrow suppression) -CMP: Hypocalcemia (sequestration of calcium), elevated blood glucose, elevated blood urea nitrogen, elevated creatinine -Lactate levels will be increased

Answer 34

-Secure definitive airway -Early recognition leading to surgical intervention via fasciotomy and necrotic tissue debridement. Muscle layers can be preserved but all necrotic tissue and overlyign skin must be removed -Biopsies of involved fascia to identify toxin-producing invasive streptococcal infection -Gram-positive cocci invading fascia without leukocytic infiltrate indicated streptococcal toxin production -Frozen sections show dense polymorphonuclear infiltrates in the dermal layers of skin; these may guide removal of devitalized tissue -Biopsies should be taken of adjacent normal looking tissue -Broad spectrum antibiotics (carbapenem plus vancomycin to cover all 5 types of infections), de-escalation according to culture and sensitivity results -Wounds should be washed (consider peroxide, consider antimicrobial soaked packing-povidone iodine) -Hyperbaric oxygen consideration -Fluid electrolyte and blood replacement for volume repletion and hemolysis -Secondary reconstruction may require locoregional flaps and skin grafts

Answer 35

-A life-threatening infection involving the mediastinum -Can spread from an odontogenic source via the danger space (also called Space 4) that is found between the alar and prevertebral fascia (This space extends from the base of the skull through the posterior mediastinum to the level of the diaphragm. Loose areolar tissue allows for rapid spread of infection. Usually enters through the fusion of alar and prevertebral fascia between C6 and T4)

Answer 36

-Chest pain -Dyspnea -High fever -Tachypnea -Hypotension (decreased venous return)

Answer 37

-Mediastinal widening and pulmonary congestion/effusions can be appreciated on chest radiographs -CT may show location of collection, tissue emphysema, pericardial effusions, and decreased airway patency

Answer 38

-Establish a definitive airway -Aggressive surgical source control including drainage of spaces (repeat drainage and debridement often required) -Cardiothoracic surgery consultation for open mediastinal drainage -HBO therapy may be indicated

Answer 39

-It is an inflammation of the medullary portion of bone. It frequently involves the cortical bone and periosteum, however. -Bone marrow offers a path of lower resistance that allows for spread along medullary bone -Most often seen in the mandible as the thin cortical bone of the maxillae does not easily confine the infectious process. Mandible also not as well vascularized

Answer 40

-Odontogenic mixed flora (primarily alpha-hemolytic streptococci vs staphlococcus aureus)

Answer 41

-Acute or chronic (1 month or greater) -Suppurative or non-suppurative (pus forming)

Answer 42

-Pain, trismus, paraesthesia/anesthesia, anorexia, swelling, loose teeth, adenopathy, malaise. -Chronic disease may form fistula or sinus tract

Answer 43

-Scouting film like an orthopantogram may show odontogenic infection with or without sequestra -CT scan can show extent of lytic bone, keeping in mind 30% demineralization is required to appreciate change -Radionuclide imaging: Allows for earlier identification of osteomyelitic activity (3 days). Technetium-99 although non-specific, will aid in identifying areas of higher blood flow and osteoblastic activity. Gallium 67 aides in ruling out osteomyelitis from malignancy and trauma. Identifies inflammatory changes as it binds to granulocytes -WBC tagging can be useful in detecting early infection when lytic processes aren't seen on imaging -PET CT with fluoride isotope is sensitive to areas of bone turnover with much greater resolution

Answer 44

-Patient should be treated with corticotomies (bur fenestration) or removal of the buccal bone (decortication) for decompression, plus removal of infected teeth or repair of mobile fracture segment -Infected bone marrow should be debrided until it bleeds, Useful to send multiple cultures and histopathological samples along the length of involved bone to see extent of infection/flora -Cultures and bone biopsy: Get micro for cultures/sensitivities, rule out neoplasia, ID fungi or actinomycosis in samples -Infectious disease service should be consulted due to need for long term IV antibiotics/PICC line -Hyperbaric oxygen should be considered to aid in revascularization and for antimicrobial utility

Answer 45

-MOA: Beta lactam antibiotics inhibit penicillin-binding proteins, which disrupt cell wall synthesis -Bactericidal

Answer 46

-Penicillins -Cephalosporins -Cephamycins -Carbapenems -Monobactams (aztreonam)

Answer 47

-Bind to the catalytic site of beta-lactamases to prevent hydrolysis of the beta-lactam -Ex: Tazo-bactam, sulbactam, clavulanate -Used with a PCN to cover bacteria that confer their resistance through liberation of beta lactamases

Answer 48

-Unasyn (Ampicillin and sulbactam) -Zosyn (Piperacillin and tazobactaum) -Augmentin (Amoxicillin and clavulanate)

Answer 49

-MOA: Binds to 50S ribosomal subunit and inhibits bacterial protein synthesis -Bacteriostatic -Ex: Erythromycin, clarithromycin, azithromycin -Side effects: Prolong QT, nausea, diarrhea

Answer 50

-Binds to 50S ribosomal subunit and inhibits bacterial protein synthesis -Bacteriostatic or bactericidal depending on concentration, infection site and organism -Side effects: Pseudomembranous colitis

Answer 51

-Treatment with antibiotic alters normal flora of large intestine and leads to overgrowth of C. difficile -C. difficile produces toxins A and B that lead to cytoskeleton destruction and leaks. Proinflammatory cytokines that further intestinal mucosal damage -Diagnosis: C. difficile toxin via stool sample -Tx: Discontinue antibiotic. Stop opiates or anti-diarrheal medication. Administer fluids and correct electrolytes. -Antibiotic treatment is: 10-14 days of metronidazole or oral vancomycin. Fidaxomicin is now also available

Answer 52

-Usually occurs in elderly, extended hospital stay, exposure to IV antibiotics -Rapid WBC spike, abdominal pain/distension, fever -Goal is to decompress bowel within 24h or total colectomy

Answer 53

-MOA: Inhibits DNA gyrase/topoisomerase which are involved in DNA replication -Bactericidal -Ex: Ofloxacin, ciprofloxacin, levofloxacin, moxifloxacin -Side effects: Chondrotoxicity (avoid in children <18 years old), tendinitis/tendon rupture, prolonged QT

Answer 54

-Ampicillin-sulbactam -1.5-3 g IV q6-8h

Answer 55

-Piperacillin-tazobactam -1.5-3 g IV q6-8h

Answer 56

-Cephalexin -500 mg PO q6h

Answer 57

-Azithromycin -250 mg PO BID for first day, 250 mg PO Q daily x4 days

Answer 58

-Moxifloxacin: 400 mg PO q daily -Levofloxacin (levaquin): 500 mg PO q daily

Answer 59

-Prosthetic heart valve or heart valve repaired with prosthetic material -History of endocarditis -Heart transplant with abnormal heart valve function -Cyanotic congenital heart disease that has not been fully repaired (including surgical shunts or conduits) -Repaired congenital heart disease with residual defects

Answer 60

-Amoxicillin 2g (Pediatric 50 mg/kg) If allergic to PCNs -Cephalexin 2g (Pediatric 50 mg/kg) or -Azithromycin 500 mg (Pediatric: 15 mg/kg)