7. Oral and Maxillofacial Infections Flashcards
What is an odontogenic infection
One in which the source of infection is from the teeth Access through necrotic pulp or deep pocket Polymicrobial in nature (avg of 5 bacteria)
What type of bacteria typically cause odontogenic infections?
Aerobic gram + cocci Anaerobic gram + cocci Anaerobic gram - rods
Progression of odontogenic infection
Initial inoculation Aerobic bacteria (more virulent) start infection Cellulitis (diffuse) type of infection Local reduction-oxidation potential is lowered Anaerobic bacteria begin to grow Abscess type of infection Anaerobic bacteria become exclusive
Describe initial inoculation phase
duration: 0-3 days small and diffuse, not localized mild, minimal/no loss of function edema aerobic bacteria tx: remove source of infection, systemic AB
Describe cellulitis phase
acute, 3-7 days large, severe and generalized diffuse borders hard, indurated & tender serosanguinous (serum and blood) aerobic and anaerobic bacteria thick & red skin severe loss of function tx: treat and remove source; incision & drainage (I&D); systemic AB
Describe abscess phase
chronic, >5 days moderate & localized small, well circumscribed fluctuant, tender pus moderate-severe anaerobic bact shiny & peripherally red moderate loss of function tx: remove infection source, I&D, with or w/o systemic AB
4 steps of diagnostic workup
- Pt assessment: history & physical exam 2. Imaging 3. Lab Studies 4. Aspiration
What do we look for in the physical exam of the head and neck?
Swelling, abscess, vital signs, fistula, trismus, cause of infection, airway evalutation
What do we look for in radiographs?
Bone changes (not seen in acute) Collection of pus demarcated by radioopaque halo Extent of spread of infection Airway constriction
What do we check in lab studies?
CBC WBC with differential (high in infection)
How is aspiration done?
Use 18 gauge needle Expel air Recap Needle Send specimen for gram stain and culture
What factors influence the spread of infection?
Host factors: -local factors (anatomical) -systemic factors (status of host defenses) Bacterial factors: -bacterial virulence -bacterial drug resistance
How do compromised host defenses affect infection?
More frequent infections Infections progress rapidly
Principles of therapy of odontogenic infection
- Determine severity of infection from the Dx workup 2. Evaluate state of patient’s host defense mechanisms 3. Treat infection surgically 4. Support patient medically 5. Choose & prescribe appropriate Abx 6. Administer Abx properly 7. Evaluate patient frequently
What would be indications for hospital administration?
temp >101F dehydration toxic appearance difficulty breathing or swallowing rapidly spreading infection fascial invovlement spread of infection to secondary spaces trismus threat to airway or vital structures compromised host defenses need for general anesthesia
How do we treat infections?
Surgically: 1. Remove cause of infection 2. Provide drainage of pus 3. Do not wait for unequivocal accumulation of pus 4. Remove foreign body 5. If potentially life-threatening, intubate/secure airway early on
Principles of I & D
-aspirate before incision -place incision in healthy skin/musosa -place incision in aesthetically acceptable area (near natural crease) -use blunt dissection to avoid damage to vessels -advance closed hemostat, spread beaks, and remove completely before reinserting -secure drains with sutures & irrigate -monitor drain output
What instructions/medical support should you give the pt?
-encourage perioral fluid intake -support nutrition by high calorie nutrition supplement -prescribe analgesics for pain -rest -careful instructions
What determines need for AB?
- seriousness of infection 2. whether adequate surgical tx can be achieved 3. state of pt’s host defenses
Indications for AB use
Rapid progressive swelling Diffuse swelling Compromised host defenses irrespective of type of infection Involvement of fascial spaces Osteomyelitis
What is AB of choice?
Penicillin If allergic, use clindamycin or clarithromycin
Factors to consider when choosing AB
Use narrow-spectrum, bacteriocidal AB Keep in mind cost for patient (penicillin is cheap) Low incidence of toxicity and side-effects
What is a primary space?
One that is in direct contact with alveolar structure (these are the first to get infected) E.g. canine, buccal, infratemporal, submental, submandibular
What is a secondary space?
Spaces that can’t be involved until infection of a primary space E.g. masseteric, pterygomandibular, prevertebral
What is the most common source of infection in the infratemporal space?
3rd molars
What is an uncommon, but potentially lethal extension of odontogenic infection?
Cavernous Sinus Thrombosis
What are symptoms of cavernous sinus thrombosis?
Headache, fever, malaise (precede ocular findings) Proptosis, orbital swelling, and pain
Tx of Cavernous Sinus Thrombosis
AB, corticosteroids, and heparin
Which primary spaces are drained extra-orally?
Submandibular and submental
