3. Management of Maxillofacial Infections Flashcards
Describe the path of third molar infection to the mediastinum
-PA abscess erodes through thinnest cortical plate (lingual) into submandibular space
-Infection travels through buccopharyngeal gap between the middle and superior pharyngeal constrictors to the lateral pharyngeal space
-A direct connection to the lateral pharyngeal space is around the posterior belly of the digastric
-There is no barrier between the lateral pharyngeal space and retropharyngeal space
-Retropharyngeal space fuses with the alar fascia between C6-T4
-Infection enters danger space at fusion of alar and prevertebral fascia
-Danger space continuous with posterior mediastinum
Principles of management of odontogenic infection
- Determine severity (anatomic location, rate of progression, airway compromise).
- Evaluate host factors: immunocompetence and systemic reserve.
- Decide on setting (inpatient criteria = fever, dehydration, need for GA, deep space infection, control of systemic disease).
- Treat surgically
- Support medically
- Choose and administer appropriate antibiotic
- Evaluate patient frequently
What are the primary fascial spaces?
Primary fascial spaces are those that are directly adjacent to the origin of odontogenic infections. Infection spread by direct invasion from source.
1. Buccal
2. Submandibular
3. Canine
4. Submental
5. Vestibular
6. Sublingual
What are the secondary fascial spaces?
Secondary fascial spaces are those that become involved via spread of infection from primary fascial spaces.
1. Pterygomandibular
2. Infratemporal
3. Masseteric
4. Masticator
5. Lateral pharyngeal
6. Retropharyngeal
7. Prevertebral
What are some disease processes that render a patient immunocompromised?
HIV, DM, hepatitis, alcoholism, malnutrition, malignancy, chemotherapy, steroids, immunosuppressants
Study the borders of deep fascial spaces of the head and neck
P. 46
What would you see in a CBC for an odontogenic infection patient?
leukocytosis
left shift
leukopenia can also be seen in serious infection
thrombocytosis can be seen in setting of infection (acute phase reactant)
left shift refers to presence of immature white blood cells released into the bloodstream denoting an acute infection
What other labs would you order (other than CBC)
BMP: BUN/creatinine ratio can be used to assess volume status of the patient.
Renal baseline function important to know as certain antibiotics are nephrotoxic, which may have implications on dosing. Creatinine levels also necessary prior to CT with contrast due to risk of contrast-associated nephropathy.
Hyperglycemia/hypoglycemia may be present. Blood sugar below 200mg/dL is imperative for infection control.
Electrolyte disturbances may also be present.
Systemic Inflammatory Response Syndrome (SIRS) criteria
SIRS is defined as two or more of the following:
1. Fever >38C or <36C
2. HR >90
3. RR >20 or PaCO2<32
4. Abnormal WBC count (>12,000/mm3 or <4000/mm3 or >10% bands)
What is sepsis?
A life-threatening organ dysfunction caused by dysregulated host response to infection
What are 5 classifications of orbital infections?
- Inflammatory edema (pre-septal cellulitis)
- Orbital cellulitis
- Subperiosteal abscess
- Orbital abscess
- Cavernous sinus thrombosis
What is the orbital septum?
Membranous sheet that extends from the periosteum of the infraorbital region to the tarsal plate and forms the anterior boundary of the orbital compartment
What is the most common route of infection into the orbit?
Extension from the ethmoid sinuses.
Lamina papyracea separates ethmoid sinuses from the orbit. Nerves and vasculature within natural fenestrations are named Zuckerkandl’s dehiscences.
Route of orbital infection into cavernous sinus
Through the superior and inferior ophthalmic veins.
What clinical features distinguish postseptal/orbital cellulitis/abscess from pre-septal cellulitis?
Ophthalmoplegia, decreased visual acuity, proptosis, eye pain (ophthalmalgia), changes in visual acuity, superior orbital fissure syndrome, orbital apex syndrome.
