518 Emergency Medicine
appearance of the scar is not reflective of the long-term outcome. (c)Facial
sutures should be removed in 3 to 5 days. Leaving sutures in for 7 to 10 days
lead to a poorer outcome.
471.The answer is d.(Roberts and Hedges, pp 562-563.)Themental
nerveis a continuation of the inferior alveolar nerve. It emerges from the
mental foramen below the second premolar and innervates the mucosa
and skin of the lower lip.A mental nerve block is the most appropriate
way to anesthetize this patient given his lip swelling.
(c)Local injection with lidocaine will cause further swelling and distort
the anatomy further. A mental block will provide anesthesia without distorting
the lip anatomy. (e)The block should be performed with a 25- or 27-gauge
needle. An 18-gauge needle is too large for the procedure. The mental foramen
should be palpated with a gloved finger. It is located 1-cm inferior and
anterior to the second premolar. Lidocaine should be injected around the
foramen.(a)Injecting directly into the foramen should be avoided because
it can cause neurovascular damage. (b)This patient will require bilateral
mental blocks because his laceration crosses the midline.
472.The answer is a.(Tintinalli, pp 297-298.)Tissue adhesivesclose
wounds by forming an adhesive layer that brings the edges of the laceration
together. They cannot be used on mucosal membranes and areas with thick
hair. For optimal results, it should be applied in three to four layers in a dry,
bloodless field.
(b)Tissue adhesives rate of infection and dehiscence are comparable to
sutures when used appropriately. (c)They are best suited for small (< 5 cm),
clean, straight wounds in low tensile areas. (d)It is applied as a layer on the
intact epithelium while holding close approximation of the wound edges. It
cannot be used inside the wound because it leads to an intense inflammatory
reaction. (e)After application the wound must be left open to air. Applying
topical antibiotics and bandages would cause prolonged exposure to moisture
leading to weakening of the adhesive layer. Patients should be instructed not to
pick at the edges of the layer and allow it to slough off naturally in 5 to 10 days.
473.The answer is c.(Roberts and Hedges, pp 681-682, Tintinalli, pp 300-301.)
Ptosisresults from a laceration through the levator palpebrae muscle or
its tendinous attachment to the tarsal plate.Repair requires reattachment
of the muscle. If the emergency physician is unable to recognize and repair
the muscular defect, an ophthalmology consult is warranted.