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Dental surgery. The most common forms of dental surgery are brief and relatively noninvasive
procedures often performed on an outpatient basis. A patient's anxiety is frequently
disproportionate to the safety of the procedure; such a patient may benefit from
behavioral or pharmacologic (anxiolytic) therapy. Mild pain associated with most forms of
uncomplicated dental care such as simple tooth extractions, endodontic therapy, or scaling
of the periodontal area or of Pa previously asymptomatic tooth is well managed by oral
administration of an NSAID such as aspirin or ibuprofen. Preoperative administration of
ibuprofen appears to delay the onset of postoperative pain and lessen its severity
(Jackson, Moore, and Hargreaves, 1989). For patients unable to tolerate aspirin or
ibuprofen, acetaminophen can provide an acceptable analgesic effect.
Dental procedures such as surgical removal of bony impactions
and osseous periodontal surgery are more traumatic and typically produce intense and
prolonged postoperative pain. The onset of such pain can be delayed by preoperative
treatment with ibuprofen and/or application of a long-acting local anesthetic such as
bupivacaine during the procedure.
Rarely, an intravascular or intraneural injection of local
anesthetic in this context leads to bruising, bleeding, or systemic symptoms such as
fainting, allergic reaction, or persistent pain due to direct nerve injury. When
postoperative pain does emerge, it often requires the addition of an opioid to the
nonsteroidal regimen. Codeine is frequently prescribed at a dosage of 30-60 mg every 4-6
hours. Increased analgesia—but also an increased number of opioid side effects such
as nausea, constipation, sedation, and respiratory depression follow dosage increases
above this level. Alternative opioids include propoxyphene or oxycodone administered in
doses that are equianalgesic to 30-60 mg of codeine.
Some operations on the oral cavity preclude the patient's
taking oral medications postoperatively (e.g., wiring the mouth closed after an operation
on a mandibular fracture). Alternative therapy should be based on the severity of the
surgical procedure and expected pain associated with it, as well as the surroundings in
which it will be managed. Formulations of NSAIDs such as rectal suppositories
(indomethacin) or intramuscular injection (ketorolac) are now commonly available. Opioids
may be administered by a variety of routes (intravenous, intramuscular, subcutaneous
injection, transdermal, rectal) and schedules, including a patient controlled schedule.
Cost-efficacy analyses of parenteral opioid administration for oral surgery are not
sufficient to permit any clear recommendations. Pain that does not respond to these
measures should prompt a search for infection, osteitis, peripheral nerve injury, or the
emergence of psychological and behavioral changes consistent with the development of
chronic pain syndrome.
Radical head and neck surgery.
These operative procedures commonly interfere with oral
intake for prolonged periods postoperatively and may be combined with a feeding
gastrostomy or jejunostomy. Airway patency is always a consideration in these patients,
and a tracheostomy frequently is an integral part of the operation. The use of flap
coverage or skin grafts further increases the number of potentially painful sites.
Prolonged preoperative pain, radiotherapy, and chemotherapy are important preoperative
modifiers of pain therapy. Thus, the very nature of the operative procedure may dictate
alternate routes for pain therapy in patients who have undergone major head and neck
ablative procedures that may interfere with a patient's ability to describe pain and his
or her response to analgesic Intervention.
Intraoperative positioning of the head and neck are critical.
Protective padding and avoidance of extreme flexion, extension, and rotation may help
obviate or minimize muscle spasm-induced pain after surgery. Foam cushion supports under
the occiput can minimize decubitus, pressure-induced headache, palsies, and causalgia.
Intraoperative traction on muscles and nerves should be started carefully and monitored
during the operation to prevent reflex myalgias and causalgias. Painful swallowing after
head and neck; ear, nose, and throat; and endocrine surgical procedures may require elixir
(i.e., liquid) forms of pain medicine, a modified diet, including liquid or soft foods,
and occasional use of topical anesthetics such as viscous lidocaine.
Postoperative pain is often short term and of moderate
intensity. Within 1-3 days, parenteral and oral opioids can be discontinued or replaced
with non-opioid analgesics (which may have to be delivered via gastrostomy or
jejunostomy). The use of most NSAIDs may be contraindicated for such procedures as
thyroidectomy and parathyroidectomy where postoperative hemorrhage and risk of airway
obstruction are significant. In such cases. acetaminophen or"platelet-sparing"
NSAIDs may be ordered.
Neurosurgery.
Patients undergoing an operation on the central nervous
system frequently show abnormal neurologic signs and symptoms that must be closely
followed in the postoperative period. In addition, these patients may receive drugs
designed to reduce cerebral edema or prevent seizures. A major dilemma in this clinical
setting is the need to carefully monitor critical neurologic signs such as pupillary
reflexes and the level of consciousness that may be affected by conventional opioid
analgesics used for the relief of postoperative pain.
Ideally, postoperative pain control should not interfere with
the ability to assess a patient's neurologic status, particularly the level of
consciousness, or with assessment of motor and sensory function following spinal cord
surgery. Therefore, the administration of opioids, benzodiazepines, and anxiolytics, in
particular, is relatively contraindicated. However, the clinician must balance the need
for analgesia with the requirement for appropriate neurologic monitoring.
The uncomplicated postcraniotomy patient typically has mild
to moderate pain and is readily managed by a short period of parenteral medications
followed by oral analgesics. Laminectomy and other spinal procedures usually are more
painful than craniotomies. Ketorolac' a parenteral NSAID, may be considered in this
setting Because it has no effect on the level of consciousness or pupillary reflexes. As
mentioned previously, the use of nonsteroidal analgesics may be contraindicated in some
postoperative settings when the risk of coagulopathy or hemorrhage is high, the need to
assess fever is important, or when the degree of pain is higher than the analgesic ceiling
of the agent.
Epidural opioids and/or local anesthetics can minimize the
need for systemic opioids and allow more accurate monitoring of brainstem and cerebral
function. However, a single dose of epidural morphine may produce significant blood
concentrations (Max, Inturri.si, Kaiko, Grabinski, Lit and Foley, 19X5) that in turn cause
effects within the central nervous system. A recent study could not demonstrate a
difference in neuropsychiatric functioning between patients receiving oral and epidural
morphine (Sj0gren and Banning, l989). Furthermore, motor and sensory dysfunction
associated with epidural local anesthetics (which are often coadministered with opioids)
may obscure important neurologic signs. Again, remember to balance the need for adequate
analgesia while minimizing the confounding central nervous system effects of analgesics
and anesthetics. |