| Back surgery. Operations on the spine at any level are frequently done in patients who have
experienced chronic pain. Such patients may have the typical complications of chronic
pain: depression, anxiety, irritability, and if opioid analgesics were required
preoperatively, a relative tolerance to opioid medications. All of these factors may
complicate pain assessment and treatment in the postoperative period. In addition, the
majority of procedures requiring a spinal operation are associated with paraspinal muscle
spasm. In such cases, it is appropriate to add muscle relaxants to supplement conventional
opioid therapy.
Operations on the spinal cord often involve laminectomy and
bone grafting and may include opening the aura around the spinal cord. These procedures
may limit the role of epidural and spinal delivery of pain medications. As with any
neurologic procedure, postoperative patients require careful monitoring of neurologic
functions, especially the assessment of sensory, motor, and autonomic functioning.
Surgery on extremities (orthopedic, vascular).
Many common operations performed on extremities are elective
and include total joint replacements. The high degree of morbidity related to venous
thromboembolic complications must be considered. Pain control postoperatively should allow
early ambulation and movement in the postoperative period. Supplementing conventional
opioids with an epidural infusion of a local anesthetic may benefit these patients by
decreasing the incidence of thromboembolism. Operations requiring a cast or other form of
external fixation for stabilization demand frequent postoperative evaluation of
circulation and neurologic functions. Pain therapy should not interfere with monitoring
the patient.
Orthopedic or vascular procedures on an extremity may result
in a compartment syndrome; this is usually associated with a period of ischemia or perhaps
injury to the muscles of the lower extremity. It is manifested by intracompartmental
swelling with loss of function, the earliest manifestation being loss of dorsiflexion of
the foot and pain. Once again, this requires continuous observation; pain control measures
should not mask this process. If not treated promptly by decompression, a compartment
syndrome may result in chronic postischemic neuropathy.
The traumatic amputation is often associated with phantom
limb pain. Evidence now exists that infusion of epidural local anesthetic prior to
elective amputation for inoperative vascular disease can minimize this symptom (Bach,
Noreng, and Tjellden, 1988); the applicability of these pilot data to treatment of other
conditions or trauma remains to be defined.
The majority of operative procedures on extremities produce
pain of moderate intensity usually controlled by early parenteral opioids supplemented by
NSAIDs. Adding epidural analgesia is particularly attractive in terms of establishing
early mobility and minimizing thromboembolic complications (Guideline Report, in press;
Modig, Borg, Bagge, and Saldeen, 1983; Modig, Borg, Karlstrom, Maripuu, and Sahlstedt,
1983; Pettine, Wedel, Cabanela, and Weeks, 1989).
Soft Tissue Surgery
Surgical procedures involving local soft tissue resections
usually obtain pain control with oral opioids. Many of these procedures are done on an
ambulatory basis and require careful patient education prior to and immediately after the
procedure. Anxiety because of the potential results of a small surgical biopsy (e.g.,
feared results of a breast biopsy) may demand adjuvant drug or nondrug therapy. Pre- and
postoperative education and support by the surgeon and the health care team are supremely
important. |