Inadequate Pain Relief

Definition

A national survey demonstrates that 80% of postoperative patients experience pain from discharge to 2 weeks postoperatively, and 86% of those patients experience uncontrolled pain. Inadequate postoperative analgesia has significant physiologic and emotional effects for the patient and increases the health care cost burden for the system at large. There are both short-term and long-term consequences ( Table 147.1 ). Sympathetic activation in response to poor pain control increases cardiac demand and workload, which can heighten the risk of a postoperative cardiac event. Splinting and worsening ventilation/perfusion mismatch increase the risk for hypoxemia and respiratory distress. Excessive opiate use contributes to PONV and postoperative confusion. The net consequence of these risks is prolonged PACU stay, delayed discharge, lower patient satisfaction, and higher hospital admission rates.

Persistent postoperative pain, otherwise known as chronic postsurgical pain syndrome (CPSP), is an important consequence of inadequate postoperative pain relief. It is defined as pain that lasts for at least 2 months after a surgical procedure and after other pain diagnoses have been excluded. The procedures most likely to produce CPSP include limb amputation, thoracotomy, breast surgery, cholecystectomy, and inguinal hernia repair. The economic costs of both absenteeism and work performance decline are significant. A cross-sectional study of patients returning to work after a common chronic pain condition demonstrated a cost of $61.2 billion per year, mostly attributable to reduced performance.

Risk Assessment

Formulating an adequate analgesic plan for each patient involves understanding the patient’s risk for developing significant postoperative pain, for developing side effects from opiates, and assessing the risk of performing a peripheral nerve block (PNB). In addition to the procedures previously listed that are most inclined to cause CPSP, certain patient populations have a higher risk of complications related to opiates. For these groups, the best plan to optimize analgesia involves a multimodal regimen with narcotic-sparing techniques. These patient populations include the elderly, patients diagnosed with obstructive sleep apnea, and patients with preexisting pulmonary dysfunction.

The risks of the PNB need to be considered to appropriately select patients for this regimen. Absolute contraindications for PNB are as follows:

• Patient refusal. Of note, patient refusal should only occur after appropriate patient education by the anesthesiologist, which may take up to 10 to 15 minutes with some patients. It is common for some patients who initially refuse PNB to ultimately accept the block and appreciate its benefits compared with their prior general anesthesia experiences.

• Coagulopathy. Systemic anticoagulants such as warfarin should be converted to intravenous heparin injection preoperatively if PNB is indicated.

• Infection at the site of the needle placement.

• Systemic bacteremia or sepsis.

Practically speaking, all of these conditions are highly unlikely in outpatients presenting for same-day orthopedic surgery. Preexisting neurologic problems may sometimes be relative contraindications for PNB; careful documentation of the neurologic condition is mandatory when PNBs are performed in such a situation.