UCLA Pain Management Resource

Patient Guidelines for Inpatient Pain Management

Assessing Pain

Pain should be assessed both at rest and with activity. Objective pain scores are usually used, such as a verbal pain score from 0 to 10. An objective score out of 10 can be related to the severity of pain, for example, as: 1-3 = mild pain, 4-7 = moderate pain, 8-10 = severe pain. Documenting characteristics of pain (sharp, dull, constant, intermittent, precipitating or alleviating factors) can aid therapy. To assess pain with activity, ask patients to rate pain with coughing, breathing deeply, or ambulating. For many patients, effective analgesia with activity is critical to recovery and discharge. For instance, a postoperative patient who stays bedridden and avoids coughing and breathing deeply due to postsurgical abdominal pain may have an increased risk of developing pulmonary complications.

Selection of pain medications by pain severity

The classes of medication selected for pain control may depend on the severity of pain at its peak.

  • Mild pain is treated by NSAID or acetaminophen (with non-opioid adjuvant as appropriate).
  • Moderate pain is treated with opioid, plus adjuvant scheduled NSAID or acetaminophen (or other adjuvant as appropriate).
  • Severe pain is treated with opioid and adjuvants as with moderate pain. Consider special modalities, such as epidural analgesia, peripheral nerve blockade.

The route of administration (e.g., PO or IV) for systemic medications does not depend on the pain severity.

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NSAID therapy

Nonsteroidal anti-inflammatory drugs (NSAID’s) should be used for acute pain management in most patients without a specific contraindication to their use. Contraindications include peptic ulcer disease, GI bleeding, coagulopathy, and hepatic disease, renal insufficiency. Potent NSAID therapy, such as IV ketorolac or high-dose rofecoxib (50 mg/d), should be used for short durations (3-5 days). On such regimens, elderly patients may benefit from monitoring of the creatinine level.

Consider the effects of NSAID’s on platelet function and osteogenic activity in surgical patients. These effects and alteration of gastric mucosa homeostasis are less pronounced with the newer COX-2-selective agents, such as rofecoxib and celecoxib. Patients with ongoing postoperative bleeding, hypovolemia, or prerenal azotemia should not be given NSAID’s until these conditions resolve.

NSAID dosing regimens:
  • Ibuprofen 600 mg PO QID
  • Rofecoxib 50 mg PO QD x 5d, then 25 mg PO QD
  • Celecoxib 400mg PO x 1, then after 12 h start up to 200 mg PO BID
  • Ketorolac 30-60 mg IV loading dose, then 15-30 mg IV q6h x 3-5 d
(15 mg loading dose in elderly patients)

Acetaminophen, a central inhibitor of prostaglandin synthesis without significant peripheral inhibition, may be used in many patients with problems taking other NSAID’s, especially when GI disturbance or platelet effects limit their use. Acetaminophen may be given in doses limited to 4 g/day in adults, such as 650 mg PO q4h. It should be used with caution in patients with liver disease and patients with induction of the P-450 enzyme system, as with acute alcohol intoxication.

All NSAID therapy should usually be ordered on a regular schedule, not on a "PRN" basis. Use of NSAID’s can substantially reduce the opioid requirements of patients with moderate to severe pain, and can make an opioid regimen that is otherwise inadequate for severe pain work sufficiently.

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Opioid therapy

  • Give opioid scheduled around-the-clock instead of "prn."
  • Order different opioid doses for mild, moderate, and severe pain.
  • Hold for excessive sedation or respiratory depression.
  • Observe response to initial regimen, and titrate accordingly.
  • For moderate and severe pain, keep opioid separate from NSAID or acetaminophen dosing. (Avoid combination drugs.)

For IV opioid therapy, use PCA mode as described below.

Initial IV PCA settings:
  • Morphine
    • Demand (bolus) dose: 0.5-2 mg
    • Time interval (frequency): q5-12 minutes
    • Basal rate: None
    • Hourly maximum: 8-15 mg/hr
  • Hydromorphone
    • Demand (bolus) dose: 0.1-0.4 mg
    • Time interval (frequency): q4-10 minutes
    • Basal rate: None
    • Hourly Maximum: 2-3mg/hr
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Clinical pearls for IV PCA management

  • Selecting initial PCA settings. The settings described above can be used initially. If a patient has IV PCA started after surgery, the settings can be adjusted based on the patient’s response to IV opioid boluses in the PACU. Otherwise, an initial opioid bolus can be used to evaluate the patient’s individual response. Appropriate PCA settings may not allow a patient to receive as many doses per hour as the lockout interval would permit without an hourly maximum limit. A higher demand dose may be selected if necessary because the total opioid received will be limited. In general, younger patients and opioid-tolerant patients have higher opioid requirements than patients who are older and opioid-naïve.
  • Do not check "ROUTINE" for 1-Hour maximum amount. A "routine" protocol for the Hourly Maximum setting has not been established at UCLA, and this option will soon be removed from the PCA order sheet. The routine is at the discretion of the nurse who programs the pump. The patient’s age, recent history of opioid use, and response to recent doses of opioids should be considered in selecting the hourly maximum. The hourly maximum setting may not relate directly to the Dose and Lockout Interval.
  • Basal infusion. An occasional patient may benefit from having a low-rate (e.g., 1mg/h morphine) basal infusion at night to prevent sleep interruption from pain or from receiving a constant basal infusion when opioid use is unusually high. However, the decision to use a basal infusion must be carefully considered, since little scientific evidence exists to support use of a basal infusion, and a basal rate lessens the intrinsic safety of the PCA system in avoiding opioid overdose.
  • What to do for inadequate analgesia. Assess the history from the PCA pump. If the number of attempts is more than 3 times the number on injections and the patient is not bradypneic or oversedated, the demand dose may be increased or the lockout interval may be decreased. Often such changes do not require a change in the hourly maximum setting.
    • If the patient is getting < 4 doses/hour, ask the patient about PCA use. If the patient is intentionally not using the PCA due to perceived lack of efficacy, consider increasing the demand dose or decreasing the lockout interval. If the patient is minimizing the PCA use due to side effects such as itching, nausea, or constipation, treat the side effects. If the patient does not seem able to use the PCA appropriately, consider other alternatives or using adjuvant therapy in addition to IV PCA.
    • Some patients with inadequate analgesia or intolerable side effects with one opioid will do better with a different opioid.
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Conversion from IV to PO opioid

When converting between enteral and parenteral routes of opioid administration, use 24-hour equivalent doses to guide specific dosing. (See Principles of Analgesic Use in the Treatment of Acute Pain and Cancer Pain for conversion.) First, the daily parenteral opioid use is estimated from the medication records. Then a conversion table specifying relative potencies of opioids in parenteral and PO forms is used to calculate the theoretical daily PO equivalent opioid dose. A patient may receive a PO form of the same opioid medication that was used IV, or a different medication may be selected.

IV-to-PO equivalents are approximations. Thus, the calculated PO equivalent may be too high, and the actual dose given to the patient should be reduced to 1/2 to 2/3 of the calculated PO dose. For instance, if a patient has received effective analgesia with 120 mg/d IV morphine, the equivalent dose of oral oxycodone is 240 mg/d PO. 2/3 of this amount is 180 mg/d PO. This amount can be given in divided doses in q3h intervals, and use of sustained-release oxycodone for 1/3 to 1/2 of the total daily dose may be considered. Further dose adjustment should be made based on patient response.

For pain that varies in intensity, dosing can be ordered with a different dose for mild, moderate, and severe pain. For example:

Oxycodone PO q3h around-the-clock:
  • For mild pain, 10 mg
  • For moderate pain, 20 mg
  • For severe pain, 30 mg
  • Hold for excessive sedation or resp. rate < 10.
  • Pt. may refuse.

If the patient consistently receives the dose for severe pain and has inadequate analgesia, increase the dose or add an analgesic adjuvant. If the patient becomes oversedated or requires infrequent dosing, decrease the dose.

Patients unable to take PO regimen

Consider IV ketorolac or rectal acetaminophen. For opioid therapy, use IV or transdermal route of administration.

Discharging patients on adequate analgesic regimen

Use NSAID for all patients unless a specific contraindication exists. Use acetaminophen if NSAID is contraindicated. Give these medications scheduled, around-the-clock.

Give opioid regimen individualized for the patient. Confirm that discharge regimen is adequate before discharge by observing patient on the discharge regimen for at least six hours, preferably 24 hours. Vicodin alone does not work for everyone.

If patients are admitted on chronic opioid therapy, plan for discharge on appropriate opioid regimen, not simply Vicodin. Ensure each service’s ability to provide triplicate prescriptions when needed.

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Epidural analgesia

Patients undergoing abdominal surgery may benefit from epidural analgesia in two ways. Patients with upper abdominal incisions, including midline and subcostal incisions, can receive markedly better analgesia with epidural infusion of local anesthetic plus opioid than with systemic analgesics alone. This is especially true in the treatment of active pain. Some patients will not complain of severe pain when lying quietly in bed but will avoid breathing deeply, coughing, and getting out of bed due to intractable pain. Epidural analgesia usually provides better relief of active pain for these patients. Many patients with lower abdominal incisions do better with epidural analgesia as well.

The other major benefit of epidural analgesia after abdominal surgery is a quicker return of gastrointestinal motility. If patients with epidural analgesia are managed aggressively with early NG tube removal and early feeding, they demonstrate quicker return of normal bowel function and potentially quicker discharge to home than with systemic analgesia. The reasons for this effect are: 1) segmental sympathectomy from epidural local anesthetic increases peristalsis via enhanced parasympathetic outflow and 2) effects of systemic opioid on GI motility are reduced. Surgical patients with anticipated postoperative ileus are good candidates for epidural analgesia.

Patients undergoing thoracotomy incision often receive epidural analgesia because the excellent pain relief provided can be critical to early ambulation and to preserving the ability to cough effectively and breathe deeply. Patients undergoing thoracotomy are at risk for postsurgical pulmonary complications, and effective analgesia may reduce this risk. Epidural analgesia may reduce the long-term development of post-thoracotomy pain syndrome.

Most patients with epidural analgesia should receive concomitant NSAID therapy unless it is specifically contraindicated. Adjuvant NSAID use can improve analgesia compared to epidural infusion alone and can greatly reduce the shoulder or upper back pain that often follows thoracotomy without increasing sedation. If peripheral-acting NSAID’s are not indicated, intermittent IV opioid with or without acetaminophen can be used for this pain.

If epidural analgesia is contraindicated or impractical, intercostal nerve blockade can provide analgesia for patients undergoing abdominal or thoracic surgery. Unless repeated, intercostal blocks provide only 8-12 h of analgesia.

Epidural analgesia may also be used after lower extremity surgery, such as knee replacement, hip replacement, or lower extremity revascularization, and is also effective for many patients after major spine surgery. Use of epidural analgesia may reduce the risk of thromboembolic complications after major surgery of the lower extremities such as joint replacement. Patients with multiple rib fractures after blunt chest trauma often ambulate, breathe deeply, and cough better with epidural pain relief.

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