NTI: Pain Management Challenges

Hospitalized patients often experience pain. In the ICU, most patient experience pain to some degree. As more invasive and painful procedures are performed, pain escalates. Add in intubation, multiple lines and your patient experience a wide variety of painful sensations. How to manage this pain? What is the best pain regimen for the opioid naive and opioid-dependent patient?

Principles of Pain Assessment

Pain is a subjective complaint based on many factors:

• Procedures being performed
• Patient past medical history
• History of opioid use
• Perception of care received

Just to name a few. Assessing pain can also involve many avenues - for the verbal patient:

• Wong-Baker Pain Scale
• Faces Pain Scale
• Verbalization from the patient

It becomes more difficult to assess pain in the unresponsive patient. Patients can be unresponsive for various reasons: intubation, sedation, paralysis, dementia, psychiatric disease. However, here are some tips:

• Grimacing
• Tachycardia
• Irritability
• Decreased interaction with the environment

Opioid-Tolerant Patients

There is no exact formula to follow to ensure adequate pain management for your patients that already take opioids. The first task is to obtain information regarding the patient's past/current opioid use. Do they have cancer and take escalating doses? Are they on maintenance suboxone for past opioid addiction? Do they use street drugs? Not always easy questions to ask. If the patient is unresponsive, asking the family in a non-judgemental manner is essential. Emphasize that you want to provide optimal pain relief and in order to do so, you need to know if the patient takes opioid medication/drugs frequently.

From the Society of Hospital Medicine: "Patients with chronic pain present a special challenge. When they have pre-existing pain and undergo an operative procedure, it becomes important to differentiate pre-existing chronic pain from new acute postoperative pain. Additionally, patients already on chronic opioid therapy may require a 200 to 400 percent increase in preoperative opioid requirements.24 Thus, it is important to establish preoperative analgesic requirements to create a postoperative pain management plan, not to mention a keen awareness of comorbidities that may preclude the escalation of regimens due to patient safety concerns."

The Stepwise Approach is recommended - this involves the use of non-opioid medications such as NSAIDs, Cox-2 Inhibitors and non-pharmacological options also. However, in opioid-tolerant patients, "always start off with an immediate release medication. Long-acting opioids are not appropriate to be used to treat acute pain and for initial dose titration. The route of pain medications also makes a difference in the frequency of administering pain medications. Short-acting oral opioids peak in 45-60 minutes. Intravenous dosing will peak in 10-15 minutes. Knowing these parameters makes it easier to dose medications sooner to achieve adequate pain relief in acute pain. When dosing medications for acute pain, it is appropriate to give an additional dose if the pain is not relieved by the expected peak time.

As an example, if a patient in acute pain is given an intravenous dose, then it is appropriate to give the same dose again or double the dose (depending on the clinical situation) if there is no relief in 15 minutes once peak onset of action has been reached." (Society of Hospital Medicine)

Opioid Naive Patients

Patients that do not take opioids merit consideration also. "When using a patient-controlled analgesic (PCA) in opioid-naïve patients, only patient-controlled dosing should be used initially. Starting a continuous basal dose on an opioid-naïve patient is generally not appropriate. Once steady state is achieved with patient-controlled bolus dosing in 24 hours, then starting a continuous basal rate can be considered if the clinical judgment deems it necessary to use opioids for a longer time period." (Society of Hospital Medicine)

Other Considerations

Always be mindful of renal function as this can adversely affect pain control. Also, due to many factors, renal function can deteriorate while hospitalized. Dose adjustment must be considered. NSAIDs and Cox-2 Inhibitors are usually precluded for the patient who has decreased renal function. Patients on dialysis or CRRT also pose special pain management issues and it will be important to bring on the care of the nephrologist.

References:

Getting Out of Your Comfort Zone With Opioid Tolerant Patients

Multi-Modal Pain Strategies for the Post-Op Patient - Society of Hospital Medicine