Authors: Rebecca Fisher MD, Timothy F. Platts-Mills MD MSc

Edited By: Angel Li MD; Shan Liu MD, SD

Updated: 9/24/2021

Case Study

A 75-year-old male presents with acute-on-chronic back pain. He had been sleeping in a recliner at his daughter’s house for the past few nights, and now is complaining of worsening low back pain. Vital signs: Temp: 37*C, BP: 118/75, RR: 18, HR: 105, O2: 98% on room air. He is alert and oriented, and denies any recent trauma. He takes hydrocodone/tylenol (Norco) 5-325 mg, which is prescribed by his primary care physician, to help with pain. He took an extra one today but it did not provide any relief and he rates his pain at 9 out of 10. He denies saddle anesthesia or incontinence, and states he is having some difficulty with ambulation secondary to the pain. His other medications include a daily baby aspirin, lisinopril, and lasix.

Objectives

By the end of this module, the student will be able to: 

1. List common analgesics used in the ED
2. Discuss the advantages and disadvantages of different analgesics when considering the geriatric population
3. Understand the Beers list from the American Geriatrics Society and be familiar with common analgesics on the list

Introduction

Pain is a common chief complaint in the ED and is commonly undertreated in older adults. Extra consideration must be taken with pain management in older adults due to the physiologic changes that occur as aging occurs. Older adults are already on multiple medications, causing potential drug interactions and have comorbidities that affect the metabolism of pain medications.

Special care should be taken to identify and alleviate pain in patients with cognitive impairment, as they may not be able to state that they are in pain or which specific part of their body is hurting. Be aware of non-verbal cues, such as grimacing, guarding, or localizing pain. In patients with cognitive impairment, agitation may be the sole manifestation of pain. Observations from family or caregivers may be needed to understand a change from their baseline regarding agitation or other behaviors. Pain management in agitated patients should be considered before other medications to manage behavior such as sedative-hypnotics, antipsychotics or dissociative anesthetic (such as ketamine). Tools (eg, PAINAD) have been developed to measure pain in these patients. However, none have been validated in the ED.

The Beers Criteria Medication List was developed using evidence-based justification in 1991 by the American Geriatrics Society as a resource for medications to avoid in the older adult population. It was most recently updated in 2019. Many commonly used analgesics are on the Beers Criteria Medication List.

In 1986, the World Health Organization developed the WHO analgesic ladder to improve care for cancer patients. Since then, it has been expanded to help treat a variety of painful conditions. Updates have focused on quality of life, and recommendations for acute pain including starting with a stronger analgesic and tapering down.

Analgesics

Acute pain should be quickly addressed and closely monitored. All patients should be re-assessed for pain control no more than 20 to 30 minutes after medication administration.

For mild to moderate pain, consider starting with nonpharmacologic therapy. Offer a patient a cold compress or ice pack, along with elevation if the pain localizes to an extremity. While a warm compress might be more difficult to obtain in an ED, a warm blanket could act as a temporary substitute.

Mild Pain

Acetaminophen is generally considered safe to use in the older adult population. Dosing can go as high as 1,000 mg every 6 hours, but be sure to determine if the patient has taken any pain medication prior to arrival so more than 1,000 mg total is not given within 6 hours. For patients with liver disease, the maximum daily dose is reduced from 4,000 mg to 3,000 mg.

Be cautious with non-steroidal anti-inflammatory medications (NSAIDs), as they have an increased risk of adverse effects such as gastrointestinal bleeding, renal dysfunction, and platelet dysfunction. These medications include ibuprofen, naproxen, and ketorolac. They are included on the Beers Criteria Medication List. However, topical NSAIDs can be used for short durations, as they have low systemic absorption. When choosing to start a patient on NSAIDs for pain management, consider adding a proton-pump inhibitor to avoid gastric irritation (even when administered parenterally). Caution should be used in patients who are on an aspirin regimen, as NSAIDs have been shown to inhibit the anti-platelet effect of aspirin. Caution also should be taken using NSAIDs in patients using ACE Inhibitors or taking metformin due to the risk of renal failure and lactic acidosis, respectively. NSAIDs should not be used for more than three days in patients taking these medications.

Topical medications, such as lidoderm patches or diclofenac gel, can be helpful for patients complaining of musculoskeletal pain as they also have low systemic absorption. Use caution when sending patients home with topical medications such as patches, since patients with cognitive impairment may forget to take the original patch off and continue placing additional patches on their body. Systemic side effects are less common from topical NSAIDs than with oral NSAIDs, but can still occur.

Table 1 (Ref. 5)

Moderate Pain

With worsening pain, or pain that is not controlled with over the counter medications such as acetaminophen, consider starting with a weaker opiate. These include medications such as hydrocodone, tramadol, and codeine. These can be given in combination with other medications, and often come combined like hydrocodone and acetaminophen (Norco, Vicodin) or codeine and acetaminophen (Tylenol #3,  #4).

Tramadol was added to the Beers Criteria Medication List in 2019 as it has been associated with hyponatremia and syndrome of inappropriate antidiuretic hormone secretion. This may not be the best first choice for pain, as patients might not find it as potent and the risks can outweigh the benefits.  Usage should be carefully weighed given concerns regarding adverse effects such as drowsiness, constipation, and lowering seizure thresholds.

Additional medication options for moderate pain include low dose oxycodone. If the patient is unable to tolerate PO medications, consider fentanyl. Fentanyl has a fast onset of action, along with a shorter half-life than other parenteral opiates, but keep in mind this also means it has a shorter duration of action. 

When starting opiate medications, start with a low dose and titrate up. It is not as difficult to add additional medication as it is to try to take away medication once a patient has received too much! Also, provide patients with dietary recommendations (eg, prune juice) or prescriptions for a bowel regimen. Constipation is the most commonly reported adverse effect of opioids and can impair function and result in an avoidable trip to the emergency department.

If moderate pain is not well controlled by these medications, then lower doses of stronger opiates should be considered.

Severe Pain

In patients with severe pain, it is not unreasonable to start with parenteral opiates such as fentanyl, morphine, or hydromorphone. Use weight based dosing and consider starting doses 25-50% lower than what would typically be used in younger adults. Additional doses can be given, as soon as 15 minutes after initial administration, if pain is still not well controlled.

Since morphine is metabolized by the kidneys, this is the best choice for pain management in patients with a history of liver dysfunction. Fentanyl and hydromorphone are metabolized by the liver, so these medications are a better choice in patients who have renal dysfunction.

If the patient is able to tolerate PO medications, higher doses of oxycodone can be administered. Oxycodone has few toxic metabolites, along with a shorter half-life than other opiate medications. 

As mentioned with moderate pain control, consider starting patients on a bowel regimen whether they are being admitted or discharged.

Regional anesthesia, also known as nerve blocks, can be helpful in providing pain control for extremity injuries such as hip fractures. Using a long acting anesthetic such as bupivacaine can provide greater relief with fewer systemic adverse effects. 

FOAMed resources:

Ultrasound Guided Femoral Nerve Block 

http://www.emdocs.net/ultrasound-guided-femoral-nerve-block/

Duke Anesthesiology – Vide on femoral and lateral cutaneous nerve block 

https://www.youtube.com/watch?v=TOcvCKr9J18

Table 2 (Ref. 5)

Behavioral Interventions

For patients with chronic pain, non-pharmacologic interventions can help reduce pain symptoms and improve function and quality of life. Physical activity in general (eg, walking) and specific forms of physical activity, such as mind-body exercises (eg, Yoga, Tai Chi) improve pain, mood, and functional status. Senior community centers often offer low impact exercise classes such as water aerobics or spin classes that can be especially helpful for patients with chronic low back pain. For patients with limited resources or limited access to formal exercise programs, walking just 30 minutes twice a day can improve overall well-being after an acute-on-chronic pain episode has resolved. For patients whose mobility is limited due to an injury or pain condition, a physical therapist can help the patient improve the function of the injured body part and also adapt movements so that they can remain physically active and preserve their functional independence. Patients with limited mobility may also benefit from regular repositioning and passive range of motion exercises, along with meditation and deep breathing exercises. Cognitive-behavioral therapy can help patients better handle the stressors associated with chronic pain and identify and address unhealthy coping strategies.

Pearls and Pitfalls

• Acetaminophen is generally the safest initial choice for pain management if a patient is in mild/moderate pain and able to tolerate PO intake.
• Avoid NSAIDs in patients with a history of kidney disease or on other medications that affect the kidneys.
• For patients with severe pain but who are able to tolerate PO intake, consider oxycodone.
• For patients discharged on opioid, provide dietary recommendations or medications to avoid constipation.
• Behavioral interventions such as physical activity (eg, walking), social support, and meditation or deep breathing exercises can be important primary or adjunct therapies to reduce pain and support recovery. 
• For patients with musculoskeletal pain that impairs function, physical therapy may accelerate return to normal activity and reduce the psychological impact of pain symptoms.

Case Study Resolution

The patient had taken a total of 10-650 mg hydrocodone-acetaminophen, so caution needs to be taken with additional acetaminophen dosing. Given his other home medications (aspirin, lasix, lisinopril), NSAIDs should be avoided. A dose of 7.5-325 mg of hydrocodone-acetaminophen was given along with a lidoderm patch placed on both sides of his lower back. After 25 minutes, he reports his pain has only improved to 7 out of 10. Morphine 4 mg IV is ordered, and upon re-evaluation he reports that his pain has significantly improved and he is now able to ambulate with some discomfort. He is discharged home with a prescription for lidocaine patches and a 3 day supply of extra 5-325 mg hydrocodone-acetaminophen to help manage his acute pain. Colace was recommended to prevent constipation.  He is also encouraged to ambulate for at least 10 minute three times a day and try to spend time in a swimming pool once a day to increase his physical activity. He is instructed to follow up with his PCP in the next 2 days and given a referral for physical therapy.

References

1. American College of Emergency Physicians. “Sub-dissociative Dose Ketamine for Analgesia” Policy Resource and Education Paper. Approved October 2017.
2. By the 2019 American Geriatrics Society Beers Criteria® Update Expert Panel. American Geriatrics Society 2019 Updated AGS Beers Criteria® for Potentially Inappropriate Medication Use in Older Adults. J Am Geriatr Soc. 2019 Apr;67(4):674-694. doi: 10.1111/jgs.15767. Epub 2019 Jan 29. PMID: 30693946.
3. Anekar AA, Cascella M. WHO Analgesic Ladder. [Updated 2020 May 17]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK554435/
4. Harper, G. Michael, et al. GRS: Geriatrics Review Syllabus. American Geriatrics Society, 2019. 
5. Hwang U, Platts-Mills TF. Acute pain management in older adults in the emergency department. Clin Geriatr Med. 2013 Feb;29(1):151-64. doi: 10.1016/j.cger.2012.10.006. PMID: 23177605.