How to manage pain in a patient with hypotension and impaired renal function on hemodialysis (HD)?

From the Guidelines

Managing pain in a hypotensive patient on hemodialysis requires careful consideration of the patient's renal function and hemodynamic status, with a focus on minimizing the risk of further blood pressure drops and adverse effects on kidney function, as highlighted in the KDIGO executive summary report 1. When treating pain in such patients, it is crucial to prioritize medications that are safe and effective, given the complexities of renal clearance and potential interactions with dialysis.

• For mild to moderate pain, acetaminophen is often considered a safer option due to its minimal effects on blood pressure and lack of need for dose adjustment in kidney disease, although the provided evidence does not specifically discuss acetaminophen, the principle of using medications with minimal renal clearance issues is implied 1.
• For moderate to severe pain, opioids may be necessary, but their use should be approached with caution, considering the risk of accumulation of active metabolites in patients with kidney disease, as well as potential hypotensive effects. The evidence suggests an adapted World Health Organization (WHO) analgesic ladder, taking into account pharmacokinetic data of analgesics in CKD, which may include conservative dosing of opioids for pain that does not respond to nonopioid analgesics 1.
• Non-pharmacological approaches, such as exercise, local heat, and relaxation techniques, should also be incorporated into the pain management plan to minimize reliance on medications with potential adverse effects.
• It is essential to avoid NSAIDs due to their potential to worsen hypotension, reduce residual kidney function, and increase bleeding risk, although this is not directly stated in the provided evidence, it is a well-established principle in managing patients with kidney disease.
• Consultation with a nephrologist is recommended to individualize pain management based on the patient's specific dialysis schedule, residual kidney function, and overall clinical condition, ensuring that the treatment plan prioritizes morbidity, mortality, and quality of life outcomes.

From the FDA Drug Label

TABLE 1 Gabapentin Tablets Dosage Based on Renal Function Renal Function Creatinine Clearance (mL/min) Total Daily Dose Range (mg/day) Dose Regimen (mg) ... Post-Hemodialysis Supplemental Dose (mg)b Hemodialysis 125b 150b 200b 250b 350b

For a patient on hemodialysis, the dosage adjustment is recommended based on creatinine clearance. The patient's hypotension is not directly addressed in the dosage adjustment, but it is essential to consider the patient's overall clinical condition when administering gabapentin.

• The post-hemodialysis supplemental dose should be administered after each 4 hours of hemodialysis.
• The maintenance dose should be based on estimates of creatinine clearance.
• It is crucial to monitor the patient's condition and adjust the dose accordingly to avoid any potential adverse effects. 2

From the Research

Treatment of Pain in Hypotensive Hemodialysis Patients

• When treating pain in patients who are hypotensive and on hemodialysis, it is essential to consider the potential effects of various medications on blood pressure 3.
• Nonsteroidal anti-inflammatory drugs (NSAIDs) may be used with caution, as they can increase blood pressure and cause kidney damage, especially with long-term use 3.
• Opioids and other non-NSAID alternatives may also be considered, but their use is associated with significant risks, including nonrenal adverse events 3.
• Antihypertensive medications, such as β and α–β blockers, angiotensin-converting enzyme inhibitors, and diuretics, may increase the risk of intradialytic hypotension (IDH) compared to calcium channel blockers 4.
• Withholding antihypertensive medications before hemodialysis is not a recommended routine practice, as it may not prevent IDH and can lead to inadequate blood pressure control 5, 6.

Management of Intradialytic Hypotension

• Intradialytic hypotension is a common complication of hemodialysis, associated with decreased quality of life, inadequate dialysis, and increased cardiovascular and all-cause mortality 5, 6.
• Lowering dialyzer blood flow is a common practice in patients who develop IDH, but its effectiveness is questionable, and it may not always reduce access blood flow or increase peripheral vascular resistance 7.
• Other strategies, such as adjusting the timing of antihypertensive medications and using vasoconstrictor medications, may be considered, but their efficacy is not well established 6.