← All Conditions ← Urinary Overview

Acute Kidney Injury (AKI)

★ CMTO Exam Focus

A sudden decline in kidney function occurring over hours to days, characterized by rising serum creatinine and reduced urine output. AKI occurs in 5-7% of hospital admissions and is most commonly caused by prerenal factors (reduced renal blood flow from dehydration, hemorrhage, or heart failure). Unlike CKD, AKI is potentially reversible if the cause is identified and treated promptly. Massage therapists are unlikely to treat during the acute phase but should understand recovery implications and recognize that severe or prolonged AKI can progress to chronic kidney disease.

Recognition

  • Oliguria or anuria: Reduced urine output (< 400 mL/day) or absent urine output
  • Fluid retention: Peripheral edema, facial puffiness, rapid weight gain
  • Uremic symptoms: Fatigue, nausea, confusion (accumulation of waste products)
  • Elevated blood pressure from fluid overload. Or low blood pressure if prerenal cause persists
  • Muscle cramps from electrolyte imbalances
  • Severe cases: Pericarditis, seizures, coma
  • Context: Recent hospitalization, major surgery, sepsis, nephrotoxic drug exposure (NSAIDs, aminoglycosides, contrast dye), or severe dehydration
Three categories by cause:
  • Prerenal (60-70%): Reduced renal blood flow — dehydration, hemorrhage, heart failure, sepsis. Kidneys are structurally intact but underperfused.
  • Intrinsic/Renal (25-30%): Direct kidney damage — acute tubular necrosis (ATN), glomerulonephritis, acute interstitial nephritis
  • Postrenal (5-10%): Urinary obstruction — kidney stones, BPH, tumors

MT Relevance

  • Active AKI is a contraindication: Fluid overload, electrolyte imbalances (hyperkalemia — cardiac arrest risk), and uremic symptoms make massage inappropriate during the acute phase
  • Recovery phase: With stable kidney function and physician clearance, gentle relaxation massage supports recovery and reduces stress. Use gentle pressure (tissue fragility from uremia and fluid shifts).
  • Positioning: Fluid-overloaded clients may not tolerate flat supine (pulmonary edema risk) — semi-reclined preferred
  • Deep tissue work: Avoid during recovery — electrolyte imbalances affect muscle and cardiac function
  • NSAID caution: Advise against NSAIDs for post-massage soreness — they are nephrotoxic
  • Medications: ACE inhibitors and ARBs used post-recovery cause hypotension — slow position changes

Required Actions

  • Confusion + edema + reduced urine output: Uremic encephalopathy — requires immediate medical intervention
  • Signs of hyperkalemia (muscle weakness, palpitations, cardiac irregularity): Life-threatening; emergency referral
  • Client in post-AKI recovery reports decreased urine output or new swelling: Refer back to nephrologist — possible recurrence or progression to CKD

Key Takeaways

  • AKI is a sudden decline in kidney function that is potentially reversible with prompt treatment
  • Prerenal causes (dehydration, hypotension) are the most common and most easily corrected
  • Massage is contraindicated during active AKI. Gentle treatment is appropriate post-recovery with physician clearance
  • Hyperkalemia from AKI is a life-threatening complication (cardiac arrest risk)
  • AKI can progress to chronic kidney disease if severe or prolonged

Sources

  • Werner, R. (2019). A massage therapist's guide to pathology (7th ed.). Books of Discovery.
  • Norris, T. L. (2019). Porth's essentials of pathophysiology (5th ed.). Wolters Kluwer.
  • Tortora, G. J., & Derrickson, B. H. (2021). Principles of anatomy and physiology (16th ed.). Wiley.