Fleet Enema Can Significantly Worsen Acute Kidney Injury
Fleet (sodium phosphate) enemas should be avoided in patients with acute kidney injury as they can cause severe hyperphosphatemia, hypocalcemia, and further deterioration of renal function.
Mechanism of Harm
Fleet enemas contain sodium phosphate, which can be absorbed systemically, particularly in patients with compromised renal function. When administered to patients with AKI:
- Phosphate absorption is increased due to impaired renal excretion
- Hyperphosphatemia develops rapidly
- Reciprocal hypocalcemia can occur, potentially leading to tetany or coma
- Calcium-phosphate precipitation in renal tubules can worsen existing kidney injury
Evidence for Harm
Case reports and clinical experience demonstrate that sodium phosphate enemas can cause serious complications in patients with renal dysfunction:
- Severe hyperphosphatemia and hypocalcemic coma have been documented in elderly patients with chronic renal failure who received Fleet enemas 1
- Both acute and chronic kidney injury patterns have been observed following sodium phosphate administration, with most patients experiencing irreversible loss of renal function 2
- Elderly patients are at particularly high risk due to decreased glomerular filtration rate, concomitant medication use, and systemic/gastrointestinal diseases 3
Risk Factors for Complications
The risk of adverse effects from Fleet enemas is higher in patients with:
- Pre-existing renal dysfunction (including AKI)
- Advanced age
- Bowel obstruction
- Small intestinal disorders
- Poor gut motility
- Dehydration
- Electrolyte imbalances
Alternative Options
For patients with AKI requiring bowel evacuation:
- Simple tap water enemas
- Normal saline enemas
- Glycerin suppositories
- Polyethylene glycol (PEG) solutions (when oral preparation is needed)
Management of Patients Exposed to Fleet Enemas with AKI
If a patient with AKI has already received a Fleet enema:
- Monitor serum phosphate, calcium, and renal function closely
- Treat hyperphosphatemia if present
- Administer calcium if symptomatic hypocalcemia develops
- Ensure adequate hydration (if not contraindicated by volume status)
- Consider renal replacement therapy if severe electrolyte abnormalities develop
Nephrotoxic Medication Management in AKI
The ADQI consensus recommends avoiding nephrotoxic medications whenever possible in patients with AKI 4. This principle applies to Fleet enemas, which should be considered potentially nephrotoxic in the setting of kidney injury.
Conclusion
While one large database study suggested no increased risk of AKI with oral sodium phosphate preparations for colonoscopy in the general population 5, this finding cannot be extrapolated to patients who already have AKI. The preponderance of evidence and clinical guidelines support avoiding Fleet enemas in patients with acute kidney injury due to the risk of worsening renal function and potentially life-threatening electrolyte abnormalities.