Use of hypertonic sodium phosphate enemas (ie Fleet) in the elderly may cause severe phosphate neuropathy and hyperphosphatemia.
Deposits of phosphate crystals form within the kidneys causing kidney dysfunction. Sodium phosphate is absorbed into the blood stream due to the significant absorption properties found in the bowel.
Cleansing enemas are used in hospitals for pre operative bowel preparation and when bowel activity has not occurred for many days and the risk of bowel obstruction is real. First line treatment should always be non pharmacological. In addition to strategies below patients should be provided with opportunities to sit on a toilet/commode regularly (at least daily particularly postprandially).
- patient education
Enemas distend the bowel stimulating colon contractibility causing stool expulsion. Phosphate enemas additionally stimulate the bowel muscles to contract facilitating stool expulsion. Adverse effects for all enemas irrespective of the active ingredient includes electrolyte imbalance (metabolic derangement) and bowel perforation.
Bowel perforation can generally be related to muscle weakness of the bowel wall, an obstruction or incorrect positioning of the patient during enema administration. Bowel perforation, hyperphosphatemia and phosphate neuropathy may occur, causing death in up to 4% of cases post enema administration.
Symptoms of acute phosphate nephropathy are:
- decreased urination
- swelling of ankles, feet and legs.
Symptoms of hyperphosphatemia potentially are:
- muscle cramps
- joint pain
- tingling and numbness
and in prolonged states:
- itchy skin
- skin rashes
Patient groups at risk for phosphate neuropathy and hyperphosphatemia are:
- aged > 65 years
and patients with
- bowel obstruction, delayed bowel emptying or active colitis and
- on medications (diuretics, angiotensin converting enzyme [ACE] inhibitors, angiotensin, receptor blockers [ARBs], non inflammatories ( NSAIDs) and analgesics (opiates)
Preventing constipation particularly post operatively is vitally important. Being aware of your patients usual bowel habits and routines provides a baseline for the development of their bowel management plan.
“A stitch in times saves nine”
Negating the need to consider the use of enemas is a primary role of the nurse. Asking your patient “have your bowels moved today” is not a rhetorical question. Enquiring about the bowel activities of your patients is only the first step in preventing constipation. Doing something about lack of bowel movements is necessary.
Caution in use of phosphate based enemas for bowel cleansing pre procedure or for treatment of constipation is highly recommended. If administration is prescribed then nurses must be aware of patients at risk for hyperphosphatemia and phosphate neuropathy. Initiating a conversation with the prescriber regards the risks and clinical reasoning for your particular patient is necessary for their safety and wellbeing.