Enema-induced hyperphosphatemia

Sodium phosphate does not increase risk for acute kidney injury after routine colonoscopy, compared with polyethylene glycol

BACKGROUND & AIMS

Oral sodium phosphate (OSP) is a common bowel purgative administered before colonoscopy; the Food and Drug Administration has warned against its use because of concerns about acute kidney injury (AKI) from the absorbed phosphate and dystrophic calcification. However, it is not clear if OSP is associated with AKI in the general population or in high-risk subgroups undergoing colonoscopy. We estimated the risk of AKI among patients undergoing a screening colonoscopy using OSP vs polyethylene glycol (PEG) for bowel cleansing in a large, US-based claims database.

METHODS

We used an insurance database to identify a cohort of patients ages 50 to 75 years who underwent screening colonoscopies as outpatients from January 2000 through November 2008 (before the Food and Drug Administration warning), receiving OSP (n = 121,266) or PEG (n = 429,430) within 30 days beforehand, without prior use of either drug. We collected data from patients for 6 months afterward to identify those who developed AKI or renal failure, or received dialysis. Adjusted and propensity score-matched hazard ratios (HR) and 95% confidence intervals (CI) were estimated using Cox proportional hazards models. We investigated the effects in subgroups with higher AKI risk (patients with chronic kidney disease, kidney stones, hypertension, or diabetes, or using antihypertensive or nonsteroidal anti-inflammatory drugs).

RESULTS

AKI occurred in 0.2% of OSP users and in 0.3% of PEG users (adjusted HR, 0.86; 95% CI, 0.75-0.99). OSP users matched well with PEG users, producing similar estimates (HR, 0.85; 95% CI, 0.72-1.01). We did not observe a consistent increase in the risk of AKI or other outcomes in any subgroups analyzed.

CONCLUSIONS

In a large database analysis, we did not associate administration of OSP before colonoscopy with increased risk of postprocedure AKI, even in high-risk clinical subgroups.

Effects of a 250-mL enema containing sodium phosphate on electrolyte concentrations in healthy volunteers: An open-label, randomized, controlled, two-period, crossover clinical trial

BACKGROUND

Enemas are used by individuals with constipation and are often required before certain medical diagnostic procedures and surgical interventions. However, abnormalities in serum electrolyte concentrations have been associated with enema use.

OBJECTIVE

The aim of this study was to determine the changes in serum electrolyte concentrations (phosphorus, calcium, sodium, and potassium) and urinary phosphorus elimination after the administration of a sodium phosphate enema.

METHODS

Healthy volunteers aged 35 to 70 years were eligible for this open-label, randomized, controlled, 2-period, crossover clinical trial at the Clinical Research Unit of the University Hospital of Navarra, Pamplona, Spain. The study comprised 2 one-day periods separated by a 7-day washout. All subjects were randomly assigned in a 1:1 ratio to 1 of 2 study sequences: (1) a single dose of Enema Casen® 250 mL in the first period followed by no treatment (control) in the second period, or (2) no treatment in the first period followed by a single dose of the study drug in the second period. The sequence of treatment was assigned using a randomization table that was prepared before the beginning of the study. Serum concentrations of phosphorus, sodium, potassium, and calcium were measured in both periods. Urinary phosphorus elimination was measured for 12 hours after enema administration (Ae0-12) in a subset of the subjects in the second period. Adverse events (AEs) were monitored by the investigators throughout the study. Normal ranges for the electrolytes were as follows: phosphorus, 2.5 to 5 mg/dL; calcium, 8.5 to 10.5 mg/dL; sodium, 135 to 145 mEq/L; and potassium, 3.5 to 5 mEq/L.

RESULTS

Twenty-four subjects (12 men, 12 women; mean [SD] age, 47.8 [9.6] years [range, 36-68 years]) participated in the study. All of the subjects were white and none were smokers. Twelve hours after enema administration, mean serum phosphorus and sodium concentrations increased by a mean of 1.18 mg/dL and 1.32 mEq/L, respectively (both, P < 0.001). Mean serum phosphorus concentrations were above the upper limit of normal (5 mg/dL) at 30 and 60 minutes after enema administration. In all subjects the values returned to normal within 4 hours after enema administration; a meal was provided after a 3-hour fast. Four subjects (16.7%) had ≥1 serum phosphorus concentration measurement ≥7 mg/dL, a value that is considered serious hyperphosphatemia. A statistically significant correlation was found between phosphorus Cmax and enema retention time (r (2) = 0.452; P < 0.001). No abnormal serum concentrations were obtained for the other electrolytes measured. Phosphorus Ae0-12 was increased after enema administration by 86% (P < 0.001). No serious AEs were observed, although 13 AEs were reported in 9 subjects. None of the changes in serum electrolyte concentrations were associated with clinical symptoms.

CONCLUSIONS

Administration of an enema containing 250 mL of sodium phosphate was associated with serum phosphorus concentrations of ≥7 mg/dL in 16.7% of the healthy subjects who participated in the study; however, none of those subjects experienced hypocalcemia. Enema retention time was significantly correlated with the degree of phosphatemia.

Serum electrolyte shifts following administration of sodium phosphates enema

The misuse of sodium phosphates enemas has resulted in reports of potentially severe metabolic and hemodynamic disturbances. Despite their long availability, these products have not been fully characterized pharmacokinetically. This trial sought to evaluate changes in the metabolic and hemodynamic parameters following the administration of one of two standard sodium phosphates enemas. Enema Casen (250 ml) is available only in Spain, and Fleet Enema (133 ml) is available in 66 countries in six continents of the world. These changes were correlated with scientific literature reports of hyperphosphatemia following phosphate enema use. Forty-five adult participants aged 50 years or older enrolled in the trial. Twenty-five participants were given one Enema Casen, whereas 20 participants received one Fleet Enema. Blood pressure, pulse, and serum chemistries were evaluated at screening; baseline; and 10, 60, and 120 minutes after receiving the enema. Each participant had a bowel movement within 10 minutes of receiving his enema. Asymptomatic, transient hyperphosphatemia was associated with increase in retention time but not with increase in volume of sodium phosphates enemas. Increased serum phosphate concentration and increased area under the curve of serum phosphate were associated with increased enema retention time. The Enema Casen induced a greater mean AUC of serum sodium concentration than did the Fleet Enema. There were no drug-related adverse events. Transient hyperphosphatemia following the use of sodium phosphates enemas correlates with retention time but not with dose. A scientific literature review of serious adverse events revealed that overdose, concomitant use of oral and rectal sodium phosphates products, and use in a contraindicated patient were associated with sodium phosphates enema and hyperphosphatemia.

Forensic application of ESEM and XRF-EDS techniques to a fatal case of sodium phosphate enema intoxication

Sodium phosphate enemas and laxatives are widely used for the treatment of constipation, even if a number of cases of significant toxicity due to alterations of the fluid and electrolyte equilibria (hypernatremia, hyperphosphatemia, and hypocalcemia) have been reported. We present the case of an 83-year-old man who died of fecal and chemical peritonitis secondary to an iatrogenic colon perforation (produced performing a Fleet enema through the patient's iliac colostomy) with peritoneal absorption of sodium phosphate. Environmental scanning electron microscopy coupled with an X-ray fluorescence energy dispersive spectrometry discovered multiple bright crystals formed of calcium, phosphorus, and oxygen in the brain, heart, lung, and kidney sections of the victim. The absence of these kinds of precipitates in two control samples chronically treated with Fleet enemas led us to assume that the deceased had adsorbed a great quantity of phosphorus ions from the peritoneal cavity with subsequent systemic dissemination and precipitation of calcium phosphate bindings.

Adverse renal and metabolic effects associated with oral sodium phosphate bowel preparation

Colorectal cancer can be prevented by the removal of adenomatous polyps during screening colonoscopy, but adequate bowel preparation is required. Oral sodium phosphate (OSP), an effective bowel purgative, is available over the counter and requires a substantially lower volume than polyethylene glycol-based preparative agents. Accumulating reports implicate OSP in electrolyte disturbances as well as acute kidney injury (AKI) in a syndrome termed phosphate nephropathy (a form of nephrocalcinosis). Despite published case reports and case series, the actual incidence, risk factors, and natural history of phosphate nephropathy remain largely undefined. Several recent observational studies have provided new information on these important issues while supporting a link between OSP and acute phosphate nephropathy as well as the development of chronic kidney disease in elderly patients, many of whom had a normal serum creatinine at the time of OSP ingestion. This review summarizes current knowledge about the renal complications of OSP, risk factors for its development, and the pathophysiology of acute and chronic kidney damage in nephrocalcinosis.

Systematic review: the adverse effects of sodium phosphate enema

BACKGROUND

Sodium-phosphate enemas are widely used to treat constipation, and are rarely associated with side effects.

AIM

A systematic review of the literature was conducted to identify the most common adverse effects of sodium-phosphate enemas and associated risk factors.

METHODS

A systematic search was conducted in Internet (MEDLINE), and the Cochrane Library, from January 1957 to March 2007.

RESULTS

A total of 761 references were identified initially, and 39 relevant papers were finally selected. The most common therapeutic indications included constipation (63%). Sixty-eight per cent of the patients having adverse effects had associated conditions, the most common being gastrointestinal motility disorders, cardiological diseases and renal failure. Virtually, all side effects were due to water and electrolyte disturbances. Most patients were under 18 years of age (66%) or older than 65 years (25%). A total of 12 deaths were found.

CONCLUSION

The main side effects caused by sodium phosphate enemas are water and electrolyte disturbances. The main risk factors are extreme age and associated comorbidity.

Renal failure and nephrocalcinosis associated with oral sodium phosphate bowel cleansing: clinical patterns and renal biopsy findings

Acute renal failure (ARF) is rarely reported after bowel preparation with sodium phosphate. We report a patient with mild Crohn disease (in remission), without history of renal disease, and with normal baseline renal function, who developed ARF 14 days after bowel preparation for colonoscopy with oral sodium phosphate. A renal biopsy showed multifocal calcium phosphate deposition in the renal tubules against a background of diffuse chronic tubulointerstitial injury. Review of the literature suggested 2 distinct patterns of ARF in the context of sodium phosphate bowel cleansing. One pattern is characterized by ARF, which develops a few hours or days after sodium phosphate administration, as a component of a systemic syndrome associated with severe hyperphosphatemia and hypocalcemia. Correction of these electrolyte abnormalities was frequently associated with rapid recovery of renal function. The cause of ARF in this context was not clear because the favorable outcome negated the need for renal biopsy. In the second pattern, exemplified by the current patient, ARF was identified incidentally. These patients did not have any features of an acute syndrome immediately after sodium phosphate administration and presented much later (usually weeks) with mild, nonspecific symptoms. At the time of presentation, the serum calcium and phosphate levels were normal. The renal biopsies in each of these patients showed nephrocalcinosis as the possible cause of ARF. The renal failure improved at least partially in most of these patients, but persisted in rare cases.

Severe hyperphosphatemia and hypocalcemia following the rectal administration of a phosphate-containing Fleet pediatric enema

BACKGROUND

Toxicity secondary to rectally administered hypertonic phosphate solution in patients with normal renal function is rarely reported in the literature. We report a case of electrolyte disturbance and seizure secondary to the rectal administration of 2 Fleet pediatric enemas.

CASE REPORT

A 4-year-old white female with spinal muscular atrophy and chronic constipation was brought to the emergency department with complaints of lethargy and difficulty breathing following the administration of 2 Fleet pediatric enemas. In the emergency department, physical examination was significant for a depressed level of consciousness and shallow respirations. A basic metabolic profile was significant for a calcium of 3.3 mg/dL, phosphate of 23 mg/dL, and sodium of 153 mEq/L. Arterial blood gases revealed a pH of 7.24, Pco2 of 38 mm Hg, Po2 of 220 mm Hg. Electrocardiogram revealed a prolonged QT interval of 340 milliseconds with a corrected QT interval of 498 milliseconds. Sixteen hours postexposure, she experienced a generalized seizure unresponsive to multiple doses of lorazepam and responsive only to 100 mg of intravenous calcium chloride. Two days after presentation, the patient experienced complete resolution of symptoms.

CONCLUSION

Osmotically acting hypertonic phosphate enemas can result in severe toxicity if retained. This is true even in patients without predisposing risk factors.

Perioperative management of patients with chronic kidney disease or ESRD

The perioperative management of patients with chronic kidney disease (CKD) or dialysis-dependent end-stage renal disease (ESRD) is complicated by both the underlying renal dysfunction, with associated disturbances of fluid and electrolyte homeostasis and altered drug clearance, and the presence of associated co-morbid conditions, including diabetes mellitus, chronic hypertension and cardiovascular and cerebrovascular disease. The impact of CKD on fluid and electrolyte management, haematological and cardiovascular complications and drug management in the perioperative period are reviewed. Special issues related to the management of haemodialysis and peritoneal dialysis patients in the perioperative period are also reviewed.

Acute hyperphosphatemia caused by sodium phosphate enema in a patient with liver dysfunction and chronic renal failure

We report a case of acute hyperphosphatemia secondary to rectal administration of sodium phosphate and sodium biphosphate (Fleet enema). Parathyroid hormone and calcitonin levels were measured along with phosphate clearance and the tubular reabsorption of phosphate.

[Risk of phosphate enemas in the infant]

BACKGROUND

Hypertonic sodium phosphate enema (Fleet) are available for relief of constipation. They may be responsible for life-threatening electrolyte disturbances (hyperphosphatemia, hypernatremia, hypocalcemia) and severe dehydration.

OBSERVATION

A 14-month-old child with a neonatal repaired Hirschsprung's disease was urgently admitted for apathy. The clinical diagnosis was sepsis from intestinal origin. A few hours before admission, the child had received a pediatric phosphate enema ("Fleet Enema"). The clinical symptoms and the observed electrolyte disturbances were the consequences of the intoxication by the enema.

CONCLUSION

In children with renal insufficiency or bowel dysfunction, phosphate enemas are dangerous. Even in normal children, they should not be used under 2 years of age and only with extreme caution between 2 and 5 years.

Oral Fleet Phospho-Soda laxative-induced hyperphosphatemia and hypocalcemic tetany in an adult: report of a case

PURPOSE

This study was undertaken to report an adverse outcome of the routine use of Fleets Phospho-Soda for bowel cleansing and to review the available literature.

METHOD

Report of a case and review of the literature is presented.

RESULT

Administration of Fleets Phospho-Soda for bowel preparation in an adult resulted in hyperphosphatemia and hypocalcemic tetany. Review of the literature shows this to be the first such report. Further evaluation suggests a role for partial bowel obstruction and renal failure in this complication.

CONCLUSION

Although Fleet Phospho-Soda solution continues to be a safe bowel preparation, caution should be used in adults with bowel obstruction and renal failure.

Severe hyperphosphatemia following phosphate administration for bowel preparation in patients with renal failure: two cases and a review of the literature

Two cases of severe hyperphosphatemia following phosphate bowel preparation are described and a review of the literature is presented. Impairment of renal function appears to be a risk factor in those patients without primary bowel pathology. One of our patients died, and the mortality rate combining our cases with all other reported cases is 33%. Repeated doses of phosphate bowel preparations/purgatives can be dangerous in patients with renal impairment.

Hyperphosphatemic hypocalcemic coma caused by hypertonic sodium phosphate (fleet) enema intoxication

We describe an elderly woman with a deep hyperphosphatemic hypocalcemic coma, hypernatremia, hypokalemia, metabolic acidosis, pancytopenia and respiratory and circulatory failure secondary to phosphate intoxication following the overdose administration of hypertonic sodium phosphate enema. The causes of increased colonic retention and absorption and decreased renal excretion are discussed. We recommend the use of the safer and less toxic cathartic medications or at least a very cautions use of such enemas in anyone with renal failure.

Effect of oral sodium phosphate colon preparation on serum electrolytes in patients with normal serum creatinine

BACKGROUND

Oral sodium phosphate is commonly used for colon preparation prior to colonoscopy. Several studies have demonstrated significant changes in serum electrolytes after sodium phosphate preparation, but failed to stratify patients with regard to renal function. The purpose of this study was to determine if electrolyte alterations are observed after sodium phosphate in patients with normal levels of serum creatinine.

METHODS

Thirty-two patients scheduled for elective colonoscopy who had a serum creatinine level of less than 1.5 mg/dL were enrolled. All patients had a panel of laboratory studies prior to and immediately after receiving oral sodium phosphate colon preparation.

RESULTS

Significant increases in serum phosphate and sodium and decreases in serum calcium and potassium were observed. Twenty-eight percent of patients had serum phosphate levels greater than 8.0 mg/dL, and 6% of patients had serum calcium levels less than 8.0 mg/dL after sodium phosphate colon preparation. There were no clinically apparent adverse events.

CONCLUSIONS

Significant changes in serum electrolyte levels occur after sodium phosphate colon preparation in patients with normal serum creatinine levels. Sodium phosphate could exacerbate pre-existing hypocalcemia or hypokalemia in patients with apparently normal renal function. Therefore, it may be prudent to evaluate serum electrolytes prior to administration of sodium phosphate.

Biochemical effects of oral sodium phosphate

Our objective was to monitor serum and urine biochemical changes after oral sodium phosphate cleansing in a prospectively designed study. The study subjects were seven healthy, asymptomatic adults. Sodium phosphate 45 ml diluted in 45 ml water was given orally at baseline and 12 hr later. Calcium, ionized calcium, phosphorus, sodium, potassium, creatinine, and PTH were analyzed at 2, 4, 6, 9, 12, 14, 16, 18, 21 and 24 hr after the first challenge. Urinary calcium, phosphorus, sodium, potassium, and cyclic AMP were analyzed at baseline and every 2 hr after oral sodium phosphate. Blood pressure, pulse, and respiratory rate were recorded every 2 hr and symptom questionnaires using visual analog scales were completed. A marked rise in phosphorus (peak range 3.6-12.4 mg/dl, P < 0.001) and falls in calcium (P < 0.001) and ionized calcium (P < 0.001) were seen. Rises seen in PTH and urinary cAMP confirmed the physiologic significance of the biochemical effect. There were no significant changes in other serum and urine laboratory or clinical assessments. Reported significant symptoms included bloating, cramps, abdominal pain, and nausea. Significant hypocalcemia and hyperphosphatemia after oral sodium phosphate raises concern about its use in normal individuals. Oral sodium phosphate should not be administered in patients with cardiopulmonary, renal, or hepatic disease.

Severe hyperphosphatemia induced by a phosphate-containing oral laxative

OBJECTIVE

To describe a case of severe hyperphosphatemia following unintentional overdosage with an oral phosphate laxative, and raise attention to the risk of using such medications in the elderly.

CASE SUMMARY

An 84-year-old white woman was admitted with confusion 8 hours after inadvertently ingesting 12 fluid ounces of Fleet Phospho-Soda (instead of the prescribed 1 1/2 fluid ounces) prior to a colonoscopy. Her serum phosphate and ionized calcium concentrations were 10.3 mmol/L and 0.56 mmol/L, respectively. She was treated conservatively with oral phosphate binders and made an uneventful recovery.

DISCUSSION

Several previous reports have described hyperphosphatemia in association with phosphate laxatives, especially in patients with renal or colonic disease. Our case again presents two important issues in the use of phosphate laxatives by the elderly: (1) the frequently overlooked underlying renal insufficiency in which, despite "normal" serum creatinine values, renal phosphate handling may be impaired; and (2) the potential for drug misuse and poor compliance in the elderly.

CONCLUSIONS

Caution should be taken with the use of phosphate laxatives in the elderly in the face of potentially serious metabolic abnormalities that may be generated.

Bowel preparation for colonoscopy: a randomized prospective trail comparing sodium phosphate and polyethylene glycol in a predominantly elderly population

Many patients find polyethylene glycol-based preparations (PEG) difficult to take because of the large volume of fluid they are required to consume. One hundred and sixteen predominantly elderly patients were randomized to receive either sodium phosphate (n = 61) or PEG (n = 55) bowel preparations before colonoscopy. Patients with a history of symptomatic ischaemic heart disease or cerebrovascular disease in the preceding 6 months, severe liver disease or heart failure, or serum creatinine above 200 micrograms/L were excluded from the study. Each patient filled in a questionnaire about the bowel preparation prior to the procedure. The colonoscopists, who were not aware which preparation had been used, were asked to complete a questionnaire about the quality of the bowel preparation after the procedure. The patients found the sodium phosphate preparation slightly more tolerable than PEG. Side effects were slightly more common with sodium phosphate. Neither difference was statistically significant. However, 91% of patients who had previously had PEG found sodium phosphate easier to take. Approximately 25% of patients in each group experienced at least one episode of incontinence. The colonoscopists found no difference in the overall quality of the bowel preparation. The amount of fluid in the colon was greater in patients prepared with PEG. As expected, patients taking sodium phosphate developed hyperphosphataemia (mean phosphate level before colonoscopy 1.56 mmol/L, normal 0.8 -1.3). They also had a lower mean serum potassium level (3.8 mmol/L) than the PEG group (4.2 mmol/L). However, there were no clinically significant consequences. Sodium phosphate was a safe and effective bowel preparation for colonoscopy in this carefully selected group of patients. It was preferred by patients who had previously had PEG. Many elderly patients were found to develop faecal incontinence, irrespective of the type of bowel preparation used.

Oral sodium phosphate versus sulfate-free polyethylene glycol electrolyte lavage solution in outpatient preparation for colonoscopy: a prospective comparison

BACKGROUND

Biochemical abnormalities induced by oral sodium phosphate and the risk of cardiac arrhythmias as potential sequelae have yet to be investigated.

METHODS

We studied 98 outpatients scheduled to undergo diagnostic colonoscopy and prospectively randomized them to receive oral sodium phosphate or sulfate-free polyethylene glycol electrolyte lavage solution (SF-PEG-ELS) as recommended by the manufacturers.

RESULTS

Forty-nine patients received sodium phosphate and 49 received SF-PEG-ELS. There was no significant difference in tolerance or quality of preparation as judged by blinded endoscopists. Significant changes in serum sodium, potassium, chloride, calcium, ionized calcium, and inorganic phosphorus levels were noted following sodium phosphate preparation when compared to values before preparation. A significantly greater number of patients who received sodium phosphate preparation had serum potassium and ionized calcium levels that fell into the abnormal range. Ambulatory electrocardiogram monitors placed 24 hours before the preparation and removed after colonoscopy showed no increase in ventricular premature contractions or other serious arrhythmias in either group during preparation or colonoscopy.

CONCLUSIONS

(1) Sodium phosphate and SF-PEG-ELS are equally well tolerated and effective in preparation for outpatient colonoscopy, and (2) sodium phosphate preparation at the recommended dose causes significant alterations in serum sodium, potassium, chloride, calcium, ionized calcium, and phosphorus levels.

Review of the literature: severe hyperphosphatemia

A patient with a markedly elevated serum phosphorus level (23.9 mg/dL) is described, followed by a brief review of severe hyperphosphatemia. Elevated serum phosphorus levels may be artifactual or true. True hyperphosphatemia is usefully subdivided according to (a) whether phosphorus is added to the extracellular fluid from a variety of exogenous or endogenous sources, or (b) whether the urinary excretion of phosphorus is reduced from either decreased glomerular filtration or increased tubular reabsorption. Severe hyperphosphatemia, defined herein as levels of 14 mg/dL or higher, is almost invariably multifactorial--usually resulting from addition of phosphorus to the extracellular fluid together with decreased phosphorus excretion. The hyperphosphatemia of the patient described herein appeared to result from a combination of dietary phosphorus supplementation, acute renal failure, acute pancreatitis, and ischemic bowel disease, complicated by lactic acidosis.

Serum electrolyte, mineral, and blood pH changes after phosphate enema, water enema, and electrolyte lavage solution enema for flexible sigmoidoscopy

Hypertonic sodium phosphate (Fleet) enema is a commonly used preparation for fiberoptic flexible sigmoidoscopy. Unfortunately, Fleet has been associated with complications in children and adults. The purpose of this study was to compare the serum electrolytes, mineral, and blood pH changes before and after the administration of Fleet with water and polyethylene glycol electrolyte lavage solution (Golytely) as enemas in an adult population undergoing flexible sigmoidoscopy. Sixty-six patients were randomized in a double-blind fashion to receive two enemas of either Fleet (N = 22), water (N = 20), or Golytely (N = 24). The cleansing ability was graded from 1 to 4 (1 = poor, 4 = excellent). The Fleet had significantly better optimal cleansing efficacy compared with water (p < 0.05) but not to Golytely (p > 0.05). There was a significant increase in the serum phosphorus in the Fleet group compared with water (p < 0.001) or Golytely (p < 0.001). However, absolute serum phosphorus values after Fleet enema always remained within normal range in all but one patient. The changes in other electrolytes, minerals, and venous pH were insignificant.

Severe hyperphosphatemia associated with hemorrhagic shock

Hyperphosphatemia is an electrolyte abnormality that most frequently results from renal insufficiency and the attendant inability to excrete phosphorus (PO4) efficiently. A case is presented in which a young man with hemorrhagic shock developed severe hyperphosphatemia in the absence of renal failure. This is the first such case documented to the authors' knowledge. The prompt correction of the primary cause (ie, hypoperfusion and acidosis) resulted in a rapid return of PO4 levels to normal. This was probably related to the intracellular shift of PO4. Physicians should be aware of this electrolyte disturbance because it is not a well-recognized complication and because, in most cases, proper treatment of shock will also correct the elevated PO4.

Hyperphosphataemia and hypocalcaemia induced by hypertonic phosphate enema--an experimental study and review of the literature

1. The study objective was to determine the hyperphosphataemic and hypocalcaemic effect of hypertonic phosphate enema. The study was conducted in a department of Internal Medicine at a University Medical Center. 2. Fourteen patients were studied. Patients' mean age (+/- s.d.) was 78.5 +/- 9 years. The creatinine clearance was 48.2 +/- 17.4 ml min-1 (mean +/- s.d.). 3. 500 ml (approx. 7 ml kg-1) of Fleet enema (FE - Na2HPO4.7H2O 224 mmol l-1 and NaH2PO4.H2O 1160 mmol l-1) were administered to each patient. Blood was drawn before FE administration and 1/2, 1, 3, 5, 12 and 24 h thereafter. Serum was analysed for levels of inorganic phosphorus and for calcium. 4. The serum inorganic phosphorus level rose from 1.01 +/- 0.3 mmol l-1 to 1.4 +/- 0.5 mmol l-1 (P = 0.001) 1 h after FE was administered. Serum calcium decreased from 2.32 +/- 0.12 mmol l-1 to 2.12 +/- 0.1 mmol l-1 (P less than 0.001) 12 h after FE was administered. 5. We conclude that FE carries a potential risk for acutely ill elderly patients. To avoid untoward effects due to hyperphosphataemia and hypocalcaemia, the phosphate load must be adjusted to the patient's renal function, i.e. enema volume is to be lowered when phosphate concentration is high, so that if renal function is compromised the amount of phosphate absorbed does not exceed renal excretion capacity.

Iatrogenic hypocalcemic tetany

The treatment of a patient with hypocalcemic tetany secondary to sodium phosphate enemas is reported. The patient presented with a serum calcium level of 5.2 mg/dL and a phosphate level of 17.5 mg/dL. Physical manifestations included tetanic contraction of the muscles of the legs and arms. There was rapid symptomatic resolution with IV calcium. The electrolyte imbalance normalized over the next two days with oral calcium supplementation.

Comparative studies on the usefulness of phosphate versus glycerin enema in preparation for colon examinations

Fifty of 100 persons who had undergone health screening received phosphate enema while the other 50 received glycerin enema prior to proctoscopy and barium enema, and their usefulness for preparation for colon examination was compared by a double-blind test. There was no significant difference in the degree of colonic cleansing achieved by proctoscopy and barium enema. In the subjects who received phosphate enema, the incidence of abdominal pain was less than that in those who received glycerin enema, while the effect of phosphate enema on defecation appeared later than that of glycerin enema, indicating prolonged stool retention in the subjects given phosphate enema. To study the safety of the two enemas, either phosphate enema, glycerin enema or physiological saline solution as a control was administered at 0.35 ml/animal in the rectum by 4-h closure of the anus in 10 male 7-week-old Wistar rats, and the rectal mucosa was observed for irritation macroscopically and histopathologically. Glycerin enema produced less irritation than phosphate enema diffusely in the entire area of the rectum, while phosphate enema produced more local irritation at the end of the rectum than glycerin enema. The differences in the extent of irritation and injury between phosphate and glycerin enemas were considered to be derived from differences in the pharmacologic actions of these drugs. If the extent of injury were included in the extent of irritation, the difference in irritation between phosphate and glycerin enemas would not be significant. As described above, no specific difference seem to exist in the usefulness of phosphate and glycerin enemas as preparation for colon examination.

Severe hyperphosphatemia, hypocalcemia, acidosis, and shock in a 5-month-old child following the administration of an adult Fleet enema

We report the case of a 5-month-old girl who was given an adult Fleet enema by her mother because of her concern that the baby was constipated. Within minutes the child became extremely ill. She developed shock, hyperphosphatemia, hypocalcemia, and acidosis. This case is presented to demonstrate that life-threatening events may result after the injudicious use of enemas in children.