Sodium phosphate is superior to polyethylene glycol in bowel cleansing and shortens the time it takes to visualize colon mucosa

Split-Dose Preparations Are Superior to Day-Before Bowel Cleansing Regimens: A Meta-analysis

BACKGROUND & AIMS

There are different regimens of preparing the colon for colonoscopy, including polyethylene glycol (PEG), sodium phosphate, picosulfate, or oral sulfate solutions. We performed a meta-analysis to determine the efficacy of split-dose vs other colon preparation regimens, the optimal products for use, and the most effective preparation volumes.

METHODS

We performed systematic searches of MEDLINE, EMBASE, Scopus, CENTRAL, and ISI Web of knowledge databases, from January 1980 to March 2014, for published results from randomized trials that assessed split-dose regimens vs day-before colonoscopy preparation. We excluded studies that included pediatric or hospitalized patients, or patients with inflammatory bowel disease. The primary outcome was efficacy of bowel cleansing. Secondary outcomes included side effects or complications, outcomes of procedures, patients' willingness to repeat the procedure, and the amount of time required for patients to resume daily activities.

RESULTS

We identified 47 trials that fulfilled our inclusion criteria (n = 13,487 patients). Split-dose preparations provided significantly better colon cleansing than day-before preparations (odds ratio [OR], 2.51; 95% confidence interval, 1.86-3.39), as well as day-before preparations with PEG (OR, 2.60; 95% confidence interval, 1.46-4.63), sodium phosphate (OR, 9.34; 95% confidence interval, 2.12-41.11), or picosulfate (OR, 3.54; 95% confidence interval, 1.95-6.45). PEG split-dose preparations of 3 L or more yielded greater bowel cleanliness than lower-volume split-dose regimens (OR, 1.89; 95% confidence interval, 1.01-3.46), but only in intention-to-treat analysis. A higher proportion of patients were willing to repeat split-dose vs day-before cleansing (OR, 1.90; 95% confidence interval, 1.05-3.46), and low-volume split-dose preparations vs high-volume split-dose preparation (OR, 4.95; 95% confidence interval, 2.21-11.10). There were no differences between preparations in other secondary outcome measures. However, there was variation among studies in definitions and main and secondary outcomes.

CONCLUSIONS

Based on meta-analysis, split-dose regimens increase the quality of colon cleansing and are preferred by patients compared with day-before preparations. Additional research is required to evaluate oral sulfate solution-based and PEG low-volume regimens further.

Bowel preparations as quality indicators for colonoscopy

Colonoscopy is the principal investigative procedure for colorectal neoplasms because it can detect and remove most precancerous lesions. The effectiveness of colonoscopy depends on the quality of the examination. Bowel preparation is an essential part of high-quality colonoscopies because only an optimal colonic cleansing allows the colonoscopist to clearly view the entire colonic mucosa and to identify any polyps or other lesions. Suboptimal bowel preparation not only prolongs the overall procedure time, decreases the cecal intubation rate, and increases the costs associated with colonoscopy but also increases the risk of missing polyps or adenomas during the colonoscopy. Therefore, a repeat examination or a shorter colonoscopy follow-up interval may be suitable strategies for a patient with suboptimal bowel preparation.

A pilot study of endoluminal US for stool liquefaction

BACKGROUND

There is a need to cleanse patients who are poorly prepared for colonoscopy safely and efficiently during the procedure to minimize rescheduling. US is already being used in catheter-based intravascular thrombolysis, and time-reversal acoustic (TRA) has been explored in assisting drug delivery to the brain.

OBJECTIVE

To explore the efficacy and safety of a miniaturized endoluminal US device in stool dissolution as a means to salvage poor bowel preparation.

DESIGN

Proof of concept experimental study.

SETTINGS

Animal laboratory.

INTERVENTIONS

Low-frequency US and TRAs.

MAIN OUTCOME MEASUREMENTS

Feasibility, efficacy, and safety of US to liquefy stools ex vivo.

RESULTS

Depending on parameters, such as pulse rate, acoustic intensity, and duration, increases in liquefaction speeds by a factor of 50 and 100 times were obtained. There was a significant difference in weight change between the 20-kHz-treated sample compared with controls (P ≤ .0001). There was no difference in sloughing of mucosa and mechanical injury among the US, water spray, and control groups.

LIMITATIONS

Animal model.

CONCLUSION

Endoluminal US can liquefy stools at acoustic exposure levels that do not damage ex vivo colonic mucosa. Endoluminal US should be able to dissolve stools more rapidly than water spray alone, thereby optimizing colonoscopic evaluation in vivo.

A prospective study of bowel preparation for colonoscopy with polyethylene glycol-electrolyte solution versus sodium phosphate in Lynch syndrome: a randomized trial

Lynch gene carriers undergo regular surveillance colonoscopies. Polyethylene glycol-electrolyte solution (PEG) is routinely prescribed for bowel cleansing, but often poorly tolerated by patients. Sodium phosphate (NaP) may be an alternative. Prospective and random comparison of bowel preparation with PEG and NaP on colon cleansing and patients' acceptance. Patients, who previously underwent a colonoscopy, were invited to participate and randomly assigned to either PEG or NaP. They were asked to fill in a questionnaire about preparation tolerability and future preferences. The endoscopist filled out a report about the quality of colon cleansing. 125 Patients were included in the study. Nine (7%) were excluded because of missing data. The remaining 116 patients (53 PEG and 63 NaP) were included in the analysis. Baseline characteristics did not differ between groups. Before colonoscopy 20 (38%) patients using PEG experienced the preparation almost intolerable, in contrast to 7(11%) of those using NaP (P = 0.001). Eleven patients in the PEG group and 48 in the NaP group would prefer NaP in the future. The colonoscopy was poorly tolerated in 17% of the individuals in both groups (P = 0.963). The endoscopist observed a more than 75% clean colon in 83% of patients on PEG and in 71% of patients on NaP (P = 0.076), however the coecum (P = 0.025) and ascending colon was cleaner after PEG. Lynch patients tolerated NaP better and preferred this formula for future bowel preparation. Colon cleansing was suboptimal with both treatments with a tendency towards a cleaner proximal colon with PEG.

Meta-analysis: randomized controlled trials of 4-L polyethylene glycol and sodium phosphate solution as bowel preparation for colonoscopy

BACKGROUND

Randomized controlled trials (RCTs) comparing polyethylene glycol (PEG) with sodium phosphate (NaP) are inconsistent.

AIM

To compare the efficacy of and tolerance to PEG vs. NaP for bowel preparation.

METHODS

We used MEDLINE and EMBASE to identify English-language RCTs published between 1990 and 2008 comparing 4-L PEG with two 45 mL doses of NaP in adults undergoing elective colonoscopy. We calculated the pooled odds ratios (ORs) for preparation quality and proportion of subjects completing the preparation.

RESULTS

From 18 trials (n = 2792), subjects receiving NaP were more likely to have an excellent or good quality preparation than those receiving PEG (82% vs. 77%; OR = 1.43; 95% CI, 1.01-2.00). Among a subgroup of 10 trials in which prep quality was reported in greater detail, there were no differences in the proportions of excellent, good, fair or poor preparation quality. Among nine trials that assessed preparation completion rates, patients receiving NaP were more likely to complete the preparation than patients receiving 4-L PEG (3.9% vs. 9.8% respectively did not complete the preparation; OR = 0.40; CI, 0.17-0.88).

CONCLUSION

Among 18 head-to-head RCTs of NaP vs. 4-L PEG, NaP was more likely to be completed and to result in an excellent or good quality preparation.

A prospective assessment of renal impairment after preparation for colonoscopy: oral sodium phosphate appears to be safe in well-hydrated subjects with normal renal status

BACKGROUND

The outcome of colonoscopy is highly dependent upon the quality of bowel cleansing prior to the procedure. Oral sodium phosphate solutions (OSPS) or preparations containing polyethylene glycol (PEG) are generally employed. However, the safety of administering OSPS prior to colonoscopy has been questioned because of the potential for renal failure.

AIM

To compare rates of renal failure after OSPS and PEG in a randomized, prospective trial and to assess the quality of colonoscopy after these two bowel preparations.

METHODS

Subjects with eGFR >or= 60 ml/min/1.73 m(2) and expressed willingness to adhere to hydration recommendations were randomized to OSPS or PEG solutions. Renal function was assessed 1 week prior to, immediately prior to, and 1 week after colonoscopy.

RESULTS

No subject had acute kidney failure after OSPS or PEG. OSPS was associated with significant increases in the serum phosphate and sodium levels and significant decreases in the calcium and potassium levels. These values returned to normal limits in all subjects by 1 week after colonoscopy. The quality of colonic cleansing was superior after OSPS than after PEG (Ottawa score 2.5 +/- 2.2 vs. 3.5 +/- 2.3, respectively, P < 0.05). The detection of one or more adenomatous polyps was higher after OSPS than after PEG.

CONCLUSIONS

Renal failure was not detected after the use of OSPS for colonoscopy preparation in subjects with recently documented normal renal function who were able to consume the required amounts of water after each dose. However, based on the number of subjects studied, the theoretical risk of this complication is still between 0 and 6.3%. Thus, it is appreciated that only a very large prospective trial would have yielded a more accurate estimate of the likelihood of renal compromise after OSPS. Despite this caveat, OSPS has advantages over PEG in terms of the adequacy of colonic visualization and the number of polyps detected.

Severe hyperphosphatemia and symptomatic hypocalcemia after bowel cleansing with oral sodium phosphate solution in a patient with postoperative hypoparathyroidism

Oral sodium phosphate (NaP) is increasingly being used for bowel preparation. There are several reports of significant serum electrolyte changes after the administration of oral NaP solution in renal failure. We report a case of postoperative hypoparathyroidism who developed severe hyperphosphatemia and associated hypocalcemia after bowel preparation with oral NaP. A 39-year old woman was admitted to the hospital because of multiple bone fractures. The diagnosis of primary hyperparathyroidism was confirmed. Further assays suggested Cushing’s disease and MRI disclosed a pituitary microadenoma. Considering the diagnostic suspect of multiple endocrine neoplasia type 1, computed tomography of abdomen was performed, showing a mass in the right adrenal. The patient underwent transsphenoidal surgery and then total parathyroidectomy. Despite total removal of the microadenoma by transsphenoidal surgery, there was no suppression in serum cortisol levels. So, an operation was scheduled for the adrenal tumor. The patient was administered 45 mL oral NaP solution for bowel cleansing before the surgery. Although her calcium and phosphorus levels were normal before NaP administration, four hours later she developed respiratory distress and tetany. Laboratory studies revealed severe hyperphosphatemia and hypocalcemia. We conclude that the use of NaP for bowel preparation should be avoided in patients with hypoparathyroidism.

Efficacy of prepackaged, low residual test meals with 4L polyethylene glycol versus a clear liquid diet with 4L polyethylene glycol bowel preparation: a randomized trial

BACKGROUND AND STUDY AIMS

A prepackaged low residue one-day diet (breakfast, lunch and dinner) has been recently developed to improve patient tolerance for bowel preparation prior to colonoscopy. The aims of this study were to evaluate the efficacy and tolerability of bowel preparation protocols based on a low residue diet and 4L polyethylene glycol (PEG) solution, and to compare these new options with the traditional liquid diet and the PEG 4L lavage.

METHODS

A total of 214 patients (mean age: 54.1 years; 120 male, 94 female) from four university hospitals were included in the analysis. Patients were randomized to receive a clear liquid diet and the PEG 4L regimen (106 patients) or the low residue test meals and the PEG 4L regimen (TM-PEG 4L, 108 patients). The colon cleansing efficacy of the different preparations was rated using the Ottawa bowel preparation scale.

RESULTS

No significant differences were observed between the treatment groups according to the Ottawa cleansing scale findings (PEG 4L: 2.97 vs TM-PEG 4L: 2.46, P = 0.063). The overall tolerability was higher in the TM-PEG 4L group than in the PEG 4L group (P = 0.036). No difference was found when the two groups were compared with regard to adverse events (P = 0.599).

CONCLUSIONS

A prepackaged low residue one-day diet provided cleansing efficacy similar to that of a clear liquid diet and offered the benefit of improved tolerability compared to the conventional PEG 4L regimen.

Colon cleansing before colonoscopy: does oral sodium phosphate solution still make sense?

Oral sodium phosphate (NaP) solution has been withdrawn from the market in the United States but remains available for over-the-counter purchase for bowel preparation for colonoscopy in Canada. The present review summarizes recent data regarding the renal toxicity of oral NaP as well as its efficacy and tolerability relative to other preparations. Given the availability of effective alternatives to NaP solution, its use for colonoscopy preparation in Canada should be limited. Candidate patients for oral NaP solution should be assessed for eligibility and preparation instructions should adhere to the current recommendations for maximizing the safety of oral NaP.

Oral sodium phosphates solution versus polyethylene glycol for colon cleansing prior to radiological assessment

A clean bowel environment is essential prior to radiological assessment of the colon. The objectives were to determine patient compliance and acceptability, physician satisfaction, overall clinical effectiveness and tolerability with the use of oral sodium phosphates (Fosfosoda) and polyethylene glycol solutions as bowel cleansing agents in a relatively large cohort of Spanish patients requiring radiologic examination of the colon. This was an observational survey involving 592 patients (> or =18 years and approximately 60% women) who received Fosfosoda or polyethylene glycol solutions according to data sheet instructions. Parameters measured included mucosal cleansing (presence of solid residues), patient acceptability (including any adverse effects to treatment) and compliance with the treatment regimen, and physician-rated satisfaction with the procedure. The date from the study demonstrated that Fosfosoda and polyethylene glycol solutions were found to be equally well tolerated in this study, although patients receiving Fosfosoda found it easier to complete the treatment regimen. Fosfosoda was significantly superior to polyethylene glycol solutions with regards to mucosal cleansing with 52% achieving an 'excellent' result compared with only 36% of the polyethylene glycol group (relative risk:1.43; 95% confidence interval: 1.12-1.82). Physician-rated assessment of the bowel cleansing procedure also significantly favored Fosfosoda (p = 0.014). In conclusion, while Fosfosoda and polyethylene glycol solutions were equally well tolerated when given to patients prior to radiologic examination of the colon, Fosfosoda was shown to be significantly more effective in terms of bowel cleansing. Based upon the available evidence this could provide significant cost benefit for Fosfosoda.

Which is the optimal bowel preparation for colonoscopy - a meta-analysis

OBJECTIVE

To assess which bowel preparation agent is most effective.

METHODS

A search of randomized trials between January 1990 and July 2005 was obtained, using MEDLINE and PubMed databases, and the Cochrane Central Register of Controlled Trials. Meta-analysis was performed using the Forest plot review.

RESULTS

Sodium phosphate (NaP) was more effective in bowel cleansing than polyethylene glycol (PEG) - odds ratio 0.75 (95%CI: 0.65-0.88; P = 0.0004); and sodium picosulphate (SPS) - odds ratio 0.52 (95%CI: 0.34-0.81; P = 0.004). PEG and SPS were comparable in bowel cleansing ability, odds ratio 1.69 (95%CI: 0.92-3.13; P = 0.09). NaP was more easily completed by patients compared to PEG, odds ratio 0.16 (95%CI: 0.09-0.29; P < 0.00001). More patients were able to complete SPS than PEG, but this was not statistically significant - odds ratio 0.56 (95%CI: 0.28-1.13; P = 0.11). NaP and PEG were comparable in terms of adverse events, odds ratio 0.98 (95%CI: 0.82-1.17; P = 0.81), although NaP resulted in more asymptomatic hypokalaemia and hyperphosphataemia. NaP and SPS appeared to have similar incidence of adverse events. PEG resulted in more adverse events than SPS, odds ratio 3.82 (95%CI: 1.60-9.15; P = 0.003).

CONCLUSIONS

NaP was more effective in bowel cleansing than PEG or SPS and was comparable in terms of adverse events. Patients have more difficulty completing PEG than NaP and SPS. Biochemical changes associated with a small-volume preparation like NaP, albeit largely asymptomatic, mandate caution in patients with cardiovascular or renal impairment.

A prospective randomized blinded comparison of sodium phosphate and polyethylene glycol-electrolyte solution for safe bowel cleansing

BACKGROUND

Polyethylene glycol-electrolyte solution (PEG-ELS) is routinely prescribed for bowel cleansing. Sodium phosphate (NaP) may be an effective but potentially hazardous alternative.

AIM

To investigate the safety of prescription of either agent, without being informed of the patient's medical history.

METHODS

One hundred consecutive patients were randomly allocated to PEG-ELS or NaP. Prior to and after the bowel cleansing, blood was sampled for renal function and electrolytes. Patients answered questionnaires about complaints and ease of intake, and endoscopists rated the quality of bowel preparation.

RESULTS

Eleven patients were identified with a theoretical contraindication for NaP, of whom nine should have been discovered by taking a detailed clinical history. Actually, six of them received NaP with a doubling of serum phosphate levels or hypokalaemia in four. In subjects without a contraindication to the use of NaP, hyperphosphataemia developed in 39% and hypocalcaemia in 5%. Patients tolerated NaP better and completed the preparation more often. Endoscopists rated the quality of bowel preparation equivalent, except for a better cleansed ascending colon with PEG-ELS.

CONCLUSIONS

The 11% potentially hazardous allocation to NaP and the 39% incidence of hyperphosphataemia with NaP do not justify an 'over-the-counter' prescription. Taking a detailed history and, when in doubt, using PEG-ELS will safeguard against inappropriate administration of NaP.