Impact of water exchange colonoscopy on serum sodium and potassium levels: an observational study.

BACKGROUND: Concerns over the hypothetical adverse effects of water absorption and the disturbance of serum sodium and potassium levels prompted a quality assurance evaluation of water exchange (WE) colonoscopy. AIM: The purpose of this study was to evaluate the balance of water infused and suctioned in WE colonoscopy, and to quantify the acute impact on serum levels of sodium and potassium. METHODS: Prospectively collected quality monitoring data of patients undergoing screening and surveillance colonoscopy at the Sacramento Veterans Affairs Medical Center were analyzed. Measurements were made of volume infused and suctioned during, and blood samples drawn 10 min before the start of and 10 min after completion of WE colonoscopy. Outcome measures included volume of water infused and suctioned, and serum levels of sodium and potassium. RESULTS: A total of 140 patients (134M:6F), mean age of 59, underwent WE colonoscopy. Mean total volume of water infused was 1,839 mL. A negative balance of an average of 22 mL was documented. The mean (standard deviation) values (in meq/L) of serum levels of sodium 139.33 (2.27) and 139.28 (2.32), and potassium 3.86 (0.36) and 3.91 (0.39), before and after colonoscopy, respectively, showed no significant change. CONCLUSION: The WE method allowed most of the water infused during colonoscopy to be recovered by suction at the completion of colonoscopy. Serum sodium and potassium levels did not change significantly within 10 min after completion. The WE method appears to be safe with minimal water retention and is devoid of acute fluctuations in serum levels of sodium and potassium.

Options of sedation or no sedation for colonoscopy - the perspective of the GI nurses and technicians.

OBJECTIVE: Nurses (patient-advocates) and technicians (member of colonoscopy team) collected data on patient discomfort and evaluated various options of sedation or no sedation associated with the air and water methods for performing colonoscopy. METHOD: Veterans participated in studies comparing air and water method colonoscopy. Options using minimal or on demand sedation were evaluated. RESULTS: Compared with the air method, the water method was associated with significantly lower pain scores, higher patient satisfaction ratings and shorter recovery times. On demand sedation was comparable to routine sedation when the water method was used. Patients prefer to be in control of when their medications would be administered during colonoscopy. CONCLUSION: Evaluations by nurses (patient advocates) and technicians (member of colonoscopy team) with experience in assisting patients undergoing colonoscopy using the various options indicate the following. In settings without access to sedation, the water method is ideal for unsedated colonoscopy or extended flexible sigmoidoscopy for screening. Otherwise, the water method and on demand sedation is the most credible combination of options for patient care.

A randomized, controlled trial to confirm the beneficial effects of the water method on U.S. veterans undergoing colonoscopy with the option of on-demand sedation.

BACKGROUND: Sedation for colonoscopy discomfort imposes a recovery-time burden on patients. The water method permitted 52% of patients accepting on-demand sedation to complete colonoscopy without sedation. On-site and at-home recovery times were not reported. OBJECTIVE: To confirm the beneficial effect of the water method and document the patient recovery-time burden. DESIGN: Randomized, controlled trial, with single-blinded, intent-to-treat analysis. SETTING: Veterans Affairs outpatient endoscopy unit. PATIENTS: This study involved veterans accepting on-demand sedation for screening and surveillance colonoscopy. INTERVENTION: Air versus water method for colonoscope insertion. MAIN OUTCOME MEASUREMENTS: Proportion of patients completing colonoscopy without sedation, cecal intubation rate, medication requirement, maximum discomfort (0 = none, 10 = severe), procedure-related and patient-related outcomes. RESULTS: One hundred veterans were randomized to the air (n = 50) or water (n = 50) method. The proportions of patients who could complete colonoscopy without sedation in the water group (78%) and the air group (54%) were significantly different (P = .011, Fisher exact test), but the cecal intubation rate was similar (100% in both groups). Secondary analysis (data as Mean [SD]) shows that the water method produced a reduction in medication requirement: fentanyl, 12.5 (26.8) µg versus 24.0 (30.7) µg; midazolam, 0.5 (1.1) mg versus 0.94 (1.20) mg; maximum discomfort, 2.3 (1.7) versus 4.9 (2.0); recovery time on site, 8.4 (6.8) versus 12.3 (9.4) minutes; and recovery time at home, 4.5 (9.2) versus 10.9 (14.0) hours (P = .049; P = .06; P = .0012; P = .0199; and P = .0048, respectively, t test). LIMITATIONS: Single Veterans Affairs site, predominantly male population, unblinded examiners. CONCLUSION: This randomized, controlled trial confirms the reported beneficial effects of the water method. The combination of the water method with on-demand sedation minimizes the patient recovery-time burden. ( CLINICAL TRIAL REGISTRATION NUMBER: NCT00920751.).

A randomized, controlled comparison of warm water infusion in lieu of air insufflation versus air insufflation for aiding colonoscopy insertion in sedated patients undergoing colorectal cancer screening and surveillance.

BACKGROUND: Pilot studies using a novel water method to perform screening colonoscopy allowed patients to complete colonoscopy without sedation medications and also significantly increased the cecal intubation success rate. OBJECTIVE: To perform a randomized, controlled trial comparing air insufflation (conventional method) and water infusion in lieu of air insufflation (study method) colonoscopy in minimally sedated patients. HYPOTHESIS: Compared with the conventional method, patients examined by the study method had lower pain scores and required less medication but had a similar cecal intubation rate and willingness to undergo colonoscopy in the future. SETTING: Outpatient colonoscopy in a single Veterans Affairs hospital. METHODS: After informed consent and standard bowel preparation, patients received premedications administered as 0.5-increments of fentanyl (25 microg) and 0.5-increments of Versed (midazolam) (1 mg) plus 50 mg of diphenhydramine. The conventional and the study methods for colonoscopy were implemented as previously described. Additional pain medications were administered at the patients' request. MAIN OUTCOME MEASUREMENTS: Increments of medications, pain scores, cecal intubation, and willingness to repeat colonoscopy. RESULTS: Increments of medications used before reaching the cecum (1.6 +/- 0.2 vs 2.4 +/- 0.2, P < .0027), total increments used (1.8 +/- 0.2 vs 2.5 +/- 0.2, P < .014), and the maximum pain scores (1.3 +/- 0.3 vs 4.1 +/- 0.6, P < .0002) were significantly lower with the water method. Cecal intubation rate (100%) and willingness to undergo a repeat colonoscopy (96%) were similar. LIMITATIONS: Single Veterans Affairs hospital, older male population. CONCLUSION: Water infusion in lieu of air insufflation is superior to air insufflation during colonoscopy in the minimally sedated patients (ClinicalTrials.gov Identifier NCT00785889).

Options for screening colonoscopy without sedation: sequel to a pilot study in U.S. veterans.

BACKGROUND: Sedation on demand combined with a novel water infusion technique enabled 23 of 44 veterans to complete screening colonoscopy without sedation. OBJECTIVE: With use of the usual air insufflation technique, we determined the proportion of patients who could complete colonoscopy without sedation. DESIGN: Retrospective review of prospectively collected data in a performance improvement project to minimize the burden of sedation. SETTING: A Veterans Affairs open access screening colonoscopy program. SUBJECTS: Ninety-three consecutive veterans who accepted on-demand sedation or scheduled no sedation. METHOD: Usual air insufflation during colonoscope insertion. Medications were administered at the veteran's request. RESULTS: Twenty-three veterans chose scheduled unsedated colonoscopy; 22 were completed without sedation. Sedation on demand enabled 54 to complete the procedure without medications; 16 requested medications to complete colonoscopy. Nurses' expectations indicated that the choices were credible options. CONCLUSIONS: Options for screening colonoscopy without sedation combined with usual air insufflation are feasible among U.S. veterans. Confirmation by randomized controlled trial and evaluation of the impact on institutional costs and patient adherence to screening and surveillance colonoscopy deserve to be considered.