Who is willing to undergo endoscopy without sedation: patients, nurses, or the physicians?

Impact of anxiety on sedative medication dosage in patients undergoing esophagogastroduodenoscopy

Introduction

Esophagogastroduodenoscopy (EGD) is a diagnostic method used in the investigation of upper gastrointestinal system diseases. A high level of anxiety of patients who undergo EGD increases the duration of the procedure and the sedation and analgesic requirements. Sedation is used to increase patient comfort and tolerance by reducing the anxiety and pain associated with endoscopic procedures.

Aim

In this study, the effect of anxiety scores on medication doses was investigated in patients who underwent EGD under sedation.

Material and methods

A psychiatrist, an endoscopist and an anesthesiologist conducted a prospective observational study blindly to investigate the effect of pre-procedural (before EGD) anxiety level on medication doses for sedation. Patients were divided into two groups, with and without additional medication doses.

Results

The study included 210 consecutive patients who underwent EGD under sedation. The average STAI-S score was 40.28 and the average STAI-T score was 40.18. There was no relationship between anxiety scores and gender (p = 0.058, p = 0.869). Statistically significant results were obtained for anxiety scores with additional sedation dosing (p < 0.05). It was observed that an additional dose of medication was affected by age, body mass index and anxiety scores (p < 0.005). Patients who were young, had a low body mass index and had high anxiety scores had significantly higher additional dose requirements.

Conclusions

The medications used for sedation during EGD may be inadequate or an additional dose of medication may be needed for patients who have higher anxiety scores, younger age, and lower body mass index.

Sedation-analgesia in elective colonoscopy: propofol-fentanyl versus propofol-alfentanil

BACKGROUND AND OBJECTIVES

Sedation-analgesia is recommended for comfortable colonoscopy procedures, which are invasive and can be painful. This study aimed to compare the combinations of propofol-alfentanil and propofol-fentanyl for sedation-analgesia in elective colonoscopy patients.

METHODS

This prospective and randomized study was planned in ASA I-II groups and included 80 patients between the ages of 18 and 65 years. Sedation-analgesia induction was performed as 1 μg.kg-1 fentanyl, 1 mg.kg-1 propofol in the propofol-fentanyl group (Group PF) and 10 μg.kg-1 alfentanil, 1 mg.kg-1 propofol in the propofol-alfentanil group (Group PA). Patients’ scores were limited to 3-4 values on the Ramsey Sedation Scale (RSS) by 0.5 mg.kg-1 bolus additional doses of propofol in sedation-analgesia maintenance. We recorded demographical data, heart rate, mean arterial pressure (MAP), oxygen saturation of hemoglobin (SpO2), RSS value, colonoscopy time, total dose of propofol, complications, recovery time, and discharge time, as well as colonoscopist and patient satisfaction scores.

RESULTS

MAP at the 15th minute in Group PA was signifi cantly higher than in Group PF (p = 0.037). Group PA’s beginning mean heart rate was higher than the mean heart rate at subsequent readings (p = 0.012, p = 0.002). The mean total propofol dose of Group PA was signifi cantly higher than the total dose of Group PF (p = 0.028). The mean recovery time of Group PA was signifi cantly longer than that of Group PF (p = 0.032).

CONCLUSION

Fentanyl provides better operative conditions and reduces the need for additional propofol doses. These advantages cause a shorter recovery time. Therefore, propofol-fentanyl is superior to the propofol-alfentanil for sedation-analgesia in colonoscopy.

Sedation-analgesia in elective colonoscopy: propofol-fentanyl versus propofol-alfentanil

BACKGROUND AND OBJECTIVES

Sedation-analgesia is recommended for comfortable colonoscopy procedures, which are invasive and can be painful. This study aimed to compare the combinations of propofol-alfentanil and propofol-fentanyl for sedation-analgesia in elective colonoscopy patients.

METHODS

This prospective and randomized study was planned in ASA I-II groups and included 80 patients between the ages of 18 and 65 years. Sedation-analgesia induction was performed as 1 μg.kg(-1) fentanyl, 1mg.kg(-1) propofol in the propofol-fentanyl group (Group PF) and 10 μg.kg(-1) alfentanil, 1mg.kg(-1) propofol in the propofol-alfentanil group (Group PA). Patients' scores were limited to 3-4 values on the Ramsey Sedation Scale (RSS) by 0.5mg.kg(-1) bolus additional doses of propofol in sedation-analgesia maintenance. We recorded demographical data, heart rate, mean arterial pressure (MAP), oxygen saturation of hemoglobin (SpO2), RSS value, colonoscopy time, total dose of propofol, complications, recovery time, and discharge time, as well as colonoscopist and patient satisfaction scores.

RESULTS

MAP at the 15(th) minute in Group PA was significantly higher than in Group PF (p = 0.037). Group PA's beginning mean heart rate was higher than the mean heart rate at subsequent readings (p = 0.012, p = 0.002). The mean total propofol dose of Group PA was significantly higher than the total dose of Group PF (p = 0.028). The mean recovery time of Group PA was significantly longer than that of Group PF (p = 0.032).

CONCLUSION

Fentanyl provides better operative conditions and reduces the need for additional propofol doses. These advantages cause a shorter recovery time. Therefore, propofol-fentanyl is superior to the propofol-alfentanil for sedation-analgesia in colonoscopy.

Health care providers' acceptance of unsedated colonoscopy before and after a state-of-the-art lecture on the feasibility of the option

BACKGROUND/AIM

The impact of education on acceptance of unsedated colonoscopy by health care providers is unknown. To test the hypothesis that knowledge imparted by a lecture on unsedated colonoscopy is associated with its enhanced acceptance.

SETTINGS AND DESIGN

At the State-of-the-Art Lecture on "Unsedated colonoscopy: Is it feasible?" presented at the 8 th Pan-Arab Conference on Gastroenterology, February, 2011, Riyadh, Saudi Arabia, a questionnaire survey of the audience was undertaken.

MATERIALS AND METHODS

An expectation questionnaire was administered before and after the lecture. Attendees responded anonymously.

STATISTICAL ANALYSIS USED

The responses of a convenient sample of 49 attendees who provided completed responses to the questionnaire both before and after the lecture were analyzed. Data are expressed as frequency counts and means±SEM. Repeated measures analysis of variance (ANOVA), ANOVA with contrasts and Chi-square analysis (Statview II Program for Macintosh computers) were used to assess the data. A P value of <0.05 is considered significant.

RESULTS AND CONCLUSIONS

The mean±SEM credibility score (maximum possible score=50) was 25.8 ± 1.8 before and 33.3 ± 2.1 after the lecture, with a significant improvement in mean score of 7.5 ± 1.3 (P=0.001, paired t test). Nineteen (39%) respondents were not willing to consider unsedated colonoscopy for themselves before the lecture. This number decreased to 13 (27%) after the lecture. Before the lecture only 4 (8%) respondents were willing to consider unsedated colonoscopy for themselves. After the lecture this number increased to 8 (16%). The data suggest education of healthcare professionals regarding the feasibility of unsedated colonoscopy appears to enhance its acceptance as a credible patient care option at a Pan-Arab Gastroenterology Conference.

Unsedated colonoscopy: is it feasible?

Unsedated colonoscopy has been an evolving subject ever since its initial description four decades ago. Failure in unsedated diagnostic cases due to patient pain led to the introduction of sedation. Extension to screening cases, albeit logical, created a sedation-related barrier to colonoscopy screening. In recent years a water method has been developed to combat the pain during unsedated colonoscopy in the US. In randomized controlled trials the water method decreases pain, increases cecal intubation success, and enhances the proportion of patients who complete unsedated colonoscopy. The salvage cleansing of suboptimal bowel preparation by the water method serendipitously may have increased the detection of adenoma in both unsedated and sedated patients. The state-of-the-art lecture concludes that unsedated colonoscopy is feasible. The hypothesis is that recent advances, such as the development of the water method, may contribute to reviving unsedated colonoscopy as a potentially attractive option for colon cancer screening and deserves to be tested.

Is there a place for sedationless colonoscopy?

Usedated colonoscopy is routinely available in many parts of the world. In the US, only educated professionals appear to be knowledgeable enough to request the unsedated option. Colonoscopists have also been willing to perform unsedated colonoscopy when a patient presents without an escort after undergoing bowel purge preparation. While the actual side-effects of sedation are minimal, the escort requirement and time burden of sedation are barriers to the uptake of screening colonoscopy in the US. The recent trend of deep sedation with propofol for screening colonoscopy increases the efficiency of the colonoscopists at significant costs (e.g. anesthetist reimbursement). The options of as needed and on demand sedation permit patients to complete colonoscopy without sedation. The latter appears to be potentially less coercive. Nurses with experience in the unsedated options recognize the benefit of the quick turn-around of the examination room and shortened occupancy of the recovery area. Discharge planning can be optimized due to absence of amnesia. Patients completing unsedated colonoscopy have given their endorsement of the options. Pain and discomfort continue to limit the success rate of cecal intubation to about 80%. A recently described water method (warm water infusion in lieu of air insufflation combined with removal of all residual colonic air by suction and residual feces by water exchange) has the potential of decreasing procedural discomfort and enhancing cecal intubation in unsedated colonoscopy. The availability of the novel water method assures colonoscopists that high success rate of cecal intubation can be achieved in the unsedated patients.

Sedation-risk-free colonoscopy for minimizing the burden of colorectal cancer screening

Unsedated colonoscopy is available worldwide, but is not a routine option in the United States (US). We conducted a literature review supplemented by our experience and expert commentaries to provide data to support the use of unsedated colonoscopy for colorectal cancer screening. Medline data from 1966 to 2009 were searched to identify relevant articles on the subject. Data were summarized and co-authors provided critiques as well as accounts of unsedated colonoscopy for screening and surveillance. Diagnostic colonoscopy was initially developed as an unsedated procedure. Procedure-related discomfort led to wide adoption of sedation in the US, although unsedated colonoscopy remains the usual practice elsewhere. The increased use of colonoscopy for colorectal cancer screening in healthy, asymptomatic individuals suggests a reassessment of the burden of sedation in colonoscopy for screening is appropriate in the US for lowering costs and minimizing complications for patients. A water method developed to minimize discomfort has shown promise to enhance outcomes of unsedated colonoscopy. The use of scheduled, unsedated colonoscopy in the US appears to be feasible for colorectal cancer screening. Studies to assess its applicability in diverse practice settings deserve to be conducted and supported.

Pilot feasibility study of the method of water infusion without air insufflation in sedated colonoscopy

One study in sedated patients demonstrated a reduction in pain score but not midazolam dosage when warm water infusion was used to manage colonic spasm. We describe pilot data with a modified warm water infusion technique. We tested the hypothesis that patients receiving even only half of the usual dose of sedation medications would have acceptable cecal intubation and tolerate the procedure well, based on retrospective review of prospectively collected data from a single Veterans Affairs (VA) medical center. Group 1 included 32 consecutive patients who received full-dose and group 2 included 43 consecutive patients who received half-dose premedication. Insertion of colonoscope was aided by warm water infusion in lieu of air insufflation. Pain scores during insertion, cecal intubation rate, and total amount of medications were monitored. The novel technique permitted equal cecal intubation rate at reduced total dose of medications. Pain scores were not significantly different. The uncontrolled nonrandomized observational nature of the data is one limitation. The nonsignificant difference in pain scores may be affected by a type II error. These pilot data suggest that insertion is feasible without air when water infusion is used. The novel technique may be a useful adjunct for minimizing the dosage of sedation medications without adversely affecting cecal intubation. Further study is needed to compare air insufflation and water infusion with regard to patient tolerance and success, particularly in the presence of an on-demand sedation policy.

Safer sedation practice may not translate into improvements in endoscopic outcomes

INTRODUCTION

Although the literature surrounding sedation practice and endoscopic outcomes remains sparse and controversial, there have been a number of stringent guidelines issued regarding sedation use in endoscopy.

AIMS

To assess the impact of changes to enhance safer sedation practice on endoscopic outcomes.

METHODS

Sedation practice was audited in 7234 consecutive gastrointestinal endoscopic procedures in 2004 and protocols for enhancing safer sedation practice were introduced. These included; introduction of a unit sedation policy, exchange of midazolam 10 mg vials to 5 mg repacked syringes, adverse events recording of midazolam use of greater than 5 mg and reversal agents, more stringent patient monitoring procedures and endoscopists education and feedback. A reaudit of 7071 procedures was performed in 2006. Outcomes audited the included midazolam doses, patient intolerance, 30-day postprocedure mortality, reversal agent use and total adverse events.

RESULTS

Sedation doses were reduced substantially after intervention [mean midazolam dose (SD): 4.9 mg (2.5) in 2004 vs. 2.9 mg (1.2) in 2006; P<0.0001] with no endoscopist using a mean greater than 5 mg in 2006 compared with 19% in 2004 (P=0.005). The use of reversal agents (0.6 vs. 0.7% for 2004 and 2006, respectively; P=0.74), mortality (1.0 vs. 1.3%; P=0.23) and the adverse events (1.7 vs. 2%; P=0.44) were similar. Unsuccessful procedures because of patient intolerance increased from 0.1 to 1.9% (P<0.0001).

CONCLUSION

Although protocols to enhance safer sedation practice substantially reduced sedation doses used; this did not, however, translate into improved endoscopic outcomes. Moreover, incomplete procedures because of poor tolerance increased.

Promoting informed choice of unsedated colonoscopy: patient-centered care for a subgroup of US Veterans

BACKGROUND

In the United States, colonoscopy is usually performed under sedation. In practice, 2.3-7% actually requested unsedated colonoscopy and 1.4% received it because of no escorts. Efforts to increase usage would likely require increased patient counseling and education.

AIM

We tested the hypothesis that knowledge conveyed by education-a key attribute of patient-centered care-is associated with acceptance of the "non-usual" option.

METHODS

After patients underwent discussions and expressed acceptance of sedated colonoscopy, the pros and cons of and local experience with unsedated colonoscopy were added. The patients who changed from accepting sedated to unsedated colonoscopy and outcomes of their examinations were recorded.

RESULTS

From January to November 2006, 49 of 176 consecutive patients (28%) changed their choice from sedated to unsedated colonoscopy after being informed of the latter. Forty-eight had satisfactory bowel preparation. Cecal intubation rate was 93.7% (45 of 48). Thirty-six reported good experience and 43, likely to repeat. Cecal intubation, withdrawal, and discharge times were 23.0 +/- 1.4 min, 15.0 +/- 1.0 min, and 5.0 +/- 0.5 min, respectively (n = 45). Ability to communicate with the colonoscopist during and after the examination was the most frequently ranked reason for choosing unsedated colonoscopy.

CONCLUSION

Our uncontrolled, non-randomized, single-site observational data revealed that for selected veterans, acceptance of unsedated colonoscopy coincides with knowledge of the option dispensed by patient counseling and education.

Unsedated colonoscopy introduced to ensure access is acceptable to a subgroup of veterans

BACKGROUND

Nurses for monitoring and recovery are required for sedated colonoscopy. A nursing shortage necessitated discontinuation of sedated colonoscopy at a VA academic training program.

AIM

Elements of a case series that documented acceptance of unsedated colonoscopy are reviewed to raise awareness of the feasibility of this option.

METHOD

The pros and cons of sedation and no sedation were summarized. After discussion, patients who chose the unsedated option were scheduled for examination locally while those who desired sedation were scheduled at another VA site. Colonoscopy was performed by supervised trainees.

RESULTS

From September 2002 to June 2005 scheduled unsedated colonoscopy was accepted by 145 of 483 veterans. Cecal intubation was achieved in 81%. Thus, of the cohort 30% had local access to and 24% completed unsedated colonoscopy. Implementation of unsedated colonoscopy obviated the need for two registered nurses previously required for sedated colonoscopy.

CONCLUSION

Unsedated colonoscopy offered as an option to ensure access was acceptable to a subgroup of our veteran patients. Implementation required less nursing resources. Techniques to enhance the cecal intubation rate of unsedated colonoscopy performed by supervised trainees deserves to be assessed in future studies.

Methods of reducing discomfort during colonoscopy

In the United States sedation for colonoscopy is usual practice. Unsedated colonoscopy is limited to a small proportion of unescorted patients and those with a personal preference for no sedation. Over 80% of patients who accept the option of as-needed sedation can complete colonoscopy without sedation. Colonoscopy in these unsedated patients is performed with techniques similar to those used in the sedated patients. Uncontrolled observations indicate willingness to repeat colonoscopy amongst these patients was correlated significantly with low discomfort score during the examination. Methods reported to minimize patient discomfort or enhance cecal intubation during sedated or unsedated colonoscopy included use of pediatric colonoscope, variable stiffness colonoscope, gastroscope, and inhalation of nitrous oxide or insufflation of carbon dioxide, hypnosis, music, audio distraction, or simply allowing the patients to participate in administration of the medication. Research focusing on confirming the efficacy of a simple inexpensive nonmedication dependent method for minimizing discomfort will likely improve the outcome of care and more importantly will ensure compliance with future surveillance in patients accepting the unsedated option.

Involvement of trainees in routine unsedated colonoscopy: review of a pilot experience

BACKGROUND

Unsedated colonoscopy is not required by the Accreditation Council of Graduate Medical Education in the curriculum of GI trainees.

OBJECTIVE

We describe our pilot experience with trainee participation in unsedated colonoscopy.

DESIGN

A retrospective review of a performance improvement program to provide access to colonoscopy.

SETTING

A Veteran's Affair ambulatory care facility that discontinued sedated colonoscopy because of a nursing shortage.

PATIENTS

A total of 145 of 483 patients who chose unsedated colonoscopy after both sedated and unsedated options were discussed.

INTERVENTIONS

GI fellows performed unsedated colonoscopy under the supervision of the attending physician.

MAIN OUTCOME MEASUREMENTS

Cecal intubation rate, patient assessment of the reasons for the choice, the unsedated experience, willingness to have another colonoscopy, and the rate of return for unsedated colonoscopy among eligible patients.

RESULTS

Cecal intubation was achieved in 112 of 145 patients. The adjusted success rate (excluding inadequate bowel preparation and an obstructing lesion) was 81%. The most frequently acknowledged reason for the choice was the ability to communicate with the colonoscopist. Eighty-six patients reported a good experience and were likely to accept another unsedated colonoscopy. To date, all 8 patients eligible for 3-year follow-up successfully completed another unsedated examination.

LIMITATION

An uncontrolled, nonrandomized review in predominantly male older veterans.

CONCLUSIONS

An unsedated colonoscopy might be acceptable to some populations, particularly when communication with clinicians and procedural convenience are highly valued. Involvement of trainees is feasible. Randomized controlled comparisons of sedated and unsedated options in terms of safety (eg, sedation and procedure-related complications) and cost in settings with and without a nursing shortage deserve to be considered.

Conscious sedation for patients undergoing enteroclysis: comparing the safety and patient-reported effectiveness of two protocols

OBJECTIVE

To compare the safety and patient-reported effectiveness of two regimens for conscious sedation during enteroclysis.

MATERIALS AND METHODS

We surveyed two groups of outpatients and retrospectively reviewed procedure records for conscious sedation and complications. Patients were divided into Group One (received sedative/amnesic diazepam), and Group Two, (received amnesic/sedative, midazolam and analgesic fentanyl).

RESULTS

All enteroclyses were successfully completed; there were no hospital admissions due to complications. In Group One (n=106), mean dose of diazepam was 12.7 mg. 25% had oxygen desaturation (n=25), and post-procedure vomiting without aspiration (n=1). 56% of outpatients completed phone surveys, and 68% recalled procedural discomfort. In Group Two (n=45), mean doses were 3.9 mg midazolam and 108 mcg fentanyl. 31% had desaturation (n=13), and post-procedure vomiting without aspiration (n=1). 87% had only a vague recall of the procedure or of any discomfort.

CONCLUSION

A combination of amnesic and fentanyl prevented the recall of discomfort of nasoenteric intubation and infusion in most patients who had enteroclysis compared to diazepam. Most of the patients would undergo the procedure again, if needed.

Small caliber overtube-assisted colonoscopy

AIM: To combine the benefits of a new thin flexible scope with elimination of excessive looping through the use of an overtube.

METHODS: Three separate retrospective series. Series 1: 25 consecutive male patients undergoing unsedated colonoscopy using the new device at a Veteran’s hospital in the United States. Series 2: 75 male patients undergoing routine colonoscopy using an adult colonoscope, pediatric colonoscope, or the new device. Series 3: 35 patients who had incomplete colonoscopies using standard instruments.

RESULTS: Complete colonoscopy was achieved in all 25 patients in the unsedated series with a median cecal intubation time of 6 min and a median maximal pain score of 3 on a 0-10 scale. In the 75 routine cases, there was significantly less pain with the thin scope compared to standard adult and pediatric colonoscopes. Of the 35 patients in the previously incomplete colonoscopy series, 33 were completed with the new system.

CONCLUSION: Small caliber overtube-assisted colonoscopy is less painful than colonoscopy with standard adult and pediatric colonoscopes. Male patients could undergo unsedated colonoscopy with the new system with relatively little pain. The new device is also useful for most patients in whom colonoscopy cannot be completed with standard instruments.

Anaesthesia and sedation for gastrointestinal endoscopy

PURPOSE OF REVIEW

Wide variations exist around the world in the practice of sedation for endoscopy, in terms of the depth of sedation, drug choices, delivery methods and the practitioners involved. These variations are driven by historical, cultural and economic factors. Professional bodies have promulgated guidelines in an attempt to unify and raise standards for sedation and monitoring. Nevertheless, preventable morbidity associated with sedation still occurs. A review of the recent literature is therefore justified.

RECENT FINDINGS

The main themes in this literature are the advent of the widespread use of propofol by non-anaesthesiologists, and particularly non-medical staff; novel methods for administering propofol; the acceptability of endoscopy without sedation; and emerging technologies that obviate the need for endoscopy.

SUMMARY

There is still much scope to research and refine sedation techniques for endoscopy. We believe that the involvement of anaesthesiologists in this research is vital.

Extended flexible sigmoidoscopy performed by colonoscopists for colorectal cancer screening: a pilot study

BACKGROUND

Caecal intubation can be achieved by extended flexible sigmoidoscopy in 32% of patients.

AIM

To assess the feasibility of extended flexible sigmoidoscopy performed by colonoscopists for colorectal cancer screening.

METHODS

We enrolled 41 patients referred for screening flexible sigmoidoscopy. After purging, examination was performed with a colonoscope. All patients completed sigmoidoscopy (success in meeting referral goal); 93% and 71% had examination to the transverse or ascending colon, and caecum, respectively. Overall yield and right-sided polyps was 56% and 27%, respectively. Caecal intubation and complete examination with polypectomy took 6.0 +/- 2.5 and 18.3 +/- 5.1 min, respectively; with no complications. Twelve patients requested colonoscope withdrawal because of discomfort. Although 46% reported moderate to severe discomfort, 39% and 36%, respectively, were definitely or probably willing to repeat flexible sigmoidoscopy.

RESULTS

Unsedated colonoscopy introduced as extended flexible sigmoidoscopy emphasizes the benefits of added yield rather than the negative image of withholding of discomfort relief. The patient can choose to accept the equivalent of an unsedated colonoscopy or reject the option based on perceived discomfort during extended flexible sigmoidoscopy performed by the colonoscopist.

CONCLUSION

Extended flexible sigmoidoscopy is a feasible option in carefully selected patients, fully prepared and by an experienced colonoscopist.

Wireless esophageal pH monitoring: new technique means new questions

INTRODUCTION

The introduction of wireless pH monitoring has been touted as a significant advance in the diagnosis of gastroesophageal reflux and associated disorders. We prospectively enrolled patients in a research registry to assess the feasibility and safety in clinical use.

METHODS

All patients undergoing endoscopy with wireless pH studies (Medtronic Bravo pH system) for a 12-month period starting in April 2004 were prospectively enrolled. Probes were placed 6 cm above the endoscopically localized squamocolumnar junction. Successful completion was defined as at least 24 hours of pH recording. Safety data were obtained by review of patient diaries. All results are given as median with 25% to 75% confidence interval (CI).

RESULTS

A total of 217 studies with endoscopy and capsule placement were performed (65% women; median age, 51 years; range, 42-58 years) and included in the study; 1 patient refused participation in the registry and 5 studies were performed without preceding endoscopy and were excluded from this analysis. The pH study was successfully completed in 95.1%; early capsule detachment (1 hours; CI, 0-5 hours) or receiver malfunction occurred in 7 and 2 cases, respectively. There were no immediate adverse effects; 18 patients (9%) complained about significant chest discomfort, associated with odyno- or dysphagia, requiring removal of the capsule in 3 patients (1.5%). Of the completed studies, 56% were abnormal with 32.2% being abnormal on both days, whereas 16.1% and 6.9% only showed increased acid exposure on day 1 or 2, respectively. The higher likelihood of abnormal results for day 1 was associated with a significantly increased esophageal acid exposure during the first 6 hours after capsule insertion on day 1 (total time with pH < 4: 6.9%; CI, 3.2%-16.5%) compared with the corresponding time on day 2 (5.0%; CI, 0.9%-10.8%; P < 0.01), without differences esophageal acidification during the remaining time or differences in recorded activity.

CONCLUSIONS

Using a large registry of patients with suspected gastroesophageal reflux symptoms, our data show that wireless pH studies can be safely completed in more than 90% of patients. Whereas variability during prolonged recordings should be expected, the significantly higher likelihood of abnormal findings during the initial period of pH monitoring suggests a systematic influence of endoscopy and associated premedication, typically performed prior to capsule insertion, which needs to be considered when pH data are analyzed.