Efficiency in endoscopy centers

Sedation in the Ambulatory Endoscopy Center: Optimizing Safety, Expectations and Throughput

In the United States, sedation and analgesia are the standard of practice when endoscopic procedures are performed in the ambulatory endoscopy center. Over the last 30 years, there has been a dramatic shift of endoscopic procedures from the hospital outpatient department to ambulatory endoscopy centers. This article will discuss sedation and analgesia in the ambulatory endoscopy center as it relates to optimizing safety, patient expectations, and efficiency.

Factors influencing challenging colonoscopies during anesthesiologist-assisted deep sedation

BACKGROUND/AIM

Increased demand for colon cancer screening procedures can significantly impact on routine colonoscopy management at dedicated facilities, prompting a review of the factors that can negatively affect workflow. Although potential adverse effects and impact on costs of deep sedation have been documented elsewhere, this study focuses on variables that can influence performance of colonoscopy in deep sedation and interfere with normal procedure scheduling in settings where the presence of an anesthesiologist is mandatory.

PATIENTS AND METHODS

We performed a cross-sectional study of the activities of a colonoscopy screening unit, applying Bayesian Network (BN) analysis, designed to assess interdependencies among variables that can affect a process in complex, multidimensional systems. The study was performed at a teaching hospital where endoscopists and anesthesiologists of varying work experience operate on a rota basis. During a six-month period, we analyzed 1485 consecutive colonoscopies performed under deep propofol sedation, administered by an anesthesiologist via hand-controlled syringe. The BN was constructed with the variables: Gender, age, ASA status, bowel preparation, baseline blood pressure, endoscopist's experience, anesthesiologist's experience, presence of polypectomy, and the target node, "challenging procedure." This previously undefined category refers to any events disrupting the scheduled rota.

RESULT AND CONCLUSION

Two distinct networks were identified. One deals mainly with relationships among the variables, patients' demographic and clinical characteristics (procedures with polypectomy, ASA and baseline blood pressure). The other explains relationships among the variables, "challenging procedure," bowel preparation, and endoscopist's experience. The factors associated with the anesthesiologist's activity do not influence challenging colonoscopies.

Difficult colonoscopies in the propofol era

BACKGROUND

To study the relationship between endoscopic practice and adverse events during colonoscopy under standard deep sedation induced and monitored by an anesthetist.

METHODS

We investigated the routine activity of an endoscopy center at the Padova University teaching hospital. We considered not only endoscopic and cardiorespiratory complications, but also the need to use high-dose propofol to complete the procedure, and the inability to complete the procedure. Variables relating to the patient's clinical conditions, bowel preparation, the endoscopist's and the anesthetist's experience, and the duration of the procedure were input in the model.

RESULTS

617 procedures under deep sedation were performed with a 5% rate of adverse events. The average dose of propofol used was 2.6 ± 1.2 mg/kg. In all, 14 endoscopists and 42 anesthetists were involved in the procedures. The logistic regression analysis identified female gender (OR=2.3), having the colonoscopy performed by a less experienced endoscopist (OR=1.9), inadequate bowel preparation (OR=3.2) and a procedure lasting longer than 17.5 minutes (OR=1.6) as the main risk factors for complications. An ASA score of 2 carried a 50% risk reduction (OR=0.5).

DISCUSSION AND CONCLUSIONS

Our model showed that none of the variables relating to anesthesiological issues influenced which procedures would prove difficult.

Computer-assisted personalized sedation

The American Society for Gastrointestinal Endoscopy (ASGE) Technology Committee provides reviews of new or emerging endoscopic technologies that have the potential to have an impact on the practice of GI endoscopy. Evidence-based methodology is used, with a MEDLINE literature search to identify pertinent preclinical and clinical studies on the topic, and a MAUDE (Manufacturer and User Facility Device Experience; U.S. Food and Drug Administration Center for Devices and Radiological Health) database search to identify the reported complications of a given technology. Both are supplemented by accessing the "related articles" feature of PubMed and by scrutinizing pertinent references cited by the identified studies. Controlled clinical trials are emphasized but, in many cases, data from randomized, controlled trials are lacking. In such cases, large case series, preliminary clinical studies, and expert opinions are used. Technical data are gathered from traditional and Web-based publications, proprietary publications, and informal communications with pertinent vendors. For this review, the MEDLINE database was searched through January 2010 using the keywords "computer," "computerized," "computer-assisted," "sedation," "propofol." Reports on Emerging Technology are drafted by 1 or 2 members of the ASGE Technology Committee, reviewed and edited by the committee as a whole, and approved by the Governing Board of the ASGE. These reports are scientific reviews provided solely for educational and informational purposes. Reports on Emerging Technology are not rules and should not be construed as establishing a legal standard of care or as encouraging, advocating, requiring, or discouraging any particular treatment or payment for such treatment.

Reducing access times for an endoscopy department by an iterative combination of computer simulation and linear programming

To reduce the access times of an endoscopy department, we developed an iterative combination of Discrete Event simulation and Integer Linear Programming. We developed the method in the Endoscopy Department of the Academic Medical Center in Amsterdam and compared different scenarios to reduce the access times for the department. The results show that by a more effective allocation of the current capacity, all procedure types will meet their corresponding performance targets in contrast to the current situation. This improvement can be accomplished without requiring additional equipment and staff. Currently, our recommendations are implemented.

Reducing access times for an endoscopy department by an iterative combination of computer simulation and linear programming

To reduce the access times of an endoscopy department, we developed an iterative combination of Discrete Event simulation and Integer Linear Programming. We developed the method in the Endoscopy Department of the Academic Medical Center in Amsterdam and compared different scenarios to reduce the access times for the department. The results show that by a more effective allocation of the current capacity, all procedure types will meet their corresponding performance targets in contrast to the current situation. This improvement can be accomplished without requiring additional equipment and staff. Currently, our recommendations are implemented.

A randomized, controlled, double-blind trial of patient-controlled sedation with propofol/remifentanil versus midazolam/fentanyl for colonoscopy

BACKGROUND

Patient-controlled sedation (PCS) with propofol has been advocated as a method for dealing with the narrow therapeutic window for moderate sedation, but previous studies have methodologic limitations. We hypothesized that, by using remifentanil in conjunction with propofol and using PCS in both arms of the study, we could demonstrate marked improvements in facility use compared with fentanyl plus midazolam.

METHODS

Fifty patients undergoing elective colonoscopy were randomized (with concealed allocation) to midazolam/fentanyl (group MF) or propofol/remifentanil (group PR) administered via PCS. Time intervals for sedation and recovery, perceptions by patient, nurse, and gastroenterologist, and need for anesthesiologist intervention were assessed.

RESULTS

Group PR patients were sedated and recovered significantly more rapidly than did group MF (P < 0.0001). In the group PR, recovery room time was actually shorter than procedure room time. Patient, nurse, and gastroenterologist perceptions were equivalent between the groups. Two patients in group PR required anesthesiologist intervention for arterial desaturation exceeding the primary safety end point.

CONCLUSIONS

PCS with propofol/remifentanil yields superior facility throughput compared with midazolam/fentanyl when used in an appropriate care setting.