Discussion

ERCP remains an important diagnostic and therapeutic tool in the investigation and management of hepato-pancreatico-biliary disorders. The move away from diagnostic ERCP and introduction of new technologies have led to longer and more complex procedures being undertaken.

Our study identified 161 ERCPs performed using propofol sedation, representing 22% of our annual ERCP caseload. As expected, ERCPs performed under propofol were more complex, as demonstrated by the increased number of Cotton grade 3–4 cases, reflecting the selection of patients with expected longer and less well-tolerated procedures (eg, cholangioscopy, SOM, ERCP in altered anatomy, pancreatic endotherapy). Patients undergoing propofol sedation were younger. This may be explained by the large number of patients undergoing SOM, who anecdotally may tolerate procedure under sedation poorly. The number of ASA grade 1–2 status patients was similar between the two groups and was an expected finding because patients are not primarily selected for propofol on the basis of comorbidity. At UCLH, patients with severe comorbidity, severe respiratory disease or high BMI are more likely to have a full GA. Direct patient request accounted for 8% of cases performed using propofol. There is now an increasing awareness among patients that propofol is used and available for endoscopic procedures. Patient request for propofol sedation will continue to increase.

We used a combination of propofol and remifentanyl because of their combined ability to provide deep sedation, reflex obtundation and good operator conditions, while both being very short acting so quickly reversed on infusion cessation. These properties are important because the patients are positioned semiprone and have no airway support. Apnoea and airway obstruction are the most important risks of deep propofol sedation. In experienced hands, they are usually averted by simple airway manoeuvres (chin lift and jaw thrust) and reduction or cessation of the sedative infusion. However, in a small group (eight patients in our study), further airway adjuncts and ventilatory support were required up to and including intubation and ventilation. For this reason, it is our policy to have all the equipment in the room, checked and ready for use, to deliver general anaesthesia. The narrow therapeutic window and serious nature of the complications of deep propofol sedation warrant the use of senior anaesthetists, experienced with its use and accompanied by trained assistants, in our opinion. Patients at high risk of airway complications (the morbidly obese and those with known or suspected difficult airways) and those with severe cardiorespiratory compromise should be considered for formal general anaesthesia with endotracheal intubation due to the increased level airway and ventilatory control it offers.

Midazolam, in low dose, was used at the discretion of the anaesthetist for two indications. First, it was used as an anxiolytic and second, to reduce the incidence of awareness. The incidence of awareness during propofol sedation is low and no patient in our study complained of being aware during the procedure. However, as it is not general anaesthesia, no guarantee regarding awareness should be given to patients prior to propofol sedation.

In a study of nearly 800 patients undergoing endoscopic procedures with use of propofol, 336 of whom underwent ERCP, 87% of patients showed no response to endoscopic intubation.8 Premature termination of the procedure occurred in <1% of cases. Although this study provided no specific data regarding (propERCP), the authors concluded that propofol can be used safely for endoscopic procedures when administered by a trained professional. The study did highlight the need for caution and an increased risk of airway modifications in male patients, patients' ASA ≥3 and patients with an increased BMI.8 UK guidelines mandate that the delivery of propofol during endoscopic procedures is by an experienced anaesthetist.5

Nearly 60% of our cases were tertiary referrals from other hospitals. The majority of these referrals were for complex procedures not offered in the referring hospitals. However, 11% of cases had also failed previously at the referring hospital. The routine availability of a propERCP lists is, therefore, an important facility if one is offering a service. The great majority of propofol ERCPs were non-urgent, and the availability of propERCP may not be essential for all ERCP units, as long as this service is available locally/within a network. This is important when developing local pathways and local networks for ERCP provision.

In France and Germany, propofol sedation is the standard of care for ERCP. Some centres within the UK have now adopted propERCP as their standard of care.9 The use of propofol reduces patient movement and discomfort, which possibly may then reduce the risk of procedure-related complications, and be associated with higher postprocedure patient satisfaction compared with conscious sedation.10 In our data, endoscopic complication rates were comparable between the two groups (7% propERCP vs 5% sedERCP, p=0.2). The patient cohort in this study falls into a high-risk category for endoscopic complications and consists of technically challenging cases as represented by the large numbers of Cotton grade 3–4 cases across both groups.

Although our unplanned hospital length of stay (ie, greater than the anticipated overnight stay) in the propERCP group may seem high, all 27 patients that were identified had undergone SOM. SOM is now a declining indication in our unit following the publication of the EPISOD study.11 Results from a Cochrane review have demonstrated a better recovery profile among patients receiving propofol, but no difference with regards to safety, when compared with the use of midazolam and opioid.12 Our data demonstrated similar complication rates in both groups. Anaesthetic complications occurred in eight patients, all of which related to recognised complications of deep sedation. Although three patients required intubation and ventilation, no patient required admission to the intensive care unit for ongoing respiratory support.

At our institution, we have seven dedicated ERCP lists, two of which are propofol assisted. The remaining five lists are therefore performed with the use of conscious sedation only. The cost of a consultant anaesthetist and a band 6 operating department assistant (ODA) for 4 h at UCLH is approximately £1000.00 per list. As all cases are performed within the endoscopy department, no extra costs are incurred. This, however, will be an underestimate as it does not take into account the cost of the preassessment clinic or the reduced numbers of procedures per list. All of these aspects need to be considered and incorporated when calculating the financial implications of providing this service.

Another key finding from our study was that 8% of our cases undergoing propERCP were due to direct patient request at the index ERCP. If weekly propERCP lists are not feasible, then a monthly list may be more realistic. This strategy has been successfully introduced by units in the UK incorporating other endoscopic procedures.13

In conclusion, propERCP may enhance patient outcome within an ERCP service and may be particularly useful if one is undertaking complex ERCPs (Cotton grade ≥3). PropERCP appears safe with comparable endoscopic and anaesthetic/sedation-related complication rates. The demand for propERCP is likely to rise as patients and clinicians request propofol sedation for ERCP. The provision and the availability of propERCP need to be addressed by units and networks providing this service.