Reply to Külling et al.

We thank Külling et al. for their interest in the Guidelines on nonanesthesiologist administration of propofol (NAAP) for gastrointestinal endoscopy, issued by the European Society of Gastrointestinal Endoscopy, the European Society of Gastroenterology and Endoscopy Nurses and Associates, and the European Society of Anaesthesiology [1] [2] [3].

The Evidence level 1++ for the statement “in the vast majority of NAAP studies, propofol was administered by a person who had patient sedation as his/her sole task” (section 6.2.1) is based on high-quality meta-analyses, as defined in the list of evidence levels and recommendation grades (Table 1). The recommendation grade A is in agreement with the evidence level, as also defined in Table 1. The same applies for blood pressure monitoring (section 6.2.2). Our recommendations about staff and monitoring requirements indeed replicate modalities of propofol administration that were used in the trials demonstrating the safety of NAAP. We did not recommend less-stringent staff and monitoring requirements due to the lack of high-quality studies showing that less-stringent requirements are equally safe (e. g. NAAP with two staff members present in the room including the endoscopist is as safe as with three staff members; monitoring with an oxymeter only is as safe as with an oxymeter and blood pressure measurement).

The articles mentioned by Külling et al. were carefully evaluated during the elaboration of the Guideline. The observational study performed and cited by Külling et al. (27 071 esophagogastroduodenoscopy [EGD] and colonoscopy procedures) was judged as providing insufficient evidence with regard to safety [4] [5]. Examples of criticism made toward that study include: (i) the fact that blood pressure measurement was not used in the vast majority of patients does not mean that patients did not suffer from hypotension; (ii) there was no standard follow-up after patient discharge (e. g. evaluation for side-effects); (iii) no automated recording of oxygen desaturation was used. In addition to this, it seems that the study was not approved by an ethics committee and it is unclear whether patients were informed that the reduced monitoring/staffing facilities used were significantly different from the current standards, including those promoted by the American Society of Gastrointestinal Endoscopy (ASGE) and other societies. The prospective observational study performed by Yusoff et al. included a best-case scenario with low-risk patients (ASA 1 – 2) and a long run-in period with anesthesiologists [6]. As mentioned by the authors, the sample size of 500 patients may not have sufficient power to detect rare but potentially devastating complications. The study performed by Cohen et al. was retrospective and therefore provides limited evidence. Furthermore, the same author recently promoted nurse-administrated propofol sedation in a letter to the Editor. His definition of nurse-administrated propofol sedation is “a nurse, working under the supervision of an endoscopist, is responsible solely for administrating propofol to a patient and for monitoring the patient during sedation” [7]. The Guideline committee rated all these three studies as low evidence based on these above-mentioned methodological limitations.

The statement from the ASGE cited by Külling et al. that “for patients receiving moderate sedation the assistant who administers the sedatives and monitors the patient may also perform minor, interruptible tasks (e. g. biopsy or polypectomy)” does not apply to propofol administration [8]. Indeed, that article clearly indicates (Table 5; Recommendations for propofol use during endoscopy; point 2) that NAAP requires “trained personnel dedicated to the uninterrupted monitoring of the patient’s clinical and physiologic parameters throughout the procedure” [8].

The recently published American guideline also cited by Külling et al. is less clear because it effectively states that for patients receiving moderate sedation “once the patient’s level of sedation and vital signs are stable, the registered nurse may perform minor, interruptible tasks” [9]. However, in the following paragraph, it states that if “deep sedation is performed by the administration of propofol by a registered nurse … a second assistant is required for technical assistance during the procedure”. The difficulty arises from the fact that propofol used as a single drug cannot be targeted to moderate sedation for endoscopy [10]. Indeed, Külling et al. acknowledged in their observational study of 27 071 endoscopy procedures, including a majority of EGDs (14 856) that “many EGD patients achieved deep sedation, whereas most colonoscopies were performed under moderate sedation with some patients experiencing occasional brief periods of deep sedation” [4].

As underlined by Külling et al., NAAP has become more widespread in Switzerland but not always in the conditions reported by these authors: their observational study has even prompted Swiss endoscopists to write, in a letter to the Editor, a word of caution about the limited use by these authors of monitoring equipment [11].

As propofol will be used more widely, including for simple procedures such as colonoscopy in ASA 1 and 2 patients, we hope that high-quality studies will investigate the questions of minimum staffing and monitoring during NAAP in the near future. Such prospective trials will be considered at the time of the next Guideline update.

References

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• 2 Dumonceau J M, Riphaus A, Aparicio J R. et al . European Society of Gastrointestinal Endoscopy, European Society of Gastroenterology and Endoscopy Nurses and Associates, and the European Society of Anaesthesiology Guideline: Non-anesthesiologist administration of propofol for GI endoscopy.  Endoscopy. 2010;  42 960-974
• 3 Dumonceau J M, Riphaus A, Aparicio J R. et al . European Society of Gastrointestinal Endoscopy, European Society of Gastroenterology and Endoscopy Nurses and Associates, and the European Society of Anaesthesiology Guideline: Non-anaesthesiologist administration of propofol for GI endoscopy.  Eur J Anaesth. 2010;  27 1016-1030
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• 7 Cohen L B. Nurse-administered propofol sedation for upper endoscopic ultrasonography: not yet ready for prime time.  Nat Clin Pract Gastroenterol Hepatol. 2009;  6 76-77
• 8 Lichtenstein D R, Jagannath S, Baron T H. et al . Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy. Sedation and anesthesia in GI endoscopy.  Gastrointest Endosc. 2008;  68 815-826
• 9 Jain R, Ikenberry S O, Anderson M A. et al . Standards of Practice Committee of the American Society for Gastrointestinal Endoscopy. Minimum staffing requirements for the performance of GI endoscopy.  Gastrointest Endosc. 2010;  72 469-470
• 10 Rex D K. Review article: moderate sedation for endoscopy: sedation regimens for non-anaesthesiologists.  Aliment Pharmacol Ther. 2006;  24 163-171
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