Sedation for endoscopy: the safe use of propofol by general practitioner sedationists

Anthony C Clarke, Louise Chiragakis, Lybus C Hillman and Graham L Kaye
Med J Aust 2002; 176 (4): 158-161. || doi: 10.5694/j.1326-5377.2002.tb04345.x
Published online: 18 February 2002


Objective: To determine the incidence of adverse events related to an endoscopy sedation regimen that included propofol, delivered by general practitioner (GP) sedationists.

Design: Audit of reports of sedation-related adverse events in patients undergoing endoscopy. A sample of 1000 patients' medical records was also reviewed to determine the drugs and dosages used and the proportion of sedations delivered by GPs.

Setting and participants: All patients undergoing gastroscopy and/or colonoscopy from January 1996 to December 2000 in two private endoscopy centres in Canberra. Sedation was provided by GPs or a specialist anaesthetist, in most cases using a drug regimen that included propofol.

Main outcome measures: Incidences of respiratory arrest, airway obstruction, hypoxia requiring intervention, hypotension, and death; number of interventions to correct these events, including extra airway management, bag-mask ventilation, intravenous fluid infusion, endotracheal intubation and the use of reversal agents, and admission to hospital.

Results: 28 472 procedures were performed in the five years. There were 185 sedation-related adverse events (6.5/1000 procedures; 95% CI, 5.6–7.4): 107 for airway or ventilation problems (3.8/1000) and 77 hypotensive episodes (2.7/1000). Respiratory-related adverse events were more common in patients managed by GPs than anaesthetists, but this was not significant (P = 0.1). Interventions were recorded in 234 patients (8.2/1000; 95% CI, 7.2–9.3): 123 to maintain ventilation, and 111 intravenous infusions. GPs were more likely than anaesthetists to intervene to manage respiratory-related adverse events (P = 0.03). Four patients required transfer or admission to hospital. No patients required endotracheal intubation, and there were no deaths.

Conclusions: The GP sedationists encountered a low incidence of adverse events, which they managed effectively. It appears that appropriately selected and trained GPs can safely use propofol for sedation during endoscopy.

Over the past 30 years, gastrointestinal endoscopy has become one of the most commonly performed invasive procedures in clinical practice. Gastroscopy and colonoscopy have become established as the definitive diagnostic procedures for the upper gastrointestinal tract and colon, respectively, and therapeutic applications have advanced considerably. During the year ended June 2000, Medicare alone provided rebates for more than 430 000 examinations.1 During most of these examinations, the subject is sedated to ensure patient comfort and enable the procedure to be completed without interference from patient restlessness.

Although the Australian and New Zealand College of Anaesthetists (ANZCA) and the Gastroenterological Society of Australia (GESA) have published joint guidelines2 that have assisted in standardising sedation, there is still considerable variation in sedation delivery. In many endoscopy units, the endoscopist supervises the sedation, whereas in others a specialist anaesthetist is present. One of the arguments put forward for employing an anaesthetist is that this allows the use of more sophisticated sedating agents such as propofol.

Propofol is a short-acting anaesthetic agent widely used for induction of anaesthesia and as a sedative agent in intensive care settings. Its rapid onset (within 30 seconds) and short half-life (2–4 minutes) make it suitable for use in a day-procedure setting. However, the use of propofol by non-specialist anaesthetists is controversial, as evidenced by a recent editorial in Endoscopy,3 which concluded "The smaller therapeutic ratio seen with propofol means that, in our opinion, there is an inadequate margin of safety when this drug is used by non-anaesthetists".

Over the past five years, propofol has been routinely included in the sedation regimen given by both general practitioners and specialist anaesthetists in our two endoscopy centres in Canberra. This article analyses the safety of the use of low doses of propofol in combination with midazolam and fentanyl by trained GP sedationists.

Endoscopy centre procedures
Patient selection

Patients classified by the American Society of Anesthesiologists4 as grade IV and V (ie, high risk), and patients with major acute emergencies better treated in a major hospital environment, are not treated in the endoscopy centres. Patients identified as being at higher than average risk are selected for the specialist anaesthetists' lists. Therapeutic procedures including polypectomy, stricture dilatation, oesophageal and haemorrhoid band ligation, oesophageal stent placement and percutaneous endoscopic gastrostomy tube placement are performed as indicated. The minimum age of patients treated is 12 years.

Incident reporting program

The centres have a mandatory incident-reporting scheme that requires any adverse event or non-standard treatment to be recorded on an "Incident Report Form".

Sedation-related events that must be reported include:

Interventions that must be recorded include:

Compliance with these requirements is fostered by having a non-punitive response to the results of these reports, and by demonstrating that they lead to organisational changes to assist the clinical staff. All staff understand that they have an obligation to ensure that incident reports are completed. The nurses are particularly helpful in achieving this outcome. Every patient receives a phone call from one of the centre's nursing staff the day after his or her procedure to check on their condition and ensure that the recommended management program is understood. This also provides an opportunity to detect any adverse events.

The incident reports are assessed by the Director of Anaesthesia and at the monthly quality assurance committee meeting. They are also entered into an electronic database to facilitate the development of clinical indicator reports to the Australian Council on Healthcare Standards.


A total of 28 472 procedures were performed from January 1996 to December 2000 (Box 1). Data from the random sample of 1000 patients indicate that GPs administered sedation in almost 80% of cases. The drug doses used are shown in Box 2.


The interventions used to maintain ventilation and blood pressure are shown in Box 4. There were more interventions than adverse events: 16 patients without respiratory difficulties received reversal agents to hasten recovery, and intravenous infusions were delivered to 34 normotensive patients assessed as dehydrated. GPs used these procedures significantly more frequently than anaesthetists (Box 4). GPs were particularly more likely to use drug-reversal agents — all but one of the 53 uses of these drugs was by GPs.


As gastrointestinal endoscopy is performed so frequently, it is vital that it is undertaken as safely as possible. There are surprisingly few published studies that analyse the safety of endoscopy. In 1991, the British Society of Gastroenterology5 carried out a prospective audit of 13 036 gastroscopies performed in 36 hospitals over a four-month period. The survey revealed a mortality of 1 in 2000 for diagnostic procedures and 1 in 100 for therapeutic procedures. These results were attributed to many of the hospitals having poorly designed endoscopy units, inadequate and junior staffing and sub-optimal standards of patient monitoring. Their figures are quite at odds with our own experience: since opening our first endoscopy centre in 1982, we have performed more than 68 000 examinations without any deaths.

The British Society of Gastroenterology study is used to argue that the supervision provided to patients undergoing endoscopy is so substandard that if non-anaesthetists use propofol (which has the capacity to induce anaesthesia) they court disaster.3 However, all drugs used to sedate endoscopy patients can result in airway obstruction, hypotension or respiratory depression. In particular, even small doses of benzodiazepines may occasionally induce prolonged apnoea. Therefore, it is essential that endoscopy is performed only in a setting where these events can be promptly recognised and corrected, whatever drugs are used.

Are the effects of propofol sufficiently advantageous to justify the expense and any extra care in delivery? All our endoscopists had extensive prior experience of using the combination of midazolam and fentanyl, and their subjective impression was that addition of propofol markedly improved the sedation, facilitating the examination. There are many published reports relating to the use of propofol for day-only procedures, but we were unable to find a study using this combination of drugs in the manner described. There is, however, strong evidence that there are powerful synergistic effects in combinations of the three drugs used.6,7

Propofol has been shown to allow more rapid patient recovery than would occur for the same level of sedation with benzodiazepines and opiates,8,9 but it is our observation that, when used in the manner described, it has additional benefits, including:

In short, propofol, given in small doses, provides much greater flexibility in titrating the sedation to the patient's needs. This is indicated by the wide range of doses provided for both gastroscopy and colonoscopy (Box 2).

Our data demonstrate that sedation by GPs has been associated with a low incidence of adverse events. The GP sedationists do appear to have a slightly higher incidence of the minor respiratory-related adverse events, and they are significantly more likely to intervene by administering drug-reversal agents. Nevertheless, these events were managed without the need for muscle paralysis or endotracheal intubation, let alone significant morbidity or death.

The GP sedationists in our centres have demonstrated that they can manage airway obstruction and hypopnoea, as well as less common events, without any adverse patient outcome. It appears that appropriately selected and trained GPs can safely use propofol for endoscopy sedation.

Received 10 November 2000, accepted 23 July 2001

  • Anthony C Clarke1
  • Louise Chiragakis2
  • Lybus C Hillman3
  • Graham L Kaye4

  • Mugga Wara & Brindabella Endoscopy Centres, Brindabella Specialist Centre, Canberra, ACT.



Dr Bruce Shadbolt kindly performed the statistical analysis required. The authors thank all the endoscopists, anaesthetists, sedationists and nurses who cared for the patients in the study for their contribution.

Competing interests:

None declared.

  • 1. Health Insurance Commission. Medicare Benefits Schedule Group Statistics for Medicare items 30473, 30484, 30485, 30491, 32090, 32093 and 41819. July 1999 to Jun 2000. <>.
  • 2. Australian and New Zealand College of Anaesthetists and Gastroenterological Society of Australia. Sedation for endoscopy. Melbourne: ANZCA, 1997. (ANZCA Professional Document P24.) Available at: <> - no longer available, amalgamated into ANZCA Professional Document PS9.
  • 3. Bell GD, Charlton JE. Colonoscopy — is sedation necessary and is there any role for intravenous propofol? [editorial]. Endoscopy 2000; 32: 264-267.
  • 4. American Society of Anesthesiologists. New classification of physical status. Anesthesiology 1963; 24: 111.
  • 5. Quine MA, Bell GD, McCloy RF, et al. Prospective audit of upper gastrointestinal endoscopy in two regions of England: safety, staffing, and sedation methods. Gut 1995; 36: 462-467.
  • 6. Short TG, Chui PT. Propofol and midazolam act synergistically in combination. Br J Anaesth 1991; 67: 539-545.
  • 7. Ben-Shlomo I, Abd-El-Khaleim H, Ezry J, et al. Midazolam acts synergistically with fentanyl for induction of anaesthesia. Br J Anaesth 1990; 64: 45-47.
  • 8. Reimann FM, Samson U, Derad I, et al. Synergistic sedation with low-dose midazolam and propofol for colonoscopy. Endoscopy 2000; 32: 239-244.
  • 9. Wehrmann T, Kokabpick S, Lembcke B, et al. Efficacy and safety of intravenous propofol sedation during routine ERCP: a prospective, controlled trial. Gastrointest Endosc 1999; 49: 677-683.


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