An interventional study of Standard-dose balanced propofol analgosedation and Dose-sparing balanced propofol analgosedation in Colonoscopy and Sedation and Analgesia, sponsored by University of Split, School of Medicine. Completed at 2 sites in Croatia. Open to participants aged 18 Years to 65 Years. Per ClinicalTrials.gov, last updated 2026-10-21.
Sponsored by University of Split, School of Medicine · Not applicable, Interventional, and Supportive care
This randomized controlled trial compared two balanced propofol analgosedation strategies in adults undergoing elective colonoscopy. Participants were randomized to either a standard-dose protocol using an initial propofol dose of 1.0 mg/kg or a structured dose-sparing protocol using an initial propofol dose of 0.5 mg/kg. Both protocols included midazolam and fentanyl. The standard-dose protocol was anesthesiologist-guided, whereas the dose-sparing protocol was administered by a gastroenterologist trained in advanced life support and airway management, with an anesthesia technician present and an anesthesiologist immediately available if required. The primary outcomes were patient satisfaction and clinically relevant respiratory adverse events, with apnea lasting more than 30 seconds as the principal respiratory safety endpoint. Secondary outcomes included propofol exposure, recovery, procedural performance, cardiovascular adverse events, depth of sedation and nociception-related indices, and endoscopist satisfaction.
This randomized controlled trial evaluated two protocol-based strategies for balanced propofol analgosedation in adults undergoing elective colonoscopy. Eligible participants were 18-65 years of age with American Society of Anesthesiologists (ASA) physical status I-III. Participants were randomized in an intended 1:1 ratio to either a standard-dose balanced propofol protocol or a structured dose-sparing protocol.
Both groups received intravenous midazolam, fentanyl, and propofol. Midazolam was administered at 0.05 mg/kg, up to a maximum dose of 5 mg, followed by fentanyl 0.001 mg/kg. The initial propofol dose was 1.0 mg/kg in the standard-dose group and 0.5 mg/kg in the dose-sparing group. Additional propofol boluses were administered according to clinical need and patient response during the procedure.
In the standard-dose group, sedation was guided by an anaesthesiologist. In the dose-sparing group, sedation was guided by a gastroenterologist trained in advanced life support and airway management, with an anaesthesia technician present and an anaesthesiologist immediately available if required. Because the sedation provider and propofol dosing strategy differed together between study groups, the trial was designed to compare the complete protocol-based care strategies rather than to determine the independent effect of provider specialty.
Participants underwent continuous cardiorespiratory monitoring, including pulse oximetry, heart rate, non-invasive blood pressure, and capnography with end-tidal carbon dioxide monitoring. Sedation depth was additionally assessed using clinical sedation scoring and processed electroencephalographic indices.
The primary outcomes were patient satisfaction and clinically relevant respiratory adverse events. Clinically relevant apnea, defined as an apnea episode lasting more than 30 seconds, was analyzed as the principal respiratory safety endpoint. Secondary outcomes included total propofol exposure, additional propofol requirements, early and total recovery time, procedural performance, cardiovascular adverse events, depth of sedation and nociception-related indices, endoscopist satisfaction, and patient-reported anxiety and pain. Recovery was assessed using standard post-anaesthesia recovery criteria.
The study was designed to determine whether a structured dose-sparing balanced propofol strategy could reduce sedative drug exposure and respiratory adverse events while maintaining adequate procedural conditions, recovery, and patient and endoscopist satisfaction.
University of Split, School of Medicine is the lead sponsor of 51 studies on the registry; 17 are open to participants now.
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Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
ASA physical status
The anaesthetists’ scale of health before surgery: I is healthy, II has a mild illness that is under control, III a severe one, IV a severe illness that is a constant threat to life. V and VI are used for the critically ill and for organ donors.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraindication
A reason a treatment, test or procedure should not be given to a particular person, such as an allergy, another illness or a medicine they take.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Intravenous midazolam 0.05 mg/kg (maximum 5 mg), followed by fentanyl 0.001 mg/kg and an initial propofol bolus of 1.0 mg/kg. Additional propofol boluses of 10-30 mg were administered according to clinical need. Sedation and monitoring were guided by an anesthesiologist with an anesthesia technician present.
Drug: Standard-dose balanced propofol analgosedation
Intravenous midazolam 0.05 mg/kg (maximum 5 mg), followed by fentanyl 0.001 mg/kg and an initial propofol bolus of 0.5 mg/kg. Additional propofol boluses of 10-30 mg were administered according to clinical need. Sedation and monitoring were guided by a gastroenterologist trained in advanced life support and airway management, with an anesthesia technician present and an anesthesiologist immediately available if required.
Drug: Dose-sparing balanced propofol analgosedation
Intravenous balanced analgosedation with midazolam, fentanyl, and propofol. Midazolam was administered at 0.05 mg/kg, up to a maximum dose of 5 mg. Fentanyl 0.001 mg/kg was administered 3 minutes later, followed by an initial propofol bolus of 1.0 mg/kg at minute 5. Additional propofol boluses of 10-30 mg were administered according to clinical need and patient response during colonoscopy. Sedation and monitoring were guided by an anaesthesiologist with an anaesthesia technician present.
Also known as: Standard-dose balanced propofol sedation, Anaesthesiologist-guided balanced propofol analgosedation
Intravenous balanced analgosedation with midazolam, fentanyl, and propofol. Midazolam was administered at 0.05 mg/kg, up to a maximum dose of 5 mg. Fentanyl 0.001 mg/kg was administered 3 minutes later, followed by an initial propofol bolus of 0.5 mg/kg at minute 5. Additional propofol boluses of 10-30 mg were administered according to clinical need and patient response during colonoscopy. Sedation and monitoring were guided by a gastroenterologist trained in advanced life support and airway management, with an anaesthesia technician present and an anaesthesiologist immediately available if required.
Also known as: Dose-sparing balanced propofol sedation, Gastroenterologist-guided balanced propofol analgosedation
Patient satisfaction
Patient satisfaction was assessed using a study-specific four-item questionnaire. Two items assessed satisfaction with the colonoscopy procedure and satisfaction with analgosedation using separate 11-point numerical rating scales ranging from 0 (completely dissatisfied) to 10 (extremely satisfied). Two additional binary items assessed whether the participant would recommend the same approach to relatives or friends and whether the participant would agree to undergo colonoscopy using the same approach again.
Time frame: At completion of post-procedural recovery on the day of colonoscopy.
Incidence of clinically relevant respiratory adverse events
Incidence of protocol-defined respiratory adverse events, reported by event type. Respiratory events included apnea lasting more than 30 seconds, oxygen saturation below 90%, respiratory rate below 10 or above 20 breaths per minute, end-tidal CO2 below 35 mmHg, and the need for airway-opening interventions. Apnea lasting more than 30 seconds was analyzed as the principal respiratory safety endpoint.
Time frame: From administration of sedation through completion of monitored post-procedural recovery on the day of colonoscopy.
Total propofol dose
Total cumulative dose of propofol administered during the colonoscopy, expressed in milligrams.
Time frame: From initial propofol administration until completion of the colonoscopy.
Number of additional propofol boluses
Number of additional propofol boluses administered after the initial protocol-defined propofol dose.
Time frame: From initial propofol administration until completion of the colonoscopy.
Cumulative additional propofol dose
Total cumulative dose of additional propofol administered after the initial protocol-defined propofol dose, expressed in milligrams.
Time frame: From initial propofol administration until completion of the colonoscopy.
Early recovery time
Time from completion of the colonoscopy until achievement of the predefined early post-anaesthesia recovery criterion based on the Modified Aldrete Score.
Time frame: From completion of colonoscopy through the early post-procedural recovery period on the day of the procedure.
Total recovery time
Time from completion of the colonoscopy until achievement of predefined discharge-readiness criteria based on post-anaesthesia recovery assessment, including the Post-Anesthesia Discharge Scoring System (PADSS).
Time frame: From completion of colonoscopy until completion of monitored post-procedural recovery on the day of the procedure.
Cecal intubation rate
Proportion of colonoscopies in which the colonoscope was successfully advanced to the cecum.
Time frame: During colonoscopy.
Cecal intubation time
Time from insertion of the colonoscope until successful intubation of the cecum.
Time frame: During the index colonoscopy.
Colonoscope withdrawal time
Time from initiation of colonoscope withdrawal from the cecum until completion of the examination.
Time frame: During colonoscopy.
Adenoma detection rate
Proportion of participants in whom at least one colorectal adenoma was detected during the index colonoscopy and confirmed by histopathological examination.
Time frame: During the index colonoscopy, with histopathological confirmation following the procedure.
Colorectal cancer detection rate
Proportion of participants in whom colorectal cancer was detected during the index colonoscopy and confirmed by histopathological examination.
Time frame: During the index colonoscopy, with histopathological confirmation following the procedure.
Endoscopist satisfaction
Endoscopist-reported satisfaction with procedural conditions assessed using a 11-point numerical rating scale, with higher scores indicating greater satisfaction.
Time frame: Immediately after completion of colonoscopy.
Incidence of clinically relevant cardiovascular adverse events
Incidence of protocol-defined cardiovascular adverse events, reported by event type, including systolic blood pressure below 90 mmHg, heart rate below 50 or above 110 beats per minute, and clinically relevant arrhythmias.
Time frame: From administration of sedation through completion of monitored post-procedural recovery on the day of colonoscopy.
Depth of sedation assessed by qCON
Depth of sedation assessed using the qCON index derived from processed electroencephalographic monitoring. qCON values range from 0 to 99, with lower values indicating deeper levels of sedation or hypnosis.
Time frame: From baseline before sedation through completion of the colonoscopy, assessed at predefined intervals.
Nociception-related response assessed by qNOX
Nociception-related response assessed using the qNOX index derived from processed electroencephalographic monitoring. qNOX values range from 0 to 99, with lower values indicating a lower probability of response to noxious stimulation.
Time frame: From baseline before sedation through completion of the colonoscopy, assessed at predefined intervals.
Clinical depth of sedation
Clinical depth of sedation assessed using the Modified Wilson Sedation Scale at predefined intervals during the procedure.
Time frame: From administration of sedation through completion of the colonoscopy.
Patient anxiety assessed using the Endler Multidimensional Anxiety Scales (EMAS)
Patient anxiety was assessed using the Endler Multidimensional Anxiety Scales (EMAS). Trait anxiety was assessed using the EMAS-T during the initial study interview. State anxiety was assessed using the EMAS-S immediately before colonoscopy and again 48-72 hours after the procedure.
Time frame: At the initial study interview, immediately before colonoscopy, and 48-72 hours after colonoscopy.
Patient pain assessed using the Brief Pain Inventory (BPI)
Patient-reported pain was assessed using the Brief Pain Inventory (BPI). The long form was completed during the initial study interview, while the short form was completed immediately before colonoscopy and again 48-72 hours after the procedure. BPI measures pain severity and pain-related interference, with higher scores indicating greater pain severity or interference.
Time frame: At the initial study interview, immediately before colonoscopy, and 48-72 hours after colonoscopy.
Plan to share: Yes — Deidentified individual participant data that underlie the results reported in the primary publication will be made available to qualified researchers upon reasonable request, subject to approval by the study investigators and applicable institutional, ethical, and data-protection requirements.
Supporting information: Study protocol
Time frame: Data will be available beginning 6 months after publication of the primary study results and for 5 years thereafter.
Access criteria: Requests should include a scientifically justified research proposal describing the objectives, planned analyses, and intended use of the data. Requests will be reviewed by the study investigators for scientific validity, feasibility, participant confidentiality, and compliance with applicable ethical and data-protection requirements. Deidentified data will be provided only after approval of the request and, where required, execution of an appropriate data-use agreement.
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Ran from Jun 2022 to primary completion in Feb 2024, 19 months.
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This study is completed, as verified in Oct 2026. You cannot join it, but the record below documents what was studied.
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Agnosia
University of Split, School of Medicine