Plain English Summary
Background and study aims.
Most patients undergoing major abdominal surgery are adults or elderly patients with at least one other medical condition. Propofol is the most common drug used to put people to sleep for surgery (induction of general anaesthesia) which is necessary for such procedures. Although effective, propofol can lead to undesirable side effects such as drops in blood pressure and cardiac output (the amount of blood the heart pumps in 1 minute). Vasopressors are a group of drugs that are often given to patients to raise blood pressure. When vasopressors are given, fluids (such as ringer solution) are often given at the same time to increase the amount of circulating blood in the body. In a previous study, it was shown that this is an effective way of preventing drops in blood pressure during surgery, but it does not have an effect on cardiac output. The aim of this study is to investigate the effects on the heart and circulation of giving a large dose of ringer solution while giving vasopressors to surgical patients compared to a more controlled regimen.
Who can participate?
Adult/elderly patients undergoing major high-risk abdominal surgery.
What does the study involve?
Patients are randomly allocated into two groups. Both groups are given the vasopressor phenylephrin continually while being put under general anaesthesia with propofol. Those in the first group are given a restricted quantity of liquid through a drip (Ringer solution) while they are undergoing induction of anaesthesia. Those in the second group are given a relatively large dose (bolus) of liquid during and shortly after the induction period. The heart function of both groups is measured and compared during and after the induction before surgery begins.
What are the possible benefits and risks of participating?
Patients in both groups benefit from being closely monitored with an advanced circulation monitoring system. There are no notable risks involved with participating.
Where is the study run from?
University Medical Centre Maribor (Slovenia)
When is study starting and how long is it expected to run for?
November 2016 to August 2019
Who is funding the study?
University Medical Centre Maribor (Slovenia)
Who is the main contact?
Dr Darjan Kos
ASA II-III patients undergoing large abdominal surgery, the impact of Ringer solution infusion (two different rates of infusion) with concomitant phenylephrine infusion on haemodynamic stability during bispectral (BIS) guided anaesthesia induction with propofol, a randomised controlled study
The aim of this study is to:
1. Compare the bispectral index guided induction of general anaesthesia with propofol combined with phenylephrine and restrictive regime of Ringer solution infusion and propofol combined with phenylephrine and large bolus of Ringer solution infusion
2. Investigate the impact of a larger bolus of Ringer solution on haemodynamic parameters during and after induction
National Medical Ethics Committee, 13/07/2016, ref: 67/05/16
Single-centre prospective randomized controlled trial
Primary study design
Secondary study design
Randomised controlled trial
Patient information sheet
Not available in web format, please use the contact details below to request a patient information sheet
Cardiovascular disease and abdominal surgery
In the operating theatre, participants are randomised to one of two groups using envelope randomisation.
Group 1: Participants receive fentanyl in bolus of 3mcg/kg after 1 minute of basal monitoring. Then there are additional 2 minutes of monitoring as we have to wait for fentanyl to become effective. 2 minutes after fentany (that means 3 minutes after we started monitoring) we begin with the infusion of propofol (0,5 mg/kg/min), phenylephrine (0,5 mcg/kg/min) and Ringer solution (restrictive regime meaning 1 ml/kg in following 15 minutes). The propofol is titrated to reach BIS value 60 (appropriate depth of anaesthesia) in each individual patient. After reaching BIS value 60, the infusion of propofol is stopped and the cumulative quantity measured for each individual patient. While receivnig propofol infusion we assess patient's plapebral reflex and when lost the patients are given relaxans rocuronium in bolus of 1 mg/kg. One minute after bolus of rocuronium the patients are intubated (the time from the beginig of monitoring to intubation is recorded for each patient).
Phenylephrine and Ringer solution infusion is continued at constant rate (as already mentioned) to the end of monitoring.
Group 2: Participants receive the same regime of drugs except the Ringer solution infusion is different as they are given large bolus of 10 ml/kg in 15 minutes following start of induction.
Protocol for both groups of participants includes rescue measurements also in case of haemodynamic instability:
1. Bradycardia (<40 beats per minute for more than 1 minute): bolus of atropine 0,3 mg, repeated until effective
2. Tachycardia (>100 beats per minute for more than 1 minute): bolus of fentanyl 3 mcg/kg max 3 times, then bolus of esmolol 1mg/kg
3. Hypotension (MAP<55 mmHg for more than 1 minute): additional phenylephrine boluses of 50 mcg
4. Hypertension (MAP>100 mmHg for more than 1minute): the infusion of phenylephrine will be stopped, then bolus of fentanyl 3mcg/kg max 3 times
Participants have their cardiac output, stroke volume and mean arterial pressure measured using a LiDCOrapid monitor at baseline and for 15 minutes during the induction of anaesthesia.
Primary outcome measure
1. Cardiac output is measured using a LiDCOrapid monitor at baseline and for 15 minutes during the induction of anaesthesia
2. Stroke volume is measured using a LiDCOrapid monitor at baseline and for 15 minutes during the induction of anaesthesia
3. Mean arterial pressure is measured using a LiDCOrapid monitor at baseline and for 15 minutes during the induction of anaesthesia
Secondary outcome measures
1. Heart rate is measured using a LiDCOrapid monitor at baseline and for 15 minutes during the induction of anaesthesia
2. Systemic vascular resistance is measured using a LiDCOrapid monitor at baseline and for 15 minutes during the induction of anaesthesia
3. Bispectral index is measured using a LiDCOrapid monitor at baseline and for 15 minutes during the induction of anaesthesia
4. Dose of propofol is measured at the end of induction (the cumulative dose is given on the perfusor screen)
5. Time from start of anaesthesia induction to laryngoscopy and intubation is measured for each patient using timer on the screen of anaeshesia machine
6. Potential rescue management is recorded for each patient at the end of induction
7. Doses of drugs needed is calculated at the end of induction for each patient
Overall trial start date
Overall trial end date
Reason abandoned (if study stopped)
Participant inclusion criteria
1. Aged 50 years and over
2. ASA II-III
3. Patients scheduled for major abdominal surgery
Target number of participants
Participant exclusion criteria
1. Heart failure (known ejection fraction less than 30%)
2. Manifest liver disease
3. Kidney disease (serum creatinine more than 120 mmol/L)
4. BMI more than 30
5. Anticipated difficult intubation (Mallampati score 3 and 4)
6. Drug abuse (including alcohol)
7. Chronic use of benzodiazepines, opioids or other psychotropic substances
Recruitment start date
Recruitment end date
Countries of recruitment
Trial participating centre
University Medical Centre Maribor
Ob železnici 30
University Medical Centre Maribor
Funding Body Type
Funding Body Subtype
Results and Publications
Publication and dissemination plan
Planned publication in a high-impact peer reviewed journal.
IPD Sharing plan:
The datasets generated and analysed during the current study will be included in the subsequent results publication.
Intention to publish date
Participant level data
Basic results (scientific)