Impact of Propofol Reduction in Anesthesia Induction

Phase 4

Completed

Conditions: Anesthesia
Propofol Adverse Reaction

Interventions: Drug: Propofol Injection

Registration Number: NCT04194151

Lead Sponsor: Hospital Central de la Defensa Gómez Ulla

Brief Summary: Objective: Determine if, by reducing the dose of propofol and increasing the time elapsed between fentanyl and propofol administration, hemodynamic response is improved.

Methods: Patients were randomized into time groups (2 and 1 minute) and each subdivided into dose groups (1, 1.5 and 2 mg kg-1) obtaining six time-dose groups. After receiving 2 μg kg-1 of fentanyl, propofol was administered after the predetermined time. Time to hypnosis (BIS\<60) and hemodynamic parameters at pre-induction, pre-intubation and postintubation were registered.

Detailed Description: A minimum of 162 patients were required, considering an expected Mean Difference of 5 with expected Standard Deviation of 22, confidence level of 95% and power of 80%. Estimating a possible loss of 15%, it was raised to 192. Consecutive identification numbers were assigned and the sample was randomized in six groups of 32 patients according to time and dose of propofol.

Pre-oxygenation was performed until the expired oxygen fraction exceeded 80% and 2 µg/kg of intravenous fentanyl were administered. Depending on the study group, 1 or 2 minutes were allowed to pass and 1, 1.5 or 2 mg/kg of propofol were supplied (prior administration of intravenous lidocaine 0.5 mg/kg). The time in which the BIS dropped below 60 was recorded. If it did not reach that level after two minutes or when it exceeded it but then rose above 60 again, an extra dose of propofol of 0.5 mg/kg was administered. Muscle relaxation was performed with rocuronium 0.6 mg/kg. The patient was manually ventilated until endotracheal intubation was performed by the same experienced anaesthesiologist and connected to mechanical ventilation.

Data were collected manually. Statistical analysis was performed using SPSS ver. 22. Inferential statistics were performed using t-test for quantitative variables, chi-square for qualitative and ANOVA for qualitative and quantitative comparisons. Non-parametric statistical tests were used when necessary. Confidence intervals were estimated at a level of 95% and a P value of \<.05 was considered statistically significant.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 192

Inclusion Criteria

Adults who required general anesthesia
General anesthesia with endotracheal intubation (no supraglottic devices)
Signed informed consent
Non-cardiac surgery
Same anesthesiologist

Exclusion Criteria

Hemodynamic instability (systolic BP < 90 mmHg with clinical signs of low cardiac output: impaired consciousness, diuresis <0.5 ml/kg/h, central venous saturation <60% with normal arterial saturation or lactate >3 mmol/l)
Increased risk of bronchoaspiration (absence of fasting, stomach retention, intestinal obstruction, pregnancy, etc.)
Suspected difficult airway
Known allergy to anesthetic drugs

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
2 minute - 2 mg/kg group	Propofol Injection	2 mcg/kg of fentanyl administrated intravenously. wait for 2 minutes to inject 2 mg/kg of propofol
1 minute - 1,5 mg/kg group	Propofol Injection	2 mcg/kg of fentanyl administrated intravenously. wait for 1 minute to inject 1,5 mg/kg of propofol
2 minute - 1,5 mg/kg group	Propofol Injection	2 mcg/kg of fentanyl administrated intravenously. wait for 2 minutes to inject 1,5 mg/kg of propofol
2 minute - 1 mg/kg group	Propofol Injection	2 mcg/kg of fentanyl administrated intravenously. wait for 2 minutes to inject 1 mg/kg of propofol
1 minute - 2 mg/kg group	Propofol Injection	2 mcg/kg of fentanyl administrated intravenously. wait for 1 minute to inject 2 mg/kg of propofol
1 minute - 1 mg/kg group	Propofol Injection	2 mcg/kg of fentanyl administrated intravenously. wait for 1 minute to inject 1 mg/kg of propofol

Primary Outcome Measures

Name	Time	Method
Systolic Blood Pressure Variation	Baseline before fentanyl administration, pre-intubation after propofol and bispectral index<60 and postintubation 15 seconds after endotracheal tube positioned	Non-invasive systolic blood pressure change (%) at baseline, pre-intubation and postintubation. Positive results mean percentage reduction in SBP between the studied moments. Negative results mean percentage increase in SBP between the studied moments.
Heart Rate Variation	Baseline before fentanyl administration, pre-intubation after propofol and bispectral index<60 and postintubation 15 seconds after endotracheal tube positioned	Heart rate change (%) registered at baseline, pre-intubation and postintubation. Positive results mean percentage reduction in HR between the studied moments. Negative results mean percentage increase in HR between the studied moments.
Systolic Blood Pressure Variation in Elderly (>55y)	Baseline before fentanyl administration, pre-intubation after propofol and bispectral index<60 and postintubation 15 seconds after endotracheal tube positioned	Non-invasive SBP change (%) in patients \> 55 years at baseline, pre-intubation and postintubation. Positive results mean percentage reduction in SBP between the studied moments. Negative results mean percentage increase in SBP between the studied moments.

Secondary Outcome Measures

Name	Time	Method
Number of Patients Who Needed Vasoactive Drug	1 minute after intubation	Patients who suffered SPB reduction \> 30% or SPB \< 90mmHg, receive vasoactive drugs
Time to Hypnosis	After administration of propofol, time is measured in seconds until BIS values are less than 60	Bispectral index (BIS)\<60 meaning "general anesthesia", BIS\>60 meaning mild/moderate sedation. We measure the time until patient reachs hypnosis