Retinal Detachment
Conditions
Keywords
sedation for vitreoretinal surgery
Brief summary
The investigators would like to determine if using Dexmedetomidine alone or in a reduced dose can prevent or reduce the incidence of adverse effects, while providing adequate sedation, and respiratory stability as compared to propofol.
Detailed description
Alpha2 adrenergic receptor agonist have been used increasingly as a new armamentarium to provide sedative/hypnotic, analgesic, anxiolytic and sympatholytic effects in the perioperative settings. Dexmedetomidine, a selective and specific alpha2- adrenoceptor agonist has unique properties that makes it an almost ideal sedative drug for monitored anesthesia care in procedures under local or regional block. Unlike other drugs use for sedation, dexmedetomidine induces sedation that is similar to natural sleep (readily arousable) without causing respiratory depression. It attenuates the stress-induced sympathoadrenal response seen with laryngoscopy and intubation. It has anesthetic and opioid sparing effects, hence it may be a useful adjunct to general anesthesia and monitored anesthesia care in patients susceptible to narcotic induced respiratory depression. Another unique property of dexmedetomidine is that its sedative effect is reversible with Atipamezole. A previous study wherein dexmedetomidine has been used in procedures under local and regional block had shown that it provides effective sedation and better operating condition without significant respiratory depression. As a supplement to general anesthesia, it has been shown to provide stable hemodynamics. However, it is associated with some adverse events such as hypertension, hypotension and bradycardia, these commonly occur during bolus administration of the recommended dose of 1ug/kg. Post-operatively it can cause nausea and vomiting. Vitreoretinal surgery requires either an injection of local anesthetic within the muscle cone (retrobulbar block),or into the periorbital space (peribulbar block). This can be done individually or in combination. This surgery can also be done under a safer technique of retrobulbar block that is given using a sub-tenon's approach through a snip peritomy; a blunt cannula can be used with this technique mitigating the complications of retrobulbar hemorrhage or inadvertent injection into the optic nerve sheath or perforation of the globe using a sharp needle. The anesthetic goal is to provide an immobile and uncongested operative field. Hemodynamic stability of the patient is also important since some patients that require this procedure are elderly with co-morbid conditions such as hypertension, diabetes mellitus and Coronary Artery Disease (CAD). In our study we would like to investigate if Dexmedetomidine alone and in a reduced dose can prevent or reduce the incidence of adverse effects, provide hemodynamic and respiratory stability, provide adequate sedation with patient and surgeon satisfaction and compare it with Propofol. Objectives: Primary: 1. Adequate sedation 2. Hemodynamic and respiratory stability intraoperatively Secondary: 1. surgeon satisfaction 2. Time to achieved street fitness status 3. subject satisfaction 4. Hemodynamic stability in PACU
Interventions
bolus of 0.5ug/kg intravenously over a period of 10-15 minutes, followed by an infusion of 0.2-0.7ug/kg/hr of drug
propofol 1mg/kg intravenously as a bolus followed by 25-100ug/kg/min
Sponsors
Study design
Eligibility
Inclusion criteria
* American Society of Anesthesiologists rating of I-III * good renal and liver function
Exclusion criteria
* renal and hepatic insufficiency * uncontrolled diabetes * uncontrolled hypertension * severe cardiac disease Class III or IV * heart blocks * chronic use of sedatives, narcotics, alcohol or illicit drugs * allergy to either propofol or dexmedetomidine * pregnancy or inability to tolerate technique of the study drugs
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Adequate Sedation Via Bispectral Index Score (BIS)and University of Michigan Sedation Scale (UMSS) | Intraoperative up to 120 min | Bispectral Index Score measurement uses processed electroencephalogram signals to measure sedation depth of a scale from 0-100 (0=coma; 40-60=general anesthesia;60-90 sedated;100=awake) University of Michigan Sedation Scale (1-4) is an observational scale that quantifies sedation.1=normal response to verbal stimuli, 2=conscious sedation, responsive to tactile stimuli, 3= deeply sedated responsive to repeated or painful stimuli, 4=general anesthesia: not arousable. |
| Intraoperative Hemodynamic Stability | Intraoperative up to 120 min | systolic and diastolic blood pressure was recorded at 5 minute intervals up to 120 min and were averaged per study arm |
| Intraoperative Respiratory Stability | Intraoperative up to 120 min | respiratory rate data were recorded at 5 minutes intervals throughout the surgical procedure up to 120 mins for both groups and averaged per study arm |
| Intraoperative Heart Rate Stability | Intraoperative up to 120 min | Heart rate recorded at 5 minute intervals during surgery up to 120 min and averaged per study arm |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Post Operative Hemodynamic Stability | 2 hours in PACU | blood pressure documented at 30 minute intervals in PACU up to 120 min |
| Time to Achieve Street Fitness | for 2 hours post-operatively in Post Anesthesia Care unit | Subjects will be kept in the Post Anesthesia Care Unit (PACU) for a period of 2 hours. However it will be documented as to when, in the opinion of the PACU staff, the subject has met the criteria for discharge. |
| Hemodynamic Stability Post Operatively in PACU | PACU to 2 hours post op | heart rate recorded at 30 min intervals in PACU up to 120 min |
| Surgeon Satisfaction for Adequate Sedation | at 10 minutes into the procedure | 1=very poor, 2=poor,3=fair, 4=good, 5=excellent |
| Surgeon Satisfaction for Adequate Sedation at Completion of Procedure | immediately following the completion of the procedure up to one hour | surgeon satisfaction graded on numerical scale 1=very poor. 2=poor, 3=fair 4=good, 5=excellent |
| Patient Satisfaction | measured prior to discharge up to 2 hours | 1=very poor, 2=poor, 3=fair, 4=very good, 5=excellent |
Countries
United States
Participant flow
Recruitment details
Subjects were recruited the morning of surgery in the Same Day Surgery Suite
Pre-assignment details
One subject withdrew consent prior to group assignment. One subject surgery was cancelled
Participants by arm
| Arm | Count |
|---|---|
| Propofol propofol 1mg/kg as a bolus intravenously followed by an infusion of 25-100 ug/kg/min
propofol: propofol 1mg/kg intravenously as a bolus followed by 25-100ug/kg/min | 39 |
| Dexmedetomidine Infusion Subject will receive a bolus of0.5ug/kg intravenously over a period of 10-15 minutes, followed by an infusion of 0.2-0.7ug/kg/hr of drug.
Dexmedetomidine infusion: bolus of 0.5ug/kg intravenously over a period of 10-15 minutes, followed by an infusion of 0.2-0.7ug/kg/hr of drug | 37 |
| Total | 76 |
Withdrawals & dropouts
| Period | Reason | FG000 | FG001 |
|---|---|---|---|
| Overall Study | surgery cancelled | 0 | 1 |
Baseline characteristics
| Characteristic | Propofol | Dexmedetomidine Infusion | Total |
|---|---|---|---|
| Age, Continuous | 40 years | 52 years | 46 years |
| Sex: Female, Male Female | 11 Participants | 12 Participants | 23 Participants |
| Sex: Female, Male Male | 28 Participants | 25 Participants | 53 Participants |
| total participants | 39 participants | 37 participants | 76 participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — |
| other Total, other adverse events | 0 / 39 | 0 / 37 |
| serious Total, serious adverse events | 0 / 39 | 1 / 37 |
Outcome results
Adequate Sedation Via Bispectral Index Score (BIS)and University of Michigan Sedation Scale (UMSS)
Bispectral Index Score measurement uses processed electroencephalogram signals to measure sedation depth of a scale from 0-100 (0=coma; 40-60=general anesthesia;60-90 sedated;100=awake) University of Michigan Sedation Scale (1-4) is an observational scale that quantifies sedation.1=normal response to verbal stimuli, 2=conscious sedation, responsive to tactile stimuli, 3= deeply sedated responsive to repeated or painful stimuli, 4=general anesthesia: not arousable.
Time frame: Intraoperative up to 120 min
| Arm | Measure | Value (MEAN) |
|---|---|---|
| BIS Scores in Propofol Infusion Group | Adequate Sedation Via Bispectral Index Score (BIS)and University of Michigan Sedation Scale (UMSS) | 84.8 units on a scale |
| BIS Scores in Dexmedetomidine Infusion Group | Adequate Sedation Via Bispectral Index Score (BIS)and University of Michigan Sedation Scale (UMSS) | 88 units on a scale |
| UMSS Scores in Propofol Infusion Group | Adequate Sedation Via Bispectral Index Score (BIS)and University of Michigan Sedation Scale (UMSS) | .90 units on a scale |
| UMSS in Dexmedetomidine Infusion Group | Adequate Sedation Via Bispectral Index Score (BIS)and University of Michigan Sedation Scale (UMSS) | .94 units on a scale |
Intraoperative Heart Rate Stability
Heart rate recorded at 5 minute intervals during surgery up to 120 min and averaged per study arm
Time frame: Intraoperative up to 120 min
| Arm | Measure | Value (MEAN) |
|---|---|---|
| BIS Scores in Propofol Infusion Group | Intraoperative Heart Rate Stability | 71 beats per minute |
| BIS Scores in Dexmedetomidine Infusion Group | Intraoperative Heart Rate Stability | 64 beats per minute |
Intraoperative Hemodynamic Stability
systolic and diastolic blood pressure was recorded at 5 minute intervals up to 120 min and were averaged per study arm
Time frame: Intraoperative up to 120 min
| Arm | Measure | Value (MEAN) |
|---|---|---|
| BIS Scores in Propofol Infusion Group | Intraoperative Hemodynamic Stability | 124.9 mm/Hg |
| BIS Scores in Dexmedetomidine Infusion Group | Intraoperative Hemodynamic Stability | 114.6 mm/Hg |
| UMSS Scores in Propofol Infusion Group | Intraoperative Hemodynamic Stability | 73.6 mm/Hg |
| UMSS in Dexmedetomidine Infusion Group | Intraoperative Hemodynamic Stability | 66.2 mm/Hg |
Intraoperative Respiratory Stability
respiratory rate data were recorded at 5 minutes intervals throughout the surgical procedure up to 120 mins for both groups and averaged per study arm
Time frame: Intraoperative up to 120 min
| Arm | Measure | Value (MEAN) |
|---|---|---|
| BIS Scores in Propofol Infusion Group | Intraoperative Respiratory Stability | 17 breaths per minute |
| BIS Scores in Dexmedetomidine Infusion Group | Intraoperative Respiratory Stability | 12 breaths per minute |
Hemodynamic Stability Post Operatively in PACU
heart rate recorded at 30 min intervals in PACU up to 120 min
Time frame: PACU to 2 hours post op
| Arm | Measure | Value (MEAN) |
|---|---|---|
| BIS Scores in Propofol Infusion Group | Hemodynamic Stability Post Operatively in PACU | 74.1 beats per minute |
| BIS Scores in Dexmedetomidine Infusion Group | Hemodynamic Stability Post Operatively in PACU | 72 beats per minute |
Patient Satisfaction
1=very poor, 2=poor, 3=fair, 4=very good, 5=excellent
Time frame: measured prior to discharge up to 2 hours
| Arm | Measure | Value (MEAN) |
|---|---|---|
| BIS Scores in Propofol Infusion Group | Patient Satisfaction | 4.61 units on a scale |
| BIS Scores in Dexmedetomidine Infusion Group | Patient Satisfaction | 4.43 units on a scale |
Post Operative Hemodynamic Stability
blood pressure documented at 30 minute intervals in PACU up to 120 min
Time frame: 2 hours in PACU
| Arm | Measure | Value (MEAN) |
|---|---|---|
| BIS Scores in Propofol Infusion Group | Post Operative Hemodynamic Stability | 124.9 mmHg |
| BIS Scores in Dexmedetomidine Infusion Group | Post Operative Hemodynamic Stability | 114.6 mmHg |
| UMSS Scores in Propofol Infusion Group | Post Operative Hemodynamic Stability | 73.6 mmHg |
| UMSS in Dexmedetomidine Infusion Group | Post Operative Hemodynamic Stability | 66.2 mmHg |
Surgeon Satisfaction for Adequate Sedation
1=very poor, 2=poor,3=fair, 4=good, 5=excellent
Time frame: at 10 minutes into the procedure
| Arm | Measure | Value (MEAN) |
|---|---|---|
| BIS Scores in Propofol Infusion Group | Surgeon Satisfaction for Adequate Sedation | 4.62 units on a scale |
| BIS Scores in Dexmedetomidine Infusion Group | Surgeon Satisfaction for Adequate Sedation | 4.97 units on a scale |
Surgeon Satisfaction for Adequate Sedation at Completion of Procedure
surgeon satisfaction graded on numerical scale 1=very poor. 2=poor, 3=fair 4=good, 5=excellent
Time frame: immediately following the completion of the procedure up to one hour
| Arm | Measure | Value (MEAN) |
|---|---|---|
| BIS Scores in Propofol Infusion Group | Surgeon Satisfaction for Adequate Sedation at Completion of Procedure | 4.77 units on a scale |
| BIS Scores in Dexmedetomidine Infusion Group | Surgeon Satisfaction for Adequate Sedation at Completion of Procedure | 4.89 units on a scale |
Time to Achieve Street Fitness
Subjects will be kept in the Post Anesthesia Care Unit (PACU) for a period of 2 hours. However it will be documented as to when, in the opinion of the PACU staff, the subject has met the criteria for discharge.
Time frame: for 2 hours post-operatively in Post Anesthesia Care unit
Population: Subjects meet criteria for discharge based upon the assessment from a professional independent of the study
| Arm | Measure | Value (MEAN) |
|---|---|---|
| BIS Scores in Propofol Infusion Group | Time to Achieve Street Fitness | 81 minutes |
| BIS Scores in Dexmedetomidine Infusion Group | Time to Achieve Street Fitness | 85 minutes |