Robotic Thyroidectomy
Conditions
Brief summary
Percutaneous tunnelling (hydrodissection) in the neck and anterior chest in patients undergoing robotic thyroidectomy leads to significant haemodynamic responses such as increases in blood pressure and heart rate. The investigators evaluated whether a single preoperative dexmedetomidine injection attenuated the haemodynamic responses to hydrodissection by reducing the half-maximal effective concentration (EC50) of remifentanil needed to maintain haemodynamic stability during hydrodissection.
Detailed description
Dexmedetomidine (DXM) is a recently released and approved alpha 2 agonist with a relatively high ratio of α2/α1-activity and an almost fourfold shorter half-life than clonidine.It's sympatholytic, sedative, and analgesic properties makes DXM a useful anaesthetic adjuvant for general anaesthesia. While there are some reports of the beneficial effects of DXM on anaesthetic requirements and haemodynamic responses to endotracheal intubation, the effect of a single preoperative injection of DXM in terms of attenuating haemodymanic responses to surgical stimulation in robot-assisted thyroidectomy is unknown. When a robotic thyroidectomy using the bilateral axillary breast approach (BABA) technique is performed, subcutaneous tunnelling in the neck and anterior chest, which is defined as hydrodissection, is mandatory. Unfortunately, the procedure leads to significant haemodynamic responses, such as increases in blood pressure and heart rate. We hypothesised that preoperative DXM administration would attenuate the haemodynamic responses to hydrodissection. This study was designed to evaluate the effects of a single preoperative administration of DXM on haemodynamic responses to hydrodissection in robotic thyroidectomy by comparing the half-maximal effective concentration (EC50) of remifentanil needed to maintain haemodynamic stability during hydrodissection between DXM and control groups. We also investigated the effects of preoperative DXM administration on total doses of remifentanil and propofol administered intraoperatively.
Interventions
DRUGDXM + Propofol
After induction as mentioned at 'arm description', the effect-site propofol concentration was fixed at 5.0 μg mL-1 at the time of diluted epinephrine injection and was unchanged during the entire hydrodissection period in all patients. The first patients received effect-site concentrations of remifentanil of 4 ng mL -1, respectively. The EC50 of remifentanil for stable hydrodissection was determined by a modification of Dixon's up-and-down method.If the response was success (SBP during the entire hydrodissection period being ±20% from baseline), the next target concentration of remifentanil was decreased by a step of 0.5 ng mL -1. If the response was fail(SBP \> ±20% from baseline), the target concentration was increased by 0.5 ng mL-1.
DRUGSaline + Propofol
All procedure would be same in DXM+Propofol group except saline loading rather than DXM loading before induction.
Sponsors
Seoul National University Hospital
Study design
Allocation
RANDOMIZED
Intervention model
SINGLE_GROUP
Primary purpose
SUPPORTIVE_CARE
Masking
TRIPLE (Caregiver, Investigator, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
20 Years to 65 Years
Healthy volunteers
No
Inclusion criteria
* ASA physical status I-II patientsscheduled for general anaesthesia for robotic thyroidectomy
Exclusion criteria
* Patients with an allergy to α2-adrenergic agonists or propofol * Patients with current antihypertensive medication * Patients with heart block \> 1 degree * Patients with severe cardiorespiratory dysfunction * Patients with history of alcohol or drug abuse * Patients who had received an opioid analgesic medication within the previous 24-h period before the operation
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Remifentanil EC50 during hydrodissection | at the time point of hydrodissection intraopeartively | Compare remifentanil EC50 for maintaining haemodynamic stability during hydrodissection between 2 groups. The EC50 of remifentanil for maintaining haemodynamic stability was determined by a modification of Dixon's up-and-down method.If the response was success (SBP during the entire hydrodissection period being ±20% from baseline), the next target concentration of remifentanil was decreased by a step of 0.5 ng mL -1. If the response was fail(SBP \> ±20% from baseline), the target concentration was increased by 0.5 ng mL-1. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Total doses of remifentanil & propofol administration | Intraoperatively | Compare total doses of remifentanil and propofol administered intraoperatively between 2 groups. |
Countries
South Korea
Outcome results
None listed