Preop Dexmedetomidine Attenuates Haemodynamic Responses to Hydrodissection (DXM_Hydro)

Seoul National University

Status and phase: Completed; Phase 4

Conditions: Robotic Thyroidectomy

Treatments: Drug: DXM + Propofol; Drug: Saline + Propofol

Study type: Interventional

Funder types: Other

Identifiers

NCT02102139

DXM_Hydrodissection

Details and patient eligibility

About

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.

Full 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.

Enrollment: 41 patients

Sex: All

Ages: 20 to 65 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Single Group Assignment

Masking: Triple Blind

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41 participants in 2 patient groups, including a placebo group

DXM + Propofol

Experimental group

Description:

DXM (1 µg kg -1) was loaded intravenously for 10 min before anaesthesia induction.During DXM loading, the depth of anaesthesia was monitored using a bispectral index (BIS) monitor. Electrocardiogram, heart rate, pulse oximetry, and non-invasive arterial blood pressure were monitored at 2-min intervals. Anaesthesia was induced with propofol 3.5 μg mL 1 and remifentanil 5 ng mL 1 at an effect site concentration using a target-controlled infusion (TCI) device. Anaesthesia was maintained with propofol and remifentanil continuous infusions. During surgery except the study period, propofol and remifentanil doses were adjusted to maintain BIS value of 40-60 and systolic blood pressure (SBP) within ±20% from baseline respectively.

Treatment:

Drug: DXM + Propofol

Saline + Propofol

Placebo Comparator group

Description:

Saline (1 µg kg -1) was loaded intravenously for 10 min before anaesthesia induction.During saline loading, the depth of anaesthesia was monitored using a bispectral index (BIS) monitor. Electrocardiogram, heart rate, pulse oximetry, and non-invasive arterial blood pressure were monitored at 2-min intervals. Anaesthesia was induced with propofol 3.5 μg mL 1 and remifentanil 5 ng mL 1 at an effect site concentration using a target-controlled infusion (TCI) device. Anaesthesia was maintained with propofol and remifentanil continuous infusions. During surgery except the study period, propofol and remifentanil doses were adjusted to maintain BIS value of 40-60 and systolic blood pressure (SBP) within ±20% from baseline respectively.

Treatment:

Drug: Saline + Propofol