Female patients with an American Society of Anesthesia (ASA) physical status I-II, scheduled for elective breast cancer surgery will be included in the study. Subjects will be randomly assigned to one of three groups: the placebo group, the low-dose S-ketamine group, and the high-dose S-ketamine group. The primary outcome is the consumption of sufentanil during the surgery.
All patients will be scheduled to a propofol-remifentanil general anesthesia and receive non-steroid anti-inflammatory drug before incision. Bolus sufentanil will be administered according to the blood pressure, heart rate and bispectral index perioperatively. Patients unable to understand the study procedure or unable to give informed consent, with concurrent analgesic or sedative medication, with history of chronic pain, psychiatric disorders, or alcohol or drug abuse, with an allergy to the study medication, who are pregnant or breast feeding, with a BMI \>30 and \<18 kg/m2, with severe cardiac, pulmonary, hepatic or renal dysfunction, with intracranial hypertension will be excluded. Subjects will be randomly assigned to one of three groups: the placebo group, the low-dose S-ketamine group, and the high-dose S-ketamine group. The study medication will be administered in a bolus injected over 30 s after induction, followed by continuous infusion, which started after the initial bolus. The placebo group will receive a bolus of 0.9% saline, followed by continuous infusion of 0.9% saline. The low-dose ketamine group will be administered a bolus of 0.5 mg/kg S-ketamine in saline, followed by 2μg/kg/min S-ketamine in saline, whereas the high-dose ketamine group will be administered a bolus of 0.5 mg/kg S-ketamine in saline, followed by continuous infusion of 4μg/kg/min S-ketamine in saline. The syringes and infusions will be identical for all of the groups and will run at the same rate in all subjects to enable blinding of the investigators. Study medication will be terminated 30 min prior to the end of the surgery. After surgery and in the postanesthesia care unit, patients will be asked about their pain level on a numeric rating scale (NRS), and about the presence of intraoperative awareness, nausea, vomiting, and hallucinations. Rescue analgesia of sufentanil will be provided when NRS ≥ 4 or patients require. Pain level will also be assessed at 0.5, 2, 4, 6, 12 and 24 hour postoperatively as well as 3 and 6 month after the surgery. Depression scale will be evaluated before the surgery and in the 7th postoperative day.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
345
Patients in the low-dose ketamine group will receive a bolus of 0.5 mg/kg S-ketamine in saline, followed by continuous infusion of 2 μg/kg/min S-ketamine in saline until 30 min prior to the end of the surgery.
Patients in the placebo group will receive a bolus of 0.9% saline, followed by continuous infusion of 0.9% saline until 30 min prior to the end of the surgery.
Patients in the high-dose ketamine group will receive a bolus of 0.5 mg/kg S-ketamine in saline, followed by continuous infusion of 4 μg/kg/min S-ketamine in saline until 30 min prior to the end of the surgery.
Second Affiliated Hospital of Anhui Medical University
Hefei, China
consumption of sufentanil
the consumption of sufentanil during the surgery.
Time frame: during the surgery
postoperative pain assessment
Patients will be asked about their pain level at rest and moving on a numeric rating scale evaluated on a 11-point (0 = no pain, 10 = worst pain imaginable).
Time frame: at 0.5, 2, 4, 6, 12 and 24 hours respectively after surgery; Month 3 and Month 6 after surgery
consumption of analgesics
cumulative analgesic consumption after surgery
Time frame: in the first 24 hour after surgery
Richmond Agitation-Sedation Scale (RASS)
Richmond Agitation-Sedation Scale is a 10-point scale. The values and definitions for each level of agitation and sedation are displayed as follows: +4, Combative, overtly combative or violent; immediate danger to staff; +3, Very agitation, pulls on or removes tube(s) or catheter(s) or has aggressive behavior toward staff; +2, Agitated, frequent nonpurposeful movement or patient-ventilator dyssynchrony; +1, Restless, anxious or apprehensive but movements not aggressive or vigorous; 0, Alert and calm; -1, Drowsy, not fully alert, but has sustained (more than 10 seconds) awakening, with eye contact, to voice; -2, Light sedation, briefly (less than 10 seconds) awakens with eye contact to voice; -3, Moderate sedation, any movement (but no eye contact) to voice; -4, Deep sedation, no response to voice, but any movement to physical stimulation; -5, Unarousable, no response to voice or physical stimulation
Time frame: 30 minutes after surgery
sleep quality scale
Quality of sleep in the night of surgery day using a 4-point scale (1 = "slept well," 2 = "disturbed sleep," 3 = "nightmares," and 4 = "sleepless") will be recorded.
Time frame: sleep quality scale will be assessed in the morning (8:00 am）of first postoperative day
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consumption of propofol
the consumption of propofol during the surgery.
Time frame: during the surgery
consumption of remifentanil
the consumption of remifentanil during the surgery.
Time frame: during the surgery
length of anesthesia
from beginning to the end of anesthesia
Time frame: at the end of anesthesia
length of surgery
from beginning to the end of surgery
Time frame: at the end of surgery
recovery time
awakening time from surgery
Time frame: at the time when patients waking up
consumption of vasoactive agents
the consumption of any vasoactive agent (such as phenylephrine, urapidil, ephedrine)
Time frame: during the surgery
blood pressure
noninvasive blood pressure
Time frame: before anesthesia, prior to incision, 5, 10, 30, 60 and 120 minutes after incision, at the end of surgery and 30 minutes after surgery
heart rate
Heart rate of the patients
Time frame: before anesthesia, prior to incision, 5, 10, 30, 60 and 120 minutes after incision, at the end of surgery and 30 minutes after surgery
bispectral index
Bispectral index during the surgery
Time frame: before anesthesia, prior to incision, 5, 10, 30, 60 and 120 minutes after incision, at the end of surgery and 30 minutes after surgery
adverse effects
The presence of intraoperative awareness, nausea, vomiting, and hallucinations after surgery
Time frame: through 24 hours after the surgery
Edinburgh postnatal depression scale
Depression scale generated from Edinburgh postnatal depression scale will be assessed. The minimum value is 0, and the maximum value is 30. The higher score means the higher possibility of depression.
Time frame: before surgery, at the 7th day and 3 months after surgery
ambulation time
interval time of patients' transit from bed rest to ambulation after surgery
Time frame: 7 days after surgery
hospitalization postoperatively
days of hospital staying after surgery
Time frame: two weeks after surgery