Effect of Esketamine on Depressive Symptoms of Obese Patients Undergoing Laparoscopic Sleeve Gastrectomy

Esketamine, as a powerful analgesic intravenous anesthetic, has a rapid onset and elimination effect, does not inhibit spontaneous respiration, and can slightly stimulate the circulatory system. It has been confirmed that esketamine can effectively combat opioid related complications, especially life-threatening respiratory suppression. Thus becoming a new powerful perioperative analgesic drug. At the same time, esketamine has been licensed for the treatment of "resistant depression" and emergency treatment for patients in crisis states of depression. But the evidence for its safety and effectiveness is insufficient. We have designed a randomized controlled clinical trial to investigate the effect of an established general anesthesia strategy without opioids by using esketamine on postoperative depressive in obese patients undergoing laparoscopic sleeve gastrectomy.

The bidirectional relationship between obesity and mood disorders is suggested supported by empirical evidence. Obesity increases the risk of depression, and depression predicts the developing of obesity. The associations between atypical depressive symptoms and obesity-related characteristics may consequent to sharing pathophysiologic characteristics in patients with major depressive disorders, such as genetics, and brain circuitries integrating homeostatic and mood regulatory responses.

Bariatric surgery is a remarkably effective and durable treatment for obesity, resulting in considerable weight loss, and reductions in the prevalence of type 2 diabetes mellitus, hypertension, dyslipidemia and sleep apnea at 5 years. Nearly 23-33% of patients undergoing bariatric surgery report a preoperative depression. Meanwhile, bariatric surgery is consistently associated with postoperative decreases in the prevalence of depression (8%-74% decrease) and the severity of depressive symptoms (40%-70% decrease) at 6-month, 12-month, 24-month. In 357 extremely obese patients with a mean BMI of 51.2 kg/m2, 45% of patients are identified as depression before gastric bypass surgery. And by 6-, 12-, 24-month follow-up, by using Beck Depression Inventory, clinically significant depressive symptoms are characterized to 12%, 13% and 18%, respectively. Compared with status prior to surgery, the prevalence of any Axis I psychiatric disorder for DSM-IV at 2 and 3 years after Roux-en-Y gastric bypass or laparoscopic adjustable gastric band surgery is significantly reduced from 30.2% to 16.8% and 18.4%.

Based on the HAMD assessments, we found that the incidence of depressive symptoms was 71.1% in 225 young obese patients (31.0 years-old) before laparoscopic sleeve gastrectomy. The depressive symptoms and severity were improved over time, particular in postoperative 3 months. However, depressive symptoms were still sustained in a proportion of obese patients.

Eligibility Criteria:
Inclusion Criteria:

* BMI≥40kg/m2 or BMI\>35 kg/m2 with an existing comorbidity
* scheduled for selective LSG
* American Society of Anesthesiologists physical status I-III
* HAMD\>7
* with informed consent

Exclusion Criteria:

* Patients diagnosed with significant comorbidities, such as cardiopathy, chronic respiratory conditions, abnormal hepatic and/or renal function, coagulation dysfunction, major psychiatric or neurological disorders
* Patients allergy to esketamine or other drugs used in the study
* Patients are scheduled for/plan to have an additional surgery during the 3-month follow-up period
* Patients suffer from acute or chronic pain with analgesics, or take anticathartic, glucocorticoid medications
* Patients involved in another research study
* Patients will likely have problems, in the judgement of the investigator, with maintaining follow-up
* Any other reasons the investigator feels is relevant for excluding the patient
* lack of patient consent