[Ketamine inhalation before one-lung ventilation for perioperative lung protection in thoracic surgery patients]

To explore the effects of ketamine inhalation before one-lung ventilation (OLV) in patients undergoing transthoracic esophagectomy for esophageal cancer.

Upon the approval of hospital ethic committee, 90 American Society of Anesthesiologists grade I-II patients scheduled for elective trans-left-thoracic esophagectomy for esophageal cancer were randomly and single-blindly divided into 3 groups. After intravenous anesthesia with double-lumen endobronchial intubation, the patients in each group received different therapies before OLV, i.e. inhaling ketamine 1 mg/kg in Group Ki, intravenous infusion of ketamine 1 mg/kg in Group Kv and inhaling normal saline 10 ml in Group C. Arterial blood gas analysis was performed. And (oxygen saturation) SpO2, (partial pressure of end-tidal carbon dioxide) PETCO2, (airway pressure) Paw and hemodynamic indicators were recorded at these points:before OLV (T1), OLV for 30 min (T2), OLV for 1 h (T3), OLV for 2 h (T4), OLV ended 5 min (T5) and end of surgery (T6). Central venous blood was sampled at T1, T2 and 2 h after surgery (T7) for the determination of interleukin-6 (IL-6), interleukin-8 (IL-8) and soluble intercellular adhesion molecule-1 (sICAM-1) concentrations by enzyme-linked immunosorbent assay (ELISA).

Serum levels of IL-6, IL-8 and sICAM-1 in all groups increased significantly than those at previous timepoints. Serum levels of IL-6, IL-8 and sICAM-1 in Groups Ki and Kv were significantly lower than those in Group C at T7. PaO2 in Groups Ki and Kv was significantly higher than that in Group C at T4. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) in Group Kv were significantly higher than that in Groups Ki and C at T2-T4; HR in Group Kv was significantly higher than that in Group C at T2-T3. Paw in Group Kv was significantly higher than that in Group C at T2-T6.

Inhalation and intravenous infusion of ketamine before OLV are equally effective in lowering the serum levels of IL-6, IL-8 and sICAM-1. And ultrasonic atomizing inhalation of ketamine can avoid adverse effects on airway pressure and circulatory system caused by an intravenous infusion of ketamine.