The effect of low versus high tidal volume ventilation on inflammatory markers in healthy individuals undergoing posterior spine fusion in the prone position: A randomized controlled trial

Study Objective: To evaluate the effect of ventilation strategy on markers of inflammation in patients undergoing spine surgery in the prone position. Design: Randomized controlled trial. Setting: University-affiliated teaching hospital. Patients: 26 ASA physical status 1 and 2 patients scheduled for elective primary lumbar decompression and fusion in the prone position. Interventions: Patients were randomized to receive mechanical ventilation with either a tidal volume (V_T) of 12 mL/kg ideal body weight with zero positive end-expiratory pressure (PEEP) or V_T of 6 mL/kg ideal body weight with PEEP of 8 cm H₂O. Measurements: Plasma levels of interleukin (IL)-6 and IL-8 were determined at the beginning of ventilation and at 6 and 12 hours later. Urinary levels of desmosine were determined at the beginning of ventilation and on postoperative days 1 and 3. Main Results: A significant increase in IL-6, IL-8, and urine desmosine levels was noted over time compared with baseline (P < 0.01). However, no significant difference in the levels of markers was seen between the groups at any time point when controlling for demographics, ASA physical status, body mass index, duration of ventilation, or estimated blood loss. Conclusions: Although markers of inflammation are increased after posterior spine fusion surgery, ventilation strategy has minimal impact on markers of systemic inflammation.