Effect of Heated Breathing Circuit on Intraoperative Core Temperature and Systemic Inflammation After Brain Surgery: a Prospective Randomized Study

Effect of Heated Breathing Circuit on Intraoperative Core Temperature and Systemic Inflammation After Brain Surgery: a Prospective Randomized Study

Effect of Heated Breathing Circuit on Intraoperative Core Temperature and Systemic Inflammation After Brain Surgery: a Prospective Randomized Study

Mechanical respiration during general anesthesia causes cold and dry gases to reach the lower airway, reduce the function of the airway mucosa, and cause accumulation of secretions. Inhaled dry gas is one of the causes of hypothermia during general anesthesia. To overcome this, the warm-humidifying breathing circuit uses warm, moisture-preserving gas to promote mucus mobility of the airway mucosal ciliate cells and prevents cold gases from evaporating from the mucosal surfaces which results lowering body temperature. We aimed to investigate the effect of newly developed Sohum warm humidifying respiration circuit (SH501) on the prevention of core body temperature reduction during surgery and systemic inflammation reaction.

The patient enters the operating room without any pretreatment and attaches a standard patient monitoring device. Anesthesia was performed by intravenous anesthesia. After induction of anesthesia, alveolar recruitment is performed in supine position in all groups with 30 cmH2O for 5 seconds. Mechanical ventilator was set with tidal volume of 8 ml / kg, the inspiratory/ expiratory ratio of 1: 2 and respiratory rate was adjusted for targeting EtCO2 around 35mmHg. Keep the fresh air flow of the ventilator at 3 L / min and set the temperature to 37 ° C for the heating circuits of group H and group SH. An arterial cannulation and subclavian jugular vein catheter is inserted. The circuits were applied to each group as follows; conventional circuit or group C, conventional humidification circuit for group H and new humidification heat circuit for group SH, respectively. All other conditions were same among three groups.

The patient enters the operating room without any pretreatment and attaches a standard patient monitoring device. Anesthesia was performed by intravenous anesthesia. After induction of anesthesia, alveolar recruitment is performed in supine position in all groups with 30 cmH2O for 5 seconds. Mechanical ventilator was set with tidal volume of 8 ml / kg, the inspiratory/ expiratory ratio of 1: 2 and respiratory rate was adjusted for targeting EtCO2 around 35mmHg. Keep the fresh air flow of the ventilator at 3 L / min and set the temperature to 37 ° C for the heating circuits of group H and group SH. An arterial cannulation and subclavian jugular vein catheter is inserted. The circuits were applied to each group as follows; conventional circuit or group C, conventional humidification circuit for group H and new humidification heat circuit for group SH, respectively. All other conditions were same among three groups.

The patient enters the operating room without any pretreatment and attaches a standard patient monitoring device. Anesthesia was performed by intravenous anesthesia. After induction of anesthesia, alveolar recruitment is performed in supine position in all groups with 30 cmH2O for 5 seconds. Mechanical ventilator was set with tidal volume of 8 ml / kg, the inspiratory/ expiratory ratio of 1: 2 and respiratory rate was adjusted for targeting EtCO2 around 35mmHg. Keep the fresh air flow of the ventilator at 3 L / min and set the temperature to 37 ° C for the heating circuits of group H and group SH. An arterial cannulation and subclavian jugular vein catheter is inserted. The circuits were applied to each group as follows; conventional circuit or group C, conventional humidification circuit for group H and new humidification heat circuit for group SH, respectively. All other conditions were same among three groups.

Inclusion Criteria: age ≥ 19 scheduled for brain surgery Exclusion Criteria: age < 19 patients with severe obstructive lung disease and/or restrictive lung disease patients patients with infectious disease surgery with prone position or lateral position arrhythmia

Department of Anesthesiology and Pain Medicine, Anesthesia and Pain Research Institue, Yonsei Universiy College of Medicine