Objective  To observe effect of two-pipe heating CO₂ moister blower in improving intraoperative hypothermia in patients undergoing off-pump coronary artery bypasses grafting (OPCAB).

  Methods  Thirty OPCAB patients were selected as research objects and divided into control group and observation group by random number table method, with 15 cases in each group. In the control group, CO₂ moister unheated blower with a liquid pipe of 37℃ normal saline was used to expel blood, while the observation group was used the two-pipe heating CO₂ mister blower to expel blood. A comparative analysis was made over the aerosol temperature, heart rate variability, and core temperature of the two groups.

  Results  The aerosol temperature of the observation group was higher than that of the control group at 2.5 min after takeover and 30.0 min after moist blowing (P < 0.05). Compared with 2.5 min after takeover, the aerosol temperature in the control group decreased significantly when blowing fog for 30.0 min(P < 0.05). There was no significant difference in the aerosol temperature of the observation group at 2.5 min after takeover and 30.0 min after blowing fog (P>0.05). The qualified rates of core body temperature in the observation group were higher than that in the control group at the time points of opening pericardium, blowing fog for 3.0 min, closing pericardium and before leaving the room (P < 0.05). The heart rate variabilities of the observation group were lower in the observation group than those of the control group at 3 minutes, 10 minutes, 20 minutes and 30 minutes after moist blowing (P < 0.05).

  Conclusion  Aerial fog is warm and constant after application of two-pipe heating CO₂ moister blower in OPCAB patients during surgery, and hypothermia of patients is improved and the heart rate variability is relatively low, which can effectively prevent the hypothermia caused by OPCAB surgery.