Study on blood gas analysis in directing controlled respiration under general anesthesia

Objective To evaluate the clinical significance of arterial blood gas analysis in directing controlled mechanical ventilation under general anesthesia.Methods 197 adult patients who received operation under general anesthesia were administered controlled mechanical ventilation.These patients would be set ventilation parameters as follows:VT:8.77±1.21 ml/kg,f:12 bpm,I ∶ E:1 ∶ 2,and fresh gas of purified oxygen:2 L/min.Arterial blood gas analysis was made 20 min after anesthesia and per hour thereafter.The patients whose first arterial blood gas analysis values were abnormal were made another blood gas analysis 20 min after adjusting their raspixatory parameters.Results The first blood gas analysis values of the patients showed that the average PaCO2 value was 33.45±12.76 mmhg,only 44.7% were normal.The average PH value was 7.406±0.0544(65.99% were normal).109 cases of first PaCO2 were abnormal which ventilation parameters were adjusted according to their first PaCO2.The second blood gas analysis values of the patients showed that the average PaCO2 value was 37.11±4.64 mmhg,89.3% were normal and higher than the first(P0.05).The average PH value was 7.384±0.0211,92.89% were normal and it was higher than the first(P0.05).Conclusions It has important clinical significance significant for arterial blood gas analysis to direct controlled respiration under general anesthesia.