| Objective To investigate the effects of airway humidification by an oxygen driven jet type nebulizer applied to mechanically ventilated patients under general anesthesia and the effects of airway humidification on postoperative pulmonary complications.Methods A total of 78 patients,aged over 18 years,with BMI:18.5-29.9kg/m2,ASA grade II-III,who scheduled for gastrointestinal cancer surgery in our hospital were selected.According to the random number table,78 patients divided into drug nebulized and humidified（H1 group,n=26 patients）,non drug nebulized and humidified（H2 group,n=26patients）,and control group（C group,n=26 patients）.All the three groups were given intravenous anesthesia.After anesthesia induction,volume-controlled ventilation was adopted.Patients in groups H1 and H2 were connected with a jet nebulizer between the inspiratory branch and the Y-shaped part,driven by a compressed oxygen source,with oxygen flow rate adjusted to 5L/min and fresh gas flow rate set to 1L/min from anesthesia machine.The atomization was started from the beginning of endotracheal intubation,and the atomization was terminated 20minutes later in the humidification group and the atomizer was removed.Group H1 was atomized with inhaled acetyl cysteine solution,and group H2 was atomized with 0.45%saline solution.In the first 20 minutes of the control group,the anesthetic machine provided the same flow rate and ratio of fresh gas as the humidification group,without other intervention measures.The airway temperature and humidity measurements were performed and recorded using the MIAOXIN（TH10R-EX）temperature and humidity recorder immediately after intubation（T0）,20 min of mechanical ventilation（T1）,60 min of mechanical ventilation（T2）,and half an hour before the end of surgery（T3）;Heart rate（HR）,mean arterial pressure（MAP）,expiratory tidal volume（Ve）and airway peak pressure（Ppeak）were observed and recorded at all times.Preoperative(Tpre),T1,T2 and T3 arterial blood gas fractions were recorded,including PH value,oxygen partial pressure（PO2）and carbon dioxide partial pressure（PCO2）.Fiberoptic bronchoscopic airway examination was performed at T3 to observe sputum formation;Sputum volume and sputum viscosity were followed up and recorded half an hour after surgery(T4),the first day after surgery（T5）and the third day after surgery（T6）.Hospitalization records were consulted and the incidence of postoperative pulmonary complications（PPCs）（%）and postoperative length of stay（d）were recorded.Results A total of 78 patients were included in the final analysis.There were no significant differences in preoperative general situation,lung function,intraoperative body temperature,mean arterial pressure and heart rate among the three groups（P>0.05）.Compared with group C,airway RH and AH in group H1 at T1,T2 and T3 were significantly higher than those in control group（RH:100.00±0%vs 61.36±2.05%,94.94±1.50%vs 74.9±2.38%,91.97±1.86%vs 88.64±2.64%AH:19.55±0.76mg H2O/L vs 12.42±0.59mg H2O/L,20.14±0.69mg H2O/L vs 15.45±0.65mg H2O/L,20.23±0.84mg H2O/L vs 19.28±0.77mg H2O/L）,Similar conclusions were obtained in H2 group（RH:100.00±0%vs 61.36±2.05%,95.26±2.31%vs 74.9±2.38%,92.25±3.50%vs 88.64±2.64%AH:19.03±0.95mg H2O/L vs 12.42±0.59mg H2O/L,20.33±1.10mg H2O/L vs 15.45±0.65 mg H2O/L,20.52±1.30 mg H2O/L vs 19.28±0.77 mg H2O/L）,There was no significant difference in RH and AH between H1 and H2groups at different time.The sputum viscosity satisfaction rate of H1,H2 and C groups decreased successively at T3 moment and T5 time,the difference was statistically significant（T3:X2=11.55,P=0.003,T5:X2=6.323,P=0.042）.There was no significant difference in the incidence of PPCs among the three groups during hospitalization（P=0.458）.There was no significant difference in the number of days of postoperative hospitalization among the three groups（P=0.512）.Conclusion 1.For patients undergoing gastric tumor surgery under general anesthesia and mechanical ventilation,short-term atomizing humidification after the establishment of artificial airway can increase airway humidity and improve the satisfaction rate of phlegm viscosity during the operation and on the first day after surgery.2.Short-term intraoperative atomizing humidification could not reduce the incidence of postoperative pulmonary complications. |
