Effects Of Mechanical Ventilation On The Serum PAI-1 Expression In Patients During Neurosurgery Operation

Objective:To investigate the effects of mechanical ventilation on serum PAI-1 expression and pulmonary function in patients during neurosurgery operation.Methods:To select 60 patients undergoing general anesthesia in neurosurgery operation,no lung disease, no fever, no smoking history, with supine position in the operation. All the patients preoperative chest radiography examinations were normal, vital signs were stable, with no anemia or hypoproteinemia. The patients were randomly divided into three groups: group A(tidal volume, 6ml/kg, n=20), group B(tidal volume, 8mg/kg, n=20), group C(tidal volume, 12ml/kg, n=20). To adjust the breath frequency during operation in order to maintain end-tidal carbon dioxide tension(PETCO2) at 35±5mm Hg with flow 2L/min, I:E ratio 1:2, inspired oxygen concentration100%. The vital signs were recorded and the extract radial venous blood were collected at different time points: before anesthesia induction(T0), mechanical ventilation for 1hour(T1), mechanical ventilation for 3 hours(T2), mechanical ventilation for 5 hours(T3). To observe the mean arterial pressure(MAP), heart rate(HR), the expression change of PAI-1 in the serum. Recorded respiratory mechanical parameters parallel blood-gas analysis at T0, T1, T2,T3, and observed the changes of peak inflation pressure(Ppeak), platform airway pressure(Pplat), the partial pressure of arterial carbon dioxide(Pa CO2), the partial pressure of arterial oxygen(Pa O2). Calculated the partial oxygen pressure of alveolar-arterial(P(A-a)O2) and oxygenation index(Pa O2/Fi O2).Results:The mean arterial pressure and the heart rate in each group at different time points had no statistically difference(P>0.05). Comparison among three groups: the serum PAI-1 expression of group C was up-regulated than group A at T3, and the difference is statistically significant(P<0.05). Comparisons in each Group: With the ventilation time prolonged, the expression of serum PAI-1 were increased in each three group, but there was no statistically significant difference between group A and group B at each time point. The serum PAI-1 expression of group C at T3 is up-regulated than T0, and the difference is statistically significant(P<0.05). The peak airway pressure and plateau airway pressure of group C is higher than group A and group B at T1, T2, T3, and the difference is statistically significant(P<0.05). The arterial oxygen partial pressure(Pa O2)and alveolar-arterial partial oxygen pressure(P(A-a)O2) of three group at T1, T2, T3 are up-regulated than T0, and the difference is statistically significant(P<0.05). The arterial carbon dioxide partial pressure(Pa CO2) and oxygenation index(Pa O2/Fi O2) had no statistically significant difference in each group at different time points(P>0.05).Conclusion:Mechanical ventilation can up-regulate the expression of patients serum PAI-1during neurosurgery operation.The PAI-1 expression is changed after mechanical ventilation for 1 hour; The expression of patients serum PAI-1 during neurosurgery operation is related with tidal volume and ventilation time, 12ml/kg and ventilation 5hours later, the serum PAI-1 expression is up-regulated significantly; The patients’ pulmonary function don’t change with the increase of serum PAI-1.