Effect Of Small Tidal Volume Combined With Low Level PEEP On Intraocular Pressure In Patients Undergoing Laparoscopic Rectal Cancer Surgery

Objective To observe the effect of small tidal volume combined with low-level PEEP（positive end-expiratory pressure）ventilation mode on intraocular pressure（IOP）of patients undergoing laparoscopic rectal cancer surgery,and provide a reference for clinical.Methods Forty patients with selective laparoscopic radical rectal cancer surgery in the General Hospital of Ningxia Medical University were selected（all the same group of surgeons）.They were ASA II^III,aged 18⁶5 years old,body mass index is 18²5kg?m^-1.The random number table method randomly divided patients into two groups:Conventional tidal volume ventilation mode（group V,n=20）and small tidal volume combined with low-level PEEP ventilation group（group P,n=20）.Adjust the tidal volume（VT）to 10ml?kg^-11 in group V,adjust the tidal volume to 6 ml?kg^-1in group P,and add PEEP of5cmH₂O.Record and compare the general conditions of the two groups of patients and systolic pressure（SBP）,diastolic pressure（DBP）,heart rate（HR）,central venous pressure（CVP）,airway plateau pressure（PLAT）,peak airway pressure（PEAK）,and end-expiration CO₂ partial pressure(P_ETCO₂),left eye IOP（LIOP）,right eye IOP（RIOP）.Time points include:resting in the supine position for 10 minutes（T₁）,immediately after anesthesia-induced tracheal intubation（T₂）,5 minutes after the establishment of the pneumoperitoneum（T₃）,60min after the pneumoperitoneum+30°head down position（T₄）,90minutes after pneumoperitoneum+30°head down position（T₅）,20 minutes after pneumoperitoneum release to supine position（T₆）.Results 1.Comparison between groups:There was no significant difference in SBP,DBP,HR,CVP,PEAK,PLAT,P_ETCO₂,LIOP,and RIOP in T₁-T₆ between the two groups （P>0.05）.2.Comparison at different time points:Compared with time T₁,the SBP,DBP and HR decreased significantly in the patients of the two groups（V and P）at T₂,T₄,T₅,and T₆,and all（P<0.05）the difference was statistically significant.Compared with time T₁,the CVP increased significantly in the patients of the two groups（V and P）at T₃,T₄,T₅ and all（P <0.05）the difference was statistically significant.Compared with time T₂,the PEAK,PLAT and P_ETCO₂ increased significantly in the patients of the two groups（Vand P）at T₃,T₄,T₅ and all（P<0.05）had significant statistical difference.Compared with time T₁,the LIOP and RIOP decreased significantly in the patients of the two groups（V and P）at T₂,the LIOP and RIOP increased significantly in the patients of the two groups（V and P）at T₃,T₄,T₅,and all（P<0.05）had significant statistical difference.Compared with time T₃,the LIOP and RIOP increased significantly in the patients of the two groups（V and P）at T₅,and（P<0.05）had significant statistical difference.Compared with time T₄,the LIOP and RIOP increased significantly in the patients of the two groups（Vand P）at T₅,and（P<0.05）had significant statistical difference.Conclusion During laparoscopic radical rectal cancer surgery,pneumoperitoneum and low head position can increase patients IOP,and small tidal volume combined with low-level PEEP or conventional volume ventilation mode can also increase patients’IOP,but remain within the normal range.Safe to use in such patients.