Influence of remifentanil combined with propofol for controlled hypotension on gastric intramucosal pH

Objective: To discuss the influence of remifentanil combined with propofol for controlling hypotension on gastric intramucosal pH(pHi).Methods: Twenty patients undergoing elective vertebral fracture internal fixation,femoral shaft fracture internal fixation or hip replacement patients were randomly divided into two groups.The test group(n=10) received remifentanil and propofol for anesthesia and lowering blood pressure,and control group(n=10) received fentanyl and propofol for anesthesia and sodium nitroprusside(SNP) for lowering blood pressure.The MAP,SBP,DBP,HR,CVP,PgCO₂,arterial blood gas and pHi at the time point T₀(before the blood pressure lowering),T₁(immediate relief and stability),T₂(blood pressure dropping 10 min),T₃(blood pressure dropping 30 min),T₄(hypotension 1 h),T₅(stopping blood pressure dropping 10 min) and T₆(stopping blood pressure dropping 30 min) were determined and compared between the both groups.Results: In the test group,the value of PgCO₂ at the time point T₂,T₃,T₄ were obviously higher than that at T₀ and T₁(P<0.05);pHi at T₃ and T₄ were lower than that at T₀ and T₁(P<0.05).The value of PgCO₂ increased from 46.5 mmHg(T₀) to 70.8 mmHg(T₄),and recovered at T₆.In control group,the value of PgCO₂ at T₂,T₃,T₄ and T₅ were higher than that at T₀ and T₁(P<0.05);the value of pHi at T₂,T₃,T₄ and T₅ were obviously lower than that at T₀(P<0.01).The value of PgCO₂ increased from 47 mmHg(T₀) to 79 mmHg(T₄),and recovered at T₆.The value of PgCO₂ at T₂,T₃ and T₄ in the test group were obviously lower than that in control group(P<0.01),whereas the pHi at T₃ and T₅ were higher than that in control group(P<0.01).Conclusions: The transient gastrointestinal microcirculation disturbance can be found in controlling hypotension by remifentanil and propofol,but it is obvious smaller than by the traditional medicine SNP,and can be recovered in 10 min after stopping the medicine.