Amazing Supremacy of Thiopental Compared to Propofol in Rat Bronchi with Supramaximal Tonus

Introduction: Bronchospasm is an undesirable phenomenon in all phases of operation and anesthesia.Tracheal intubation after induction of anesthesia causes a measurable increase in the resistance of the respiratory system, which often results in bronchoconstriction.Propofol and thiopental have been used as an intravenous anesthetic agent in induction of anesthesia for many years.Barbiturates are recommended not be used in patients with risks due to bronchospasm-causing effects. Propofol is generally recommended for patients with asthma and bronchospasm due to bronchodilatation and muscle relaxant effects. In our study, we aimed to demonstrate this superiority of propofol to thiopental in rat bronchi with supramaximal tonus in a bronchospasm model.Materials and methods:A total of 30 adult male rats were divided into four groups. Double-blinded group T1 received 1x10-5 M thiopental at supramaximal contraction. In Group T2, 1x10-6M thiopental was applied at supramaximal contraction while in Group P1 1x10-1M propofol was applied at supramaximal contraction and in Group P2, 1x10-2M propofol was applied. Tissue voltages were measured with MAY GTA0303 GENIUS TRANSDUCER AMPLITUDE® and recorded in the Acknowledge MP100® program.Results:In Group T1, the reduction in tonus was statistically significant (estimated mean difference, -0.41; 95% confidence interval [CI], -0.36 to 1.18; p=0.000. In Group T2, the tonus difference was statistically significant (estimated mean difference, -0.20; 95% confidence interval [CI], -0.62 to 1.03; p=0.001).There was no statistically significance between tonus levels in neither group P1 nor group P2 before and after the implementationConclusion: In our study, relaxation effect in two different doses of thiopental was shown in rat bronchus tissue in in vitro bronchospasm model. Propofol did not show any relaxation or contraction responses in two separate doses. Surprisingly, Our results suggest that propofol has no direct bronchodilatation effect and thiopental provides bronchodilation. Consequently, we noticed that the effect of thiopental dose-dependent bronchodilatation is not well debate in the literature. For this reason, bronchodilatation doses of thiopental should be determined in further clinical and experimental studies.