Haemodynamic Changes at Induction during Laryngeal Mask Airway Insertion: Comparison of Propofol Versus Lignocaine-Thiopentone Admixture

Propofol is considered the standard induction agent for laryngeal mask airway (LMA) insertion but the search for other cost-effective methods with haemodynamic advantages continue. The objective of this study was to determine the haemodynamic changes at induction and during LMA insertion comparing propofol alone versus lignocaineThiopentone admixture. In this comparative randomized study, patients of American Society of Anesthesiologists' (ASA)class I and II age between 18-60 years scheduled for short elective surgeries were assigned into two equal groups. Patients were premedicated with fentanyl 1ug.kg-1. Anaesthesia was induced with either 2.5mg.kg-1 propofol (group A) or a sequence of 2mg.kg-1 lignocaine and 5mg.kg-1 thiopentone (group B). Anaesthesia was maintained with 2% isoflurane and 100% oxygen. Haemodynamic variables [Heart Rate(HR), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP) and Mean Arterial Pressure (MAP)] were measured non-invasively during three periods; before induction, immediately after induction, prior to insertion of LMA and after LMA insertion. Data was analysed using SPSS with p˂0.05considered significant. We concluded that propofol and lignocaine-thiopentone admixture exhibited similar haemodynamic profile and therefore recommended that both drugs could be used for patients during induction of anaesthesia and LMA insertion.