Second dose thiopentone attenuates the haemodynamic response to laryngoscopy and intubation.

The study was undertaken to evaluate the effectiveness of large (divided) thiopentone dosage on the peripheral haemodynamic response to laryngoscopy and intubation. Seventy-six (76) patient aged 18 to 67 years were sequentially assigned to either the second dose thiopentone group (n = 36) or the control group (n = 40). The first group had 4 mg.kg-1 thiopentone for induction of anaesthesia, then 1.5 mg.kg-1 suxamethonium chloride for muscle relaxation and a second dose of thiropentone (4 mg.kg-1) just before laryngoscopy and intubation. The control group had thiopentone 4 mg.kg-1 for induction of anaesthesia, suxamethonium 1.5 mg.kg-1 for muscle relaxation and then laryngoscopy and intubation. The heart rate (HR), systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), and rate pressure product (RPP) were measured before induction of anaesthesia and after laryngoscopy and intubation. The difference in the values represented the haemodynamic response to laryngoscopy and intubation. The second dose thiopentone technique compared with the control group, significantly attenuated the post-intubation rise in HR (19.7 vs. 30.9), SAP (18.0 vs. 37.5) and RPP (4795.4 vs. 8440.0). The post intubation rise in DAP (33.9 vs. 42.5) and MAP (31.9 vs. 42.0) didn't show significant difference between the two groups.