Effect of propofol and thiopentone on intracranial pressure and cerebral perfusion pressure in patients undergoing elective craniotomy - a comparative study

Advantages and disadvantages of newer agent like propofol need to be evaluated with time tested inducing drug - thiopentone in neuroanaesthesia. The aim of the study was to compare effects of propofol with thiopentone on intracranial pressure, cerebral perfusion pressure and haemodynamics during induction in neurosurgical pa­tients. Fifty adult patients of ASA grade I& II scheduled for elective craniotomy were randomly assigned to receive induction of anaesthesia with either propofol 1.5-2.5 mg.kg -1 i.v. (Group A, n=25) or thiopentone 4-5 mg.kg -1 , i.v. (Group B, n=25). Vecuronium bromide 0.1 mg.kg -1 i.v. was used as intubating muscle relaxant. Both groups received fentanyl 2 pg.kg -1 i.v., lidocaine(preservative free) 1.5 mg.kg -1 i.v. and supplementary dose of same inducing agent before intubation. Changes in mean arterial pressure (MAP), cerebrospinal fluid pressure (CSFP), cerebral perfusion pressure (CPP) and heart rate (HR) were noted during induction and endotracheal intubation. On statistical analysis it was found that CSFP decreased significantly (P<0.001) in both groups after induction but endotracheal intubation did not provoke any significant rise in CSFP. Maximum decrease of CSFP was 35.26% in Group A and 35.20% in Group B. Fall in MAP was more significant in Group A (P<0.001), as a result CPP was significantly less in Group A than in Group B. The lowest mean CPP (71.12±5.86 mm Hg) was observed 2 minutes after induction dose in Group A when maximum drop in MAP occurred. Heart rate did not change significantly in Group A but in Group B fluctuation of heart rate was more.