The effects of neostigmine on pulmonary vascular tone

Abstract

The pulmonary vascular responses and changes in haemodynamics upon the administration of neostigmine were studied in patients undergoing elective abdominal tumour surgery. ,0.03 mg/kg neostigmine was given at the end of the surgical procedure when the patients started to breathe spontaneously. Haemodynamic parameters and pulmonary vascular responses were measured before and after neostigmine. The results of this study indicate that neostigmine lowers mean arterial blood pressure and prevents the increase of mean pulmonary arterial pressure and pulmonary vascular resistance. We suggest that neostigmine may exert its dilator effect in this pilot study directly or via a complex interaction with muscarinic receptors and/or increasing VİP secretion, or via enhancing NO production. However, the present data is inadequate to support one of the above hypotheses. Therefore, further clinical and experimental studies are required for exact mechanism.