Orthostatic haemodynamic responses in acute stroke

Little is known about orthostatic blood pressure regulation in acute stroke . We determined postural haemodynamic responses in 40 patients with acute s troke (mild or moderate severity) and 40 nonstroke control in-patients, at two days ('Day 1') and one week ('Week 1') postadmission. Following a 10-mi nute supine rest and baseline readings, subjects sat up and blood pressure and heart rate were taken for 5 minutes. The procedure was repeated with su bjects moving from supine to the standing posture. Haemodynamic changes fro m supine data were analysed. On standing up, the control group had a transi ent significant fall in mean arterial blood pressure on Day 1 but not Week 1. No significant changes were seen on either day when sitting up. In contr ast to controls, the stroke group showed increases in mean arterial blood p ressure on moving from supine to the sitting and standing positions on both days. Persistent postural hypotension defined as greater than or equal to 20 mmHg systolic fall occurred in <10% of either of the study groups on bot h days. Sitting and standing heart rates in both groups were significantly faster than supine heart rate on both days. The orthostatic blood pressure elevation is consistent with sympathetic nervous system overactivity which has been reported in acute stroke. Upright positioning as part of early reh abilitation and mobilisation following mild-to-moderate stroke would, there fore, not predispose to detrimental postural reductions in blood pressure.