In this prospective observational study we investigated the changes in cardiac index and mean arterial pressure in children when positioned prone for scoliosis correction surgery. Thirty children (ASA 1-2, aged 13-18 years) undergoing primary, idiopathic scoliosis repair were recruited. The cardiac index and mean arterial blood pressure (median (IQR [range])) were 2.7 (2.3-3.1 [1.4-3.7]) l.min(-1).m(-2) and 73 (66-80 [54-91]) mmHg, respectively, at baseline; 2.9 (2.5-3.2 [1.7-4.4]) l.min(-1).m(-2) and 73 (63-81 [51-96]) mmHg following a 5-ml.kg(-1) fluid bolus; and 2.5 (2.2-2.7 [1.4-4.8]) l.min(-1).m(-2) and 69 (62-73 [46-85]) mmHg immediately after turning prone. Turning prone resulted in a median reduction in cardiac index of 0.5 l.min(-1).m(-2) (95% CI 0.3-0.7 l.min(-1).m(-2), p=0.001), or 18.5%, with a large degree of inter-subject variability (+10.3% to -40.9%). The changes in mean arterial blood pressure were not significant. Strategies to predict, prevent and treat decreases in cardiac index need to be developed.
© 2013 The Association of Anaesthetists of Great Britain and Ireland.