Figure 2From: Effects of body position on the ventilatory response to hypercapnia Slope of the ventilatory (A) and esophageal pressure (B) responses to hypercapnia at P ET CO 2 of 65 mmHg in both supine and head-down tilt positions. (*) Significant difference between the slopes in supine and head down-tilt (HDT) positions (P < 0.05).Back to article page