Figure 71-12 Time of onset of hypertension in 60 patients in whom hypertension developed after surgery. More than half had a history of hypertension. Pain, emergence excitement, hypercapnia, hypoxemia, and volume overload were common etiologies. (From Gal TJ, Cooperman LH: Hypertension in the immediate postoperative period. Br J Anaesth 47:70, 1975.)