Emergence agitation in adults: risk factors in 2,000 patients

The study was designed to determine the incidence of postoperative agitation following general anesthesia in 2,000 adult patients and to examine the associated risk factors.

The study enrolled 2,000 adults who were scheduled for surgery under general anesthesia in a single institution during December 2007 to December 2008. The following risk factors were examined: age, gender, ASA physical status, type of surgery, anesthesia technique (inhalational or intravenous), administration of neostigmine or doxapram, adequate postoperative analgesia, pain, presence of a tracheal tube, and presence of a urinary catheter.

Agitation occurred in 426 patients (21.3%). It was more common in males (28.1%) than in females (16.1%) (P = 0.017) and more prevalent after inhalational (27.8%) than total intravenous (7.5%) anesthesia (P = 0.001). Agitation was more common after oral cavity and otolaryngological surgery than after other types of surgery. Multivariate analysis showed that use of doxapram (odds ratio [OR] = 9.2; 95% confidence interval [CI] = 6.2 - 15.4; P = 0.002) and pain (OR = 8.2; 95% CI = 4.5 - 16.9; P < 0.001) were the most important risk factors associated with emergence agitation. Other causes were the presence of a tracheal tube and/or a urinary catheter. Adequate postoperative analgesia was associated with less agitation (OR = 0.4; 95% CI = 0.1 - 0.4; P = 0.006).

Doxapram administration, pain, and presence of a tracheal tube and/or a urinary catheter appear to be the most important causes of postoperative agitation. To avoid this complication, it is suggested, whenever possible, to use intravenous anesthesia, to remove endotracheal tubes and urinary catheters as early as possible, and to provide adequate postoperative analgesia.