RESUMO
BACKGROUND: Alpha-2 adrenergic agonists produce safe and effective analgesia, but most investigations studying the analgesic effect of alpha-2 adrenoceptor agonists postoperatively included previous or concomitant administration of other analgesics. Because clonidine potentiates the effect of these drugs, its own intrinsic analgesic effect has been difficult to establish. This study was designed to compare the intraoperative and postoperative effects of epidural clonidine vs bupivacaine for patients undergoing lower abdominal surgery. METHODS: This randomized controlled trial included 40 patients aged 18-50 who were scheduled for elective lower abdominal surgery. Patients were randomly divided into 2 groups. Group I (n=20) received epidural clonidine; Group II (n=20) received epidural bupivacaine. Intraoperative and postoperative hemodynamics, pain scores, and complications were monitored. RESULTS: Mean pain scores were significantly lower in Group I compared to Group II (1.5 ± 0.5 compared to 3.4 ± 1.0, respectively) in the first 12 hours after surgery. Sedation was more prominent in Group I until 9 hours after surgery. Opioid requirements were significantly lower in Group I. Respiratory rate was similar in the 2 groups. Group I had larger decreases from baseline in systolic blood pressure and diastolic blood pressure than Group II. Heart rate in Group I was reduced from baseline, while it was increased in Group II. Less postoperative nausea and vomiting, urinary retention, pruritus, and shivering were observed in Group I. CONCLUSION: Compared to bupivacaine, epidural clonidine provided effective intraoperative and postoperative analgesia in selected patients, resulting in a decreased intravenous pain medication requirement and prolonged duration of analgesia after epidural infusion was discontinued.
RESUMO
BACKGROUND: When temporary arterial occlusion of the parent artery is difficult for anatomical reasons, or when inadvertent aneurysmal rupture occurs during surgical dissection, adenosine administration can be used to produce flow arrest and brief, profound systemic hypotension that can facilitate intracranial aneurysm clip ligation. There is a concern, however, that the flow arrest and profound hypotension produced by adenosine, although brief, may cause cerebral ischemia and therefore worsen neurologic outcome compared with other techniques to facilitate aneurysm clip ligation. Therefore, we performed a retrospective, case-control study to determine whether adenosine-induced flow arrest had negative effects on the neurologic outcome of our patients. METHODS: We reviewed the perioperative records of all patients in our intracranial aneurysm surgery outcomes database between August 1, 2006, and June 15, 2012. The primary outcome was the presence or absence of a poor neurologic outcome 48 hours after surgery, with a modified Rankin scale score >2 being defined as a poor neurologic outcome. The neurologic outcome at the time of hospital discharge was a secondary outcome. Secondary outcomes related to cardiac morbidity included atrial or ventricular arrhythmia requiring treatment and elevated cardiac biomarkers consistent with ischemia (i.e., Troponin-I). RESULTS: During the study period, adenosine-induced flow arrest was used in 72 of the 413 patients (17.4%) who underwent intracranial aneurysm clip ligation. The difference in the incidence of poor neurological outcome, with or without the use of adenosine, was no larger than 15.7% at 48 hours after surgery (P =0.524) or -12.7% at discharge (P = 0.741). In addition, the difference in the incidence of cardiac morbidity was no larger than -16.0% for persistent arrhythmia (P = 0.155) or -9.4% for biomarkers of myocardial ischemia (P = 0.898) in the initial 48 hours after surgery. CONCLUSION: When used to facilitate intracranial aneurysm clip ligation, adenosine-induced flow arrest was associated with no more than a 15.7% increase or a 12.7% decrease in the incidence of a poor neurologic outcome at either 48 hours or at the time of hospital discharge. In addition, adenosine use was not associated with cardiac morbidity in the perioperative period (i.e., persistent arrhythmia or biomarkers of cardiac ischemia).
