A Double-Blind Randomized Controlled Trial Comparing Epidural Clonidine vs Bupivacaine for Pain Control During and After Lower Abdominal Surgery.

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.

A propensity-matched comparison of the incidence of new-onset postoperative atrial arrhythmias in cardiac and noncardiac thoracic surgery patients.

OBJECTIVE: The primary aim of this investigation was to compare the incidence of new-onset postoperative atrial arrhythmias (POAAs) in cardiac versus noncardiac thoracic surgery patients. A subgroup analysis also was performed in the cardiac surgery patients comparing POAAs in patients who underwent cardiac surgery on and off cardiopulmonary bypass (CPB). DESIGN: This was a retrospective study using the Department of Cardiothoracic Anesthesia patient registry. All patients (n = 33,500) undergoing cardiac (n = 29,057) and noncardiac thoracic (n = 4,443) surgeries between 1993 and 2004 were identified from the patient registry. Two propensity-matched comparisons for the incidence of POAAs were made: (1) in cardiac surgery patients versus noncardiac thoracic surgery patients and (2) in patients undergoing cardiac surgery with versus without CPB. SETTING: A large metropolitan multidisciplinary clinic. PARTICIPANTS: Patients. INTERVENTION: No interventions were done because this was a retrospective study. MEASUREMENTS AND MAIN RESULTS: The cardiac patients had a significantly higher incidence of POAAs when compared with noncardiac thoracic surgery patients (11.6% v 7.5%, p < 0.001). There was no significant difference in the incidence of POAAs between patients undergoing CPB versus off-pump CPB (13.3% v 12.3%, p = 0.3). CONCLUSION: The incidence of new-onset POAAs was higher in patients undergoing cardiac surgery than in patients undergoing noncardiac thoracic surgery in propensity-matched patient groups. CPB was not associated with new-onset POAAs.

Overdrive pacing for endovascular repair of an aortic arch aneurysm.

The endovascular treatment of aortic arch aneurysms is a relatively new technique and is associated with significant surgical and anesthetic challenges. We report a case of a 77-year-old patient with an aortic arch aneurysm at the level of the isthmus, measuring 4.9 x 6.5 cm. The aneurysm involved the origin of the left subclavian and vertebral arteries. The arch was of the bovine type and the left vertebral artery came directly off the aorta. The patient underwent an uneventful open left carotid-to-subclavian bypass several days before the aortic repair. During the endovascular surgery, a stent-graft was deployed just distal to the innominate trunk. Endoleak was noted at the inferior aspect of the stent-graft, which failed to seal with placement of an extension stent-graft. The surgeon then chose to employ a Palmaz stent, to seal the endoleak. Balloon expansion in the ascending aorta was required in order to properly seat the Palmaz stent. Overdrive pacing at a rate of 220 beats min(-1), which lowered the systolic blood pressure (SBP) to 40s mmHg was used during this process after connecting the patient to a Zoll defibrillator with external pads. The Palmaz stent was successfully deployed at the proximal end of the previously deployed stent-graft, using a Tyshak balloon. The patient reverted to normal sinus rhythm with no evidence of ischemia at the conclusion of the overdrive pacing. No endoleak was appreciated after the Palmaz stent was placed.

An 11-year, single-institution analysis of intra-aortic balloon pump use in cardiac surgery.

OBJECTIVES: The primary objective of this study was to analyze perioperative intra-aortic balloon pump (IABP) insertion in patients undergoing cardiac surgery in the authors' institution from 1995 to 2005 and to propose an explanation for changes in use over this period. A secondary objective was to assess patient variables associated with IABP use. DESIGN: This is a retrospective study including patients who underwent cardiac surgery between 1995 and 2005. SETTING: The Cardiothoracic Anesthesia Patient Registry of a single teaching institution was queried to obtain the required information. PARTICIPANTS: Thirty thousand two hundred sixty-nine cardiac surgery patients. INTERVENTIONS: Intra-aortic balloon pump insertion before surgery, after cardiopulmonary bypass, or in the cardiovascular intensive care unit was assessed in patients who underwent isolated coronary artery bypass graft surgery, valve surgery, or both. Select patient variables were analyzed for their association with IABP insertion. Transesophageal echocardiography (TEE) examinations, milrinone use, and mortality rates also were determined. MEASUREMENTS AND MAIN RESULTS: Among 30,269 cardiac surgery patients, 1,310 (4.32%) underwent IABP insertion. Combined preoperative, intraoperative, and postoperative IABP use decreased from 7.8% in 1995 to 3.0% in 2005. Simultaneously, the intraoperative use of milrinone increased from 4.8% to 8.8% and postoperative use increased from 5.2% to 7.8%. The number of intraoperative TEE examinations more than doubled from approximately 1,700 to 3,500. The overall mortality for patients with preoperative, intraoperative, and postoperative IABP insertion was 12.6%, 17.5%, and 47.7%, respectively. CONCLUSIONS: From 1995 to 2005, preoperative, intraoperative, and postoperative IABP use decreased by approximately 60% in cardiac surgery patients. Simultaneously, the use of TEE and milrinone each doubled. Although a cause-effect relationship cannot be established from the present study's observational data, the trends coincide and may be related.