Comparison between the Effects of Dexmedetomidine and Midazolam on Postoperative Cognitive Impairment after Coronary Artery Bypasses Graft Surgery: A Randomized Clinical Trial.

Background: Postoperative cognitive decline is a common complication observed frequently after general anesthesia in the immediate postoperative phase. We studied the effects of dexmedetomidine versus midazolam during coronary artery bypass graft (CABG) surgery on cognitive and memory function. Methods: In this clinical trial, 42 elective on-pump CABG candidates under general anesthesia, aged between 40 and 65 years, were enrolled randomly in 2 groups. Group A received 0.05-0.1 mg/kg of midazolam and Group B received 1 µg/kg of dexmedetomidine. One day before surgery, all the participants underwent the Persian version of the Mini-Mental State Examination (MMSE) and the Persian version of the Wechsler Memory Scale (WMS) test for a comparison of cognitive impairment and memory functions. Both groups were given fentanyl and propofol for the induction of anesthesia and muscle relaxants. The MMSE and WMS tests were repeated 5 and 30 days after surgery. Results: The mean±SD of age was 55.47±7.18 y in Group A and 55.39±6.08 y in Group B. Eighty percent of the participants were men in both groups. There were no significant differences between Group A and Group B in the MMSE and WMS before surgery (89.04±14.30 vs. 97.10±18.10, respectively; P=0.059), but the WMS was significantly different 30 days after surgery (87.60±14.30 vs. 103.53±19.93, respectively; P=0.005). Group A showed high cognitive impairment and low WMS scores compared with Group B (P=0.005). Additionally, the MMSE results were not statistically different between the 2 groups postoperatively (24.80±3.18 vs. 23.55±4.18, respectively; P=0.394). Conclusion: Our results showed that dexmedetomidine might have a lower impact on cognitive function than might midazolam among patients undergoing CABG.

Left Brachiocephalic Vein Cannulation in Bicaval Venous Drainage Is Safe, Effective, and Technically Advantageous.

Direct cannulation of both venae cavae (bicaval venous cannulation) is the gold standard for right atrial isolation in intracavitary surgery, but there has been no consensus about an alternative site. Therefore, we studied an alternative method for bicaval venous drainage in which the left brachiocephalic vein (LBCV) is cannulated instead of the superior vena cava. From 2012 through 2014, we performed routine LBCV cannulation in 150 consecutive patients as part of bicaval venous drainage before right atrial isolation. We prospectively collected demographic information, operative data, total pump and LBCV cannula flows with their respective calculated and indexed rates, central venous pressures, and perioperative complications. All patients survived surgery. There were no adverse technical outcomes or functional deficits associated with the technique. The mean indexed LBCV cannula flow was 1,520 ± 216 mL/min/m(2), representing an LBCV cannula-to-calculated pump-flow ratio of 64%. The mean central venous pressure during right atrial isolation was 3.7 ± 1.9 mmHg. Cannulation of the LBCV is intrinsically a safe and reproducible procedure with proven hemodynamic adequacy. Its versatility can be an asset to surgical techniques and perfusion methods. Furthermore, the hemodynamic results in our series promise alternative intrathoracic and extracardiac cannulation sites for mini-extracorporeal circulation, on-pump beating-heart procedures, and short-term circulatory assist device implementation.

Esophageal stethoscope: an old tool with a new role, detection of residual flow during video-assisted thoracoscopic patent ductus arteriosus closure.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) has emerged as an innovative and popular procedure for closure of a patent ductus arteriosus (PDA), but is associated with a minute rate of residual or recurrent duct patency. This study aims to analyze the efficacy of intraoperative esophageal stethoscopic monitoring in reducing the incidence of residual ductal flow during PDA clipping by VATS. METHODS: Between June 1997 and October 2009, we retrospectively assessed 2000 consecutive patients with PDA who underwent VATS. During the procedure, heart sounds were monitored by the anesthesiologist through an esophageal stethoscope. Changes in continuous cardiac murmurs were recorded before and after the PDA clipping and were confirmed to disappear completely. Color flow Doppler echocardiography was performed immediately before discharge, and patients were followed monthly for 3, 6, and 12 months and then annually to confirm the absence of residual or recurrent shunt. RESULTS: Mean age was 6.0 years (range, 1 month-35 years), mean weight was 11.1 kg (range, 6-65 kg), and mean PDA diameter was 5.5 mm (range, 3-9 mm). Ninety-two percent of patients showed no ductal flow after a single clipping. In the other 8% of patients, residual flow was detected intraoperatively after a single clipping, but was eliminated by the second clipping. Twelve patients (0.6%) presented with residual ductal flow immediately after the operation (detected by color Doppler echocardiography), which was eliminated by thoracotomy before discharge. All patients left the hospital with echocardiography documenting no evidence of residual PDA. At follow-up, the incidence of residual patency was 0.2% (4 of 2000). CONCLUSIONS: Our results demonstrate that the intraoperative esophageal stethoscope provides a remarkably effective technique for monitoring and evaluating PDA ligation by VATS, thus avoiding reintervention and the complications associated with residual ductal flow in most cases.

Video-assisted ductal closure with new modifications: minimally invasive, maximally effective, 1,300 cases.

BACKGROUND: Video-assisted thoracoscopic surgery (VATS) has been shown to be a safe and effective method of closing patent ductus arteriosus (PDA). We retrospectively studied our series of patients with PDA who underwent VATS closure with new modifications. METHODS: From June 1997 to December 2004, 1,300 consecutive patients diagnosed with PDA (mean age, 6 years) were referred to us, and all of them met our inclusion criteria for the VATS procedure. Recently, we made some minor alterations to our routine methodology. After complete closure of PDA by two titanium clips, the extubated patient leaves the operating room without a chest tube. RESULTS: There were 3 cases of chylothorax, which were successfully treated by thoracotomy and ligation of the small lymphatic ducts after 1 week of close observation. The procedure was changed to thoracotomy in 7 patients. Meanwhile, 5 additional patients had transient recurrent laryngeal nerve dysfunction. All cases were reassessed immediately after the procedure, and followed for more than 7 years by control echocardiography. No significant complication or residual shunt was recorded during the follow-up period. Mean procedure time was about 10 +/- 2 minutes. All patients were discharged shortly after the procedure (about 20 hours). CONCLUSIONS: Based on this experience, VATS appears to be safer and more effective as well as having other advantages such as being simple to perform, quick, and comfortable for the patients. Furthermore, the cosmetic benefits also make it appropriate as an outpatient procedure.