Nahum Nesher

Ketamine spares morphine consumption after transthoracic lung and heart surgery without adverse hemodynamic effects.

BACKGROUND Thoracotomy is associated with severe pain. Large doses of morphine can depress respiratory drive and compromise hemodynamic stability. Ketamine reduces hyperalgesia, prevents opioid tolerance and resistance and lowers morphine consumption. At sub-anesthetic (< or = 500 microg/kg) doses, ketamine rarely produces undesirable hemodynamic alterations. We hypothesized that by combining a sub-anesthetic dose of ketamine with morphine, we could effectively control pain with less morphine and minimize drowsiness, while maintaining safe hemodynamic and respiratory parameters. METHODS Sequential patients undergoing anterolateral thoracotomy for MIDCAB, lung tumor resection, or median sternotomy for OPCAB were randomized to one of the two intravenous patient-controlled analgesia (IV-PCA) protocols. MO-only patients received 1.5 mg MO bolus, and MK patients received 1.0 mg MO+5 mg ketamine/bolus, both with a 7 min lockout time. IV-PCA was initiated when the patient was sufficiently awake (> or = 5/10 VAS) and rated pain > or = 5/10 on a 0-10 VAS. Rescue intramuscular diclofenac 75 mg was available. Follow-up of respiratory, hemodynamic and pain statuses lasted 72 h. RESULTS Fifty-eight patients completed the 6-month study. Heart rate and blood pressures were identically stable in both groups. Respiratory rate and pulse oximetry were higher (P < 0.05) in the MK than in the MO group. MO patients (n = 28) used twice (2.0 +/-2.3 mg/patient/h) the amount of morphine compared to MK patients (n = 30, 1.0 +/- 1.4 mg/patient/h, P < 0.05). Thirty-six hours after starting PCA, 10 MO patients still required IV-PCA compared to 5 MK patients (P < 0.05). Diclofenac was used 70% more in MO than in MK patients. MO patients suffered more postoperative nausea and vomiting. No patients had hallucinations. CONCLUSIONS The concomitant use of sub-anesthetic ketamine plus two-thirds the standard MO dose following thoracotomy, MIDCAB or OPCAB resulted in lower pain scores, reduced MO consumption and shorter postoperative IV-PCA dependence. These advantages were associated with cardiovascular stability and even better respiratory parameters.

Strict Thermoregulation Attenuates Myocardial Injury During Coronary Artery Bypass Graft Surgery as Reflected by Reduced Levels of Cardiac-Specific Troponin I

We assessed the cardioprotective effects of perioperative maintenance of normothermia by determining the perioperative profile of troponin I, a highly cardiac-specific protein important in risk stratification of patients with acute ischemic events. Candidates for their primary coronary artery bypass grafting (CABG) were randomized into a new thermoregulation system group, Allon( thermoregulation (AT; n = 30), and a routine thermal care (RTC; n = 30) group. Anesthetic and operative techniques were similar in both groups. Intraoperative warming was applied before and after cardiopulmonary bypass (CPB) and up to 4 h after surgery. Perioperative temperature and hemodynamic data were recorded. Blood samples for creatine kinase (CK) and its isoform, MB (CK-MB), and for cardiac-specific troponin I (cTnI) were obtained at predetermined intervals throughout the entire operation. Core and skin temperatures were higher in the AT group at all time points. The systemic vascular resistance was lower and the cardiac index higher in the AT group at all intra- and postoperative time points. Increases in CK, CK-MB, and cTnI levels indicated intraoperative ischemic insult in all patients. The respective CK levels for the AT and RTC groups were 53.3 +/- 22.7 IU/L and 47.9 +/- 17.86 IU/L at the time of anesthesia and 64.7 +/- 45.6 IU/L and 47.8 +/- 19.4 IU/L 30 min after the onset of surgery, demonstrating thereafter a steep increase before the discontinuation of CPB. CK-MB mass concentrations in both groups behaved almost identically. Pre-CPB cTnI levels at anesthesia induction were 0.3 +/- 0 ng/mL in both groups, followed by a distinctive profile observed after separation from CPB: 28.1 +/- 11.4 ng/mL, 26.05 +/- 9.20 ng/mL, and 22.3 +/- 8.9 ng/mL at discontinuation from CPB, chest closure, and 2 h after surgery, respectively, in the RTC group, versus 0.6 +/- 4.6 ng/mL, 6.6 +/- 5.5 ng/mL, and 7.9 +/- 4.76 ng/mL at these three time points, respectively, in the AT group (P < 0.01 between groups at the specified time points). Contrary to conventional thinking about the benefits of hypothermia, maintenance of normothermia throughout the non-CPB phases during CABG was demonstrated to be important in attenuating myocardial ischemic injury. Insofar as troponin I was more sensitive than other tested markers, it may provide important data on possible protection from myocardial insult and on other cardioprotective measures.

Effect of tumor necrosis Factor-Alphaon endothelial and inducible nitric oxidesynthase messenger ribonucleic acidexpression and nitric oxide synthesisin ischemic and nonischemic isolated rat heart

Abstract Objectives The present study aimed to investigate the influence of endogenous tumor necrosis factor-alpha (TNF-α) that was synthesized during ischemia and exogenous TNF-α on endothelial and inducible nitric oxide synthase (eNOS and iNOS) messenger ribonucleic acid (mRNA) expression and nitric oxide (NO) production in the isolated rat heart. Background Tumor necrosis factor-α is recognized as being a proinflammatory cytokine with a significant cardiodepressant effect. One of the proposed mechanisms for TNF-α-induced cardiac contractile dysfunction is increased NO production via iNOS mRNA upregulation, but the role of NO in TNF-α-induced myocardial dysfunction is highly controversial. Methods Isolated rat hearts studied by a modified Langendorff model were randomly divided into subgroups to investigate the effect of 1-h global cardioplegic ischemia or the effect of 1-h perfusion with exogenous TNF-α on the expression of eNOS mRNA and iNOS mRNA and on NO production. Results After 1 h of ischemia, there were significant increases in TNF levels in the effluent (from hearts), and eNOS mRNA expression had declined (from 0.91 ± 0.08 to 0.68 ± 0.19, p Conclusions We believe this is the first study to directly show that TNF-α does not increase NO synthesis and release but does downregulate eNOS mRNA in the ischemic and nonischemic isolated rat heart.

A novel thermoregulatory system maintains perioperative normothermia in children undergoing elective surgery

Background: Body heat loss during anaesthesia may result in increased morbidity, particularly in high‐risk populations such as children. To avoid hypothermia, a novel thermoregulatory system (Allon) was devised. We tested the safety and efficacy of this system in maintaining normothermia in children undergoing routine surgical procedures.

Repeat Median Sternotomy After Prior Ante-Aortic Crossover Right Internal Thoracic Artery Grafting

Abstract  Background: In situ bilateral internal thoracic artery (ITA), with ante‐aortic crossover right ITA (RITA) is gaining popularity. However, the retrosternal position of the crossover RITA has raised concerns with regard to its compromise during subsequent resternotomy. Methods: Ten patients underwent repeat median sternotomy after prior ante‐aortic crossover RITA grafting. Specific RITA routing and fixation had been performed in the initial operation. Preoperative imaging, including computed tomography (CT) angiography, was performed to confirm RITA position in relation to the sternum and assess feasibility. Results: Resternotomy was performed 4–48 months after the initial operation (median, 22 months). Nine crossover RITA grafts were functioning at the time of resternotomy. CT angiography was performed in four patients in whom the premarked RITA could not be localized on the plain chest radiograph. The feasibility of conducting a nonmodified resternotomy was determined based on preoperative imaging. All RITA grafts resumed their original position and none was injured during reentry. There was no early mortality, perioperative stroke, or reexploration for bleeding. One patient sustained myocardial infarction, however, not in a RITA‐related distribution. CT angiography was predictive in confirming a free retrosternal space. Conclusions: Resternotomy after prior ante‐aortic crossover RITA grafting can be performed at acceptable risk. Confirmation of a free retrosternal space by preoperative imaging may contribute to the safety of the procedure. Maneuvers performed during the first operation are useful in preventing RITA adherence to the sternum. (J Card Surg 2004;19:151‐154)

Impact of left ventricular filling parameters on outcome of patients undergoing trans-catheter aortic valve replacement.

Aim To assess the impact of left ventricular (LV) filling parameters on outcomes following trans‐catheter aortic valve replacement (TAVR). Methods and results A total of 526 TAVR patients were compared with 300 patients with severe aortic stenosis (AS) treated conservatively. Clinical variables were collected along with echocardiographic data at baseline, 1 month, and 6 months after study entry. End points included all‐cause mortality and the combination of death and heart failure admission. LV filling parameters associated with mortality included reduced A wave velocity (P = 0.005) and shorter deceleration time (DT) (P = 0.0005). DT was superior to all other parameters (P = 0.05) apart from patients with atrial fibrillation in whom E/e′ was better. Short DT (<160 ms) was associated with lower survival than long DT (≥220 ms; P = 0.002) or intermediate DT (P = 0.05), even after adjustment for age, gender, stroke volume index (SVI), and co‐morbidities. However, patients with short baseline DT exhibited greater improvement in DT, E/A, and systolic pulmonary pressure at follow‐up than patients with baseline DT ≥160 ms (P < 0.05 for all time x group interactions). Most importantly, among patients with short DT, TAVR was associated with better survival than conservative treatment (46 ± 7 vs. 28 ± 12% at 3 years, P = 0.05), even after adjustment for age, gender, and SVI (P = 0.05). Conclusion Short DT is an independent predictor of adverse outcome following TAVR. Nevertheless, LV filling parameters improve in most patients post TAVR, and TAVR is associated with improved survival compared with conservative therapy, even in patients with evidence of elevated LV filling. Thus, evidence of elevated LV filling should not be viewed as a contraindication for TAVR.

Should Bilateral Internal Thoracic Artery Grafting Be Used in Patients After Recent Myocardial Infarction

Background Bilateral internal thoracic artery grafting (BITA) is associated with improved survival. However, surgeons do not commonly use BITA in patients after myocardial infarction (MI) because survival is good with single internal thoracic artery grafting (SITA). We aimed to compare the outcomes of BITA with those of SITA and other approaches in patients with multivessel disease after recent MI. Methods and Results In total, 938 patients with recent MI (<3 months) who underwent BITA between 1996 and 2011 were compared with 682 who underwent SITA. SITA patients were older and more likely to have comorbidities (diabetes mellitus, chronic obstructive pulmonary disease, chronic renal failure, peripheral vascular disease), to be female, and to have had a previous MI. Acute MI and 3‐vessel disease were more prevalent in the BITA group. Operative mortality of BITA patients was lower (3.0% versus 5.8%, P=0.01), and sternal infections and strokes were similar. Median follow‐up was 15.21 years (range: 0–21.25 years). Survival of BITA patients was better (70.3% versus 52.5%, P<0.001). Propensity score matching was used to account for differences in preoperative characteristics between groups. Overall, 551 matched pairs had similar preoperative characteristics. BITA was a predictor of better survival in the matched groups (hazard ratio: 0.679; P=0.002; Cox model). Adjusted survival of emergency BITA and SITA patients was similar (hazard ratio: 0.883; P=0.447); however, in the nonemergency group, BITA was a predictor of better survival (hazard ratio: 0.790; P=0.009; Cox model). Conclusions This study suggests that survival is better with BITA compared with SITA in nonemergency cases after recent MI, with proper patient selection.

Comparison of radial and bilateral internal thoracic artery grafting in patients with peripheral vascular disease

OBJECTIVES The composite T-graft with radial artery (RA) attached end-to-side to the left internal thoracic artery (ITA) provides arterial myocardial revascularization without the increased risk of deep sternal wound infection associated with harvesting 2 ITAs. However, many surgeons are reluctant to use RA in patients with peripheral vascular disease (PVD) due to concerns regarding the quality of the conduit in this subset of patients. The purpose of this study is to compare early- and long-term outcomes of arterial grafting with bilateral ITAs (BITA) to that of single ITA and RA in patients with PVD. METHODS Between 1999 and 2010, 619 consecutive patients with PVD (500 BITAs and 119 single ITA and RA) underwent myocardial revascularization in our institution. RESULTS Occurrence of following risk factors as female sex, age 70+, diabetes, unstable angina, emergency operation, cerebrovascular disease and chronic obstructive pulmonary disease was higher in the RA-ITA group. The RA-ITA group also had a higher logistic EuroSCORE (22.1 vs 13.3). Operative mortality and occurrence of deep sternal wound infection of the two groups was similar (4.2% vs 5.0% and 2.5% vs 4.0% for the radial and bilateral ITA, respectively). Median follow-up was 9.75 years. Unadjusted Kaplan-Meier 10-year survival of the two groups was similar (44.1% vs 49.6%, P  = 0.7). After propensity score matching (100 pairs), assignment to BITA was not associated with better adjusted survival (hazard ratio 0.593, 95% confidence interval 0.265-1.327, P  = 0.20, Cox model). CONCLUSIONS In patients with PVD, complete arterial revascularization with left ITA and RA can be justified with regards to survival.

Thoracoscopic epicardial lead implantation as an alternative to failed endovascular insertion for cardiac pacing and resynchronization therapy.

ObjectiveNumerous anomalies or postprocedural stricture of the venous system prevent optimal endovascular implantation of a pacing lead in more than 10% of patient indicated for permanent pacing or cardiac resynchronization therapy. The purpose of this report was to summarize our experience and immediate postoperative results of thoracoscopic lead implantation as a lesser invasive solution to an unsuccessful endovascular lead insertion. MethodsFrom January 2008 to April 2013, 11 epicardial leads were introduced thoracoscopically at our center as a rescue treatment after failed endovascular attempts. Patients were ventilated using a double-lumen endotracheal tube. A 5-mm 30-degree lance thoracoscope was used with either 2 or 3 additional working ports. A screw-in pacing lead (Medtronic Model 5071 Pacing lead, Minneapolis, MN USA) was inserted into the left ventricular epicardium. After the lead placement and assessment for threshold less than 1 V, the lead was brought to the chest wall and tunneled to the pacemaker generator pocket. At the end of the procedure, a small, flexible 14F thoracic drain, was left inside the pleural cavity for the next 24 hours. ResultsThere were no mortality or any major surgical complications among these patients. All patients responded to the epicardial lead implantation in terms of appropriate pacing and conductivity. No clinical failure was observed, and no patient required a repeat procedure. ConclusionsThoracoscopic lead insertion is safe and easy to perform. We believe it should be offered as the first choice after failed endovascular pacing lead implantation.