Caffeic acid phenethyl ester (CAPE) supplemented St. Thomas' hospital cardioplegic solution improves the antioxidant defense system of rat myocardium during ischemia-reperfusion injury.

BACKGROUND AND AIM OF STUDY: Cardioplegic arrest remains the method of choice for myocardial protection in cardiac surgery. Caffeic acid phenethyl ester (CAPE) prevents lipid peroxidation induced by ischemia-reperfusion injury and has a potent antioxidant property. We investigated the advantages of CAPE supplemented cardioplegic solution (St. Thomas' Hospital cardioplegic solution No.: 2) on the antioxidant defense system of myocardium against ischemia-reperfusion injury. MATERIAL AND METHODS: Isolated rat hearts were mounted on a nonrecirculating type of Langendorff apparatus. The hearts were arrested for 60 min with cardioplegic solution given at 20-min intervals and then reperfused for 15 min. The hearts were divided into three groups. Cold saline (0.9%, 4 degrees C) in group 1, St. Thomas' Hospital solution in group 2 and CAPE added St. Thomas' Hospital solution in group 3 were used as the cardioplegic solution. Krebs-Henseleit buffer solution was used for reperfusion. The tissues were examined biochemically for oxidative stress. RESULTS: Significant differences among the three groups existed in tissue myeloperoxidase (MPO), catalase (CAT), Na+-K+ ATPase activity and in the concentrations of malonydealdehyde (MDA) and 3-nitrotyrosine (3-NT). Group 2 showed significant changes in MPO (P = 0.04), Na+-K+ ATPase enzyme activity (P = 0.02) and the levels of MDA (P = 0.004) and 3-NT (P = 0.01) in comparison with group 1. Group 3 efficiently reduced MDA levels (P = 0.004) and also led to significant decrease in levels of MPO (P = 0.006), 3-NT (P = 0.01) and Na+-K+ ATPase activity (P = 0.01) and increase in the level of CAT (P = 0.004) in comparison with group 1. Significant changes were also found in the levels of MDA (P = 0.03), MPO (P = 0.04) and CAT (P = 0.009) in comparison between groups 2 and 3. CONCLUSIONS: We demonstrated that the administration of CAPE into cardioplegic solutions improves the antioxidant defense system of rat heart during the ischemia-reperfusion injury.     

Two-suture fish-mouth end-to-side microvascular anastomosis with fibrin glue

The most decisive step during free tissue transfers and replantation surgery may be respected as microvascular anastomosis. The conventional end-to-side anastomosis technique with simple interrupted sutures is well established and proven to be successful. On the other hand, conventional technique can be time consuming and can cause vascular thrombosis, vessel narrowing, and foreign-body reactions. Search for a more rapid and secure alternative to conventional technique is carried on. In this study, we defined a new technique for end-to-side anastomosis with fish-mouth incisions and application of fibrin glue and compared our results with those we obtained with conventional end-to-side anastomosis. We evaluated end-to-side anastomosis of carotid arteries of a total number of 64 Wistar-Albino rats. In control group (n = 32), conventional anastomoses with 8 to 10 sutures were performed. In experimental group (n = 32), fish-mouth incisions were applied first on the recipient artery, followed by performing anastomosis with only 2 corner sutures and applying commercially available fibrin glue. Time taken to perform the anastomosis was significantly shorter with the experimental group (P = 0.001), whereas early and late patency and aneurysm rates were comparable to those achieved with control group. Histological evaluation did not point out any significant differences between the groups. We have defined a rapid and safe alternative technique of end-to-side anastomosis with the use of fibrin glue. This method may be an alternative especially where multiple anastomoses are required or where it is difficult to approach anastomotic line, as it is easily performed, rapid, safe, and not involving any complex equipments.     

N-Acetylcysteine for Preventing Pump-Induced Oxidoinflammatory Response During Cardiopulmonary Bypass

Purpose To investigate the effect of N-acetylcysteine on preventing pump-induced oxidoinflammatory response during cardiopulmonary bypass (CPB).Methods Forty patients undergoing coronary artery bypass grafting (CABG) were randomly divided into a study group (n = 20), given 50mgkg^–1 N-acetylcysteine intravenously for 3 days, and a control group (n = 20) given saline. Serum samples were collected for measurement of myeloperoxidase (MPO), malondialdehyde (MDA), interleukin-6, ₁-acid glycoprotein (AAGP), and C-reactive protein (CRP) during surgery and postoperatively.Results The MPO and MDA values showed a similar pattern during and after CPB in the study group, with significantly less variance than in the control group. Interleukin-6 showed similar patterns in the two groups, but the data from 30min after the start of CPB and from 6h post-CPB were significantly different. The AAGP and CRP values were both elevated during CPB in the two groups without a significant difference, but 6 and 24h post-CPB, the values were significantly higher in the control group than in the study group.Conclusions N-Acetylcysteine decreased pump-induced oxidoinflammatory response during CPB, suggesting that it could be a novel therapy for assisting in the prevention of CBP-induced oxidoinflammatory damage.     

Is there a way to avoid surgical complications of twist drill craniostomy for evacuation of a chronic subdural hematoma?

Summary Background. Although twist drill craniostomy for evacuation of a chronic subdural hematoma is a rapid and minimally invasive procedure, it carries the risk of complications because it is a ‘blind’ technique. Our aim was to analyse the complications in a series of patients treated by this technique in order to identify methods of avoidance by modifications in the surgical technique. Method. Thirty-nine patients with a chronic subdural hematoma underwent twist drill craniostomy between November 2002 and December 2005 in our clinic. When a surgical complication happened we modified our surgical technique to see if this avoided it in future patients. Findings. Surgical complications happened in 7 patients (17.9%) including inadequate drainage, brain penetration, acute epidural hematoma and catheter folding. After preventive modifications these complications did not recur. Conclusions. Modifications in the technique of twist drill craniostomy are described in this paper which may minimise the occurrence of surgical complications.     

Risk factors of catheter-related bloodstream infections in parenteral nutrition catheterization

BACKGROUND: Intravascular catheters are integral to the practice of modern medicine. Potential risk factors for catheter-related bloodstream infection (CRBSI) include underlying disease, method of catheter insertion, and duration and purpose of catheterization. The administration of parenteral nutrition (PN) through intravascular catheters increases CRBSI risks. The purpose of this study was to evaluate the risk factors of CRBSI in patients with PN administration. METHODS: This study was conducted at the Karadeniz Technical University Hospital between October 2003 and November 2004. All the patients to whom PN was administered through intravascular catheters were prospectively monitored for the presence of CRBSI and risk factors. RESULTS: During the study period, 111 intravascular catheters through which PN was administered were monitored for a total of 1646 catheter-days. CRBSI was determined in 31 cases, a CRBSI rate of 18.8 per 1,000 catheter-days. When risk factors affecting CRBSI were investigated using logistic regression, an increase in APACHE II score (OR, 1.10; 95% CI, 1.01-1.21; p = .012), prolongation of catheterization (OR, 1.08; 95% CI, 1.02-1.14; p = .004), catheterization in emergent conditions (OR, 5.45; 95% CI, 1.20-24.82; p = .016), and poor patient hygiene (OR, 4.38; 95% CI, 1.39-13.78; p = .019) were all determined to be independent risk factors. Proper implementation of hand hygiene and maximal barrier precautions during the insertion of catheters reduced CRBSI levels (OR, 0.28; 95% CI, 0.09-0.88; p = .003 and OR, 0.26; 95% CI, 0.08-0.93; p = .017, respectively). CONCLUSIONS: It was concluded that the duration of catheterization should be shortened; that the intravascular catheter, which is inserted in urgent situations, should be removed as soon as possible; and that maximal sterile barrier precautions should be taken and due attention should be paid to hand hygiene.     

Comparison and evaluation of experimental mediastinitis models: precolonized foreign body implants and bacterial suspension inoculation seems promising

Background  

Post-sternotomy mediastinitis (PSM) is a devastating surgical complication affecting 1–3% of patients that undergo cardiac surgery. Staphylococcus aureus is one of the most commonly encountered bacterial pathogen cultured from mediastinal samples obtained from patients with PSM. A component of the membrane of the gram positive bacteria, lipoteichoic acid, stimulates the blood monocytes and macrophages to secrete cytokines, radicals and nitrogen species leading to oxido-inflammatory damage. This seems to be responsible for the high mortality rate in PSM. For the evaluation of the pathogenesis of infection or for the investigation of alternative treatment models in infection, no standard model of mediastinitis seems to be available. In this study, we evaluated four mediastinitis models in rats.     

Combined therapy of teicoplanin and caffeic acid phenethyl ester (CAPE) in the treatment of experimental mediastinitis in the rat

Post-sternotomy mediastinitis affects 1-3% of patients undergoing cardiac surgery and is lethal in 10-47% of these patients. We investigated the effect of an antioxidant/anti-inflammatory agent, caffeic acid phenethyl ester (CAPE), in the attenuation of inflammatory response induced by methicillin-resistant Staphylococcus aureus (MRSA) infection in a rat experimental mediastinitis model. Rats, divided into six equal groups, received MRSA precolonized stainless steel wire pieces implanted into their mediastinal spaces. Control group and CAPE control group received saline and CAPE 10 micromol/kg.day(-1 )respectively, where Group A received a single dose of teicoplanin 24 mg/kg i.m. for the first day and then 12 mg/kg.day(-1) . Group B received teicoplanin as in Group A plus CAPE 10 micromol/kg. day(-1 )intra-peritoneally. Group C received teicoplanin 60 mg/kg i.m. for the first day and then 30 mg/kg.day(-1 )and Group D received teicoplanin as in Group C plus CAPE 10 micromol/kg.day(-1) . By the end of 14 days rats were sacrificed and serum malondialdehyde (MDA), myeloperoxidase (MPO), nitric oxide (NO), urea and creatinine levels were evaluated. Mediastinal organ tissues were collected for histopathological analysis. Infection rates in all the drug-treated groups were lower than the control groups ( P=0.002) but statistical significance was attained only between the groups A and D ( P=0.018). In connective tissues and the peribronchial area polymorphonuclear leukocytic (PNL) infiltration in the treatment groups, although becoming very close, did not reach statistical significance (P =0.053, P=0.075, respectively). PNL infiltration especially in the peribronchial tissues of the Group B animals was found to be significantly less than the Control and CAPE Control groups with P values of 0.013 and 0.010, respectively. MDA and MPO levels were significantly lower in the treatment groups ( P<0.001 and P<0.001 respectively). Levels of the degradation products of NO were lower in treatment groups compared to two control groups (P=0.003, P= 0.005). NO levels in Group D were lowest among all treatment groups ( P=0.001). It has been demonstrated that although bacterial colonization can be controlled in mediastinitis, the inflammatory response persists. The combination of an antioxidant / anti-inflammatory agent, CAPE, added to standard antibiotic therapy might be effective in the treatment of post-sternotomy mediastinitis due to MRSA.