Engin Erturk

Comparison of the effect of propofol and N-acetyl cysteine in preventing ischaemia-reperfusion injury

Background and objective The aim of this study was to compare the effects of propofol and N-acetyl cysteine (NAC) on tourniquet-induced ischaemia–reperfusion injury by determining malonyldialdehyde, ischaemia-modified albumin, lactate, blood gas and haemodynamic levels in arthroscopic knee surgery. Methods Sixty ASA I or II patients were randomized into three groups. Intrathecal anaesthesia was administered using 0.5% heavy bupivacaine in all patients. In group P, propofol was administered in a 0.2 mg kg−1 bolus, followed by infusion at a rate of 2 mg kg−1 h−1; in group NAC, NAC was administered as an infusion at a rate of 5 mg kg−1 h−1, and, in group C (the control group), an equal volume of isotonic saline was administered to patients until 30 min after reperfusion. Blood samplings were obtained immediately before intrathecal anaesthesia (t1), 1 min before tourniquet release (t2), 5 min after tourniquet release (t3) and 30 min after tourniquet release (t4). Results Plasma malonyldialdehyde, ischaemia-modified albumin and lactate levels increased significantly in group C at t3 and t4 compared with the baseline values. Plasma concentrations of malonyldialdehyde, ischaemia-modified albumin and lactate in groups P and NAC were significantly lower than those in group C at t3 and t4. In blood gas analyses, pH, HCO3 and base excess were found to be significantly lower at t3 and t4 compared with t1 and t2 in group C. Comparisons between groups P and NAC revealed no significant differences. Conclusion Small-dose infusions of both propofol and NAC appear to provide similar protection against ischaemia–reperfusion injury in arthroscopic knee surgery.

The Comparison of the Effects of Sevoflurane Inhalation Anesthesia and Intravenous Propofol Anesthesia on Oxidative Stress in One Lung Ventilation

Background. The aim of this study is to compare the effects of sevoflurane and propofol on one lung ventilation (OLV) induced ischemia-reperfusion injury (IRI) by determining the blood gas, ischemia-modified albumin (IMA), and malonyldialdehyde (MDA). Material and Methods. Forty-four patients undergoing thoracic surgery with OLV were randomized in two groups (sevoflurane Group S, propofol Group P). Anesthesia was inducted with thiopental and was maintained with 1–2.5% of sevoflurane within the 40/60% of O2/N2O mixture in Group S. In Group P anesthesia was inducted with propofol and was maintained with infusion of propofol and remifentanil. Hemodynamic records and blood samples were obtained before anesthesia induction (t 1), 1 min before two lung ventilation (t 2), 30 min after two lung ventilation (t 3), and postoperative sixth hours (t 4). Results. Heart rate at t 2 and t 3 in Group P was significantly lower than that in Group S. While there were no significant differences in terms of pH and pCO2, pO2 at t 2 and t 3 in Group S was significantly lower than that in Group P. IMA levels at t 4 in Group S were significantly lower than those in Group P. Conclusion. Sevoflurane may offer protection against IRI after OLV in thoracic surgery.

A comparison of levobupivacaine and levobupivacaine-tramadol combination in bilateral infraorbital nerve block for postoperative analgesia after nasal surgery.

BackgroundOur aim in this study was to investigate the effect of levobupivacaine and a levobupivacaine + tramadol combination on postoperative analgesia in intraoperative nerve block under standard general anesthetic. MethodsForty-five patients undergoing outpatient nasal surgery under general anesthesia were randomized into 3 groups. Group L: 0.25% levobupivacaine, group T: 0.25% levobupivacaine and 50 mg tramadol, group S: normal saline solution; 2 mL of each being injected into the infraorbital foramen. Intraoperative hemodynamic changes were recorded. Verbal numeric rating scale (NRS) values were checked at 30 minutes and 1, 2, 8, and 12 hours postoperatively, and the need for rescue analgesic treatment in the first 12 hours of all patients was recorded. Also antiemetic drug requirement and side effects (nausea, edema, erythema, hematoma, and sedation) were recorded. ResultsAt 30 minutes and 1 hour postoperatively, NRS pain scores were lower in group T than in group S (P < 0.0001, P = 0.01, respectively). NRS pain score was lower in group T compared with group L at 1 hour postoperatively (P = 0.01). Effective analgesia time (sec) in the control group (142.67 ± 77.31) was shorter than levobupivacaine (240 ± 96.39) and levobupivacaine added to tramadol groups (277 ± 11.60) (P < 0.05). Additional analgesic requirement in the control group was higher than the other 2 groups in early postoperative period (P < 0.05). ConclusionsBilateral infraorbital nerve block with 0.25% levobupivacaine is an effective, reliable, and simple technique in the treatment of postoperative pain in nasal surgery. In addition, the addition of tramadol as an adjuvant to local anesthetics in this technique is safe.

Ischemia-Reperfusion Injury and Volatile Anesthetics

Ischemia-reperfusion injury (IRI) is induced as a result of reentry of the blood and oxygen to ischemic tissue. Antioxidant and some other drugs have protective effect on IRI. In many surgeries and clinical conditions IRI is counteract inevitable. Some anesthetic agents may have a protective role in this procedure. It is known that inhalational anesthetics possess protective effects against IRI. In this review the mechanism of preventive effects of volatile anesthetics and different ischemia-reperfusion models are discussed.

Clinical Comparison of 12 mg Ropivacaine and 8 mg Bupivacaine, Both with 20 µg Fentanyl, in Spinal Anaesthesia for Major Orthopaedic Surgery in Geriatric Patients

Objective: The aim of this study was to compare the haemodynamic and anaesthetic effects of 12 mg ropivacaine and 8 mg bupivacaine, both with 20 µg fentanyl, in spinal anaesthesia for major orthopaedic surgery in geriatric patients. Subjects and Methods: Sixty American Society of Anesthesiologists (ASA) II–III patients scheduled for hip arthroplasty were randomly assigned to receive an intrathecal injection of either 12 mg ropivacaine with 20 µg fentanyl (group R, aged 70 ± 7 years, range 67–89) or 8 mg hyperbaric bupivacaine with 20 µg fentanyl (group B, aged 69 ± 6 years, range 66–92). Motor and sensory block, haemodynamics and side effects were recorded. Results: Mean levels of sensory block were similar, but the onset time of sensory block in group B (2.52 ± 0.69 min) was shorter than that in group R (3.17–0.72 min); the difference was statistically significant (p < 0.01), and the number of patients who had motor Bromage scale 3 in group B (24) was greater than in group R (16). The difference was also statistically significant (p < 0.05). Systolic and diastolic arterial pressures (SAP, DAP) and heart rate (HR) decreased after the block in both groups. SAP (after the 60th and 120th min of block), DAP (all measurement times), and HR (after the 20th, 25th and 30th min of block) were lower in group B than in group R. Conclusions: The data showed that 12 mg of ropivacaine and 8 mg of bupivacaine with 20 µg fentanyl in spinal anaesthesia can provide sufficient motor and sensory block for major orthopaedic surgery in geriatric patients. However, ropivacaine caused less motor block and haemodynamic side effects than bupivacaine during the procedure.

Dexmedetomidine acts as an oxidative damage prophylactic in rats exposed to ionizing radiation

STUDY OBJECTIVE To investigate the effects of dexmedetomidine on oxidative injury caused by ionizing radiation. DESIGN Randomized controlled experimental study. SETTING Department of radiation oncology and research laboratory of an academic hospital. INTERVENTIONS Twenty-eight rats were randomized to 4 groups (n=7 per group). Group S rats were administered physiologic serum; group SR rats were administered physiologic serum and 10 Gy external ionizing radiation. Groups D100 and D200 were administered 100 and 200 μg/kg dexmedetomidine intraperitoneally, respectively, 45 minutes before ionizing radiation. MEASUREMENTS Liver, kidney, lung, and thyroid tissue and serum levels of antioxidant enzymes (glutathione peroxidase [GPX], superoxide dismutase, and catalase) and oxidative metabolites (advanced oxidation protein products, malondialdehyde, and nitrate/nitrite, and serum ischemia-modified albumin) were measured 6 hours postprocedure. MAIN RESULTS In group SR, IR decreased antioxidant enzyme levels and increased oxidative metabolite levels (P<.05). In plasma, antioxidant enzyme levels were higher and oxidative metabolite levels were lower in groups D100 and D200 than in group SR (P<.01). In tissues, hepatic and lung GPX levels were higher in groups D100 and D200 than in group SR (P<.001). Renal and thyroid GPX levels were higher in D200 than in group SR (P<.01). Thyroid superoxide dismutase levels were higher in groups D100 and D200 than in group SR (P<.01). Renal, lung, and thyroid catalase levels were higher in group D200 than in group SR (P<.01). Hepatic, renal, and lung advanced oxidation protein products and malondialdehyde levels were lower in groups D100 and D200 than in group SR (P<.01). Hepatic, renal, and lung nitrate/nitrite levels were lower in group D200 than in group SR (P<.05). CONCLUSIONS Dexmedetomidine preserves the antioxidant enzyme levels and reduces toxic oxidant metabolites. Therefore, it can provide protection from oxidative injury caused by ionizing radiation.

Use of dexmedetomidine to prevent pulmonary injury after pneumoperitoneum in ventilated rats.

Purpose: This study examined the effectiveness of dexmedetomidine in preventing lung injury resulting from pneumoperitoneum in a ventilated rat model. Methods: Animals (n=18) were allocated randomly into 3 groups: control group, no pneumoperitoneum; sham group, pneumoperitoneum with intra-abdominal pressure of 12 mm Hg for 60 minutes; and dexmedetomidine group, dexmedetomidine administration 30 minutes before pneumoperitoneum. The rats were rested for 30 minutes after abdominal deflation. Then, blood samples were obtained for plasma malondialdehyde and ischemia-modified albumin (IMA) analyses. Tissue samples were taken for histopathologic examination and malondialdehyde analysis. Results: Compared with the control group, the sham group had a significantly higher level of plasma IMA. Pretreatment with dexmedetomidine significantly reduced the IMA level. Histopathologically, tissues from sham rats exhibited moderate or severe tissue damage, compared with control tissues. Dexmedetomidine-treated rats showed significantly less tissue damage than sham rats. Conclusions: Dexmedetomidine prophylaxis resulted in significantly less IMA production and significantly less neutrophil infiltration, thereby helping to protect the lungs from injury after pneumoperitoneum.

Conservative Management of Chylothorax after Coronary Artery Bypass Grafting

Chylothorax is a rare sequela to cardiac surgery, associated with high rates of morbidity and mortality. There are various medical and surgical options for its management. We describe 2 cases of chylothorax that developed after coronary artery bypass grafting and were managed successfully with medical therapy alone. Conservative treatment such as we describe aims to reduce chyle flow, to drain the pleural cavity in an effective manner, and to prevent chronic sequelae. Optimal conservative treatment, consisting of nothing by mouth and the administration of a pleurodetic agent, should be started immediately upon diagnosis. In most cases, it reduces the need for reoperation and long-term hospitalization. Prospective randomized controlled trials are nonetheless needed to confirm these assumptions.

Epidural Analgesia and Vaginal Delivery in a Patient with Aortic Stenosis and Insufficiency

Objective: To report a successful vaginal delivery using slow infusion of epidural analgesia in a patient with both severe aortic stenosis and insufficiency. Clinical Presentation and Intervention: A 26-year-old primigravid patient presented to our hospital for delivery. She had aortic stenosis and insufficiency due to rheumatic fever. Although the obstetrician recommended cesarean section owing to her cardiac status, she insisted upon vaginal delivery. We performed low-dose epidural analgesia with 10 ml of 0.125% ropivacaine and 20 µg fentanyl. She had spontaneous vaginal delivery without complication. Conclusion: This case showed that in spite of the cardiac pathology, vaginal delivery under low-dose slow infusion of epidural analgesia was successful and therefore may be a safe alternative to cesarean section for cardiac patients.

Regional Anesthesia for Postoperative Pain Control

Pain is an outstanding problem after surgical trauma. Pain following surgery may initiate variety of mechanisms including inflammatory, visceral, or somatic in origin and may persist to be chronic pain if improperly treated. The incidence of postoperative pain has been reported to be as higher as 60%, and, despite intensive effort, it is not able to resolve completely [1]. Most of the surgeries become less invasive and are increasingly being outpatient-based in time dependent manner. Besides technical developments on surgery, this tendency is mainly dependent on effective pain control and reduction of the side effects related to the treatments. Opioids and nonsteroidal anti-inflammatory drugs are the other main components of pain therapy which have well-known side effects that may limit their use. The modern concept of pain treatment includes multimodal approach and mainly targets to decrease opioid use in combination with other drugs or techniques in order to reduce drug related side effect profile especially to prevent postoperative respiratory depression. Until recently, there is no convincing data to demonstrate the beneficial effects of regional anesthesia on postoperative mortality, cardiovascular complications, or the incidence of thromboembolism when thromboprophylaxis is concomitantly in use, but all authors indicate that it may decrease the morbidity including postoperative pulmonary complications after major abdominal surgery and may improve the patient recovery after orthopedic surgery. It is also demonstrated that regional anesthesia reduces the incidence of postoperative pain, opioid consumption, and related side effects such as nausea and vomiting [2]. Central neuraxial blocks alone or in combination with catheter techniques are performed in various surgical interventions in order to decrease surgically induced stress and inflammation, improve pulmonary functions, and reduce the period for ambulation with better pain control. In a meta-analysis, it has been stated that postoperative pain control with local anesthetic infusion with long term catheter placement demonstrated a decrease in the occurrence of chronic pain [3]. Peripheral nerve blocks are the other type of regional techniques. Improvement in ultrasound technology may increase clinical applications for peripheral nerve and truncal blocks. Real time ultrasound use while performing the block may reduce the complications, performance time, and local anesthetic requirements. It also provides reappraising the older techniques with carrying potential complications. The rate of success may increase with clinical experience. Peripheral nerve blocks seem to lack systemic side effect related to sympathetic blockade and lesser incidence of minor complications including urinary retention when compared with central neuraxial blocks or catheter applications. Peripheral nerve blocks seem to be safer than either central neuraxial blocks or general anesthesia, especially in patients with severe coexisting disease [2]. In this special issue, we focused on the clinical studies and review articles related to various aspects of regional anesthesia for postoperative pain control. Some of these studies have investigated the effects of additives combined with local anesthetic mixture on postoperative analgesia in regional intravenous anesthesia. One of these reports investigated two additives, namely, ketamine or tramadol, combined with ropivacaine. While onset and duration of motor and sensorial block were shorter, the period of analgesia was longer in the tramadol group in the paper entitled “Does the addition of tramadol and ketamine to ropivacaine prolong the axillary brachial plexus block?” On the same topic, the efficacy on nitroglycerine or lornoxicam combination with lidocaine for regional intravenous anesthesia was searched. Each of these drug combinations effectively increased the tolerance to the tourniquet and decreased pain during peri- and postoperative period, which is discussed in the paper entitled “Peri- and postanalgesic properties of lidokain, lornoxicam, and nitroglycerine combination at intravenous regional anesthesia.” Likewise, dexketoprofen or paracetamol combination with lidocaine was compared to each other for the same purpose. Addition of dexketoprofen increased the duration of motor block and decreased pain scores, and lesser analgesic consumptions were observed in groups with paracetamol or dexketoprofen when compared with the control, in the paper entitled “Comparison of the effect of lidocaine adding dexketoprofen and paracetamol in intravenous regional anesthesia.” Central neuraxial blocks including spinal and epidural anesthesia were the subjects of the other studies. The effects of intraoperative intravenous magnesium sulfate infusion on sensorial and motor block characteristics and postoperative pain scales in female patients undergoing abdominal hysterectomy under spinal anesthesia were investigated. Authors indicated that the sensorial block period of spinal anesthesia increased, and better pain scores were observed with magnesium therapy without significant complications, in the paper entitled “The effect of intravenous magnesium sulfate infusion on sensory spinal block and postoperative pain score in abdominal hysterectomy.” In the other report, the difference of spinal block characteristics with levobupivacaine 0.5% plain solution at room and body temperature (23°C and 37°C) was observed in male patients undergoing transurethral resection of prostate operation. Authors indicated that the use of 0.5% levobupivacaine spinal anesthesia heated to the body temperature accelerated the start of sensory and motor block in the paper entitled “The effects on sensorial block, motor block, and haemodynamics of levobupivacaine at different temperatures applied in the subarachnoid space.” Epidural anesthesia was the main topic for postoperative pain control in two clinical trials. The influence of preemptive local anesthetic infusion with a thoracic epidural catheter on thoracotomy was evaluated and the effects of preemptive and postoperative infusions were compared. It was shown that preemptive administration of local anesthetic solution offered superior analgesic quality and lesser analgesic consumption, which is shown in the paper entitled “The effectiveness of preemptive thoracic epidural analgesia in thoracic surgery.” In a retrospective study, the difference of analgesic efficacy of epidural anesthesia was compared with total intravenous anesthesia performed with propofol and remifentanil infusion in patients who underwent abdominal aortic aneurysm repair. It was stated that the quality of analgesia improved with epidural anesthesia, and enteral nutrition was performed earlier, in the paper entitled “Efficacy of continuous epidural analgesia versus total intravenous analgesia on postoperative pain control in endovascular abdominal aortic aneurysm repair: a retrospective case-control study.” Caudal anesthesia is commonly performed in pediatric patients for surgical anesthesia and postoperative analgesia. In a clinical report entitled “The effects of single-dose rectal midazolam application on postoperative recovery, sedation, and analgesia in children given caudal anesthesia plus bupivacaine,” the effects of rectal midazolam combined with caudal anesthesia on the quality of sedation and postoperative analgesia were investigated, but no significant contribution was demonstrated. Gabapentin, a drug that is used for treatment of neuropathic pain, has also been investigated for possible effects on postoperative analgesia. In a review entitled “Gabapentin in acute postoperative pain management,” the influence of gabapentin treatment on postoperative pain control was documented and it was found that gabapentin was an efficacious agent for postoperative analgesia in various types of surgery. Pain is a common problem in all age groups of patients. Postoperative analgesia is a developing area and regional anesthesia is an essential part of this treatment. It is worthy of noting that future studies and technical developments about regional anesthesia will contribute vital advancements to postoperative pain control. Ahmet Eroglu Engin Erturk Alparslan Apan Urs Eichenberger Ozgun Cuvas Apan