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Dive into the research topics where George Vretzakis is active.

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Featured researches published by George Vretzakis.


Anesthesia & Analgesia | 2005

Prophylactic intravenous ondansetron and dolasetron in intrathecal morphine-induced pruritus: a randomized, double-blinded, placebo-controlled study.

Christos Iatrou; Christos Dragoumanis; Theodosia Vogiatzaki; George Vretzakis; Constantinos Simopoulos; V. Dimitriou

Pruritus is the most common side effect of intrathecal morphine for postoperative pain relief. Activation of central 5-hydroxytryptamine subtype 3 (5-HT3) receptors is one of its possible mechanisms. The role of 5-HT3 antagonists in the prevention of pruritus has not been clearly established. In a prospective, randomized, double-blind, placebo-controlled study, we evaluated the efficacy of prophylactic administration of ondansetron and dolasetron for the prevention of intrathecal morphine-induced pruritus. The patients were randomized into 3 groups to receive either 4 mg ondansetron IV (group O, n = 35), 12.5 mg dolasetron IV (group D, n = 35) or 5 mL placebo (group P, n = 35) 30 min before administration of spinal anesthesia with 10 to 17.5 mg of 0.5% hyperbaric bupivacaine and 0.25 mg of morphine for urologic, orthopedic, or vascular surgery. Patients were evaluated for incidence and severity of pruritus at arrival to the postanesthesia care unit and at 2, 4, 8, and 24 h postoperatively. The incidence and severity of pruritus was significantly less frequent in the ondansetron and dolasetron groups compared with placebo (34%, 20%, and 66% respectively, P < 0.01). Patients who received 5-HT3 antagonist reported significantly less total severity of pruritus compared with placebo during the first 8 h and the severe pruritus was observed only in patients within P group (P group: 4 of 35; 11%, O or D group: 0 of 35; 0%, P < 0.05). We conclude that the prophylactic use of ondansetron and dolasetron helps to reduce the incidence and severity of intrathecal morphine-induced pruritus.


Anesthesia & Analgesia | 2008

Endobrochial blockade through a tracheostomy tube for lung isolation.

George Vretzakis; Elena Theodorou; Dimitrios Mikroulis

We present an alternative technique for one-lung ventilation as safe way of treating patients with tracheostomy using a fiberoptic bronchoscope and a Fogarty catheter.


Anesthesiology Research and Practice | 2015

Depth of Anesthesia as a Risk Factor for Perioperative Morbidity

Argyro Petsiti; Vassilios Tassoudis; George Vretzakis; Dimitrios Zacharoulis; Konstantinos Tepetes; Georgia Ganeli; Menelaos Karanikolas

Introduction. The prognostic value of age, physical status, and duration of surgery on perioperative course has been extensively studied. However, the impact of deep hypnotic time (time when Bispectral Index values are less than 40) has not been well evaluated. Methods. We designed an observational study to clarify the relative influence of deep hypnotic time (DHT) on outcome. Eligible participants were mentally stable patients over 18 years old scheduled for elective major abdominal surgery. In total, 248 patients enrolled. Data were analyzed using Fishers exact test and multiple logistic regression. Results. Five variables (DHT, hypotension, age, comorbidity, and duration of surgery) showed statistically significant association with complications, when examined independently. However, when all variables were examined together in a multiple logistic regression model, age and comorbidity were no longer associated with outcome. DHT, hypotension, and duration of surgery were significant predictors of “complications,” and “hypotension” was a significant predictor of prolonged hospital stay (P < 0.001).  Conclusion. Deep hypnotic time emerged as a new factor associated with outcome, and its impact compared to other factors such as age, surgery duration, hypotension, and comorbidity is redefined. Monitoring and managing depth of anesthesia during surgery are important and should be part of careful operation planning.


Korean Journal of Anesthesiology | 2013

Peripheral nerve blockade as an exclusive approach to obturator nerve block in anterior cruciate ligament reconstructive surgery

Marina Simeoforidou; Meraxia Bareka; George Konstantinos Basdekis; Katerina Tsiaka; Eleni Chantzi; George Vretzakis

Background Obturator nerve block plays an additive role on the quality of analgesia for knee surgery. Since the use of dual guidance increases the success rate of nerve blocks, we investigated the feasibility of performing anterior cruciate ligament reconstruction under dual-guided blockade of obturator with femoral and sciatic nerves. Furthermore, we propose a novel method for the assessment of obturator nerve block. Methods Fifty-seven patients undergoing anterior cruciate ligament repair were studied. Neurostimulating needles were guided out-of-plane by ultrasound. To induce the obturator nerve block, 10 ml of ropivacaine 0.5% were injected after eliciting contractions of adductor longus, brevis and magnus followed by block assessment for 30 minutes by examining the patient lift and left down the leg. Results The sonographic recognition of obturator nerve was easy and quick in all cases. Time for applying the block was 119.9 ± 79.2 sec. Assessing this block with lifting-leaving down the leg gave satisfactory results in 24.0 ± 5.07 min. After performing femoral-sciatic blocks, the inflation of tourniquet resulted in VAS score of > 0 in 2/57 patients and operation in 12/57. Total dose of fentanyl was 120.1 ± 64.6 µg and of midazolam 1.86 ± 0.8 mg. In 6 patients propofol was administered for sedation and 1 of them required ventilation with laryngeal mask airway, converting the anesthesia technique to general anesthesia. Conclusions Our data suggest that anterior cruciate ligament reconstruction can be performed under obturator-femoral-sciatic blocks. Identification of obturator nerve with ultrasound is easy and the block can be assessed by observing how the patient lifts and leaves down the leg.


Anesthesiology Research and Practice | 2017

Pregabalin Effect on Acute and Chronic Pain after Cardiac Surgery

Aik Bouzia; Vassilios Tassoudis; Menelaos Karanikolas; George Vretzakis; Argyro Petsiti; Nikolaos Tsilimingas; Elena Arnaoutoglou

Introduction. Pain after cardiac surgery affects long-term patient wellness. This study investigated the effect of preoperative pregabalin on acute and chronic pain after elective cardiac surgery with median sternotomy. Methods. Prospective double blind study. 93 cardiac surgery patients were randomly assigned into three groups: Group 1 received placebo, Group 2 received oral pregabalin 75 mg, and Group 3 received oral pregabalin 150 mg. Data were collected 8 hours, 24 hours, and 3 months postoperatively. Results. Patients receiving pregabalin required fewer morphine boluses (10 in controls versus 6 in Group 1 versus 4 in Group 2, p = 0.000) and had lower pain scores at 8 hours (4 versus 3 versus 3, p = 0.001) and 3 months (3 versus 2 versus 2, p = 0.000) and lower morphine consumption at 8 hours (14 versus 13 versus 12 mg, p = 0.000) and 24 hours (19.5 versus 16 versus 15 mg, p = 0.000). Percentage of patients with sleep disturbances or requiring analgesics was lower in the pregabalin group and even lower with higher pregabalin dose (16/31 versus 5/31 versus 3/31, p = 0.000, and 26/31 versus 16/31 versus 10/31, p = 0.000, resp.) 3 months after surgery. Conclusion. Preoperative oral pregabalin 75 or 150 mg reduces postoperative morphine requirements and acute and chronic pain after cardiac surgery.


Journal of Anesthesia | 2014

Regional anesthesia for laparoscopic surgery: a narrative review

George Vretzakis; Metaxia Bareka; Diamanto Aretha; Menelaos Karanikolas

Laparoscopic surgery has advanced remarkably in recent years, resulting in reduced morbidity and shorter hospital stay compared with open surgery. Despite challenges from the expanding array of laparoscopic procedures performed with the use of pneumoperitoneum on increasingly sick patients, anesthesia has remained largely unchanged. At present, most laparoscopic operations are usually performed under general anesthesia, except for patients deemed “too sick” for general anesthesia. Recently, however, several large, retrospective studies questioned the widely held belief that general anesthesia is the best anesthetic method for laparoscopic surgery and suggested that regional anesthesia could also be a reasonable choice in certain settings. This narrative review is an attempt to critically summarize current evidence on regional anesthesia for laparoscopic surgery. Because most available data come from large, retrospective studies, large, rigorous, prospective clinical trials comparing regional vs. general anesthesia are needed to evaluate the true value of regional anesthesia in laparoscopic surgery.


Journal of Cardiothoracic and Vascular Anesthesia | 2005

Improved oxygenation during one-lung ventilation achieved with an embolectomy catheter acting as a selective lobar endobronchial blocker

George Vretzakis; Christos Dragoumanis; Basilios Papaziogas; Dimitrios Mikroulis


Turkısh Journal of Anesthesıa and Reanımatıon | 2018

Do Difficult Airway Techniques Predispose Obese Patients to Bronchospasm

Polyhronis Ieropoulos; Vassilios Tassoudis; Nick Ntafoulis; Ioanna Mimitou; George Vretzakis; George Tzovaras; Dimitrios Zacharoulis; Menelaos Karanikolas


Knee Surgery, Sports Traumatology, Arthroscopy | 2018

Superior perioperative analgesia with combined femoral–obturator–sciatic nerve block in comparison with posterior lumbar plexus and sciatic nerve block for ACL reconstructive surgery

Metaxia Bareka; Michael E. Hantes; Eleni Arnaoutoglou; George Vretzakis


SpringerPlus | 2016

Bronchospasm in obese patients undergoing elective laparoscopic surgery under general anesthesia

Vassilios Tassoudis; Hronis Ieropoulos; Menelaos Karanikolas; George Vretzakis; Aik Bouzia; Elias Mantoudis; Argyro Petsiti

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Menelaos Karanikolas

Washington University in St. Louis

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Aik Bouzia

University of Thessaly

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Christos Dragoumanis

Democritus University of Thrace

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Dimitrios Mikroulis

Democritus University of Thrace

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Basilios Papaziogas

Democritus University of Thrace

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Christos Iatrou

Democritus University of Thrace

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Constantinos Simopoulos

Democritus University of Thrace

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