The Effect of Pressure-Controlled Ventilation and Volume-Controlled Ventilation in Prone Position on Pulmonary Mechanics and Inflammatory Markers.

The aim of this present study is to compare the effect of pressure-controlled ventilation and volume-controlled ventilation on pulmonary mechanics and inflammatory markers in prone position. The study included 41 patients undergoing to vertebrae surgery. The patients were randomized into two groups: Group 1 received volume-controlled ventilation, while group 2 received pressure-controlled ventilation. The demographic data, pulmonary mechanics, the inflammatory marker levels just after the induction of anesthetics, at the 6th and 12th hours, and gas analysis from arterial blood samples taken at the beginning and the 30th minute were recorded. The inflammatory marker levels increased in both groups, without any significant difference among groups. Peak inspiratory pressure level was higher in the volume-controlled ventilation group. This study revealed that there is no difference regarding inflammatory marker levels between volume- and pressure-controlled ventilation.

Comparison of Transcutaneous Electrical Nerve Stimulation and Paravertebral Block for Postthoracotomy Pain Relief.

BACKGROUND: Inadequate relief of postthoracotomy pain is a major reason of increased occurrence of postoperative complications. We aimed to investigate and compare the effects of transcutaneous electrical nerve stimulation (TENS) and paravertebral block (PVB) to relieve pain after thoracotomy procedures. MATERIALS AND METHODS: We studied 40 patients who underwent thoracotomy. Patients were randomly allocated to receive either PVB (group P, n = 20) or TENS (group T, n = 20) for postoperative pain. The electrodes of TENS were placed 2 cm under and 2 cm over the thoracotomy cut on both posterior and anterior sides. The surgeon inserted paravertebral catheters using direct vision at the end of the surgery. A patient-controlled analgesia (PCA) device was connected to all patients. Visual analog scales, patient demand, and consumption of tramadol were evaluated postoperatively. RESULTS: Mean visual analog scale (VAS) values were significantly lower in group P for all time points. The patients in group P needed lower amounts of opioid (tramadol) and the difference was statistically significant (258.4 ± 13.52 mg vs. 314.4 ± 8.65 mg, p = 0.005). In addition, the number of demand attempts recorded from the PCA device was significantly lower in group P (14.95 ± 13.64 vs. 26.7 ± 17.34, respectively and p < 0.001). CONCLUSION: TENS has beneficial effects for pain relief after thoracotomy, without any side effects; however, it cannot provide sufficient pain relief when compared with PVB.

Impact of a lung-protective ventilatory strategy on systemic and pulmonary inflammatory responses during laparoscopic surgery: is it really helpful?

Laparoscopic surgery is performed by carbon dioxide (CO2) insufflation, but this may induce stress responses. The aim of this study is to compare the level of inflammatory mediators in patients receiving low tidal volume (VT) versus traditional VT during gynecological laparoscopic surgery. Forty American Society of Anesthesiologists (ASA) physical status 1 and 2 subjects older than 18 years old undergoing laparoscopic gynecological surgery were included. Systemic inflammatory response was assessed with serum IL-6, TNF-alpha, IL-8, and IL-1ß in patients receiving intraoperative low VT and traditional VT during laparoscopic surgery [within the first 5 min after endotracheal intubation (T1), 60 min after the initiation of mechanical ventilation (T2), and in the postanesthesia care unit 30 min after tracheal extubation (T3)]. Additionally, inflammatory response was assessed with bronchoalveolar lavage (BAL) at T1 and T3 periods. An increase in the serum levels of IL-6, TNF-alpha, IL-8, and IL-1ß was observed in both groups during the time periods of T1, T2, and T3. No significant differences were found in the serum and BAL levels of inflammatory mediators during time periods between groups. The results of the present study suggested that the lung-protective ventilation and traditional strategies are not different in terms of lung injury and inflammatory response during conventional laparoscopic gynecological surgery.

Effect of transversus abdominis plane block on cost of laparoscopic cholecystectomy anesthesia.

BACKGROUND: Use of transversus abdominis plane (TAP) block for postoperative analgesia is continuously increasing. However, few studies have investigated intraoperative effects of TAP block. We aimed to study the effects of TAP block in terms of cost-effectiveness and consumption of inhalation agents. MATERIAL AND METHODS: Forty patients undergoing laparoscopic cholecystectomy were enrolled in this study. Patients were randomly divided into 2 groups: Group 1 (n=20) patients received TAP block and Group 2 (n=20) patients did not receive TAP block. Standard anesthesia induction was used in all patients. For the maintenance of anesthesia, fractional inspired oxygen (FIO2) of 50% in air with desflurane was used with a fresh gas flow of 4 L/min. All patients were monitored with electrocardiography and for peripheral oxygen saturation (SpO2), end-tidal carbon dioxide (ET), heart rate (HR), noninvasive mean blood pressure (MBP), and bispectral index (BIS). Bilateral TAP blocks were performed under ultrasound guidance to Group 1 patients. The BIS value was maintained at between 40 and 50 during the surgery. The Dion formula was used to calculate consumption of desflurane for each patient. RESULTS: There was no difference between the groups with respect to demographic characteristics of the patients. Duration of anesthesia, surgery time, and dosage of fentanyl were similar in the 2 groups. However, the cost and consumption of desflurane was significantly lower in Group 1. CONCLUSIONS: Total anesthesia consumption was lower and the cost-effectiveness of anesthesia was better in TAP block patients with general anesthesia than in non-TAP block patients undergoing laparoscopic cholecystectomy.

Evaluation of low tidal volume with positive end-expiratory pressure application effects on arterial blood gases during laparoscopic surgery.

BACKGROUND: Pneumoperitoneum (PNP) and patient positions required for laparoscopy can induce pathophysiological changes that complicate anesthetic management during laparoscopic procedures. This study investigated whether low tidal volume and positive end-expiratory pressure (PEEP) application can improve ventilatory and oxygenation parameters during laparoscopic surgery. METHODS: A total of 60 patients undergoing laparoscopic surgery were randomized to either the conventional group (n = 30, tidal volume = 10 mL/kg, rate = 12/minute, PEEP = 0 cm H(2)O) or the low tidal group with PEEP group (n = 30, tidal volume = 6 mL/kg, rate = 18/minute, PEEP = 5 cm H(2)O) at maintenance of anesthesia. Hemodynamic parameters, peak plateau pressure (Pplat) and arterial blood gases results were recorded before and after PNP. RESULTS: There was a significant increase in the partial pressure of arterial carbon dioxide (PaCO(2)) values after PNP in the conventional group in the reverse Trendelenburg (41.28 mmHg) and Trendelenburg positions (44.80 mmHg;p = 0.001), but there was no difference in the low tidal group at any of the positions (36.46 and 38.56, respectively). We saw that PaO(2) values recorded before PNP were significantly higher than the values recorded 1 hour after PNP in the two groups at all positions. No significant difference was seen in peak inspiratory pressure (Ppeak) at the reverse Trendelenburg position before and after PNP between the groups, but there was a significant increase at the Trendelenburg position in both groups (conventional; 21.67 cm H(2)O, p = 0.041, low tidal; 23.67 cm H(2)O, p = 0.004). However, Pplat values did not change before and after PNP in the two groups at all positions. CONCLUSION: The application of low tidal volume + PEEP + high respiratory rate during laparoscopic surgeries may be considered to improve good results of arterial blood gases.

Exploring for the safer ventilation method in laparoscopic urologic patients? Conventional or low tidal?

BACKGROUND: To study the effects of low tidal volume with positive end-expiratory pressure (PEEP) on arterial blood gases of patients undergoing laparoscopic urologic surgeries. SUBJECTS AND METHODS: Eighty-six laparoscopic urologic patients were enrolled in this study. Patients were randomized into two groups according to the ventilatory settings. In the conventional group (Group C) (n=43), the tidal volume was 10 mL/kg, and the PEEP was set at 0 cm of H2O. In the low tidal volume with PEEP group (Group LP), the tidal volume was 6 mL/kg, with PEEP of 5 cm of H2O. In both groups total minute volume was 6 L/kg. Peak and plateau airway pressure (PPEAK and PPLAT, respectively) and arterial blood gases were recorded before pneumoperitoneum (PNP) (T1) and the first and third hour (T3) after PNP induction and also after extubation in the intensive care unit. Additionally, heart rate, mean arterial pressure, and peripheral O2 saturation of hemoglobin were recorded. RESULTS: Heart rate, PPEAK, and PPLAT values were similar in both groups. Partial arterial O2 pressure values measured postoperatively were significantly higher in Group LP, whereas those measured before PNP induction were similar (P=.014 and P=.056, respectively). Compared with the baseline, partial arterial CO2 pressure values measured at T1 and at T3 after PNP induction were significantly higher in Group C than in Group LP (P<.001). The pH values of Group C at T1 and at T3 postoperatively were significantly lower than the values of Group LP (P<.001). Extubation times were significantly lower in Group LP. CONCLUSIONS: The results of the present study suggest that low tidal volume with PEEP application may be a good alternative for preventing high CO2 levels and yielding better oxygenation and lower extubation times in patients undergoing prolonged laparoscopic urology.

Comparison of the effects of desflurane and propofol anesthesia on the inflammatory response and s100ß protein during coronary artery bypass grafting.

Cardiopulmonary bypass (CPB) contributes to the secretion of anti-inflammatory cytokines that mediate the inflammatory response observed during open heart surgery. In addition to many factors, type of anesthesia management affects immune response and central nervous system in cardiac surgery. The aim of this study was to assess the effect of propofol versus desflurane anesthesia on systemic immune modulation and central nervous system on patients undergoing coronary artery bypass grafting. Forty patients undergoing elective coronary artery bypass graft surgery with CPB were included in this prospective randomized study. Patients were allocated to receive propofol (n = 20) or desflurane (n = 20) for maintenance of anesthesia. The blood samples for IL-6, IL-8, TNF-α, and S100ß were drawn just prior to the operation before the induction of anesthesia, second before cardiopulmonary bypass, third after CPB, fourth 4 h postoperatively at the ICU. Major finding in our study is that S100ß levels were lower in propofol group when compared to desflurane anesthesia. And also immune reaction was less in patients exposed to desflurane anesthesia when compared to propofol anesthesia as indicated by lower plasma concentrations of IL-8 and IL-6. Propofol is more preferable in terms of S100ß for anesthetic management for CABG.

Advantages of autologous blood transfusion in off-pump coronary artery bypass.

BACKGROUND: In this randomized controlled study, we investigated the effects of autologous Hemobag blood transfusion (AHBT) and allogenic blood transfusion (ABT) in off-pump coronary artery bypass (OPCAB) surgery. METHODS: Sixty patients who underwent surgery between February 2008 and August 2008 were randomized into 2 groups. The AHBT group (n = 30) consisted of patients who received autologous Hemobag blood transfusion, and the ABT group (n = 30) consisted of patients who received allogenic blood transfusion. All patients underwent OPCAB via sternotomy. The time to extubation, chest tube drainage volume, postoperative white blood cell counts, amount of blood transfusion, sedimentation rate, C-reactive protein concentration, postoperative temperature, and the presence of atelectasis were recorded in the intensive care unit. RESULTS: Intraoperative bleeding and fluid resuscitation were similar in the 2 groups (P > .05); however, there were significant decreases in postoperative blood loss, extubation period, postoperative white cell counts, sedimentation rate, incidence of atelectasis, C-reactive protein, and fever in the AHBT group compared with the ABT group (P < .05). The rate of atrial fibrillation in the AHBT group tended to be lower than in the ABT group. CONCLUSION: Autologous blood transfusion in OPCAB may be beneficial in certain cardiac surgery patients; however, these beneficial effects require further study to be proved.

Comparison of continuous and intermittent transcutaneous electrical nerve stimulation in postoperative pain management after coronary artery bypass grafting: a randomized, placebo-controlled prospective study.

OBJECTIVE: We compared the effectiveness of continuous transcutaneous electrical nerve stimulation (TENS) and intermittent TENS in the management of pain after coronary artery bypass grafting (CABG). METHODS: We randomized 100 patients who had undergone median sternotomy for CABG into 4 groups with 25 patients each: (1) continuous TENS (CTENS) and pharmacologic analgesia, (2) intermittent TENS (ITENS) and pharmacologic analgesia, (3) placebo TENS (PTENS) and pharmacologic analgesia, and (4) pharmacologic analgesia alone (control). We studied these groups with regard to the relief of postoperative pain during the first 24 hours. For each patient we recorded the following: demographic characteristics; vital signs; intensity of pain with a visual analogue scale (VAS) before treatment (VAS(0)), at the 12th hour (VAS(12)), and at the 24th hour (VAS(24)); and analgesic intake. RESULTS: The groups were comparable with respect to age, sex, and body mass index at baseline. Mean VAS scores decreased within each group; however, the mean VAS(12) and VAS(24) scores decreased significantly in the CTENS and ITENS groups, compared with PTENS and control groups (P < .05). We found no significant difference between the CTENS and ITENS groups with respect to decreasing VAS(12) and VAS(24) scores (P > .05). Narcotic intake was significantly less in the CTENS and ITENS groups than in the control and PTENS groups (P < .01). Furthermore, narcotic requirements were significantly lower in the CTENS group than in the ITENS group (P < .01). CONCLUSIONS: CTENS and ITENS after median sternotomy for CABG decreased pain and reduced narcotic requirements more than in the PTENS and control treatments during first postoperative 24 hours. Neither CTENS nor ITENS is superior to the other in decreasing pain; however, CTENS leads to a greater reduction in the narcotic requirement than ITENS.

Gastrointestinal ischemia related mortality in patients undergoing off- or on-pump coronary artery bypass grafting.

OBJECTIVE: Gastrointestinal ischemia (GII) after heart surgery is a rare but devastating condition. The aim of this study was to compare the occurrence of GII after coronary artery bypass grafting (CABG) performed off-pump (OPCAB) vs on-pump (ONCAB). METHODS: We retrospectively evaluated 2625 adult patients who underwent isolated coronary artery surgery during a 6-year period. The OPCAB group included 658 patients and the ONCAB group 1967 patients. Patients were evaluated, and GII, morbidity, and mortality in the 2 groups were compared. RESULTS: GII developed in 0.4% (7 of 1967) patients in the ONCAB group and in 0.2% (1 of 658) patients in the OPCAB group (P = .28). Mortality rates due to GII were 0.2% (4 of 1967) in the ONCAB group, and no deaths occurred in the OPCAB group (P < .04). Postoperative atrial fibrillation incidence with GII was 100% (7 of 7) in ONCAB group and 0% (0 of 1) in the OPCAB group (P < .01). CONCLUSIONS: Compared to ONCAB, the OPCAB procedure has lower GII related mortality rates, which is an important cause of morbidity and mortality in the postoperative period of CABG surgery.

Does dexmedetomidine reduce secondary damage after spinal cord injury? An experimental study.

The aim of this experimental study was to investigate the possible protective effect of dexmedetomidine (DEX) on traumatic spinal cord injury (SCI). Twenty-two New Zealand rabbits were divided into three groups: sham (no drug or operation, n = 6), Control [SCI + single dose of 1 mL saline intraperitoneally (i.p), after trauma; n = 8] and DEX (SCI + 1 microg/kg dexmedetomidine in 1 mL, i.p, after trauma, n = 8). Laminectomy was performed at T10 and balloon angioplasty catheter was applied extradurally. Four and 24 h after surgery, rabbits were evaluated by an independent observer according to the Tarlov scoring system. Blood, cerebrospinal fluid (CSF), tissue samples from spinal cord were taken for biochemical and histopathological evaluations. After 4 h of SCI, all animals in control or DEX treated groups became paraparesic. On the other hand, 24 h after SCI, partial improvements were observed in both control and DEX treated groups. Traumatic SCI leads to increase in the lipid peroxidation and decreases enzymatic or nonenzymatic endogenous antioxidative defense systems. Again, SCI leads to apoptosis in spinal cord. DEX treatment slightly prevented lipid peroxidation and augmented endogenous antioxidative defense systems in CSF or spinal cord tissue, but failed to prevent apoptosis or neurodeficit after traumatic SCI. Therefore, it could be suggested that treatment with dexmedetomidine does not produce beneficial results in SCI.

The neuroprotective effect of dexmedetomidine in the hippocampus of rabbits after subarachnoid hemorrhage.

BACKGROUND: Subarachnoid hemorrhage is a serious condition, often accompanied by cerebral vasospasm, which may lead to brain ischemia and neurologic deterioration. We evaluated if dexmedetomidine has neuroprotective effects in the hippocampus of vasospastic SAH rabbits or not. MATERIALS AND METHODS: Eighteen New Zealand rabbits were taken. An experimental SAH model was formed by injecting 0.9 mL of autologous arterial blood per 1 kg of body weight to the cisterna magna of 12 rabbits. Craniotomy was performed in the control group (n = 6) except performing experimental SAH. Rabbits in the SAH-alone (n = 6) group were infused with 5 mL.kg(-1).h(-1) 0.9% sodium chloride, and rabbits (n = 6) in the SAH-dexmedetomidine group were infused with 5 microg.kg(-1).h(-1) dexmedetomidine for 2 hours, 48 hours after SAH was established. Rabbits of all groups were sacrificed via penthotal 24 hours after dexmedetomidine administration. Brains were removed immediately, and hippocampal tissues were blocked from the right hemisphere for histopathologic study. In addition to this, hippocampal tissues of left hemispheres were dissected for biochemical analyses to evaluate MDA levels, activity of XO, and SOD. RESULTS: The histopathologic study showed that dexmedetomidine may have a neuroprotective effect in SAH-induced hippocampal injuries. The biochemical parameters support the neuroprotective effect of dexmedetomidine (P < .05). CONCLUSION: Our study showed that dexmedetomidine may have a neuroprotective effect in the hippocampus of vasospastic SAH rabbits.