Ventilation In Thoracic Surgery Research Articles

Application of High Frequency Ventilation in Thoracic Surgery

Application of High Frequency Ventilation in Thoracic Surgery

The Effect of Patients’ Position on Arterial Oxygenation During One-Lung and Two-Lung Ventilation in Thoracic Surgery: Smoker vs. Nonsmoker Patients (A Pilot Study)

Background: One-lung ventilation (OLV) is often required to facilitate surgical exposure. Hypoxemia is a common disorder during thoracic surgery. Objectives: We studied whether changing from the supine to the lateral position during OLV and two-lung ventilation (TLV) in thoracic surgery would affect positions on arterial oxygen pressure (PaO2) in two groups of smokers and nonsmokers. Methods: This single-blinded prospective observational pilot study was conducted on patients who underwent thoracotomy under general anesthesia. The effect of lateral and supine PaO2 was investigated in 15 patients with a history of smoking (≥ 40 packs/year) and 15 patients without. The data were analyzed via descriptive and inferential statistics in SPSS v. 19. Results: Arterial oxygen pressure did not significantly differ between the two groups in the supine TLV (P = 0.98), supine OLV (P = 0.16), lateral TLV (P = 0.06), and lateral OLV (P = 0.31). However, the PaO2 level was higher in smokers than in nonsmokers (except during supine TLV). Changing the position from supine to lateral caused a relative decrease in PaO2 (except during TLV in smokers) during TLV and OLV. This reduction in PaO2 levels was less in smokers (72.12) than in nonsmokers (95.28). Oxygen saturation (SpO2) levels were the same in all positions regardless of whether they were a smoker or nonsmoker. Conclusions: Changing the position from supine to lateral had no significant effects on PaO2 and SpO2 levels in smoker and nonsmoker patients during OLV and TLV in thoracic surgery.

Research and development of the sOLVe Tube™ dual lumen endobronchial tube: from concept to construct.

Dual lumen endobronchial tubes (DLTs) are frequently used for lung isolation and one lung ventilation in thoracic surgery and other specialized clinical scenarios. Modern DLTs are large and rigid, and account for half of all tracheobronchial injuries. Their 70 year old design has numerous flaws which limit their safety and clinical utility. Our research team set out to design a new and improved DLT to mitigate these shortcomings, and then test the proposed device to ensure proper function. Using published airway anatomy data and computed tomography imaging from 195 thoracic surgery patients, we designed a new DLT with a single size/configuration that would fit into adult surgery patients. This single "Universal design" was intended to replace both left and right sided 35Fr-41Fr DLTs (8 total products), while remaining small in diameter (35Fr). Other design goals included: 1) making intubation easier and safer, 2) allowing full sized therapeutic bronchoscopes to fit into this tube, 3) making the DLT more resistant to dislodgement. After design process completion the proposed dimensions were tested against 195 patients' left and right mainstem bronchi for radiographic fit. Once production prototypes were manufactured, they were tested in large adult Yorkshire pigs and fresh human cadavers for anatomic fit and performance. The proposed design passed the radiographic fit test in all 195 patients for both left and right mainstem endobronchial placement. Intubation was successful and deemed atraumatic in all pigs and cadavers, and the device appropriately fit in both the right and left mainstem bronchi. Lung isolation was successfully achieved and the device proved resistant to axial force dislodgement. We propose a new design for a novel DLT meant to replace 8 currently supplied adult configurations with a single, one size/configuration fits all product that allows for large bore bronchoscopy and resists axial force dislodgement.

Optimization of protective lung ventilation in thoracic surgery

Background: Today protective ventilation is the predominant ventilation methodology. It includes the use of low tidal volume, inspiratory pressure limitation, and the application of positive end-expiratory pressure. However, several retrospective studies have shown that tidal volume, inspiratory pressure, and Positive End-Expiratory Pressure (PEEP) are not associated with patients’ treatment outcomes, but could be associated only when they influence driving pressure.Objective: Optimization of the strategy of protective one-lung ventilation under the control of driving pressure, to reduce early postoperative respiratory complications in patients operated for lung cancer.Material and methods: A prospective controlled study was conducted on 110 patients undergoing extended anatomical lung resections with subsequent comparison of clinical results depending on the level of driving pressure during one-lung ventilation. Postoperative pulmonary complications based on the Melbourne scale that appeared within 3 days after surgery became the endpoint.Results: A correlation was established between the level of driving pressure and the level of PaO2 in the intraoperative period – high inverse (r = – 0.901). The greatest value in the development of postoperative respiratory failure is driving pressure, exceeding 15 cm of water (Odds ratio = 18.25). In the first 3 days, postoperative pulmonary complications, determined by the Melbourne group scale, occurred in 9 (8.2%) patients in whom the driving pressure exceeded 15 cm of water, and in 3 patients (2.7%) with a driving pressure level less than 15 cm of water (p = 0.016).Conclusion: Driving pressure excess with values of more than 15 cm of water significantly increases the incidence of postoperative pulmonary complications. Fixed PEEP will be inappropriate both high and low, and individualized PEEP titrated by CStat may reduce driving pressure and become the next step in protective one-lung ventilation.

Anesthesiology of the spontaneous ventilation in thoracic surgery: a narrative review

Anesthesiology of the spontaneous ventilation in thoracic surgery: a narrative review

Comparison of left double lumen tube and y-shaped and double-ended bronchial blocker for one lung ventilation in thoracic surgery\u2014a randomised controlled clinical trial

BackgroundDouble lumen tube (DLT) intubation is the most commonly used technique for one lung ventilation. Bronchial blockers (BB) are an alternative, especially for difficult airways. The EZ-bronchial blocker (EZB) is an innovative y-shaped and double-ended device of the BB family.MethodsA randomised, controlled trial was conducted in 80 patients undergoing elective thoracic surgery using DLT or EZB for one lung ventilation (German Clinical Trial Register DRKS00014816). The objective of the study was to compare the clinical performance of EZB with DLT. Primary endpoint was total time to obtain successful one lung ventilation. Secondary endpoints were time subsections, quality of lung collapse, difficulty of intubation, any complications during the procedure, incidence of objective trauma of the oropharynx and supraglottic space and intubation-related subjective symptoms.Results74 patients were included, DLT group (n = 38), EZB group (n = 36). Median total time to obtain one lung ventilation [IQR] in the DLT group was 234 s [207 to 294] versus 298 s [243 to 369] in the EZB group (P = 0.007). Median total time was relevantly influenced by different preparation times. Quality of lung collapse was equal in both groups, DLT group 89.5% were excellent vs. 83.3% in the EZB group (P = 0.444). Inadequate lung collapse in five patients of the EZB group resulted in unsuccessful repositioning attempts and secondary DLT placement. Endoscopic examinations revealed significantly more carina trauma (P = 0.047) and subglottic haemorrhage (P = 0.047) in the DLT group. Postoperative subjective symptoms (sore throat, hoarseness) were more common in the DLT group, as were speech problems.ConclusionsUsing EZB prima facie results in prolonged time to obtain one lung ventilation with equal quality of lung collapse for the thoracic surgeon. If preparation times are omitted in the analysis, the time difference is statistically and clinically not relevant. Our data showed only little evidence for reducing objective airway trauma as well as subjective complaints. In summary both procedures were comparable in terms of times and clinical applicability. Therefore decisions for DLT or EZB should depend more on individual experience, in-house equipment and the individual patient, than on any times that are neither clinically significant nor relevant.Trial registrationGerman Clinical Trial Register DRKS00014816, prospectively registered on 07.06.2018

The Effect of Fiberoptic Bronchoscopy-guided Technique for Placement of a Left-sided Double-lumen Tube on the Intubation Performance Compared with the Conventional Method Using a Macintosh Laryngoscope

Background: The accurate placement of the double-lumen endotracheal tube is imperative for effective one-lung ventilation in thoracic surgery. Malpositioning and repositioning of a misplaced tube may cause excessive trauma. Objective: We hypothesized that the fiberoptic bronchoscope-guided method for double-lumen endotracheal tube placement would reduce the incidence of malpositioning as compared to the conventional method using the Macintosh laryngoscope. Methods: Fifty patients scheduled to undergo elective thoracic surgery were recruited and randomly assigned to the fiberoptic bronchoscope-guided [n=25; Group F] and conventional [n=25; Group C] method groups, according to the method of double-lumen endotracheal tube placement. The primary outcome was the incidence of double-lumen endotracheal tube malpositioning observed under the fiberoptic bronchoscope after initial placement. Secondary outcomes included the times for placement, confirmation, and total procedure of double-lumen endotracheal tube intubation. Results: The incidence of malpositioning after initial double-lumen endotracheal tube placement was significantly lower in Group F than in Group C (20.0% vs 68.0%). In addition, the time for placement was significantly higher in Group F than in Group C, and that for confirmation was significantly lower in Group F than in Group C. Conclusion: The fiberoptic bronchoscope-guided method for double-lumen endotracheal tube placement can reduce the incidence of malpositioning after initial placement and expedite the intubation process with a double-lumen endotracheal tube in thoracic surgery.

Effect of Dexmedetomidine Combined with Inhalation of Isoflurane on Oxygenation Following One-Lung Ventilation in Thoracic Surgery.

BackgroundOne-lung ventilation (OLV) is commonly used during thoracic surgery. At this time, hypoxemia is considered one of the remarkable consequences of the anesthesia management. Hypoxic pulmonary vasoconstriction (HPV) is the defense mechanism against hypoxia.ObjectivesThe aim of the present study was to investigate the effect of infusion of dexmedetomidine on improving the oxygenation during OLV among the adult patients undergoing thoracic surgery.MethodsA total of 42 patients undergoing OLV by general anesthesia with isoflurane inhalation were randomly assigned into two groups: IV infusion of dexmedetomidine at 0.3 microgram/kg/h (DISO) and IV infusion of normal saline (NISO). Three Arterial Blood Gas (ABG) samples were obtained throughout the surgery. Hemodynamic parameters, PaO2, PaCO2, and complications at recovery phase were recorded. The collected information was analyzed using SPSS software version 22.ResultsIn the dexmedetomidine group, the mean hemodynamic parameters had a significant reduction at 30 and 60 minutes following OLV. Administration of dexmedetomidine resulted in a significant increase in the PaCO2 and a reduction in the PaO2 when changing from two-lung ventilation to OLV, where PaO2 reached its maximum value within 10 minutes after OLV in the DISO group, and it began to gradually increase to the end of operation. The duration of the recovery phase, also complications at the recovery phase decreased significantly in DISO group.ConclusionsThe results of the study showed that, dexmedetomidine may improve arterial oxygenation during OLV in adult patients undergoing thoracic surgery, and can be a suitable anesthetic agent for thoracic surgery.

Effect of anesthesia depth on stress response during single-lung ventilation in thoracic surgery

Objective To study the effects of different anesthesia depths on stress response during single-lung ventilation in patients with thoracoscopic lobectomy. Methods Sixty patients selected for elective thoracoscopic lobectomy in the Second Hospital of Shanxi Medical University from September 2018 to May 2019 were randomly divided into three groups according to the digital random table method, with 20 patients in each group. Group A maintained deep anesthesia with the bispectral index (BIS) 36-45, group B maintained moderate anesthesia with BIS 46-55, and group C did not undergo BIS monitoring. The changes of heart rate, mean arterial pressure (MAP), stress indexes cortisol and blood glucose before anesthesia induction (T0), immediately after one-lung ventilation (T1), 60 min after one-lung ventilation (T2) and immediately after skin suture (T3) in the three groups were compared. Results The concentration of blood glucose in group A at T1, T2 and T3 was (5.28±0.49) mmol/L, (5.34±0.49) mmol/L and (5.40±0.47) mmol/L, and the cortisol was (142.75±31.45) ng/ml, (181.36±19.62) ng/ml and (153.81±33.92) ng/ml; the blood glucose in group B was (5.63±0.35) mmol/L, (6.06±0.19) mmol/L and (5.79±0.44) mmol/L, and the cortisol was (168.45±31.16) ng/ml, (171.09±25.28) ng/ml and (159.39±18.77) ng/ml; the blood glucose in group C was (6.35±0.56) mmol/L, (7.04±0.26) mmol/L and (6.17±0.54) mmol/L, and the cortisol was (191.13±46.00) ng/ml, (283.25±30.07) ng/ml and (183.01±19.71) ng/ml, respectively. The blood glucose and cortisol levels in group C at T1, T2 and T3 were higher than those in group A and group B (all P < 0.05). The MAP in group A at T1, T2 and T3 were (69±5) mmHg (1 mmHg= 0.133 kPa), (67±6) mmHg and (75±7) mmHg, respectively, and group B was (80±8) mmHg, (79±4) mmHg and (84±9) mmHg, the differences between the two groups were statistically significant (all P < 0.05). There was significant difference in cortisol between group A and group B at T1 (P < 0.05). The heart rate and MAP at T1, T2 and T3 in group A and group C were significantly different from those at T0 (all P < 0.05). The heart rate and MAP at T1 and T2 in groups B were significantly different from those at T0 (all P < 0.05). Conclusion BIS anesthesia depth monitoring should be performed during single-lung ventilation in thoracic surgery, and BIS should be maintained at 46-55, which can not only inhibit the stress response but also have a slight effect on hemodynamics. Key words: Surgical procedures, operative; Monitoriry, intraoperative; Stress; Depth of anesthesia; Bispectral index monitoring

Driving Pressure during Thoracic Surgery: A Randomized Clinical Trial.

Driving pressure (plateau minus end-expiratory airway pressure) is a target in patients with acute respiratory distress syndrome, and is proposed as a target during general anesthesia for patients with normal lungs. It has not been reported for thoracic anesthesia where isolated, inflated lungs may be especially at risk. In a double-blinded, randomized trial (292 patients), minimized driving pressure compared with standard protective ventilation was associated with less postoperative pneumonia or acute respiratory distress syndrome. Recently, several retrospective studies have suggested that pulmonary complication is related with driving pressure more than any other ventilatory parameter. Thus, the authors compared driving pressure-guided ventilation with conventional protective ventilation in thoracic surgery, where lung protection is of the utmost importance. The authors hypothesized that driving pressure-guided ventilation decreases postoperative pulmonary complications more than conventional protective ventilation. In this double-blind, randomized, controlled study, 292 patients scheduled for elective thoracic surgery were included in the analysis. The protective ventilation group (n = 147) received conventional protective ventilation during one-lung ventilation: tidal volume 6 ml/kg of ideal body weight, positive end-expiratory pressure (PEEP) 5 cm H2O, and recruitment maneuver. The driving pressure group (n = 145) received the same tidal volume and recruitment, but with individualized PEEP which produces the lowest driving pressure (plateau pressure-PEEP) during one-lung ventilation. The primary outcome was postoperative pulmonary complications based on the Melbourne Group Scale (at least 4) until postoperative day 3. Melbourne Group Scale of at least 4 occurred in 8 of 145 patients (5.5%) in the driving pressure group, as compared with 18 of 147 (12.2%) in the protective ventilation group (P = 0.047, odds ratio 0.42; 95% CI, 0.18 to 0.99). The number of patients who developed pneumonia or acute respiratory distress syndrome was less in the driving pressure group than in the protective ventilation group (10/145 [6.9%] vs. 22/147 [15.0%], P = 0.028, odds ratio 0.42; 95% CI, 0.19 to 0.92). Application of driving pressure-guided ventilation during one-lung ventilation was associated with a lower incidence of postoperative pulmonary complications compared with conventional protective ventilation in thoracic surgery.

Peep titration based on the open lung approach during one lung ventilation in thoracic surgery: a physiological study

BackgroundDuring thoracic surgery in lateral decubitus, one lung ventilation (OLV) may impair respiratory mechanics and gas exchange. We tested a strategy based on an open lung approach (OLA) consisting in lung recruitment immediately followed by a decremental positive-end expiratory pressure (PEEP) titration to the best respiratory system compliance (CRS) and separately quantified the elastic properties of the lung and the chest wall. Our hypothesis was that this approach would improve gas exchange. Further, we were interested in documenting the impact of the OLA on partitioned respiratory system mechanics.MethodsIn thirteen patients undergoing upper left lobectomy we studied lung and chest wall mechanics, transpulmonary pressure (PL), respiratory system and transpulmonary driving pressure (ΔPRS and ΔPL), gas exchange and hemodynamics at two time-points (a) during OLV at zero end-expiratory pressure (OLVpre-OLA) and (b) after the application of the open-lung strategy (OLVpost-OLA).ResultsThe external PEEP selected through the OLA was 6 ± 0.8 cmH2O. As compared to OLVpre-OLA, the PaO2/FiO2 ratio went from 205 ± 73 to 313 ± 86 (p = .05) and CL increased from 56 ± 18 ml/cmH2O to 71 ± 12 ml/cmH2O (p = .0013), without changes in CCW.Both ΔPRS and ΔPL decreased from 9.2 ± 0.4 cmH2O to 6.8 ± 0.6 cmH2O and from 8.1 ± 0.5 cmH2O to 5.7 ± 0.5 cmH2O, (p = .001 and p = .015 vs OLVpre-OLA), respectively. Hemodynamic parameters remained stable throughout the study period.ConclusionsIn our patients, the OLA strategy performed during OLV improved oxygenation and increased CL and had no clinically significant hemodynamic effects. Although our study was not specifically designed to study ΔPRS and ΔPL, we observed a parallel reduction of both after the OLA.Trial registrationTRN: ClinicalTrials.gov, NCT03435523, retrospectively registered, Feb 14 2018.

A novel technique for endobronchial blocker placement for one-lung ventilation in children under 2 years.

The present study aimed to report our clinical experience with intraluminal calculated distance for endobronchial blocker placement (ICEB) and to find out whether ICEB could reduce the number of hypoxemia episodes during blocker placement compared with extraluminal blocker placement for one-lung ventilation in children under the age of 2years. The medical records of all children under the age of 2years with a 5 French (F) or 4F WeiLi (WeiLi medical Inc, Guangzhou, China) endobronchial blocker for one-lung ventilation in thoracic surgery from July 2015 through July 2016 were retrospectively reviewed. After November 2015, one-lung ventilation was achieved using the ICEB technique, while before November 2015, extraluminal blocker placement was used. The success rate of blocker placement, quality of lung deflation, number of hypoxemia episodes, blocker dislodgement, and successful reposition after dislodgement were compared between the two groups. The incidence of hypoxemia episodes during blocker placement was lower in the ICEB group compared to the extraluminal placement group. Moreover, the success rate of blocker reposition during the operation was higher in the ICEB group than the extraluminal placement group. The success rate of endobronchial blocker placement was similar between the two groups. Intraluminal calculated distance for endobronchial blocker placement is a feasible method to achieve lung isolation and could reduce hypoxemia episodes during blocker placement in children under the age of 2years.

New evidence in one-lung ventilation

Mechanical ventilation in thoracic surgery has undergone significant changes in recent years due to the implementation of the protective ventilation. This review will analyze recent ventilatory strategies in one-lung ventilation. A MEDLINE research was performed using Mesh term One-Lung Ventilation including randomized clinical trials, metanalysis, reviews and systematic reviews published in the last 6 years. Search was performed on 21st March 2017. A total of 75 articles were initially found. After title and abstract review 14 articles were included. Protective ventilation is not simply synonymous of low tidal volume ventilation, but it also includes routine use of PEEP and alveolar recruitment maneuver. New techniques are still in discussion namely PEEP adjustment, ratio inspiration:expiration, ideal type of anesthesia during one-lung ventilation and hypercapnic ventilation.

Effect of propofol and isoflurane on gas exchange parameters following one-lung ventilation in thoracic surgery: a double-blinded randomized controlled clinical trial.

BackgroundThe use of anesthetic drugs with minimal inhibitory effects on the hypoxic pulmonary vasoconstriction (HPV) could have a decisive role in preventing the hypoxemia during one-lung ventilation (OLV).ObjectiveThe aim of this study was to compare the effects of propofol and isoflurane on the changes in gas exchange parameters following OLV in thoracic surgery.MethodsThis double-blinded randomized controlled clinical trial was conducted on patients who were candidates for elective right thoracotomy referred to the central operating room of Ghaem Hospital in Mashhad, Iran, during February 2016–2017. Patients with age range of 18 to 75 years, class I and II American Society of Anesthesiologists (ASA) and thoracotomy with OLV for pulmonary resection or cyst drainage were included. The patients were randomly allocated (1:1 ratio) into two groups of propofol (P, 50–100μg/kg/min) and isoflurane (I, 1 minimum alveolar concentration (MAC) 1.1%). Partial pressure of carbon dioxide (PaCO2), partial pressure of oxygen (PaO2), end-tidal carbon dioxide (ETCO2) and arterial oxygen saturation (SPO2) were recorded before and 15 minutes after OLV and compared between the two groups. The comparison of the mean gas exchange parameters before and 15 minutes after OLV was performed using Mann-Whitney test in SPSS version 19 software. P<0.05 was considered statistically significant.ResultsIn this study, 122 patients with mean age of 59.4±14.1 years (two groups of 61) were studied. Both groups were matched for age or gender. The two groups had no significant difference in the gas exchange parameters before the OLV. Only PaCO2 (p=0.001) and ETCO2 (p=0.001) were significantly higher in the propofol group after 15 minutes OLV than in the isoflurane group. However, PaO2 (p=0.67), O2Sat (p=0.333) and PaCO2-ETCO2 gradient (p=0.809) showed no significant difference between the two groups at this minute.ConclusionBased on the results of this study, the propofol or isoflurane selection seems to have no significant effect on the arterial oxygenation. On the other hand, isoflurane and propofol could be an appropriate anesthetic for thoracic surgery by normalizing the carbon dioxide gradient range during the OLV.Clinical Trial RegistrationThe study was also registered at the Iranian Registry of Clinical Trials (IRCT2015123013159N8).FundingThe study was financially supported by the Deputy of Research of Mashhad University of Medical Sciences (grant number: 940119).

Bronchial blocker positioning: learning curve and confidence in its use.

Despite being simple and safe to use and cheap, EZ blocker (EZB) remains underused probably because it requires particular skills in recognizing airway and in using fiber-bronchoscopy to check the exact position of their cuffs. Thus, we planned an education training program on the use of EZB for novices in anesthesia and evaluated the number of procedures required for the acquisition of the skills of this technique. The educational training program included three different phases as follows. The first phase included a lecture on the utility of one-lung ventilation in thoracic surgery, on the use of the fiber- bronchoscopy and on the characteristics of EZB. The second phase consisted in a practical teaching course performed on a manikin model to acquire the skills in EZB. The third phase was a clinical training where each participant performed a defined number in patients scheduled for thoracic surgery procedures. The acquisition of dexterity and satisfaction were then statistically valuated. The dexterity in placing EZB significantly increased after six attempts (P<0.1). Participants acquired skills in correcting position EZB after 15 attempts. Participants increased their level of confidence with EZB (score 5.7±1.3) and were highly satisfied with the training received (score 5.8±1.6). EZB is a valid strategy for obtaining one lung ventilation. Thus, it should be included in the armamentarium of all anesthetists interested in the field of thoracic surgery. Our teaching course seems to be a valuable method to instill easily and speedily in training novices in anesthesia the skills in placing EZB.

Comparison of Arndt-endobronchial blocker plus laryngeal mask airway with left-sided double-lumen endobronchial tube in one-lung ventilation in thoracic surgery in the morbidly obese.

This study aimed to evaluate the feasibility and performance of Arndt-endobronchial blocker (Arndt) combined with laryngeal mask airway (LMA) compared with left-sided double-lumen endobronchial tube (L-DLT) in morbidly obese patients in one-lung ventilation (OLV). In a prospective, randomized double-blind controlled clinical trial, 80 morbidly obese patients (ASA I-III, aged 20–70) undergoing general anesthesia for elective thoracic surgeries were randomly allocated into groups Arndt (n=40) and L-DLT (n=40). In group Arndt, a LMA™ Proseal was placed followed by an Arndt-endobronchial blocker. In group L-DLT, patients were intubated with a left-sided double-lumen endotracheal tube. Primary endpoints were the airway establishment, ease of insertion, oxygenation, lung collapse and surgical field exposure. Results showed similar ease of airway establishment and tube/device insertion between the two groups. Oxygen arterial pressure (PaO2) of patients in the Arndt group was significantly higher than L-DLT (154±46 vs 105±52 mmHg; P<0.05). Quality of lung collapse and surgical field exposure in the Arndt group was significantly better than L-DLT (effective rate 100 vs 90%; P<0.05). Duration of surgery and anesthesia were significantly shorter in the Arndt group (2.4±1.7 vs 3.1±1.8 and 2.8±1.9 vs 3.8±1.8 h, respectively; P<0.05). Incidence of hoarseness of voice and incidence and severity of throat pain at the post-anesthesia care unit and 12, 24, 48, and 72 h after surgery were significantly lower in the Arndt group (P<0.05). Findings suggested that Arndt-endobronchial blocker combined with LMA can serve as a promising alternative for morbidly obese patients in OLV in thoracic surgery.

Effects of Dexmedetomidine Infusion on Inflammatory Responses and Injury of Lung Tidal Volume Changes during One-Lung Ventilation in Thoracoscopic Surgery: A Randomized Controlled Trial

One-lung ventilation in thoracic surgery provokes profound systemic inflammatory responses and injury related to lung tidal volume changes. We hypothesized that the highly selective a2-adrenergic agonist dexmedetomidine attenuates these injurious responses. Sixty patients were randomly assigned to receive dexmedetomidine or saline during thoracoscopic surgery. There is a trend of less postoperative medical complication including that no patients in the dexmedetomidine group developed postoperative medical complications, whereas four patients in the saline group did (0% versus 13.3%, p = 0.1124). Plasma inflammatory and injurious biomarkers between the baseline and after resumption of two-lung ventilation were particularly notable. The plasma high-mobility group box 1 level decreased significantly from 51.7 (58.1) to 33.9 (45.0) ng.ml−1 (p < 0.05) in the dexmedetomidine group, which was not observed in the saline group. Plasma monocyte chemoattractant protein 1 [151.8 (115.1) to 235.2 (186.9) pg.ml−1, p < 0.05] and neutrophil elastase [350.8 (154.5) to 421.9 (106.1) ng.ml−1, p < 0.05] increased significantly only in the saline group. In addition, plasma interleukin-6 was higher in the saline group than in the dexmedetomidine group at postoperative day 1 [118.8 (68.8) versus 78.5 (58.8) pg.ml−1, p = 0.0271]. We conclude that dexmedetomidine attenuates one-lung ventilation-associated inflammatory and injurious responses by inhibiting alveolar neutrophil recruitment in thoracoscopic surgery.

Factors Influencing Regional Cerebral Oxygen Saturation during One-lung Ventilation in Thoracic Surgery.

Objective To identify factors influencing regional cerebral oxygen saturation (rScO2) during one-lung ventilation (OLV) in thoracic surgery. Methods Totally 33 patients with an ASA physical status of 1-3 scheduled for elective thoracic surgery with one-lung ventilation under general anesthesia were recruited. After anesthesia was induced with propofol,fentanyl/sufentanil,and rocuronium. All patients received balanced anesthesia using sevoflurane. During OLV,volume-controlled ventilation was used with a tidal volume of 6-7 ml/kg and an inspiration:expiration ratio of 1:1.5. The ventilator frequency was adjusted with a target end-tidal carbon dioxide partial pressure (PetCO2) between 35 mmHg and 45 mmHg. During the anesthesia,patients were maintained at a pulse oxygen saturation (SpO2) of>90%,systolic blood pressure (SBP) of>90 mmHg (or reducing no more than 30% of the basic values),heart rate (HR) of>50 beat/min,and hemoglobin concentration of>90 g/L. Changes of rScO2 were monitored with FORESIGHT probes by specialized researchers. Patients were classified into low rScO2 (L-rScO2) group (n=10) or high rScO2 (H-rScO2)group(n=23) according to whether the lowest intraoperative rScO2 was under 65% or 15% lower than the baseline values. We compared gender,age,body mass index (BMI),intraoperative hemoglobin level,and the values of peak airway pressure (Ppeak),SBP,PetCO2,and SpO2 when rScO2 dropped to the lowest level between these two groups. Results Statistically higher Ppeak and lower SBP were noted in the L-rScO2 group compared with H-rScO2 group (P=0.028,P=0.046). SpO2 was lower in the L-rScO2 group compared with H-rScO2 group,but the difference was not statistically significant (P=0.421). There was also no significant difference between the two groups according to age,BMI,SpO2,PetCO2,or hemoglobin level. Ppeak appeared to be a risk factor for rScO2 reduction during OLV,as shown by unconditioned Logistic regression analysis. Conclusion During OLV in thoracic surgery,Ppeak is a risk factor for rScO2 reduction.

Nueva evidencia en ventilación unipulmonar

Mechanical ventilation in thoracic surgery has undergone significant changes in recent years due to the implementation of the protective ventilation. This review will analyze recent ventilatory strategies in one-lung ventilation.A MEDLINE research was performed using Mesh term “One-Lung Ventilation” including randomized clinical trials, metanalysis, reviews and systematic reviews published in the last 6 years. Search was performed on 21st March 2017. A total of 75 articles were initially found. After title and abstract review 14 articles were included.Protective ventilation is not simply synonymous of low tidal volume ventilation, but it also includes routine use of PEEP and alveolar recruitment maneuver. New techniques are still in discussion namely PEEP adjustment, ratio inspiration:expiration, ideal type of anesthesia during one-lung ventilation and hypercapnic ventilation.

Comparison Between Pressure-Regulated Volume-Controlled and Volume-Controlled Ventilation on Oxygenation Parameters, Airway Pressures, and Immune Modulation During Thoracic Surgery

To compare 2 different ventilatory strategies: pressure-regulated volume-controlled (PRVC) versus volume-controlled ventilation during thoracotomy. Prospective randomized study. University hospital. The study comprised 70 adult patients undergoing thoracic surgery. Evaluation of oxygenation parameters, airway pressures, and immune modulation. The primary outcome was arterial oxygen tension/fraction of inspired oxygen (PaO2/FIO2) ratio, whereas secondary outcomes included arterial and central venous blood gases, deadspace volume/tidal volume ratio, peak inspiratory pressure, mean inspiratory pressure, and plateau inspiratory pressure obtained at the following 4 time points: 20 minutes after total lung ventilation (T0), 20 minutes after 1-lung ventilation (T1), 20 minutes after return to total lung ventilation (T2), and at the end of surgery (T3). Furthermore, alveolar and plasma levels of interleukin-8 and tumor necrosis factor-α and changes in alveolar albumin levels and cell numbers were measured at the same time points. Oxygenation parameters (PaO2/FIO2 and PaO2) were significantly better in the PRVC group (PaO2/FIO2 ratio at T1 was 176 v 146 in the PRVC and volume-controlled groups, respectively, with a p value of 0.004). Deadspace volume/tidal volume ratio and inspiratory airway pressures were significantly lower in the PRVC group. Furthermore, all inflammatory parameters (alveolar and plasma interleukins, alveolar albumin levels, and cell numbers) were significantly lower in the PRVC group. The PRVC mode during 1-lung ventilation in thoracic surgery caused a favorable effect on oxygenation parameters, respiratory mechanics, and immune modulation during thoracic surgery.