One-lung Ventilation Research Articles

Intraoperative Variables Enhance the Predictive Performance of Myocardial Injury in Patients with High Cardiovascular Risk After Thoracic Surgery When Added to Baseline Prediction Model.

Myocardial injury after non-cardiac surgery is closely related to major adverse cardiac and cerebrovascular event and is difficult to identify. This study aims to investigate how to predict the myocardial injury of thoracic surgery and whether intraoperative variables contribute to the prediction of myocardial injury. The prospective study included adult patients with high cardiovascular risk who underwent elective thoracic surgery from May 2022 to October 2022. Multivariate logistic regression was used to establish a model with baseline variables and a model with baseline and intraoperative variables. We compare the predictive performance of two models for postoperative myocardial injury. In general, 31.5% (94 of 298) occurred myocardial injury. Age ≥65 years old, obesity, smoking, preoperative hsTnT, and one-lung ventilation time were independent predictors of myocardial injury. Compared with baseline model, the intraoperative variables improved model fit, modestly improved the reclassification (continuous net reclassification improvement 0.409, 95% CI, 0.169 to 0.648, P<0.001, improved integrated discrimination 0.036, 95% CI, 0.011 to 0.062, P<0.01) of myocardial injury cases, and achieved higher net benefit in decision curve analysis. The risk stratification and anesthesia management of high-risk patients are essential. The addition of intraoperative variables to the baseline predictive model improved the performance of the overall model of myocardial injury and helped anesthesiologists screen out the patients at the greatest risk for myocardial injury and adjust anesthesia strategies.

One-Lung Ventilation and Postoperative Pulmonary Complications After Major Lung Resection Surgery. A Multicenter Randomized Controlled Trial

The effect of one-lung ventilation (OLV) strategy based on low tidal volume (TV), application of positive end-expiratory pressure (PEEP), and alveolar recruitment maneuvers (ARM) to reduce postoperative acute respiratory distress syndrome (ARDS) and pulmonary complications (PPCs) compared with higher TV without PEEP and ARM strategy in adult patients undergoing lobectomy or pneumonectomy has not been well established. Multicenter, randomized, single-blind, controlled trial. Sixteen Italian hospitals. A total of 880 patients undergoing elective major lung resection. Patients were randomized to receive lower tidal volume (LTV group: 4 mL/kg predicted body weight, PEEP of 5 cmH2O, and ARMs) or higher tidal volume (HTL group: 6 mL/kg predicted body weight, no PEEP, and no ARMs). After OLV, until extubation, both groups were ventilated using a tidal volume of 8 mL/kg and a PEEP value of 5 cmH2O. The primary outcome was the incidence of in-hospital ARDS. Secondary outcomes were the in-hospital rate of PPCs, major cardiovascular events, unplanned intensive care unit (ICU) admission, in-hospital mortality, ICU length of stay, and in-hospital length of stay. ARDS occurred in 3 of 438 patients (0.7%, 95% CI 0.1-2.0) and in 1 of 442 patients (0.2%, 95% CI 0-1.4) in the LTV and HTV group, respectively (Risk ratio: 3.03 95% CI 0.32-29, p=0.372). Pulmonary complications occurred in 125 of 438 patients (28.5%, 95% CI 24.5-32.9) and in 136 of 442 patients (30.8%, 95% CI 26.6-35.2) in the LTV and HTV group, respectively (risk ratio: 0.93, 95% CI 0.76-1.14, p=0.507). The incidence of major complications, in-hospital mortality, and unplanned ICU admission, ICU and in-hospital length of stay were comparable in both groups. In conclusion, among adult patients undergoing elective lung resection, an OLV with lower tidal volume, PEEP 5 cmH2O, and ARMs and a higher tidal volume strategy resulted in low ARDS incidence and comparable postoperative complications, in-hospital length of stay, and mortality.

Impact of Lower Tidal Volumes During One-Lung Ventilation: A 2022 Update of the Meta-analysis of Randomized Controlled Trials

To clarify the influence of lower tidal volume (4-7 mL/kg) compared with higher tidal volume (8-15 mL/kg) during one-lung ventilation (OLV) on gas exchange and postoperative clinical outcome. Meta-analysis of randomized trials. Thoracic surgery. Patients receiving OLV. Lower tidal volume during OLV. Primary outcome was PaO2-to-the oxygen fraction (PaO2/FIO2) ratio at the end of the surgery, after the reinstitution of two-lung ventilation. Secondary endpoints included perioperative changes in PaO2/FIO2 ratio and carbon dioxide (PaCO2) tension, airway pressure, the incidence of postoperative pulmonary complications, arrhythmia, and length of hospital stay. Seventeen randomized controlled trials (1,463 patients) were selected. Overall analysis showed that the use of low tidal volume during OLV was associated with a significantly higher PaO2/FIO2 ratio 15 minutes after the start of OLV and at the end of surgery (mean difference 33.7 mmHg [p=0.02] and mean difference 18.59 mmHg [p < 0.001], respectively). The low tidal volume also was associated with higher PaCO2 values 15 minutes and 60 minutes after the start of OLV and with lower airway pressure, which was maintained during two-lung ventilation after surgery. Moreover, the application of lower tidal volume was associated with fewer postoperative pulmonary complications (odds ratio 0.50; p < 0.001) and arrhythmias (odds ratio 0.58; p=0.009), with no difference in length of hospital stay. The use of lower tidal volume, a component of protective OLV, increases the PaO2/FIO2 ratio, reduces the incidence of postoperative pulmonary complications, and should be considered strongly in daily practice.

A Chest Tube Inadvertently Inserted into Tracheal Lumen

The accompanying images demonstrate the presence of the distal end of a chest tube in the tracheal lumen just above the carina. These images are from a patient who developed coughing and massive air leak after chest tube placement. Inadvertent tracheal injury during chest tube placement should heighten suspicion for concomitant lung injury.1 Massive air leak in tracheobronchial disruption leads to low tidal volumes, lung atelectasis, and increased work of breathing. Consequently, respiratory distress may ensue, necessitating urgent intubation. In hemodynamically stable patients, bronchoscopy-guided endotracheal intubation is encouraged. This allows for airway examination, confirmation of tracheal injury site, and determination of the best strategy for achieving lung isolation to facilitate surgical repair.Lung isolation allows for mechanical ventilation of the uninjured lung and helps avoid pressurization of surgical repair site, minimizing risk of further disruption. In patients with bronchial injury, advancing the single-lumen endotracheal tube or placing a double-lumen endotracheal tube into the contralateral uninjured bronchus are possible options. In patients with carinal injury, creation of a large tracheostomy through which small endotracheal tubes are advanced into bilateral main stem bronchi allows delivery of mechanical ventilation while minimizing pressurization of the repaired carina.2 Tenuous cardiopulmonary status before induction of anesthesia or inability to maintain adequate oxygenation during one-lung ventilation may necessitate institution of peripheral extracorporeal membrane oxygenation to facilitate surgical repair. Importantly, removal of the chest tube leads to loss of its tamponade effect on lacerated pulmonary vessels. As this can precipitate massive hemorrhage, it is important to establish invasive arterial monitoring and large-bore intravenous access before anesthesia induction.3The authors declare no competing interests.

Effect of the VivaSight double-lumen tube on the incidence of hypoxaemia during one-lung ventilation in patients undergoing thoracoscopic surgery: a study protocol for a prospective randomised controlled trial

IntroductionA double-lumen tube (DLT) is a traditional one-lung ventilation tool that needs to be positioned under the guidance of a fibreoptic bronchoscope or auscultation. The placement is complex, and poor...

Preoperative lung ultrasound for confirming the double-lumen endotracheal tube position for one-lung ventilation: A systematic review and meta-analysis

ObjectivesInsertion of a double-lumen endotracheal tube (DLT) is the most commonly used method for one-lung ventilation (OLV). This meta-analysis was aimed at investigating the performance of lung ultrasound in assessing the DLT position in OLV. MethodsElectronic databases were searched for related trials from inception to October 2022. The primary outcome was the performance of ultrasound or clinical evaluation in confirming the correctness of the DLT position, using fiberoptic bronchoscopy or intraoperative direct visualization of lung collapse as the gold standard. The secondary outcome was the time required to confirm or adjust the DTL position. ResultsFive randomized controlled trials and three observational studies involving 771 patients were included in the meta-analysis. The pooled sensitivity and specificity of ultrasound were 0.93 (95% confidence interval [CI]: 0.79–0.98) and 0.61 (95% CI: 0.41–0.77), respectively, while those of clinical evaluation were 0.93 (95% CI: 0.73–0.99) and 0.35 (95% CI: 0.25–0.47), respectively. The pooled procedure duration was 122.27 s (95% CI: 20.85–223.69) with ultrasound and 112.03 s (95% CI: 95.30–128.76) with clinical evaluation. The area under the curve for discriminating the DLT position was 0.86 (95% CI: 0.82–0.88) for ultrasound and 0.52 (95% CI: 0.48–0.57) for clinical evaluation. ConclusionsCompared to clinical evaluation, ultrasound has a similar sensitivity but a better specificity for confirming the correctness of the DLT position. Ultrasound is an acceptable imaging tool for assessing DTL placement in OLV.

Videogestützte Doppellumentuben in der roboterassistierten Ösophaguschirurgie

Robot-assisted esophagectomies are still considered high-risk procedures requiring complex surgical and anesthesiological planning and coordination. The operative space during the thoracic operative part is created by one-lung ventilation. Due to special patient positioning and intraoperative repositioning maneuvers, however, access to patient airway or double-lumen tube manipulation, if necessary, is only possible to a certain extent. In this work, we present our experiences establishing a video-guided double-lumen tube for esophageal surgery. From our point of view, the use of video-guided double-lumen tubes is very suitable increasing patient safety and coordination in the operational team during esophagectomy.

Choosing the correct-sized adult double-lumen tube: Quest for the holy grail.

Appropriate size selection of double-lumen tubes (DLTs) for one-lung ventilation (OLV) in adults is still a humongous task. Several important factors are to be considered like patient height, gender, tracheal diameter, left main bronchial diameter, and cricoid cartilage transverse diameter. In addition to radiological assessment of the airway diameters, the manufacturing details of the particular DLT being used also play a significant role in size selection. Optimal positioning of the appropriately sized DLT is indispensable to avoid complications like airway trauma, cuff rupture, hypoxemia, and tube displacement. It is imperative to know whether the one-size-fits-all dictum holds for DLT size selection as claimed by certain studies. Further randomized studies are required for crystallizing standard protocols ascertaining the correct DLT size. This systematic review article highlights the various parameters employed for DLT size selection and explores the newer DLTs used for adult OLV.

Effect of Minimum Bronchial Cuff Volume of Left-Sided Double-Lumen Tube for One-Lung Ventilation on the Change in Bronchial Cuff Pressure during Lateral Positioning in Thoracic Surgery: A Prospective Observational Study

The minimum bronchial cuff volume (BCVmin) of a double-lumen tube (DLT) without air leaks during lung isolation may vary among individuals, and lateral positioning could increase the bronchial cuff pressure (BCP). We investigated the effect of initially established BCVmin (BCVi) on the change in BCP by lateral positioning. Seventy patients who underwent elective lung surgery were recruited and divided into two groups according to the BCVi obtained during anesthetic induction in each patient. Outcome analysis was conducted using data from 39 patients with a BCVi greater than 0 (BCVi > 0 group) and 27 with a BCVi of 0 (BCVi = 0 group). The primary outcome was a change in the value measured in the supine and lateral positions of the initially established BCP (BCPi; BCP at the time of BCVi injection), which was significantly larger in the BCVi > 0 group than in the BCVi = 0 group (1.5 (0.5-6.0) cmH2O vs. 0.0 (0.0-1.0) cmH2O; p < 0.001). BCVi was related to the left main bronchus (LMB) diameter (Spearman's rho = 0.676, p < 0.001) and the gap between the LMB diameter and the outer diameter of the bronchial cuff (Spearman's rho = 0.553, p < 0.001). Therefore, selecting a DLT size with a bronchial cuff that fits each patient's LMB may be useful in minimizing the change in BCP when performing lateral positioning during thoracic surgery. If the bronchial cuff requires unavoidable initial inflation, it is necessary to be aware that BCP may increase during lateral positioning and to monitor the BCP regularly if possible.

One-Lung Ventilation during Rigid Bronchoscopy Using a Single-Lumen Endotracheal Tube: A Descriptive, Retrospective Single-Center Study.

Using one-lung ventilation (OLV) through a single-lumen endotracheal tube (SLT) in the untreated lung during rigid bronchoscopy (RB) and jet ventilation, high oxygenation can be guaranteed, whilst procedures requiring thermal energy in the other lung are still able to be used. This pilot study aimed to examine the bronchoscopy-associated risks and feasibility of OLV using an SLT during RB in patients with malignant airway stenosis. All consecutive adult patients with endobronchial malignant lesions receiving OLV during RB from 1 January 2017 to 12 May 2021 were included. We assessed perioperative complications in 25 RBs requiring OLV. Bleeding grades 1, 2, and 3 complicated the procedure in two (8%), five (20%), and five (20%) patients, respectively. The median saturation of peripheral oxygen remained at 94% (p = 0.09), whilst the median oxygen supply did not increase significantly from 0 L/min to 2 L/min (p = 0.10) within three days after the bronchoscopy. The 30-day survival rate of the patients was 79.1% (95% CI 58.4-91.1%), all of whom reported an improvement in subjective well-being after the bronchoscopy. OLV using an SLT during RB could be a new treatment approach for endobronchial ablative procedures without increasing bronchoscopy-associated risks, allowing concurrent high-energy treatments.

Intraoperative Ventilator Management of the Critically Ill Patient.

Strategies for the intraoperative ventilator management of the critically ill patient focus on parameters used for lung protective ventilation with acute respiratory distress syndrome, preventing or limiting the deleterious effects of mechanical ventilation, and optimizing anesthetic and surgical conditions to limit postoperative pulmonary complications for patients at risk. Patient conditions such as obesity, sepsis, the need for laparoscopic surgery, or one-lung ventilation may benefit from intraoperative lung protective ventilation strategies. Anesthesiologists can use risk evaluation and prediction tools, monitor advanced physiologic targets, and incorporate new innovative monitoring techniques to develop an individualized approach for patients.

Systematic Review and Meta-Analysis of Efficiency and Safety of Double-Lumen Tube and Bronchial Blocker for One-Lung Ventilation.

One-lung ventilation is also used in some thoracic or cardiac surgery, vascular surgery and oesophageal procedures. We conducted a search of the literature for relevant studies in PubMed, Web of Science, Embase, Scopus and Cochrane Library. The final literature search was performed on 10 December 2022. Primary outcomes included the quality of lung collapse. Secondary outcome measures included: the success of the first intubation attempt, malposition rate, time for device placement, lung collapse and adverse events occurrence. Twenty-five studies with 1636 patients were included. Excellent lung collapse among DLT and BB groups was 72.4% vs. 73.4%, respectively (OR = 1.20; 95%CI: 0.84 to 1.72; p = 0.31). The malposition rate was 25.3% vs. 31.9%, respectively (OR = 0.66; 95%CI: 0.49 to 0.88; p = 0.004). The use of DLT compared to BB was associated with a higher risk of hypoxemia (13.5% vs. 6.0%, respectively; OR = 2.27; 95%CI: 1.14 to 4.49; p = 0.02), hoarseness (25.2% vs. 13.0%; OR = 2.30; 95%CI: 1.39 to 3.82; p = 0.001), sore throat (40.3% vs. 23.3%; OR = 2.30; 95%CI: 1.68 to 3.14; p < 0.001), and bronchus/carina injuries (23.2% vs. 8.4%; OR = 3.45; 95%CI: 1.43 to 8.31; p = 0.006). The studies conducted so far on comparing DLT and BB are ambiguous. In the DLT compared to the BB group, the malposition rate was statistically significantly lower, and time to tube placement and lung collapse was shorter. However, the use of DLT compared to BB can be associated with a higher risk of hypoxemia, hoarseness, sore throat and bronchus/carina injuries. Multicenter randomized trials on larger groups of patients are needed to draw definitive conclusions regarding the superiority of any of these devices.

Transcutaneous Carbon Dioxide Monitoring More Accurately Detects Hypercapnia than End-Tidal Carbon Dioxide Monitoring during Non-Intubated Video-Assisted Thoracic Surgery: A Retrospective Cohort Study

Transcutaneous carbon dioxide (PtcCO2) monitoring is known to be effective at estimating the arterial partial pressure of carbon dioxide (PaCO2) in patients with sedation-induced respiratory depression. We aimed to investigate the accuracy of PtcCO2 monitoring to measure PaCO2 and its sensitivity to detect hypercapnia (PaCO2 > 60 mmHg) compared to nasal end-tidal carbon dioxide (PetCO2) monitoring during non-intubated video-assisted thoracoscopic surgery (VATS). This retrospective study included patients undergoing non-intubated VATS from December 2019 to May 2021. Datasets of PetCO2, PtcCO2, and PaCO2 measured simultaneously were extracted from patient records. Overall, 111 datasets of CO2 monitoring during one-lung ventilation (OLV) were collected from 43 patients. PtcCO2 had higher sensitivity and predictive power for hypercapnia during OLV than PetCO2 (84.6% vs. 15.4%, p < 0.001; area under the receiver operating characteristic curve; 0.912 vs. 0.776, p = 0.002). Moreover, PtcCO2 was more in agreement with PaCO2 than PetCO2, indicated by a lower bias (bias ± standard deviation; -1.6 ± 6.5 mmHg vs. 14.3 ± 8.4 mmHg, p < 0.001) and narrower limit of agreement (-14.3-11.2 mmHg vs. -2.2-30.7 mmHg). These results suggest that concurrent PtcCO2 monitoring allows anesthesiologists to provide safer respiratory management for patients undergoing non-intubated VATS.

Hypoxemia in thoracoscopic lung resection surgery using a video double-lumen tube versus a conventional double-lumen tube: A propensity score-matched analysis.

Malposition of the double-lumen tubes (DLTs) may lead to hypoxemia during one-lung ventilation (OLV). Video double-lumen tubes (VDLTs) enable continuous observation of DLT position and avoid displacement. We aimed to investigate whether VDLTs could reduce the incidence of hypoxemia during OLV compared with conventional double-lumen tubes (cDLT) in thoracoscopic lung resection surgery. This was a retrospective cohort study. Adult patients who underwent elective thoracoscopic lung resection surgery and required VDLTs or cDLTs for OLV at Shanghai Chest Hospital from January 2019 to May 2021 were included. The primary outcome was the incidence of hypoxemia during OLV between VDLT and cDLT. Secondary outcomes included bronchoscopy use, the degree of PaO2 decline, and arterial blood gas indices. A total of 1,780 patients were finally analyzed in propensity score-matched cohorts (VDLT vs. cDLT 1:1 n = 890). The incidence of hypoxemia decreased from 6.5% (58/890) in cDLT group to 3.6% (32/890) in VDLT group (Relative Risk [RR]: 1.812, 95% CI: 1.19-2.76, p = 0.005). The use of bronchoscopy was reduced by 90% in VDLT group (VDLT 10.0% (89/890) vs. cDLT 100% (890/890), p < 0.001). PaO2 after OLV was 221 [136.0-325.0] mmHg in cDLT group compared to 234 [159.7-336.2] mmHg in VDLT group, p = 0.003. The percentage of PaO2 decline was 41.4 [15.4-61.9] % in cDLT group, while it was 37.7 [8.7-55.9] % in the VDLT group, p < 0.001. In patients who suffered from hypoxemia, there were no significant differences in arterial blood gas indices or the percentage of PaO2 decline. VDLTs reduce the incidence of hypoxemia and the use of bronchoscopy during OLV compared with cDLTs. VDLT may be a feasible option for thoracoscopic surgery.

Muscular tissue desaturation and pneumonia in patients receiving lung cancer surgery: a cohort study.

Post-operative pneumonia (POP) is a common complication of lung cancer surgery, and muscular tissue oxygenation is a root cause of post-operative complications. However, the association between muscular tissue desaturation and POP in patients receiving lung cancer surgery has not been specifically studied. This study aimed to investigate the potential use of intra-operative muscular tissue desaturation as a predictor of POP in patients undergoing lung cancer surgery. This cohort study enrolled patients (≥55 years) who had undergone lobectomy with one-lung ventilation. Muscular tissue oxygen saturation (SmtO2) was monitored in the forearm (over the brachioradialis muscle) and upper thigh (over the quadriceps) using a tissue oximeter. The minimum SmtO2 was the lowest intra-operative measurement at any time point. Muscular tissue desaturation was defined as a minimum baseline SmtO2 of <80% for >15 s. The area under or above the threshold was the product of the magnitude and time of desaturation. The primary outcome was the association between intra-operative muscular tissue desaturation and POP within seven post-operative days using multivariable logistic regression.The secondary outcome was the correlation between SmtO2 in the forearm and that in the thigh. We enrolled 174 patients. The overall incidence of muscular desaturation (defined as SmtO2 < 80% in the forearm at baseline) was approximately 47.1% (82/174). The patients with muscular desaturation had a higher incidence of pneumonia than those without desaturation (28.0% [23/82] vs. 12.0% [11/92]; P = 0.008). The multivariable analysis revealed that muscular desaturation was associated with an increased risk of pneumonia (odds ratio: 2.995, 95% confidence interval: 1.080-8.310, P = 0.035) after adjusting for age, American Society of Anesthesiologists status, Assess Respiratory Risk in Surgical Patients in Catalonia score, smoking, use of peripheral nerve block, propofol, and study center. Muscular tissue desaturation, defined as a baseline SmtO2 < 80% in the forearm, may be associated with an increased risk of POP. No. ChiCTR-ROC-17012627.

Effect of one-lung ventilation on the correlation between left and right cerebral saturation

BackgroundTo investigate if the correlation between left and right cerebral tissue oxygen saturation (SctO2) was affected by one-lung ventilation (OLV) in patients undergoing lung cancer surgery.MethodsPatients who underwent surgery for lung cancer were enrolled. Left and right SctO2 were collected during anesthesia. The primary outcome was the correlation between left and right SctO2 at 30 min after OLV which was analysed by Pearson correlation and linear regression model. Secondary outcomes included the trend of left–right SctO2 change over the first 30 min after OLV, correlation of left–right SctO2 during OLV for each patient; maximal difference between left–right SctO2 and its relationship with postoperative delirium.ResultsLeft–right SctO2 was moderately correlated at baseline (r = 0.690, P < 0.001) and poorly correlated at 30 min after OLV (r = 0.383, P < 0.001) in the Pearson correlation analysis. Linear regression analysis showed a poor correlation between left and right SctO2 at 30 min after OLV (r = 0.323, P < 0.001) after adjusting for confounders. The linear mixed model showed a change in left–right SctO2 over the first 30 min after OLV that was statistically significant (coefficient, -0.042; 95% CI, -0.070–-0.014; P = 0.004). For the left–right SctO2 correlation during OLV in each patient, 62.9% (78/124) patients showed a strong correlation, 19.4% (24/124) a medium correlation, and the rest a poor correlation. The maximal difference between the left and right SctO2 was 13.5 (9.0, 20.0). Multivariate analysis showed that it was not associated with delirium (odds ratio [OR], 1.023; 95% CI, 0.963–1.087; P = 0.463).ConclusionsThe correlation between left and right SctO2 was affected by one-lung ventilation in patients undergoing lung cancer surgery. This result indicates the requirement of bilateral SctO2 monitoring to reflect brain oxygenation.Trial registrationThis study was a secondary analysis of a cohort study approved by the Clinical Research Review Board of Peking University First Hospital (#2017–1378) and was registered in the Chinese Clinical Trial Registry on 10/09/2017 (http://www.chictr.org.cn, ChiCTR-ROC-17012627).

Effects of Ketamine Infusion on Oxygenation in Patients with Chronic Obstructive Pulmonary Disease Undergoing Lung Cancer Surgery.

Ketamine changes respiratory mechanics, provides airway relaxation, and alleviates bronchospasm in patients with pulmonary disease. This study investigated the effect of a continuous infusion of ketamine during thoracic surgery on arterial oxygenation (PaO2/FiO2) and the shunt fraction (Qs/Qt) in patients with chronic obstructive pulmonary disease. Thirty patients older than 40 years, diagnosed with chronic obstructive pulmonary disease, and undergoing lobectomy were recruited for this study. Patients were allocated randomly to 1 of 2 groups. At the induction of anaesthesia, group K received intravenous (iv) 1 mg kg-1 ketamine as a bolus and followed by 0.5 mg kg-1 h-1 infusion until the end of the operation. Group S received the same amount of 0.9% saline as a bolus at induction and followed by a 0.5-mL kg-1 h-1 infusion of 0.9% saline until the end of the operation. PaO2 and PaCO2 values, FiO2 levels, PaO2/FiO2 ratio, peak airway pressure (Ppeak), plateau airway pressure (Pplat), dynamic compliance, and shunt fraction (Qs/Qt) were recorded during two-lung ventilation as a baseline and at 30 (one-lung ventilation, OLV-30) and 60 (OLV-60) minutes during one-lung ventilation. PaO2, PaCO2, PaO2/FiO2 values, and Qs/Qt ratio were similar between the 2 groups at OLV-30 minute (P = .36, P = .29, P = .34). However, at OLV-60 minute, PaO2, PaO2/FiO2 values were significantly increased, and Qs/Qt ratios were significantly decreased in group K than in group S (P = .016, P = .011, P = .016). Our data suggest that a continuous infusion of ketamine and desflurane inhalation in patients with chronic obstructive pulmonary disease during one-lung ventilation increase arterial oxygenation (PaO2/FiO2) and decrease shunt fraction.

A combination of supraglottic airway and bronchial blocker for one-lung ventilation in infants undergoing thoracoscopic surgery

ObjectivesOne-lung ventilation (OLV) for children under the age of two years is difficult. The authors hypothesize that a combination of a supraglottic airway (SGA) device and intraluminal placement of a bronchial blocker (BB) may provide an appropriate choice. DesignA prospective method-comparison study. SettingSecond Affiliated Hospital of Xi'an Jiaotong University, China. Participants120 patients under the age of two years undergoing thoracoscopic surgery with OLV. InterventionsParticipants were randomly assigned to receive intraluminal placement of BB with SGA (n = 60) or extraluminal placement of BB with endotracheal tube (ETT) (n = 60) for OLV. Measurements and main resultsThe primary outcome was the length of postoperative hospitalization stay. The secondary outcomes were the basic parameters of OLV and investigator-defined severe adverse events. The postoperative hospitalization stay was 6 days (interquartile range, IQR 4–9) in SGA plus BB group compared with 9 days (IQR 6–13) in ETT plus BB group (P = 0.034). The placement and positioning duration of SGA plus BB was 64 s (IQR 51–75) compared with 132 s (IQR 117–152) of ETT plus BB (P = 0.001). The values of leukocyte (WBC) and C-reactive protein (CRP) of SGA plus BB group on the first day of post-operation were 9.8 × 109/L (IQR 7.4–14.5) and 15.1 mg/L (IQR 12.5–17.3) compared with 13.6 × 109/L (IQR 10.8–17.1) and 19.6 mg/L (IQR 15.0–23.5) of ETT plus BB group (P = 0.022 and P = 0.014). ConclusionThere were few if any significant adverse events in the intervention group (SGA plus BB) for OLV in children under the age of two years, and this method seems worthy of clinical application. Meanwhile, the mechanism for this novel technique to shorten the length of postoperative hospitalization stay needs to be further explored.

Amlodipine and Atropine for Hypoxia During One-Lung Ventilation: A Case Report.

Anesthetists are concerned about the causes and management of hypoxia during one-lung ventilation (OLV). Here, we report a hypoxic case during OLV and video-assisted thoracic surgery (VATS) for pulmonary lobectomy. The preoperative management of hypertension with amlodipine was considered to be responsible for the hypoxia. As a calcium channel blocker, amlodipine may inhibit hypoxic pulmonary vasoconstriction (HPV) and contribute to the reduction of the ventilation/perfusion ratio (or V/Q ratio). The hypoxia efficiently was treated by atropine, where both tracheal effects and the enhancement of HPV through muscarinic receptor blocking may work. For patients undertaking OLV, the effects of calcium channel blockers as a potential cause for hypoxemia should be paid attention to, where atropine administration may be of clinical benefit. One-lung ventilation (OLV) generally is used during anesthesia for thoracic surgeries. For OLV, a double-lumen tracheal tube (DLT) is used to realize lung separation in the airway. This technique is essential because it facilitates the surgical performance as well as isolates a healthy lung from the pathologic one. However, there are some concerns for OLV during anesthesia, where hypoxemia is commonly seen. There are many causes for hypoxemia during OLV. These include, for example, reduced oxygen stores due to the collapse of the non-ventilation lung, ventilation-perfusion mismatch induced by both lateral positions, and decrease in elastic recoil leading to more atelectasis. Accordingly, management of hypoxemia during OLV generally have been applied. Increase fraction of inspiration O2 (Fi O2) to 1, double checking the position of DLT, applying positive end expiratory pressure (PEEP), optimizing cardiac output (CO) all have been proven to be effective. Here, we report an efficiently treated hypoxemia case using atropine during video-assisted thoracic surgery (VATS) for pulmonary lobectomy. Preoperative medication of amlodipine may contribute to the hypoxemia through attenuating HPV during OLV, which may be antagonized by possible HPV augmentation of atropine. Further investigation is therefore suggested.

Effect of intubation in the lateral position under general anesthesia induction on the position of double-lumen tube placement in patients undergoing unilateral video-assisted thoracic surgery: study protocol for a prospective, single-center, parallel group, randomized, controlled trial

BackgroundThe double-lumen tube (DLT) is an essential equipment for thoracic anesthesia and the precise position of DLT placement is particularly important for anesthesia and surgery. However, the incidence of DLT malposition remains high and it leads to lung isolation failure and hypoxemia during one-lung ventilation. This trial aims to explore the clinical application and efficacy of intubation in the lateral position under general anesthesia induction to reduce the incidence of DLT malposition in patients undergoing unilateral video-assisted thoracic surgery (VATS).MethodsIn this prospective, single-center, parallel group, randomized, controlled trial, we will recruit 108 patients, aged 18–80 years, scheduled for elective unilateral VATS with DLT intubation under general anesthesia, and they will be randomly assigned to two groups: a lateral DLT intubation group (group L) and a conventional supine DLT intubation group (group C). The left-sided DLT will be used to intubate in patients of both groups. The position of DLT will be confirmed and adjusted by using the fiberoptic bronchoscopy (FOB). The primary outcome is the incidence of DLT malposition observed via the FOB, and the secondary outcomes include the time of intubation, the frequency and duration of re-adjustments of DLT placement under FOB, whether to re-intubate, intraoperative vital signs, and postoperative recovery.DiscussionAccurate DLT positioning is crucially important for thoracic surgery, but the incidence of DLT malposition is still high in the present clinical practice of thoracic anesthesia. This trial aims to investigate whether lateral DLT intubation can reduce the incidence of DLT malposition, with more stable intraoperative vital signs and less postoperative complications.Trial registrationThe study protocol was registered at Chinese Clinical Trial Registry (http://www.chictr.org.cn) with registration number: ChiCTR2200060794 on June 11, 2022.