Single-Lung Ventilation in Infants for Surgical Repair of Coarctation of The Aorta Without Cardiopulmonary Bypass.

OBJECTIVE: To investigate the effect of improving the operative field and postoperative atelectasis of single-lung ventilation (SLV) in the surgical repair of coarctation of the aorta (CoA) in infants without the use of cardiopulmonary bypass (CPB). METHODS: This was a retrospective cohort study. The clinical data of 28 infants (aged 1 to 4 months, weighing between 4.2 and 6 kg) who underwent surgical repair of CoA without CPB from January 2019 to May 2022 were analyzed. Fourteen infants received SLV with a bronchial blocker (Group S), and the other 14 infants received routine endotracheal intubation and bilateral lung ventilation (Group R). RESULTS: In comparison to Group R, Group S exhibited improved exposure of the operative field, a lower postoperative atelectasis score (P<0.001), reduced prevalence of hypoxemia (P=0.01), and shorter durations of operation, mechanical ventilation, and ICU stay (P=0.01, P<0.001, P=0.03). There was no difference in preoperative information or perioperative respiratory and circulatory indicators before SLV, 10 minutes after SLV, and 10 minutes after the end of SLV between the two groups (P>0.05). Intraoperative bleeding, intraoperative positive end-expiratory pressure (PEEP), and systolic pressure gradient across the coarctation after operation were also not different between the two groups (P>0.05). CONCLUSION: This study demonstrates that employing SLV with a bronchial blocker is consistent with enhanced operative field, reduced operation duration, lower prevalence of intraoperative hypoxemia, and fewer postoperative complications during the surgical repair of CoA in infants without the use of CPB.

Effects of small-dose S-ketamine on anesthesia-induced atelectasis in patients undergoing general anesthesia accessed by lung ultrasound: study protocol for a randomized, double-blinded controlled trial.

BACKGROUND: Atelectasis after anesthesia induction in most patients undergoing general anesthesia may lead to postoperative pulmonary complications (PPCs) and affect postoperative outcomes. However, there is still no existing effective method used for the prevention of perioperative atelectasis. S-ketamine may prevent atelectasis due to airway smooth muscle relaxation and anti-inflammatory effects. Lung ultrasound is a portable and reliable bedside imaging technology for diagnosing anesthesia-induced atelectasis. The primary objective of this study is to assess whether a small dose of S-ketamine can reduce the incidence of atelectasis after intubation, and further investigate the effects of preventing the early formation of perioperative atelectasis and PPCs. METHODS: This is a single-institution, prospective, randomized controlled, parallel grouping, and double-blind study. From October 2020 to March 2022, 100 patients (18-60 years old) scheduled for elective surgery will be recruited from Beijing Tiantan Hospital, Capital Medical University, and randomly assigned to the S-ketamine group (group 1) and the normal saline group (group 2) at a ratio of 1:1. The label-masked agents will be administered 5 min before induction, and all patients will undergo a standardized general anesthesia protocol. Related data will be collected at three time points: after radial artery puncture (T1), 15 min after tracheal intubation (T2), and before extubation (T3). The primary outcome will be the total lung ultrasound scores (LUS) at T2. Secondary outcomes will include LUS in six chest regions at T2, total LUS at T3, arterial blood gas analysis results (PaCO2, PaO2) and PaO2/FiO2 at T2 and T3, and plateau pressure (Pplat) and dynamic lung compliance (Cdyn) at T2 and T3. The incidence of postoperative complications associated with S-ketamine and PPCs at 2 h and 24 h after surgery will be recorded. DISCUSSION: This trial aims to explore whether a simple and feasible application of S-ketamine before the induction of general anesthesia can prevent atelectasis. The results of this study may provide new ideas and direct clinical evidence for the prevention and treatment of perioperative pulmonary complications during anesthesia. TRIAL REGISTRATION: ClinicalTrials.gov NCT04745286. Registered on February 9, 2021.

Positive end-expiratory pressure during one-lung ventilation for preventing atelectasis after video-assisted thoracoscopic surgery: a triple-arm, randomized controlled trial.

BACKGROUND: There is little evidence regarding the benefits of lung-protective ventilation in patients undergoing one-lung ventilation for thoracic surgery. This study aimed to determine the optimal level of positive end-expiratory pressure (PEEP) during one-lung ventilation for minimizing postoperative atelectasis through lung ultrasonography. METHODS: A total of 142 adult patients scheduled for video-assisted thoracoscopic surgery at Seoul National University Hospital between May 2019 and February 2020 were enrolled in this study. Patients were randomly assigned to different groups: 1) PEEP 3 cmH2O group; 2) PEEP 6 cmH2O group; and 3) PEEP 9 cmH2O group during one-lung ventilation. The lung ultrasound score was used to evaluate lung aeration using ultrasonography 1 hour after surgery. RESULTS: The 1-hour post-surgery lung ultrasound scores were 8.1±2.5, 6.8±2.6, and 5.9±2.6 in the PEEP 3, 6, and 9 cmH2O groups, respectively (P<0.001). The PEEP 3 cmH2O group showed significantly higher lung ultrasound scores than the PEEP 6 (adjusted P=0.034) and 9 cmH2O groups (adjusted P<0.001). The PaO2/FiO2 ratio measured at 10 minutes after the end of one-lung ventilation was significantly lower in the PEEP 3 cmH2O group (392 [331 to 469]) than the PEEP 6 cmH2O (458 [384 to 530], adjusted P=0.018) or PEEP 9 cmH2O groups (454 [374 to 522], adjusted P=0.016). CONCLUSIONS: Although the optimal level of PEEP during one-lung ventilation was not determined, the application of higher PEEP can prevent aeration loss in the ventilated lung after video-assisted thoracoscopic surgery under one-lung ventilation.

Dexmedetomidine improves pulmonary outcomes in thoracic surgery under one-lung ventilation: A meta-analysis.

INTRODUCTION: Dexmedetomidine improves intrapulmonary shunt in thoracic surgery and minimizes inflammatory response during one-lung ventilation (OLV). However, it is unclear whether such benefits translate into less postoperative pulmonary complications (PPCs). Our objective was to determine the impact of dexmedetomidine on the incidence of PPCs after thoracic surgery. METHODS: Major databases were used to identify randomized trials that compared dexmedetomidine versus placebo during thoracic surgery in terms of PPCs. Our primary outcome was atelectasis within 7 days after surgery. Other specific PPCs included hypoxemia, pneumonia, and acute respiratory distress syndrome (ARDS). Secondary outcome included intraoperative respiratory mechanics (respiratory compliance [Cdyn]) and postoperative lung function (forced expiratory volume [FEV1]). Random effects models were used to estimate odds ratios (OR). RESULTS: Twelve randomized trials, including 365 patients in the dexmedetomidine group and 359 in the placebo group, were analyzed in this meta-analysis. Patients in the dexmedetomidine group were less likely to develop postoperative atelectasis (2.3% vs 6.8%, OR 0.42, 95%CI 0.18-0.95, P = 0.04; low certainty) and hypoxemia (3.4% vs 11.7%, OR 0.26, 95%CI 0.10-0.68, P = 0.01; moderate certainty) compared to the placebo group. The incidence of postoperative pneumonia (3.2% vs 5.8%, OR 0.57, 95%CI 0.25-1.26, P = 0.17; moderate certainty) or ARDS (0.9% vs 3.5%, OR 0.39, 95%CI 0.07-2.08, P = 0.27; moderate certainty) was comparable between groups. Both intraoperative Cdyn and postoperative FEV1 were higher among patients that received dexmedetomidine with a mean difference of 4.42 mL/cmH2O (95%CI 3.13-5.72) and 0.27 L (95%CI 0.12-0.41), respectively. CONCLUSION: Dexmedetomidine administration during thoracic surgery may potentially reduce the risk of postoperative atelectasis and hypoxemia. However, current evidence is insufficient to demonstrate an effect on pneumonia or ARDS.

Lung ultrasound-guided best positive end-expiratory pressure in neonatal anesthesia: a proposed randomized, controlled study.

BACKGROUND: Atelectasis is a common complication in neonatal anesthesia. Lung ultrasound (LUS) can be used intraoperatively to evaluate and recognize atelectatic lung areas. Hypotheses for the study are: (1) The use of LUS to guide choice of best positive end-expiratory pressure (PEEP) can lead to reduction of FiO2 to achieve same saturations of oxygen (SpO2). (2) In a less de-recruited lung, there will be less postoperative pulmonary complications. (3) Static respiratory system compliance could be different. (4) Hemodynamic parameters and amount of fluids infused or need for vasopressors intraoperatively could be different. METHODS: We propose a randomized controlled trial that compares standard PEEP settings with LUS-guided PEEP choice in patients under 2 months of age undergoing general anesthesia. RESULTS: The primary aim is to determine whether LUS-guided PEEP choice in neonatal anesthesia, compared to standard PEEP choice, can lead to reduction of FiO2 applied to the ventilatory setting in order to maintain same SpO2s. Secondary aims are to determine whether patients treated with LUS-guided PEEP will develop less postoperative pulmonary complications, will have a significant difference in hemodynamic parameters and amount of fluids or vasopressors infused, and in static respiratory system compliance. CONCLUSIONS: We expect a significant reduction of FiO2 in LUS-guided ventilation. IMPACT: Lung atelectasis is extremely common in neonatal anesthesia, because of the physiology of the neonatal lung and chest wall and leads to hypoxemia, being a lung area with a perfusion/ventilation mismatch. Raising inspired fraction of oxygen can overcome temporarily hypoxemia but oxygen is a toxic compound for newborns. Lung ultrasound (LUS) can detect atelectasis at bedside and be used to optimize ventilator settings including choice of positive end-expiratory pressure (PEEP). This randomized controlled trial (RCT) aims at demonstrating that LUS-guided choice of best PEEP during neonatal anesthesia can lead to reduction of inspired fractions of oxygen to keep same peripheral saturations SpO2.

Pulmonary expansion manoeuvres compared to usual care on ventilatory mechanics, oxygenation, length of mechanical ventilation and hospital stay, extubation, atelectasis, and mortality of patients in mechanical ventilation: A randomized clinical trial.

Pulmonary expansion manoeuvres are therapeutic techniques used to prevent and reverse atelectasis; however, no randomized controlled trials have provided evidence supporting the use of this intervention among individuals on mechanical ventilation. OBJECTIVE: To evaluate the effects of chest compression-decompression and chest block manoeuvres compared to usual care among patients on mechanical ventilation. METHODS: The current study was a randomized clinical trial of adult subjects on mechanical ventilation for 12 to 48 hours. The control group received usual care (passive or active mobilization, manoeuvres for airway clearance and tracheal aspiration). The intervention group received usual care plus two lung expansion manoeuvres, i.e., chest decompression and chest block, while remaining on mechanical ventilation. Assessments were performed before and after usual care, immediately after the intervention and 30 minutes after the intervention. The primary outcome was static compliance. The secondary outcomes were the incidence of atelectasis, dynamic compliance, airway resistance, driving pressure, oxygenation, duration of mechanical ventilation, extubation success, length of hospital and ICU stay, and mortality. RESULTS: Fifty-one participants (67±15 years old, 53% men, 26 in the control group and 25 in the intervention group) were evaluated. No differences in static compliance were observed between groups (intervention minus control) before and after expansion manoeuvres [3.64 ml/cmH2O (95% CI: -0.36-7.65, p = 0.074)]. Peripheral oxygen saturation differed between groups before and after expansion manoeuvres, with more favourable outcome observed in the control group [-1.04% (95% CI: -1.94 --0.14), p = 0.027]. No differences were found in other outcomes. CONCLUSION: Chest compression-decompression and chest block manoeuvres did not improve ventilatory mechanics, the incidence of atelectasis, oxygenation, the duration of mechanical ventilation, the length of stay in the ICU and hospital, or mortality in individuals on mechanical ventilation. The findings of this study can be valuable for guiding evidence-based clinical practice and developing a therapeutic approach that provides real benefits for this population.

Evaluation of the Effect of Pressure-Controlled Ventilation-Volume Guaranteed Mode vs. Volume-Controlled Ventilation Mode on Atelectasis in Patients Undergoing Laparoscopic Surgery: A Randomized Controlled Clinical Trial.

Background and Objectives: Laparoscopic surgery, which results in less bleeding, less postoperative pain, and better cosmetic results, may affect the lung dynamics via the pneumoperitoneum. After laparoscopic surgery, atelectasis develops. The primary aim of the present study is to demonstrate the effects of two different ventilation modes on the development of atelectasis using lung ultrasound, and the secondary outcomes include the plateau pressure, peak inspiratory pressure, and compliance differences between the groups. Materials and Methods: In this study, 62 participants aged 18-75 years undergoing laparoscopic cholecystectomy were enrolled. The patients were randomly assigned into two groups: the volume-controlled ventilation (VCV) group (group V) or the pressure-controlled-volume guaranteed ventilation (PCV-VG) group (group PV). The lung ultrasound score (LUS) was obtained thrice: prior to induction (T1), upon the patient's initial arrival in the recovery room (T2), and just before departing the recovery unit (T3). The hemodynamic data and mechanical ventilation parameters were recorded at different times intraoperatively. Results: The LUS score was similar between the groups at all the times. The change in the LUS score of the right lower anterior chest was statistically higher in the VCV group than the PCV group. The peak inspiratory pressure (PIP) was found to be statistically higher in the V group than the PV group five minutes after induction (T5) (20.84 ± 4.32 p = 0.021). The plateau pressure was found to be higher in the V group than the PV group at all times (after induction (Tind) 17.29 ± 5.53 p = 0.004, (T5) 17.77 ± 4.89 p = 0.001, after pneumoperitoneum (TPP) 19.71 ± 4.28 p = 0.002). Compliance was found to be statistically higher in the PV group than the V group at all times ((Tind) 48.87 ± 15.37 p = 0.011, (T5) 47.94 ± 13.71 p = 0.043, (TPP) 35.65 ± 6.90 p = 0.004). Before and after the pneumoperitoneum, the compliance was determined to be lower in the V group than the PV group, respectively (40.68 ± 13.91 p = 0.043, 30.77 ± 5.73 p = 0.004). Conclusions: LUS score was similar between groups at all times. The PCV-VG mode was superior to the VCV mode in providing optimal ventilatory pressures and maintaining high dynamic compliance in patients undergoing laparoscopic abdominal surgery.

Effect of high-frequency oscillation on reduction of atelectasis in perioperative patients: a prospective randomized controlled study.

BACKGROUND: Atelectasis affects approximately 90% of anaesthetized patients, with laparoscopic surgery and pneumoperitoneum reported to exacerbate this condition. High-frequency oscillation therapy applies continuous positive pressure pulses to oscillate the airway, creating a pressure difference in small airways obstructed by secretions. This process helps reduce peak airway pressure, open small airways, and decrease atelectasis incidence, while also facilitating respiratory tract clearance. This study examines the efficacy of high-frequency oscillation on reduction of atelectasis in laparoscopic cholecystectomy (LC) patients under general anaesthesia, evaluated using lung ultrasound. METHODS: Sixty-four patients undergoing laparoscopic cholecystectomy were randomly divided into a control group and a high-frequency oscillation (HFO) group. Both groups underwent total intravenous anaesthesia under invasive arterial monitoring. The HFO group received a 10-minute continuous high-frequency oscillation therapy during surgery, while the control group received no intervention. Lung ultrasound evaluations were performed three times: five minutes post-intubation (T1), at the end of the surgery (T2), and before leaving the Post-Anaesthesia Care Unit (PACU; T3). Blood gas analysis was performed twice: prior to induction with no oxygen supply and before PACU discharge (oxygen supply off). RESULTS: The HFO group displayed a significantly lower incidence of atelectasis at T3 (57.5% vs. 90.3%, OR 6.88, 95%CI (1.74 to 27.24)) compared to the control group. Moreover, the HFO group's PaO2 levels remained consistent with baseline levels before PACU discharge, unlike the control group. Although there was no significant difference in LUS scores between the groups at T1 (8.56 ± 0.15 vs. 8.19 ± 0.18, p = 0.1090), the HFO group had considerably lower scores at T2 (13.41 ± 0.17 vs.7.59 ± 0.17, p < 0.01) and T3 (13.72 ± 0.14 vs.7.25 ± 0.21, p < 0.01). CONCLUSION: Our study indicates that high-frequency oscillation effectively reduces atelectasis in patients undergoing laparoscopic cholecystectomy. Additionally, it can mitigate the decline in oxygen partial pressure associated with atelectasis.

Individualised positive end-expiratory pressure titrated intra-operatively by electrical impedance tomography optimises pulmonary mechanics and reduces postoperative atelectasis: A randomised controlled trial.

BACKGROUND: A protective intra-operative lung ventilation strategy has been widely recommended for laparoscopic surgery. However, there is no consensus regarding the optimal level of positive end-expiratory pressure (PEEP) and its effects during pneumoperitoneum. Electrical impedance tomography (EIT) has recently been introduced as a bedside tool to monitor lung ventilation in real-time. OBJECTIVE: We hypothesised that individually titrated EIT-PEEP adjusted to the surgical intervention would improve respiratory mechanics during and after surgery. DESIGN: Randomised controlled trial. SETTING: First Medical Centre of Chinese PLA General Hospital, Beijing. PATIENTS: Seventy-five patients undergoing robotic-assisted laparoscopic hepatobiliary and pancreatic surgery under general anaesthesia. INTERVENTIONS: Patients were randomly assigned 2 : 1 to individualised EIT-titrated PEEP (PEEPEIT; n = 50) or traditional PEEP 5 cmH2O (PEEP5 cmH2O; n = 25). The PEEPEIT group received individually titrated EIT-PEEP during pneumoperitoneum. The PEEP5 cmH2O group received PEEP of 5 cmH2O during pneumoperitoneum. MAIN OUTCOME MEASURES: The primary outcome was respiratory system compliance during laparoscopic surgery. Secondary outcomes were individualised PEEP levels, oxygenation, respiratory and haemodynamic status, and occurrence of postoperative pulmonary complications (PPCs) within 7 days. RESULTS: Compared with PEEP5 cmH2O, patients who received PEEPEIT had higher respiratory system compliance (mean values during surgery of 44.3 ±â€Š11.3 vs. 31.9 ±â€Š6.6, ml cmH2O-1; P < 0.001), lower driving pressure (11.5 ±â€Š2.1 vs. 14.0 ±â€Š2.4 cmH2O; P < 0.001), better oxygenation (mean PaO2/FiO2 427.5 ±â€Š28.6 vs. 366.8 ±â€Š36.4; P = 0.003), and less postoperative atelectasis (19.4 ±â€Š1.6 vs. 46.3 ±â€Š14.8 g of lung tissue mass; P = 0.003). Haemodynamic values did not differ significantly between the groups. No adverse effects were observed during surgery. CONCLUSION: Individualised PEEP by EIT may improve intra-operative pulmonary mechanics and oxygenation without impairing haemodynamic stability, and decrease postoperative atelectasis. TRIAL REGISTRATION: Chinese Clinical Trial Registry (www.chictr.org.cn) identifier: ChiCTR2100045166.

Effects of 30% vs. 60% inspired oxygen fraction during mechanical ventilation on postoperative atelectasis: a randomised controlled trial.

BACKGROUND: There is the ongoing debate over the effect of inspired oxygen fraction (FiO2) during mechanical ventilation on postoperative atelectasis. We aimed to compare the effects of low (30%) and moderate (60%) FiO2 on postoperative atelectasis. The hypothesis of the study was that 30% FiO2 during mechanical ventilation could reduce postoperative atelectasis volume compared with 60% FiO2. METHODS: We performed a randomized controlled trial with 120 patients. Subjects were randomly assigned to receive 30% or 60% FiO2 during mechanical ventilation in a 1:1 ratio. The primary outcome was the percentage of postoperative atelectasis volume in the total lung measured using chest CT within 30 min after extubation. The secondary outcomes included different aeration region volumes, incidence of clinically significant atelectasis, and oxygenation index. RESULTS: In total, 113 subjects completed the trial, including 55 and 58 subjects in the 30% and 60% FiO2 groups, respectively. The percentage of the postoperative atelectasis volume in the 30% FiO2 group did not differ from that in the 60% FiO2 group. Furthermore, there was no significant difference in the atelectasis volume between the two groups after the missing data were imputed by multiple imputation. Additionally, there were no significant differences in the volumes of the over-aeration, normal-aeration, and poor-aeration regions between the groups. No significant differences in the incidence of clinically significant atelectasis or oxygenation index at the end of surgery were observed between the groups. CONCLUSIONS: Compared with 60% FiO2, the use of 30% FiO2 during mechanical ventilation does not reduce the postoperative atelectasis volume. TRIAL REGISTRATION: Chinese Clinical Trial Registry ( http://www.chictr.org.cn ). Identifier: ChiCTR1900021635. Date: 2 March 2019. Principal invetigator: Weidong Gu.

Arterial partial pressure of oxygen as a marker of airway closure does not correlate with the efficacy of pre-oxygenation: A prospective cohort study.

BACKGROUND: The prerequisites for the early formation of anaesthesia-related atelectasis are pre-oxygenation with its resulting high alveolar oxygen content, and airway closure. Airway closure increases with age, so it seems counterintuitive that atelectasis formation during anaesthesia does not. One proposed explanation is that pre-oxygenation is impaired in the elderly by airway closure present in the waking state. The extent of airway closure cannot be assessed at the bedside, but arterial partial pressure of oxygen ( Pa O 2 ) as a surrogate variable of the resulting ventilation to perfusion mismatch can. OBJECTIVE: The primary aim was to test the hypothesis that a decreased efficacy of pre-oxygenation, measured as the fraction of end-tidal oxygen (F E' O 2 ) after 3 min of pre-oxygenation, correlates with decreased Pa O 2 on room air. We also re-investigated the influence on F E' O 2 by age. DESIGN: Prospective observational study. SETTING: Two regional hospitals, Västerås and Köping County Hospitals, Västmanland, Sweden, between 30 October 2018 and 17 September 2021. PARTICIPANTS: We included 120 adults aged 40 to 79 years presenting for elective noncardiac surgery. INTERVENTION: An arterial blood gas was sampled before commencing pre-oxygenation. RESULTS: No linear correlation was found between F E' O 2 at 3 min and Pa O 2 or age (Pearson's r  = -0.038, P  = 0.684; and Pearson's r  = -0.113, P  = 0.223, respectively). The mean ±â€ŠSD F E' O 2 at 3 min for the population studied was 0.87 ±â€Š0.05. CONCLUSION: The lack of correlation between F E' O 2 at 3 min and Pa O 2 or age during pre-oxygenation has implications for further studies concerning the interaction between airway closure and atelectasis. After 3 min of pre-oxygenation, F E' O 2 , even in the elderly, indicated a high enough alveolar oxygen concentration to promote atelectasis after induction, therefore, it is still unclear why atelectasis formation diminishes after middle age. TRIAL REGISTRATION: ClinicalTrials.gov NCT03395782.

Individualized Positive End-expiratory Pressure on Postoperative Atelectasis in Patients with Obesity: A Randomized Controlled Clinical Trial.

BACKGROUND: Individualized positive end-expiratory pressure (PEEP) guided by dynamic compliance improves oxygenation and reduces postoperative atelectasis in nonobese patients. The authors hypothesized that dynamic compliance-guided PEEP could also reduce postoperative atelectasis in patients undergoing bariatric surgery. METHODS: Patients scheduled to undergo laparoscopic bariatric surgery were eligible. Dynamic compliance-guided PEEP titration was conducted in all patients using a downward approach. A recruitment maneuver (PEEP from 10 to 25 cm H2O at 5-cm H2O step every 30 s, with 15-cm H2O driving pressure) was conducted both before and after the titration. Patients were then randomized (1:1) to undergo surgery under dynamic compliance-guided PEEP (PEEP with highest dynamic compliance plus 2 cm H2O) or PEEP of 8 cm H2O. The primary outcome was postoperative atelectasis, as assessed with computed tomography at 60 to 90 min after extubation, and expressed as percentage to total lung tissue volume. Secondary outcomes included Pao2/inspiratory oxygen fraction (Fio2) and postoperative pulmonary complications. RESULTS: Forty patients (mean ± SD; 28 ± 7 yr of age; 25 females; average body mass index, 41.0 ± 4.7 kg/m2) were enrolled. Median PEEP with highest dynamic compliance during titration was 15 cm H2O (interquartile range, 13 to 17; range, 8 to 19) in the entire sample of 40 patients. The primary outcome of postoperative atelectasis (available in 19 patients in each group) was 13.1 ± 5.3% and 9.5 ± 4.3% in the PEEP of 8 cm H2O and dynamic compliance-guided PEEP groups, respectively (intergroup difference, 3.7%; 95% CI, 0.5 to 6.8%; P = 0.025). Pao2/Fio2 at 1 h after pneumoperitoneum was higher in the dynamic compliance-guided PEEP group (397 vs. 337 mmHg; group difference, 60; 95% CI, 9 to 111; P = 0.017) but did not differ between the two groups 30 min after extubation (359 vs. 375 mmHg; group difference, -17; 95% CI, -53 to 21; P = 0.183). The incidence of postoperative pulmonary complications was 4 of 20 in both groups. CONCLUSIONS: Postoperative atelectasis was lower in patients undergoing laparoscopic bariatric surgery under dynamic compliance-guided PEEP versus PEEP of 8 cm H2O. Postoperative Pao2/Fio2 did not differ between the two groups.

Effects of an open lung extubation strategy compared with a conventional extubation strategy on postoperative pulmonary complications after general anesthesia: a single-centre pilot randomized controlled trial.

PURPOSE: Postoperative pulmonary complications (PPCs) are a common cause of morbidity. Postoperative atelectasis is thought to be a significant risk factor in their development. Recent imaging studies suggest that patients' extubation may result in similar postoperative atelectasis regardless of the intraoperative mechanical ventilation strategy used. In this pilot trial, we hypothesized that a study investigating the effects of an open lung extubation strategy compared with a conventional one on PPCs would be feasible. METHODS: We conducted a pilot, single-centre, double-blinded randomized controlled trial. Adult patients at moderate to high risk of PPCs and scheduled for elective surgery were eligible. Patients were randomized to an open lung extubation strategy (semirecumbent position, fraction of inspired oxygen [FIO2] 50%, pressure support ventilation, unchanged positive end-expiratory pressure) or to a conventional extubation strategy (dorsal decubitus position, FIO2 100%, manual bag ventilation). The primary feasibility outcome was global protocol adherence while the primary exploratory efficacy outcome was PPCs. RESULTS: We randomized 35 patients to the conventional extubation group and 34 to the open lung extubation group. We observed a global protocol adherence of 96% (95% confidence interval, 88 to 99), which was not different between groups. Eight PPCs occurred (two in the conventional extubation group vs six in the open lung extubation group). Less postoperative supplemental oxygen and better lung aeration were observed in the open lung extubation group. CONCLUSIONS: In this single-centre pilot trial, we observed excellent feasibility. A multicentre pilot trial comparing the effect of an open lung extubation strategy with that of a conventional extubation strategy on the occurrence of PPCs is feasible. STUDY REGISTRATION DATE: ClinicalTrials.gov (NCT04993001); registered 6 August 2021.

RéSUMé: OBJECTIF: Les complications pulmonaires postopératoires (CPP) sont une cause fréquente de morbidité. L'atélectasie postopératoire est considérée comme un facteur de risque important de CPP. Des études d'imagerie récentes suggèrent que l'extubation des patient·es peut entraîner une atélectasie postopératoire semblable, quelle que soit la stratégie de ventilation mécanique peropératoire utilisée. Dans cet essai pilote, nous avons émis l'hypothèse qu'une étude examinant les effets sur les CPP d'une stratégie d'extubation à poumon ouvert par rapport à une stratégie d'extubation conventionnelle serait réalisable. MéTHODE: Nous avons mené une étude randomisée contrôlée pilote, monocentrique et à double insu. Les patient·es adultes présentant un risque modéré à élevé de CPP et devant bénéficier d'une chirurgie non urgente étaient éligibles. Les patient·es ont été randomisé·es à une prise en charge par une stratégie d'extubation à poumon ouvert (position semi-couchée, fraction d'oxygène inspiré [FIO2] 50 %, ventilation par aide inspiratoire, pression positive télé-expiratoire inchangée) ou à une stratégie d'extubation conventionnelle (décubitus dorsal, FIO2 100 %, ventilation manuelle par masque). Le principal critère de faisabilité était l'adhésion au protocole global, tandis que les CPP constituaient le principal critère d'efficacité exploratoire. RéSULTATS: Nous avons randomisé 35 patient·es dans le groupe d'extubation conventionnelle et 34 dans le groupe d'extubation à poumon ouvert. Nous avons observé une adhésion globale au protocole de 96 % (intervalle de confiance à 95 %, 88 à 99), qui n'était pas différente entre les groupes. Huit CPP sont survenues (deux dans le groupe d'extubation conventionnelle vs six dans le groupe d'extubation à poumon ouvert). Nous avons observé des besoins moins importants en oxygène supplémentaire postopératoire et une meilleure aération pulmonaire dans le groupe extubé à poumon ouvert. CONCLUSION: Dans cet essai pilote monocentrique, nous avons observé une excellente faisabilité. Une étude pilote multicentrique comparant l'effet d'une stratégie d'extubation à poumon ouvert à celui d'une stratégie d'extubation conventionnelle sur la survenue de CPP est réalisable. DATE D'ENREGISTREMENT DE L'éTUDE: ClinicalTrials.gov (NCT04993001); enregistrée le 6 août 2021.

The effectiveness of postoperative rehabilitation interventions that include breathing exercises to prevent pulmonary atelectasis in lung cancer resection patients: a systematic review and meta-analysis.

BACKGROUND: The main aim of this systematic review was to determine the effectiveness of postoperative rehabilitation interventions that include breathing exercises as a component to prevent atelectasis in lung cancer resection patients. METHODS: In this review, we systematically and comprehensively searched the Cochrane Library, PubMed, EMBASE, and Web of Science in English and CNKI and Wanfang in Chinese from 2012 to 2022. The review included any randomized controlled trials focusing on the effectiveness of postoperative rehabilitation interventions that include breathing exercises to prevent pulmonary atelectasis in lung cancer patients. Participants who underwent anatomic pulmonary resection and received postoperative rehabilitation interventions that included breathing exercises as a component were included in this review. The study quality and risks of bias were measured with the GRADE and Cochrane Collaboration tools, and statistical analysis was performed utilizing RevMan 5.3 software. RESULTS: The incidence of atelectasis was significantly lower in the postoperative rehabilitation intervention group (OR = 0.35; 95% CI, 0.18 to 0.67; I2 = 0%; P = 0.67) than in the control group. The patients who underwent the postoperative rehabilitation program that included breathing exercises (intervention group) had higher forced vital capacity (FVC) scores (MD = 0.24; 95% CI, 0.07 to 0.41; I2 = 73%; P = 0.02), forced expiratory volume in one second (FEV1) scores (MD = 0.31; 95% CI, 0.03 to 0.60; I2 = 98%; P < 0.01) and FEV1/FVC ratios (MD = 9.09; 95% CI, 1.50 to 16.67; I2 = 94%; P < 0.01). CONCLUSION: Postoperative rehabilitation interventions that included breathing exercises decreased the incidence rate of atelectasis and improved lung function by increasing the FVC, FEV1, and FEV1/FVC ratio.

The effect of driving pressure-guided versus conventional mechanical ventilation strategy on pulmonary complications following on-pump cardiac surgery: A randomized clinical trial.

STUDY OBJECTIVE: Postoperative pulmonary complications occur frequently and are associated with worse postoperative outcomes in cardiac surgical patients. The advantage of driving pressure-guided ventilation strategy in decreasing pulmonary complications remains to be definitively established. We aimed to investigate the effect of intraoperative driving pressure-guided ventilation strategy compared with conventional lung-protective ventilation on pulmonary complications following on-pump cardiac surgery. DESIGN: Prospective, two-arm, randomized controlled trial. SETTING: The West China university hospital in Sichuan, China. PATIENTS: Adult patients who were scheduled for elective on-pump cardiac surgery were enrolled in the study. INTERVENTIONS: Patients undergoing on-pump cardiac surgery were randomized to receive driving pressure-guided ventilation strategy based on positive end-expiratory pressure (PEEP) titration or conventional lung-protective ventilation strategy with fixed 5 cmH2O of PEEP. MEASUREMENTS: The primary outcome of pulmonary complications (including acute respiratory distress syndrome, atelectasis, pneumonia, pleural effusion, and pneumothorax) within the first 7 postoperative days were prospectively identified. Secondary outcomes included pulmonary complication severity, ICU length of stay, and in-hospital and 30-day mortality. MAIN RESULTS: Between August 2020 and July 2021, we enrolled 694 eligible patients who were included in the final analysis. Postoperative pulmonary complications occurred in 140 (40.3%) patients in the driving pressure group and 142 (40.9%) in the conventional group (relative risk, 0.99; 95% confidence interval, 0.82-1.18; P = 0.877). Intention-to-treat analysis showed no significant difference between study groups regarding the incidence of primary outcome. The driving pressure group had less atelectasis than the conventional group (11.5% vs 17.0%; relative risk, 0.68; 95% confidence interval, 0.47-0.98; P = 0.039). Secondary outcomes did not differ between groups. CONCLUSION: Among patients who underwent on-pump cardiac surgery, the use of driving pressure-guided ventilation strategy did not reduce the risk of postoperative pulmonary complications when compared with conventional lung-protective ventilation strategy.

Postoperative pulmonary complications after sugammadex reversal of neuromuscular blockade: a systematic review and meta-analysis with trial sequential analysis.

BACKGROUND: Sugammadex has been reported to lower the incidence of postoperative residual neuromuscular blockade. Despite the advantages, until recently the effects of sugammadex on postoperative pulmonary complications (PPCs) were controversial. We conducted a systematic review and meta-analysis to determine whether reversal with sugammadex was associated with a lower risk of PPCs compared with neostigmine. METHODS: PubMed, Embase, and Cochrane Central Register of Controlled Trials were searched from inception to May 2022. Randomized controlled trials (RCTs) and observational studies comparing PPCs in patients receiving sugammadex or neostigmine as reversal agent at the end of surgery were included. The primary outcomes focused on PPCs including desaturation, pneumonia, atelectasis, noninvasive ventilation (NIV) and reintubation. Trial sequential analysis was performed on the primary outcomes to confirm whether firm evidence was reached. RESULTS: Meta-analysis of included studies showed that the rate of desaturation (43.2% vs 45.0%, RR = 0.82; 95% CI 0.63 to 1.05; p = 0.11) were comparable between the two groups. When looking at other primary outcomes, significantly lower risk of pneumonia (1.37% vs 2.45%, RR = 0.65; 95% CI 0.49 to 0.85; p = 0.002), atelectasis (24.6% vs 30.4%, RR = 0.64; 95% CI 0.42 to 0.98; p = 0.04), NIV (1.37% vs 2.33%, RR = 0.65; 95% CI 0.43 to 0.98; p = 0.04) and reintubation (0.99% vs 1.65%, RR = 0.62; 95% CI 0.43 to 0.91; p = 0.01) in the sugammadex group were detected compared with the neostigmine group. CONCLUSIONS: We concluded that sugammadex is more effective at reducing the incidence of PPCs including pneumonia, atelectasis, NIV and reintubation compared with neostigmine. Further evidence, preferably from RCTs, is required to confirm these findings.

Efficacy of prophylactic high-flow nasal cannula therapy for postoperative pulmonary complications after pediatric cardiac surgery: a prospective single-arm study.

PURPOSE: This study investigated the incidence of postoperative pulmonary complications (PPC) when high-flow nasal cannula therapy (HFNC) is used prophylactically after pediatric cardiac surgery, and evaluated its efficacy. METHODS: This was a single-arm prospective interventional study that was conducted in a tertiary teaching hospital with eight beds in the pediatric cardiac ICU after approval by the Ethics Committee. One-hundred children under the age of 48 months who were scheduled for cardiac surgery for congenital heart disease were recruited. HFNC was used for 24 h after extubation at a 2 L/kg/min flow rate. The primary outcome was the incidence of PPC within 48 h after extubation. PPC was defined as atelectasis and acute respiratory failure meeting certain criteria. We considered prophylactic HFNC as effective if the prevalence of PPC was < 10%, based on previous reports of reintubation rates of 6%-9% after pediatric cardiac surgery. RESULTS: A total of 91 patients were finally included in the analysis. The incidence of PPC within 48 h after extubation was 18.7%, whereas atelectasis was observed in 13.2%, and acute respiratory failure in 8.8%. Reintubation rate within 48 h after extubation was 0%. CONCLUSIONS: We found the incidence of PPC with prophylactic HFNC after planned extubation after pediatric cardiac surgery. However, the incidence was > 10%; therefore, we could not demonstrate its efficacy in this single-arm study. Further studies are needed to investigate whether the HFNC could be adapted as first-line oxygen therapy after pediatric cardiac surgery.