Hyperoxemia post thoracic surgery – Does it matter?

Background Visceral adipose tissue (VAT) is associated with postoperative complications following surgery for cancers such as pancreatic and colorectal. We report results of VAT area and its association with acute adverse outcomes in patients undergoing esophagectomy for cancer. Methods We performed a retrospective analysis of patients who underwent esophagectomy for cancer at a single institution. Pre-surgical computed tomography DICOM files underwent body segmentation at L3 using a semi-automated method. Muscle and VAT components were measured as cross-sectional area. The relationship between VAT and muscle areas and postoperative outcomes (categorized as pulmonary, cardiovascular (CV), or other) were analyzed. Results We included 157 patients with a median age of 63.2 years. Median BMI was 28.4 and most received neoadjuvant therapy (108; 69%). Median hospital stay was 9 days. 30-day mortality was 3.8%. 49 patients (31%) experienced at least one CV complication. 29 patients (18%) experienced at least one pulmonary complications. VAT and low density muscle (indicating fatty infiltration) areas were related to BMI, normal density muscle area was not. Patients in the highest quartile of VAT area experienced an increased incidence of postoperative pulmonary (p = 0.039) and CV (p = 0.012) complications (Figure). We identified no relationship between muscle area and acute outcomes. Conclusion In patients undergoing esophagectomy for cancer, high visceral adipose tissue area on CT was predictive of an increased incidence of postoperative pulmonary and cardiovascular complications. This association may be related to the endocrine effects of adipocytes and their activation of a proinflammatory state that increases with expanding fat volume. Further exploration of this relationship is needed as is identification of modifiable pharmacologic targets to minimize morbidity following esophagectomy.

Lung cancer is the primary cause of cancer-related death in the United States and many other countries, with 5-year survival rates of approximately 15%.1 Despite the grim overall prognosis, there are better outcomes among patients with stage I or II non–small cell lung cancer who undergo a complete anatomic resection.2 Unfortunately, approximately 90% of patients with lung cancer are smokers, and a substantial percentage will have chronic obstructive pulmonary disease.1,3 Moreover, many of these patients will also have significant cardiovascular disease and other medical conditions that increase overall perioperative risk. Despite improvements in pre-, intra-, and postoperative care, the mortality and morbidity associated with pulmonary resection remain high. The American College of Chest Physicians (ACCP) guidelines recommend surgical mortality risk to be <4% for lobectomy and <9% for a pneumonectomy4; the British Thoracic Society guidelines offer similar expectations.5 A review of a large European lung cancer registry revealed 30-day postoperative mortality to be 3.1% after lung resection.6 Among the elderly (age >70 years), mortality rates are reported to be even higher: 14% for pneumonectomy and 4% to 7% for lobectomy.5 These rates, however, seem to have more to do with comorbid conditions than age alone as a risk factor. The risk of pulmonary complications, including pneumonia, acute respiratory distress syndrome, prolonged ventilator support, atelectasis requiring bronchoscopy, and reintubation, is also a serious concern. A recent review of almost 7900 patients in The Society of Thoracic Surgeons' General Thoracic Surgery Database revealed an overall pulmonary complication rate of 13%.7 The challenge confronting the multidisciplinary teams of pulmonologists, oncologists, thoracic surgeons, anesthesiologists, and critical care intensivists caring for these patients is to identify those patients at greatest risk for perioperative cardiopulmonary complications. Fortunately, there are several guidelines for preoperative evaluation, each with a helpful algorithm describing a step-wise investigation of a patient's suitability for lung resection.4,5,8,9 The algorithms usually begin with a thorough cardiac assessment, followed by basic spirometry. Depending on these initial results, the guidelines make a variety of recommendations with regard to additional testing of the diffusing capacity of the lung for carbon monoxide (DLCO) and different methods of cardiopulmonary exercise testing. Yet, despite the presence of these guidelines, questions remain about the strength of the evidence backing them.3,10 Without question, there is still controversy regarding the specific steps in the proposed algorithms. What matters most in predicting bad outcomes: spirometry or DLCO, or a combination of the two? Should patients be stratified according to spirometric results reported as absolute volumes or percent predicted? What is the best method of determining predicted postoperative lung function: perfusion or anatomic methods? Do the guidelines place too little emphasis on exercise testing? Should we encourage more use of cardiopulmonary exercise testing, as some authors have suggested?11–13 A recent review expressed concern that there was not better “harmonization” among the guidelines.3 Perhaps we can attribute the lack of consensus as an indication that we need further examination of the specific tests and their ability to predict postoperative complications. To that end, in this issue of Anesthesia & Analgesia, Amar et al.14 investigated whether predicted postoperative DLCO (DLCOppo) or forced expired volume in 1 second (FEV1) is better able to predict pulmonary complications after thoracic surgery. Their study was a retrospective review of 956 patients from a prospective database undergoing resection for primary lung cancer between 1992 and 2003 at a single institution. Approximately 20% underwent preoperative chemotherapy. Pulmonary complications, defined as respiratory failure requiring intensive care unit admission or intubation, pneumonia, atelectasis requiring bronchoscopy, pulmonary embolism, and need for supplemental oxygen at hospital discharge, occurred in approximately 13% of patients. The authors found significant univariate associations between pulmonary complications and preoperative serum albumin, preoperative chemotherapy, and both DLCO and DLCOppo. Only DLCOppo and preoperative chemotherapy were independent risk factors for pulmonary complications. Interestingly, FEV1, a major part of the ACCP, British Thoracic Society, and European Respiratory Society/European Society of Thoracic Surgeons guidelines, was not a predictor of postoperative pulmonary complications. In addition, the study found that patients developing pulmonary complications had a longer length of hospital stay and higher 30-day mortality. The authors also developed a simple scoring system to predict postoperative pulmonary complications. These findings, although important, are not without precedent in the literature. The potential for increased risk for pulmonary complications after induction chemotherapy has been reported previously, largely as a result of its negative effect on diffusing capacity.15 The ACCP guidelines also discuss data that suggest that preinduction chemotherapy may increase the risk of pulmonary complications.4 The usefulness of DLCO/DLCOppo versus FEV1 in preoperative evaluation deserves further discussion. Despite the prominence of FEV1 and predicted postoperative FEV1 in the above-mentioned algorithms, the guidelines caution against an overreliance on these values alone. A recent meta-analysis also raised doubts about the value of FEV1 as an independent predictor of postoperative pulmonary complications.13 The role of DLCO as a predictor of postoperative complications has been studied since the 1980s, when Ferguson et al.16 reported it to be a strong independent predictor of postoperative mortality and pulmonary complications. Since that time, several additional investigations7,17–21 have demonstrated the utility of DLCO and/or DLCOppo in predicting adverse outcomes in patients undergoing lung resection. It is especially notable that several of these studies demonstrated the importance of DLCO for risk stratification regardless of spirometric findings. How should the anesthesiologist view this study in the context of the current major guidelines and literature? First, it seems increasingly clear that DLCO measurements and calculation of DLCOppo should be included with spirometry as the initial tests for patients before lung resection. Interestingly, a 2009 survey of members of the European Respiratory Society and European Society of Thoracic Surgeons revealed that only one-third obtained DLCO testing in all patients before lung resection.22 Is this due to a lack of appreciation of its utility, or is it a result of limited access to pulmonary function laboratories capable of performing the test? Second, we applaud the authors' efforts to develop a practical scoring system to predict pulmonary complications. Because many patients undergoing lung resection have FEV1 and DLCO values <80% predicted, it is helpful to have a simple scoring system to categorize patients into low-, intermediate-, and high-risk groups. There are other scoring systems or prognostic models but they may not be practical enough to be of use to the busy clinician.22,23 Furthermore, these scoring systems for risk need validation in prospective studies. Third, some type of cardiopulmonary testing needs further consideration as part of the baseline evaluation of all lung resection candidates. Amar et al. did not consider exercise testing in their study, and this is a limitation given its important role in the determination of suitability for an operation. We are interested in recent investigations that demonstrate improved risk stratification using both formal cardiopulmonary exercise testing12 and a less expensive, more readily available stair-climbing test.11 This is an important contribution to a growing body of research. As anesthesiologists and critical care physicians involved in the care of complicated patients undergoing lung resection, we need evidence-based algorithms and scoring systems to guide our evaluation.

Mechanical power (MP), the rate of mechanical energy (ME) delivery, is a recently introduced unifying ventilator parameter consisting of tidal volume, airway pressures, and respiratory rates, which predicts pulmonary complications in several clinical contexts. However, ME has not been previously studied in the perioperative context, and neither parameter has been studied in the context of thoracic surgery utilizing one-lung ventilation. The relationships between ME variables and postoperative pulmonary complications were evaluated in this post hoc analysis of data from a multicenter randomized clinical trial of lung resection surgery conducted between 2020 and 2021 (n = 1,170). Time-weighted average MP and ME (the area under the MP time curve) were obtained for individual patients. The primary analysis was the association of time-weighted average MP and ME with pulmonary complications within 7 postoperative days. Multivariable logistic regression was performed to examine the relationships between energy variables and the primary outcome. In 1,055 patients analyzed, pulmonary complications occurred in 41% (431 of 1,055). The median (interquartile ranges) ME and time-weighted average MP in patients who developed postoperative pulmonary complications versus those who did not were 1,146 (811 to 1,530) J versus 924 (730 to 1,240) J (P < 0.001), and 6.9 (5.5 to 8.7) J/min versus 6.7 (5.2 to 8.5) J/min (P = 0.091), respectively. ME was independently associated with postoperative pulmonary complications (ORadjusted, 1.44 [95% CI, 1.16 to 1.80]; P = 0.001). However, the association between time-weighted average MP and postoperative pulmonary complications was time-dependent, and time-weighted average MP was significantly associated with postoperative pulmonary complications in cases utilizing longer periods of mechanical ventilation (210 min or greater; ORadjusted, 1.46 [95% CI, 1.11 to 1.93]; P = 0.007). Normalization of ME and time-weighted average MP either to predicted body weight or to respiratory system compliance did not alter these associations. ME and, in cases requiring longer periods of mechanical ventilation, MP were independently associated with postoperative pulmonary complications in thoracic surgery.

Association of Complications With Blood Transfusions in Pediatric Cardiac Surgery Patients

Lung resection surgery carries significant risks of postoperative pulmonary complications (PPC). Cardiopulmonary exercise testing (CPET) is performed to predict risk of PPC in patients with severely reduced predicted postoperative forced expiratory volume in one second (FEV1) and diffusion of carbon monoxide (DLCO). Recently, resting end-tidal partial pressure of carbon dioxide (PETCO2) has been shown as a good predictor for increased risk of PPC. However, breath-breath breathing pattern significantly affects PETCO2. Resting physiologic dead space (VD), and physiologic dead space to tidal volume ratio (VD/VT), may be a better predictor of PPC than PETCO2. The objective of this study was to prospectively determine the utility of resting measurements of VD and VD/VT in predicting PPC in patients who underwent robotic-assisted lung resection for suspected or biopsy-proven lung malignancy. Thirty-five consecutive patients were included in the study. Patients underwent preoperative pulmonary function testing, symptom-limited CPET, and a 6-min walk test. In the first 2 min prior to the exercise portion of the CPET, we obtained resting VT, minute ventilation (E), VD (less instrument dead space), VD/VT, PETCO2, and arterial blood gases. PPC within 90 days were recorded. Fourteen (40%) patients had one or more PPC. Patients with PPC had significantly elevated resting VD compared to those without (0.318 ± 0.028 L vs. 0.230 ± 0.017 L (± SE), p < 0.006), and a trend toward increased VD/VT (0.35 ± 0.02 vs. 0.31 ± 0.02, p = 0.051). Area under the receiver operating characteristic (ROC) for VD was 0.81 (p < 0.002), VD/VT was 0.68 (p = 0.077), and PETCO2 was 0.52 (p = 0.840). Peak O2, E/ CO2 slope, pulmonary function tests, 6-min walk distance and arterial blood gases were similar between the two groups. Intensive care unit and total hospital length of stay was significantly longer in those with PPC. In conclusion, preoperative resting VD was significantly elevated in patients with PPC. The observed increase in resting VD may be a potentially useful predictor of PPC in patients undergoing robotic-assisted lung resection surgery for suspected or biopsy-proven lung malignancy. A large prospective study is needed for confirmation.

Response to: ‘Postoperative pulmonary complications, pulmonary and systemic inflammatory responses after lung resection surgery with prolonged one-lung ventilation. Randomised controlled trial comparing intravenous and inhalational anaesthesia’

BackgroundFew studies have investigated the relationship between sarcopenia and postoperative pulmonary complications (PPCs) after gastric cancer surgery. This study aimed to explore the impact of sarcopenia on PPCs in patients who had undergone gastric cancer surgery.MethodsWe included patients who underwent a transabdominal radical gastrectomy between June 2016 and October 2020. Patients were divided into two groups according to the median prevalence rate of lumbar triplane skeletal muscle index (L3 SMI): sarcopenia group (≤37.5% percentile in male and female group) and non-sarcopenia group (>37.5% percentile in male and female group). Baseline characteristics, intraoperative and postoperative conditions, pulmonary complications, and overall complications were compared between the two groups. The primary outcome was the incidence of PPCs. The secondary outcomes were overall postoperative complications and length of stay (LOS).ResultsAmong the 143 patients included, 50 had sarcopenia and 93 had not. Compared to the non-sarcopenia group, the sarcopenia group had a higher the incidence of PPCs (22.0% vs. 8.6%, P = 0.024). The incidence of overall postoperative complications in the sarcopenia group was higher than that in the non-sarcopenia group (36.00% vs. 20.43%, P = 0.043). There was no significant difference in the LOS between the two groups.ConclusionsOur research indicates that sarcopenia, preoperative comorbidities, and longer duration of intraoperative oxygen saturation <95% were risk factors for PPCs. Sarcopenia is an independent risk factor for postoperative complications. Given that our results provided a correlation rather than causation, future prospective randomized trials are needed to confirm the relationship between sarcopenia and prognosis.

Cardiovascular complications after major surgery are associated with increases in morbidity and mortality. There is confusion over definitions of cardiac injury or complications, and variability in the assessment and management of patients. This international prospective cohort study aimed to define the incidence and timing of these complications and to investigate their impact on 30-day all-cause mortality. We performed a prospective, international cohort study between January 2022 and May 2022. Data were collected on consecutive patients undergoing major abdominal surgery in 446 hospitals from 28 countries across Europe. The primary outcome measure was cardiovascular complications as defined by the Standardised Endpoints for Perioperative Medicine-Core Outcome Measures for Perioperative and Anaesthetic Care initiative up to 30 days after surgery. The secondary outcome was 30-day postoperative mortality. This study included 24,203 patients, of whom 611 (2.5%) developed cardiovascular complications. In total, 458 (1.9%) patients died within 30 days of surgery, of which 123 (26.9%) deaths were judged to be cardiac-related. Mortality rates were higher in patients who developed postoperative cardiovascular complications than in those who did not (19.8% vs. 1.4%), which persisted after risk adjustment (hazard ratio (95%CI) 4.15 (3.14-5.48)). We estimated an absolute risk reduction (95%CI) of 0.4 (0.3-0.5) in mortality in the absence of all cardiovascular complications. This would confer a relative risk reduction in mortality of 21.1% if all cardiovascular complications were prevented. Postoperative cardiovascular complications are relatively common and occur early after major abdominal surgery. However, over 1 in 5 postoperative deaths were attributable to these complications, highlighting an important area for future randomised trials.

Background: Morbid obesity is associated with variable degrees of pulmonary dysfunction that may predispose to postoperative complications. This study aimed to identify high risk patients to have pulmonary dysfunction before bariatric surgery in terms of age, sex, and body mass index (BMI) and the impact of pulmonary dysfunction on postoperative pulmonary complications. Methods: Prospective database of patients with morbid obesity who underwent bariatric surgery was reviewed. Data on patients' demographics, parameters of pulmonary function tests, and postoperative pulmonary complications were collected. The correlation between patients' age, sex and BMI, and pulmonary function was investigated using Pearson's correlation coefficient test. Results: Ninety-seven patients (82 female) with morbid obesity were included in the study. Twenty-eight (28.9%) patients had pulmonary dysfunction. Patients >40 years had higher odds of pulmonary dysfunction than patients ≤40 years (odds ratio [OR]: 2.54, P = .05). Male patients had significantly higher odds of pulmonary dysfunction than female patients (OR: 2.5, P = .03). Patients with BMI >50 had significantly higher odds of pulmonary dysfunction than patients with BMI <50 (OR: 4.9, P = .002). Patients with pulmonary dysfunction had significantly higher odds of developing pulmonary complications than patients with normal spirometry (OR: 9.13, P = .009). Conclusion: Around 30% of patients undergoing bariatric surgery had pulmonary dysfunction. Pulmonary dysfunction in preoperative spirometry was able to predict postoperative pulmonary complications. Men, patients older than 40 years, and superobese individuals had higher odds of having pulmonary dysfunction and are at higher risk to develop pulmonary complications after bariatric surgery.

RATIONALE: Guidelines from the American College of Chest Physicians (2013) and the European Respiratory Society/European Society of Thoracic Surgeons (2009) recommend using VO2peak from cardiopulmonary exercise testing (CPET) for risk stratification of postoperative pulmonary complications (PPCs). However, other CPET parameters and specific aspects of lung resection procedures remain unexplored, yet they may significantly influence surgical outcomes. METHODS: This study included 94 patients who underwent preoperative CPET before lung resection surgery at Pham Ngoc Thach Hospital, Ho Chi Minh City, Vietnam, from January 2021 to August 2024. Eligibility required patients over 18 years old, excluding those who declined or ultimately did not undergo lung resection. Surgery indications included atelectasis due to post-tuberculosis bronchial stenosis (60%), lung tumors/cancer (28%), and other conditions like lung aspergilloma, bronchiectasis, lung abscess, and cysts. Data collection included spirometry, DLCO, CPET (conducted using a ramp protocol on a cycle ergometer), PaCO2, albumin, intraoperative details, and PPCs. RESULTS: Of the 94 patients, the male-to-female ratio was approximately 1:2.5. The mean VO2peak was 21.4 mL/kg/min, reaching 67% predicted. Ventilatory threshold 1 (VT1) was identified in 89 cases, averaging 14.7 mL/kg/min. PPCs occurred in 30 out of 94 cases (32%). Analysis revealed that VO2peak was weakly inversely associated with PPCs (r = -0.240; p = 0.020). Heart rate recovery showed a moderate inverse correlation with hospital stay duration (r = -0.321; p = 0.002). VE/VCO2 at VT1 (r = 0.374; p &amp;lt; 0.001) and surgical duration (r = 0.326; p = 0.001) were moderately positively correlated with hospital stay duration. Bronchoplastic surgery showed a moderate positive correlation with PPCs (r = 0.477; p &amp;lt; 0.001), a moderate inverse correlation with postoperative oxygen duration (r = -0.309; p = 0.002), and ICU stay duration (r = -0.482; p &amp;lt; 0.001). KCO (HGB) Z-score showed a moderate positive correlation with PPCs (r = 0.401; p = 0.010) and a moderate inverse correlation with postoperative ICU stay (r = -0.365; p = 0.021). Logistic regression incorporating VO2peak, FEV1, KCO (HGB), and bronchoplastic surgery yielded 90% accuracy in predicting PPCs, with an ROC-AUC of 0.943, sensitivity of 90%, specificity of 90%, PPV of 75%, and NPV of 96%. CONCLUSION: The study identifies a broader range of CPET indices, bronchoplastic surgery, and KCO as significant predictors of outcomes following lung resection. These findings suggest that considering multiple CPET parameters in addition to VO2peak may enhance postoperative respiratory outcome predictions.

Ideal timing of postoperative β-blockers is unclear. We hypothesized that patients who do not receive β-blockers immediately after cardiac surgery would have increased in-hospital mortality (primary outcome) and postoperative hemodynamic, pulmonary, neurologic, or respiratory complications (secondary outcomes). We performed a retrospective cohort study evaluating patients who underwent cardiac surgery at our institution from January 1, 2013 to September 30, 2017. We compared outcomes between patients who received β-blockers by postoperative day (POD) 5 with outcomes in patients who did not receive β-blockers at any time or received them after POD 5. Inverse probability of treatment weighting was used to minimize confounding. Univariate logistic regression analyses were performed on the weighted sets using absent or delayed β-blockers as the independent variable and each outcome as dependent variables in separate analyses. A secondary analysis was performed in patients prescribed preoperative β-blockers. E-values were calculated for significant outcomes. All results were confounder adjusted. Among patients presenting for cardiac surgery, not receiving β-blockers by POD 5 or at any time was not associated with the primary outcome in-hospital mortality, estimated odds ratio (OR; 99.5% confidence interval [CI]) of 1.6 (0.49-5.1), P = .28. Not receiving β-blockers by POD 5 or at any time was associated with postoperative atrial fibrillation, estimated OR (99.5% CI) of 1.5 (1.1-2.1), P < .001, and pulmonary complications, estimated OR (99.5% CI) of 3.0 (1.8-5.2), P < .001. E-values were 2.4 for postoperative atrial fibrillation and 5.6 for pulmonary complications. Among patients presenting for cardiac surgery taking preoperative β-blockers, not receiving β-blockers by POD 5 or at any time was not associated with the primary outcome mortality, with estimated OR (99.5% CI) of 1.3 (0.43-4.1), P = .63. In this subset, not receiving β-blockers by POD 5 or at any time was associated with increased adjusted ORs of postoperative atrial fibrillation (OR = 1.6; 99.5% CI, 1.1-2.4; P < .001) and postoperative pulmonary complications (OR = 2.8; 99.5% CI, 1.6-5.2; P < .001). Here, e-values were 2.7 for postoperative atrial fibrillation and 5.1 for pulmonary complications. For the sensitivity analyses for secondary outcomes, exposure and outcome periods overlap. Outcomes may have occurred before or after postoperative β-blocker administration. Among patients who undergo cardiac surgery, not receiving postoperative β-blockers within the first 5 days after cardiac surgery or at any time is not associated with in-hospital mortality and is associated with, but may not necessarily cause, postoperative atrial fibrillation and pulmonary complications.

HighlightsWhat are the main findings?Preoperative six-minute walking distance (6MWD) of ≤450 m was independently associated with a 5.6-fold higher risk of 30-day postoperative pulmonary complications after VATS lobectomy for non-small-cell lung cancer.In the logistic regression analysis focusing on pulmonary complications, the length of hospital stay was further identified as a significant factor.What are the implications of the main findings?A simple, low-cost six-minute walk test (6MWT) can serve as a practical preoperative risk stratification tool, complementing routine spirometry to identify high-risk patients.Patients with a 6MWD of ≤450 m may benefit from targeted prehabilitation or intensified perioperative management to reduce postoperative morbidity.Introduction: Minimally invasive video-assisted thoracic surgery (VATS) for lung cancer has become a widely used approach. However, postoperative pulmonary complications (PCs) such as pneumonia, atelectasis, and lung fistula remain significant challenges, particularly in older adult patients with multiple comorbidities. The 6-minute walk test (6MWT) has been suggested as a predictor of postoperative outcomes in various surgical settings, but its relationship with postoperative complications following VATS lobectomy for lung cancer has not been thoroughly explored. The aim of this study was to determine if preoperative 6MWD predicted the occurrence of 30-day PCs among patients undergoing VATS lobectomy for non-small-cell lung cancer. Methods: This retrospective study examined 66 patients who underwent VATS lobectomy for lung cancer. Participants were categorized into two groups: those with postoperative pulmonary complications (n = 11) and those without (n = 55). The research period was from January to September 2022. The preoperative 6MWT distance, along with other clinical and demographic factors, was assessed to determine its predictive value for postoperative complications. Multivariate logistic regression analysis was performed to identify significant predictors. Results: The study found that preoperative 6MWT ≤ 450 m was a significant predictor of postoperative pulmonary complications (odds ratio: 5.674, 95% CI: 1.206–26.684, p = 0.028). Conclusions: The preoperative 6MWT distance is a useful predictor of postoperative pulmonary complications in patients undergoing VATS lobectomy for lung cancer. Patients with a 6MWT ≤ 450 m may be at higher risk for complications such as pneumonia, atelectasis, and lung fistula. Incorporating preoperative 6MWT as a risk stratification tool could help guide clinical decisions and rehabilitation efforts to improve postoperative outcomes in this patient population.

Few studies have investigated the changes in diaphragmatic function and their association with postoperative pulmonary complications (PPCs) in paediatric patients after lung resection. This study aimed to evaluate diaphragmatic function using ultrasound after lung resection and its influence on PCCs in children. Prospective observational study. A tertiary children's hospital. Children aged 6 years or less who were scheduled for video-assisted thoracoscopic lung resection. Ultrasonographic measurements of diaphragmatic excursion (DE) and thickening fraction (TF) were performed for three epochs: before anaesthesia induction (T0), 1 h postoperatively (T1) and 24 h postoperatively (T2). The thickening fraction is calculated from the thickness of the diaphragm at end expiration and end inspiration at each time point. DE T1 /DE T0 , DE T2 /DE T0 , TF T1 /TF T0 and TF T2 /TF T0 (%) were calculated. The incidence of PCCs was also determined. The primary outcomes were changes in diaphragmatic excursion and thickening fraction over time, from T0 to T2. The secondary outcomes were the association between ultrasound parameters of diaphragm function and the occurrence of early PPCs within 3 days. Data from 74 children were analysed. On the operated side, both diaphragmatic excursion and thickening fraction decreased at T1 and recovered slightly at T2, and were significantly lower than the T0 values. Children with PPCs had significantly lower DE T2 /DE T0 and TF T2 /TF T0 scores on the operated side than those without PPCs. According to the receiver operating characteristic analysis, the DE T2 /DE T0 (< 61.1%) on the operated side was associated with PPCs with an area under the curve of 0.764. Peri-operative diaphragmatic function assessed by ultrasonography changed after lung resection in children. The diaphragmatic excursion and thickening fraction decreased postoperatively, and a prolonged decrease in diaphragmatic excursion was associated with pulmonary complications after lung surgery in children. ClinicalTrials.gov, NCT04400370.

BackgroundHip fracture surgery on elderly patients is associated with a high incidence of morbidity and mortality. The aim of this study is to identify the risk factors related to the postoperative mortality and complications following hip fracture surgery on elderly patients.MethodsIn this retrospective study, the medical records of elderly patients (aged 65 years or older) who underwent hip fracture surgery from January 2011 to June 2014 were reviewed. A total of 464 patients were involved. Demographic data of the patients, American Society of Anesthesiologists physical status, preoperative comorbidities, type and duration of anesthesia and type of surgery were collected. Factors related to postoperative mortality and complications; as well as to intensive care unit admission were analyzed using logistic regression.ResultsThe incidence of postoperative mortality, cardiovascular complications, respiratory complications and intensive care unit (ICU) admission were 1.7, 4.7, 19.6 and 7.1%, respectively. Postoperative mortality was associated with preoperative respiratory comorbidities, postoperative cardiovascular complications (P < 0.05). Postoperative cardiovascular complications were related to frequent intraoperative hypotension (P <0.05). Postoperative respiratory complications were related to age, preoperative renal failure, neurological comorbidities, and bedridden state (P < 0.05). ICU admission was associated with the time from injury to operation, preoperative neurological comorbidities and frequent intraoperative hypotension (P < 0.05).ConclusionsAdequate treatment of respiratory comorbidities and prevention of cardiovascular complications might be the critical factors in reducing postoperative mortality in elderly patients undergoing hip fracture surgery.

Objective To probe the correlation between preoperative pulmonary dysfunction and postoperative pulmonary complications in patients of orthotopic liver transplantation. Methods From August 2008 to June 2009, 71 orthotopic liver transplantation patients were studied. Preoperative pulmonary function and its relationship with postoperative pulmonary complications were analyzed.Results Preoperatively 65 out of 71 patients had abnormal lung functions, suffering from pulmonary diffusing capacity reduction (65 cases, 91.5% ), followed by reduction of restrictive ventilation function (30 cases, 42. 2% ), small airway function reduction ( 28 cases, 39.4% ), and obstructive ventilatory function reduction (21 cases, 29. 6% ). The incidence of postoperative pulmonary complications was 56. 3% including: pulmonary atelectasis, pneumonia, acute respiratory failure. The incidence of posttransplantation pulmonary complications in patients with pulmonary restrictive or obstructive ventilation function reduction was higher than in normal group (x2 = 6.703, P= 0.010; x2 = 4.768, P = 0.029), and there was significant difference in pulmonary complication rate between groups of moderate and severe diffusing capacity reduction and mild reduction and normal range (x2 = 8.478, P = 0.004 ).Conclusions Preoperative pulmonary function abnormality in patients before liver transplantation such as pulmonary ventilatory function reduction (VCmax ＜ 80% or FEV1.0 ＜ 80% ) and moderate to severe pulmonary diffusing capacity reduction (TLCOSB ＜ 60% ) predicts higher incidence of postoperative pulmonary complications. Key words: Liver transplantation; Postoperative complications; Pulmonary function