Prediction of postoperative pulmonary complications in a population-based surgical cohort. Anesthesiology. 2010;113:1338-1350. [PMID: 21045639 DOI: 10.1097/aln.0b013e3181fc6e0a]

Electrical Impedance Tomography-based Ventilation Patterns in Patients after Major Surgery

Rationale: General anesthesia and mechanical ventilation have negative impacts on the respiratory system, causing heterogeneous distribution of lung aeration, but little is known about the ventilation patterns of postoperative patients and their association with clinical outcomes. Objectives: To clarify the phenotypes of ventilation patterns along a gravitational direction after surgery by using electrical impedance tomography (EIT) and to evaluate their association with postoperative pulmonary complications (PPCs) and other relevant clinical outcomes. Methods: Adult postoperative patients at high risk for PPCs, receiving mechanical ventilation on ICU admission (N = 128), were prospectively enrolled between November 18, 2021 and July 18, 2022. PPCs were prospectively scored until hospital discharge, and their association with phenotypes of ventilation patterns was studied. The secondary outcomes were the times to wean from mechanical ventilation and oxygen use and the length of ICU stay. Measurements and Main Results: Three phenotypes of ventilation patterns were revealed by EIT: phenotype 1 (32% [n = 41], a predominance of ventral ventilation), phenotype 2 (41% [n = 52], homogeneous ventilation), and phenotype 3 (27% [n = 35], a predominance of dorsal ventilation). The median PPC score was higher in phenotype 1 and phenotype 3 than in phenotype 2. The median time to wean from mechanical ventilation was longer in phenotype 1 versus phenotype 2. The median duration of ICU stay was longer in phenotype 1 versus phenotype 2. The median time to wean from oxygen use was longer in phenotype 1 and phenotype 3 than in phenotype 2. Conclusions: Inhomogeneous ventilation patterns revealed by EIT on ICU admission were associated with PPCs, delayed weaning from mechanical ventilation and oxygen use, and a longer ICU stay.

Multicentre validation of a machine learning model for predicting respiratory failure after noncardiac surgery

BACKGROUND

Postoperative respiratory failure is a serious complication that could benefit from early accurate identification of high-risk patients. We developed and validated a machine learning model to predict postoperative respiratory failure, defined as prolonged (>48 h) mechanical ventilation or reintubation after surgery.

METHODS

Easily extractable electronic health record (EHR) variables that do not require subjective assessment by clinicians were used. From EHR data of 307,333 noncardiac surgical cases, the model, trained with a gradient boosting algorithm, utilised a derivation cohort of 99,025 cases from Seoul National University Hospital (2013-9). External validation was performed using three separate cohorts A-C from different hospitals comprising 208,308 cases. Model performance was assessed by area under the receiver operating characteristic (AUROC) curve and area under the precision-recall curve (AUPRC), a measure of sensitivity and precision at different thresholds.

RESULTS

The model included eight variables: serum albumin, age, duration of anaesthesia, serum glucose, prothrombin time, serum creatinine, white blood cell count, and body mass index. Internally, the model achieved an AUROC of 0.912 (95% confidence interval [CI], 0.908-0.915) and AUPRC of 0.113. In external validation cohorts A, B, and C, the model achieved AUROCs of 0.879 (95% CI, 0.876-0.882), 0.872 (95% CI, 0.870-0.874), and 0.931 (95% CI, 0.925-0.936), and AUPRCs of 0.029, 0.083, and 0.124, respectively.

CONCLUSIONS

Utilising just eight easily extractable variables, this machine learning model demonstrated excellent discrimination in both internal and external validation for predicting postoperative respiratory failure. The model enables personalised risk stratification and facilitates data-driven clinical decision-making.

Comparison of lung aeration loss in open abdominal oncologic surgeries after ventilation with electrical impedance tomography-guided PEEP versus conventional PEEP: a pilot feasibility study

BACKGROUND

Existing literature lacks high-quality evidence regarding the ideal intraoperative positive end-expiratory pressure (PEEP) to minimize postoperative pulmonary complications (PPCs). We hypothesized that applying individualized PEEP derived from electrical impedance tomography would reduce the severity of postoperative lung aeration loss, deterioration in oxygenation, and PPC incidence.

METHODS

A pilot feasibility study was conducted on 36 patients who underwent open abdominal oncologic surgery. The patients were randomized to receive individualized PEEP or conventional PEEP at 4 cmH2O. The primary outcome was the impact of individualized PEEP on changes in the modified lung ultrasound score (MLUS) derived from preoperative and postoperative lung ultrasonography. A higher MLUS indicated greater lung aeration loss. The secondary outcomes were the PaO2/FiO2 ratio and PPC incidence.

RESULTS

A significant increase in the postoperative MLUS (12.0 ± 3.6 vs 7.9 ± 2.1, P < 0.001) and a significant difference between the postoperative and preoperative MLUS values (7.0 ± 3.3 vs 3.0 ± 1.6, P < 0.001) were found in the conventional PEEP group, indicating increased lung aeration loss. In the conventional PEEP group, the intraoperative PaO2/FiO2 ratios were significantly lower but not the postoperative ratios. The PPC incidence was not significantly different between the groups. Post-hoc analysis showed the increase in lung aeration loss and deterioration of intraoperative oxygenation correlated with the deviation from the individualized PEEP.

CONCLUSIONS

Individualized PEEP appears to protect against lung aeration loss and intraoperative oxygenation deterioration. The advantage was greater in patients whose individualized PEEP deviated more from the conventional PEEP.

Incorporating preoperative frailty to assist in early prediction of postoperative pneumonia in elderly patients with hip fractures: an externally validated online interpretable machine learning model

BACKGROUND

This study aims to implement a validated prediction model and application medium for postoperative pneumonia (POP) in elderly patients with hip fractures in order to facilitate individualized intervention by clinicians.

METHODS

Employing clinical data from elderly patients with hip fractures, we derived and externally validated machine learning models for predicting POP. Model derivation utilized a registry from Nanjing First Hospital, and external validation was performed using data from patients at the Fourth Affiliated Hospital of Nanjing Medical University. The derivation cohort was divided into the training set and the testing set. The least absolute shrinkage and selection operator (LASSO) and multivariable logistic regression were used for feature screening. We compared the performance of models to select the optimized model and introduced SHapley Additive exPlanations (SHAP) to interpret the model.

RESULTS

The derivation and validation cohorts comprised 498 and 124 patients, with 14.3% and 10.5% POP rates, respectively. Among these models, Categorical boosting (Catboost) demonstrated superior discrimination ability. AUROC was 0.895 (95%CI: 0.841-0.949) and 0.835 (95%CI: 0.740-0.930) on the training and testing sets, respectively. At external validation, the AUROC amounted to 0.894 (95% CI: 0.821-0.966). The SHAP method showed that CRP, the modified five-item frailty index (mFI-5), and ASA body status were among the top three important predicators of POP.

CONCLUSION

Our model's good early prediction ability, combined with the implementation of a network risk calculator based on the Catboost model, was anticipated to effectively distinguish high-risk POP groups, facilitating timely intervention.

Dexmedetomidine Attenuates Inflammation in Elderly Patients Following Major Hepatobiliary and Pancreatic Surgery: A Randomized Clinical Trial

Background

Dexmedetomidine (Dex) may have anti-inflammatory properties and potentially reduce the incidence of postoperative organ injury.

Objective

To investigate whether Dex protects pulmonary and renal function via its anti-inflammatory effects in elderly patients undergoing prolonged major hepatobiliary and pancreatic surgery.

Design and Setting

Between October 2019 and December 2020, this randomized controlled trial was carried out at a tertiary hospital in Chongqing, China.

Patients

86 patients aged 60-75 who underwent long-duration (> 4 hrs) hepatobiliary and pancreatic surgery without significant comorbidities were enrolled and randomly assigned into two groups at a 1:1 ratio.

Interventions

Patients were given either Dex or an equivalent volume of 0.9% saline (Placebo) with a loading dose of 1 μg kg-1 for 10 min, followed by 0.5 μg kg-1 hr-1 for maintenance until the end of surgery.

Main Outcome Measures

The changes in serum concentrations of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) were primary outcomes.

Results

At one hour postoperatively, serum IL-6 displayed a nine-fold increase (P<0.05) in the Placebo group. Administration of Dex decreased IL-6 to 278.09 ± 45.43 pg/mL (95% CI: 187.75 to 368.43) compared to the Placebo group (P=0.019; 432.16 ± 45.43 pg/mL, 95% CI: 341.82 to 522.50). However, no significant differences in TNF-α were observed between the two groups. The incidence of postoperative acute kidney injury was twice as high in the Placebo group (9.30%) compared to the Dex group (4.65%), and the incidence of postoperative acute lung injury was 23.26% in the Dex group, lower than that in the Placebo group (30.23%), although there was no statistical significance between the two groups.

Conclusion

Dex administration in elderly patients undergoing major hepatobiliary and pancreatic surgery reduces inflammation and potentially protects kidneys and lungs.

Registration

Chinese Clinical Trials Registry, identifier: ChiCTR1900024162, on 28 June 2019.

Body Mass Index Greater Than 46 Associated With Increased Risk of 30 Day Complications Following Adult Tonsillectomy: A Retrospective Cohort Study

Background: The study aimed to identify data-driven body mass index (BMI) thresholds that are associated with varying risk of 30 day complications following adult tonsillectomy. Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was utilized to conduct a retrospective cohort analysis of patients undergoing adult tonsillectomy from 2005 to 2019. Stratum-specific likelihood ratio (SSLR) analysis was conducted to determine data-driven BMI strata that maximized the likelihood of 30 day complications following adult tonsillectomy. Patient demographics and clinical comorbidities were compared using chi-squared analysis and student t tests, where appropriate, for each stratum. Multivariable regression analysis was conducted to confirm association between identified data-driven strata with 30 day complication rates. Results: In total, 44,161 patients undergoing adult tonsillectomy were included in this study. SSLR analysis identified 2 BMI categories: 18 to 45 and 46+. Relative to the 18 to 45 BMI cohort, the 46+ BMI cohort was more likely to have 30 day all-cause complications after surgery [odds ratio (OR): 1.62, P = .007]. Specifically, the 46+ BMI cohort had significantly higher odds for 30 day major medical complications (OR: 2.86, P = .001), pulmonary domain complications (OR: 1.86, P = .041), unplanned reintubation (OR: 2.65, P = .033), and deep vein thrombosis (OR: 6.54, P = .026). Conclusions: We identified a BMI threshold of 46+ that was associated with a significantly increased risk of 30 day all-cause complications following adult tonsillectomy. These BMI strata can guide preoperative planning and risk-stratifying models for predicting 30 day complications in tonsillectomy surgery.

[Preoperative evaluation of adult patients before elective, non-cardiothoracic surgery : A joint recommendation of the German Society for Anesthesiology and Intensive Care Medicine, the German Society for Surgery and the German Society for Internal Medicine]

The 70 recommendations summarize the current status of preoperative risk evaluation of adult patients prior to elective non-cardiothoracic surgery. Based on the joint publications of the German scientific societies for anesthesiology and intensive care medicine (DGAI), surgery (DGCH), and internal medicine (DGIM), which were first published in 2010 and updated in 2017, as well as the European guideline on preoperative cardiac risk evaluation published in 2022, a comprehensive re-evaluation of the recommendation takes place, taking into account new findings, the current literature, and current guidelines of international professional societies. The revised multidisciplinary recommendation is intended to facilitate a structured and common approach to the preoperative evaluation of patients. The aim is to ensure individualized preparation for the patient prior to surgery and thus to increase patient safety. Taking into account intervention- and patient-specific factors, which are indispensable in the preoperative risk evaluation, the perioperative risk for the patient should be minimized and safety increased. The recommendations for action are summarized under "General Principles (A)," "Advanced Diagnostics (B)," and the "Preoperative Management of Continuous Medication (C)." For the first time, a rating of the individual measures with regard to their clinical relevance has been given in the present recommendation. A joint and transparent agreement is intended to ensure a high level of patient orientation while avoiding unnecessary preliminary examinations, to shorten preoperative examination procedures, and ultimately to save costs. The joint recommendation of DGAI, DGCH and DGIM reflects the current state of knowledge as well as the opinion of experts. The recommendation does not replace the individualized decision between patient and physician about the best preoperative strategy and treatment.

One versus two vein anastomoses in breast reconstruction with a profunda artery perforator flap-does it make a difference

BACKGROUND

The profunda artery perforator (PAP) flap has gained popularity as a reliable alternative in breast reconstruction. Extensive research has focused on its vascular supply, dissection techniques, and broader applications beyond breast reconstruction. This study aims to investigate the correlation between the number of veins anastomosed for the PAP flap and postoperative complications.

METHODS

A retrospective study was conducted to evaluate the outcomes of breast reconstructions with PAP flaps at our institution between 2018 and 2022. A total of 103 PAP flaps in 88 patients were included. Statistical analysis was performed to compare outcomes between flaps with one vein anastomosis and those with two vein anastomoses. Patient characteristics, intra and postoperative parameters were analysed.

RESULTS

One vein anastomosis was used in 36 flaps (35.0%), whereas two vein anastomoses were used in 67 flaps (65.0%). No significant differences were found in patient characteristics between the one vein and two vein groups. The comparison of ischemia times between flaps with one versus two veins revealed no statistically significant difference, with mean ischemia times of 56.2 ± 36.8 min and 58.7 ± 33.0 min, respectively. Regarding outcomes, there were no statistically significant differences in secondary lipofilling, revision of vein anastomosis, or total flap loss between the two groups. Fat necrosis was observed in 5 (13.9%) one vein flaps and 5 (7.5%) two vein flaps, indicating no statistically significant difference between the two groups (p = .313). In the one vein group, the most frequently employed coupler ring had a diameter of 2.5 mm. In the two vein group, the most prevalent combination consisted of a 2.0 mm diameter with a 2.5 mm diameter.

CONCLUSION

Based on our study results, both one vein anastomosis and two vein anastomoses are viable options for breast reconstruction with PAP flap. The utilization of either one or two veins did not significantly affect ischemia time or flap loss. Fat necrosis exhibited a higher incidence in the single-vein group; however, this difference was also not statistically significant. These findings underscore the effectiveness of both approaches, providing surgeons with flexibility in tailoring their surgical techniques based on patient-specific considerations and anatomical factors.

Remote ischaemic preconditioning for transcatheter aortic valve replacement: a protocol for a systematic review with meta-analysis and trial sequential analysis

INTRODUCTION

Transcatheter aortic valve replacement (TAVR) has become an important treatment in patients with aortic valve disease with the continuous advancement of technology and the improvement of outcomes. However, TAVR-related complications still increase patient morbidity and mortality. Remote ischaemic preconditioning (RIPC) is a simple procedure that provides perioperative protection for many vital organs. However, the efficiency of RIPC on TAVR remains unclear based on inconsistent conclusions from different clinical studies. Therefore, we will perform a protocol for a systematic review and meta-analysis to identify the efficiency of RIPC on TAVR.

METHODS AND ANALYSIS

English databases (PubMed, Web of Science, Ovid Medline, Embase and Cochrane Library), Chinese electronic databases (Wanfang Database, VIP Database and China National Knowledge Infrastructure) and trial registry databases will be searched from inception to December 2023 to identify randomised controlled trials of RIPC on TAVR. We will calculate mean differences or standardised mean differences with 95% CIs for continuous data, and the risk ratio (RR) with 95% CIs for dichotomous data by Review Manager version 5.4. Fixed-effects model or random-effects model will be used according to the degree of statistical heterogeneity assessed by the I-square test. We will evaluate the risk of bias using the Cochrane risk-of-bias tool 2 and assess the evidence quality of each outcome by the Grading of Recommendations Assessment, Development and Evaluation. The robustness of outcomes will be evaluated by trial sequential analysis. In addition, we will evaluate the publication bias of outcomes by Funnel plots and Egger's regression test.

ETHICS AND DISSEMINATION

Ethical approval was not required for this systematic review protocol. The results will be disseminated through peer-reviewed publications.

PROSPERO REGISTRATION NUMBER

CRD42023462926.

Noninvasive respiratory support in the perioperative setting: a narrative review

The application of preoperative noninvasive respiratory support (NRS) has been expanding with increasing recognition of its potential role in this setting as a physiological optimization for patients with a high risk of developing atelectasis and postoperative pulmonary complications (PPC). The increased availability of high-performance anesthesia ventilator machines providing an easy way for NRS support in patients with reduced lung function should not be under-evaluated. This support can reduce hypoxia, restore lung volumes and theoretically reduce atelectasis formation after general anesthesia. Therapeutic purposes should also be considered in the perioperative setting, such as preoperative NRS to optimize treatment of patients' pre-existing diseases, e.g., sleep-disordered breathing. Finally, the recent guidelines for airway management suggest preoperative NRS application before anesthesia induction in difficult airway management to prolong the time needed to secure the airway with an orotracheal tube. This narrative review aims to revise all these aspects and to provide some practical notes to maximize the efficacy of perioperative noninvasive respiratory support.

Comparison of three frailty scales for prediction of prolonged postoperative ileus following major abdominal surgery in elderly patients: a prospective cohort study

BACKGROUND

To determine whether frailty can predict prolonged postoperative ileus (PPOI) in older abdominal surgical patients; and to compare predictive ability of the FRAIL scale, the five-point modified frailty index (mFI-5) and Groningen Frailty Indicator (GFI) for PPOI.

METHODS

Patients (aged ≥ 65 years) undergoing major abdominal surgery at our institution between April 2022 to January 2023 were prospectively enrolled. Frailty was evaluated with FRAIL, mFI-5 and GFI before operation. Data on demographics, comorbidities, perioperative management, postoperative recovery of bowel function and PPOI occurrence were collected.

RESULTS

The incidence of frailty assessed with FRAIL, mFI-5 and GFI was 18.2%, 38.4% and 32.5% in a total of 203 patients, respectively. Ninety-five (46.8%) patients experienced PPOI. Time to first soft diet intake was longer in patients with frailty assessed by the three scales than that in patients without frailty. Frailty diagnosed by mFI-5 [Odds ratio (OR) 3.230, 95% confidence interval (CI) 1.572-6.638, P = 0.001] or GFI (OR 2.627, 95% CI 1.307-5.281, P = 0.007) was related to a higher risk of PPOI. Both mFI-5 [Area under curve (AUC) 0.653, 95% CI 0.577-0.730] and GFI (OR 2.627, 95% CI 1.307-5.281, P = 0.007) had insufficient accuracy for the prediction of PPOI in patients undergoing major abdominal surgery.

CONCLUSIONS

Elderly patients diagnosed as frail on the mFI-5 or GFI are at an increased risk of PPOI after major abdominal surgery. However, neither mFI-5 nor GFI can accurately identify individuals who will develop PPOI.

TRIAL REGISTRATION

This study was registered in Chinese Clinical Trial Registry (No. ChiCTR2200058178). The date of first registration, 31/03/2022, https://www.chictr.org.cn/ .

The impact of previous COVID-19 pneumonia on postoperative outcomes and complications in coronary artery bypass grafting

Background

This study aimed to provide nuanced insights in managing patients with a history of coronavirus disease 2019 (COVID-19) pneumonia undergoing coronary artery bypass grafting.

Methods

This retrospective cohort study involved 168 patients (131 males, 37 females; mean age: 61.2±9.7 years; range, 51 to 72 years) undergoing isolated coronary artery bypass grafting surgery between December 2021 and December 2023. The study examined factors such as age, sex, comorbidities, blood test results, vaccination status, operative parameters, and postoperative complications. Patients' health records were reviewed to confirm the presence of previous COVID-19 pneumonia and vaccination status. Patients were divided into two groups based on their history of COVID-19 pneumonia: Group 1 included 140 who had not been diagnosed with COVID-19 pneumonia, and Group 2 included 28 patients who had a documented history of COVID-19 pneumonia. Postoperative pulmonary complications, including atelectasis, pleural effusion, acute respiratory distress syndrome, and pneumonia, were noted.

Results

Patients with a history of COVID-19 pneumonia (Group 2, n=28) demonstrated significantly higher seropositivity for COVID-19 (89.3% vs. 29.3%, p=0.001) compared to those without a history (Group 1, n=140). Although pulmonary complications were higher in Group 2 (17.9% vs. 3.6%, p=0.013), postoperative mortality rates did not differ significantly between the groups. Pleural effusion was markedly higher in Group 2 (14.3% vs. 2.1%, p=0.015). Vaccination did not significantly affect perioperative and postoperative outcomes, except for a minor difference in postoperative drainage volume.

Conclusion

This study highlights the impact of prior COVID-19 pneumonia on postoperative outcomes in coronary artery bypass grafting patients. Although there was a rise in pulmonary complications, the mortality rates stayed similar among individuals with and without a prior history of COVID-19 pneumonia. Vaccination did not significantly influence outcomes, emphasizing the need for further research with larger cohorts to validate and expand upon these findings.

Association of ketamine use during procedural sedation with oxygen desaturation and healthcare utilisation: a multicentre retrospective hospital registry study

BACKGROUND

We investigated the effects of ketamine on desaturation and the risk of nursing home discharge in patients undergoing procedural sedation by anaesthetists.

METHODS

We included adult patients who underwent procedures under monitored anaesthetic care between 2005 and 2021 at two academic healthcare networks in the USA. The primary outcome was intraprocedural oxygen desaturation, defined as oxygen saturation <90% for ≥2 consecutive minutes. The co-primary outcome was a nursing home discharge.

RESULTS

Among 234,170 included patients undergoing procedural sedation, intraprocedural desaturation occurred in 5.6% of patients who received ketamine vs 5.2% of patients who did not receive ketamine (adjusted odds ratio [ORadj] 1.22, 95% confidence interval [CI] 1.15-1.29, P<0.001; adjusted absolute risk difference [ARDadj] 1%, 95% CI 0.7-1.3%, P<0.001). The effect was magnified by age >65 yr, smoking, or preprocedural ICU admission (P-for-interaction <0.001, ORadj 1.35, 95% CI 1.25-1.45, P<0.001; ARDadj 2%, 95% CI 1.56-2.49%, P<0.001), procedural risk factors (upper endoscopy of longer than 2 h; P-for-interaction <0.001, ORadj 2.91, 95% CI 1.85-4.58, P<0.001; ARDadj 16.2%, 95% CI 9.8-22.5%, P<0.001), and high ketamine dose (P-for-trend <0.001, ORadj 1.61, 95% CI, 1.43-1.81 for ketamine >0.5 mg kg-1). Concomitant opioid administration mitigated the risk (P-for-interaction <0.001). Ketamine was associated with higher odds of nursing home discharge (ORadj 1.11, 95% CI 1.02-1.21, P=0.012; ARDadj 0.25%, 95% CI 0.05-0.46%, P=0.014).

CONCLUSIONS

Ketamine use for procedural sedation was associated with an increased risk of oxygen desaturation and discharge to a nursing home. The effect was dose-dependent and magnified in subgroups of vulnerable patients.

Systematic development and validation of a predictive model for major postoperative complications in the Peri-operative Quality Improvement Project (PQIP) dataset

Complications are common following major surgery and are associated with increased use of healthcare resources, disability and mortality. Continued reliance on mortality estimates risks harming patients and health systems, but existing tools for predicting complications are unwieldy and inaccurate. We aimed to systematically construct an accurate pre-operative model for predicting major postoperative complications; compare its performance against existing tools; and identify sources of inaccuracy in predictive models more generally. Complete patient records from the UK Peri-operative Quality Improvement Programme dataset were analysed. Major complications were defined as Clavien-Dindo grade ≥ 2 for novel models. In a 75% train:25% test split cohort, we developed a pipeline of increasingly complex models, prioritising pre-operative predictors using Least Absolute Shrinkage and Selection Operators (LASSO). We defined the best model in the training cohort by the lowest Akaike's information criterion, balancing accuracy and simplicity. Of the 24,983 included cases, 6389 (25.6%) patients developed major complications. Potentially modifiable risk factors (pain, reduced mobility and smoking) were retained. The best-performing model was highly complex, specifying individual hospital complication rates and 11 patient covariates. This novel model showed substantially superior performance over generic and specific prediction models and scores. We have developed a novel complications model with good internal accuracy, re-prioritised predictor variables and identified hospital-level variation as an important, but overlooked, source of inaccuracy in existing tools. The complexity of the best-performing model does, however, highlight the need for a step-change in clinical risk prediction to automate the delivery of informative risk estimates in clinical systems.

Intraoperative lung protection: strategies and their impact on outcomes

PURPOSE OF REVIEW

The present review summarizes the current knowledge and the barriers encountered when implementing tailoring lung-protective ventilation strategies to individual patients based on advanced monitoring systems.

RECENT FINDINGS

Lung-protective ventilation has become a pivotal component of perioperative care, aiming to enhance patient outcomes and reduce the incidence of postoperative pulmonary complications (PPCs). High-quality research has established the benefits of strategies such as low tidal volume ventilation and low driving pressures. Debate is still ongoing on the most suitable levels of positive end-expiratory pressure (PEEP) and the role of recruitment maneuvers. Adapting PEEP according to patient-specific factors offers potential benefits in maintaining ventilation distribution uniformity, especially in challenging scenarios like pneumoperitoneum and steep Trendelenburg positions. Advanced monitoring systems, which continuously assess patient responses and enable the fine-tuning of ventilation parameters, offer real-time data analytics to predict and prevent impending lung complications. However, their impact on postoperative outcomes, particularly PPCs, is an ongoing area of research.

SUMMARY

Refining protective lung ventilation is crucial to provide patients with the best possible care during surgery, reduce the incidence of PPCs, and improve their overall surgical journey.

Effect of incremental PEEP titration on postoperative pulmonary complications in patients undergoing emergency laparotomy: a randomized controlled trial

Postoperative pulmonary complications (PPC) has a significant negative impact and are associated with increased length of hospital stay and cost of care. Emergency surgery is a well-established risk factor for PPC. Previous studies reported that personalized positive end-expiratory pressure (PEEP) might reduce postoperative atelectasis and postoperative pulmonary complications. N = 168 adult patients undergoing major emergency laparotomy under general anesthesia were recruited in this study. A minimum driving pressure based incremental PEEP titration was compared to a fixed PEEP of 5 cmH2O. The primary outcome was PPC up to postoperative day 7. The mean (standard deviation) of the recruited patients was 41.7(16.1)y, and 48.8% (82 of 168 patients) were female. The risk of PPC at postoperative day 7 was similar in both the study groups [Relative risk (RR) (95% Confidence interval, CI) 0.81 (0.58, 1.13); p = 0.25]. In addition, the incidence of intraoperative hypotension [p = 0.75], oxygen-free days at day 28 [p = 0.27], duration of postoperative hospital stay [p = 0.50], length of postoperative intensive care unit stay [p = 0.28], and in-hospital mortality [p = 0.38] were similar in two groups. Incidence of PPC was not reduced with the use of an individualized PEEP strategy based on lowest driving pressure. However, the incidence of hypotension and bradycardia was also not increased with titrated PEEP.Trial Registration: www.ctri.nic.in ; CTRI/2020/12/029765.

Pulmonary Hypertension and the Risk of 30-Day Postoperative Pulmonary Complications after Gastrointestinal Surgical or Endoscopic Procedures: A Retrospective Propensity Score-Weighted Cohort Analysis

Background: Pulmonary hypertension (PH) patients are at higher risk of postoperative complications. We analyzed the association of PH with 30-day postoperative pulmonary complications (PPCs). Methods: A single-center propensity score overlap weighting (OW) retrospective cohort study was conducted on 164 patients with a mean pulmonary artery pressure (mPAP) of >20 mmHg within 24 months of undergoing elective inpatient abdominal surgery or endoscopic procedures under general anesthesia and a control cohort (N = 1981). The primary outcome was PPCs, and the secondary outcomes were PPC sub-composites, namely respiratory failure (RF), pneumonia (PNA), aspiration pneumonia/pneumonitis (ASP), pulmonary embolism (PE), length of stay (LOS), and 30-day mortality. Results: PPCs were higher in the PH cohort (29.9% vs. 11.2%, p < 0.001). When sub-composites were analyzed, higher rates of RF (19.3% vs. 6.6%, p < 0.001) and PNA (11.2% vs. 5.7%, p = 0.01) were observed. After OW, PH was still associated with greater PPCs (RR 1.66, 95% CI (1.05-2.71), p = 0.036) and increased LOS (median 8.0 days vs. 4.9 days) but not 30-day mortality. Sub-cohort analysis showed no difference in PPCs between pre- and post-capillary PH patients. Conclusions: After covariate balancing, PH was associated with a higher risk for PPCs and prolonged LOS. This elevated PPC risk should be considered during preoperative risk assessment.

Safety of lung resection surgery after severe acute respiratory syndrome coronavirus 2 infection in the post-vaccination era

OBJECTIVES

To investigate the postoperative outcomes of lung resection in patients with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and determine the optimal timing of surgery.

METHODS

This retrospective, single-centre cohort study included patients who underwent lung resection between June 2021 and June 2022. Patients were divided into the coronavirus disease 2019 (COVID-19) and non-COVID-19 groups based on their preoperative SARS-CoV-2 infection history, and postoperative outcomes were compared. Logistic regression analysis was conducted to identify the risk factors of complications after lung resection surgery.

RESULTS

In total, 1194 patients were enrolled, of whom, 79 had a history of SARS-CoV-2 infection. In the COVID-19 group, 66 patients (90.4%) had received at least 1 vaccination dose. The average interval between infection and surgery was 67 days, with no significant impact on postoperative outcomes. Regarding postoperative outcomes, there were no significant differences in major complication rate (6.3% vs 5.4%, P = 0.613), respiratory complication rate (19.0% vs 12.2%, P = 0.079) or length of stays (4.9 ± 3.4 vs 5.0 ± 5.6, P = 0.992) between the 2 groups. Multivariate logistic regression analysis revealed that age, male sex, poor pulmonary function test, open surgery and extensive lung resection were risk factors for postoperative complications, while preoperative COVID-19 infection status was not a statistically significant risk factor.

CONCLUSIONS

In the post-vaccination era, lung resection surgery can be safely performed shortly after SARS-CoV-2 infection, even within 4 weeks of infection.

A predictive model for post-thoracoscopic surgery pulmonary complications based on the PBNN algorithm

We constructed an early prediction model for postoperative pulmonary complications after thoracoscopic surgery using machine learning and deep learning algorithms. The artificial intelligence prediction models were built in Python, primarily using artificial intelligencealgorithms including both machine learning and deep learning algorithms. Correlation analysis showed that postoperative pulmonary complications were positively correlated with age and surgery duration, and negatively correlated with serum albumin. Using the light gradient boosting machine(LGBM) algorithm, weighted feature engineering revealed that single lung ventilation duration, history of smoking, surgery duration, ASA score, and blood glucose were the main factors associated with postoperative pulmonary complications. Results of artificial intelligence algorithms for predicting pulmonary complications after thoracoscopy in the test group: In terms of accuracy, the two best algorithms were Logistic Regression (0.831) and light gradient boosting machine(0.827); in terms of precision, the two best algorithms were Gradient Boosting (0.75) and light gradient boosting machine (0.742); in terms of recall, the three best algorithms were gaussian naive bayes (0.581), Logistic Regression (0.532), and pruning Bayesian neural network (0.516); in terms of F1 score, the two best algorithms were LogisticRegression (0.589) and pruning Bayesian neural network (0.566); and in terms of Area Under Curve(AUC), the two best algorithms were light gradient boosting machine(0.873) and pruning Bayesian neural network (0.869). The results of this study suggest that pruning Bayesian neural network (PBNN) can be used to assess the possibility of pulmonary complications after thoracoscopy, and to identify high-risk groups prior to surgery.

Postoperative pulmonary complications in patients undergoing upper abdominal surgery: risk factors and predictive models

Postoperative pulmonary complications (PPCs) are unexpected disorders that occur up to 30 days after surgery, affecting the patient's clinical status and requiring therapeutic intervention. Therefore, it becomes important to assess the patient preoperatively, as many of these complications can be minimized with proper perioperative strategies following a thorough preoperative checkup. Herein, we describe the PPCs and risk factors associated with developing PPCs in patients undergoing upper abdominal surgery. Additionally, we compared the accuracy of the American Society of Anaesthesiologists (ASA) score, the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) score, the 6-Minute Walk Test (6MWT), and spirometry in predicting PPCs. Consenting patients (>18 years) undergoing elective upper abdominal surgery were recruited from November 2021 to April 2023. Clinical history was noted. Spirometry and 6MWT were both performed. Pre-operative ASA and ARISCAT scores were recorded. Postoperative follow-up was conducted to assess respiratory symptoms and the occurrence of PPC. PPC was defined as per EPCO guidelines. A total of 133 patients were recruited, predominantly male. A total of 27 (20.3%) patients developed PPCs. A total of 14 (10.5%) patients had more than one PPC. The most common PPCs developed were pleural effusion (11.3%), respiratory failure (7.5%), and pneumonia (4.5%). We obtained ten statistically significant associated variables on univariable analysis, viz obstructive airway disease (p=0.002), airflow limitation (p=0.043), chest radiography (p<0.001), albumin (p=0.30), blood urea nitrogen (BUN) (p=0.029), aspartate aminotransferase (p=0.019), alanine aminotransferase (p=0.009), forced expiratory volume in one second/forced vital capacity ratio (p=0.006), duration of surgery (p<0.001), and ASA score (p=0.012). On multivariable regression analysis, abnormal chest radiograph [odds ratio: 8.26; (95% confidence interval: 2.58-25.43), p<0.001], BUN [1.05; (1.00-1.09), p=0.033], and duration of surgery [1.44; (1.18-1.76), p<0.001] were found to be independently associated with PPC. The ASA score was found to have better predictive power for the development of PPCs compared to the ARISCAT score but is of poor clinical significance. Additionally, 6MWD and spirometry results were found to lack any meaningful predictive power for PPC. To conclude, preoperative evaluation of the chest radiograph, BUN, and duration of surgery are independently associated with developing PPCs. The ASA score performs better than the ARISCAT score in identifying patients at a higher risk of developing PPCs and implementing preventive measures.

Effects of Intra-operative Cardiopulmonary Variability On Post-operative Pulmonary Complications in Major Non-cardiac Surgery: A Retrospective Cohort Study

Intraoperative cardiopulmonary variables are well-known predictors of postoperative pulmonary complications (PPC), traditionally quantified by median values over the duration of surgery. However, it is unknown whether cardiopulmonary instability, or wider intra-operative variability of the same metrics, is distinctly associated with PPC risk and severity. We leveraged a retrospective cohort of adults (n = 1202) undergoing major non-cardiothoracic surgery. We used multivariable logistic regression to evaluate the association of two outcomes (1)moderate-or-severe PPC and (2)any PPC with two sets of exposure variables- (a)variability of cardiopulmonary metrics (inter-quartile range, IQR) and (b)median intraoperative cardiopulmonary metrics. We compared predictive ability (receiver operating curve analysis, ROC) and parsimony (information criteria) of three models evaluating different aspects of the intra-operative cardiopulmonary metrics: Median-based: Median cardiopulmonary metrics alone, Variability-based: IQR of cardiopulmonary metrics alone, and Combined: Medians and IQR. Models controlled for peri-operative/surgical factors, demographics, and comorbidities. PPC occurred in 400(33%) of patients, and 91(8%) experienced moderate-or-severe PPC. Variability in multiple intra-operative cardiopulmonary metrics was independently associated with risk of moderate-or-severe, but not any, PPC. For moderate-or-severe PPC, the best-fit predictive model was the Variability-based model by both information criteria and ROC analysis (area under the curve, AUCVariability-based = 0.74 vs AUCMedian-based = 0.65, p = 0.0015; AUCVariability-based = 0.74 vs AUCCombined = 0.68, p = 0.012). For any PPC, the Median-based model yielded the best fit by information criteria. Predictive accuracy was marginally but not significantly higher for the Combined model (AUCCombined = 0.661) than for the Median-based (AUCMedian-based = 0.657, p = 0.60) or Variability-based (AUCVariability-based = 0.649, p = 0.29) models. Variability of cardiopulmonary metrics, distinct from median intra-operative values, is an important predictor of moderate-or-severe PPC.

A Transcriptomic Approach to Understand Patient Susceptibility to Pneumonia After Abdominal Surgery

OBJECTIVE

To describe immune pathways and gene networks altered following major abdominal surgery and to identify transcriptomic patterns associated with postoperative pneumonia.

BACKGROUND

Nosocomial infections are a major healthcare challenge, developing in over 20% of patients aged 45 or over undergoing major abdominal surgery, with postoperative pneumonia associated with an almost 5-fold increase in 30-day mortality.

METHODS

From a prospective consecutive cohort (n=150) undergoing major abdominal surgery, whole-blood RNA was collected preoperatively and at 3 time-points postoperatively (2-6, 24, and 48 h). Twelve patients diagnosed with postoperative pneumonia and 27 matched patients remaining infection-free were identified for analysis with RNA-sequencing.

RESULTS

Compared to preoperative sampling, 3639 genes were upregulated and 5043 downregulated at 2 to 6 hours. Pathway analysis demonstrated innate-immune activation with neutrophil degranulation and Toll-like-receptor signaling upregulation alongside adaptive-immune suppression. Cell-type deconvolution of preoperative RNA-sequencing revealed elevated S100A8/9-high neutrophils alongside reduced naïve CD4 T-cells in those later developing pneumonia. Preoperatively, a gene-signature characteristic of neutrophil degranulation was associated with postoperative pneumonia acquisition ( P =0.00092). A previously reported Sepsis Response Signature (SRSq) score, reflecting neutrophil dysfunction and a more dysregulated host response, at 48 hours postoperatively, differed between patients subsequently developing pneumonia and those remaining infection-free ( P =0.045). Analysis of the novel neutrophil gene-signature and SRSq scores in independent major abdominal surgery and polytrauma cohorts indicated good predictive performance in identifying patients suffering later infection.

CONCLUSIONS

Major abdominal surgery acutely upregulates innate-immune pathways while simultaneously suppressing adaptive-immune pathways. This is more prominent in patients developing postoperative pneumonia. Preoperative transcriptomic signatures characteristic of neutrophil degranulation and postoperative SRSq scores may be useful predictors of subsequent pneumonia risk.

Evaluation of factors influencing long-term and textbook outcomes in laparoscopic gastrectomy

BACKGROUND

Textbook outcome (TO) in gastric cancer surgery is a multidimensional measure of surgical quality. However, its impact on long-term survival after laparoscopic gastrectomy (LG) is unclear. This study aims to evaluate TO in LG, assess its hospital-level relevance, and examine its association with long-term survival.

METHODS

In this retrospective cohort study, we analyzed 2278 consecutive gastric cancer patients who underwent laparoscopic gastrectomy (LG) from January 2004 to December 2017. We determined TO achievement rates, compared preoperative and intraoperative variables between TO and non-TO groups, identified independent predictors of TO, and assessed long-term oncologic outcomes using Kaplan-Meier analysis and Cox regression.

RESULTS

A total of 1540 LG patients were analyzed, with 994 (64.5%) achieving TO. The least frequently achieved metric was 'hospital stays ≤21 days' (83.4%), followed by 'lymph nodes retrieved ≥15' (84.0%). Factors independently associated with reduced TO likelihood included age ≥65 years, BMI ≥25, ASA III, conversion to open surgery, operation time ≥260 min, and estimated blood loss ≥150 ml. Furthermore, TO was independently linked to improved 5-year overall survival (OS) and disease-free survival (DFS) (HR 0.519 [0.443-0.609] and HR 0.517 [0.443-0.604], respectively).

CONCLUSION

Implementing the TO concept in LG provides a benchmark for achieving improved prognoses and empowers surgeons to devise strategies for enhancing surgical care quality.

Lung Ultrasound Score on Postoperative Day 1 Is Predictive of the Occurrence of Pulmonary Complications after Major Abdominal Surgery: A Multicenter Prospective Observational Study

BACKGROUND

Postoperative pulmonary complications after major abdominal surgery are frequent and carry high morbidity and mortality. Early identification of patients at risk of pulmonary complications by lung ultrasound may allow the implementation of preemptive strategies. The authors hypothesized that lung ultrasound score would be associated with pulmonary postoperative complications. The main objective of the study was to evaluate the performance of lung ultrasound score on postoperative day 1 in predicting pulmonary complications after major abdominal surgery. Secondary objectives included the evaluation of other related measures for their potential prediction accuracy.

METHODS

A total of 149 patients scheduled for major abdominal surgery were enrolled in a bicenter observational study. Lung ultrasound score was performed before the surgery and on days 1, 4, and 7 after surgery. Pulmonary complications occurring before postoperative day 10 were recorded.

RESULTS

Lung ultrasound score on postoperative day 1 was higher in patients developing pulmonary complications before day 10 (median, 13; interquartile range, 8.25 to 18; vs. median, 10; interquartile range, 6.5 to 12; Mann-Whitney P = 0.002). The area under the curve for predicting postoperative pulmonary complications before day 10 was 0.65 (95% CI, 0.55 to 0.75; P = 0.003). Lung ultrasound score greater than 12 had a sensitivity of 0.54 (95% CI, 0.40 to 0.67), specificity of 0.77 (95% CI, 0.67 to 0.85), and negative predictive value of 0.74 (95% CI, 0.65 to 0.83). Lung ultrasound score greater than 17 had sensitivity of 0.33 (95% CI, 0.21 to 0.47), specificity of 0.95 (95% CI, 0.88 to 0.98), and positive predictive value of 0.78 (95% CI, 0.56 to 0.93). Anterolateral lung ultrasound score and composite scores using lung ultrasound score and other patient characteristics showed similar predictive accuracies.

CONCLUSIONS

An elevated lung ultrasound score on postoperative day 1 is associated with the occurrence of pulmonary complications within the first 10 days after major abdominal surgery.

EDITOR’S PERSPECTIVE

Intraoperative effects of an alveolar recruitment manoeuvre in patients undergoing laparoscopic colon surgery

INTRODUCTION

Pulmonary atelectasis is common in patients undergoing laparoscopic abdominal surgery under general anaesthesia, which increases the risk of perioperative respiratory complications. Alveolar recruitment manoeuvres (ARM) are used to open up the lung parenchyma with atelectasis, although the duration of their benefit has not been clearly established. The aim of this study was to determine the effectiveness of an ARM in laparoscopic colon surgery, the duration of response over time, and its haemodynamic impact.

METHODS

Twenty-five patients undergoing laparoscopic colon surgery were included. After anaesthetic induction and initiation of surgery with pneumoperitoneum, an ARM was performed, and then optimal PEEP determined. Respiratory mechanics and gas exchange variables, and haemodynamic parameters, were analysed before the manoeuvre and periodically over the following 90 min.

RESULTS

Three patients were excluded for surgical reasons. The alveolar arterial oxygen gradient went from 94.3 (62.3-117.8) mmHg before to 60.7 (29.6-91.0) mmHg after the manoeuvre (P < .05). This difference was maintained during the 90 min of the study. Dynamic compliance of the respiratory system went from 31.3 ml/cmH2O (26.1-39.2) before the manoeuvre to 46.1 ml/cmH2O (37.5-53.5) after the manoeuvre (P < .05). This difference was maintained for 60 min. No significant changes were identified in any of the haemodynamic variables studied.

CONCLUSION

In patients undergoing laparoscopic colon surgery, performing an intraoperative ARM improves the mechanics of the respiratory system and oxygenation, without associated haemodynamic compromise. The benefit of these manoeuvres lasts for at least one hour.

Peripheral Nerve Blockade for Open Inguinal Hernia Repair in a Patient With Severe Cardiopulmonary Disease

Patients with severe cardiopulmonary morbidity present a unique challenge to peri- and intraoperative providers. Inducing general anesthesia in this patient population poses the risk of adverse events that could lead to poor surgical outcomes, prolonged debilitation, or death. Therefore, it is important that anesthesiologists become comfortable with preoperative evaluation as well as alternative strategies to providing surgical anesthesia. This case report details the clinical course of a patient with severe cardiopulmonary morbidity who underwent open inguinal hernia repair without oral or intravenous sedation after receiving multi-level paravertebral blocks in addition to isolated ilioinguinal and iliohypogastric nerve blocks. This medically challenging case provides educational value regarding preoperative evaluation, pertinent anatomy and innervation, and the importance of patient-centered care and communication.

Use of thoracic fluid content for prediction of fluid balance and postoperative pulmonary complications after major abdominal surgery: an observational study

BACKGROUND AND OBJECTIVES

The harmful effects of excess fluids frequently manifest in the lungs. Thoracic fluid content (TFC) is a variable provided by the STARLINGTM bioreactance monitor, which represents the total volume of fluid in the chest. The objective is to analyse the association between the variation in TFC values (TFCd0%) at 24 h postoperatively, postoperative fluid balance, and postoperative pulmonary complications.

MATERIAL AND METHODS

Prospective and analytical observational study. Patients scheduled for major abdominal surgery at a tertiary teaching hospital were included. They were monitored during the intervention and the first 24 postoperative hours with the monitor. STARLINGTM, measuring TFC and its variation in different stages of the perioperative period. Serial lung ultrasounds were performed and postoperative pulmonary complications were recorded. Logistic regression was performed to predict the occurrence of atelectasis and pulmonary congestion. The Pearson correlation coefficient was calculated to verify the association between TFC and fluid balance.

RESULTS

50 patients were analyzed. TFCd0% measured on the morning of the first postoperative day increased by a median of 27.1% [IQR: 20.3-37.5] and was correlated at r = 0.44 with the postoperative balance of 677 ml [IQR: 125.5-1,412]. Increased TFC was related to a higher risk of atelectasis (OR = 1.24) and pulmonary congestion (OR = 1.3).

CONCLUSIONS

TFCd0% measured 24 h after surgery presents a moderate correlation with postoperative fluid balance. Its increase is a risk factor for the appearance of postoperative pulmonary complications.

Intraoperative Mechanical Power and Postoperative Pulmonary Complications in Noncardiothoracic Elective Surgery Patients: A 10-Year Retrospective Cohort Study

BACKGROUND

Postoperative pulmonary complications is a major issue that affects outcomes of surgical patients. The hypothesis was that the intraoperative ventilation parameters are associated with occurrence of postoperative pulmonary complications.

METHODS

A single-center retrospective cohort study was conducted at the Lille University Hospital, France. The study included 33,701 adults undergoing noncardiac, nonthoracic elective surgery requiring general anesthesia with tracheal intubation between January 2010 and December 2019. Intraoperative ventilation parameters were compared between patients with and without one or more postoperative pulmonary complications (respiratory infection, respiratory failure, pleural effusion, atelectasis, pneumothorax, bronchospasm, and aspiration pneumonitis) within 7 days of surgery.

RESULTS

Among 33,701 patients, 2,033 (6.0%) had one or more postoperative pulmonary complications. The lower tidal volume to predicted body weight ratio (odds ratio per -1 ml·kgPBW-1, 1.08; 95% CI, 1.02 to 1.14; P < 0.001), higher mechanical power (odds ratio per 4 J·min-1, 1.37; 95% CI, 1.26 to 1.49; P < 0.001), dynamic respiratory system compliance less than 30 ml·cm H2O (1.30; 95% CI, 1.15 to 1.46; P < 0.001), oxygen saturation measured by pulse oximetry less than 96% (odds ratio, 2.42; 95% CI, 1.97 to 2.96; P < 0.001), and lower end-tidal carbon dioxide (odds ratio per -3 mmHg, 1.06; 95% CI, 1.00 to 1.13; P = 0.023) were independently associated with postoperative pulmonary complications. Patients with postoperative pulmonary complications were more likely to be admitted to the intensive care unit (odds ratio, 12.5; 95% CI, 6.6 to 10.1; P < 0.001), had longer hospital length of stay (subhazard ratio, 0.43; 95% CI, 0.40 to 0.45), and higher in-hospital (subhazard ratio, 6.0; 95% CI, 4.1 to 9.0; P < 0.001) and 1-yr mortality (subhazard ratio, 2.65; 95% CI, 2.33 to 3.02; P < 0.001).

CONCLUSIONS

In the study's population, decreased rather than increased tidal volume, decreased compliance, increased mechanical power, and decreased end-tidal carbon dioxide were independently associated with postoperative pulmonary complications.

EDITOR’S PERSPECTIVE

Intraoperative mechanical power and postoperative pulmonary complications in low-risk surgical patients: a prospective observational cohort study

BACKGROUND

Inadequate intraoperative mechanical ventilation (MV) can lead to ventilator-induced lung injury and increased risk for postoperative pulmonary complications (PPCs). Mechanical power (MP) was shown to be a valuable indicator for MV outcomes in critical care patients. The aim of this study is to assess the association between intraoperative MP in low-risk surgical patients undergoing general anesthesia and PPCs.

METHODS

Two-hundred eighteen low-risk surgical patients undergoing general anesthesia for elective surgery were included in the study. Intraoperative mechanical ventilatory support parameters were collected for all patients. Postoperatively, patients were followed throughout their hospital stay and up to seven days post discharge for the occurrence of any PPCs.

RESULTS

Out of 218 patients, 35% exhibited PPCs. The average body mass index, tidal volume per ideal body weight, peak inspiratory pressure, and MP were significantly higher in the patients with PPCs than in the patients without PPCs (30.3 ± 8.1 kg/m2 vs. 26.8 ± 4.9 kg.m2, p < 0.001; 9.1 ± 1.9 ml/kg vs. 8.6 ± 1.4 ml/kg, p = 0.02; 20 ± 4.9 cmH2O vs. 18 ± 3.7 cmH2O, p = 0.001; 12.9 ± 4.5 J/min vs. 11.1 ± 3.7 J/min, p = 0.002). A multivariable regression analysis revealed MP as the sole significant predictor for the risk of postoperative pulmonary complications [OR 1.1 (95% CI 1.0-1.2, p = 0.036].

CONCLUSIONS

High intraoperative mechanical power is a risk factor for developing postoperative pulmonary complications. Furthermore, intraoperative mechanical power is superior to other traditional mechanical ventilation variables in identifying surgical patients who are at risk for developing postoperative pulmonary complications.

CLINICAL TRIAL REGISTRATION

NCT03551899; 24/02/2017.

Qualitative assessment of expectations on the content, form and way of delivery of a prehabilitation programme in patients with lung resection surgery - A Swiss tertiary centre experience

Objective

To assess the interest in a prehabilitation programme of patients awaiting lung resection and to identify expectations from such a programme.

Introduction

At present, in Switzerland, there are no multimodal clinical prehabilitation programmes for lung resection patients awaiting surgery.

Methods

Semi-structured face-to-face interviews were conducted with patients who have had or were awaiting lung resection at a Swiss tertiary centre. Thematic analysis was performed to identify common prespecified themes.

Results

Twenty-two patients (45.5% female, age 70.6 ± 16.6 years) were interviewed. Seventy-seven percent were interested in a prehabilitation programme. Sixty-two percent, 67% and 90% were interested in endurance, strength and respiratory training, respectively. Six patients (27%) were active smokers, of whom two (one-third) were interested in a smoking cessation programme. Seventy-six percent were interested in nutrition counselling and 90% in receiving education on risk factor management. Forty percent preferred centre-based training/counselling sessions, 20% preferred home-based training/counselling and 30% found both forms acceptable. Patients were willing to perform prehabilitation activities on 2.6 days/week for a total of 162 min/week. Participating in peer groups was desired by only 25%.

Conclusions

Patients with lung resection were highly interested in participating in prehabilitation, albeit only for a mean time cost of 2.7 h per week. Offering a prehabilitation programme with a combination of in-hospital group sessions and home-based training seems feasible.

Nomogram for predicting postoperative pulmonary complications in spinal tumor patients

OBJECTIVES

Although several independent risk factors for postoperative pulmonary complications (PPCs) after spinal tumor surgery have been studied, a simple and valid predictive model for PPC occurrence after spinal tumor surgery has not been developed.

PATIENTS AND METHODS

We collected data from patients who underwent elective spine surgery for a spinal tumor between 2013 and 2020 at a tertiary hospital in China. Data on patient characteristics, comorbidities, preoperative examinations, intraoperative variables, and clinical outcomes were collected. We used univariable and multivariable logistic regression models to assess predictors of PPCs and developed and validated a nomogram for PPCs. We evaluated the performance of the nomogram using the area under the receiver operating characteristic curve (ROC), calibration curves, the Brier Score, and the Hosmer-Lemeshow (H-L) goodness-of-fit test. For clinical use, decision curve analysis (DCA) was conducted to identify the model's performance as a tool for supporting decision-making.

RESULTS

Among the participants, 61 (12.4%) individuals developed PPCs. Clinically significant variables associated with PPCs after spinal tumor surgery included BMI, tumor location, blood transfusion, and the amount of blood lost. The nomogram incorporating these factors showed a concordance index (C-index) of 0.755 (95% CI: 0.688-0.822). On internal validation, bootstrapping with 1000 resamples yielded a bias-corrected area under the receiver operating characteristic curve of 0.733, indicating the satisfactory performance of the nomogram in predicting PPCs. The calibration curve demonstrated accurate predictions of observed values. The decision curve analysis (DCA) indicated a positive net benefit for the nomogram across most predicted threshold probabilities.

CONCLUSIONS

We have developed a new nomogram for predicting PPCs in patients who undergo spinal tumor surgery.

Respiratory mechanics and mechanical power during low vs. high positive end-expiratory pressure in obese surgical patients - A sub-study of the PROBESE randomized controlled trial

STUDY OBJECTIVE

We aimed to characterize intra-operative mechanical ventilation with low or high positive end-expiratory pressure (PEEP) and recruitment manoeuvres (RM) regarding intra-tidal recruitment/derecruitment and overdistension using non-linear respiratory mechanics, and mechanical power in obese surgical patients enrolled in the PROBESE trial.

DESIGN

Prospective, two-centre substudy of the international, multicentre, two-arm, randomized-controlled PROBESE trial.

SETTING

Operating rooms of two European University Hospitals.

PATIENTS

Forty-eight adult obese patients undergoing abdominal surgery.

INTERVENTIONS

Intra-operative protective ventilation with either PEEP of 12 cmH2O and repeated RM (HighPEEP+RM) or 4 cmH2O without RM (LowPEEP).

MEASUREMENTS

The index of intra-tidal recruitment/de-recruitment and overdistension (%E2) as well as airway pressure, tidal volume (VT), respiratory rate (RR), resistance, elastance, and mechanical power (MP) were calculated from respiratory signals recorded after anesthesia induction, 1 h thereafter, and end of surgery (EOS).

MAIN RESULTS

Twenty-four patients were analyzed in each group. PEEP was higher (mean ± SD, 11.7 ± 0.4 vs. 3.7 ± 0.6 cmH2O, P < 0.001) and driving pressure lower (12.8 ± 3.5 vs. 21.7 ± 6.8 cmH2O, P < 0.001) during HighPEEP+RM than LowPEEP, while VT and RR did not differ significantly (7.3 ± 0.6 vs. 7.4 ± 0.8 ml∙kg-1, P = 0.835; and 14.6 ± 2.5 vs. 15.7 ± 2.0 min-1, P = 0.150, respectively). %E2 was higher in HighPEEP+RM than in LowPEEP following induction (-3.1 ± 7.2 vs. -12.4 ± 10.2%; P < 0.001) and subsequent timepoints. Total resistance and elastance (13.3 ± 3.8 vs. 17.7 ± 6.8 cmH2O∙l∙s-2, P = 0.009; and 15.7 ± 5.5 vs. 28.5 ± 8.4 cmH2O∙l, P < 0.001, respectively) were lower during HighPEEP+RM than LowPEEP. Additionally, MP was lower in HighPEEP+RM than LowPEEP group (5.0 ± 2.2 vs. 10.4 ± 4.7 J∙min-1, P < 0.001).

CONCLUSIONS

In this sub-cohort of PROBESE, intra-operative ventilation with high PEEP and RM reduced intra-tidal recruitment/de-recruitment as well as driving pressure, elastance, resistance, and mechanical power, as compared with low PEEP.

TRIAL REGISTRATION

The PROBESE study was registered at www.

CLINICALTRIALS

gov, identifier: NCT02148692 (submission for registration on May 23, 2014).

Effect of Mechanical Ventilation Mode Type on Postoperative Pulmonary Complications After Cardiac Surgery: A Randomized Controlled Trial

OBJECTIVES

It is unknown whether there is a difference in pulmonary outcome in different intraoperative ventilation modes for cardiac surgery with cardiopulmonary bypass (CPB). The aim of this trial was to determine whether patients undergoing cardiac surgery with CPB could benefit from intraoperative optimal ventilation mode.

DESIGN

This was a single-center, prospective, randomized controlled trial.

SETTING

The study was conducted at a single-center tertiary-care hospital.

PARTICIPANTS

A total of 1,364 adults undergoing cardiac surgery with CPB participated in this trial.

INTERVENTIONS

Patients were assigned randomly (1:1:1) to receive 1 of 3 ventilation modes: volume-controlled ventilation (VCV), pressure-controlled ventilation (PCV), and pressure-controlled ventilation-volume guaranteed (PCV-VG). All arms of the study received the lung-protective ventilation strategy.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was a composite of postoperative pulmonary complications (PPCs) within the first 7 postoperative days. Pulmonary complications occurred in 168 of 455 patients (36.9%) in the PCV-VG group, 171 (37.6%) in the PCV group, and 182 (40.1%) in the VCV group, respectively. There was no statistical difference in the risk of overall pulmonary complications among groups (p = 0.585). There were no significant differences in the severity grade of PPCs within 7 days, postoperative ventilation duration, intensive care unit stay, postoperative hospital stay, or 30-day postoperative mortality.

CONCLUSIONS

Among patients scheduled for cardiac surgery with CPB, intraoperative ventilation mode type did not affect the risk of postoperative pulmonary complications.

Perioperative Mortality of the COVID-19 Recovered Patient Compared to a Matched Control: A Multicenter Retrospective Cohort Study

BACKGROUND

Surgical procedures performed on patients with recent exposure to COVID-19 infection have been associated with increased mortality risk in previous studies. Accordingly, elective surgery is often delayed after infection. The study aimed to compare 30-day hospital mortality and postoperative complications (acute kidney injury, pulmonary complications) of surgical patients with a previous COVID-19 infection to a matched cohort of patients without known previous COVID-19. The authors hypothesized that COVID-19 exposure would be associated with an increased mortality risk.

METHODS

In this retrospective observational cohort study, patients presenting for elective inpatient surgery across a multicenter cohort of academic and community hospitals from April 2020 to April 2021 who had previously tested positive for COVID-19 were compared to controls who had received at least one previous COVID-19 test but without a known previous COVID-19-positive test. The cases were matched based on anthropometric data, institution, and comorbidities. Further, the outcomes were analyzed stratified by timing of a positive test result in relation to surgery.

RESULTS

Thirty-day mortality occurred in 229 of 4,951 (4.6%) COVID-19-exposed patients and 122 of 4,951 (2.5%) controls. Acute kidney injury was observed in 172 of 1,814 (9.5%) exposed patients and 156 of 1,814 (8.6%) controls. Pulmonary complications were observed in 237 of 1,637 (14%) exposed patients and 164 of 1,637 (10%) controls. COVID-19 exposure was associated with an increased 30-day mortality risk (adjusted odds ratio, 1.63; 95% CI, 1.38 to 1.91) and an increased risk of pulmonary complications (1.60; 1.36 to 1.88), but was not associated with an increased risk of acute kidney injury (1.03; 0.87 to 1.22). Surgery within 2 weeks of infection was associated with a significantly increased risk of mortality and pulmonary complications, but that effect was nonsignificant after 2 weeks.

CONCLUSIONS

Patients with a positive test for COVID-19 before elective surgery early in the pandemic have an elevated risk of perioperative mortality and pulmonary complications but not acute kidney injury as compared to matched controls. The span of time from positive test to time of surgery affected the mortality and pulmonary risk, which subsided after 2 weeks.

EDITOR’S PERSPECTIVE

Predictors of Failure to Rescue After Postoperative Respiratory Failure: A Retrospective Cohort Analysis of 13,047 Patients Using the ACS-NSQIP Dataset

INTRODUCTION

Death after suffering a postoperative complication (failure to rescue) is an area of concern, and its occurrence after postoperative respiratory failure (PRF) is not well defined. We seek to identify the predictors of failure to rescue in patients who develop PRF.

METHODS

A retrospective cohort study of adults undergoing noncardiac surgery who developed PRF (postoperative unplanned intubation and receipt of mechanical ventilation for longer than 48 h) was conducted using the American College of Surgeons National Surgical Quality Improvement Project database. Predictors of failure to rescue after PRF were identified using the Least Absolute Shrinkage and Selection Operator (LASSO)-penalized variable selection method, with the Bayesian information criterion, in the context of a multiple logistic regression model (with Firth's bias correction).

RESULTS

Of the 13,047 patients that formed our final evaluable study cohort, 3669 (28.1%) patients died within 30 days of surgery. We identified age, sex, American Society of Anesthesiologists physical status, presence of preoperative ascites, disseminated cancer, bleeding disorders, elevated preoperative creatinine, and low preoperative prealbumin levels as predictors of failure to rescue. The area under the curve for the final model was 0.6804, with a standard error of 0.0104 (95% CI area under the curve: 0.6600 to 0.7008).

CONCLUSIONS

We observed that almost 30% of patients that develop respiratory failure after noncardiac surgery die within 30 days of surgery. The validated eight-variable perioperative predictive model provides a risk estimate for death after PRF and may be useful for the purposes of preoperative planning, prognostication, decision making and resource allocation in patients who develop this complication.

Impact of functional status on 30-day resource utilization and organ system complications following index bariatric surgery: a cohort study

BACKGROUND

Bariatric surgical procedures carry an appreciable risk profile despite their elective nature. Identified risk factors for procedural complications are often limited to medical comorbidities. This study assesses the impact of functional status on resource utilization and organ system complications following bariatric surgery.

MATERIALS AND METHODS

This retrospective cohort study analyzed patients undergoing elective, index bariatric surgery from American College of Surgeons National Surgical Quality Improvement Program participating hospitals from 2015 to 2019 ( n =65 627). The primary independent variable was functional status. The primary outcome was unplanned resource utilization. Secondary outcomes included composite organ system complications and mortality. The impact of functional status was first investigated with univariate analyses. Survival and multivariate analyses were then performed on select complications with clinically and statistically significant incidence in the dependent cohort.

RESULTS

On univariate analysis, dependent functional status was associated with unplanned resource utilization [12.1% (27/223) vs. 4.1% (2661/65 404)]; relative risk, 2.98 (95% CI, 2.09-4.25); P < 0.001] and haematologic/infectious complications [6.7% (15/223) vs. 2.4% (1540/65 404); relative risk, 2.86 (95% CI, 1.75-4.67); P < 0.001]. Survival analysis demonstrated a significantly shorter time to both events in patients with dependent functional status ( P < 0.001). On multivariate analysis, dependent functional status was an independent predictor of unplanned resource utilization[adjusted odds ratio 2.17 (95% CI, 1.27-3.50); P = 0.003; model c-statistic, 0.572]) and haematologic/infectious complications [adjusted odds ratio, 2.20 ([95% CI, 1.14-3.86); P = 0.011; model c-statistic, 0.579].

CONCLUSION

Patients with dependent functional status are at an elevated risk of unplanned resource utilization and haematologic/infectious complications following index bariatric surgery. The increased risk cannot be explained by medical comorbidities alone.

Personalized Noninvasive Respiratory Support in the Perioperative Setting: State of the Art and Future Perspectives

Background: Noninvasive respiratory support (NRS), including high-flow nasal oxygen therapy (HFNOT), noninvasive ventilation (NIV) and continuous positive airway pressure (CPAP), are routinely used in the perioperative period. Objectives: This narrative review provides an overview on the perioperative use of NRS. Preoperative, intraoperative, and postoperative respiratory support is discussed, along with potential future areas of research. Results: During induction of anesthesia, in selected patients at high risk of difficult intubation, NIV is associated with improved gas exchange and reduced risk of postoperative respiratory complications. HFNOT demonstrated an improvement in oxygenation. Evidence on the intraoperative use of NRS is limited. Compared with conventional oxygenation, HFNOT is associated with a reduced risk of hypoxemia during procedural sedation, and recent data indicate a possible role for HFNOT for intraoperative apneic oxygenation in specific surgical contexts. After extubation, "preemptive" NIV and HFNOT in unselected cohorts do not affect clinical outcome. Postoperative "curative" NIV in high-risk patients and among those exhibiting signs of respiratory failure can reduce reintubation rate, especially after abdominal surgery. Data on postoperative "curative" HFNOT are limited. Conclusions: There is increasing evidence on the perioperative use of NRS. Use of NRS should be tailored based on the patient's specific characteristics and type of surgery, aimed at a personalized cost-effective approach.

Safety and Feasibility of Intraoperative High PEEP Titrated to the Lowest Driving Pressure (ΔP)-Interim Analysis of DESIGNATION

Uncertainty remains about the best level of intraoperative positive end-expiratory pressure (PEEP). An ongoing RCT ('DESIGNATION') compares an 'individualized high PEEP' strategy ('iPEEP')-titrated to the lowest driving pressure (ΔP) with recruitment maneuvers (RM), with a 'standard low PEEP' strategy ('low PEEP')-using 5 cm H2O without RMs with respect to the incidence of postoperative pulmonary complications. This report is an interim analysis of safety and feasibility. From September 2018 to July 2022, we enrolled 743 patients. Data of 698 patients were available for this analysis. Hypotension occurred more often in 'iPEEP' vs. 'low PEEP' (54.7 vs. 44.1%; RR, 1.24 (95% CI 1.07 to 1.44); p < 0.01). Investigators were compliant with the study protocol 285/344 patients (82.8%) in 'iPEEP', and 345/354 patients (97.5%) in 'low PEEP' (p < 0.01). Most frequent protocol violation was missing the final RM at the end of anesthesia before extubation; PEEP titration was performed in 99.4 vs. 0%; PEEP was set correctly in 89.8 vs. 98.9%. Compared to 'low PEEP', the 'iPEEP' group was ventilated with higher PEEP (10.0 (8.0-12.0) vs. 5.0 (5.0-5.0) cm H2O; p < 0.01). Thus, in patients undergoing general anesthesia for open abdominal surgery, an individualized high PEEP ventilation strategy is associated with hypotension. The protocol is feasible and results in clear contrast in PEEP. DESIGNATION is expected to finish in late 2023.

Analysis of postoperative pulmonary complications after gastrectomy for gastric cancer: development and validation of a nomogram

Background

Postoperative pulmonary complications (PPCs) are common in gastric cancer patients after gastrectomy. The aim of our study was to investigate the perioperative risk factors and to develop a nomogram to identify patients who are at significant risk of PPCs.

Methods

The clinical data of gastric cancer patients who underwent elective gastrectomy in the First Affiliated Hospital of Nanjing Medical University from 2017 to 2021 were retrospectively collected. All patients were randomly divided into a training and a validation cohort at a ratio of 7:3. Univariate and multivariate analysis were applied to identify the independent risk factors that might predict PPCs, and a nomogram was constructed. Both discrimination and calibration abilities were estimated by the area under a receiver operating characteristic curve (AUC) and calibration curves. The clinical effectiveness of the nomogram was further quantified with the decision curve analysis (DCA).

Results

Of 2,124 included patients, one hundred and fifty patients (7.1%) developed PPCs. Binary logistic analysis showed that age > 65 years, higher total cholesterol level, longer duration of surgery, total gastrectomy, and the dose of oxycodone > 5.5 mg were independent risk factors for the occurrence of PPCs, which were contained in the nomogram. The predictive nomogram showed good discrimination and calibration [an AUC of 0.735 (95% CI: 0.687-0.783) in a training cohort and 0.781 (95% CI: 0.715-0.847) in a validation cohort]. The calibration curve and decision curve analysis showed a good agreement between nomogram predictions and actual observations.

Conclusion

We developed a nomogram model based on age, total cholesterol, extent of resection, duration of surgery, and the dose of oxycodone to predict the risk of PPCs in gastric cancer patients after elective gastrectomy.

Functional capacity in smoking patients after coronary artery bypass grafting surgery: a quasi-experimental study

Coronary artery bypass grafting surgery (CABG) is an important approach to treating coronary heart disease. However, patients undergoing open heart surgery are at risk of postoperative complications. Cigarette smoking is one of the preoperative risk factors that may increase postoperative complications. Studies show that early mobilization intervention may reduce these complications and improve functional capacity, but the impact of smoking on early outcomes after CABG has been controversial for the past two decades. This quasi-experimental study explored the effects of early mobilization on functional capacity among patients with different smoking histories undergoing CABG. The study involved 51 participants who underwent CABG surgery, divided into three groups: current smokers, former smokers, and non-smokers (n=17 each). A day before surgery, all groups underwent a six-minute walking test (6MWT). Every participant received the same intervention after surgery, including deep breathing exercises, an upper limb range of motion assessment, an incentive spirometer, and walking with and without assistance. Five days postoperatively, all outcomes - including the 6MWT, length of stay (LOS) in the ICU, and postoperative pulmonary complications - were assessed, and the 6MWT was repeated. There was a reduced functional capacity after CABG in ex-smokers (215.8±102 m) and current smokers (272.7±97m) compared to non-smokers (298.5±97.1m) in terms of 6MWT (p<0.05). Current smokers were more likely to have atelectasis after CABG than ex-smokers (76.5% vs. 52.9%), with non-smokers being the least likely to have atelectasis among the three groups (29.4%, p<0.05). Additionally, current smokers required longer ventilator support post-CABG (11.9±7.3 hours) compared to ex-smokers (8.3±4.3 hours) and non-smokers (7±2.5 hours, p<0.01). Smoking status significantly impacts functional capacity reduction after CABG, with current smokers being more susceptible to prolonged ventilator use and atelectasis.

A Least Absolute Shrinkage and Selection Operator-Derived Predictive Model for Postoperative Respiratory Failure in a Heterogeneous Adult Elective Surgery Patient Population

BACKGROUND

Postoperative respiratory failure (PRF) is associated with increased hospital charges and worse patient outcomes. Reliable prediction models can help to guide postoperative planning to optimize care, to guide resource allocation, and to foster shared decision-making with patients.

RESEARCH QUESTION

Can a predictive model be developed to accurately identify patients at high risk of PRF?

STUDY DESIGN AND METHODS

In this single-site proof-of-concept study, we used structured query language to extract, transform, and load electronic health record data from 23,999 consecutive adult patients admitted for elective surgery (2014-2021). Our primary outcome was PRF, defined as mechanical ventilation after surgery of > 48 h. Predictors of interest included demographics, comorbidities, and intraoperative factors. We used logistic regression to build a predictive model and the least absolute shrinkage and selection operator procedure to select variables and to estimate model coefficients. We evaluated model performance using optimism-corrected area under the receiver operating curve and area under the precision-recall curve and calculated sensitivity, specificity, positive and negative predictive values, and Brier scores.

RESULTS

Two hundred twenty-five patients (0.94%) demonstrated PRF. The 18-variable predictive model included: operations on the cardiovascular, nervous, digestive, urinary, or musculoskeletal system; surgical specialty orthopedic (nonspine); Medicare or Medicaid (as the primary payer); race unknown; American Society of Anesthesiologists class ≥ III; BMI of 30 to 34.9 kg/m2; anesthesia duration (per hour); net fluid at end of the operation (per liter); median intraoperative FIO2, end title CO2, heart rate, and tidal volume; and intraoperative vasopressor medications. The optimism-corrected area under the receiver operating curve was 0.835 (95% CI,0.808-0.862) and the area under the precision-recall curve was 0.156 (95% CI, 0.105-0.203).

INTERPRETATION

This single-center proof-of-concept study demonstrated that a structured query language extract, transform, and load process, based on readily available patient and intraoperative variables, can be used to develop a prediction model for PRF. This PRF prediction model is scalable for multicenter research. Clinical applications include decision support to guide postoperative level of care admission and treatment decisions.

Pulmonary Complications and Mortality in Patients with SARS-CoV-2 Undergoing Elective and Emergent Hand Surgery

Background  Patients acutely infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may have increased risk for postsurgical pulmonary complications and mortality, particularly with general anesthesia. Surgery is often delayed to mitigate risk; however, excessive delays may result in morbidity. Optimal criteria for delaying surgery in patients with or without symptoms are unknown. This study aimed to evaluate any complications following hand surgery in patients testing positive for SARS-CoV-2. Methods  We retrospectively reviewed patients with a positive polymerase chain reaction test within 60 days before or after hand surgery between March 31, 2020 and March 31, 2021. Patients were telephoned also to supplement records. Type of surgery, type of anesthesia, comorbidities, timing of surgery, onset of symptoms, and complications were recorded. Results  We identified 21 patients undergoing 26 procedures, of which 21 (81%) were emergency procedures and 5 (19%) were elective. Mean age was 37 years (range: 17-71). General anesthesia was used in 88% of cases, with mean duration of 110 minutes. SARS-CoV-2 was diagnosed on average 6 days preoperatively (range: 39 days preop-14 days postop). Positive tests were usually identified preoperatively (50%), versus day-of-surgery (25%) or postoperatively (25%). Patients were symptomatic in only 27% of cases, and completely asymptomatic in 73%. No asymptomatic patients developed complications. One patient suffered a fracture malunion after delayed surgery. Pulmonary complications were noted in 3 patients; all had prior pulmonary disease and underwent emergency surgeries under general anesthesia. Overall mortality rate was 0%. Conclusion  Pulmonary complications and mortality are low following hand surgery in asymptomatic patients with a positive SARS-CoV-2 test.

Effects of midline laparotomy on cough strength: a prospective study measuring cough pressure

BACKGROUND

Laparotomy is assumed to decrease cough strength due to three factors: abdominal muscle trauma, postoperative pain, and diaphragmatic dysfunction. However, the effect of trauma from laparotomy itself on strength (net of the other two factors) has not been measured to our knowledge. The aim of this study was to measure the effect of laparotomy on cough strength after first measuring the effect of epidural analgesia.

METHODS

In 11 patients scheduled for open midline laparotomy, cough pressure (PCOUGH), a proxy for strength, was measured with a rectal balloon at three moments: before the procedure, at baseline; before surgery, under epidural bupivacaine to T6; and postoperatively, under epidural bupivacaine to the same analgesic level (T6). Continuous variables were compared using the Wilcoxon signed-rank test. The repeatability of PCOUGH measurements was confirmed with the intraclass correlation coefficient (ICC). Pain on coughing, hand grip strength, and the Ramsay and modified Bromage scores were also recorded.

RESULTS

Median (interquartile range) PCOUGH decreased from a baseline of 103 (89-137) to 71 (56-116) cmH2O under presurgical epidural bupivacaine (P=0.003). Postoperative PCOUGH remained unchanged at 76 (46-85) cmH2O under epidural analgesia (P=0.131). The ICCs indicated excellent repeatability of the PCOUGH measurements (P<0.001). Pain on coughing was 0 to 1 in all subjects. Hand grip strength and the Ramsay and Bromage scores were unchanged.

CONCLUSIONS

Although thoracic epidural bupivacaine reduces cough strength as measured by PCOUGH, midline laparotomy does not further reduce strength in the presence of adequate epidural analgesia.

Concordance between ARISCAT risk score and cardiopulmonary exercise test values in risk prediction of postoperative pulmonary complications of major abdominal surgeries in a tertiary cancer hospital: A cross-sectional study

Background and Aims

Pulmonary complications are common after surgery. They include vascular thrombosis, pneumonia, respiratory failure (RF), and pain-related atelectasis. There are a number of models to predict the risk of postoperative respiratory events other than thrombosis. The aim of this study was to explore the correlation of assess respiratory risk in surgical patients in Catalonia (ARISCAT) scoring and cardiopulmonary exercise test (CPET) values in prediction of postoperative pulmonary complications (PPCs).

Methods

Cancer patients referred to a tertiary hospital for elective major abdominal surgeries were studied. Patients were evaluated by ARISCAT score and then CPET was performed to determine the risk of surgery based on maximal oxygen consumption (VO2) value. Patients were followed for RF occurrence up to 72 h after surgery. Finally, the concordance of ARISCAT score and CPET values was evaluated in risk prediction of PPCs.

Results

The results showed that parameters VO2, ARISCAT score, and anaerobic threshold could predict postoperative RF. Of these parameters, ARISCAT showed the highest sensitivity (100%) and the highest specificity (90.5%) compared with other parameters (Youden's J statistic = 0.905). However, VO2 value showed the highest validity. The percentage of agreement between different subgroups (low, medium, and high) of both criteria (VO2 and ARISCAT) was equal to 81.45% (p < 0.001) and the ϰ coefficient of the given weight was equal to 0.54 (p < 0.001), indicating a good agreement between these two criteria.

Conclusion

ARISCAT scoring showed high sensitivity and specificity to PPCs in cancer patients and good correlation with CPET value for prediction of PPCs. Therefore, it is a reliable and robust risk prediction tool in major abdominal surgeries on cancer patients.

Protective effect of sevoflurane on lung function of elderly chronic obstructive pulmonary disease patients undergoing total hip arthroplasty

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a common respiratory disorder that affects the elderly population and increases the risk of postoperative pulmonary complications (PPCs) after major surgeries. Sevoflurane is a volatile anesthetic that has been shown to have anti-inflammatory and antioxidant properties and attenuate lung injury in animal models.

AIM

To evaluate the protective effect of sevoflurane on the lung function of elderly COPD patients undergoing total hip arthroplasty (THA).

METHODS

In this randomized controlled trial, we randomly assigned 120 elderly patients with COPD, who were scheduled for THA, to receive either sevoflurane (sevoflurane group) or propofol (propofol group) as the maintenance anesthetic. The primary outcome was the incidence of PPCs within seven days after surgery. The secondary outcomes were changes in the lung function parameters, inflammatory markers, oxidative stress markers, and postoperative pain scores.

RESULTS

The results showed that the incidence of PPCs was significantly lower in the sevoflurane group than in the propofol group (10% vs 25%, P = 0.02). Furthermore, the decline in the forced expiratory volume in 1 s, forced vital capacity, and peak expiratory flow was significantly lesser in the sevoflurane group than in the propofol group at 24 h and 48 h after surgery (P < 0.05). The interleukin-6, tumor necrosis factor-alpha, malondialdehyde, and 8-hydroxy-2 α-deoxyguanosine levels were significantly lower in the sevoflurane group than in the propofol group at 24 h after surgery (P < 0.05). The sevoflurane group showed significantly lower postoperative pain scores than the propofol group at 6 h, 12 h, and 24 h after surgery (P < 0.05).

CONCLUSION

Sevoflurane protects the lung function of elderly COPD patients undergoing THA under general anesthesia by reducing the incidence of PPCs, attenuating inflammatory and oxidative stress responses, and alleviating postoperative pain.

Postoperative pulmonary complications and mortality after major abdominal surgery. An observational multicenter prospective study

BACKGROUND

Postoperative pulmonary complications (PPCs) significantly contribute to postoperative morbidity and mortality. We conducted a study to determine the incidence of PPCs after major elective abdominal surgery and their association with early and 1-year mortality in patient without pre-existing respiratory disease.

METHODS

We conducted a multicenter observational prospective clinical study in 40 Italian centers. 1542 patients undergoing elective major abdominal surgery were recruited in a time period of 14 days and clinically managed according to local protocol. The primary outcome was to determine the incidence of PPCs. Further, we aimed to identify independent predictors for PPCs and examine the association between PPCs and mortality.

RESULTS

PPCs occurred in 12.6% (95% CI 11.1-14.4%) of patients with significant differences among general (18.3%, 95% CI 15.7-21.0%), gynecological (3.7%, 95% CI 2.1-6.0%) and urological surgery (9.0%, 95% CI 6.0-12.8%). PPCs development was associated with known pre- and intraoperative risk factors. Patients who developed PPCs had longer length of hospital stay, higher risk of 30-days hospital readmission, and increased in-hospital and one-year mortality (OR 3.078, 95% CI 1.825-5.191; P<0.001).

CONCLUSIONS

The incidence of PPCs in patients without pre-existing respiratory disease undergoing elective abdominal surgery is high and associated with worse clinical outcome at one year after surgery. General surgery is associated with higher incidence of PPCs and mortality compared to gynecological and urological surgery.

Personalized multimodal prehabilitation reduces cardiopulmonary complications after pancreatoduodenectomy: results of a propensity score matching analysis

BACKGROUND

The purpose of prehabilitation is to improve postoperative outcomes by increasing patients' resilience against the stress of surgery. This study investigates the effect of personalized multimodal prehabilitation on patients undergoing pancreatoduodenectomy.

METHODS

Included patients were screened for six modifiable risk factors: (1) low physical fitness, (2) malnutrition, (3) low mental resilience, (4) anemia and hyperglycemia, (5) frailty, and (6) substance abuse. Interventions were performed as needed. Using 1:1 propensity score matching (PSM), patients were compared to a historical cohort.

RESULTS

From 120 patients, 77 (64.2%) performed a cardiopulmonary exercise test to assess their physical fitness and provide them with a preoperative training advice. Furthermore, 88 (73.3%) patients received nutritional support, 15 (12.5%) mental support, 17 (14.2%) iron supplementation to correct for iron deficiency, 18 (15%) regulation support for hyperglycemia, 14 (11.7%) a comprehensive geriatric assessment, and 19 (15.8%) substance abuse support. Of all patients, 63% required ≥2 prehabilitation interventions. Fewer cardiopulmonary complications were observed in the prehabilitation cohort (9.2% versus 23.3%; p = 0.002). In surgical outcomes and length of stay no differences were observed.

CONCLUSION

Our prehabilitation program is effective in detecting risk factors in patients; most patients required multiple interventions. Consequently, a reduction in cardiopulmonary complications was observed.