Predicting postoperative pulmonary complications in the general population. Curr Opin Anaesthesiol. 2013;26:107-115. [PMID: 23407154 DOI: 10.1097/aco.0b013e32835e8acd]

Incidence and risk factors of postoperative pulmonary complications following total hip arthroplasty revision: a retrospective Nationwide Inpatient Sample database study

BACKGROUND

Postoperative pulmonary complications (PPCs) are among the most severe complications following total hip arthroplasty revision (THAR), imposing significant burdens on individuals and society. This study examined the prevalence and risk factors of PPCs following THAR using the NIS database, identifying specific pulmonary complications (SPCs) and their associated risks, including pneumonia, acute respiratory failure (ARF), and pulmonary embolism (PE).

METHODS

The National Inpatient Sample (NIS) database was used for this cross-sectional study. The analysis included patients undergoing THAR based on NIS from 2010 to 2019. Available data include demographic data, diagnostic and procedure codes, total charges, length of stay (LOS), hospital information, insurance information, and discharges.

RESULTS

From the NIS database, a total of 112,735 THAR patients in total were extracted. After THAR surgery, there was a 2.62% overall incidence of PPCs. Patients with PPCs after THAR demonstrated increased LOS, total charges, usage of Medicare, and in-hospital mortality. The following variables have been determined as potential risk factors for PPCs: advanced age, pulmonary circulation disorders, fluid and electrolyte disorders, weight loss, congestive heart failure, metastatic cancer, other neurological disorders (encephalopathy, cerebral edema, multiple sclerosis etc.), coagulopathy, paralysis, chronic pulmonary disease, renal failure, acute heart failure, deep vein thrombosis, acute myocardial infarction, peripheral vascular disease, stroke, continuous trauma ventilation, cardiac arrest, blood transfusion, dislocation of joint, and hemorrhage.

CONCLUSIONS

Our study revealed a 2.62% incidence of PPCs, with pneumonia, ARF, and PE accounting for 1.24%, 1.31%, and 0.41%, respectively. A multitude of risk factors for PPCs were identified, underscoring the importance of preoperative optimization to mitigate PPCs and enhance postoperative outcomes.

Risk factors for postoperative pulmonary complications in elderly patients undergoing video-assisted thoracoscopic surgery lobectomy under general anesthesia: a retrospective study

BACKGROUND

The objective of this study is to identify and evaluate the risk factors associated with the development of postoperative pulmonary complications (PPCs) in elderly patients undergoing video-assisted thoracoscopic surgery lobectomy under general anesthesia.

METHODS

The retrospective study consecutively included elderly patients (≥ 70 years old) who underwent thoracoscopic lobectomy at Xuanwu Hospital of Capital Medical University from January 1, 2018 to August 31, 2023. The demographic characteristics, the preoperative, intraoperative and postoperative parameters were collected and analyzed using multivariate logistic regression to identify the prediction of risk factors for PPCs.

RESULTS

322 patients were included for analysis, and 115 patients (35.7%) developed PPCs. Multifactorial regression analysis showed that ASA ≥ III (P = 0.006, 95% CI: 1.230 ∼ 3.532), duration of one-lung ventilation (P = 0.033, 95% CI: 1.069 ∼ 4.867), smoking (P = 0.027, 95% CI: 1.072 ∼ 3.194) and COPD (P = 0.015, 95% CI: 1.332 ∼ 13.716) are independent risk factors for PPCs after thoracoscopic lobectomy in elderly patients.

CONCLUSION

Risk factors for PPCs are ASA ≥ III, duration of one-lung ventilation, smoking and COPD in elderly patients over 70 years old undergoing thoracoscopic lobectomy. It is necessary to pay special attention to these patients to help optimize the allocation of resources and enhance preventive efforts.

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.

A novel nephrectomy-specific respiratory failure index using the ACS-NSQIP dataset

PURPOSE

Post-operative pulmonary failure is a major complication of nephrectomy that may lead to severe morbidity and mortality. Hence, we aimed to derive a nephrectomy-specific post-operative respiratory failure index.

METHODS

Our cohort was derived from The American College of Surgeons-National Surgical Quality Improvement Program database between 2005 and 2019. The outcome of interest was post-operative respiratory failure (PRF) defined as any incidence of unplanned intubation post-operatively or requiring mechanical ventilation post-operatively for a period > 48 h. A multivariable logistic regression model was constructed, and model calibration and performance were assessed using a ROC analysis and the Hosmer-Lemeshow test. Finally, we derived the nephrectomy-specific respiratory failure (NSRF) index and compared it to Gupta's index.

RESULTS

Seventy-nine thousand five hundred and twenty-three patients underwent nephrectomy between the years 2005 and 2019 of which nine hundred and sixty-two patients developed PRF. The final NSRF model encompassed ten variables: age, smoking status, American society of anesthesiology class, abnormal creatinine (≥ 1.5 mg/dL), anemia (< 36%), functional health status, chronic obstructive pulmonary disease, surgical approach, emergency case, and obesity (≥ 40 kg/m²). The NSRF ROC analysis provided C-statistic = 0.78, calibration R² = 0.99, and proper goodness of fit. In comparison, the C-statistics of Gupta's index was found to be 0.71 (p value < 0.001).

CONCLUSION

The NSRF is a procedure tailored index for predicting post-operative respiratory failure. It is a valuable tool in the pre-operative evaluation setting that can help identify high-risk patients who will require additional respiratory evaluation and preparation for their surgery.

Implementation of ISO/IEEE 11073 PHD SpO2 and ECG Device Specializations over Bluetooth HDP following Health Care Profile for Smart Living

Current m-Health scenarios in the smart living era, as the interpretation of the smart city at each person’s level, present several challenges associated with interoperability between different clinical devices and applications. The Continua Health Alliance establishes design guidelines to standardize application communication to guarantee interoperability among medical devices. In this paper, we describe the implementation of two IEEE agents for oxygen saturation level (SpO2) measurements and electrocardiogram (ECG) data acquisition, respectively, and a smartphone IEEE manager for validation. We developed both IEEE agents over the Bluetooth Health Device Profile following the Continua guidelines and they are part of a telemonitoring system. This system was evaluated in a sample composed of 10 volunteers (mean age 29.8 ± 7.1 y/o; 5 females) under supervision of an expert cardiologist. The evaluation consisted of measuring the SpO2 and ECG signal sitting and at rest, before and after exercising for 15 min. Physiological measurements were assessed and compared against commercial devices, and our expert physician did not find any relevant differences in the ECG signal. Additionally, the system was assessed when acquiring and processing different heart rate data to prove that warnings were generated when the heart rate was under/above the thresholds for bradycardia and tachycardia, respectively.

Clinical guide to perioperative management for videothoracoscopy lung resection (Section of Cardiac, Vascular and Thoracic Anesthesia, SEDAR; Spanish Society of Thoracic Surgery, SECT; Spanish Society of Physiotherapy)

The introduction of video-assisted thoracoscopic (VATS) techniques has led to a new approach in thoracic surgery. VATS is performed by inserting a thoracoscope through a small incisions in the chest wall, thus maximizing the preservation of muscle and tissue. Because of its low rate of morbidity and mortality, VATS is currently the technique of choice in most thoracic procedures. Lung resection by VATS reduces prolonged air leaks, arrhythmia, pneumonia, postoperative pain and inflammatory markers. This reduction in postoperative complications shortens hospital length of stay, and is particularly beneficial in high-risk patients with low tolerance to thoracotomy. Compared with conventional thoracotomy, the oncological results of VATS surgery are similar or even superior to those of open surgery. This aim of this multidisciplinary position statement produced by the thoracic surgery working group of the Spanish Society of Anesthesiology and Reanimation (SEDAR), the Spanish Society of Thoracic Surgery (SECT), and the Spanish Association of Physiotherapy (AEF) is to standardize and disseminate a series of perioperative anaesthesia management guidelines for patients undergoing VATS lung resection surgery. Each recommendation is based on an in-depth review of the available literature by the authors. In this document, the care of patients undergoing VATS surgery is organized in sections, starting with the surgical approach, and followed by the three pillars of anaesthesia management: preoperative, intraoperative, and postoperative anaesthesia.

Clinical guide to perioperative management for videothoracoscopy lung resection (Section of Cardiac, Vascular and Thoracic Anesthesia, SEDAR; Spanish Society of Thoracic Surgery, SECT; Spanish Society of Physiotherapy)

The introduction of video-assisted thoracoscopic (VATS) techniques has led to a new approach in thoracic surgery. VATS is performed by inserting a thoracoscope through a small incisions in the chest wall, thus maximizing the preservation of muscle and tissue. Because of its low rate of morbidity and mortality, VATS is currently the technique of choice in most thoracic procedures. Lung resection by VATS reduces prolonged air leaks, arrhythmia, pneumonia, postoperative pain and inflammatory markers. This reduction in postoperative complications shortens hospital length of stay, and is particularly beneficial in high-risk patients with low tolerance to thoracotomy. Compared with conventional thoracotomy, the oncological results of VATS surgery are similar or even superior to those of open surgery. This aim of this multidisciplinary position statement produced by the thoracic surgery working group of the Spanish Society of Anesthesiology and Reanimation (SEDAR), the Spanish Society of Thoracic Surgery (SECT), and the Spanish Association of Physiotherapy (AEF) is to standardize and disseminate a series of perioperative anaesthesia management guidelines for patients undergoing VATS lung resection surgery. Each recommendation is based on an in-depth review of the available literature by the authors. In this document, the care of patients undergoing VATS surgery is organized in sections, starting with the surgical approach, and followed by the three pillars of anaesthesia management: preoperative, intraoperative, and postoperative anaesthesia.

Predicting Pulmonary Complications Following Upper and Lower Abdominal Surgery: ASA vs. ARISCAT Risk Index

Objective

Postoperative pulmonary complications (POPC) account for a substantial proportion of risk related to surgery and anaesthesia. The American Society of Anesthesiologists (ASA) classification and the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) risk index correlate well with POPC. Here, we compared their accuracy in predicting pulmonary complications following upper and lower abdominal surgery.

Methods

We retrospectively reviewed the medical records of patients undergoing upper and lower abdominal surgery. We collected patients’ demographic data, comorbidities, preoperative pulmonary risk score, laboratory results, surgical data, respiratory tract infection history within one month before surgery, surgical urgency, ASA scores and pulmonary complications within one month after the surgery.

Results

We evaluated 241 patients [upper abdominal surgery (UAS) n=121; lower abdominal surgery (LAS) n=120; mean age 55.7±3.1 years]. In the UAS, 55.8% of the patients were male. In LAS, all patients were female. In both groups, the most common POPC was pleural effusion with compressive atelectasis (CA). Regarding risk score, in both groups, patients with high-risk developed a higher rate of pulmonary complications [UAS (50%), LAS (40%)]. In patients with low-risk scores, the rate of pulmonary complications was significantly lower than the intermediate and high-risk groups (p<0.001). A positive correlation was observed between preoperative risk score and complications (UAS r=0.34; LAS r=0.35 p<0.05). No association was observed between the ASA scores and POPC (p=0.8).

Conclusion

The ASA classification was found to be a weaker modality than ARİSCAT risk index to predict pulmonary complications after the upper and lower abdominal surgeries.

How to optimize critical care resources in surgical patients: intensive care without physical borders

PURPOSE OF REVIEW

Timely identification of surgery patients at risk of postoperative complications is important to improve the care process, including critical care. This review discusses epidemiology and impact of postoperative complications; prediction scores used to identify surgical patients at risk of complications, and the role of critical care in the postoperative management. It also discusses how critical care may change, with respect to admission to the ICU.

RECENT FINDING

Optimization of postoperative outcome, next to preoperative and intraoperative optimization, consists of using risk scores to early identify patients at risk of developing complications. Critical care consultancy should be performed in the ward after surgery, if necessary. ICUs could work at different levels of intensity, but remain preferably multidisciplinary, combining care for surgical and medical patients. ICU admission should still be considered for those patients at very high risk of postoperative complications, and for those receiving complex or emergency interventions.

SUMMARY

To optimize critical care resources for surgery patients at high risk of postoperative complications, the care process should not only include critical care and monitoring in ICUs, but also strict monitoring in the ward. Prediction scores could help to timely identify patients at risk. More intense care (monitoring) outside the ICU could improve outcome. This concept of critical care without borders could be implemented in the near future to optimize the local resources and improve patient safety. Predict more, do less in ICUs, and more in the ward.

Risk factors and cancer recurrence associated with postoperative complications after thoracoscopic lobectomy for clinical stage I non-small cell lung cancer

Background

Minimally invasive thoracoscopic lobectomy is the recommended surgery for clinical stage I non‐small cell lung cancer (NSCLC). The purpose of this study was to identify the risk factors, including sarcopenia, for postoperative complications in patients undergoing a complete single‐lobe thoracoscopic lobectomy for clinical stage I NSCLC, as well as the impact of complications on disease‐free survival.

Methods

We retrospectively investigated 173 patients with pathologically‐diagnosed NSCLC who underwent curative thoracoscopic lobectomies between April 2013 and March 2018. Sarcopenia was assessed using the psoas muscle index calculated from preoperative computed tomography images at the third lumbar vertebral level.

Results

Complications developed in 38 (22%) patients, including 21 with prolonged air leak. In univariate analysis, the significant risk factors for complications were advanced age, male sex, higher Charlson Comorbidity Index (CCI) score, lower cholinesterase, lower albumin, higher creatinine level, pleural adhesion, operative time ≥ five hours, nonadenocarcinoma cancer, and larger tumor size. Multivariate analysis showed that age ≥ 75 years (P = 0.002) and pleural adhesion (P = 0.026) were significant independent risk factors for complications. Compared with the patient group without complications, postoperative complications were independently associated with shorter disease‐free survival (P = 0.01).

Conclusions

Advanced age and pleural adhesion were independent risk factors for complications after complete single‐lobe thoracoscopic lobectomies for clinical stage I NSCLC, and postoperative complications were statistically associated with poor prognosis. Surgical teams should ensure an experienced surgeon leads the operation for patients at higher risk to avoid prolonged postoperative hospitalization and a possible poor prognosis.

Oxygenation Impairment during Anesthesia

Editor’s Perspective

What We Already Know about This Topic

What This Article Tells Us That Is New

Background

Anesthesia is increasingly common in elderly and overweight patients and prompted the current study to explore mechanisms of age- and weight-dependent worsening of arterial oxygen tension (Pao2).

Methods

This is a primary analysis of pooled data in patients with (1) American Society of Anesthesiologists (ASA) classification of 1; (2) normal forced vital capacity; (3) preoxygenation with an inspired oxygen fraction (Fio2) more than 0.8 and ventilated with Fio2 0.3 to 0.4; (4) measurements done during anesthesia before surgery. Eighty patients (21 women and 59 men, aged 19 to 69 yr, body mass index up to 30 kg/m2) were studied with multiple inert gas elimination technique to assess shunt and perfusion of poorly ventilated regions (low ventilation/perfusion ratio []) and computed tomography to assess atelectasis.

Results

Pao2/Fio2 was lower during anesthesia than awake (368; 291 to 470 [median; quartiles] vs. 441; 397 to 462 mm Hg; P = 0.003) and fell with increasing age and body mass index. Log shunt was best related to a quadratic function of age with largest shunt at 45 yr (r2 =0.17, P = 0.001). Log shunt was linearly related to body mass index (r2 = 0.15, P &lt; 0.001). A multiple regression analysis including age, age2, and body mass index strengthened the association further (r2 = 0.27). Shunt was highly associated to atelectasis (r2 = 0.58, P &lt; 0.001). Log low showed a linear relation to age (r2 = 0.14, P = 0.001).

Conclusions

Pao2/Fio2 ratio was impaired during anesthesia, and the impairment increased with age and body mass index. Shunt was related to atelectasis and was a more important cause of oxygenation impairment in middle-aged patients, whereas low, likely caused by airway closure, was more important in elderly patients. Shunt but not low increased with increasing body mass index. Thus, increasing age and body mass index impaired gas exchange by different mechanisms during anesthesia.

Anesthetics to Prevent Lung Injury in Cardiac Surgery (APLICS): a protocol for a randomized controlled trial

Background

Patients undergoing cardiac surgery with cardiopulmonary bypass are at an increased risk of developing postoperative pulmonary complications, potentially leading to excess morbidity and mortality. It is likely that pulmonary ischemia-reperfusion (IR) injury during cardiopulmonary bypass is a major contributor to perioperative lung injury. Therefore, interventions that can minimize IR injury would be valuable in reducing the excess burden of this potentially preventable disease process. Volatile anesthetics including sevoflurane have been shown in both preclinical and human trials to effectively limit pulmonary inflammation in a number of settings including ischemia-reperfusion injury. However, this finding has not yet been demonstrated in the cardiac surgery population. The Anesthetics to Prevent Lung Injury in Cardiac Surgery (APLICS) trial is a randomized controlled trial (RCT) investigating whether sevoflurane anesthetic maintenance can modulate pulmonary inflammation occurring during cardiac surgery with cardiopulmonary bypass and whether this potential effect can translate to a reduction in postoperative pulmonary complications.

Methods

APLICS is a prospective RCT of adult cardiac surgical patients. Participants will be randomized to receive intraoperative anesthetic maintenance with either sevoflurane or propofol. Patients in both groups will be ventilated according to protocols intended to minimize the influences of ventilator-induced lung injury and hyperoxia. Bronchoalveolar lavage (BAL) and blood sampling will take place after anesthetic induction and 2–4 h after pulmonary reperfusion. The primary outcome is a difference between groups in the degree of post-bypass lung inflammation, defined by BAL concentrations of TNFα. Secondary outcomes will include differences in additional relevant BAL and systemic inflammatory markers and the incidence of postoperative pulmonary complications.

Discussion

APLICS investigates whether anesthetic choice can influence lung inflammation and pulmonary outcomes following cardiac surgery with cardiopulmonary bypass. A positive result from this trial would add to the growing body of evidence describing the lung protective properties of the volatile anesthetics and potentially reduce unnecessary morbidity for cardiac surgery patients.

Trial registration

ClinicalTrials.gov, NCT02918877. Registered on 29 September 2016.

Electronic supplementary material

The online version of this article (10.1186/s13063-019-3400-x) contains supplementary material, which is available to authorized users.

Negative pressure pulmonary edema postextubation following medial nerve repair with sural graft surgery in a young patient: A case report

RATIONALE

Negative pressure pulmonary edema (NPPE) is a serious well-described pulmonary complication. It occurs after an intense inspiratory effort against an obstructed or closed upper airway and generates a large negative airway pressure, leading to severe pulmonary edema (transvascular fluid filtration and interstitial/alveolar edema) and hypoxemia. We present a case of NPPE following general anesthesia in a patient who underwent median nerve neurorrhaphy with graft from lower left limb (sural nerve) due to sharp injury.

PATIENT CONCERNS

A 39-year-old Hispanic male was admitted to the Hospital Universitario de San José and scheduled to undergo a median nerve neurorrhaphy under general anesthesia. Preoperative vital signs, physical examination, and laboratory assessments were unremarkable. At the end of surgery, anesthetic agents were ceased after patient responded to commands and maintained eye contact. However, immediately after extubation, anesthesia care providers observed marked respiratory distress and rapid development of hypoxia.

DIAGNOSES

After extubation, patient presented multiple episodes of hemoptysis, tachypnea (25 per minute), blood oxygen saturation (SpO2) of 82% and abundant bilateral pulmonary rales. A baseline chest x-ray revealed symmetric parenchymal opacities with ground-glass attenuation and bilateral multilobar consolidations patterns. The diagnosis of NPPE was established and supportive treatment was initiated.

INTERVENTIONS

The patient received noninvasive mechanical ventilation with a PEEP at 10 cmH2O, intravenous furosemide (20 mg.) every 12 hours, and fluids restriction. Patient remained in PACU for continuing monitoring and laboratory/imaging follow-up testing until next morning.

OUTCOMES

On postoperative day 1, patient responded satisfactorily to supportive treatment and transferred to the general care floor; oxygen supplementation was discontinued 12 hours after extubation time. On postoperative day 3, after the evaluation of a chest x-ray, patient was discharged to home in stable conditions LESSON:: The occurrence of NPPE in the perioperative setting could be successfully managed with supportive regimens, effective clinical team coordination, and awareness of the importance of its rapid diagnosis.

Kasai procedure improves nutritional status and decreases transplantation-associated complications

BACKGROUND

The aim of this study was to retrospectively investigate whether Kasai Procedure (KP) improves nutritional status and whether KP decreases liver transplantation (LT)-associated complications in children with biliary atresia (BA).

METHODS

From March 1st 2014 to February 28th 2015, 103 patients underwent LT and the other 17 without prior KP died during the waiting period. In 103 patients undergoing LT, 58 patients received KP previously (Group A), and 45 only underwent primary LT (Group B). The nutritional status, liver function and LT-related short-term complications were analyzed.

RESULTS

Compared to Group B, patients in Group A had significantly increased time interval when undergoing LT (p < 0.05). Persistently, the bodyweight, albumin and hemoglobin in Group A were significantly increased compared to Group B (all, p < 0.0001). The bilirubin, ALT/AST and PELD score in Group A were all decreased compared to Group B (p < 0.05) prior to LT. The incidences of post-LT severe infection and hypoalbuminemia in Group A were significantly lower than those of Group B (p < 0.05).

CONCLUSIONS

KP improves the nutritional status, preserves liver function for patients who finally undergo LT, and decreases the incidence post-LT severe infection and hypoalbuminemia. Mental health can be improved in parents whose children underwent previous KP.

Associations between intraoperative ventilator settings during one-lung ventilation and postoperative pulmonary complications: a prospective observational study

Background

The interest in perioperative lung protective ventilation has been increasing. However, optimal management during one-lung ventilation (OLV) remains undetermined, which not only includes tidal volume (V_T) and positive end-expiratory pressure (PEEP) but also inspired oxygen fraction (F_IO₂). We aimed to investigate current practice of intraoperative ventilation during OLV, and analyze whether the intraoperative ventilator settings are associated with postoperative pulmonary complications (PPCs) after thoracic surgery.

Methods

We performed a prospective observational two-center study in Japan. Patients scheduled for thoracic surgery with OLV from April to October 2014 were eligible. We recorded ventilator settings (F_IO₂, V_T, driving pressure (ΔP), and PEEP) and calculated the time-weighted average (TWA) of ventilator settings for the first 2 h of OLV. PPCs occurring within 7 days of thoracotomy were investigated. Associations between ventilator settings and the incidence of PPCs were examined by multivariate logistic regression.

Results

We analyzed perioperative information, including preoperative characteristics, ventilator settings, and details of surgery and anesthesia in 197 patients. Pressure control ventilation was utilized in most cases (92%). As an initial setting for OLV, an F_IO₂ of 1.0 was selected for more than 60% of all patients. Throughout OLV, the median TWA F_IO₂ of 0.8 (0.65-0.94), V_T of 6.1 (5.3-7.0) ml/kg, ΔP of 17 (15-20) cm H₂O, and PEEP of 4 (4-5) cm H₂O was applied. Incidence rate of PPCs was 25.9%, and F_IO₂ was independently associated with the occurrence of PPCs in multivariate logistic regression. The adjusted odds ratio per F_IO₂ increase of 0.1 was 1.30 (95% confidence interval: 1.04-1.65, P = 0.0195).

Conclusions

High F_IO₂ was applied to the majority of patients during OLV, whereas low V_T and slight degree of PEEP were commonly used in our survey. Our findings suggested that a higher F_IO₂ during OLV could be associated with increased incidence of PPCs.

Electronic supplementary material

The online version of this article (10.1186/s12871-018-0476-x) contains supplementary material, which is available to authorized users.

Effects of remifentanil on pharyngeal swallowing: A double blind randomised cross-over study in healthy volunteers

BACKGROUND

Exposure to remifentanil increases the incidence of pulmonary aspiration in healthy volunteers. This effect may be explained by impairment of airway defence mechanisms and/or altered swallowing function. Pressure-flow analysis is a technique that allows objective assessment of swallowing based on pressure-impedance patterns recorded during bolus swallowing.

OBJECTIVES

The aim of this study was to use pressure-flow analysis to quantify the effect of remifentanil on healthy pharyngeal swallowing and to compare these effects with morphine.

DESIGN

A double-blind, randomised, cross-over study.

SETTING

A tertiary care teaching hospital.

VOLUNTEERS

Eleven young volunteers (mean age, 23 years) and seven older volunteers (mean age, 73 years).

INTERVENTIONS

Volunteers were studied twice and received either a target-controlled remifentanil infusion (target concentrations: young, 3 ng ml; old, 2 ng ml) or a bolus injection of morphine (dose: young, 0.1 mg kg; old, 0.07 mg kg). Pharyngeal pressure and impedance were recorded with an indwelling catheter while swallowing 10 boluses of liquid during each measuring phase. Variables defining swallowing function were calculated and compared to determine drug effects.

MAIN OUTCOME MEASURES

Pharyngeal pressure-flow variables following remifentanil exposure.

RESULTS

Changes produced by remifentanil in the measured variables were consistent with greater dysfunction of swallowing. Both the strength of the pharyngeal contractions and pharyngeal bolus propulsion were reduced, whereas flow resistance was increased. The swallow risk index, a global index of swallowing dysfunction, increased overall. At the experimental doses tested, morphine produced similar, but less extensive effects on swallowing.

CONCLUSION

Remifentanil induced dysfunction of the pharyngeal swallowing mechanism. This may contribute to an increased risk of aspiration.

TRIAL REGISTRATION

NCT01924234 (www.clinicaltrials.gov).

The long-term impact of postoperative pulmonary complications after video-assisted thoracic surgery lobectomy for lung cancer

Background

Pulmonary complications (PCs) may influence long-term survivor. We sought to determine the long-term impacts of major pulmonary complications (MPCs) and identify the independent risk factors in non-small cell lung cancer (NSCLC) patients.

Methods

A retrospective study was conducted to analyze the PCs of 828 NSCLC patients who underwent video-assisted thoracic surgery (VATS) lobectomy in Peking University Hospital, the complications were graded according to TMM classification. The effects of PCs on the long-term prognosis were analyzed by using the Kaplan-Meier method. Multivariate logistic regression analysis was used to determine the risk factors of MPCs.

Results

Of 828 patients, 139 had PCs, including 66 (8%) MPCs, those patients who developed a PC had longer drainage time, hospital stay and higher perioperative mortality rate. Excluding perioperative deaths, those who develop a MPC had a reduced 3-year disease-free survival (DFS) and 5-year DFS (68.2% vs. 78.7%, 44.7% vs. 70.3%; P=0.001), as well as the reduced 3-year overall survival (OS) and 5-year OS (81.8% vs. 88.6%, 66.6% vs. 80.9%; P=0.023). MPCs were independent prognostic factors of patients with lung cancer. Multivariate logistic regression analysis showed that the independent risk factors for MPCs were age [P=0.007; hazard ratio (HR): 1.05, 95% confidence interval (CI): 1.01-1.08], male (P=0.001; HR: 3.33, 95% CI: 1.87-5.94) and American Society of Anesthesiologist (ASA) grade.

Conclusions

MPC after VATS lobectomy is associated with a poorer long-time outcome. The independent risk factors for MPCs were age, male and ASA grade.

Pulmonary Complications After Open Abdominal Aortic Surgery: A Systematic Review and Meta-Analysis

OBJECTIVES

Postoperative pulmonary complications (PPC) are among the most common complications after noncardiac surgery. Men, smokers, and elderly patients with chronic obstructive pulmonary disease or heart failure are more likely to experience PPC. The majority of patients undergoing vascular surgery belong in these categories and are at higher risk of developing PPC. Moreover, the surgical site is one of the most important risk factors associated with PPC, and aortic surgery carries the highest risk. The aim of this systematic review was to obtain an additional understanding of the real incidence of PPC after open abdominal aortic surgery and the impact of PPC on survival.

DESIGN

Systematic review and meta-analysis.

SETTING

Hospitals PARTICIPANTS: Patients who underwent open abdominal aortic surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A literature search was performed on BioMedCentral, PubMed, Embase, and the Cochrane Register of clinical trials. All prospective or retrospective studies reporting data on PPC after open abdominal aortic surgery were included. Co-primary endpoints were the PPC rate and the correlation between PPC and perioperative mortality. The secondary endpoint was the difference in the PPC rate and mortality between elective and urgent surgery. Data on 269,637 patients from 213 studies were analyzed. The overall median incidence of PPC was 10.3% (interquartile range 5.55%-19.1%). Pneumonia, respiratory insufficiency, prolonged mechanical ventilation, need for unplanned mechanical ventilation, atelectasis, acute respiratory distress syndrome, pulmonary edema, and pleural effusions were the most common PPC reported in the literature. Occurrence of PPC was associated with postoperative mortality (r = 0.65, p<0.01) and was significantly higher in urgent procedures (p<0.001).

CONCLUSIONS

Incidence of PPC after open abdominal aortic surgery is high and is associated with increased postoperative morbidity and mortality.

Postoperative respiratory failure necessitating transfer to the intensive care unit in orthopedic surgery patients: risk factors, costs, and outcomes

Background

Postoperative pulmonary complications in orthopedic surgery patients have been associated with worse clinical outcomes. Identifying patients with respiratory risk factors requiring enhanced monitoring and management modifications is an important part of postoperative care. Patients with unanticipated respiratory decompensation requiring transfer to the intensive care unit (ICU) have not been studied in sufficient detail.

Methods

A retrospective case-control study of elective orthopedic surgery patients (knee, hip, shoulder, or spine, n = 51) who developed unanticipated respiratory failure (RF) necessitating transfer to the ICU over a 3-year period was conducted. Controls (n = 153) were frequency matched to cases by gender, age, and surgical procedure. Patient and perioperative care factors, clinical outcomes, and cost of care were examined.

Results

Transfer to the ICU occurred within 48 h of surgery in 73 % of the cases, 31 % required non-invasive ventilation, and 18 % required mechanical ventilation. Cases had a higher prevalence of chronic obstructive pulmonary disease (COPD), obstructive sleep apnea (OSA), and regular psychotropic medication use than controls. Cases received more intravenous opioids during the first 24 postoperative hours, were hospitalized 4 days longer, had higher in-hospital mortality, and had excess hospitalization costs of US$26,571. COPD, OSA, preoperative psychotropic medications, and anesthesia time were associated with risk of RF in a multivariate analysis.

Conclusions

Unanticipated RF after orthopedic surgery is associated with extended hospitalization, increased mortality, and higher cost of care. Hospital protocols that include risk factor assessment, enhanced monitoring, and a cautious approach to opioid use in high-risk patients may reduce the frequency of this complication.

Development and validation of a score to predict postoperative respiratory failure in a multicentre European cohort: A prospective, observational study

BACKGROUND

Postoperative respiratory failure (PRF) is the most frequent respiratory complication following surgery.

OBJECTIVE

The objective of this study was to build a clinically useful predictive model for the development of PRF.

DESIGN

A prospective observational study of a multicentre cohort.

SETTING

Sixty-three hospitals across Europe.

PATIENTS

Patients undergoing any surgical procedure under general or regional anaesthesia during 7-day recruitment periods.

MAIN OUTCOME MEASURES

Development of PRF within 5 days of surgery. PRF was defined by a partial pressure of oxygen in arterial blood (PaO2) less than 8 kPa or new onset oxyhaemoglobin saturation measured by pulse oximetry (SpO2) less than 90% whilst breathing room air that required conventional oxygen therapy, noninvasive or invasive mechanical ventilation.

RESULTS

PRF developed in 224 patients (4.2% of the 5384 patients studied). In-hospital mortality [95% confidence interval (95% CI)] was higher in patients who developed PRF [10.3% (6.3 to 14.3) vs. 0.4% (0.2 to 0.6)]. Regression modelling identified a predictive PRF score that includes seven independent risk factors: low preoperative SpO2; at least one preoperative respiratory symptom; preoperative chronic liver disease; history of congestive heart failure; open intrathoracic or upper abdominal surgery; surgical procedure lasting at least 2 h; and emergency surgery. The area under the receiver operating characteristic curve (c-statistic) was 0.82 (95% CI 0.79 to 0.85) and the Hosmer-Lemeshow goodness-of-fit statistic was 7.08 (P = 0.253).

CONCLUSION

A risk score based on seven objective, easily assessed factors was able to predict which patients would develop PRF. The score could potentially facilitate preoperative risk assessment and management and provide a basis for testing interventions to improve outcomes.The study was registered at ClinicalTrials.gov (identifier NCT01346709).

Risk Factors for Postoperative Pulmonary Complications after Abdominal Surgery

BACKGROUND

Incidence of postoperative pulmonary complications (PPC) in patients undergoing non-cardiothoracic surgery remains high and the occurrence of these complications has enormous implications for the patient and the health care system.

AIM

The aim of the study was to identify risk factors for PPC in patients undergoing abdominal surgical procedures.

MATERIALS AND METHODS

A prospective cohort study in abdominal surgical patients, admitted to the emergency and surgical ward of the UHC of Tirana, Albania, was conducted during the period: March 2014-March 2015. We collected data on the occurrence of a symptomatic and clinically significant PPC using clinical, laboratory, and radiology data. We evaluated the relations between PPCs and various pre-operative or intra-operative factors to identify risk factors.

RESULTS

A total of 450 postoperative patients admitted to the surgical emergency and surgical ward were studied. The mean age were 59.85 ±13.64 years with 59.3% being male. Incidence of PPC was 27.3% (123 patients) and hospital length of stay was 4.93 ± 4.65 days. Length of stay was substantially prolonged for those patients who developed PPC (7.48 ± 2.89 days versus 3.97± 4.83 days, p < 0.0001. PPC were identified as risk factors for mortality, OR: 21.84; 95% CI: 11.66-40.89; P < 0.0001. The multivariate regression analysis identified as being independently associated with an increased risk of PPC: age ≥ 65 years (OR 11.41; 95% CI: 4.84-26.91, p < 0.0001), duration of operation ≥ 2.5 hours (OR 8.38; 95% CI: 1.52-46.03, p = 0.01, history of previous pulmonary diseases (OR 11.12; 95% CI: 3.28-37.65, P = 0.0001) and ASA > 2 (OR 6.37; 95% CI: 1.54-26.36, P = 0.01).

CONCLUSION

We must do some efforts in reducing postoperative pulmonary complications, firstly to identify which patients are at increased risk, and then following more closely high-risk patients because those patients are most likely to benefit.

Data, Big Data, and Metadata in Anesthesiology

The last decade has seen an explosion in the growth of digital data. Since 2005, the total amount of digital data created or replicated on all platforms and devices has been doubling every 2 years, from an estimated 132 exabytes (132 billion gigabytes) in 2005 to 4.4 zettabytes (4.4 trillion gigabytes) in 2013, and a projected 44 zettabytes (44 trillion gigabytes) in 2020. This growth has been driven in large part by the rise of social media along with more powerful and connected mobile devices, with an estimated 75% of information in the digital universe generated by individuals rather than entities. Transactions and communications including payments, instant messages, Web searches, social media updates, and online posts are all becoming part of a vast pool of data that live "in the cloud" on clusters of servers located in remote data centers. The amount of accumulating data has become so large that it has given rise to the term Big Data. In many ways, Big Data is just a buzzword, a phrase that is often misunderstood and misused to describe any sort of data, no matter the size or complexity. However, there is truth to the assertion that some data sets truly require new management and analysis techniques.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Postoperative Noninvasive Ventilation Following Cardiothoracic Surgery

Postoperative pulmonary complications following cardiac and thoracic surgery are common and associated with significant morbidity and mortality. Noninvasive ventilation has emerged as a successful and well-validated strategy to treat various acute medical conditions. More recently, noninvasive ventilation has been studied in selective surgical patient populations with the goal of preventing postoperative complications and treating acute respiratory failure. In this clinical review, we will briefly examine the incidence of pulmonary complications following cardiothoracic surgery and the physiology and mechanics of acute respiratory failure and noninvasive ventilation. We then present a systematic review of the indications, patient selection, and current literature investigating the specific use of noninvasive ventilation in this population.

Intraoperative protective mechanical ventilation for prevention of postoperative pulmonary complications: a comprehensive review of the role of tidal volume, positive end-expiratory pressure, and lung recruitment maneuvers

Postoperative pulmonary complications are associated with increased morbidity, length of hospital stay, and mortality after major surgery. Intraoperative lung-protective mechanical ventilation has the potential to reduce the incidence of postoperative pulmonary complications. This review discusses the relevant literature on definition and methods to predict the occurrence of postoperative pulmonary complication, the pathophysiology of ventilator-induced lung injury with emphasis on the noninjured lung, and protective ventilation strategies, including the respective roles of tidal volumes, positive end-expiratory pressure, and recruitment maneuvers. The authors propose an algorithm for protective intraoperative mechanical ventilation based on evidence from recent randomized controlled trials.

Incidence and risk factors of postoperative pulmonary complications in noncardiac Chinese patients: a multicenter observational study in university hospitals

Purpose. To assess the incidence of postoperative pulmonary complications (PPCs) in Chinese inpatients, and to develop a brief predictive risk index. Methods. Between August 6, 2012, and August 12, 2012, patients undergoing noncardiac operations in four university hospitals were enrolled. The cohort was divided into two subsamples, cohort 1 to develop a predictive risk index of PPCs and cohort 2 to validate it. Results. 1673 patients were enrolled. PPCs were recorded for 163 patients (9.7%), of whom the hospital length of stay (LOS) was longer (P < 0.001). The mortality was 1.84% in patients with PPCs and 0.07% in those without. Logistic Regression modeling in cohort 1 identified nine independent risk factors, including smoking, respiratory infection in the last month, preoperative antibiotic use, preoperative saturation of peripheral oxygen, surgery site, blood lost, postoperative blood glucose, albumin, and ventilation. The model was validated within cohort 2 with an area under the receiver operating characteristic curve of 0.90 (95% CI 0.86 to 0.94). Conclusions. PPCs are common in noncardiac surgical patients and are associated with prolonged LOS in China. The current study developed a risk index, which can be used to assess individual risk of PPCs and guide individualized perioperative respiratory care.

Predicting postoperative pulmonary complications: implications for outcomes and costs

PURPOSE OF REVIEW

This review of progress toward reliable prediction of postoperative pulmonary complications (PPCs) discusses risk assessment against the background of patient management strategies, clinical outcomes, and cost of healthcare.

RECENT FINDINGS

Among the variety of conditions grouped as PPCs are pneumonia, aspiration pneumonitis, respiratory failure, reintubation within 48 h, weaning failure, pleural effusion, atelectasis, bronchospasm, and pneumothorax. PPC incidence rates range from 2 to 40% depending on context. These events increase mortality, postoperative length of stay, ICU admissions, hospital readmissions, and costs. PPC-associated mortality varies, but can reach as high as 48% in some contexts. ICU admission rates are between 9.5 and 91% higher in patients with PPCs. The mean increase in PPC-related postoperative length of stay is approximately 8 days. The cost of surgery can be two-fold to 12-fold higher when PPCs develop. Strategies proposed to reduce the impact of modifiable risk factors include alcohol and smoking abstinence before surgery, shortening the duration of surgery, and physiotherapy and incentive spirometry techniques; however, little scientific evidence supports them at this time.

SUMMARY

PPCs are associated with a higher incidence of life-threatening events and higher costs. Reliable PPC risk-stratification tools are essential for guiding clinical decision-making in the perioperative period. The care team can act on modifiable factors and optimize vigilance over nonmodifiable ones. It would be useful to focus resources on determining whether low-cost preemptive interventions improve outcomes satisfactorily or new strategies need to be developed.

Postoperative respiratory failure: pathogenesis, prediction, and prevention

PURPOSE OF REVIEW

This review discusses our present understanding of postoperative respiratory failure (PRF) pathogenesis, risk factors, and perioperative-risk reduction strategies.

RECENT FINDINGS

PRF, the most frequent postoperative pulmonary complication, is defined by impaired blood gas exchange appearing after surgery. PRF leads to longer hospital stays and higher mortality. The time frame for recognizing when respiratory failure is related to the surgical-anesthetic insult remains imprecise, however, and researchers have used different clinical events instead of blood gas measures to define the outcome. Still, studies in specific surgical populations or large patient samples have identified a range of predictors of PRF risk: type of surgery and comorbidity, mechanical ventilation, and multiple hits to the lung have been found to be relevant in most of these studies. Recently, risk-scoring systems for PRF have been developed and are being applied in new controlled trials of PRF-risk reduction measures. Current evidence favors carefully managing intraoperative ventilator use and fluids, reducing surgical aggression, and preventing wound infection and pain.

SUMMARY

PRF is a life-threatening event that is challenging for the surgical team. Risk prediction scales based on large population studies are being developed and validated. We need high-quality trials of preventive measures, particularly those related to ventilator use in both high risk and general populations.

Brazilian recommendations of mechanical ventilation 2013. Part 2

Perspectives on invasive and noninvasive ventilatory support for critically ill patients are evolving, as much evidence indicates that ventilation may have positive effects on patient survival and the quality of the care provided in intensive care units in Brazil. For those reasons, the Brazilian Association of Intensive Care Medicine (Associação de Medicina Intensiva Brasileira - AMIB) and the Brazilian Thoracic Society (Sociedade Brasileira de Pneumologia e Tisiologia - SBPT), represented by the Mechanical Ventilation Committee and the Commission of Intensive Therapy, respectively, decided to review the literature and draft recommendations for mechanical ventilation with the goal of creating a document for bedside guidance as to the best practices on mechanical ventilation available to their members. The document was based on the available evidence regarding 29 subtopics selected as the most relevant for the subject of interest. The project was developed in several stages, during which the selected topics were distributed among experts recommended by both societies with recent publications on the subject of interest and/or significant teaching and research activity in the field of mechanical ventilation in Brazil. The experts were divided into pairs that were charged with performing a thorough review of the international literature on each topic. All the experts met at the Forum on Mechanical Ventilation, which was held at the headquarters of AMIB in São Paulo on August 3 and 4, 2013, to collaboratively draft the final text corresponding to each sub-topic, which was presented to, appraised, discussed and approved in a plenary session that included all 58 participants and aimed to create the final document.

Prospective External Validation of a Predictive Score for Postoperative Pulmonary Complications

Background:

No externally validated risk score for postoperative pulmonary complications (PPCs) is currently available. The authors tested the generalizability of the Assess Respiratory Risk in Surgical Patients in Catalonia risk score for PPCs in a large European cohort (Prospective Evaluation of a RIsk Score for postoperative pulmonary COmPlications in Europe).

Methods:

Sixty-three centers recruited 5,859 surgical patients receiving general, neuraxial, or plexus block anesthesia. The Assess Respiratory Risk in Surgical Patients in Catalonia factors (age, preoperative arterial oxygen saturation in air, acute respiratory infection during the previous month, preoperative anemia, upper abdominal or intrathoracic surgery, surgical duration, and emergency surgery) were recorded, along with PPC occurrence (respiratory infection or failure, bronchospasm, atelectasis, pleural effusion, pneumothorax, or aspiration pneumonitis). Discrimination, calibration, and diagnostic accuracy measures of the Assess Respiratory Risk in Surgical Patients in Catalonia score’s performance were calculated for the Prospective Evaluation of a RIsk Score for postoperative pulmonary COmPlications in Europe cohort and three subsamples: Spain, Western Europe, and Eastern Europe.

Results:

The full Prospective Evaluation of a RIsk Score for postoperative pulmonary COmPlications in Europe data set included 5,099 patients; 725 PPCs were recorded for 404 patients (7.9%). The score’s discrimination was good: c-statistic (95% CI), 0.80 (0.78 to 0.82). Predicted versus observed PPC rates for low, intermediate, and high risk were 0.87 and 3.39% (score &lt;26), 7.82 and 12.98% (≥26 and &lt;45), and 38.13 and 38.01% (≥45), respectively; the positive likelihood ratio for a score of 45 or greater was 7.12 (5.93 to 8.56). The score performed best in the Western Europe subsample—c-statistic, 0.87 (0.83 to 0.90) and positive likelihood ratio, 11.56 (8.63 to 15.47)—and worst in the Eastern Europe subsample. The predicted (5.5%) and observed (5.7%) PPC rates were most similar in the Spain subsample.

Conclusions:

The Assess Respiratory Risk in Surgical Patients in Catalonia score predicts three levels of PPC risk in hospitals outside the development setting. Performance differs between geographic areas.

Anaesthetic perioperative management of patients with pancreatic cancer

Pancreatic cancer remains a significant and unresolved therapeutic challenge. Currently, the only curative treatment for pancreatic cancer is surgical resection. Pancreatic surgery represents a technically demanding major abdominal procedure that can occasionally lead to a number of pathophysiological alterations resulting in increased morbidity and mortality. Systemic, rather than surgical complications, cause the majority of deaths. Because patients are increasingly referred to surgery with at advanced ages and because pancreatic surgery is extremely complex, anaesthesiologists and surgeons play a crucial role in preoperative evaluations and diagnoses for surgical intervention. The anaesthetist plays a key role in perioperative management and can significantly influence patient outcome. To optimise overall care, patients should be appropriately referred to tertiary centres, where multidisciplinary teams (surgical, medical, radiation oncologists, gastroenterologists, interventional radiologists and anaesthetists) work together and where close cooperation between surgeons and anaesthesiologists promotes the safe performance of major gastrointestinal surgeries with acceptable morbidity and mortality rates. In this review, we sought to provide simple daily recommendations to the clinicians who manage pancreatic surgery patients to make their work easier and suggest a joint approach between surgeons and anaesthesiologists in daily decision making.

Pulmonary Complications following Percutaneous Nephrolithotomy: A Prospective Study

INTRODUCTION

Pulmonary complications may occur in the post-operative period and are a significant cause of morbidity and mortality in patients undergoing anesthesia and surgery. Complication rates vary according to different procedures and different types of anesthesia and may be affected by the patient condition. The purpose of this study was to examine pulmonary complications following percutaneous nephrolithotomy (PCNL) and to search for associations between the pre- and intra-operative factors and the risk of post-operative pulmonary complications (PPC).

PATIENTS AND METHODS

This was a prospective observational study of 100 consecutive adult patients who underwent PCNL surgery. We collected data of the patient, surgery and anesthesia and analyzed it to find correlations with PPC.

RESULTS

Eight (8%) patients had PPC following PCNL, 7 patients had pneumothorax and 1 had atelectasis and pleural effusion. The latter patient died at post-operative day 24 due to respiratory failure. It was found that patients who had PCNL on the right kidney were at lower risk for PPC. In addition it was found that younger patients had a higher incidence of PPC.

CONCLUSIONS

Based on this study the most common type of post-operative complication following PCNL is pulmonary, with pneumothorax being the main complication. PPC may result in patient mortality. The side of the operation and the patient's age might affect the risk of PPC.