[Postoperative lung complications and mortality in patients with mild-to-moderate COPD undergoing elective general surgery]

Preoperative Spirometry in Patients With Known or Suspected Chronic Obstructive Pulmonary Disease Undergoing Major Surgery: The Prospective Observational PREDICT Study

BACKGROUND

Pulmonary function tests (PFTs) such as spirometry and blood gas analysis have been claimed to improve preoperative pulmonary risk assessment, but the scientific literature is conflicting. The Preoperative Diagnostic Tests for Pulmonary Risk Assessment in Chronic Obstructive Pulmonary Disease (PREDICT) study aimed to determine whether preoperative PFTs improve the prediction of postoperative pulmonary complications (PPCs) in patients with known or suspected chronic obstructive pulmonary disease (COPD) undergoing major surgery. A secondary aim was to determine whether the Global Initiative for Chronic Obstructive Lung Diseases (GOLD) classification of airflow limitation severity (grades I-IV) is associated with PPC.

METHODS

In this prospective, single-center study, patients with GOLD key indicators for COPD scheduled for major surgery received PFTs. Patients with confirmed COPD (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] ≤0.7) were included in the COPD cohort and compared with a reference cohort without COPD. We developed 3 multivariable risk prediction models and compared their ability to predict PPC: the "standard model" (medical preconditions, and sociodemographic and surgical data), the "COPD assessment model" (additional GOLD key indicators, pack-years, and poor exercise capacity), and the "PFT model" (additional PFT parameters selected by adaptive least absolute shrinkage and selection operator [LASSO] regression). Multiple LASSO regressions were used for cross-validation.

RESULTS

A total of 31,714 patients were assessed for eligibility; 1271 individuals received PFTs. Three hundred twenty patients (240 with confirmed COPD: 78 GOLD I, 125 GOLD II, 28 GOLD III, 9 GOLD IV, and 80 without COPD) completed follow-up. The diagnostic performance was similar among the standard model (cross-validated area under the curve [cvAUC], 0.723; bias-corrected bootstrapped [bc-b] 95% confidence interval [CI], 0.663-0.775), COPD assessment model (cvAUC, 0.724; bc-b 95% CI, 0.662-0.777), and PFT model (cvAUC, 0.729; bc-b 95% CI, 0.668-0.782). Previously known COPD was an independent predictor in the standard and COPD assessment model. %FEV1 PRED was the only PFT parameter selected by LASSO regression and was an independent predictor in the PFT model (adjusted odds ratios [OR], 0.98; 95% CI, 0.967-.0.998; P = .030). The risk for PPC significantly increased with GOLD grades ( P < .001). COPD was newly diagnosed in 53.8% of the patients with confirmed COPD; however, these individuals were not at increased risk for PPC ( P = .338).

CONCLUSIONS

COPD is underdiagnosed in surgical patients. Patients with newly diagnosed COPD commonly presented with low GOLD severity grades and were not at higher risk for PPC. Neither a structured COPD-specific assessment nor preoperative PFTs added incremental diagnostic value to the standard clinical preassessment in patients with known or suspected COPD. Unnecessary postponement of surgery and undue health care costs can be avoided.

Feasibility of Nonintubated Anesthesia for Lumboperitoneal Shunt Implantation

Lumboperitoneal shunt (LPS) implantation is a cerebrospinal fluid diversion therapy for the communicating type of normal-pressure hydrocephalus (NPH); NPH mainly affects older adults. However, endotracheal intubation for mechanical ventilation with muscle relaxant increases perioperative and postoperative risks for this population. Based on knowledge from nonintubated thoracoscopic surgery, which has been widely performed in recent years, we describe a novel application of nonintubated anesthesia for LPS implantation in five patients. Anesthesia without muscle relaxants, with a laryngeal mask in one patient and a high-flow nasal cannula in four patients, was used to maintain spontaneous breathing during the surgery. The mean anesthesia time was 103.8 min, and the mean operative duration was 55.8 min. All patients recovered from anesthesia uneventfully. In our experience, nonintubated LPS surgery appears to be a promising and safe surgical technique for appropriately selected patients with NPH.

Association of preoperative systemic corticosteroid therapy with surgical outcomes in chronic obstructive pulmonary disease patients

BACKGROUND:

Chronic obstructive pulmonary disease (COPD) patients are at an increased risk of postoperative pulmonary complications (PPCs). The purpose of this study is to evaluate the risks and benefits associated with preoperative steroids in COPD patients.

METHODS:

The National Surgical Quality Improved Program database was used to identify 92 COPD patients who underwent surgery at the American University of Beirut Medical Center between 2009 and 2013. COPD was diagnosed based on postbronchodilator forced expiratory volume in 1 s to forced vital capacity ratio <0.7 and a history of smoking. The exposure of interest was preoperative systemic corticosteroid therapy. The primary outcomes were PPCs and wound complications. Cardiac and urinary complications along with unplanned readmission or reoperation and death were also evaluated.

RESULTS:

Overall 42.4% of patients received preoperative systemic corticosteroids. Postoperative wound complications were significantly more frequent in COPD patients who received preoperative systemic corticosteroids compared to patients who did not (10.3% vs. none, respectively, P = 0.03). However, PPCs were not significantly different between patients who received preoperative systemic corticosteroids and patients who did not (17.9% vs. 13.2%, respectively, P = 0.53). There were no significant differences in the secondary outcomes.

CONCLUSIONS:

This study suggests that preoperative administration of systemic corticosteroids in stable COPD patients is associated with an increased risk of postoperative wound complications but may not reduce PPCs.

Respiratory evaluation of the risk for postoperative pulmonary complications in patients who preoperatively consulted pulmonologists: Studying both patients who underwent and who precluded planned surgery

BACKGROUND

Due to advances in medicine, patients with pulmonary diseases have become candidates for surgery under general anesthesia. They often consult pulmonologists to assess their tolerability for surgery. The purpose of this study was to evaluate the significant characteristics responsible for postoperative pulmonary complications (PPCs) and the preclusion of the planned surgery.

METHODS

The clinical data of 462 consecutive patients who consulted at the Department of Respiratory Medicine before surgery under general anesthesia were used in this study. The relationship between the patient׳s characteristics and their outcomes were analyzed. The patients who were scheduled for lung resection were excluded.

RESULTS

Of the 386 patients who underwent planned surgery, 353 had no PPCs (Group A) and 33 developed PPCs (Group B). Planned surgery under general anesthesia was precluded in 31 patients due to respiratory problems (Group C). The significant predictors for PPCs consisted of a higher age, male gender, asthma, gastrointestinal surgery, cardiovascular surgery and a lower percentage of the predicted forced expiratory volume in 1 second (% predicted FEV₁). The significant factors associated with the preclusion of planned surgery included interstitial pneumonia (IP), dermatologic surgery and a lower % predicted FEV₁. The predicted probability of PPCs in Group C was significantly higher than that in Group A and lower than that in Group B (all p-values < 0.05).

CONCLUSION

The common clinical finding for predicting PPCs and encouraging the preclusion of the planned surgery under general anesthesia was a lower % predicted FEV₁.

Development of the Combined Assessment of Risk Encountered in Surgery (CARES) surgical risk calculator for prediction of postsurgical mortality and need for intensive care unit admission risk: a single-center retrospective study

INTRODUCTION

Accurate surgical risk prediction is paramount in clinical shared decision making. Existing risk calculators have limited value in local practice due to lack of validation, complexities and inclusion of non-routine variables.

OBJECTIVE

We aim to develop a simple, locally derived and validated surgical risk calculator predicting 30-day postsurgical mortality and need for intensive care unit (ICU) stay (>24 hours) based on routinely collected preoperative variables. We postulate that accuracy of a clinical history-based scoring tool could be improved by including readily available investigations, such as haemoglobin level and red cell distribution width.

METHODOLOGY

Electronic medical records of 90 785 patients, who underwent non-cardiac and non-neuro surgery between 1 January 2012 and 31 October 2016 in Singapore General Hospital, were retrospectively analysed. Patient demographics, comorbidities, laboratory results, surgical priority and surgical risk were collected. Outcome measures were death within 30 days after surgery and ICU admission. After excluding patients with missing data, the final data set consisted of 79 914 cases, which was divided randomly into derivation (70%) and validation cohort (30%). Multivariable logistic regression analysis was used to construct a single model predicting both outcomes using Odds Ratio (OR) of the risk variables. The ORs were then assigned ranks, which were subsequently used to construct the calculator.

RESULTS

Observed mortality was 0.6%. The Combined Assessment of Risk Encountered in Surgery (CARES) surgical risk calculator, consisting of nine variables, was constructed. The area under the receiver operating curve (AUROC) in the derivation and validation cohorts for mortality were 0.934 (0.917-0.950) and 0.934 (0.912-0.956), respectively, while the AUROC for ICU admission was 0.863 (0.848-0.878) and 0.837 (0.808-0.868), respectively. CARES also performed better than the American Society of Anaesthesiologists-Physical Status classification in terms of AUROC comparison.

CONCLUSION

The development of the CARES surgical risk calculator allows for a simplified yet accurate prediction of both postoperative mortality and need for ICU admission after surgery.

Do preoperative pulmonary function indices predict morbidity after coronary artery bypass surgery?

Context:

The reported prevalence of chronic obstructive pulmonary disease (COPD) varies among different groups of cardiac surgical patients. Moreover, the prognostic value of preoperative COPD in outcome prediction is controversial.

Aims:

The present study assessed the morbidity in the different levels of COPD severity and the role of pulmonary function indices in predicting morbidity in patients undergoing coronary artery bypass graft (CABG).

Settings and Design:

Patients who were candidates for isolated CABG with cardiopulmonary bypass who were recruited for Tehran Heart Center-Coronary Outcome Measurement Study.

Methods:

Based on spirometry findings, diagnosis of COPD was considered based on Global Initiative for Chronic Obstructive Lung Disease category as forced expiratory volume in 1 s [FEV1]/forced vital capacity <0.7 (absolute value, not the percentage of the predicted). Society of Thoracic Surgeons (STS) definition was used for determining COPD severity and the patients were divided into three groups: Control group (FEV1 >75% predicted), mild (FEV1 60–75% predicted), moderate (FEV1 50–59% predicted), severe (FEV1<50% predicted). The preoperative pulmonary function indices were assessed as predictors, and postoperative morbidity was considered the surgical outcome.

Results:

This study included 566 consecutive patients. Patients with and without COPD were similar regarding baseline characteristics and clinical data. Hypertension, recent myocardial infarction, and low ejection fraction were higher in patients with different degrees of COPD than the control group while male gender was more frequent in control patients than the others. Restrictive lung disease and current cigarette smoking did not have any significant impact on postoperative complications. We found a borderline P = 0.057 with respect to respiratory failure among different patients of COPD severity so that 14.1% patients in control group, 23.5% in mild, 23.4% in moderate, and 21.9% in severe COPD categories developed respiratory failure after CABG surgery.

Conclusion:

Among post-CABG complications, patients with different levels of COPD based on STS definition, more frequently developed respiratory failure. This finding may imply the prognostic value of preoperative pulmonary function test for determining COPD severity and postoperative morbidities.

Nonintubated anesthesia in thoracic surgery: general issues

Anesthetic management for awake thoracic surgery (ATS) is more difficult than under general anesthesia (GA), being technically extremely challenging for the anesthesiologist. Therefore, thorough preparation and vigilance are paramount for successful patient management. In this review, important considerations of nonintubated anesthesia for thoracic surgery are discussed in view of careful patient selection, anesthetic preparation, potential perioperative difficulties and the management of its complications.

Non-intubated anesthesia in thoracic surgery-technical issues

Performing awake thoracic surgery (ATS) is technically more challenging than thoracic surgery under general anesthesia (GA), but it can result in a greater benefit for the patient. Local wound infiltration and lidocaine administration in the pleural space can be considered for ATS. More invasive techniques are local wound infiltration with wound catheter insertion, thoracic wall blocks, selective intercostal nerve blockade, thoracic paravertebral blockade and thoracic epidural analgesia, offering the advantage of a catheter placement which can also be continued for postoperative analgesia.

Non-intubated video-assisted thoracic surgery management of secondary spontaneous pneumothorax

Secondary spontaneous pneumothorax (SSP) is serious entity, usually due to underlying disease, mainly chronic obstructive pulmonary disease (COPD). Its morbidity and mortality is high due to the pulmonary compromised status of these patients, and the recurrence rate is almost 50%, increasing mortality with each episode. For persistent or recurrent SSP, surgery under general anesthesia (GA) and mechanical ventilation (MV) with lung isolation is the gold standard, but ventilator-induced damages and dependency, and postoperative pulmonary complications are frequent. In the last two decades, several groups have reported successful results with non-intubated video-assisted thoracic surgery (NI-VATS) with thoracic epidural anesthesia (TEA) and/or local anesthesia under spontaneous breathing. Main benefits reported are operative time, operation room time and hospital stay reduction, and postoperative respiratory complications decrease when comparing to GA, thus encouraging for further research in these moderate to high risk patients many times rejected for the standard regimen. There are also reports of special situations with satisfactory results, as in contralateral pneumonectomy and lung transplantation. The aim of this review is to collect, analyze and discuss all the available evidence, and seek for future lines of investigation.

Postoperative complications after thoracic surgery in the morbidly obese patient

Little has been recently published about specific postoperative complications following thoracic surgery in the morbidly obese patient. Greater numbers of patients who are obese, morbidly obese, or supermorbidly obese are undergoing surgical procedures. Postoperative complications after thoracic surgery in these patients that can lead to increased morbidity and mortality, prolonged hospital stay, and increased cost of care are considered. Complications include difficulties with mask ventilation and securing the airway, obstructive sleep apnea with risk of oversedation, pulmonary complications related to reduced total lung capacity, reduced functional residual capacity, and reduced vital capacity, risks of aspiration pneumonitis and ventilator-associated pneumonia, cardiomyopathies, and atrial fibrillation, inadequate diabetes management, positioning injuries, increased risk of venous thrombosis, and pulmonary embolism. The type of thoracic surgical procedure may also pose other problems to consider during the postoperative period. Obese patients undergoing thoracic surgery pose a challenge to those caring for them. Those working with these patients must understand how to recognize, prevent, and manage these postoperative complications.