Intraoperative ventilator settings and their association with postoperative pulmonary complications in neurosurgical patients: post-hoc analysis of LAS VEGAS study.

BACKGROUND: Limited information is available regarding intraoperative ventilator settings and the incidence of postoperative pulmonary complications (PPCs) in patients undergoing neurosurgical procedures. The aim of this post-hoc analysis of the 'Multicentre Local ASsessment of VEntilatory management during General Anaesthesia for Surgery' (LAS VEGAS) study was to examine the ventilator settings of patients undergoing neurosurgical procedures, and to explore the association between perioperative variables and the development of PPCs in neurosurgical patients. METHODS: Post-hoc analysis of LAS VEGAS study, restricted to patients undergoing neurosurgery. Patients were stratified into groups based on the type of surgery (brain and spine), the occurrence of PPCs and the assess respiratory risk in surgical patients in Catalonia (ARISCAT) score risk for PPCs. RESULTS: Seven hundred eighty-four patients were included in the analysis; 408 patients (52%) underwent spine surgery and 376 patients (48%) brain surgery. Median tidal volume (VT) was 8 ml [Interquartile Range, IQR = 7.3-9] per predicted body weight; median positive end-expiratory pressure (PEEP) was 5 [3 to 5] cmH20. Planned recruitment manoeuvres were used in the 6.9% of patients. No differences in ventilator settings were found among the sub-groups. PPCs occurred in 81 patients (10.3%). Duration of anaesthesia (odds ratio, 1.295 [95% confidence interval 1.067 to 1.572]; p = 0.009) and higher age for the brain group (odds ratio, 0.000 [0.000 to 0.189]; p = 0.031), but not intraoperative ventilator settings were independently associated with development of PPCs. CONCLUSIONS: Neurosurgical patients are ventilated with low VT and low PEEP, while recruitment manoeuvres are seldom applied. Intraoperative ventilator settings are not associated with PPCs.

Development of a prediction model for postoperative pneumonia: A multicentre prospective observational study.

BACKGROUND: Postoperative pneumonia is associated with increased morbidity, mortality and costs. Prediction models of pneumonia that are currently available are based on retrospectively collected data and administrative coding systems. OBJECTIVE: To identify independent variables associated with the occurrence of postoperative pneumonia. DESIGN: A prospective observational study of a multicentre cohort (Prospective Evaluation of a RIsk Score for postoperative pulmonary COmPlications in Europe database). SETTING: Sixty-three hospitals in Europe. PATIENTS: Patients undergoing surgery under general and/or regional anaesthesia during a 7-day recruitment period. MAIN OUTCOME MEASURE: The primary outcome was postoperative pneumonia. DEFINITION: the need for treatment with antibiotics for a respiratory infection and at least one of the following criteria: new or changed sputum; new or changed lung opacities on a clinically indicated chest radiograph; temperature more than 38.3 °C; leucocyte count more than 12 000 µl. RESULTS: Postoperative pneumonia occurred in 120 out of 5094 patients (2.4%). Eighty-two of the 120 (68.3%) patients with pneumonia required ICU admission, compared with 399 of the 4974 (8.0%) without pneumonia (P < 0.001). We identified five variables independently associated with postoperative pneumonia: functional status [odds ratio (OR) 2.28, 95% confidence interval (CI) 1.58 to 3.12], pre-operative SpO2 values while breathing room air (OR 0.83, 95% CI 0.78 to 0.84), intra-operative colloid administration (OR 2.97, 95% CI 1.94 to 3.99), intra-operative blood transfusion (OR 2.19, 95% CI 1.41 to 4.71) and surgical site (open upper abdominal surgery OR 3.98, 95% CI 2.19 to 7.59). The model had good discrimination (c-statistic 0.89) and calibration (Hosmer-Lemeshow P = 0.572). CONCLUSION: We identified five variables independently associated with postoperative pneumonia. The model performed well and after external validation may be used for risk stratification and management of patients at risk of postoperative pneumonia. TRIAL REGISTRATION: NCT 01346709 (ClinicalTrials.gov).

Survival and quality of life after surgery for colorectal cancer in the elderly: a comparative study.

BACKGROUND: the aim of this study was to analyze the clinical results of the multidisciplinary management of elderly patients with colorectal cancer in a single center and to describe postoperative quality of life. METHODS: a comparative study was designed to compare the results and quality of life of patients treated in our center for colon cancer, aged from 80 to 84 years (study group) compared to a control group (aged form 75 to 79 years of age). Morbidity, mortality, oncological results and quality of life were analyzed. RESULTS: eighty-seven patients aged between 80 and 84 years of age (study group) were compared to a control group, which was formed by 91 patients aged from 75 to 79 years of age. There were no significant differences in technique and morbidity. Survival at 30 days, 90 days and at the end of follow-up (median 48 months) were similar in both groups. There were no differences in quality of life except for one item with regard to physical function (p = 0.0138). CONCLUSION: similar clinical results and quality of life were achieved after treating elderly patients with colon cancer with a multidisciplinary management approach.

The LAS VEGAS risk score for prediction of postoperative pulmonary complications: An observational study.

BACKGROUND: Currently used pre-operative prediction scores for postoperative pulmonary complications (PPCs) use patient data and expected surgery characteristics exclusively. However, intra-operative events are also associated with the development of PPCs. OBJECTIVE: We aimed to develop a new prediction score for PPCs that uses both pre-operative and intra-operative data. DESIGN: This is a secondary analysis of the LAS VEGAS study, a large international, multicentre, prospective study. SETTINGS: A total of 146 hospitals across 29 countries. PATIENTS: Adult patients requiring intra-operative ventilation during general anaesthesia for surgery. INTERVENTIONS: The cohort was randomly divided into a development subsample to construct a predictive model, and a subsample for validation. MAIN OUTCOME MEASURES: Prediction performance of developed models for PPCs. RESULTS: Of the 6063 patients analysed, 10.9% developed at least one PPC. Regression modelling identified 13 independent risk factors for PPCs: six patient characteristics [higher age, higher American Society of Anesthesiology (ASA) physical score, pre-operative anaemia, pre-operative lower SpO2 and a history of active cancer or obstructive sleep apnoea], two procedure-related features (urgent or emergency surgery and surgery lasting ≥ 1 h), and five intra-operative events [use of an airway other than a supraglottic device, the use of intravenous anaesthetic agents along with volatile agents (balanced anaesthesia), intra-operative desaturation, higher levels of positive end-expiratory pressures > 3 cmH2O and use of vasopressors]. The area under the receiver operating characteristic curve of the LAS VEGAS risk score for prediction of PPCs was 0.78 [95% confidence interval (95% CI), 0.76 to 0.80] for the development subsample and 0.72 (95% CI, 0.69 to 0.76) for the validation subsample. CONCLUSION: The LAS VEGAS risk score including 13 peri-operative characteristics has a moderate discriminative ability for prediction of PPCs. External validation is needed before use in clinical practice. TRIAL REGISTRATION: The study was registered at Clinicaltrials.gov, number NCT01601223.

Genetic and Clinical Factors Associated with Chronic Postsurgical Pain after Hernia Repair, Hysterectomy, and Thoracotomy: A Two-year Multicenter Cohort Study.

BACKGROUND: Chronic postsurgical pain (CPSP) has been linked to many surgical settings. The authors aimed to analyze functional genetic polymorphisms and clinical factors that might identify CPSP risk after inguinal hernia repair, hysterectomy, and thoracotomy. METHODS: This prospective multicenter cohort study enrolled 2,929 patients scheduled for inguinal hernia repair, hysterectomy (vaginal or abdominal), or thoracotomy. The main outcome was the incidence of CPSP confirmed by physical examination 4 months after surgery. The secondary outcome was CPSP incidences at 12 and 24 months. The authors also tested the associations between CPSP and 90 genetic markers plus a series of clinical factors and built a CPSP risk model. RESULTS: Within a median of 4.4 months, CPSP had developed in 527 patients (18.0%), in 13.6% after hernia repair, 11.8% after vaginal hysterectomy, 25.1% after abdominal hysterectomy, and 37.6% after thoracotomy. CPSP persisted after a median of 14.6 months and 26.3 months in 6.2% and 4.1%, respectively, after hernia repair, 4.1% and 2.2% after vaginal hysterectomy, 9.9% and 6.7% after abdominal hysterectomy, and 19.1% and 13.2% after thoracotomy. No significant genetic differences between cases and controls were identified. The risk model included six clinical predictors: (1) surgical procedure, (2) age, (3) physical health (Short Form Health Survey-12), (4) mental health (Short Form Health Survey-12), (5) preoperative pain in the surgical field, and (6) preoperative pain in another area. Discrimination was moderate (c-statistic, 0.731; 95% CI, 0.705 to 0.755). CONCLUSIONS: Until unequivocal genetic predictors of CPSP are understood, the authors encourage systematic use of clinical factors for predicting and managing CPSP risk.

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.

Protective versus Conventional Ventilation for Surgery: A Systematic Review and Individual Patient Data Meta-analysis.

BACKGROUND: Recent studies show that intraoperative mechanical ventilation using low tidal volumes (VT) can prevent postoperative pulmonary complications (PPCs). The aim of this individual patient data meta-analysis is to evaluate the individual associations between VT size and positive end-expiratory pressure (PEEP) level and occurrence of PPC. METHODS: Randomized controlled trials comparing protective ventilation (low VT with or without high levels of PEEP) and conventional ventilation (high VT with low PEEP) in patients undergoing general surgery. The primary outcome was development of PPC. Predefined prognostic factors were tested using multivariate logistic regression. RESULTS: Fifteen randomized controlled trials were included (2,127 patients). There were 97 cases of PPC in 1,118 patients (8.7%) assigned to protective ventilation and 148 cases in 1,009 patients (14.7%) assigned to conventional ventilation (adjusted relative risk, 0.64; 95% CI, 0.46 to 0.88; P < 0.01). There were 85 cases of PPC in 957 patients (8.9%) assigned to ventilation with low VT and high PEEP levels and 63 cases in 525 patients (12%) assigned to ventilation with low VT and low PEEP levels (adjusted relative risk, 0.93; 95% CI, 0.64 to 1.37; P = 0.72). A dose-response relationship was found between the appearance of PPC and VT size (R2 = 0.39) but not between the appearance of PPC and PEEP level (R2 = 0.08). CONCLUSIONS: These data support the beneficial effects of ventilation with use of low VT in patients undergoing surgery. Further trials are necessary to define the role of intraoperative higher PEEP to prevent PPC during nonopen abdominal surgery.

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).

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 <26), 7.82 and 12.98% (≥ 26 and <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.

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.

Collaborative intervention to improve airway assessment and safety in management for anaesthesia: the Qualitat & Via Aèria (QUAVA) study.

BACKGROUND: Airway assessment and management are cornerstones of anaesthesia, yet airway complications remain an important source of morbidity. OBJECTIVE: We performed a before-and-after evaluation of a collaborative intervention to improve adherence to airway assessment and management guidelines in patients scheduled for surgery under general anaesthesia. DESIGN: A prospective, multicentre before-and-after evaluation of a collaborative intervention. SETTING: Collaborative intervention to improve adherence to airway assessment and management guidelines in patients scheduled for surgery under general anaesthesia. Data were collected on 21 consecutive days before and after the intervention. PARTICIPANTS: Anaesthetists with staff or residency positions at 22 hospitals. Patients aged 18 years or older undergoing nonemergency surgery were recruited. INTERVENTION: Establishing a learning network that included local leaders, meetings to share experiences and knowledge, interactive sessions and provision of printed materials on airway assessment and management. Clinical airway management for general anaesthesia was provided by the anaesthetists participating in the study. MAIN OUTCOME MEASURES: Outcomes were the completion of airway assessment at the preanaesthetic visit, rates of unanticipated difficult airway, algorithm adherence and related airway complications. RESULTS: The study included 3753 patients (1947 preintervention and 1806 postintervention). The percentage of patients with a complete airway assessment increased from 25.1% preintervention to 48.4% postintervention (P <0.001). The incidences of unanticipated difficult airway were 4.1% before the intervention and 3% after it (P = 0.433). Rates of adherence to the algorithms for anticipated and unanticipated difficult airway management were similar in the two periods. The incidences of related adverse events were also similar. CONCLUSION: The collaborative intervention was effective in improving airway assessment but not in changing difficult airway management practices.

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.

Predicting postoperative pulmonary complications in the general population.

PURPOSE OF REVIEW: Postoperative pulmonary complications (PPCs) are common and lead to longer hospital stays and higher mortality. A wide range of patient, anaesthetic and surgical factors have been associated with risk for PPCs. This review discusses our present understanding of PPC risk factors that can be used to plan preoperative risk reduction strategies. The methodological and statistical basis for building risk scores is also described. RECENT FINDINGS: Studies in specific surgical populations or large patient samples have identified a range of predictors of PPC risk. Factors such as age, types of comorbidity and surgical characteristics have been found to be relevant in most of these studies. Recently, researchers have begun to develop risk scoring systems for a PPC composite outcome or for specific PPCs, especially pneumonia and respiratory failure. Preoperative arterial oxyhaemoglobin saturation is an objective measure that is easy to record and discriminates level of risk for impaired cardiorespiratory function. Preoperative anaemia and recent respiratory infection are factors that have lately been found to confer risk for PPCs. SUMMARY: PPC risk prediction scales based on large population studies are being developed. New studies to confirm the validity of these scales in different geographic areas will be needed before we can be sure of their generalizability.

Validity of the Spanish 8-item short-form generic health-related quality-of-life questionnaire in surgical patients: a population-based study.

BACKGROUND: Health-related quality of life is usually reported for specific rather than heterogeneous populations such as those treated in routine anesthesia practice. The 8-item short-form generic health-related quality-of-life questionnaire (SF-8) is a candidate instrument for this setting. The authors evaluated the feasibility, reliability, validity, and responsiveness to change of the Spanish version of SF-8 in a population-based surgical cohort. METHODS: Recruiting patients from a large population-based study of risk factors for pulmonary complications, before surgery, the authors administered the 1-week recall SF-8 to 2,991 patients undergoing nonobstetric elective or emergency surgery in 59 hospitals, each of which collected data on seven randomly assigned days in 2006. The SF-8 was administered again 3 months later. Reliability was evaluated using the Cronbach alpha coefficient and validity by comparing physical and mental component summary SF-8 scores with clinical variables. Responsiveness after surgery was evaluated using the standardized response mean. RESULTS: Cronbach alpha for the overall test was 0.92. Physical and mental component summary scores and all individual scores were lower (worse quality of life) in women (P < 0. 01) and decreased with age (P < 0.01). Preoperative scores were lower for those in worse clinical condition (higher body mass index, American Society of Anesthesiologists physical status class, or surgical risk scores), with preoperative respiratory symptoms, and in emergency situations (P < 0.01). The standardized response mean ranged from 0.1 to 0.5. CONCLUSIONS: The SF-8 is a feasible, reliable, valid, and responsive instrument for assessing health-related quality of life in a broad-spectrum surgical population.

Prediction of postoperative pulmonary complications in a population-based surgical cohort.

BACKGROUND: Current knowledge of the risk for postoperative pulmonary complications (PPCs) rests on studies that narrowly selected patients and procedures. Hypothesizing that PPC occurrence could be predicted from a reduced set of perioperative variables, we aimed to develop a predictive index for a broad surgical population. METHODS: Patients undergoing surgical procedures given general, neuraxial, or regional anesthesia in 59 hospitals were randomly selected for this prospective, multicenter study. The main outcome was the development of at least one of the following: respiratory infection, respiratory failure, bronchospasm, atelectasis, pleural effusion, pneumothorax, or aspiration pneumonitis. The cohort was randomly divided into a development subsample to construct a logistic regression model and a validation subsample. A PPC predictive index was constructed. RESULTS: Of 2,464 patients studied, 252 events were observed in 123 (5%). Thirty-day mortality was higher in patients with a PPC (19.5%; 95% [CI], 12.5-26.5%) than in those without a PPC (0.5%; 95% CI, 0.2-0.8%). Regression modeling identified seven independent risk factors: low preoperative arterial oxygen saturation, acute respiratory infection during the previous month, age, preoperative anemia, upper abdominal or intrathoracic surgery, surgical duration of at least 2 h, and emergency surgery. The area under the receiver operating characteristic curve was 90% (95% CI, 85-94%) for the development subsample and 88% (95% CI, 84-93%) for the validation subsample. CONCLUSION: The risk index based on seven objective, easily assessed factors has excellent discriminative ability. The index can be used to assess individual risk of PPC and focus further research on measures to improve patient care.