Annales Franc¸aises d’Anesthe´sie et de Re´animation 33 (2014) 480–483
Monothematic meeting of Sfar 2014
Postoperative pulmonary complications updating§,§§ Complications pulmonaires postope´ratoires : actualisation O. Langeron *, S. Carreira, F. le Sache´, M. Raux Unite´ de surveillance post-interventionnelle et d’accueil des polytraumatise´s, de´partement d’anesthe´sie re´animation, groupe hospitalier Pitie´-Salpeˆtrie`re, Assistance Publique–Hoˆpitaux de Paris, 47-83, boulevard de l’Hoˆpital, 75651 Paris cedex 13, France
A R T I C L E I N F O
A B S T R A C T
Available online 29 August 2014
Postoperative pulmonary complications (PPCs) are a major contributor to the overall risk of surgery. PPCs affect the length of hospital stay and are associated with a higher in-hospital mortality. PPCs are even the leading cause of death either in cardiothoracic surgery but also in non-cardiothoracic surgery. Thus, reliable PPCs risk stratification tools are the key issue of clinical decision making in the perioperative period. When the risk is clearly identified related to the patient according the ARISCAT score and/or the type of surgery (mainly thoracic and abdominal), low-cost preemptive interventions improve outcomes and new strategies can be developed to prevent this risk. The EuSOS, PERISCOPE and IMPROVE studies demonstrated this care optimization by risk identification first, then risk stratification and new care (multifaceted) strategies implementation allowing a decrease in PPCs mortality by optimizing the clinical path of the patient and the care resources. ß 2014 Socie´te´ franc¸aise d’anesthe´sie et de re´animation (Sfar). Published by Elsevier Masson SAS. All rights reserved.
Keywords: Postoperative mortality Postoperative pulmonary complications Risk factors Risk stratification Outcome assessment Preemptive intervention Health care resources
R E´ S U M E´
Mots cle´s : Mortalite´ postope´ratoire Complications pulmonaires postope´ratoires Facteurs de risque Stratification du risque E´valuation du devenir Intervention pre´ventive Ressources de soin
Les complications pulmonaires postope´ratoires (CPP) contribuent grandement au risque pe´riope´ratoire. Les CPPs entraıˆnent une augmentation de la dure´e de se´jour hospitalier et sont associe´es a` une mortalite´ hospitalie`re plus e´leve´e. Les CPP repre´sentent la principale cause de de´ce`s postope´ratoires aussi bien apre`s une chirurgie non cardiothoracique que cardiothoracique. Ainsi, la mise en place d’outils fiables permettant de stratifier le risque de CPP est fondamentale, comme aide pe´riope´ratoire a` la de´cision clinique. En effet, lorsque le risque est clairement identifie´ par l’interme´diaire du score ARISCAT et/ou le ˆ teuses et type de chirurgie (principalement thoracique et abdominale), des mesures pre´ventives peu cou des nouvelles strate´gies peuvent eˆtre instaure´es pour diminuer ce risque de CPP. Les e´tudes EuSOS, PERISCOPE et IMPROVE ont de´montre´ que l’optimisation du soin avec l’identification et la stratification du risque permettaient la mise en place de nouvelles strate´gies (multidirectionnelles) de soins permettant de diminuer la mortalite´ des CPP en optimisant le chemin clinique du patient et les ressources de soin. ß 2014 Socie´te´ franc¸aise d’anesthe´sie et de re´animation (Sfar). Publie´ par Elsevier Masson SAS. Tous droits re´serve´s.
1. Introduction
§
Article presented at Monothematic meeting of Sfar (Socie´te´ franc¸aise d’anesthe´sie et de re´animation): ‘‘Perioperative ventilation’’, Paris, May 21, 2014. §§ This article is published under the responsibility of the Scientific Committee of the ‘‘Journe´e Monothe´matique 2014 de la Sfar’’. The editorial board of the Annales franc¸aises d’anesthe´sie et de re´animation was not involved in the conception and validation of its content. * Corresponding author. E-mail address: [email protected] (O. Langeron).
Mortality after non-cardiac surgery still remains an important issue in Europe, with an overall mortality rate of 4%, higher than the 2% rate expected [1]. In addition, important variations between countries were observed, highlighting the importance of the clinical path of the patients according to their perioperative risk and their clinical status [1]. Postoperative pulmonary complications (PPCs) are a major contributor to the overall risk of surgery. PPCs affect the length of hospital stay and are associated with a
http://dx.doi.org/10.1016/j.annfar.2014.07.741 0750-7658/ß 2014 Socie´te´ franc¸aise d’anesthe´sie et de re´animation (Sfar). Published by Elsevier Masson SAS. All rights reserved.
O. Langeron et al. / Annales Franc¸aises d’Anesthe´sie et de Re´animation 33 (2014) 480–483
higher in-hospital mortality with an estimate of 4.8 million additional days of hospitalization and 46,200 additional deaths in the United States [2]. Thus, PPCs are the leading cause of death either in cardiothoracic surgery but also in non-cardiothoracic surgery [3]. Moreover, PPCs increase financial outcomes of health care, like in the United States with an annual reported economic burden of several billions (US dollars) [2]. Prediction of the perioperative risk, including PPCs is an important issue to decrease the postoperative morbidity, mortality and the surgical hospitalization cost. Some important recent studies are dedicated to this topic and have been reported in thematic day dedicated to perioperative ventilation organized by the Sfar (Socie´te´ franc¸aise d’anesthe´sie et de re´animation) held in Paris on May 2014 the 21st. In this updating, we will first give actual definitions of PPCs and discuss studies improving our knowledge of PPCs: Mortality after surgery in Europe: a 7-day cohort study published in 2012 in Lancet Journal [1]; prospective external validation of a predictive score for postoperative pulmonary complications (PERISCOPE study) published in 2014 in Anesthesiology [4]; a trial of intraoperative lowtidal volume ventilation in abdominal surgery published in 2013 in the New England Journal of Medecine [5]. 2. Definitions of PPCs There is no standard definition of PPCs. They can be broadly defined as conditions affecting the respiratory tract that can adversely influence the clinical course of a patient after surgery. Consequently, incidence rates could vary dramatically from 2% to 40% [6]. Nevertheless, PPCs definitions usually include respiratory failure, tracheal reintubation within 48 hours, weaning failure, pneumonia, atelectasis, bronchospasm, exacerbation of chronic obstructive pulmonary disease, pneumothorax, pleural effusion, and various forms of upper airway obstruction. PPCs have a multifactorial etiology and a lot of perioperative risk factors [6]. One approach to standardize the PPCs could be a physiopathological definition with postoperative decreased functional residual capacity and total lung capacity that result in ventilation-perfusion mismatch and hypoxemia. In clinical studies, postoperative pulmonary complication is defined as the occurrence of at least one postoperative respiratory event in a composite list of inhospital fatal or non-fatal PPCs (Table 1) [4]. Consequently, incidence of PPCs could vary a lot between surgical procedures. For example, thoracic surgery has much higher PPCs incidence (37.8%) than upper abdominal (12.2%) or peripheral (2.2%) surgery [7]. 3. Studies improving our knowledge of PPCs We will illustrate the impact of PPCs according to 3 studies. The main issue of a better knowledge of PPCs occurrence is the necessity to more precisely assess the respiratory risk in surgical patients and thereafter to decrease PPCs risk with preventing procedures. Mortality after surgery in Europe: a 7-day cohort study, named EuSOS study for European surgical outcome study published in 2012 in Lancet Journal [1] is a major study reminding us that variations in postoperative mortality are related to the clinical path of the patient, i.e. with critical care resources. EuSOS was designed to assess outcomes after surgery in Europe, especially to describe first mortality rates and second patterns of critical care resource use for patients undergoing non-cardiac surgery across 28 European nations. A 7-day cohort study collecting data for consecutive patients in selected centres (498 hospitals) either for scheduled or emergency surgery was performed in April 2011. A multilevel logistic regression model to adjust difference in
481
Table 1 PPC: a composite defined as any one or more of a list of in-hospital fatal or non-fatal postoperative PPCs [4]. Respiratory failure (mild, intermediate, or severe) Mild: PaO2 < 60 mmHg or SpO2 < 90% in room air but responding to supplemental oxygen (excluding hypoventilation) Intermediate: need for non-invasive or invasive mechanical ventilation or a PaO2 < 60 mmHg or SpO2 < 90% Severe (ALI/ARDS): need for invasive mechanical ventilation and PaO2/FiO2 < 300 mmHg regardless the level of PEEP Suspected pulmonary infection, in a patient on antibiotics, meeting at least one of the following criteria New or changed sputum New or changed lung opacities on chest x-ray when clinically indicated Temperature > 38.3 8C White cell count > 12,000/mm3 Pleural effusion Chest X-ray demonstrating blunting of the costophrenic angle, loss of the sharp silhouette of the ipsilateral hemidiaphragm (in upright position), evidence of displacement of adjacent anatomical structures, or (in supine position) a hazy opacity in one hemithorax with preserved vascular shadows Atelectasis Suggested by lung opacification with shift of the mediastinum, hilum, or hemidiaphragm towards the affected area, and compensatory over inflation in the adjacent non-atelectatic lung Pneumothorax Air in the pleural space with no vascular bed surrounding the visceral pleura Bronchospasm Newly detected expiratory wheezing treated with bronchodilators Aspiration pneumonitis Respiratory failure after the inhalation of regurgitated gastric contents PPC: postoperative pulmonary complication; PaO2: partial pressure of oxygen in arterial blood; SpO2: arterial oxyhaemoglobin saturation by pulse oximetry; ALI: acute lung injury; ARDS: adult respiratory distress syndrome; FiO2: fraction of inspired oxygen; PEEP: positive end-expiratory pressure.
mortality rates between countries was built. Adjusted odds ratio (OR) for death in-hospital after surgery for each country was calculated taking UK patients data as reference (OR = 1). A total of 46,539 patients were included in EuSOS, among them 4% died before hospital discharge, a higher rate than the estimates in some European countries ranging overall mortality between 1 and 2% in unselected patients. Moreover, 8% of the study patients were admitted to intensive care unit (ICU) after surgery with a median length of stay in ICU of 1.2 days. Nevertheless, only 5% of patients underwent a planned admission in ICU and 73% of patients who died after surgery were not admitted in ICU. These last results emphasized the lack of anticipation for planned admission in ICU and/or the lack of critical care resources or both. Moreover, mortality rates across the European countries varied widely between 1.2% for Iceland and 21.5% for Latvia with a 3.2% rate for France. In the same manner, adjusted OR (OR = 1 for UK) for inhospital death after surgery varied between 0.44 for Finland to 6.92 for Poland, with an adjusted OR for France of 1.36. Thus, in EuSOS, mortality rate for patients undergoing non-cardiac surgery was higher than expected, suggesting needs to improve care of patients by predefined strategies and optimal critical care resources utilization. As PPCs are one of the most important complications after surgery, a key step toward achieving better management of these potentially life-threatening complications is essential. This issue has to go trough a PPCs risk stratification and a better clinical prediction to implement suitable strategies decreasing this risk. Prospective external validation of a predictive score for postoperative pulmonary complications (PERISCOPE study for Prospective Evaluation of a RIsk Score for postoperative pulmonary COmPlications in Europe) published in 2014 in Anesthesiology [4] is a study performed to test the hypothesis of the geographic transportability of the results from the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) study previously published in 2010 [4]. ARISCAT study addressed the problem of
482
O. Langeron et al. / Annales Franc¸aises d’Anesthe´sie et de Re´animation 33 (2014) 480–483
Table 2 The seven ARISCAT risk predictors and points assigned [7]. Score Age (years) 50 51–80 > 80 Preoperative SpO2 96% 91%–95% 90% Respiratory infection in the last month Preoperative anemia (Hg 10 g/dL) Surgical incision Peripheral Upper abdominal Intrathoracic Duration of surgery (hours) 2 > 2 to 3 >3 Emergency procedure
3 16
8 24 17 11 – – 15 24 – – 16 23 8
Three levels of risk according to the points obtained of this score were considered: < 26 points, which indicated low risk; 26 to 44 points which indicated moderate risk and 45 points which implied high risk. ARISCAT: Assess Respiratory Risk in Surgical Patients in Catalonia; SpO2: arterial oxyhemoglobin saturation by pulse oximetry; Hg: hemoglobin concentration.
differences across different surgical contexts by using a wide range of procedures and patients in a geographically defined (Catalonia), mixed urban-rural practice setting. A clinically practical sevenfactor scoring system (Table 2) to assess risk for a composite PPCs occurrence, i.e. the likelihood of developing any complication in a list of well-defined events, was internally validated. The ARISCAT risk index based on seven objective, easily assessed factors has excellent discriminative ability. The aim of PERISCOPE study was to measure the accuracy of ARISCAT score predictions of PPCs in 63 European centres from 21 countries. Thus, a new patient cohort was prospectively recruited in an observational multicentre design, in 63 European hospitals volunteered to recruit surgical patients during continuous seven-day periods. Cohort splitting was intended to reflect possible case-mix differences that might appear with increased geographical distance from the setting where the ARISCAT model was developed, in case such distances might affect score performance. Three numerically comparable sub-samples were defined, based on their geographical distance from the development population as follows: Spain, Western Europe (WE) and Eastern Europe (EE). Consecutive patients undergoing a non-obstetric in-hospital elective or emergency surgical procedure under general, neuraxial, or plexus block anesthesia were recruited. A total of 5859 surgical patients were recruited and 5099 were included in the data set. In the overall PERISCOPE cohort, 725 PPCs were recorded in 404 patients (7.9% of the 5099 patients studied). In comparison in ARISCAT study, the PPCs rate was 5% [7]. Incidences of pulmonary complications were the following: respiratory failure (241 patients, 4.7%), pleural effusion (159, 3.1%), atelectasis (122, 2.4%), pulmonary infection (120, 24%), bronchospasm (42, 0.8%), pneumothorax (29, 0.6%) and aspiration pneumonitis (12, 0.2%). The median time between surgery and the first PPC recorded was 3 days. In-hospital mortality in the group of patients with at least one PPC (8.3%) was significantly higher than in patients with no PPC (0.2%). The score showed the best discrimination in WE, and the worst discrimination in EE sub-samples. The conclusion of PERISCOPE study was that ARISCAT score could predict quite accurately the PPCs risk in a 3 levels model (low, intermediate and high), but some differences in the score performance were observed according the countries. Consequently, once PPCs risk is estimated in a population, the major issue is to reduce the individual risk at individual level by
acting on factors that are modifiable. The following reported study illustrate this final step of risk decrease and cost killing because a significant reduction of PPCs occurrence. A trial of intraoperative low-tidal volume ventilation in abdominal surgery (known by the acronym IMPROVE) was an important study [5]. This randomized controlled study demonstrated that lung-protective ventilation with a tidal volume of 6– 8 mL/kg of predicted body weight, a PEEP of 6–8 cmH2O and recruitment maneuvers repeated every 30 minutes after tracheal intubation in comparison to non-protective ventilation (tidal volume of 10–12 mL/kg of predicted body weight with no PEEP and no recruitment maneuvers) was able to improve clinical outcomes, with a decreased rate of major pulmonary or extra-pulmonary complications (respectively 10.5% vs 27.5% within the first 7 days) with significantly less requirements of non invasive ventilation or tracheal intubation for postoperative acute respiratory failure. Consequently, by decreasing the PPCs rate and the length of ICU and hospital stay, health care resources were optimized. No significant effect was observed on mortality within the 30 days because the study was not designed for that purpose. One key message of this study is the use of a multifaceted strategy, with more advantage than inconvenient related to the use of ‘‘reasonable’’ implemented ventilation parameters for prophylactic lungprotective ventilation during abdominal surgery in high or intermediate PPCs risk patients. 4. Conclusion PPCs are associated with a higher incidence of life-threatening events and increased health care utilization. Optimization of the care (i.e. ICU) resources and the clinical path of the patient are essential to decrease morbidity and mortality related to PPCs. For example, planned admission in ICU in a high PPCs risk patient could prevent such complication and improve the outcome. Thus, reliable PPCs risk stratification tools are the key issue of clinical decision making in the perioperative period. That is what we learned with the EuSOS and PERISCOPE studies. When the risk is clearly identified related either to the patient according the ARISCAT score and/or to the type of surgery (mainly thoracic and abdominal), low-cost preemptive interventions improve outcomes and new strategies can be developed. The IMPROVE study nicely demonstrated this care optimization with a prophylactic lungprotective ventilation during abdominal surgery. To summarize risk identification and knowledge are the first step of the improving process. Then, risk stratification and new care (multifaceted) strategies implementation allow a decrease in PPCs mortality by optimizing the clinical path of the patient and the care resources. Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. References [1] Pearse RM, Moreno RP, Bauer P, Pelosi P, Metnitz P, Spies C, et al. European Surgical Outcomes Study (EuSOS) group for the Trials groups of the European Society of Intensive Care Medicine and the European Society of Anaesthesiology. Mortality after surgery in Europe: a 7-day cohort study. Lancet 2012;380: 1059–65. [2] Shander A, Fleisher LA, Barie PS, Bigatello LM, Sladen RN, Watson CB. Clinical and economic burden of postoperative pulmonary complications: patient safety summit on definition, risk-reducing interventions, and preventive strategies. Crit Care Med 2011;39:2163–72. [3] McAlister FA, Bertsch K, Man J, Bradley J, Jacka M. Incidence of and risk factors for pulmonary complications after non-thoracic surgery. Am J Respir Crit Care Med 2005;171:514–7.
O. Langeron et al. / Annales Franc¸aises d’Anesthe´sie et de Re´animation 33 (2014) 480–483 [4] Mazo V, Sabate´ S, Canet J, Gallart L, de Abreu MG, Belda J, et al. Prospective external validation of a predictive score for postoperative pulmonary complications. Anesthesiology 2014;121:219–31. [5] Futier E, Constantin JM, Paugam-Burtz C, Pascal J, Eurin M, Neuschwander A, et al. A trial of intraoperative low-tidal-volume ventilation in abdominal surgery. N Engl J Med 2013;369:428–37.
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[6] Canet J, Mazo V. Postoperative pulmonary complications. Minerva Anestesiol 2010;76:138–43. [7] Canet J, Gallart L, Gomar C, Paluzie G, Valles J, Castillo J, et al. Prediction of postoperative pulmonary complications in a population-based surgical cohort. Anesthesiology 2010;113:1338–50.
Monothematic meeting of Sfar 2014
Postoperative pulmonary complications updating§,§§ Complications pulmonaires postope´ratoires : actualisation O. Langeron *, S. Carreira, F. le Sache´, M. Raux Unite´ de surveillance post-interventionnelle et d’accueil des polytraumatise´s, de´partement d’anesthe´sie re´animation, groupe hospitalier Pitie´-Salpeˆtrie`re, Assistance Publique–Hoˆpitaux de Paris, 47-83, boulevard de l’Hoˆpital, 75651 Paris cedex 13, France
A R T I C L E I N F O
A B S T R A C T
Available online 29 August 2014
Postoperative pulmonary complications (PPCs) are a major contributor to the overall risk of surgery. PPCs affect the length of hospital stay and are associated with a higher in-hospital mortality. PPCs are even the leading cause of death either in cardiothoracic surgery but also in non-cardiothoracic surgery. Thus, reliable PPCs risk stratification tools are the key issue of clinical decision making in the perioperative period. When the risk is clearly identified related to the patient according the ARISCAT score and/or the type of surgery (mainly thoracic and abdominal), low-cost preemptive interventions improve outcomes and new strategies can be developed to prevent this risk. The EuSOS, PERISCOPE and IMPROVE studies demonstrated this care optimization by risk identification first, then risk stratification and new care (multifaceted) strategies implementation allowing a decrease in PPCs mortality by optimizing the clinical path of the patient and the care resources. ß 2014 Socie´te´ franc¸aise d’anesthe´sie et de re´animation (Sfar). Published by Elsevier Masson SAS. All rights reserved.
Keywords: Postoperative mortality Postoperative pulmonary complications Risk factors Risk stratification Outcome assessment Preemptive intervention Health care resources
R E´ S U M E´
Mots cle´s : Mortalite´ postope´ratoire Complications pulmonaires postope´ratoires Facteurs de risque Stratification du risque E´valuation du devenir Intervention pre´ventive Ressources de soin
Les complications pulmonaires postope´ratoires (CPP) contribuent grandement au risque pe´riope´ratoire. Les CPPs entraıˆnent une augmentation de la dure´e de se´jour hospitalier et sont associe´es a` une mortalite´ hospitalie`re plus e´leve´e. Les CPP repre´sentent la principale cause de de´ce`s postope´ratoires aussi bien apre`s une chirurgie non cardiothoracique que cardiothoracique. Ainsi, la mise en place d’outils fiables permettant de stratifier le risque de CPP est fondamentale, comme aide pe´riope´ratoire a` la de´cision clinique. En effet, lorsque le risque est clairement identifie´ par l’interme´diaire du score ARISCAT et/ou le ˆ teuses et type de chirurgie (principalement thoracique et abdominale), des mesures pre´ventives peu cou des nouvelles strate´gies peuvent eˆtre instaure´es pour diminuer ce risque de CPP. Les e´tudes EuSOS, PERISCOPE et IMPROVE ont de´montre´ que l’optimisation du soin avec l’identification et la stratification du risque permettaient la mise en place de nouvelles strate´gies (multidirectionnelles) de soins permettant de diminuer la mortalite´ des CPP en optimisant le chemin clinique du patient et les ressources de soin. ß 2014 Socie´te´ franc¸aise d’anesthe´sie et de re´animation (Sfar). Publie´ par Elsevier Masson SAS. Tous droits re´serve´s.
1. Introduction
§
Article presented at Monothematic meeting of Sfar (Socie´te´ franc¸aise d’anesthe´sie et de re´animation): ‘‘Perioperative ventilation’’, Paris, May 21, 2014. §§ This article is published under the responsibility of the Scientific Committee of the ‘‘Journe´e Monothe´matique 2014 de la Sfar’’. The editorial board of the Annales franc¸aises d’anesthe´sie et de re´animation was not involved in the conception and validation of its content. * Corresponding author. E-mail address: [email protected] (O. Langeron).
Mortality after non-cardiac surgery still remains an important issue in Europe, with an overall mortality rate of 4%, higher than the 2% rate expected [1]. In addition, important variations between countries were observed, highlighting the importance of the clinical path of the patients according to their perioperative risk and their clinical status [1]. Postoperative pulmonary complications (PPCs) are a major contributor to the overall risk of surgery. PPCs affect the length of hospital stay and are associated with a
http://dx.doi.org/10.1016/j.annfar.2014.07.741 0750-7658/ß 2014 Socie´te´ franc¸aise d’anesthe´sie et de re´animation (Sfar). Published by Elsevier Masson SAS. All rights reserved.
O. Langeron et al. / Annales Franc¸aises d’Anesthe´sie et de Re´animation 33 (2014) 480–483
higher in-hospital mortality with an estimate of 4.8 million additional days of hospitalization and 46,200 additional deaths in the United States [2]. Thus, PPCs are the leading cause of death either in cardiothoracic surgery but also in non-cardiothoracic surgery [3]. Moreover, PPCs increase financial outcomes of health care, like in the United States with an annual reported economic burden of several billions (US dollars) [2]. Prediction of the perioperative risk, including PPCs is an important issue to decrease the postoperative morbidity, mortality and the surgical hospitalization cost. Some important recent studies are dedicated to this topic and have been reported in thematic day dedicated to perioperative ventilation organized by the Sfar (Socie´te´ franc¸aise d’anesthe´sie et de re´animation) held in Paris on May 2014 the 21st. In this updating, we will first give actual definitions of PPCs and discuss studies improving our knowledge of PPCs: Mortality after surgery in Europe: a 7-day cohort study published in 2012 in Lancet Journal [1]; prospective external validation of a predictive score for postoperative pulmonary complications (PERISCOPE study) published in 2014 in Anesthesiology [4]; a trial of intraoperative lowtidal volume ventilation in abdominal surgery published in 2013 in the New England Journal of Medecine [5]. 2. Definitions of PPCs There is no standard definition of PPCs. They can be broadly defined as conditions affecting the respiratory tract that can adversely influence the clinical course of a patient after surgery. Consequently, incidence rates could vary dramatically from 2% to 40% [6]. Nevertheless, PPCs definitions usually include respiratory failure, tracheal reintubation within 48 hours, weaning failure, pneumonia, atelectasis, bronchospasm, exacerbation of chronic obstructive pulmonary disease, pneumothorax, pleural effusion, and various forms of upper airway obstruction. PPCs have a multifactorial etiology and a lot of perioperative risk factors [6]. One approach to standardize the PPCs could be a physiopathological definition with postoperative decreased functional residual capacity and total lung capacity that result in ventilation-perfusion mismatch and hypoxemia. In clinical studies, postoperative pulmonary complication is defined as the occurrence of at least one postoperative respiratory event in a composite list of inhospital fatal or non-fatal PPCs (Table 1) [4]. Consequently, incidence of PPCs could vary a lot between surgical procedures. For example, thoracic surgery has much higher PPCs incidence (37.8%) than upper abdominal (12.2%) or peripheral (2.2%) surgery [7]. 3. Studies improving our knowledge of PPCs We will illustrate the impact of PPCs according to 3 studies. The main issue of a better knowledge of PPCs occurrence is the necessity to more precisely assess the respiratory risk in surgical patients and thereafter to decrease PPCs risk with preventing procedures. Mortality after surgery in Europe: a 7-day cohort study, named EuSOS study for European surgical outcome study published in 2012 in Lancet Journal [1] is a major study reminding us that variations in postoperative mortality are related to the clinical path of the patient, i.e. with critical care resources. EuSOS was designed to assess outcomes after surgery in Europe, especially to describe first mortality rates and second patterns of critical care resource use for patients undergoing non-cardiac surgery across 28 European nations. A 7-day cohort study collecting data for consecutive patients in selected centres (498 hospitals) either for scheduled or emergency surgery was performed in April 2011. A multilevel logistic regression model to adjust difference in
481
Table 1 PPC: a composite defined as any one or more of a list of in-hospital fatal or non-fatal postoperative PPCs [4]. Respiratory failure (mild, intermediate, or severe) Mild: PaO2 < 60 mmHg or SpO2 < 90% in room air but responding to supplemental oxygen (excluding hypoventilation) Intermediate: need for non-invasive or invasive mechanical ventilation or a PaO2 < 60 mmHg or SpO2 < 90% Severe (ALI/ARDS): need for invasive mechanical ventilation and PaO2/FiO2 < 300 mmHg regardless the level of PEEP Suspected pulmonary infection, in a patient on antibiotics, meeting at least one of the following criteria New or changed sputum New or changed lung opacities on chest x-ray when clinically indicated Temperature > 38.3 8C White cell count > 12,000/mm3 Pleural effusion Chest X-ray demonstrating blunting of the costophrenic angle, loss of the sharp silhouette of the ipsilateral hemidiaphragm (in upright position), evidence of displacement of adjacent anatomical structures, or (in supine position) a hazy opacity in one hemithorax with preserved vascular shadows Atelectasis Suggested by lung opacification with shift of the mediastinum, hilum, or hemidiaphragm towards the affected area, and compensatory over inflation in the adjacent non-atelectatic lung Pneumothorax Air in the pleural space with no vascular bed surrounding the visceral pleura Bronchospasm Newly detected expiratory wheezing treated with bronchodilators Aspiration pneumonitis Respiratory failure after the inhalation of regurgitated gastric contents PPC: postoperative pulmonary complication; PaO2: partial pressure of oxygen in arterial blood; SpO2: arterial oxyhaemoglobin saturation by pulse oximetry; ALI: acute lung injury; ARDS: adult respiratory distress syndrome; FiO2: fraction of inspired oxygen; PEEP: positive end-expiratory pressure.
mortality rates between countries was built. Adjusted odds ratio (OR) for death in-hospital after surgery for each country was calculated taking UK patients data as reference (OR = 1). A total of 46,539 patients were included in EuSOS, among them 4% died before hospital discharge, a higher rate than the estimates in some European countries ranging overall mortality between 1 and 2% in unselected patients. Moreover, 8% of the study patients were admitted to intensive care unit (ICU) after surgery with a median length of stay in ICU of 1.2 days. Nevertheless, only 5% of patients underwent a planned admission in ICU and 73% of patients who died after surgery were not admitted in ICU. These last results emphasized the lack of anticipation for planned admission in ICU and/or the lack of critical care resources or both. Moreover, mortality rates across the European countries varied widely between 1.2% for Iceland and 21.5% for Latvia with a 3.2% rate for France. In the same manner, adjusted OR (OR = 1 for UK) for inhospital death after surgery varied between 0.44 for Finland to 6.92 for Poland, with an adjusted OR for France of 1.36. Thus, in EuSOS, mortality rate for patients undergoing non-cardiac surgery was higher than expected, suggesting needs to improve care of patients by predefined strategies and optimal critical care resources utilization. As PPCs are one of the most important complications after surgery, a key step toward achieving better management of these potentially life-threatening complications is essential. This issue has to go trough a PPCs risk stratification and a better clinical prediction to implement suitable strategies decreasing this risk. Prospective external validation of a predictive score for postoperative pulmonary complications (PERISCOPE study for Prospective Evaluation of a RIsk Score for postoperative pulmonary COmPlications in Europe) published in 2014 in Anesthesiology [4] is a study performed to test the hypothesis of the geographic transportability of the results from the Assess Respiratory Risk in Surgical Patients in Catalonia (ARISCAT) study previously published in 2010 [4]. ARISCAT study addressed the problem of
482
O. Langeron et al. / Annales Franc¸aises d’Anesthe´sie et de Re´animation 33 (2014) 480–483
Table 2 The seven ARISCAT risk predictors and points assigned [7]. Score Age (years) 50 51–80 > 80 Preoperative SpO2 96% 91%–95% 90% Respiratory infection in the last month Preoperative anemia (Hg 10 g/dL) Surgical incision Peripheral Upper abdominal Intrathoracic Duration of surgery (hours) 2 > 2 to 3 >3 Emergency procedure
3 16
8 24 17 11 – – 15 24 – – 16 23 8
Three levels of risk according to the points obtained of this score were considered: < 26 points, which indicated low risk; 26 to 44 points which indicated moderate risk and 45 points which implied high risk. ARISCAT: Assess Respiratory Risk in Surgical Patients in Catalonia; SpO2: arterial oxyhemoglobin saturation by pulse oximetry; Hg: hemoglobin concentration.
differences across different surgical contexts by using a wide range of procedures and patients in a geographically defined (Catalonia), mixed urban-rural practice setting. A clinically practical sevenfactor scoring system (Table 2) to assess risk for a composite PPCs occurrence, i.e. the likelihood of developing any complication in a list of well-defined events, was internally validated. The ARISCAT risk index based on seven objective, easily assessed factors has excellent discriminative ability. The aim of PERISCOPE study was to measure the accuracy of ARISCAT score predictions of PPCs in 63 European centres from 21 countries. Thus, a new patient cohort was prospectively recruited in an observational multicentre design, in 63 European hospitals volunteered to recruit surgical patients during continuous seven-day periods. Cohort splitting was intended to reflect possible case-mix differences that might appear with increased geographical distance from the setting where the ARISCAT model was developed, in case such distances might affect score performance. Three numerically comparable sub-samples were defined, based on their geographical distance from the development population as follows: Spain, Western Europe (WE) and Eastern Europe (EE). Consecutive patients undergoing a non-obstetric in-hospital elective or emergency surgical procedure under general, neuraxial, or plexus block anesthesia were recruited. A total of 5859 surgical patients were recruited and 5099 were included in the data set. In the overall PERISCOPE cohort, 725 PPCs were recorded in 404 patients (7.9% of the 5099 patients studied). In comparison in ARISCAT study, the PPCs rate was 5% [7]. Incidences of pulmonary complications were the following: respiratory failure (241 patients, 4.7%), pleural effusion (159, 3.1%), atelectasis (122, 2.4%), pulmonary infection (120, 24%), bronchospasm (42, 0.8%), pneumothorax (29, 0.6%) and aspiration pneumonitis (12, 0.2%). The median time between surgery and the first PPC recorded was 3 days. In-hospital mortality in the group of patients with at least one PPC (8.3%) was significantly higher than in patients with no PPC (0.2%). The score showed the best discrimination in WE, and the worst discrimination in EE sub-samples. The conclusion of PERISCOPE study was that ARISCAT score could predict quite accurately the PPCs risk in a 3 levels model (low, intermediate and high), but some differences in the score performance were observed according the countries. Consequently, once PPCs risk is estimated in a population, the major issue is to reduce the individual risk at individual level by
acting on factors that are modifiable. The following reported study illustrate this final step of risk decrease and cost killing because a significant reduction of PPCs occurrence. A trial of intraoperative low-tidal volume ventilation in abdominal surgery (known by the acronym IMPROVE) was an important study [5]. This randomized controlled study demonstrated that lung-protective ventilation with a tidal volume of 6– 8 mL/kg of predicted body weight, a PEEP of 6–8 cmH2O and recruitment maneuvers repeated every 30 minutes after tracheal intubation in comparison to non-protective ventilation (tidal volume of 10–12 mL/kg of predicted body weight with no PEEP and no recruitment maneuvers) was able to improve clinical outcomes, with a decreased rate of major pulmonary or extra-pulmonary complications (respectively 10.5% vs 27.5% within the first 7 days) with significantly less requirements of non invasive ventilation or tracheal intubation for postoperative acute respiratory failure. Consequently, by decreasing the PPCs rate and the length of ICU and hospital stay, health care resources were optimized. No significant effect was observed on mortality within the 30 days because the study was not designed for that purpose. One key message of this study is the use of a multifaceted strategy, with more advantage than inconvenient related to the use of ‘‘reasonable’’ implemented ventilation parameters for prophylactic lungprotective ventilation during abdominal surgery in high or intermediate PPCs risk patients. 4. Conclusion PPCs are associated with a higher incidence of life-threatening events and increased health care utilization. Optimization of the care (i.e. ICU) resources and the clinical path of the patient are essential to decrease morbidity and mortality related to PPCs. For example, planned admission in ICU in a high PPCs risk patient could prevent such complication and improve the outcome. Thus, reliable PPCs risk stratification tools are the key issue of clinical decision making in the perioperative period. That is what we learned with the EuSOS and PERISCOPE studies. When the risk is clearly identified related either to the patient according the ARISCAT score and/or to the type of surgery (mainly thoracic and abdominal), low-cost preemptive interventions improve outcomes and new strategies can be developed. The IMPROVE study nicely demonstrated this care optimization with a prophylactic lungprotective ventilation during abdominal surgery. To summarize risk identification and knowledge are the first step of the improving process. Then, risk stratification and new care (multifaceted) strategies implementation allow a decrease in PPCs mortality by optimizing the clinical path of the patient and the care resources. Disclosure of interest The authors declare that they have no conflicts of interest concerning this article. References [1] Pearse RM, Moreno RP, Bauer P, Pelosi P, Metnitz P, Spies C, et al. European Surgical Outcomes Study (EuSOS) group for the Trials groups of the European Society of Intensive Care Medicine and the European Society of Anaesthesiology. Mortality after surgery in Europe: a 7-day cohort study. Lancet 2012;380: 1059–65. [2] Shander A, Fleisher LA, Barie PS, Bigatello LM, Sladen RN, Watson CB. Clinical and economic burden of postoperative pulmonary complications: patient safety summit on definition, risk-reducing interventions, and preventive strategies. Crit Care Med 2011;39:2163–72. [3] McAlister FA, Bertsch K, Man J, Bradley J, Jacka M. Incidence of and risk factors for pulmonary complications after non-thoracic surgery. Am J Respir Crit Care Med 2005;171:514–7.
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