Revised ESC/ESA Guidelines on non-cardiac surgery: cardiovascular assessment and management. Implications for preoperative clinical evaluation.

Each year, an increasing number of elderly patients with cardiovascular disease undergoing non-cardiac surgery require careful perioperative management to minimize the perioperative risk. Perioperative cardiovascular complications are the strongest predictors of morbidity and mortality after major non-cardiac surgery. A Joint Task Force of the European Society of Cardiology (ESC) and the European Society of Anaesthesiology (ESA) has recently published revised Guidelines on the perioperative cardiovascular management of patients scheduled to undergo non-cardiac surgery, which represent the official position of the ESC and ESA on various aspects of perioperative cardiac care. According to the Guidelines effective perioperative cardiac management includes preoperative risk stratification based on preoperative assessment of functional capacity, type of surgery, cardiac risk factors, and cardiovascular function. The ESC/ESA Guidelines discourage indiscriminate routine preoperative cardiac testing, because it is time- and cost-consuming, resource-limiting, and does not improve perioperative outcome. They rather emphasize the importance of individualized preoperative cardiac evaluation and the cooperation between anesthesiologists and cardiologists. We summarize the relevant changes of the 2014 Guidelines as compared to the previous ones, with particular emphasis on preoperative cardiac testing.

Flow-controlled expiration: a novel ventilation mode to attenuate experimental porcine lung injury.

BACKGROUND: Whereas the effects of various inspiratory ventilatory modifications in lung injury have extensively been studied, those of expiratory ventilatory modifications are less well known. We hypothesized that the newly developed flow-controlled expiration (FLEX) mode provides a means of attenuating experimental lung injury. METHODS: Experimental acute respiratory distress syndrome was induced by i.v. injection of oleic acid in 15 anaesthetized and mechanically ventilated pigs. After established lung injury ([Formula: see text]ratio <27 kPa), animals were randomized to either a control group receiving volume-controlled ventilation (VCV) or a treatment group receiving VCV with additional FLEX (VCV+FLEX). At predefined times, lung mechanics and oxygenation were assessed. At the end of the experiment, the pigs were killed, and bronchoalveolar fluid and lung biopsies were taken. Expression of inflammatory cytokines was analysed in lung tissue and bronchoalveolar fluid. Lung injury score was determined on the basis of stained tissue samples. RESULTS: Compared with the control group (VCV; n=8), the VCV+FLEX group (n=7) demonstrated greater dynamic lung compliance and required less PEEP at comparable [Formula: see text] (both P<0.05), had lower regional lung wet-to-dry ratios and lung injury scores (both P<0.001), and showed less thickening of alveolar walls (an indicator of interstitial oedema) and de novo migration of macrophages into lung tissue (both P<0.001). CONCLUSIONS: The newly developed FLEX mode is able to attenuate experimental lung injury. FLEX could provide a novel means of lung-protective ventilation.

Combined paravertebral and intrathecal vs thoracic epidural analgesia for post-thoracotomy pain relief.

BACKGROUND: Although thoracic epidural analgesia (TEA) is considered the gold standard for post-thoracotomy pain relief, thoracic paravertebral block (PVB) and intrathecal opioid (ITO) administration have also been shown to be efficacious. We hypothesized that the combination of PVB and ITO provides analgesia comparable with that of TEA. METHODS: After local ethics committee approval, 84 consecutive patients undergoing open thoracic procedures were randomized to the TEA (ropivacaine 0.2%+sufentanil) or the PVB (ropivacaine 0.5%)+ITO (sufentanil+morphine) group. The primary endpoints were pain intensities at rest and during coughing/movement at 1, 2, 4, 8, 12, 24, 48, and 72 h after operation assessed by visual analogue scale (VAS) score. Data were analysed by multivariate analysis (anova; P<0.05). RESULTS: Patient and surgical characteristics were comparable between the groups. The mean and maximal VAS scores were lower in the TEA (n=43) than in the PVB+ITO group (n=37) at several time points at rest (P<0.026) and during coughing/movement (P<0.021). However, in the PVB+ITO group, the mean VAS scores never exceeded 1.9 and 3.5 at rest and during coughing/movement, respectively; and the maximal differences between the groups (TEA vs PVB+ITO) in the maximal VAS scores were only 1.2 (3.4 vs 4.6) at rest, and 1.3 (4.4 vs 5.7) during coughing/movement. CONCLUSIONS: Although VAS scores were statistically lower in the TEA compared with the PVB+ITO group at some observation points, the differences were small and of questionable clinical relevance. Thus, combined PVB and ITO can be considered a satisfactory alternative to TEA for post-thoracotomy pain relief. ClinicalTrials.gov number. NCT00493909.

Preoperative cardiac management of the patient for non-cardiac surgery: an individualized and evidence-based approach.

Preoperative cardiovascular management is an essential component of overall perioperative cardiovascular care. It involves preoperative detection and management of cardiovascular disease and prediction of both short- and long-term cardiovascular risk. It thereby not only affects anaesthetic perioperative management (e.g. choice of anaesthetic drug and method, type of monitoring, and postoperative care) but also surgical decision-making (e.g. postponement, modification, and cancellation of surgical procedure). The ultimate goal of preoperative cardiovascular management is to improve overall patient outcome. This requires individualized management. Although preoperative cardiac management has improved during the past decades, we are not yet in the situation where we can accurately predict individual perioperative risk. The individual stress response and the individual interactions between pharmacological intervention and intra- and postoperative risk factors are highly variable. More importantly, preoperative cardiac management is only one aspect of overall perioperative care. There are numerous intra- and postoperative factors which have been shown to affect overall outcome. However, not all of them can reliably be predicted or modified in a way to positively affect overall outcome. Recognition of such factors and aggressive attempts at appropriate intervention may reduce overall risk more than preoperative management in isolation. Without defining and subsequently targeting intra- and postoperative risk factors, the benefit of preoperative cardiac management will be limited.

Neutron computed tomography of rat lungs.

Using conventional methods, three-dimensional imaging of the lung is challenging because of the low contrast between air and tissue and the large differences in dimensions between various pulmonary structures. The small distal airway structures and the high air-to-tissue ratio of lung tissue require an imaging technique which reliably discriminates between air and water. The objective of this study was to assess whether neutron computed tomography would satisfy such a requirement. This method utilizes the unique characteristic of neutrons of directly interacting with the atomic nucleus rather than being scattered by the atomic shell. Neutron computed tomography was tested in rats and allowed differentiation of larger lung structures (e.g., lobes) and distal airways. Airways could be identified reliably down to the sixth bronchial generation, in some cases even down to the tenth generation. The lung could be stabilized for sufficiently long exposure times to achieve an image resolution of 50-60 µm, which is the current physical resolution limit of the neutron computed tomography facility. Neutron computed tomography allowed excellent lung imaging without the need for additional tissue preparation or contrast media. The enhanced structural resolution obtained by applying this new research technique may improve understanding of lung physiology and respiratory therapy.

[Perioperative cardiac care for non-cardiac surgery : 2009 Guidelines of the European Society of Cardiology]. / Perioperatives kardiales Vorgehen bei nichtkardiochirurgischen Eingriffen : Leitlinien 2009 der Europäischen Gesellschaft für Kardiologie.

Since November 2009, the first European guidelines on perioperative cardiac care for non-cardiac surgery have been published by the European Society of Cardiology (ESC) and endorsed by the European Society of Anaesthesiology (ESA). The following article will describe the most important recommendations of these guidelines and discuss the clinically relevant differences to the corresponding recommendations of the current guidelines of the American College of Cardiology (ACC) and the American Heart Association (AHA).

Cricoid pressure: an expert's opinion.

Nearly 40 years ago, cricoid pressure (CP) was introduced into anesthetic practice based on a single small case series that lacked essential information. No randomized controlled trials have since documented any benefit of CP. In addition, numerous surveys have shown that most anesthetists lack adequate theoretical and practical knowledge regarding all aspects of CP. Despite the lack of evidence of its effectiveness, evidence of numerous deleterious effects (the most important being interference with airway management), and documentation of poor practice of the technique, CP is still considered by most anesthetists as a standard of care during rapid sequence induction. However, by using CP we may well be endangering more lives by causing airway problems than we are saving in the hope of preventing pulmonary aspiration. It is dangerous to consider CP to be an effective and reliable measure in reducing the risk of pulmonary aspiration and to become complacent about the many factors that contribute to regurgitation and aspiration. Ensuring optimal positioning and a rapid onset of anesthesia and muscle relaxation to decrease the risk of coughing, straining or regurgitation during the induction of anesthesia are likely more important in the prevention of pulmonary aspiration than CP.

[Cricoid pressure]. / Krikoiddruck.

The vast majority of anaesthetists considers application of cricoid pressure for reasons of patient safety an integral part of rapid sequence induction. Cricoid pressure is applied with the idea that it will prevent regurgitation of gastric content into the pharynx, thereby reducing the incidence of pulmonary aspiration. This review describes the background of the introduction of cricoid pressure into clinical practice, analyzes published data concerning clinical relevance of perioperative pulmonary aspiration and efficacy of cricoid pressure in reducing it, discusses problems associated with its use, assesses knowledge and technical performance of cricoid pressure and presents various recent recommendations regarding application of cricoid pressure. The combination of complete lack of evidence for the efficacy of cricoid pressure in preventing pulmonary aspiration and numerous reports of clinically relevant interference with airway management during its use, seriously question the rationale of recommending the general use of cricoid pressure during rapid sequence induction.

Protective effects of inhaled carbon monoxide in pig lungs during cardiopulmonary bypass are mediated via an induction of the heat shock response.

BACKGROUND: Cardiopulmonary bypass (CPB) may cause acute lung injury leading to increased morbidity and mortality after cardiac surgery. Preconditioning by inhaled carbon monoxide reduces pulmonary inflammation during CPB. We hypothesized that inhaled carbon monoxide mediates its anti-inflammatory and cytoprotective effects during CPB via induction of pulmonary heat shock proteins (Hsps). METHODS: Pigs were randomized either to a control group, to standard CPB, to carbon monoxide+CPB, or to quercetin (a flavonoid and unspecific inhibitor of the heat shock response)+control, to quercetin+CPB, and to quercetin+carbon monoxide+CPB. In the carbon monoxide groups, lungs were ventilated with 250 ppm carbon monoxide in addition to standard ventilation before CPB. At various time points, lung biopsies were obtained and pulmonary Hsp and cytokine concentrations determined. RESULTS: Haemodynamic parameters were largely unaffected by CPB, carbon monoxide inhalation, or administration of quercetin. Compared with standard CPB, carbon monoxide inhalation significantly increased the pulmonary expression of the Hsps 70 [27 (SD 3) vs 69 (10) ng ml(-1) at 120 min post-CPB, P<0.05] and 90 [0.3 (0.03) vs 0.52 (0.05) after 120 min CPB, P<0.05], induced the DNA binding of heat shock factor-1, reduced interleukin-6 protein expression [936 (75) vs 320 (138) at 120 min post-CPB, P<0.001], and decreased CPB-associated lung injury (assessed by lung biopsy). These carbon monoxide-mediated effects were inhibited by quercetin. CONCLUSIONS: As quercetin, a Hsp inhibitor, reversed carbon monoxide-mediated pulmonary effects, we conclude that the anti-inflammatory and protective effects of preconditioning by inhaled carbon monoxide during CPB in pigs are mediated by an activation of the heat shock response.

Electrical impedance tomography to confirm correct placement of double-lumen tube: a feasibility study.

BACKGROUND: Double-lumen tubes (DLTs) are frequently used to establish one-lung ventilation (OLV). Their correct placement is crucial. We hypothesized that electrical impedance tomography (EIT) reliably displays distribution of ventilation between left and right lung and may thus be used to verify correct DLT placement online. METHODS: Regional ventilation was studied by EIT in 40 patients requiring insertion of left-sided DLTs for OLV during thoracic surgery. EIT was recorded during two-lung ventilation before induction of anaesthesia and after DLT placement, and during OLV in the supine and subsequently in the lateral position. EIT measurements were made before and after verification of correct DLT placement by fibreoptic bronchoscopy (FOB). RESULTS: EIT accurately displayed distribution of ventilation between left and right lung online. All cases (n=5) of initially misplaced DLTs in the contralateral right main bronchus were detected by EIT. However, EIT did not allow prediction of FOB-detected endobronchial cuff misplacement requiring DLT repositioning. Furthermore, after DLT repositioning, distribution of ventilation, as assessed by EIT, did not change significantly (all P>0.5). CONCLUSIONS: This study demonstrates that EIT enables accurate display of left and right lung ventilation and, thus, non-invasive online recognition of misplacement of left-sided DLTs in the contralateral main bronchus. However, as distribution of ventilation did not correlate with endobronchial cuff placement, EIT cannot replace FOB in the routine control of DLT position.

[Acute obstruction of the endotracheal tube]. / Akute Obstruktion des endotrachealen Tubus.

Acute occlusion of an endotracheal tube (ETT) is a feared, potentially life-threatening complication of mechanical ventilation. In the presence of a thoracic trauma, a blood clot needs to be taken into consideration as the cause of airway obstruction. This report describes a case of sudden ventilation failure due to acute ETT obstruction by a blood clot caused by intrapulmonary haemorrhaging in a child following multiple trauma accompanied by blunt thoracic trauma in the absence of dyspnoe or haemoptysis.