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.

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.

[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).

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.

Perioperative myocardial infarction--aetiology and prevention.

Perioperative myocardial infarction (PMI) is one of the most important predictors of short- and long-term morbidity and mortality associated with non-cardiac surgery. Prevention of a PMI is thus a prerequisite for an improvement in overall postoperative outcome. The aetiology of PMI is multifactorial. The perioperative period induces large, unpredictable and unphysiological alterations in coronary plaque morphology, function and progression, and may trigger a mismatch of myocardial oxygen supply and demand. With many diverse factors involved, it is unlikely that one single intervention will successfully improve cardiac outcome following non-cardiac surgery. A multifactorial, step-wise approach is indicated. Based on increasing knowledge of the nature of atherosclerotic coronary artery disease, and in view of the poor positive predictive value of non-invasive cardiac stress tests, and the considerable risk of coronary angiography and coronary revascularization in high-risk patients, the paradigm is shifting from an emphasis on extensive non-invasive preoperative risk stratification to a combination of selective non-invasive testing and aggressive pharmacological perioperative therapy. Perioperative plaque stabilization by pharmacological means may be as important in the prevention of PMI as an increase in myocardial oxygen supply or a reduction in myocardial oxygen demand.

Prospective, randomized cost analysis of anesthesia with remifentanil combined with propofol, desflurane or sevoflurane for otorhinolaryngeal surgery.

BACKGROUND: In the era of cost containment, cost analysis should demonstrate the cost-effectiveness of new anesthetic drugs. METHODS: This single-blind, prospective, randomized study compared the costs of three remifentanil (REM)-based anesthetic techniques with a conventional one in 120 patients undergoing otorhinolaryngeal surgery. The patients were randomized (n=30 each group) to either receive a combination of REM with propofol, desflurane or sevoflurane, or a conventional anesthetic with thiopentone, alfentanil, isoflurane and N2O. RESULTS: The costs for anesthetic and nonanesthetic drugs and for disposables were twice as high in the three REM-based groups as in the conventional group (REM/PRO 0.51 Euro;/min, REM/DES 0.42 Euro;/min, and REM/SEVO 0.41 Euro;/min vs. 0.18 Euro;/min in the ALF/ISO/N2O group; P<0.05). Wastage of intravenous drugs accounted for up to 40% of total costs. In all REM groups, early recovery was predictably faster and more complete (P<0.05). Patient satisfaction was equally high (90-97%) in all groups, with less nausea in the REM/PRO group. CONCLUSION: This study demonstrates that REM-based anesthetic techniques are more expensive than a conventional technique using alfentanil, isoflurane and N2O. This is the result of higher costs of anesthetic and nonanesthetic drugs and of disposables. The wastage of intravenous drugs contributes considerably to these costs.

Recovery after anesthesia with remifentanil combined with propofol, desflurane, or sevoflurane for otorhinolaryngeal surgery.

UNLABELLED: Because no previous investigation has directly compared the combination of remifentanil (REM) and a hypnotic with that of REM and the newer volatile anesthetics, we studied recovery characteristics and patient satisfaction after the combination of REM with propofol (PRO), desflurane (DES), or sevoflurane (SEVO). One hundred twenty patients were randomly assigned to receive anesthesia with either REM/PRO, REM/DES, REM/SEVO, or thiopental/alfentanil/isoflurane/N(2)O (control group) for ear, nose, and throat surgery (n = 30 each). In the REM groups, the dosage of PRO (75 microg. kg(-1). min(-1)), and of DES or SEVO (0.5 minimum alveolar anesthetic concentration) was kept unchanged, and REM was titrated to hemodynamic response. The control group was managed according to standard practice. Early recovery (times to eye opening, extubation, and statement of name and date of birth) was predictably faster and more complete in the REM groups compared with the control group. However, late recovery (times to discharge from postanesthesia care unit and hospital) and overall patient satisfaction were not different among groups. No clinically relevant differences existed among the three REM groups. In conclusion, the combination of REM infusion with small-dose DES, SEVO, or PRO is characterized by predictably rapid, early recovery. However, late recovery and patient satisfaction are comparable to a conventional anesthetic technique. IMPLICATIONS: Remifentanil anesthesia, combined with small-dose propofol, desflurane, or sevoflurane, enables predictably fast and smooth early recovery after ear, nose, and throat surgery. Despite such faster, early recovery and less need for postoperative analgesic and antiemetic medication, late recovery was comparable among the remifentanil combination groups and the control group.

Effects of desflurane and propofol on arterial oxygenation during one-lung ventilation in the pig.

BACKGROUND: Desflurane depresses hypoxic pulmonary vasoconstriction (HPV) in vitro. During one-lung ventilation (OLV), HPV may reduce venous admixture and ameliorate the decrease in arterial O2 tension by diverting blood from the non-ventilated to the ventilated lung. Accordingly, this study compares the effects of desflurane with those of propofol on oxygenation during two-lung (TLV) and OLV in vivo. METHODS: Ten pigs (25-30 kg) were premedicated (flunitrazepam 0.4 mg/kg i.m.), anaesthetized (induction: propofol 2 mg/kg i.v.; maintenance: N2O/O2 50%/50%, desflurane 3%, propofol 50 micrograms kg-1 min-1, and vecuronium 0.2 mg kg-1 h-1 i.v.), orally intubated and mechanically ventilated. Femoral arterial and thermodilution pulmonary artery catheters were placed, and the orotracheal tube was replaced by a left-sided 28-Ch double-lumen tube (DLT) via tracheotomy. After DLT placement, N2O and propofol were discontinued, FiO2 was increased to 0.85, and anaesthesia continued randomly with either desflurane (1 MAC) or propofol 200 micrograms kg-1 min-1. Using a cross-over design, in each animal the effects of a), changing from TLV to OLV (left lung) during both desflurane and propofol and b), the effects of changing between the two anaesthetics during OLV were studied. RESULTS: When changing from TLV to OLV, PaO2 decreased more (p < 0.05) during desflurane (mean 75%) than during propofol (mean 60%). Changing between desflurane and propofol during OLV resulted in small but consistent (P < 0.05) increases in PaO2 (mean 15%) during propofol. CONCLUSION: Consistent with in vitro results on HPV, 1 MAC desflurane impaired in vivo oxygenation during OLV more than did propofol.

Oxygen consumption in hemodialysis patients undergoing cardiopulmonary bypass.

OBJECTIVES: Cardiopulmonary bypass (CPB) can be successfully performed in patients on hemodialysis. However, ischemic complications occur more often in these patients. This could partly be because of shunting through the arteriovenous (AV) fistula during CPB, resulting in reduced peripheral flow and oxygen (O2) delivery. Inadequate oxygen delivery during CPB should be reflected in a lower oxygen consumption (VO2) compared with patients without an AV fistula. DESIGN: To test the hypothesis, the authors analyzed VO2 in three groups of patients retrospectively. Group 1 included 14 patients with end-stage renal failure (creatinine level 9.1 +/- 0.3 mg/dL, urea level 126 +/- 8 mg/dL) requiring hemodialysis through an AV fistula. Group 2 included 13 patients with compensated renal insufficiency (creatinine level 3.1 +/- 0.4 mg/dL, urea level 106 +/- 10 mg/dL) without an AV fistula. Group 3 included 14 patients with normal renal function (creatinine level 1.0 +/- 0.1 mg/dL, urea level 44 +/- 4 mg/dL). SETTING: An operating room of a university hospital. PARTICIPANTS: Patients undergoing cardiac surgery requiring CPB. MEASUREMENTS AND MAIN RESULTS: VO2 was calculated from the recorded hemodynamic and blood gas data using standard formulae. Data were analyzed using a two-way analysis of variance with a repeated measurement on one factor. Before undergoing CPB, VO2 was similar in all three groups. VO2 decreased in all three groups during hypothermic CPB (standard flow rate 2.2 L/min/m2, standard temperature 29 degrees C) and returned to prebypass levels during rewarming. There was no difference in VO2 among the three groups during hypothermic CPB or during rewarming. Only base excess decreased more in group 1 patients compared with the other groups (p < 0.001). CONCLUSION: During hypothermic CPB at a flow rate of 2.2 L/min/m2, shunting through an AV fistula is unlikely to lead to decreased VO2 in dialysis patients.

[Arterial hypertension: its impact on perioperative morbidity and mortality]. / Die arterielle Hypertonie: Ihre Bedeutung für die perioperative Morbidität und Mortalität.

Chronic hypertension is associated with structural as well as functional changes of the vasculature, in particular of the coronary, cerebral and renal circulation. It is important to realise that [1] functional changes are often the result of structural changes, [2] the longer lasting the hypertension, the slower and less complete the regression of structural changes, and [3] acute "normalisation" of arterial pressure in long-standing hypertension may initially induce functionally subnormal smooth muscle and/or cardiac activity because the structure of the cardiovascular system is adapted to function at elevated pressures. Despite a multitude of studies, the impact of hypertension on peri-operative morbidity and mortality remains controversial. There are as many studies seeming to suggest that preoperative hypertension correlates with adverse outcome as there are studies that fail to establish such a relationship. When looking at the combined evidence, one is inclined to conclude that hypertension is a predictor of "soft" outcomes (e.g. peri-operative myocardial ischaemia and transient post-operative neurologic deficit) rather than an independent predictor of "hard" outcomes (e.g. unstable angina, myocardial infarction and cardiac death). In view of lack of convincing outcome data, it is impossible to recommend a generally acceptable management strategy for the hypertensive patient. Although, in general, a gradual reduction of blood pressure over a period of weeks to months is the optimal therapeutic approach, we will be hard-pressed delaying surgery for the sole purpose of "better blood pressure control". With full appreciation and detailed knowledge of the pathophysiology of hypertension, combined with sophisticated haemodynamic monitoring and interventions in the peri-operative period, acutely anaesthetising an inadequately treated hypertensive patient will probably not adversely affect his outcome. Delaying surgery for additional work-up may possibly improve outcome in patients with target organ disease, evidence of secondary hypertension, in the most severe forms of hypertension or sudden-onset hypertension.

Effects of dopamine on oxygen consumption and gastric mucosal blood flow during cardiopulmonary bypass in humans.

We investigated the effects of flow rate and dopamine on systemic oxygen delivery (DO2) oxygen consumption (VO2) and gastric mucosal microcirculatory blood flow (gMCF), measured by laser Doppler flowmetry in 12 patients undergoing mild hypothermic (34 degrees C) cardiopulmonary bypass (CPB). The first intervention comprised increasing CPB flow rates from 2.4 to 3.0 litre min-1 m-2, and the second intervention administering dopamine 6 micrograms kg-1 min-1. Measurements were made before and 10 min after the start of one of the two interventions. The heart remained in cardioplegic arrest throughout the study. There were no significant differences in variables between the two baseline measurements preceding the interventions. The increase in CPB flow rate increased DO2 and gMCF without affecting VO2. At constant flow rate, dopamine also increased gMCF with no change in VO2, DO2 or mean arterial pressure. Our data suggested that dopamine had no flow-independent effect on VO2 and that it increased gMCF during constant flow hypothermic CPB.