Perioperative Anämietoleranz

Zusammenfassung Die zu erwartende Kostensteigerung im Transfusionswesen erhöht den sozioökonomischen Stellenwert der Entwicklung institutionsspezifischer Transfusionsprogramme. Ein wesentlicher Bestandteil hierbei ist – neben einer schonenden Operationstechnik und der konsequenten perioperativen Anwendung fremdblutsparender Maßnahmen – die Ausschöpfung der natürlichen Anämietoleranz des menschlichen Organismus. Im vorliegenden Beitrag werden die Mechanismen, Einflussgrößen und Grenzen dieser Anämietoleranz für den Gesamtorganismus und für einzelne Organsysteme zusammengefasst und die sich daraus ergebende Indikation zur Erythrozytentransfusion abgeleitet. Die derzeit geltenden Empfehlungen decken sich dahingehend, dass bis zu einer Hämoglobinkonzentration von 10 g/dl (6,21 mmol/l) auch bei alten Patienten oder kardiopulmonalen Begleiterkrankungen eine perioperative Transfusion in der Regel nicht notwendig ist und bei jungen, gesunden Patienten ohne kardiopulmonale Vorerkrankungen (einschließlich Schwangeren und Kindern) erst ab <6 g/dl (<3,72 mmol/l) notwendig wird. Auch beatmete Intensivpatienten mit Polytrauma und Sepsis scheinen nicht von einer Transfusion auf eine Hämoglobinkonzentration >9 g/dl (>5,59 mmol/l) zu profitieren. Bei massiven Blutverlusten und diffuser Blutungsneigung scheint ein Wert von 10 g/dl (6,21 mmol/l) zur Stabilisierung der Blutgerinnung beizutragen.Dieser Beitrag beruht auf einem ursprünglich in Der Anästhesist erschienenen Leitthema.     

Perioperative Anämie

Anemia is a frequent finding, particularly in the elderly population, and usually indicative of a serious disease. The main causes of preoperative anemia are acute or chronic hemorrhage, iron deficiency, renal insufficiency, inflammatory and neoplastic diseases. A preexisting mild anemia may be enhanced or unmasked by surgically induced bleeding or repeated diagnostic phlebotomies, and by a postoperative erythropoietic dysfunction caused by the surgical trauma, irrespective of any hemorrhage. Low hemoglobin values are associated with a distinct increase of mortality and morbidity, both in the normal population and perioperatively and in the critically ill patients. The anemia-associated risk is exacerbated by preexisting cardiovascular disease, important intraoperative blood loss and advanced age. In contradiction to established therapeutical concepts, the administration of allogeneic blood beyond hemoglobin levels of 8-10 g/dl has not been found to decrease perioperative or intensive care morbidity or mortality. Rather, in addition to the inherent long-term risks of transfusions, a liberal transfusion strategy seems to increase the incidence of postoperative complications. Thus, current transfusion guidelines tend to be interpreted in an increasingly restrictive manner. Depending on the urgency of the clinical situation, the primary goal should be to diagnose and treat the underlying disease, rather than to focus on the symptom anemia. Time permitting, the patient's cardiovascular and pulmonary status should be optimized preoperatively. Furthermore, iron should be substituted to treat and prevent deficiency. Recombinant human erythropoietin has successfully been used to treat anemia of chronic renal failure and chronic disease, as well as in the perioperative and intensive care setting, and to support the efficiency of autologous programs.     

Perioperative Betreuung von Palliativpatienten durch den Anästhesisten

Anesthetists will encounter palliative patients in the daily routine as palliative patients undergo operations and interventions as well, depending on the state of the disease. The first challenge for anesthetists will be to recognize the patient as being palliative. In the course of further treatment it will be necessary to address the specific problems of this patient group. Medical problems are optimized symptom control and the patient’s pre-existing medication. In the psychosocial domain, good communication skills are expected of anesthetists, especially during the preoperative interview. Ethical conflicts exist with the decision-making process for surgery and the handling of perioperative do-not-resuscitate orders. This article addresses these areas of conflict and the aim is to enable anesthetists to provide the best possible perioperative care to this vulnerable patient group with the goal to maintain quality of life and keep postoperative recovery as short as possible.     

Perioperative Anämie – Toleranz oder Therapie?

Ohne Zusammenfassung     

Perioperative Myokardischämie

Die Anaesthesiologie - Zukünftig wird sich eine zunehmende Zahl älterer Patienten mit signifikanten Begleiterkrankungen auch größeren, chirurgischen Eingriffen unterziehen...     

Perioperative akute Nierenschädigung

Die Anaesthesiologie - Die akute Nierenschädigung („acute kidney injury“, AKI) ist eine häufige Komplikation im perioperativen Bereich und geht mit einer erhöhten...     

Die Anästhesie der Anästhesie

Viewed from a cultural-ethical perspective, anesthesiology can be understood as a comprehensive concept of medicine in general. As such it contains two dilemmas: very often pain must be inflicted in order to alleviate pain and this can only be done by somebody who is himself relatively free of pain. The necessary apathy or anesthesia of the anesthetist is correlated with a general twentieth century-type of perception: the cool observer. Nevertheless, it is also a modern variation of the original religious constellation of the priest in relationship to the sick person. Curing occurs by representation. The weak self of the sick person is able to take over the strong self, represented by the therapist. In twentieth century art and literature this process of self-therapy by representation was often illustrated. On the background of a phenomenological philosophy that process can be understood as the regaining of a balance between body and soul. In the psalms of the biblical Book of Job there a variety of fundamental forms of pain which may be helpful even in this secular age.     

Perioperative Myokardschäden bei nichtkardiochirurgischen Patienten

Perioperative myocardial damage occurs with a high incidence depending on the operative procedure and the patients examined and is considered to be among the most relevant risk factors for increased perioperative morbidity and mortality in patients undergoing non-cardiac surgery. The pathophysiology of myocardial damage in the perioperative period is still not well understood. Both ischemia with and without acute coronary occlusion and non-ischemic stimuli can put a substantial strain on the heart in the perioperative period. However, in many cases the clinical presentation does not allow a clear differentiation between ischemic and non-ischemic myocardial damage. In the majority of cases perioperative myocardial infarctions occur with only mild or even without any clinical symptoms. This is probably due to a considerable difference in phenotype and pathophysiology between perioperative and non-perioperative myocardial infarctions. As a result of this unexplained etiology of perioperative myocardial infarction it remains an open question whether the contemporary diagnostic and therapeutic recommendations for the acute coronary syndrome can be extrapolated to the perioperative situation. The present review reflects the current state of knowledge and presents an optional approach to the diagnosis and therapy of perioperative myocardial injury.     

An Approach to Standard Perioperative Transthoracic Echocardiography Practice for Anesthesiologists—Perioperative Transthoracic Echocardiography Protocols

The use of intraoperative transesophageal echocardiography (TEE) has become the standard of care for most cardiac surgical procedures. There are guidelines established for training, practice, and quality improvement in perioperative TEE by the joint efforts of the American Society of Echocardiography and Society of Cardiovascular Anesthesiologists. Cardiac point-of-care ultrasound (POCUS) increasingly is being incorporated into anesthesiologists’ training and practice. While a special “certification in Critical Care Echocardiography” was created by the National Board of Echocardiography in 2019, there currently exist no guidelines for training, certification, and practice of perioperative TTE by anesthesiologists. In this review, the authors describe the categories, indications and applications of perioperative TTE and provide a recommended sequence for performing an examination tailored to the evaluation of perioperative patients. Although the authors describe a protocol utilized at their institution, there are no standards described in the literature for PTTE. Cardiac anesthesiologists and cardiac anesthesia societies (Society of Cardiovascular Anesthesiologists, European Association of Cardiothoracic Anesthesiologists) must come forward to establish standards working in collaboration with echocardiography societies (American Society of Echocardiography, European Society of Cardiology).     

Perioperative Lebensqualität der Patienten mit Bauchaortenaneurysma

Patient satisfaction plays an increasing part in the analysis of the outcome of medical treatment. The aim of the study was to compare health-related quality of life in patients with abdominal aortic aneurysm after endovascular or conventional surgery. A total of 40 patients were included (20 treated by endovascular and 20 by conventional surgery). A questionnaire with 28 items similar to the SF-36 was answered during scheduled appointments. On the third postoperative day, the conventionally treated patients were more frequently confined to bed (80% vs. 32%) and complained of intervention-related pain (90% vs. 42%) and incisional pain (26% vs. 15%); 55% of the patients suffered from obstipation (vs. 5% of the endovascular group). Furthermore, the preoperative psychological stress seemed to be intensified. In comparable percentage, both the endovascular and conventionally treated patients were limited in social activities perioperatively. Sexual dysfunction was more frequent in the conventional group (33% vs. 13% three months postoperative). In addition, the conventionally treated patients were more limited in their physical activities (25% vs. 40%) and had more fear of ambulation (35% vs. 6%). The patients treated by an endovascular approach complained about frequent examinations (39% vs. 5%) that were often related to X-ray exposure (67% vs. 20%). All of the conventionally operated patients had a sense of improvement (vs. 89% of the endovascular group); nevertheless only 28% felt completely healthy, compared to 11% of the endovascular treated patients. Advantages of the endovascular treated patients were ”short hospital stay”, ”decreased pain”, ”smaller scars”, and a ”shorter confinement to bed”. After intervention the conventionally treated patients were more limited in almost all quality-of-life aspects. After 3 months, differences between the groups decreased except for sexual dysfunction and limited physical activities. The patients treated by endovascular surgery complained more about frequent X-ray examinations than the conventionally treated group.     

Perioperative kardiovaskuläre Morbidität und Letalität bei nichtherzchirurgischen Eingriffen

Die Anaesthesiologie - Die perioperative Morbidität und Letalität haben sich in den letzten Jahrzehnten u. a. durch fortschrittliche Operationstechniken, umfangreichere...     

Perioperative Überwachung der Hämoglobinfraktionen bei homozygoter Sichelzellanämie

This case report presents the perioperative management of double-sided hip arthroplasty in a patient (female, 25 years old) homozygous for sickle cell anemia (SS). The fraction of sickle hemoglobin (Hb S) to total hemoglobin was monitored with an automated cation exchange microcolumn chromatography. The main purpose of ion exchange chromatography is to measure glycated hemoglobin A (HbA1c) in diabetic patients. Furthermore, as a by-product, this test enables the quantitative assessment of aberrant hemoglobin molecules such as sickle cell hemoglobin Hb S with sufficient precision and selectivity. The standard method, hemoglobin-electrophoresis is more complicated and not generally available. For the perioperative estimation of the risk for sickle cell related complications and as a guide for transfusion therapy, knowledge of preoperative Hb S level is essential. In this case report, the clinical use of a rapid laboratory test at low costs with common equipment in a patient with known homozygous sickle cell anemia is demonstrated.     

Volatile Anästhetika

None of the currently available inhaled anesthetics has all of the properties of an "ideal" inhaled agent. The exceptionally low solubility of desflurane and sevoflurane offers a significantly greater precision of control over maintenance of anesthesia and a potential for a more rapid recovery from anesthesia than other inhaled anesthetics. Sevoflurane appears to offer some advantages regarding cardiovascular stability. Products of metabolism or degradation can be associated with potential organ-specific toxic effects. Renal toxicity is discussed for enflurane and sevoflurane. Breakdown products of volatile agents with carbon dioxide absorbents have to be mentioned especially for sevoflurane (compound A) and desflurane (CO). In contrast to intravenous anesthetics, volatile anesthetics are associated with cardio- and cerebroprotection.     

Patientenorientierte Anästhesie

Goals of this study were to quantify patients' preferences for anaesthesia care and to identify what they know about various tasks of an anaesthetist. On the day before surgery, 122 patients scheduled for elective procedures were interviewed using a structured questionnaire. A reliable pain relieve and unawareness as well as stable vital functions have priority in patients' preferences. Patients are also concerned with good postoperative pain relieve and the avoidance of nausea and vomiting. Not important are short preoperative soberness, rapid awakening and initial wide awakeness. Not informed about typical tasks of an anaesthetist are 28-51% of the patients. In order to obtain maximum patient satisfaction, a thorough education plus further continuous training are the essential items for a patient orientated health care management in anaesthesia, along with good medical and technical equipment. The wide spectrum of tasks of an anaesthetist must be better represented in order to strengthen the position of anaesthesia in the competition for rare resources. A postoperative visit, which is judged of 77% of the patients as important, offers a beginning.     

Inhalative Anästhetika

Inhaled anesthetics are inhaled via the lungs. They subsequently pass through the alveolocapillary membrane and diffuse into the blood to finally target the central nervous system and induce anesthesia. This principle of anesthesia induction was first described for diethylether in 1847. Nevertheless, the use of diethylether for anesthesia is obsolete and even the use of nitrous oxide (introduced for anesthesia in 1847) is declining in Germany. Almost all modern volatile anesthetics are halogenated methylethylethers in which fluorine is used as a halogen. All of these anesthetics depress myocardial contractility and induce hypotension. Depression of CO₂ and hypoxia-induced respiration are other serious side effects. Further side effects are liver and kidney related but they are rare and not induced by anesthetics per se but preferentially by toxic metobolites. Another promising inhalative anesthetic is xenon which fulfils many aspects of an ideal inhalative anesthetic.     

Kombinierte Anästhesieverfahren

The additive properties of general and regional anesthetic techniques are brought together in combined anesthesia to minimise side effects of the individual techniques. Despite a wide experience with both used as single anesthetic techniques, no definite recommendations regarding indications, general contraindications and procedure exist for their combination. Beneficial effects on haemodynamics, respiratory function, intestinal motility and postoperative stress response have been demonstrated for a combination of general anesthesia and thoracic epidural anesthesia (TEA). In addition TEA is favourable in the management of postoperative pain, which has advantageous effects on convalescence especially in a high risk patient group. Nevertheless, until now no reduction of perioperative morbidity and mortality has been demonstrated. Since the combination of two anesthesia techniques theoretically increases the rate of complication, the expected benefit for the patient must predominate. To estimate the risks and benefits of combined anesthesia, the anesthesiologist must be familiar with each single method, as well as with the synergistic effects of both techniques in order to evaluate the individual indication.