Surgical Intensive Care Medicine Research Articles

Ethische Grenzsituationen in der chirurgischen Intensivmedizin - Bedeutung einer ethischen Fallberatung

In surgical intensive care medicine an increase in ethical conflicts regarding treatment plans has been observed due to marked changes in medical possibilities and social epidemiology resulting in intensive care treatment of old and oldest patients following surgery, trauma or transplantation. Without ethical support, physicians, nurses, and families are not able to come to a decision about medical treatment when value conflicts are involved. We present a report on the basis of medical ethics and personal experience and provide an overview on the impact of ethics consultations. Ethical conflicts are common in the surgical intensive care setting, since the patient's preferences often are not known exactly, and in modern "high-tech" intensive care medicine the prognosis of recovery and / or quality of life of (old) patients seems to be hard to assess. Ethical definitions of treatment perspectives will find an important and increasing place in intensive care competence in the future, although nowadays there is a lack of theoretical and practical instruction in ethics. The goal of ethics consultations is to help physicians, nurses and family members by structuring the problem and by a moderation of discussion and problem resolution including a special "ethical workflow". Ethics consultations seem to be useful in resolving conflicts that may inappropriately prolong unwanted treatments. The incidence of ethical conflicts increases even in surgical intensive care units and ethics consultations may help in the integration of ethics principles in clinical practice.

Treatment of complicated intra-abdominal infections in the era of multi-drug resistant Bacteria

The management of severe intra-abdominal infections remains a major challenge facing surgeons and intensive care physicians, because of its association with high morbidity and mortality. Surgical management and intensive care medicine have constantly improved, but in the recent years a rapidly continuing emergence of resistant pathogens led to treatment failure secondary to infections with multi-drug resistant bacteria. In secondary peritonitis the rate of resistant germs at the initial operation is already 30%. The lack of effective antibiotics against these pathogens resulted in the development of new broad-spectrum compounds and antibiotics directed against resistant germs. But so far no "super-drug" with efficacy against all resistant bacteria exists. Even more, soon after their approval, reports on resistance against these novel drugs have been reported, or the drugs were withdrawn from the market due to severe side effects. Since pharmaceutical companies reduced their investigations on antibiotic research, only few new antimicrobial derivates are available.In abdominal surgery you may be in fear that in the future more and more patients with tertiary peritonitis secondary to multi-drug resistant species are seen with an increase of mortality after secondary peritonitis.This article reviews the current treatment modalities for complicated intra-abdominal infections with special reference to the antibiotic treatment of complicated intra-abdominal infections with multi-drug resistant species.

Prebiotics, probiotics, synbiotics in surgery—are they only trendy, truly effective or even dangerous?

Despite advances in surgical technique and intensive care medicine, nosocomial bacterial infections frequently occur in patients after major abdominal surgery and have a negative impact on operative outcome and hospital costs. In parallel, the routine use of antibiotics led to the development of resistance. Some probiotics (living bacteria) and prebiotics (fibers) are able to stabilize the intestinal barrier and prevent bacterial translocation and infections. The aim of this article was to review all available experience with pro- and prebiotics in surgical trials. Medical databases were searched for animal trials and randomized controlled studies with pro- and prebiotics in surgical patients. Primary endpoint of all reported studies was the occurrence of bacterial infections. In addition, type and concentration of the pro- and prebiotics, duration of therapy, adverse events, and other effects were investigated. In three animal trials and in ten of the 15 clinical studies, probiotics or synbiotics led to a significant reduction of bacterial infection rates compared to the control groups. In two studies, there was a positive trend in the groups with synbiotics, but the results were not statistically significant. Two studies showed no effect, and in one study, the mortality rate was even higher in the synbiotic group. Except in the latter study, no severe adverse events were observed. The success of treatment depends on the synbiotic preparation and the length of therapy. Patients after surgery of the liver and pancreas and multiple trauma patients profited most from synbiotic treatment. The existing randomized controlled trials demonstrated a positive effect of synbiotics in patients with high-risk operations; however, synbiotic preparations should be extensively tested before using them in clinical trials.

Ventilation Management During Neonatal Thoracic Surgery

In Response: Drs. Bouchut and Claris (1) emphasize the beneficial effects of high-frequency oscillatory ventilation (HFOV) in cases of neonatal and pediatric acute lung injury. We fully agree that special infant ventilators and HFOV are an indispensable strategy in caring for preterm, newborn infants. However, although generally effective in maintaining and improving gas exchange in small infants, HFOV might not be the best approach in every setting. The major concern in infants with congenital emphysema is to protect the emphysematous regions from further over-expansion caused by positive airway pressure. In our patient, HFOV used during periods of recurrent pulmonary infection induced mediastinal shift with severe hemodynamic compromise. This required surgical removal of the left upper lobe (2). Because HFOV was responsible for this complication, we intervened by placing a pediatric endobronchial blocker in the left mainstem bronchus to establish single-lung ventilation, thus precluding further expansion of the emphysematous lobe. We would like to address some other concerns raised by Drs. Bouchut and Claris. First, the 4.0-mm ID endotracheal tube did not cause laryngotracheal trauma. In the neonatal intensive care unit, an air leak was observed with a 3.5-mm tube during periods of HFOV (2). Second, we did not adapt a technique for adults to our neonatal patients. The endobronchial blocking device used was designed and clinically validated for lung isolation in small infants. However, placement of the device generally requires an endotracheal tube with an inner diameter of at least 4.5 mm. The purpose of our report was to describe how we applied three distinct modifications of the recommended approach to permit use of an endobronchial blocker through a 4.0-mm endotracheal tube, permitting its use in newborns. Finally, we did not expose the neonate to lung injury by high peak airway pressures and sheer stress forces. During single-lung ventilation, we limited peak airway pressure to 25 cm H2O. While placing the endobronchial blocker, ventilation was continued through a “virtual” 3.0-mm endotracheal tube, obtained by subtracting the cross-sectional area of the blocker shaft (2.27 mm2) and the fiberoptic bronchoscope (3.14 mm2) from the cross-sectional area of a 4.0-mm endotracheal tube (12.57 mm2). The result, 7.16 mm2, is slightly larger than the area of a 3.0-mm endotracheal tube (7.07 mm2). After the fiberoptic bronchoscope was removed, the remaining cross section increased to 10.3 mm2, which exceeds the cross-sectional lumen of a 3.5-mm endotracheal tube (9.62 mm2). Despite a minute ventilation of 1.4–1.7 L at a respiratory rate between 30–40/min, carbon dioxide increased, reflecting the additional dead space added by the multiport adapter. Our surgeons consider conditions for open lung surgery satisfactory during intraoperative HFOV. However, confronted with the special challenges of our small patient, our surgeon determined that lung isolation was required before removing the over-expanded lobe. In summary, we have shown how to isolate a lung in small infants who require single-lung ventilation in the intensive care unit or operating room. Dietmar Enk, MD, PhD Department of Anesthesiology University Hospital Maastricht Maastricht, The Netherlands [email protected] Georg Rellensmann, MD Department of Pediatrics University of Münster Hospital Münster, Germany Thomas Brussel, MD, PhD, FANZCA Department of Anesthesiology and Pain Management The Canberra Hospital Australian National University Canberra, Australia Hugo Van Aken, MD, PhD, FRCA, FANZCA Department of Anesthesiology and Surgical Intensive Care Medicine Michael Semik, MD, PhD Department of Chest, Heart, and Vascular Surgery Christoph Schmidt, MD Department of Anesthesiology and Surgical Intensive Care Medicine University of Münster Hospital Münster, Germany

Surgical Intensive Care Medicine

Surgical Intensive Care Medicine

Einfluss der kardialen Zirkulation und einer herzwirksamen Medikation auf die Durchblutung der Bauchorgane

Perfusion of the abdomen is determined by cardiac function and circulation. Intestinal ischemia can be caused by Non occlusive bowel ischemia (NOD) that is important in internal as well as surgical intensive care medicine. Cardiac medication can influence perfusion of the bowel: 1) digitalis increases muscular tonus and decreases perfusion regulation b) diuretics lead to hypovolemia, hypotonia and malperfusion, c) antihypertensive medication can cause intraoperative hypotension that demands catecholamines, d) catecholamines can reduce perfusion by pathologic vasoconstriction in the splanchnicus area. Preoperative medication should respect 1) preoperatively taken ACE-inhibitors should be given postoperatively, as they have protective influence on the microcirculation of the bowel, 2) beta-blockers stabilize the myogenic tonus of the abdominal vessels, reduce an overshot of the parasympatheticus and diminish the risk of neurogenic abdominal shock, 3) catecholamines should be used with respect to ischemia of the bowel. Therapy of NOD should be focused on the primary vascular and hemodynamic causes and also take care for bacterial translocation and consecutive sepsis.

Surgical Intensive Care Medicine.

Department d'Anesthesie, Reanimation Chirurgicale Pierre Viars, Pitie-Salpetriere Hospital, University of Paris VI, Paris, France. jjrouby.pitie@invivo.eduSurgical Intensive Care Medicine. By John M. O'Donnell and Flávio E. Nácul. Burlington, Kluwer Academic Publishers, 2001. Pages: 900. Price $150.00.Drs. O'Donnell and Nacul have to be commended for their book entitled Surgical Intensive Care Medicine that summarizes, in 900 pages, the basic knowledge required to handle postoperative critically ill patients. In fact, the book is composed of two different parts: the first part contains basic principles of critical care medicine, such as airway management, vascular cannulation, evaluation of hemodynamics, sedation, infection, acid-base balance, gas exchange, etc. ; the second part concerns the specificities related to major surgical procedures, such as burns, orthopedic trauma, digestive, and cardiac or lung surgery. Great attention is paid to organ transplantation, with a whole chapter on “Care of the Organ Donor.” The authors took the option to imbricate these two parts rather than to separate general principles of intensive care medicine from specialized surgical intensive care. As a consequence, the book resembles a book on general intensive care medicine but constantly refers to surgical situations where specific postoperative problems calls for directed attitudes and therapies. This articulation keeps the attention of the reader and facilitates understanding.The chapters are written clearly and concisely. Illustrations, which could have been a little more developed, clarify and outline the most important points. The references are up-to-date and have been selected properly. Controversies on hot topics are identified clearly and treated in a balanced manner. In general, with a few exceptions like the chapter on venous thromboembolism, the numbers of abbreviations is reasonable and does not complicate the reading. Some chapters (such as “The Abdominal Compartment Syndrome,”“Care of the Organ Donor,” and “Disorders of Thermoregulation”) are original and add something new when compared to previous books published on critical care medicine. The book is easy to use, has an extensive index that is appropriate for rapidly finding a specific topic. At the end of the book, the authors also have provided a list of Web sites that should facilitate contacts and access to multiple sources of information regarding surgical critical care.The book Surgical Intensive Care Medicine will be an invaluable resource for residents and or anesthesiologists involved in surgical intensive care medicine, because it gives a synthetic and upgraded overview on a rapidly moving field. I strongly recommend this book, which should take its place in the break room of many intensive care units.

Chirurgie des komplizierten gastroduodenalen Ulkus: Eine Standortbestimmung zur Jahrtausendwende

Complications of gastroduodenal ulcers such as bleeding and perforation have been afflicted with a mortality of up to 40 % in the past. Altered ulcer manifestation by improvement of medical treatment as well as advances in surgical techniques and intensive care medicine might currently have improved the outcome of these severely ill patients. A retrospective analysis of 73 patients with emergency operation for bleeding or perforated gastric (n = 50) and duodenal ulcer (n = 23) between 10/1994 and 7/2001 was performed. The median age was 58 years (17-90 years) with 30 % of patients exceeding the age of 70 years. Eighty-one percent of patients had perforation, 19 % had bleeding. Factors predisposing for gastroduodenal ulcers were present in 88 %. Five percent of gastric perforations were due to gastric malignancies. Diagnosis of perforation was made in 88 % by conventional X-rays, in 12 % of perforations no free abdominal gas was detectable. A local surgical procedure (excision of ulcer and sutures/pyloroplasty) was performed in 64/73 patients (88 %), partial gastroduodenal resection was necessary in 9 patients (12 %). Histologic examination for helicobacter pylori was positive in 30/39 specimens (77 %). In-hospital mortality was 14 %, both for patients with bleeding and perforated ulcers. Surgical complications were 12 %. Altered ulcer manifestation, minimized surgical therapy and improved intensive care medicine led to a recent reduction in postoperative mortality of patients suffering from perforated or bleeding gastroduodenal ulcer. A further reduction of this still high mortality might be expected by improvement of surgical training and/or restriction of therapy to a limited number of surgeons.

Manipulation of the renin-angiotensin system.

Since the initial description of angiotensin II–mediated hypertension >40 years ago, basic and clinical investigations of the renin-angiotensin system (RAS) have resulted in a broader understanding of cardiovascular pathophysiology and significant advances in therapy. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor antagonists are now widely prescribed for the treatment of hypertension and left ventricular (LV) dysfunction; more recently, the aldosterone receptor antagonist, spironolactone, has proven beneficial in severe heart failure. This article will focus on our current understanding of the RAS and how pharmacological manipulation of this system can improve clinical outcomes in patients with cardiovascular disease. ### Pathophysiological Rationale for RAS Manipulation Renin is released by juxtuloglomerular cells in the kidney in response to renal hypoperfusion, decreased sodium delivery, and sympathetic activation (Figure 1). Angiotensinogen produced by the liver is cleaved by renin to yield the inactive decapeptide angiotensin I. Circulating angiotensin I is, in turn, converted to angiotensin II in the lungs by the action of ACE. ACE, or kininase II, also plays a key role in the kallikrein-kinin system by cleaving bradykinin to inactive peptides. In addition to the hormonal effects of circulating angiotensin II, all of the necessary components of the RAS exist in several organs and tissues, including the heart, kidneys, and vasculature. Figure 1. Pathophysiology of the RAS. SMC indicates smooth muscle cell. Angiotensin II exerts its actions in target organs and tissues by binding to both angiotensin II type 1 and 2 (AT1 and AT2) receptors, although adverse effects in humans seem to be mediated primarily by the AT1 receptor (Figure 1). In the kidney, angiotensin II causes sodium and water retention and efferent arteriolar vasoconstriction. Constriction of the systemic vasculature by angiotensin II causes hypertension, whereas coronary vasoconstriction may cause myocardial ischemia and arrhythmias. Angiotensin II–stimulated secretion of aldosterone by the adrenal cortex and arginine …