Noradrenaline and the kidney: friends or foes?

Septic shock, systemic inflammation and pharmacological vasodilatation are often complicated by systemic hypotension, despite aggressive fluid resuscitation and an increased cardiac output. If the physician wishes to restore arterial pressure (>80–85 mmHg), with the aim of sustaining organ perfusion pressure, the administration of systemic vasopressor agents, such as noradrenaline, becomes necessary. Because noradrenaline induces vasoconstriction in many vascular beds (visibly in the skin), however, it may decrease renal and visceral blood flow, impairing visceral organ function. This unproven fear has stopped clinicians from using noradrenaline more widely. In vasodilated states, unlike in normal circulatory conditions, however, noradrenaline may actually improve visceral organ blood flow. Animal studies show that the increased organ perfusion pressures achieved with noradrenaline improve the glomerular filtration rate and renal blood flow. There are no controlled human data to define the effects of noradrenaline on the kidney, but many patient series show a positive effect on glomerular filtration rate and urine output. There is no reason to fear the use of noradrenaline. If it is used to support a vasodilated circulation with a normal or increased cardiac output, it is likely to be the kidney's friend not its foe.     

Sepsis,Pneumonia, and Meningitis: What Is the Difference?

Sepsis, pneumonia, and meningitis are types of infections seen frequently in the neonate. The signs of sepsis can be an overwhelming, systematic response, or the signs can be localized to the place of infection, whether lungs, spinal fluid, or bones. It is important for nurses to understand how the source of infection and progression of the disease can cause changes in the signs of infection. Infection can invade the bloodstream, produce an inflammatory reaction, and cause shock with resulting multiple-organ dysfunction. A conceptual model of the progression of sepsis in the neonate will be presented. The importance of understanding the progression in the disease process will assist the nurse to facilitate prompt and effective treatment for the infant with sepsis.     

Sepsis therapy: what's the best for the mitochondria?

It is suspected that mitochondrial dysfunction is a major cause of organ failure in sepsis and septic shock. A study presented in this issue of Critical Care revealed that liver mitochondria from pigs treated with norepinephrine during endotoxaemia exhibit greater in vitro respiratory activity. The investigators provide an elegant demonstration of how therapeutic interventions in sepsis may profoundly influence mitochondrial respiration, but many aspects of mitochondrial function in sepsis remain to be clarified.     

Hip osteoarthritis and the active patient: will I run again?

The popularity of running as a recreational sport for health gains has steadily increased. Runners may acquire several types of injuries including hip osteoarthritis (OA). Running is possible with mild forms of OA if proper joint mechanics, neuromuscular control, and technique are present. Recent literature will be discussed that builds upon previously published articles regarding forces encountered at the hip joint during running. This article will outline the biomechanics and necessary muscle forces during running, and theories regarding strengthening and neuromuscular control. Perspectives on treatment, based on known evidence and our clinical reasoning are presented.     

Vasopressin in vasodilatory shock: hemodynamic stabilization at the cost of the liver and the kidney?

Infusing arginine vasopressin (AVP) in advanced vasodilatory shock is usually accompanied by a decrease in cardiac index and systemic oxygen transport. Whether or not such a vasoconstriction impedes regional blood flow and thus visceral organ function, even when low AVP is used, is still a matter of debate. Krejci and colleagues now report, in this issue of Critical Care, that infusing 'low-dose' AVP during early, short-term, normotensive and normodynamic fecal peritonitis-induced porcine septicemia markedly reduced both renal and portal blood flow, and consequently total hepatic blood flow, whereas hepatic arterial flow was not affected. This macrocirculatory response was concomitant with reduced kidney microcirculatory perfusion, whereas liver micro-circulation remained unchanged. From these findings the authors conclude that the use of AVP to treat hypotension should be cautioned against in patients with septic shock. Undoubtedly, given its powerful vasoconstrictor properties, which are not accompanied by positive inotropic qualities (in contrast with most of the equally potent standard care 'competitors', namely catecholamines), the safety of AVP is still a matter of concern. Nevertheless, the findings reported by Krejci and colleagues need to be discussed in the context of the model design, the timing and dosing of AVP as well as the complex interaction between visceral organ perfusion and function.     

The International Sepsis Forum's controversies in sepsis: how will sepsis be treated in 2051?

Great advances have been made in describing the intracellular pathways and genes that are activated by bacterial products. New definitions and therapies for sepsis will be based on such cellular and genetic alterations. In particular, in 2051 sepsis will no longer be defined simply as a clinical constellation of findings, but rather will be divided into different entities dependent on the intracellular cascades or genes activated. Similarly, therapies will be specifically directed at such functional genetic or biochemical alterations, thereby permitting more rational therapy of specific cellular abnormalities in infected patients. Supportive care will also have advanced by 2051, allowing for less iatrogenic harm to critically ill septic patients. Finally, a better appreciation of the cellular and genetic pathways that are activated in patients will permit an improved understanding of prognosis in critically ill infected patients, allowing more appropriate use of therapies.     

The International Sepsis Forum's controversies in sepsis: how will sepsis be treated in 2051?

Sepsis, the life-threatening illness that arises from innate immunity to overwhelming infection, is treated symptomatically at the start of the 21st century. Looking ahead 50 years, one can perhaps foresee profound changes in the way we manage this disorder. A shift from a focus on eradicating micro-organisms as universally inimical to one on supporting optimal host–microbial homeostasis will have a profound impact on how we treat infection, and will relegate antibiotics to a small, adjuvant role. Probiotic therapy may well be as important as antibiotic therapy. Resuscitation strategies will support microvascular flow rather than systemic pressure. Rapid genetic profiling will permit pre-emptive gene therapy for some, and titration of specific therapies directed against fundamental intracellular processes in others. We will treat diseases, not syndromes, and guide therapy by molecular staging. A fanciful victim of sepsis in 2051 illustrates how future treatments might transform sepsis from a prolonged and morbid illness to a rapidly reversed acute disease.     

Interprofessional collaboration in the ICU: how to define?*

The intensive care unit (ICU) is a dynamic, complex and, at times, highly stressful work environment that involves ongoing exposure to the complexities of interprofessional team functioning. Failures of communication, considered examples of poor collaboration among health care professionals, are the leading cause of inadvertent harm across all health care settings. Evidence suggests effective interprofessional collaboration results in improved outcomes for critically ill patients. One recent study demonstrated a link between low standardized mortality ratios and self-identified levels of collaboration. The aim of this paper is to discuss determinants and complexities of interprofessional collaboration, the evidence supporting its impact on outcomes in the ICU, and interventions designed to foster better interprofessional team functioning. Elements of effective interprofessional collaboration include shared goals and partnerships including explicit, complementary and interdependent roles; mutual respect; and power sharing. In the ICU setting, teams continually alter due to large staff numbers, shift work and staff rotations through the institution. Therefore, the ideal 'unified' team working together to provide better care and improve patient outcomes may be difficult to sustain. Power sharing is one of the most complex aspects of interprofessional collaboration. Ownership of specialized knowledge, technical skills, clinical territory, or even the patient, may produce interprofessional conflict when ownership is not acknowledged. Collaboration by definition implies interdependency as opposed to autonomy. Yet, much nursing literature focuses on achievement of autonomy in clinical decision-making, cited to improve job satisfaction, retention and patient outcomes. Autonomy of health care professionals may be an inappropriate goal when striving to foster interprofessional collaboration. Tools such as checklists, guidelines and protocols are advocated, by some, as ways for nurses to gain influence and autonomy in clinical decision-making. Protocols to guide ICU practices such as sedation and weaning reduce the duration of mechanical ventilation in some studies, while others have failed to demonstrate this advantage. Existing organizational strategies that facilitate effective collaboration between health care professionals may contribute to this lack of effect.