Director General ICU Raymond Poincaré Hospital University of Versailles France.
Claude Bernard has introduced the concept of intensive care when arguing in favour of restoring homeostasis as a key point of diseases management. Intensive care became more concrete to people in the middle of the 20th century when the introduction of lung iron to support respiratory function prevented death in most of victims of the poliomyelitis pandemic. Politics rapidly got the importance of creating specific places to deliver life-supporting treatments for acutely ill patients. Thereafter, Intensive Care Units (ICUs) were built all around the world including industrialised and emerging countries and became the hot corner of hospitals. Amazingly, there is no consensus on what should be an optimal ICU. They are markedly different across countries in design and resources and in management and care delivery. Thus, unsurprisingly, death rates in the ICUs vary on an average from 8 to 20 per cent around the world. Analysing the causes of death in ICUs is risky. Basically, people may die as a direct consequence of the critical illness, as a consequence of underlying co-morbidities, secondary to iatrogenic events, or as a consequence of withholding, withdrawing life-supportive treatments. Intuitively, there is little to do on co-morbid conditions or decision to terminate care. Thus, reducing ICU mortality should focus on advances in the management of critical illness and the prevention of iatrogenic complications.
Sepsis accounts for a greater number of diseases related deaths in the ICU.
Severe sepsis and septic shock are even today associated with 20-25 per cent and 40-45 per cent of mortality rates, respectively. Halting sepsis related deaths should be a priority for physicians, researchers, health policy makers and pharmaceutical industries. This is a reasonable goal to achieve. Undoubtedly, some progress has already been done and implementing the Surviving Sepsis Campaign bundles results in substantial survival benefit.
Most of the recommendations are simple measures (the first 6-hour bundles), e.g. early antibiotic treatment and source control and restoring cardiovascular homeostasis, that can be applied right away almost everywhere and may have a substantial impact on survival. Similarly, when sepsis is associated with acute lung injury or acute respiratory distress syndrome, keeping plateau pressures in the airway low, e.g. 25 cmH20 or less may prevent death in many patients. More complex strategies need to be used as second line measures in patients who failed to respond to the first 6-hour bundles. They may include maintaining blood glucose levels below 150 mg / dl, infusing activated protein C for four days, and low dose of corticosteroids, i.e. 200 mg of hydrocortisone or equivalent, for a week. These second line strategies are aimed at restoring metabolic, haemostatic and immune homeostasis. So, applying the original concept developed by Claude Bernard of maintaining homeostasis seems a very successful approach to deadly critical illness like sepsis.
In the very near future, one expects that most, if not all, patients with severe sepsis or septic shock will be treated according to the Surviving Sepsis Campaign. In addition, prioritising a better understanding of the mechanisms behind the chaotic nature of critical illness and designing diagnostic tools to recognise subtle loss in biological systems, homeostasis are key determinants for the development of successful treatments for sepsis and non-septic systemic inflammatory response syndromes.
Right now, the prevention of iatrogenic complications in the ICU is a top priority to reduce deaths. The critically ill patient is exposed to a number of drugs. Yet, for most of the medications, the pharmacokinetics during critical illness remain unclear, and little is known about interactions between drugs. For example, activated protein C and corticosteroids may be widely used in combination to treat septic shock, though safety data are lacking. The pharmaceutical companies should be included in the development of novel drugs particularities related to critical illness. The incidence of ICU acquired superinfections is still unacceptably high, albeit the efficacy of several preventive measures is already recognised. The attributable mortality of blood stream infection or ventilator associated pneumonia may reach 20 per cent.
There is an urgent need for tools allowing a more efficient translation of evidence based information to the bedside. It is also paramount to develop new strategies for the prevention of multi-resistant microorganisms. Life-support therapies that are so paramount to surviving critical illness, e.g. mechanical ventilation, renal replacement therapy or vasopressor therapy, are also associated with life-threatening complications. These treatments need to be adjusted a la carte in individual patients on a continuous basis, which is almost unfeasible by humans. Thus, researchers are developing close-loop systems providing computer guided adjustments of life-supportive therapies. In the near future, new automated systems will ease ICU patient monitoring and secure delivery of sophisticated treatments. So, it is expected that the cost related to ICU will continue to increase and this may be accepted by people only if ICU risk of death is minimised.
Djillali Annane is a Professor in Medicine at university of Versailles and the Director of the general ICU at Raymond Poincaré Hospital (Assistance Publique Hopitaux de Paris). His main research area is pathomechanisms and treatment of sepsis. He has written more than hundred and fifty papers in medical journals and textbook, including NEJM, JAMA, Lancet.