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In Section 6.1 we sum up with brief indications of the proofs some facts on the open sets in where a differential equation () = with constant coefficients can always be solved. Depending on whether is allowed to be an arbitrary distribution or a function (or a distribution of finite order), we get two classes of admissible open sets depending on . Those which are admissible for every are precisely the genuinely convex sets. However, more general domains are admissible for individual operators . In Section 6.2 we prove by methods close to those used in Section 4.2 that in a pseudo-convex open set in C all equations of the form can be solved. In fact, we prove more general results for operators in a product space × which have this structure with respect to the complex variables. In Section 6.3 we pass to the existence of analytic solutions of equations of the form (,..., ) = in a pseudo-convex open set ⊂ where is analytic. We show that it is precisely in the C convex sets that a solution exists for arbitrary and .

In summary, recent advances in understanding of the factors involved in experimental acute renal injury during endotoxemia suggest potential effective interventions. Prospective, randomized studies in septic patients at risk of acute renal failure are, therefore, needed to examine potential therapies to decrease the morbidity and mortality associated with this frequent and devastating clinical problem.

The esophageal Doppler technique has progressively emerged as a minimally invasive and reliable tool for measuring aortic blood flow and estimating cardiac output. Numerous studies have emphasized its clinical utility by showing improved outcome in surgical patients when hemodynamic therapy was driven by algorithms based on esophageal Doppler data. In the setting of the ICU, the ability of esophageal Doppler to track the changes in aortic blood flow in a beat-to-beat manner makes it particularly suitable for predicting fluid responsiveness, either by the measurement of the aortic blood flow respiratory variation or by testing the effects of passive leg raising.

ANP and BNP are secreted from cardiac myocytes in response to atrial or ventricular wall stretch. The physiologic effects of both cardiac natriuretic peptides include natriuresis, diuresis, and inhibition of the activities of several neuroendocrine systems, including the renin-angiotensin-aldosterone system, endothelins, cytokines, and the sympathetic nervous system. Single and serial plasma measurement of BNP is a promising tool for diagnosis and risk stratification of patients with heart failure and acute coronary syndromes. Levels of BNP could also be used to guide drug therapy in these patients. Finally, the administration of nesiritide, a synthetic recombinant human BNP, appears to offer a novel approach in the management of acute heart failure.

The PFAD system has proved to be an efficient treatment in endotoxic shock in an animal model. This new method of plasma purification utilizes the capacity of the plasma as a means of transport for toxins and can hence be used to bring them to the filters, clearing the organism. Also based on our preliminary results, it appears that extracorporeal treatment using the PFAD system is one of the most promising therapies in treating the dysfunctions related to circulating mediators, such as cytokines, bilirubin, biliary acids and endotoxemia, all of which are the basis of other more complex pathologies (sepsis, systemic inflammatory response syndrome [SIRS], hepatorenal syndrome, chronic and acute liver failure, brain death donors).

Considering the positive results obtained so far, it would be enlightening to study how subjects with other similar medical conditions respond to this system, thus verifying the effectiveness of the PFAD system in other critical diseases.

Sleep in the ICU is an avenue of scientific research which is only now starting to evolve. There are at least three factors that make the ICU scenario unique. The first of these is the particular environment, characterized by a background of noises, changes in lighting and constant patient-care activities. Surprisingly, the environment has been shown to play but a small role in sleep disruption. The second factor is the acuity of illness; some studies suggest a relationship between normalization of sleep architecture and recovery from an illness. And the third factor is the widespread use of sedation associated with mechanical ventilation. The ventilatory modality and its settings have an impact on sleep quality, suggesting there is a relative hyperventilation during sleep, adding to sleep fragmentation. Regarding sedatives, we know that these drugs disrupt physiological sleep. All these factors, either alone or interacting together, have some impact on ICU patients’ sleep architecture. A deeper understanding of sleep physiopathology and the use of a more physiological approach to setting the ventilator could help to improve sleep quality.

A review of the literature raises the question of how important it is to monitor the quality of sleep in the ICU to avoid clinical consequences such as delirium that seem to be independently associated with worse outcomes, such as prolonged ventilator dependence, ICU length of stay, and hospital length of stay, and is an independent predictor of higher 6-month mortality. Every day spent by ICU patients in a state of delirium is associated with a 10% higher risk of death and worse long-term cognitive function, and delirium is associated with an increase in costs. Taking into consideration the increasing number of elderly patients treated in our ICUs, this burden will rise. Future research should focus on the pathophysiology, cause, and treatment of sleep deprivation and of the occurrence of delirium.

Further research is needed to understand the processes behind the formation of delusional memories on the ICU and to examine the impact of therapeutic interventions undertaken within the ICU such as altering sedation practice on later psychological health.

The growth of counselling services for patients diagnosed with cancer is in recognition of the psychological impact of severe illness. At present only about a third of ICUs in the UK follow up their patients in a dedicated clinic. The provision of counselling or psychology services specifically for this patient group is sparse. Psychological services for post-ICU patients are required so that each patient is appropriately assessed and given the necessary support. Physical recovery after critical illness is on the whole good, although it is a lengthy process. If psychological services are not available for some patients, their optimal quality of life may never be achieved.

CPAP is a simple and effective ventilatory treatment for acute respiratory failure related to specific conditions. CPAP (10 cm HO) should be considered as the first-line ventilator treatment for achieving prompt physiologic improvement and lower rates of endotracheal intubation in severe cardiogenic pulmonary edema. CPAP is effective for managing postoperative hypoxemia, enabling improved outcomes in selected patients, provided it is applied for a sufficient period of time. CPAP is also useful during fiberoptic bronchoscopy in hypoxemic patients to prevent subsequent acute respiratory failure. Although application of non-invasive CPAP cannot be generally recommended in the early stage of hypoxemic acute respiratory failure related to ALI/ARDS or pneumonia, CPAP may be beneficial in high-risk, immunocompromised patients. Surprisingly, no study has yet evaluated the effectiveness of early use of CPAP alone in improving outcome in patients with acute exacerbation of COPD. In contrast, use of PEEP/CPAP is often detrimental and is not advisable in other conditions, such as in patients undergoing mechanical ventilation for acute severe asthma.

The multidisciplinary approach of the project is improving patient safety by continuous quality assessment and modification guided by monthly, real data. Cost effectiveness of patient safety management systems is an important issue, especially in relation to the increasing costs of health care, which should be considered as an integral part of such a system.