Spontaneous remission of acute myeloid leukaemia after recovery from sepsis

Spontaneous remission of acute myeloid leukaemia (AML) is extremely rare and usually of short duration. We report two patients with documented AML who developed spontaneous remission of their leukaemia shortly after an episode of severe sepsis and respiratory failure requiring mechanical ventilation. The underlying mechanisms of spontaneous remission remain unclear but an association with preceding blood transfusions and severe systemic infections has been reported. An overwhelming immune response due to sepsis and leading to raised levels of TNF-alpha, INF-gamma, IL -2 and an increased activity of NK cells, cytotoxic T-cells and macrophages are thought to play an important role. Better insights into the mechanisms of spontaneous remission of AML after recovery from sepsis could help in developing new therapies for AML.

Relative adrenal insufficiency: an identifiable entity in nonseptic critically ill patients?

OBJECTIVE

To determine whether relative adrenal insufficiency (RAI) can be identified in nonseptic hypotensive patients in the intensive care unit (ICU).

DESIGN

Retrospective study in a medical-surgical ICU of a university hospital.

PATIENTS

One hundred and seventy-two nonseptic ICU patients (51% after trauma or surgery), who underwent a short 250 microg ACTH test because of > 6 h hypotension or vasopressor/inotropic therapy.

MEASUREMENTS

On the test day, the Simplified Acute Physiology Score II (SAPS II) and Sequential Organ Failure Assessment (SOFA) score were calculated to estimate disease severity. The ICU mortality until day 28 was recorded. Best discriminative levels of baseline cortisol, increases and peaks were established using receiver operating characteristic curves. These and corticosteroid treatment (in n = 112, 65%), among other variables, were examined by multiple logistic regression and Cox proportional hazard regression analyses to find independent predictors of ICU mortality until day 28.

RESULTS

ICU mortality until day 28 was 23%. Nonsurvivors had higher SAPS II and SOFA scores. Baseline cortisol levels correlated directly with albumin levels and SAPS II. In the multivariate analyses, a cortisol baseline > 475 nmol/l and cortisol increase < 200 nmol/l predicted mortality, largely dependent on disease severity but independent of albumin levels. Corticosteroid (hydrocortisone) treatment was not associated with an improved outcome, regardless of the ACTH test results.

CONCLUSION

In nonseptic hypotensive ICU patients, a low cortisol/ACTH response and treatment with corticosteroids do not contribute to mortality prediction by severity of disease. The data thus argue against RAI identifiable by cortisol/ACTH testing and necessitating corticosteroid substitution treatment in these patients.

Herpes simplex virus type 1 and respiratory disease in critically-ill patients: real pathogen or innocent bystander?

Herpes simplex virus type 1 (HSV-1) has been associated with pulmonary disease, mostly in severely immunocompromised patients. After reactivation and shedding in the oropharynx, the virus may reach the lower respiratory tract by aspiration or by contiguous spread. HSV-1 can be detected in clinical specimens by virus culture or quantitatively by nucleic acid amplification techniques. With these techniques, HSV-1 is often detected in the respiratory secretions of critically-ill patients. However, a clear diagnosis of HSV-1 pneumonia is difficult to establish because clinical criteria, radiological features and laboratory findings all lack specificity. Lower respiratory tract HSV-1 infections have not been associated with specific risk-factors. There is also an absence of consistent data concerning the effect of antiviral treatment on the outcome of critically-ill patients. Further studies are needed to better define the pathogenic role of HSV-1 in the lower respiratory tract of these patients, to improve the diagnosis, and, especially, to assess the need for antiviral treatment in the individual patient.

Attitudes of European physicians, nurses, patients, and families regarding end-of-life decisions: the ETHICATT study

OBJECTIVE

To evaluate attitudes of Europeans regarding end-of-life decisions.

DESIGN AND SETTING

Responses to a questionnaire by physicians and nurses working in ICUs, patients who survived ICU, and families of ICU patients in six European countries were compared for attitudes regarding quality and value of life, ICU treatments, active euthanasia, and place of treatment.

MEASUREMENTS AND RESULTS

Questionnaires were distributed to 4,389 individuals and completed by 1,899 (43%). Physicians (88%) and nurses (87%) found quality of life more important and value of life less important in their decisions for themselves than patients (51%) and families (63%). If diagnosed with a terminal illness, health professionals wanted fewer ICU admissions, uses of CPR, and ventilators (21%, 8%, 10%, respectively) than patients and families (58%, 49%, 44%, respectively). More physicians (79%) and nurses (61%) than patients (58%) and families (48%) preferred being home or in a hospice if they had a terminal illness with only a short time to live.

CONCLUSIONS

Quality of life was more important for physicians and nurses than patients and families. More medical professionals want fewer ICU treatments and prefer being home or in a hospice for a terminal illness than patients and families.

Cardiac response is greater for colloid than saline fluid loading after cardiac or vascular surgery

OBJECTIVE

To study the effects on volume expansion and myocardial function of colloids or crystalloids in the treatment of hypovolaemic hypotension after cardiac and major vascular surgery.

DESIGN AND SETTING

A single-centre, single-blinded, randomized clinical trial at the intensive care unit of a university hospital.

PATIENTS AND METHODS

Patients (n=67) were subjected to a 90-min filling pressure-guided fluid challenge with saline 0.9% or the colloids gelatin 4%, hydroxyethyl starch 6% or albumin 5%. Biochemical variables and haemodynamics (transpulmonary thermodilution) were measured.

RESULTS

An amount of 1800 (1300-1800) ml of saline or 1600 (750-1800) ml of colloid solution (P< 0.005) was infused. Colloid osmotic pressure (COP) decreased in the saline group and increased in the colloid groups (P< 0.001). Plasma volume increased by 3.0% (-18 to 24) in the saline versus 19% (-11 to 50) in the colloid groups (P< 0.001). Cardiac index increased by median 13% (ns) in the saline group and by 22% in the colloid groups (P<0.005). The rise in left ventricular stroke work index was greater in the colloid than in the saline groups. The different colloids were equally effective. The rise in cardiac index related to the rise in plasma volume and global end-diastolic volume, confirming plasma volume and preload augmentation by the fluid loading.

CONCLUSION

After cardiac or major vascular surgery, the pressure- and time-guided fluid response is dependent on the type of fluid used. Colloid fluid loading leads to a greater increase in preload-recruitable cardiac and left ventricular stroke work indices than that with saline, because of greater plasma volume expansion following an increase in plasma COP.

Circulating cardiovascular markers and mediators in acute illness: an update

An update is given of the circulating markers and mediators of cardiovascular dysfunction in acute illness. Some of these circulating markers reflect mediator action on the peripheral vasculature, such as endothelium-derived endothelin and nitrite/nitritate, the stable end products of nitric oxide. Other markers mainly reflect actions on the heart, such as the natriuretic peptide family, released from the heart upon dilatation, serving as a marker of congestive heart failure and potentially having negative inotropic effects. Indeed, some factors may be both markers as well as mediators of cardiovascular dysfunction of the acutely ill and bear prognostic significance. Assessing circulating levels may help refine clinical judgment of the cardiovascular derangements encountered at the bedside, together with clinical signs and hemodynamic variables. For instance, assessing natriuretic peptides in patients with pulmonary edema of unclear origin may help to diagnose congestive heart failure and cardiogenic pulmonary edema, when the pulmonary capillary wedge pressure is not measured or inconclusive. Future aligning of hemodynamic abnormalities with patterns of circulating cardiovascular markers/mediators may help to stratify patients for inclusion in studies to assess the causes, response to therapy and prognosis of cardiovascular derangements in the acutely ill.

The immunoneuroendocrine axis in critical illness: beneficial adaptation or neuroendocrine exhaustion?

PURPOSE OF REVIEW

Over the last years, endocrinology has been incorporated in critical care medicine, and acknowledgment of the complex neuro-endocrine adaption of critical illness has led to new insights and major breakthroughs in clarifying pathophysiological mechanisms and the targeting of therapeutic strategies. This review focuses on the important role of the hypothalamic-pituitary-adrenal (HPA) axis during critical illness and the occurrence of neuroendocrine failure.

RECENT FINDINGS

The distinction between acute (activated anterior pituitary function and inactivated peripheral anabolic pathways) and prolonged (reduced neuroendocrine stimulation) critical illness as different neuroendocrine paradigms has brought a new approach to the critically ill patient. The HPA adaptation in the prolonged phase is characterized by hypercortisolism induced by non-ACTH driven pathways as ACTH levels are low. In spite of the high-normal (total) cortisol levels, HPA insufficiency appears to be quite common. On the other hand, there is a marked depletion of corticosteroid-binding globulin (CBG) in the acute phase of critical illness, resulting in increased free and biologically active cortisol. There is a persistent marked depletion of dehydroeplandrosterone sulfate, possibly indicating adrenal exhaustion, while macrophage inhibitory factor is upregulated in sepsis, affecting and contraregulating the biological effects of glucocorticoids.

SUMMARY

The endocrine system is highly interrelated with the immune and neural systems, the neuroimmunoendocrine axis is subject to clear biphasic changes in the acute and chronic phases of critical illness, most likely reflecting a beneficial adaptation. These neuroendocrine dynamics should be considered when assessing the neuroendocrine system, in particular the HPA axis.

Respiratory herpes simplex virus type 1 infection/colonisation in the critically ill: marker or mediator?

BACKGROUND

The clinical significance and pulmonary pathogenicity of herpes simplex virus type 1 (HSV-1) in mechanically ventilated, critically ill patients are unclear.

OBJECTIVE

To determine the clinical features and course of respiratory HSV-1 infections/colonisations in the critically ill, in order to evaluate the contribution to outcome.

DESIGN

A retrospective cohort study in the intensive care unit of an university hospital, involving 22 patients with a HSV-1 isolated from bronchoalveolar lavage (BAL) fluid, divided into survivors (n = 13) and non-survivors (n = 9). All patients except for one survivor had been intubated and were mechanically ventilated.

RESULTS

Non-survivors had acquired HSV-1 sooner on mechanical ventilation than survivors. Prior chronic heart disease was more prevalent in non-survivors than in survivors and, at the time of HSV-1 isolation, the mean creatinine level was higher (P < 0.05) in the former. Survivors had a somewhat greater fall in body temperature after a 10-day course of antiviral therapy than non-survivors, but the lung radiographic abnormalities prior to and after the course did not differ. There were no major differences in cardiorespiratory variables between outcome groups and causes of death and were judged not to relate, in general, to HSV-1.

CONCLUSIONS

Critically ill patients in whom HSV-1 from BAL is isolated, have about 40% chance of dying, mainly because of severe underlying disease and comorbidity, which may predispose to endogenous reactivation of the virus. There is no clinical evidence for direct cardiorespiratory pathogenicity and beneficial effects of antiviral therapy. HSV-1 isolated from lung secretions may thus be a marker rather than a mediator of severe illness.

Herpes simplex virus type 1 and normal protein permeability in the lungs of critically ill patients: a case for low pathogenicity?

Introduction

The pathogenicity of late respiratory infections with herpes simplex virus type 1 (HSV-1) in the critically ill is unclear.

Methods

In four critically ill patients with persistent pulmonary infiltrates of unknown origin and isolation of HSV-1 from tracheal aspirate or bronchoalveolar lavage fluid, at 7 (1–11) days after start of mechanical ventilatory support, a pulmonary leak index (PLI) for ⁶⁷Gallium (⁶⁷Ga)-transferrin (upper limit of normal 14.1 × 10^-3/min) was measured.

Results

The PLI ranged between 7.5 and 14.0 × 10^-3/min in the study patients. Two patients received a course of acyclovir and all survived.

Conclusions

The normal capillary permeability observed in the lungs argues against pathogenicity of HSV-1 in the critically ill, and favors that isolation of the virus reflects reactivation in the course of serious illness and immunodepresssion, rather than primary or superimposed infection in the lungs.

Endotoxin and the hypothalamo-pituitary-adrenal (HPA) axis

Endotoxin is considered to be a systemic (immunological) stressor eliciting a prolonged activation of the hypothalamo-pituitary-adrenal (HPA) axis. The HPA-axis response after an endotoxin challenge is mainly due to released cytokines (IL-1, IL-6 and TNF-alpha) from stimulated peripheral immune cells, which in turn stimulate different levels of the HPA axis. Controversy exists regarding the main locus of action of endotoxin on glucocorticoid secretion, since the effect of endotoxin on this neuro-endocrine axis has been observed in intact animals and after ablation of the hypothalamus; however, a lack of LPS effect has been described at both pituitary and adrenocortical levels. The resulting increase in adrenal glucocorticoids has well-documented inhibitory effects on the inflammatory process and on inflammatory cytokine release. Therefore, immune activation of the adrenal gland by endotoxin is thought to occur by cytokine stimulation of corticosteroid-releasing hormone (CRH) production in the median eminence of the hypothalamus, which, in turn stimulates the secretion of ACTH from the pituitary. Acute administration of endotoxin stimulates ACTH and cortisol secretion and the release of CRH and vasopressin (AVP) in the hypophysial portal blood. During repeated endotoxemia, tolerance of both immune and HPA function develops, with a crucial role for glucocorticoids in the modulation of the HPA axis. A single exposure to a high dose of LPS can induce a long-lasting state of tolerance to a second exposure of LPS, affecting the response of plasma TNF-alpha and HPA hormones. Although there are gender differences in the HPA response to endotoxin and IL-1, these responses are enhanced by castration and attenuated by androgen and estrogen replacement. Estrogens attenuate the endotoxin-induced stimulation of IL-6, TNF-alpha and IL-1ra release and subsequent activation in postmenopausal women. There appears to be a temporal and functional relation between the HPA-axis response to endotoxin and nitric oxide formation in the neuro-endocrine hypothalamus, suggesting a stimulatory role for nitric oxide in modulating the HPA response to immune challenges.

Macrophage migration inhibitory factor as a counter-regulatory mediator of cortisol during septic shock

Background

Migration inhibitory factor (MIF) is a widely expressed protein that is secreted in response to inflammatory or hormonal stimuli. MIF is both an endocrine hormone and immunological mediator that counter-regulates glucocorticoid (GC) action. The anti-inflammatory and immunosuppressive properties of GC are often beneficial but host homeostasis requires counter-regulatory systems for which MIF has been proposed.

Methods

Using a time-resolved fluorometric immunoasssay to detect serum MIF levels in patients with septic shock or multitrauma, the relation of MIF to cortisol and adrenocorticotrophic hormone (ACTH) was studied. Serum MIF, cortisol and ACTH were measured serially over 14 days in patients with septic shock (n = 28) and multitrauma (n = 5), and in healthy controls (n = 41). Haemodynamics, Acute Physiology and Chronic Health Evaluation II scores and intensive care unit deaths were also recorded.

Results

MIF levels were raised significantly on day 1 in septic shock (mean(s.d.) 12·5(3·7) ng ml−1) compared with trauma (3·1(1·7) ng ml−1) and controls (2·5(2·1) ng ml−1). The time course of both MIF and cortisol showed persistently high levels in sepsis, independent of shock reversal or haemodynamics. Non-survivors had higher MIF levels than survivors from septic shock (P &lt; 0·05). Regression analysis showed a significant correlation between MIF and cortisol levels (r = 0·72), but no correlation was found between MIF and other variables.

Conclusion

Increased serum MIF levels occurred in septic shock compared with trauma and controls. In septic shock a clear correlation was found between MIF and cortisol levels, suggesting a parallel increase of MIF with cortisol and indicating a counter-regulatory activity of MIF to dampen the protective effects of GC. Non-survivors had higher MIF levels at most time points, indicating that MIF might be a potential prognostic marker in septic shock.

Insulin: a wonder drug in the critically ill?

Stress hyperglycaemia is a common event in acute critical illness. There is increasing evidence that maintaining normoglycaemia and treatment with insulin (or with glucose-insulin-potassium [GIK]), even in non-diabetic persons, is helpful in limiting organ damage after myocardial infarction, stroke, traumatic brain injury and other conditions, even though the conditions may be accompanied by insulin resistance. A landmark study now suggests that maintaining normoglycaemia with intensive insulin treatment in a heterogeneous population of critically ill patients decreases morbidity and mortality. The potential mechanisms that underlie such a beneficial effect are discussed.

Decreased levels of dehydroepiandrosterone sulphate in severe critical illness: a sign of exhausted adrenal reserve?

INTRODUCTION

Dehydroepiandrosterone (DHEA) and its sulphate (DHEAS) are pleiotropic adrenal hormones with immunostimulating and antiglucocorticoid effects. The present study was conducted to evaluate the time course of DHEAS levels in critically ill patients and to study their association with the hypothalamic-pituitary-adrenal axis.

MATERIALS AND METHOD

This was a prospective observational clinical and laboratory study, including 30 patients with septic shock, eight patients with multiple trauma, and 40 age- and sex-matched control patients. We took serial measurements of blood concentrations of DHEAS, cortisol, tumour necrosis factor-alpha and IL-6, and of adrenocorticotrophic hormone immunoreactivity over 14 days or until discharge/death.

RESULTS

On admission, DHEAS was extremely low in septic shock (1.2 +/- 0.8 mol/l) in comparison with multiple trauma patients (2.4 +/- 0.5 micromol/l; P < 0.05) and control patients (4.2 +/- 1.8; P < 0.01). DHEAS had a significant (P < 0.01) negative correlation with age, IL-6 and Acute Physiology and Chronic Health Evaluation II scores in both patient groups. Only during the acute phase did DHEAS negatively correlate with dopamine. Nonsurvivors of septic shock (n = 11) had lower DHEAS levels (0.4 +/- 0.3 micromol/l) than did survivors (1.7 +/- 1.1 micromol/l; P < 0.01). The time course of DHEAS exhibited a persistent depletion during follow up, whereas cortisol levels were increased at all time points.

CONCLUSION

We identified extremely low DHEAS levels in septic shock and, to a lesser degree, in multiple trauma patients as compared with those of age- and sex-matched control patients. There appeared to be a dissociation between DHEAS (decreased) and cortisol (increased) levels, which changed only slightly over time. Nonsurvivors of sepsis and patients with relative adrenal insufficiency had the lowest DHEAS values, suggesting that DHEAS might be a prognostic marker and a sign of exhausted adrenal reserve in critical illness.

The hypothalamic-pituitary-adrenal response to critical illness

The maintenance of life depends on the capacity of the organism to sustain its equilibrium via allostasis'-the ability to achieve stability through change. Life-threatening disease induces acute adaptive responses specific to the stimulus and generalized responses when the disturbances are prolonged. These changes are associated with increased activity of the hypothalamic-pituitary-adrenal axis and may have survival value in preparing the body for fight or flight'. There is a shift towards an increase in glucocorticoid production and away from mineralocorticoid and androgen production, as well as an increase in the biological effects of glucocorticoids through an increased cortisol free fraction and an increased glucocorticoid receptor sensitivity. During the prolonged phase, there is a dissociation between high plasma cortisol and low adrenocorticotropin hormone levels, suggesting non-adrenocorticotropin hormone-mediated mechanisms for the regulation of the adrenal cortex. This hypercortisolism is in contrast to the very low dehydroepiandrosterone sulphate level, indicating an imbalance between the immunostimulatory and immunosuppressive adrenocortical hormones. The question is whether the total serum cortisol concentration represents sufficient glucocorticoid biological activity during the prolonged phase of critical illness.