Antoine Baumann

Endocrine response after severe subarachnoid hemorrhage related to sodium and blood volume regulation.

BACKGROUND: Hyponatremia is often associated with, and worsens, the prognosis of severe aneurysmal subarachnoid hemorrhage (SAH). Several possible endocrine perturbations of variable severity and variable sodium and water intake have been described in SAH. However, a comprehensive study of the different hormonal systems involved in sodium and water homeostasis and circulating blood volume modifications is still needed. Our aim was to assess water and sodium regulation after severe SAH by investigating blood volume and several hormonal regulatory systems in the context of hyponatremia prevention by controlled sodium intake. METHODS: Nineteen mechanically ventilated patients with severe SAH, were prospectively studied. Replacement of sodium was at least 4.5 mmol · kg−1 · d−1 and adjusted on natriuresis. Hormones involved in electrolyte and water homeostasis: vasopressin, renin, angiotensin, aldosterone, and natriuretic peptides were assessed every 3 days for 12 days. Red blood cell volume was measured by the isotopic method (technetium–labeled red blood cells), in the first 48 h after admission and at day 7. Cardiac function was assessed using electrocardiogram, transthoracic echocardiography, and troponin Ic (cTnI). Outcome was assessed at 3 mo. RESULTS: After SAH onset, hyponatremia, but not decreased circulating blood volume, was prevented by high sodium and water infusion adapted to renal excretion. The hormonal profiles were characterized by an increase in renin, angiotensin II, natriuretic peptide concentrations associated with increased troponin Ic, stable low levels of vasopressin, and the absence of increased aldosterone concentrations. There were no correlations between hormone concentrations and natriuresis. CONCLUSION: After severe SAH, in the context of multiple clinical interventions, increased natriuresis and low blood volume are consistent with cerebral salt wasting syndrome, probably related to the sequence of severe SAH, highly increased sympathetic tone, hyperreninemic hypoaldosteronism syndrome, and increased natriuretic peptides release.

Elective non-therapeutic intensive care and the four principles of medical ethics

The chronic worldwide lack of organs for transplantation and the continuing improvement of strategies for in situ organ preservation have led to renewed interest in elective non-therapeutic ventilation of potential organ donors. Two types of situation may be eligible for elective intensive care: patients definitely evolving towards brain death and patients suitable as controlled non-heart beating organ donors after life-supporting therapies have been assessed as futile and withdrawn. Assessment of the ethical acceptability and the risks of these strategies is essential. We here offer such an ethical assessment using the four principles of medical ethics of Beauchamp and Childress applying them in their broadest sense so as to include patients and their families, their caregivers, other potential recipients of intensive care, and indeed society as a whole. The main ethical problems emerging are the definition of beneficence for the potential organ donor, the dilemma between the duty to respect a dying patients autonomy and the duty not to harm him/her, and the possible psychological and social harm for families, caregivers other potential recipients of therapeutic intensive care, and society more generally. Caution is expressed about the ethical acceptability of elective non-therapeutic ventilation, along with some proposals for precautionary measures to be taken if it is to be implemented.

Refractory Anaphylactic Cardiac Arrest After Succinylcholine Administration

Refractory shock from anaphylaxis can occur after induction of general anesthesia. We report two cases of fatal cardiac arrest with increased blood tryptase and immunoglobulin E values after succinylcholine administration. Tryptase and immunoglobulin E assays may help to identify anaphylactic reactions when cardiac arrest occurs at induction of anesthesia.

Non-therapeutic intensive care for organ donation A healthcare professionals’ opinion survey

Background and Purpose: Providing non-therapeutic intensive care for some patients in hopeless condition after cerebrovascular stroke in order to protect their organs for possible post-mortem organ donation after brain death is an effective but ethically tricky strategy to increase organ grafting. Finding out the feelings and opinion of the involved healthcare professionals and assessing the training needs before implementing such a strategy is critical to avoid backlash even in a presumed consent system. Participants and methods: A single-centre opinion survey of healthcare professionals was conducted in 2013 in the potentially involved wards of a French University Hospital: the Neurosurgical, Surgical and Medical Intensive Care Units, the Stroke Unit and the Emergency Department. A questionnaire with multiple-choice questions and one open-ended question was made available in the different wards between February and May 2013. Ethical considerations: The project was approved by the board of the Lorraine University Diploma in Medical Ethics. Results: Of a total of 340 healthcare professionals, 51% filled the form. Only 21.8% received a specific education on brain death, and only 18% on potential donor’s family approach and support. Most healthcare professionals (93%) think that non-therapeutic intensive care is the continuity of patient’s care. But more than 75% of respondents think that the advance patient’s consent and the consent of the family must be obtained despite the presumed consent rule regarding post-mortem organ donation in France. Conclusion: The acceptance by healthcare professionals of non-therapeutic intensive care for brain death organ donation seems fairly good, despite a suboptimal education regarding brain death, non-therapeutic intensive care and families’ support. But they ask to require previously expressed patient’s consent and family’s approval. So, it seems that non-therapeutic intensive care should only remain an ethically sound mean of empowerment of organ donors and their families to make post-mortem donation happen as a full respect of individual autonomy.

Désordres hydroélectrolytiques des agressions cérébrales : mécanismes et traitements

Electrolyte disturbances are frequent after brain injuries, especially dysnatremia and dyskalemia. In neurological patients, usual clinical signs of hyponatremia are frequently confounded with clinical signs of the underlying disease. Natremia absolute value is less important than speed of onset of the trouble. Most often, hyponatremia is associated with hypotonicity and intracellular hyperhydration, which may exacerbate a cerebral edema. Distinction between inappropriate secretion of antidiuretic hormone (SIADH) and cerebral salt wasting syndrome (CSWS) may be difficult and is mainly based on assessment of patients volemia, SIADH being associated with normal or hypervolemia and CSWS with hypovolemia. After subarachnoid haemorrhage, the most common disorder is CSWS. In this case, fluid restriction is strictly prohibited. Treatment of CSWS needs to compensate for the natriuresis and may justify the use of mineralocorticoid. It is important to avoid excessively rapid correction of hypernatremia, with a maximal speed of correction of 0.5 m mol/l/h. Serum sodium monitoring should be mandatory for the first ten postoperative days after pituitary adenoma surgery. Therapeutic barbiturate may be responsible for life threatening dyskalemia.

Seeking new approaches: milrinone in the treatment of cerebral vasospasm.

Cerebral vasospasm and cerebral infarction is not only a potentially devastating complication after cerebral aneurysmal rupture, but because its mechanism is not completely understood, its prevention and treatment cannot be fully effective. Apart from transluminal balloon angioplasty and induced hypertension and hypervolemia, several vasodilating drugs have been used to treat vasospasm, either by intravenous or intra-arterial route, and sometimes by intrathecal route: papaverine, nimodipine, nicardipine, verapamil, milrinone, magnesium, fasudil, colforsin daropate, and sildenafil. Among these available drugs, except for nimodipine, none has proved to be effective and several of these agents may have worrisome side effects [1–3]. Based on the currently available literature, it is not possible to recommend what would be the most effective intraarterial therapy [4]. Hyperdynamic therapy by increasing cardiac output without increasing blood volume and blood pressure is considered the best available medical option for treatment of cerebral vasospasm [5, 6]. Among vasodilating agents, milrinone has the added effect of inotropy. Milrinone is a phosphodiesterase III inhibitor that affects cyclic adenosine monophosphate (cAMP) pathways with both inotropic and vasodilatory effects. Its first use in the treatment of cerebral vasospasm after rupture of intracranial aneurysm has been reported in 2001 [7]. The intra-arterial infusion of milrinone was shown to reverse arterial spasm. Thereafter, its efficacy on vasospasm and hemodynamic safety has been established by several authors and intra-arterial milrinone has gained an increasing interest in cerebral vasospasm treatment [8–10]. In this issue of Neurocritical Care, Lannes et al. [11] from Neurological Hospital McGill University, Montreal, suggest a new approach that ‘‘moved away from volume expansion and routinely induced hypertension’’ and a focus on using of milrinone. They present a retrospective study of a series of 88 patients with symptomatic cerebral vasospasm after aneurysmal rupture, treated with continuous intravenous milrinone (and maintenance of normovolemia and homeostasis) as first line treatment (so called the Montreal Neurological Hospital protocol) [12, 13]. All patients received a standard course of prophylactic nimodipine and a short course of tranexamic acid until the aneurysm was secured. Monitoring of patients with symptomatic vasospasm included an arterial line, a central venous catheter for CVP monitoring, continuous electrocardiographic monitoring, daily electrolytes (that included phosphate and magnesium), complete blood counts and intracranial pressure monitoring if an external ventricular drain was present. The Montreal Neurological Hospital protocol stepwise approach was based on the maintenance of homeostasis and boluses of intravenous milrinone followed by intravenous infusion of milrinone. If neurological deficit persisted, doses of milrinone were increased, followed by norepinephrine continuous infusion to maintain MAP >90 mmHg. If symptoms still persisted, rescue therapy involves emergency angiography and the use of a A. Baumann (&) G. Audibert Neurosurgical Intensive Care Unit, Hôpital Central, Centre Hospitalier Universitaire, Nancy, France e-mail: antoine_baumann@hotmail.com; a.baumann@chu-nancy.fr

Rôle délétère de l’hyperthermie en neuroréanimation ☆

Fever is a secondary brain injury and may worsen neurological prognosis of neurological intensive care unit (NICU) patients. In response to an immunological threat, fever associates various physiological reactions, including hyperthermia. Its definition may vary but the most commonly used threshold is 37.5 degrees C. In animal studies, hyperthermia applied before, during or after cerebral ischemia may increase the volume of ischemic lesions. The mechanism of this effect may include increase in blood brain barrier permeability, increase in excitatory amino acid release and increase in free radical production. In NICU patients, fever is frequent, occurring in up to 20-30% of patients. Moreover, after haemorrhagic stroke, fever has been reported in 40-50% of patients. In half of the patients, fever may be related to an infectious cause but in more than 25% of patients, hyperthermia may be of central origin. After ischemic stroke, hyperthermia during the first 72 hours is associated with an increase in infarct size and increase in morbidity and mortality. This holds true also after subarachnoid haemorrhage. After traumatic brain injury, fever is not related to mortality but may increase morbidity. Whereas no causal link has been established between fever and unfavourable outcome, it seems reasonable to treat hyperthermia in patients suffering from brain injuries. In such patients, antipyretics have a moderate efficacy. In case of failure, they should be replaced by physical cooling techniques.

Talking about patient's values and posthumous organ donation

Dear Editor, In a recent paper Erwin Kompanje [1] stressed the critical importance of complying with the patient’s values when considering the possibility of post-mortem organ donation when no advance choice is available. At a time when many countries consider instituting the presumed consent rule or reinforcing it by doing so without the possibility for the family to testify of the potential donor’s reluctance, Kompanje’s words sound of paramount pertinence. Conversing with many colleagues, it emerges indeed that even under a regimen of presumed consent many families feel naturally entitled to defend their dying or dead loved one’s physical and spiritual interests and speak on his or her behalf. Certainly, posthumous harm could occur when the patient’s own wishes or values are not looked for, are disregarded or not respected [2]. Moreover, families also can be harmed, especially by overlooking the affective or family bond by denying them the right to express, honour and put into practice the values of their departed beloved. So, presumed consent is often viewed by families with much suspicion and the discussion often turns around the question of the most probable opinion of the patient. But this question of substituted judgment as such entails substantial psychological, emotional and cognitive burdens, is morally complex and is often impossible to answer [3]. Having no idea of their loved one’s opinion, many families prefer to oppose organ harvesting. So it is ethically imperative to join with them in seeking the patient’s values and help them to honour values regarding organ donation. In these circumstances, the same approach used for the determination of values previously held by patients when their decision autonomy has definitely and permanently vanished could be very helpful. For Scheunemann et al. [3], the goal is to make authentic decisions, i.e. decisions informed by the knowledge of the patient’s life story and values, always motivated by the respect of who the person was and fitting with his or her history. However, there is little guidance for clinicians to assist families in seeking an authentic depiction of the dead patient’s values. According to the contemporary law philosopher Ronald Dworkin, besides mere immediate experiential interests most individuals have critical interests: they attach importance to do in their life things that they consider as good ones, and to avoid the things they consider as bad, irrespective of the type of experience resulting from the realization of these interests. For Dworkin, it is especially in the pursuit of these critical interests—e.g. values—that an individual reveals his or her personality and makes a judgment on the kind of life he or she wants to have lived [4]. According to Agnieszka Jaworska [5], another philosopher, it is attaching importance to some ideals, something that extends beyond us, things that are greater than only our personal benefit and are included in a broader normative framework—regardless of cost in terms of effort or displeasure—that defines the individual’s values. Explaining these approaches to defining values to bereaved and upset families could help them to disentangle the complex ‘‘pros and cons’’ underlying the assumed opinion of their loved one regarding postmortem organ donation, and finally to keep consistency with the kind of life he or she wanted to live. Because most cultures and religions attach importance to treat persons—even dead—in a Kantian way, i.e. as ends in themselves rather than merely as means to an end, this framework centred on the patient’s values should be consensually accepted in our pluralistic societies [3].

Club de l’AnarlfRôle délétère de l’hyperthermie en neuroréanimationDeleterious role of hyperthermia in neurocritical care☆

Fever is a secondary brain injury and may worsen neurological prognosis of neurological intensive care unit (NICU) patients. In response to an immunological threat, fever associates various physiological reactions, including hyperthermia. Its definition may vary but the most commonly used threshold is 37.5 degrees C. In animal studies, hyperthermia applied before, during or after cerebral ischemia may increase the volume of ischemic lesions. The mechanism of this effect may include increase in blood brain barrier permeability, increase in excitatory amino acid release and increase in free radical production. In NICU patients, fever is frequent, occurring in up to 20-30% of patients. Moreover, after haemorrhagic stroke, fever has been reported in 40-50% of patients. In half of the patients, fever may be related to an infectious cause but in more than 25% of patients, hyperthermia may be of central origin. After ischemic stroke, hyperthermia during the first 72 hours is associated with an increase in infarct size and increase in morbidity and mortality. This holds true also after subarachnoid haemorrhage. After traumatic brain injury, fever is not related to mortality but may increase morbidity. Whereas no causal link has been established between fever and unfavourable outcome, it seems reasonable to treat hyperthermia in patients suffering from brain injuries. In such patients, antipyretics have a moderate efficacy. In case of failure, they should be replaced by physical cooling techniques.

An assessment of advance relatives approach for brain death organ donation

Background: Advance announcement of forthcoming brain death has developed to enable intensivists and organ procurement organisation coordinators to more appropriately, and separately from each other, explain to relatives brain death and the subsequent post-mortem organ donation opportunity. Research aim: The aim was to assess how potentially involved healthcare professionals perceived ethical issues surrounding the strategy of advance approach. Research design: A multi-centre opinion survey using an anonymous self-administered questionnaire was conducted in the six-member hospitals of the publicly funded East of France regional organ and tissue procurement network called ‘Prélor’. Participants: The study population comprised 460 physicians and nurses in the Neurosurgical, Surgical and Medical Intensive Care Units, the Stroke Units and the Emergency Departments. Ethical considerations: The project was approved by the board of the Lorraine University Diploma in Medical Ethics and the Prélor Network administrators. Main findings: A slight majority of 53.5% of respondents had previously participated in an advance relatives approach: 83% of the physicians and 42% of the nurses. A majority of healthcare professionals (68%) think that the main justification for advance relatives approach is the comprehensive care of the dying patient and the research of his or her most likely opinion (74%). The misunderstanding of the related issues by relatives is an obstacle for 47% of healthcare professionals and 51% think that the answer given by the relatives regarding the most likely opinion of the person regarding post-mortem organ donation really corresponds to the person opinion in only 50% of the cases or less. Conclusion: Time given by advance approach should be employed to help and enable relatives to authentically bear the values and interests of the potential donor in the post-mortem organ donation discussion. Nurses’ attendance of advance relatives approach seems necessary to enable them to optimally support the families facing death and post-mortem organ donation issues.