A challenging clinical conundrum arises in severe traumatic brain injury patients who develop intractable intracranial hypertension. For these patients, high morbidity interventions such as surgical ...decompression and barbiturate coma have to be considered against a backdrop of uncertain outcomes including prolonged states of disordered consciousness and severe disability. The clinical evidence available to guide shared decision-making is mainly limited to one randomized controlled trial, the RESCUEicp. However, since the publication of this trial significant controversy has been ongoing over the interpretation of the results. Is the mortality benefit from surgery merely a trade off for unacceptable long-term disability? How should treatment options, possible outcomes, and results from the trial be communicated to surrogates? How do we incorporate patient values into forming plans of care? The aim of this article is to sketch an approach based on insights from
Decision Theory
, and specifically
deciding under uncertainty
. The mainstream normative decision theory, Expected Utility (EU) theory, essentially says that,
in situ
ations of uncertainty, one should prefer the option with greatest expected desirability or value. The steps required to compute expected utilities include listing the possible outcomes of available interventions, assigning each outcome a utility ranking representing an individual patient's preferences, and a conditional probability given each intervention. This is a conceptual framework meant to supplement, and enhance shared decision making by assuring that patient values are elicited and incorporated, the possible range and nature of outcomes is discussed, and finally by attempting to connect best available means to patient-individualized ends.
Abstract Shock is a systemic form of acute circulatory failure leading to cellular dysoxia and death. Such a state of aerobic metabolism failure also underlies neuronal cell death in severe traumatic ...brain injury. It is becoming increasingly recognized that ischemic hypoxia is not the sole mechanism and that multiple alternate cooperating mechanisms may be responsible for compromising neuronal oxidative metabolism. These different mechanisms can be usefully understood via analysis of the classic subdivisions of tissue hypoxia. This approach could lead to an alternative treatment paradigm towards cerebral oxygen metabolic rate (CMRO2 )-targeting instead of the traditional targets of intracranial and perfusion pressures.
A relationship between reduced brain tissue oxygenation and poor outcome following severe traumatic brain injury has been reported in observational studies. We designed a Phase II trial to assess ...whether a neurocritical care management protocol could improve brain tissue oxygenation levels in patients with severe traumatic brain injury and the feasibility of a Phase III efficacy study.
Randomized prospective clinical trial.
Ten ICUs in the United States.
One hundred nineteen severe traumatic brain injury patients.
Patients were randomized to treatment protocol based on intracranial pressure plus brain tissue oxygenation monitoring versus intracranial pressure monitoring alone. Brain tissue oxygenation data were recorded in the intracranial pressure -only group in blinded fashion. Tiered interventions in each arm were specified and impact on intracranial pressure and brain tissue oxygenation measured. Monitors were removed if values were normal for 48 hours consecutively, or after 5 days. Outcome was measured at 6 months using the Glasgow Outcome Scale-Extended.
A management protocol based on brain tissue oxygenation and intracranial pressure monitoring reduced the proportion of time with brain tissue hypoxia after severe traumatic brain injury (0.45 in intracranial pressure-only group and 0.16 in intracranial pressure plus brain tissue oxygenation group; p < 0.0001). Intracranial pressure control was similar in both groups. Safety and feasibility of the tiered treatment protocol were confirmed. There were no procedure-related complications. Treatment of secondary injury after severe traumatic brain injury based on brain tissue oxygenation and intracranial pressure values was consistent with reduced mortality and increased proportions of patients with good recovery compared with intracranial pressure-only management; however, the study was not powered for clinical efficacy.
Management of severe traumatic brain injury informed by multimodal intracranial pressure and brain tissue oxygenation monitoring reduced brain tissue hypoxia with a trend toward lower mortality and more favorable outcomes than intracranial pressure-only treatment. A Phase III randomized trial to assess impact on neurologic outcome of intracranial pressure plus brain tissue oxygenation-directed treatment of severe traumatic brain injury is warranted.
Management of volume status, arterial blood pressure, and cardiac output are core elements in approaching the patients with aneurysmal subarachnoid hemorrhage (SAH). For the prevention and treatment ...of delayed cerebral ischemia (DCI), euvolemia is advocated and caution is made towards the avoidance of hypervolemia. Induced hypertension and cardiac output augmentation are the mainstays of medical management during active DCI, whereas the older triple-H paradigm has fallen out of favor due to lack of demonstrable physiological or clinical benefits and serious concern for adverse effects such as pulmonary edema and multiorgan system dysfunction. Furthermore, insight into clinical hemodynamics of patients with SAH becomes salient when one considers the frequently associated cardiac and pulmonary manifestations of the disease such as SAH-associated cardiomyopathy and neurogenic pulmonary edema. In terms of fluid and volume targets, less attention has been paid to dynamic markers of fluid responsiveness despite the well-established, in the general critical care literature, superiority of these as compared to traditionally used static markers such as central venous pressure (CVP). Based on this literature and sound pathophysiologic reasoning, reliance on static markers (such as CVP) is unjustified when one attempts to assess strategies augmenting stroke volume (SV), arterial blood pressure, and oxygen delivery. There are several options for continuous bedside cardiorespiratory monitoring and optimization of SAH patients. We, here, review a noninvasive monitoring technique based on thoracic bioreactance and focusing on continuous cardiac output and fluid responsiveness markers.
Background
Withdrawal of life-sustaining treatment (WOLST) is the leading proximate cause of death in patients with
perceived devastating brain injury
(PDBI). There are reasons to believe that a ...potentially significant proportion of WOLST decisions, in this setting, are premature and guided by a number of assumptions that falsely confer a sense of certainty.
Method
This manuscript proposes that these assumptions face serious challenges, and that we should replace unwarranted certainty with an appreciation for the great degree of multi-dimensional uncertainty involved. The article proceeds by offering a taxonomy of uncertainty in PDBI and explores the key role that uncertainty as a cognitive state, may play into how WOLST decisions are reached.
Conclusion
In order to properly share decision-making with families and surrogates of patients with PDBI, we will have to acknowledge, understand, and be able to communicate the great degree of uncertainty involved.
Informed consent (IC) is an ethical and legal requirement grounded in the principle of autonomy. Cognitive impairment may often interfere with decision-making capacity necessitating alternative ...models of ethically sound deliberation. In cases where the patient lacks decision-making capacity, one must determine the appropriate decision-maker and the criteria used in making a medical decision appropriate for the patient. In this article, I critically discuss the traditional approaches of IC, advance directives, substituted judgment, and best interests. A further suggestion is that thinking about sufficient reasons for or against a course of action is a conceptual enrichment in addition to the concepts of interests and well-being. Finally, I propose another model of collective consensus-seeking decision-making.
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