Lioudmila V. Karnatovskaia

Therapeutic Hypothermia for Neuroprotection: History, Mechanisms, Risks, and Clinical Applications

The earliest recorded application of therapeutic hypothermia in medicine spans about 5000 years; however, its use has become widespread since 2002, following the demonstration of both safety and efficacy of regimens requiring only a mild (32°C-35°C) degree of cooling after cardiac arrest. We review the mechanisms by which hypothermia confers neuroprotection as well as its physiological effects by body system and its associated risks. With regard to clinical applications, we present evidence on the role of hypothermia in traumatic brain injury, intracranial pressure elevation, stroke, subarachnoid hemorrhage, spinal cord injury, hepatic encephalopathy, and neonatal peripartum encephalopathy. Based on the current knowledge and areas undergoing or in need of further exploration, we feel that therapeutic hypothermia holds promise in the treatment of patients with various forms of neurologic injury; however, additional quality studies are needed before its true role is fully known.

The spectrum of psychocognitive morbidity in the critically ill: a review of the literature and call for improvement.

OBJECTIVE The objective of the study is to review the cognitive and psychiatric dysfunction experienced by critically ill patients during and after hospitalization. METHODS A structured PubMed search identified studies and reports in English pertaining to intensive care unit (ICU)-related cognitive and psychological dysfunction, known risk factors, and treatment modalities. DATA SYNTHESIS This article summarizes recent literature on psychological sequelae experienced by critically ill patients including delirium, cognitive impairment, acute stress disorder, posttraumatic stress disorder, anxiety, and depression. Known risk factors for cognitive dysfunction and psychological trauma are discussed, encompassing clinical, demographic, socioeconomic, and psychiatric domains as well as the memories of the ICU stay. Specific treatment and prevention modalities are discussed including post-ICU physical rehabilitation and psychotherapeutic interventions as well as interventions available to patients still in the ICU, including early mobilization, minimization of sedation, improved sleep hygiene, and available psychological interventions. CONCLUSIONS We propose a paradigm change highlighting the need for interventions focused on early psychological support applied in parallel with stabilization of physiologic status in the ICU.

Cardiac arrest in a 21-year-old man after ingestion of 1,3-DMAA-containing workout supplement.

Dietary supplements containing 1,3-dimethylamylamine (DMAA) have been determined to be illegal by the Food and Drug Administration (FDA); although banned, the products are still widely available for purchase. Adverse effects reported include cardiac arrest, hemorrhagic stroke, and death. Nonetheless, such products remain popular among young people because of advertised claims of exercise performance enhancement and fat burning. We describe a case of a young man who took such a supplement and suffered a cardiac arrest. Notably, the product consumed was not on the FDA list of substances containing DMAA. This case highlights the importance for clinicians to be aware of the potential harm of the DMAA-containing products by maintaining a high index of suspicion in otherwise healthy individuals presenting with cardiac arrest. It is of particular importance to sports medicine physicians who are most involved in education and counseling of patients potentially at risk of taking such products.

Effect of Therapeutic Hypothermia on Gas Exchange and Respiratory Mechanics: A Retrospective Cohort Study

Targeted temperature management (TTM) may improve respiratory mechanics and lung inflammation in acute respiratory distress syndrome (ARDS) based on animal and limited human studies. We aimed to assess the pulmonary effects of TTM in patients with respiratory failure following cardiac arrest. Retrospective review of consecutive cardiac arrest cases occurring out of hospital or within 24 hours of hospital admission (2002-2012). Those receiving TTM (n=44) were compared with those who did not (n=42), but required mechanical ventilation (MV) for at least 4 days following the arrest. There were no between-group differences in age, gender, body mass index, APACHE II, or fluid balance during the study period. The TTM group had lower ejection fraction, Glasgow Coma Score, and more frequent use of paralytics. Matched data analyses (change at day 4 compared with baseline of the individual subject) showed favorable, but not statistically significant trends in respiratory mechanics endpoints (airway pressure, compliance, tidal volume, and PaO2/FiO2) in the TTM group. The PaCO2 decreased significantly more in the TTM group, as compared with controls (-12 vs. -5 mmHg, p=0.02). For clinical outcomes, the TTM group consistently, although not significantly, did better in survival (59% vs. 43%) and hospital length of stay (12 vs. 15 days). The MV duration and Cerebral Performance Category score on discharge were significantly lower in the TTM group (7.3 vs. 10.7 days, p=0.04 and 3.2 vs. 4, p=0.01). This small retrospective cohort suggests that the effect of TTM ranges from equivalent to favorable, compared with controls, for the specific respiratory and clinical outcomes in patients with respiratory failure following cardiac arrest.

Obstructive sleep apnea, obesity, and the development of acute respiratory distress syndrome.

BACKGROUND Obstructive sleep apnea (OSA) may increase the risk of respiratory complications and acute respiratory distress syndrome (ARDS) among surgical patients. OSA is more prevalent among obese individuals; obesity can predispose to ARDS. HYPOTHESIS It is unclear whether OSA independently contributes towards the risk of ARDS among hospitalized patients. METHODS This is a pre-planned retrospective subgroup analysis of the prospectively identified cohort of 5,584 patients across 22 hospitals with at least one risk factor for ARDS at the time of hospitalization from a trial by the US Critical Illness and Injury Trials Group designed to validate the Lung Injury Prediction Score. A total of 252 patients (4.5%) had a diagnosis of OSA at the time of hospitalization; of those, 66% were obese. Following multivariate adjustment in the logistic regression model, there was no significant relationship between OSA and development of ARDS (OR = 0.65, 95%CI = 0.32-1.22). However, body mass index (BMI) was associated with subsequent ARDS development (OR = 1.02, 95%CI = 1.00-1.04, p = 0.03). Neither OSA nor BMI affected mechanical ventilation requirement or mortality. CONCLUSIONS Prior diagnosis of OSA did not independently affect development of ARDS among patients with at least one predisposing condition, nor the need for mechanical ventilation or hospital mortality. Obesity appeared to independently increase the risk of ARDS.

The influence of prehospital systemic corticosteroid use on development of acute respiratory distress syndrome and hospital outcomes.

Objective:The role of systemic corticosteroids in pathophysiology and treatment of acute respiratory distress syndrome is controversial. Use of prehospital systemic corticosteroid therapy may prevent the development of acute respiratory distress syndrome and improve hospital outcomes. Design:This is a preplanned retrospective subgroup analysis of the prospectively identified cohort from a trial by the U.S. Critical Illness and Injury Trials Group designed to validate the Lung Injury Prediction Score. Setting:Twenty-two acute care hospitals. Patients:Five thousand eighty-nine patients with at least one risk factor for acute respiratory distress syndrome at the time of hospitalization. Intervention:Propensity-based analysis of previously recorded data. Measurements and Main Results:Three hundred sixty-four patients were on systemic corticosteroids. Prevalence of acute respiratory distress syndrome was 7.7% and 6.9% (odds ratio, 1.1 [95% CI, 0.8–1.7]; p = 0.54) for patients on systemic corticosteroid and not on systemic corticosteroids, respectively. A propensity for being on systemic corticosteroids was derived through logistic regression by using all available covariates. Subsequently, 354 patients (97%) on systemic corticosteroids were matched to 1,093 not on systemic corticosteroids by their propensity score for a total of 1,447 patients in the matched set. Adjusted risk for acute respiratory distress syndrome (odds ratio, 0.96 [95% CI, 0.54–1.38]), invasive ventilation (odds ratio, 0.84 [95% CI, 0.62–1.12]), and in-hospital mortality (odds ratio, 0.97 [95% CI, 0.63–1.49]) was then calculated from the propensity-matched sample using conditional logistic regression model. No significant associations were present. Conclusions:Prehospital use of systemic corticosteroids neither decreased the development of acute respiratory distress syndrome among patients hospitalized with at one least risk factor, nor affected the need for mechanical ventilation or hospital mortality.

Stress-induced cardiomyopathy complicating a stroke caused by an air embolism.

Systemic air embolism is a very rare (<0.1%) complication of computed tomography-guided transthoracic needle aspiration and can result in serious neurological and/or cardiac sequelae. Stroke and stress cardiomyopathy can have a variety of etiologies; however, an association of Takotsubo cardiomyopathy with cerebrovascular events precipitated by an air embolus has not been reported. We report a patient with stress-induced cardiomyopathy after an air embolus-induced stroke. The patient was managed with hyperbaric oxygenation and her cardiomyopathy was initially treated as per the acute coronary syndrome protocol until coronary angiography confirmed patent arteries. We review the pathophysiology and management recommendations for both events. Prompt recognition of air embolism-induced cerebrovascular events and stress cardiomyopathy by clinicians is imperative to the timely initiation of appropriate management and a successful treatment outcome.

Therapeutic hypothermia and targeted temperature management after cardiac arrest.

Author Affiliations: Cognitive Neurology and Alzheimer’s Disease Center, Northwestern University Feinberg School of Medicine, Chicago, Illinois (Rogalski, Wieneke, Bigio, Weintraub, Mesulam); Department of Preventative Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois (Rademaker); Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, Illinois (Bigio); Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, Illinois (Weintraub); Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois (Mesulam).

Sepsis: A Review for the Neurohospitalist

Sepsis represents a major challenge in medicine. It begins as a systemic response to infection that can affect virtually any organ system, including the central and peripheral nervous systems. Akin to management of stroke, early recognition and treatment of sepsis are just as crucial to a successful outcome. Sepsis can precipitate myasthenic crisis and lead to encephalopathy and critical illness neuropathy. Stroke and traumatic brain injury can predispose a patient to develop sepsis, whereas Guillain-Barré syndrome is similarly not uncommon following infection. This review article will first describe the essential principles of sepsis recognition, pathophysiology, and management and will then briefly cover the neurologic aspects associated with sepsis. Vigilant awareness of the clinical features of sepsis and timeliness of intervention can help clinicians prevent progression of this disease to a multisystem organ failure, which can be difficult to reverse even after the original source of infection is under control.

Perspectives of physicians and nurses on identifying and treating psychological distress of the critically ill

Purpose: Survivors of critical illness are frequently unable to return to their premorbid level of psychocognitive functioning following discharge. Therefore, we aimed to evaluate the burden of psychological trauma experienced by patients in the intensive care unit (ICU) as perceived by clinicians to assess factors that can impede its recognition and treatment in the ICU. Materials and methods: Two distinct role‐specific Web‐based surveys were administered to critical care physicians and nurses in medical and surgical ICUs of 2 academic medical centers. Responses were analyzed in the domains of psychological trauma, exacerbating/mitigating factors, and provider‐patient communication. Results: A survey was completed by 43 physicians and 55 nurses with a response rate of 62% and 37%, respectively. Among physicians, 65% consistently consider the psychological state of the patient in decision making; 77% think it is important to introduce a system to document psychological state of ICU patients; 56% would like to have more time to communicate with patients; 77% consistently spend extra time at bedside besides rounds and often hold patients hand/reassure them. Notably, for the question about the average level of psychological stress experienced by a patient in the ICU (with 0 = no stress and 100 = worst stress imaginable) during initial treatment stage and by the end of the ICU stay, median assessment by both physicians and nurses was 80 for the initial stress level and 68 for the stress level by the end of the ICU stay. Among nurses, 69% always try to minimize noise and 73% actively promote patients rest. Physicians and nurses provided multiple specific suggestions for improving ICU environment and communication. Conclusions: Both physicians and nurses acknowledge that they perceive that critically ill patients experience a high level of psychological stress that persists throughout their period of illness. Improved understanding of this phenomenon is needed to design effective therapeutic interventions. Although the lack of time is identified as significant barrier to ameliorating patients psychological stress, the majority of clinicians indicate that they attempt to provide interventions to achieve this goal.