M. Kamran Athar

Association between hyperoxia and mortality after stroke: a multicenter cohort study.

Objective:To test the hypothesis that hyperoxia was associated with higher in-hospital mortality in ventilated stroke patients admitted to the ICU. Design:Retrospective multicenter cohort study. Setting:Primary admissions of ventilated stroke patients with acute ischemic stroke, subarachnoid hemorrhage, and intracerebral hemorrhage who had arterial blood gases within 24 hours of admission to the ICU at 84 U.S. ICUs between 2003 and 2008. Patients were divided into three exposure groups: hyperoxia was defined as PaO2 ≥300 mm Hg (39.99 kPa), hypoxia as any PaO2<60 mm Hg (7.99 kPa) or PaO2/FiO2 ratio ⩽300, and normoxia, not defined as hyperoxia or hypoxia. The primary outcome was in-hospital mortality. Participants:Two thousand eight hundred ninety-four patients. Methods:Patients were divided into three exposure groups: hyperoxia was defined as PaO2 more than or equal to 300 mm Hg (39.99 kPa), hypoxia as any PaO2 less than 60 mm Hg (7.99 kPa) or PaO2/FIO2 ratio less than or equal to 300, and normoxia, not defined as hyperoxia or hypoxia. The primary outcome was in-hospital mortality. Interventions:Exposure to hyperoxia. Results:Over the 5-year period, we identified 554 ventilated patients with acute ischemic stroke (19%), 936 ventilated patients with subarachnoid hemorrhage (32%), and 1,404 ventilated patients with intracerebral hemorrhage (49%) of whom 1,084 (38%) were normoxic, 1,316 (46%) were hypoxic, and 450 (16%) were hyperoxic. Mortality was higher in the hyperoxia group as compared with normoxia (crude odds ratio 1.7 [95% CI 1.3-2.1]; p < 0.0001) and hypoxia groups (crude odds ratio, 1.3 [95% CI, 1.1–1.7]; p < 0.01). In a multivariable analysis adjusted for admission diagnosis, other potential confounders, the probability of being exposed to hyperoxia, and hospital-specific effects, exposure to hyperoxia was independently associated with in-hospital mortality (adjusted odds ratio, 1.2 [95% CI, 1.04–1.5]). Conclusion:In ventilated stroke patients admitted to the ICU, arterial hyperoxia was independently associated with in-hospital death as compared with either normoxia or hypoxia. These data underscore the need for studies of controlled reoxygenation in ventilated critically ill stroke populations. In the absence of results from clinical trials, unnecessary oxygen delivery should be avoided in ventilated stroke patients.

Significance of arterial hyperoxia and relationship with case fatality in traumatic brain injury: a multicentre cohort study

Objective In this retrospective multi-centre cohort study, we tested the hypothesis that hyperoxia was not associated with higher in-hospital case fatality in ventilated traumatic brain injury (TBI) patients admitted to the intensive care unit (ICU). Methods Admissions of ventilated TBI patients who had arterial blood gases within 24 h of admission to the ICU at 61 US hospitals between 2003 and 2008 were identified. Hyperoxia was defined as PaO2 ≥300 mm Hg (39.99 kPa), hypoxia as any PaO2 <60 mm Hg (7.99 kPa) or PaO2/FiO2 ratio ≤300 and normoxia, not defined as hyperoxia or hypoxia. The primary outcome was in-hospital case fatality. Results Over the 5-year period, we identified 1212 ventilated TBI patients, of whom 403 (33%) were normoxic, 553 (46%) were hypoxic and 256 (21%) were hyperoxic. The case-fatality was higher in the hypoxia group (224/553 [41%], crude OR 2.3, 95% CI 1.7-3.0, p<.0001) followed by hyperoxia (80/256 [32%], crude OR 1.5, 95% CI 1.1-2.5, p=.01) as compared to normoxia (87/403 [23%]). In a multivariate analysis adjusted for other potential confounders, the probability of being exposed to hyperoxia and hospital-specific characteristics, exposure to hyperoxia was independently associated with higher in-hospital case fatality adjusted OR 1.5, 95% CI 1.02-2.4, p=0.04. Conclusions In ventilated TBI patients admitted to the ICU, arterial hyperoxia was independently associated with higher in-hospital case fatality. In the absence of results from clinical trials, unnecessary oxygen delivery should be avoided in critically ill ventilated TBI patients.

Hospital mortality in primary admissions of septic patients with status epilepticus in the United States

Objective:To determine the prevalence of status epilepticus, associated factors, and relationship with in-hospital mortality in primary admissions of septic patients in the United States. Design:Cross-sectional study. Setting:Primary admissions of adult patients more than 18 years old with a diagnosis of sepsis and status epilepticus from 1988 to 2008 identified through the Nationwide Inpatient Sample. Participants:A total of 7,669,125 primary admissions of patients with sepsis. Interventions:None. Results:During the 21-year study period, the prevalence of status epilepticus in primary admissions of septic patients increased from 0.1% in 1988 to 0.2% in 2008 (p < 0.001). Status epilepticus was also more common among later years, younger admissions, female gender, Black race, rural hospital admissions, and in those patients with organ dysfunctions. Mortality of primary sepsis admissions decreased from 20% in 1988 to 18% in 2008 (p < 0.001). Mortality in status epilepticus during sepsis decreased from 43% in 1988 to 28% in 2008. In-hospital mortality after admissions for sepsis was associated with status epilepticus, older age, and Black and Native American/Eskimo race; patients admitted to a rural or urban private hospitals; and patients with organ dysfunctions. Conclusion:Our analysis demonstrates that status epilepticus after admission for sepsis in the United States was rare. Despite an overall significant reduction in mortality after admission for sepsis, status epilepticus carried a higher risk of death. More aggressive electrophysiological monitoring and a high level of suspicion for the diagnosis of status epilepticus may be indicated in those patients with central nervous system organ dysfunction after sepsis.

Neurologic Aspects of Cardiac Emergencies

In this review, cardiac arrest is discussed, with a focus on neuroprognostication and the emerging data, with regard to identifying more accurate predictors of neurologic outcomes in the era of therapeutic hypothermia. Topics discussed include recent controversies with regard to targeted temperature management in comatose survivors of cardiac arrest; neurologic complications associated with surgical disease and procedures, namely aortic dissection, infective endocarditis, left ventricular assist devices, and coronary artery bypass grafting; and the cause, pathogenesis, and management of neurogenic stunned myocardium.

Early Ambulation in Patients With External Ventricular Drains: Results of a Quality Improvement Project

Introduction: Prolonged immobility in patients in the intensive care unit (ICU) can lead to muscle wasting and weakness, longer hospital stays, increased number of days in restraints, and hospital-acquired infections. Increasing evidence demonstrates the safety and feasibility of early mobilization in the ICU. However, there is a lack of evidence in the safety and feasibility of mobilizing patients with external ventricular drains (EVDs). The purpose of this study was to determine the safety and feasibility of early mobility in this patient population. Methods: We conducted a prospective, observational study. All patients in the study were managed with standard protocols and procedures practiced in our ICU including early mobility. Patients with an EVD who received early mobilization were awake and following commands, had a Lindegaard ratio <3.0 or middle cerebral artery (MCA) mean flow velocity <120 cm/s, a Mean Arterial Pressure (MAP) > 80 mm Hg, and an intracranial pressure consistently <20 mm Hg. Data were collected by physical therapists at the time of encounter. Results: Ninety patients with a total of 185 patient encounters were recorded over a 12-month period. The average time between EVD placement and physical therapy (PT) session was 8.3 ± 5.5 days. In 149 (81%) encounters, patients were at least standing or better. Patients were walking with assistance or better in 99 (54%) encounters. There were 4 (2.2%) adverse events recorded during the entire study. Conclusion: This observational study suggests that PT is feasible in patients with EVDs and can be safely tolerated. Further research is warranted in a larger patient population conducted prospectively to assess the potential benefit of early mobility in this patient population.

Guillain-Barre Syndrome with Lymphocytic Pleocytosis of the CSF

Introduction: Guillain-Barre typically presents as a symmetric ascending weakness with areflexia. The cerebrospinal fluid typically shows albuminocytologic dissociation. In this case, we present an atypical presentation of severe Guillain-Barre with cerebrospinal fluid exhibiting lymphocytic pleocytosis. Case report: 60-year-old man presented with progressive lower- extremity weakness that progressed to involve respiratory failure and areflexia over several weeks. Electromyography showed both demyelinating and axonal features. Lumbar puncture revealed a lymphocytic pleocytosis. Given the abnormalities on these tests with a clinical picture of Guillain-Barre the patient underwent extensive paraneoplastic testing and full neuro-axis imaging. Imaging revealed abnormal enhancement of ventral and dorsal nerve roots which is consistent with Guillain-Barre. Conclusion: In conclusion, a diagnosis of Guillain-Barre syndrome may still be considered in a patient with clinical findings and EMG studies consistent with GBS but with a CSF profile that does not show the typical albuminocytologic dissociation. However, all other causes of CSF lymphocytic pleocytosis must be ruled out before coming to this conclusion.

Management of Severe TBI-A Review of Recent Literature

INTRODUCTION Traumatic Brain Injury (TBI) is the result of sudden trauma causing damage to the brain. TBI can occur when the head strongly and abruptly changes direction or contacts an object, or when an object penetrates the skull and brain tissue. (Figure 1 – TBI). CDC estimated that in 2010, TBI, alone and in conjunction with other injuries, accounted for approximately 2.5 million ED visits, hospitalizations, and deaths in the United States. Children aged 0–4 years, adolescents aged 15–19 years, and, most significantly, adults aged 75 years and older are the most likely to sustain a TBI and seek medical care1. The leading cause of non-fatal TBI in the U.S. is falls and the leading cause of TBI-related fatalities is motor vehicle accidents2.