The role of head computer tomographic scans on the management of MICU patients with neurological dysfunction

Diagnostic Approach to the Patient with Altered Mental Status

Acute encephalopathy is a common presenting symptom in the emergency room and complicates many hospital and intensive care unit admissions. The evaluation of patients with encephalopathy poses several challenges: limited history and examination due to the patient's mental status, broad differential diagnosis of systemic and neurologic etiologies, low yield of neurodiagnostic testing due to the high base rate of systemic causes, and the importance of identifying less common neurologic causes of encephalopathy that can be life-threatening if not identified and treated. This article discusses the differential diagnosis of acute encephalopathy, presents an approach to the history and examination in a patient with encephalopathy, reviews the literature on the yield of neurodiagnostic testing in this population, and provides a diagnostic framework for the evaluation of patients with altered mental status.

Evaluation of Paroxysmal Events in Critically Ill Patients: Relationship of Primary Diagnosis to Long-Term Electroencephalogram Yield

Continuous EEG (cEEG) is indicated for the workup of paroxysmal events. We aimed to assess whether primary admission diagnoses predict the yield of cEEG when ordered for evaluating paroxysmal events. We identified patients in the ICU who underwent at least 6 hours of cEEG monitoring to evaluate paroxysmal events. Primary admission diagnoses were categorized into neurological or non-neurological conditions. cEEG results were dichotomized into presence or absence of epileptiform discharges. We identified 159 recordings that were obtained for the evaluation of paroxysmal events. Most patients (n = 100, 63%) were admitted with primary admission diagnoses of neurological disorders, such as ischemic stroke, or intracranial hemorrhage. We found that patients with primary neurological conditions were more likely to have brain surgeries, abnormal brain imaging, and focal neurological deficits on examination compared to those with primary non-neurological conditions. However, there was no significant difference in the prevalence of epileptiform discharges in cEEG among patients with primary diagnoses of neurological or non-neurological disorders. These results suggest that cEEG is often necessary to evaluate paroxysmal events, even among patients without primary neurological disorders.

Diagnostic yield of CT head in delirium and altered mental status-A systematic review and meta-analysis

BACKGROUND

CT head is commonly performed in the setting of delirium and altered mental status (AMS), with variable yield. We aimed to evaluate the yield of CT head in hospitalized patients with delirium and/or AMS across a variety of clinical settings and identify factors associated with abnormal imaging.

METHODS

We included studies in adult hospitalized patients, admitted to the emergency department (ED) and inpatient medical unit (grouped together) or the intensive care unit (ICU). Patients had a diagnosis of delirium/AMS and underwent a CT head that was classified as abnormal or not. We searched Medline, Embase and other databases (informed by PRISMA guidelines) from inception until November 11, 2021. Studies that were exclusively performed in patients with trauma or a fall were excluded. A meta-analysis of proportions was performed; the pooled proportion of abnormal CTs was estimated using a random effects model. Heterogeneity was determined via the I² statistic. Factors associated with an abnormal CT head were summarized qualitatively.

RESULTS

Forty-six studies were included for analysis. The overall yield of CT head in the inpatient/ED was 13% (95% CI: 10.2%-15.9%) and in ICU was 17.4% (95% CI: 10%-26.3%), with considerable heterogeneity (I² 96% and 98% respectively). Heterogeneity was partly explained after accounting for study region, publication year, and representativeness of the target population. Yield of CT head diminished after year 2000 (19.8% vs. 11.1%) and varied widely depending on geographical region (8.4%-25.9%). The presence of focal neurological deficits was a consistent factor that increased yield.

CONCLUSION

Use of CT head to diagnose the etiology of delirium and AMS varied widely and yield has declined. Guidelines and clinical decision support tools could increase the appropriate use of CT head in the diagnostic etiology of delirium/AMS.

Therapeutic Approaches to the Neurologic Manifestations of COVID-19

As of May 2022, there have been more than 527 million infections with severe acute respiratory disease coronavirus type 2 (SARS-CoV-2) and over 6.2 million deaths from Coronavirus Disease 2019 (COVID-19) worldwide. COVID-19 is a multisystem illness with important neurologic consequences that impact long-term morbidity and mortality. In the acutely ill, the neurologic manifestations of COVID-19 can include distressing but relatively benign symptoms such as headache, myalgias, and anosmia; however, entities such as encephalopathy, stroke, seizures, encephalitis, and Guillain-Barre Syndrome can cause neurologic injury and resulting disability that persists long after the acute pulmonary illness. Furthermore, as many as one-third of patients may experience persistent neurologic symptoms as part of a Post-Acute Sequelae of SARS-CoV-2 infection (Neuro-PASC) syndrome. This Neuro-PASC syndrome can affect patients who required hospitalization for COVID-19 or patients who did not require hospitalization and who may have had minor or no pulmonary symptoms. Given the large number of individuals affected and the ability of neurologic complications to impair quality of life and productivity, the neurologic manifestations of COVID-19 are likely to have major and long-lasting personal, public health, and economic consequences. While knowledge of disease mechanisms and therapies acquired prior to the pandemic can inform us on how to manage patients with the neurologic manifestations of COVID-19, there is a critical need for improved understanding of specific COVID-19 disease mechanisms and development of therapies that target the neurologic morbidities of COVID-19. This current perspective reviews evidence for proposed disease mechanisms as they inform the neurologic management of COVID-19 in adult patients while also identifying areas in need of further research.

Rapid Response: To Scan or Not to Scan? The Utility of Noncontrast CT Head for Altered Mental Status

OBJECTIVES

The aims of the study were the following: (1) to determine how often computed tomography (CT) scans of the head are obtained on rapid responses called for altered mental status (AMS), (2) to determine whether CT imaging of the head is required during all rapid responses called for AMS, (3) to determine which patients would benefit from CT scans of the head in this setting, (4) to note whether an adequate neurologic exam was documented, (5) to determine the cost of CT scans that did not change management, and (6) to examine the role of medications leading to AMS.

METHODS

The study was a retrospective chart review at Abington Jefferson Hospital. Data collected included the age, sex, time of rapid response, clinical condition of the patient, whether an arterial blood gas and blood glucose were done, and whether a neurological exam was documented in the resident's rapid response team note. The patien's medications were also reviewed. Computed tomography scan findings as well as changes made in a patient's care as a result of the scan were recorded. Any findings that did not lead to a change in management were considered a "negative" scan.

RESULTS

Overall, 610 rapid responses were activated from January to August 2016. One hundred four (17.04%) of the total rapid responses were for AMS and 83 (79.8%) of these patients underwent noncontrast CT scan of the head. The mean (SD) age of the patients was 74.7 (13.6) years. A total of 56.6% were female. The most frequent clinical conditions documented at the time of rapid responses were noted as confused (33.7%, 28/83), either lethargic or unconscious (32.5%, 27/83), and concern for stroke (21.7%, 18/83). A total of 96.4% (80/83) of the CT scans done were negative for any acute changes. The three patients with positive scans (3/83) had a change in management as a result of the scans. If patients with symptoms concerning for stroke and unconscious patients are excluded, the total number of remaining patients is 56. Of these, zero patients had a positive scan. A total of 64.7% of the rapid response teams were activated either in the afternoon (31.3%) or at night (33.7%). A total of 33.7% had a complete neurological exam documented. A total of 66.2% were either incomplete (34.9%) or absent (31.3%). Sixty percent of the patients who had a CT head for AMS also had a blood sugar checked at bedside. Thirty-eight percent had an arterial blood gas. More than half the patients were taking one or more sedating medications (45/83, 57.8%). Most patients were not on anticoagulants (79.5%).

CONCLUSIONS

The findings of this study suggest that CT scan of the head is useful in older patients, patients with symptoms concerning for stroke, or cases of sudden onset of impaired consciousness. Noncontrast CT scans of the head are not useful for other presentations of AMS.

Analysis of emergency head computed tomography in critically ill oncological patients

BACKGROUND

Critically ill cancer patients have an increased risk of developing acute neurological signs. The study objective was to evaluate the use and the usefulness of emergency head computed tomography (EHCT) in this category of patients.

PATIENTS AND METHODS

This retrospective, single-centre, cohort study included patients with EHCT performed during Intensive Care Unit (ICU) admission for a period of three years. Indications, imagistic findings, type of malignancy, and outcome were evaluated to identify diagnostic yield and correlations between abnormal findings on positive scans, malignancy type, and mortality rate.

RESULTS

Sixty-four EHCTs were performed in 54 critically ill cancer patients, with 32 scans (50%) showing previously unknown lesions and considered to be positive. The most frequent abnormal findings were ischemic (15 EHCTs, 47%) and haemorrhagic (13 EHCTs, 40%) lesions. Thirty-eight EHCTs (59%) were indicated for altered mental status, with a positivity rate of 50%. Eighteen EHCTs (48%) were performed in hematological malignancy patients: 9 (50%) of which were positive with 8/9 (89%) displaying hemorrhagic lesions. Twenty EHCTs were performed in solid tumour patients, 10 (50%) of which were positive, with 9/10 (90%) displaying ischemic lesions. Out of 54 patients, 30 (55%) died during ICU stay. The mortality rate was higher in patients with hematological malignancies and positive EHCT (78% vs. 58%).

CONCLUSIONS

Diagnostic yield of EHCT in critically ill cancer patients is much higher than in other categories of ICU patients. We support the systematic use of EHCT in critically ill, mainly hemato-oncological patients with nonspecific neurological dysfunction, as it may lead to early identification of intracranial complications.

Biomarkers Facilitate the Assessment of Prognosis in Critically Ill Patients with Primary Brain Injury: A Cohort Study

Primary injuries to the brain are common causes of hospitalization of patients in intensive care units (ICU). The Acute Physiology and Chronic Health Evaluation (APACHE) II scoring system is widely used for prognostication among critically ill subjects. Biomarkers help to monitor the severity of neurological status. This study aimed to identify the best biomarker, along with APACHE II score, in mortality prediction among patients admitted to the ICU with the primary brain injury. This cohort study covered 58 patients. APACHE II scores were assessed 24 h post ICU admission. The concentrations of six biomarkers were determined, including the C-reactive protein (CRP), the S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE), neutrophil gelatinase-associated lipocalin (NGAL), matrix metalloproteinase 9 (MMP-9), and tissue inhibitor of metalloproteinase 1 (TIMP-1), using commercially available ELISA kits. The biomarkers were specifically chosen for this study due to their established connection to the pathophysiology of brain injury. In-hospital mortality was the outcome. Median APACHE II was 18 (IQR 13–22). Mortality reached 40%. Median concentrations of the CRP, NGAL, S100B, and NSE were significantly higher in deceased patients. S100B (AUC = 0.854), NGAL (AUC = 0.833), NSE (AUC = 0.777), and APACHE II (AUC = 0.766) were the best independent predictors of mortality. Combination of APACHE II with S100B, NSE, NGAL, and CRP increased the diagnostic accuracy of mortality prediction. MMP and TIMP-1 were impractical in prognostication, even after adjustment for APACHE II score. S100B protein and NSE seem to be the best predictors of compromised outcome among critically ill patients with primary brain injuries and should be assessed along with the APACHE II calculation after ICU admission.

Diagnostic Yield and Outcomes of Computed Tomography of the Head in Critically Ill Nontrauma Patients

BACKGROUND

Computed tomography of the head (HCT) is a widely used diagnostic tool, especially for emergency and trauma patients. However, the diagnostic yield and outcomes of HCT for patients on medical intensive care units (MICUs) are largely unknown.

METHODS

We retrospectively evaluated all head CTs from patients admitted to a single-center MICU during a 5-year period for CT indications, diagnostic yield, and therapeutic consequences. Uni- and multivariate analyses for the evaluation of risk factors for positive head CT were conducted.

RESULTS

Six hundred ninety (18.8%) of all patients during a 5-year period underwent HCT; 78.7% had negative CT results, while 21.3% of all patients had at least 1 new pathological finding. The main indication for acquiring CT scan of the head was an altered mental state (AMS) in 23.5%, followed by a new focal neurology in 20.7% and an inadequate wake up after stopping sedation in 14.9% of all patients. The most common new finding was intracerebral bleeding in 6.4%. In 6.7%, the CT scan itself led to a change of therapy of any kind. Admission after resuscitation or a new focal neurology were independent predictors of a positive CT. Psychic alteration and AMS were both independent predictors of a higher chance of a negative head CT. Positive HCT during MICU is an independent predictor of lower survival.

CONCLUSIONS

New onset of focal neurologic deficit seems to be a good predictor for a positive CT, while AMS and psychic alterations seem to be very poor predictors. A positive head CT is an independent predictor of death for MICU patients.

Altered Mental Status in ICU Patients: Diagnostic Yield of Noncontrast Head CT for Abnormal and Communicable Findings

OBJECTIVE

To evaluate the diagnostic yield of noncontrast head CT for acute communicable findings in ICU patients specifically scanned for altered mental status.

DESIGN

Retrospective observational cohort study.

SETTING

University Hospital Neuroscience, Medical, and Surgical ICUs.

PATIENTS

ICU patients with new-onset altered mental status.

INTERVENTION

Noncontrast head CT.

MEASUREMENTS AND MAIN RESULTS

Reports on head CTs from two university hospitals performed for the sole indication of altered mental status in ICU patients between July 2011 and June 2013 were reviewed for 1) acute (new or worsening) hemorrhage, 2) mass effect/herniation, 3) infarction, and 4) hydrocephalus. Subgroup analyses of positive findings were performed by 1) ICU group type, 2) age, and 3) race. A total of 2,486 head CTs were performed in 1,357 patients whose age ranged from 14 to 116 years (median, 59; mean, 57.6 ± 16). Acute communicable findings in at least one of four categories were present in 22.8% (566/2,486) of examinations, with hydrocephalus being most common (11.5% [286/2,486]). The frequency of any acute communicable findings in neuroscience, medical, and surgical ICUs was 28.6% (471/1,648), 9.8% (43/440), and 13.1% (52/398), respectively. Neuroscience ICU head CTs had significantly higher rates of acute communicable findings in all categories, except for acute infarction, compared with the other two ICUs (p < 0.001). Acute hydrocephalus (13.6% vs 7.4%; p < 0.001) and mass effect (6.7% vs 4.3%; p = 0.01) were more common in patients less than 65 years. For other acute categories, no significant difference was noted by age. There was no significant difference in the likelihood of a positive examination by race.

CONCLUSIONS

Almost one in four head CTs in a university ICU patient population performed for primary indication of altered mental status yields abnormal communicable findings. In this patient population, utilization management barriers to examination ordering should be minimized.

Low likelihood of intracranial hemorrhage in patients with cirrhosis and altered mental status

BACKGROUND & AIMS

Given the myriad causes of altered mental status (AMS), patients with cirrhosis and hepatic encephalopathy often present a diagnostic dilemma. In light of the perceived bleeding tendency of patients with cirrhosis, intracranial hemorrhage (ICH) is often feared, so these patients frequently undergo non-contrast computed tomography (CT) of the head. However, little is known about the diagnostic yield of CT for patients with cirrhosis presenting with AMS.

METHODS

We analyzed all unique admissions of patients with cirrhosis who underwent head CT from 2003 through 2013 (N = 462) at the Beth Israel Deaconess Medical Center in Boston. By using blinded reviewers, we coded the indications and results of the CT scans separately and evaluated patient characteristics associated with acute findings.

RESULTS

A higher proportion of patients who presented with falls or trauma, focal neurologic signs, or history of ICH were found to have ICH (13 of 146, 8.9%) than of patients who presented with AMS, headache, or fever (1 of 316, 0.3%; P < .0001). The odds ratio of ICH in patients with low-risk indications was 0.02 (95% confidence interval, 0.001-0.14). The number needed to scan (NNS) for each positive result from CT varied by indication: focal neurologic deficits (NNS = 9), fall/trauma (NNS = 20), and AMS (NNS = 293). There was no association between presence of new, acute ICH and platelet count, international normalized ratio, level of creatinine, or Model for End-Stage Liver Disease score.

CONCLUSIONS

Despite abnormal hemostatic indices, patients with cirrhosis presenting with AMS in the absence of focal neurologic deficits or trauma have a low likelihood of ICH.

Frequency of acute changes found on head computed tomographies in critically ill patients: a retrospective cohort study

PURPOSE

The frequency of positive findings on computed tomography (CT) of the head in critically ill patients who develop neurologic dysfunction is not known.

MATERIALS AND METHODS

Cohort study of head CTs for patients admitted to 3 intensive care units from 2005 to 2010. We documented the frequency of acute changes for all head CTs and for the subgroup of patients with altered mental status (AMS). We also examined associations between patient characteristics or medications administered before head CT and the odds of an acute change on head CT using multivariate logistic regression.

RESULTS

During 11 338 intensive care unit admissions, there were 901 eligible head CTs on 706 patients (6% of patients). Among head CTs, 155 (17.2%) assessed concern of new focal deficit, 99 (11.0%) concern for a seizure, and 635 (70.5%) for AMS. Acute changes were found on 109 (12.1%; 95% confidence interval [CI], 10.0%-14.2%) of all head CTs, and 30% (22.4%-36.9%) of patients with focal deficits, 16.2% (8.8%-23.5%) of patients with seizures but only 7.4% (5.4%-9.4%) for patients with AMS. A diagnosis of sepsis was associated with a decreased odds of an acute change on head CT for all head CTs (odds ratio 0.61; 95% CI, 0.40-0.95; P = .028) but was not significantly associated with a decreased risk among the cohort of head CTs for AMS (odds ratio 0.82; 95% CI, 0.41-1.62; P = .56). No other factors were associated with an altered risk of acute change on head CT for all patients in our cohort or for those with AMS.

CONCLUSIONS

Acute changes on head CTs performed for concern regarding new focal neurologic deficit or seizures are frequent compared with those performed for AMS with a nonfocal examination. No specific patient characteristics or medications were associated with a large change in the likelihood of finding an acute change for patients with AMS.

Brain computer tomography in critically ill patients--a prospective cohort study

Background

Brain computer tomography (brain CT) is an important imaging tool in patients with intracranial disorders. In ICU patients, a brain CT implies an intrahospital transport which has inherent risks. The proceeds and consequences of a brain CT in a critically ill patient should outweigh these risks. The aim of this study was to critically evaluate the diagnostic and therapeutic yield of brain CT in ICU patients.

Methods

In a prospective observational study data were collected during one year on the reasons to request a brain CT, expected abnormalities, abnormalities found by the radiologist and consequences for treatment. An “expected abnormality” was any finding that had been predicted by the physician requesting the brain CT. A brain CT was “diagnostically positive”, if the abnormality found was new or if an already known abnormality was increased. It was “diagnostically negative” if an already known abnormality was unchanged or if an expected abnormality was not found. The treatment consequences of the brain CT, were registered as “treatment as planned”, “treatment changed, not as planned”, “treatment unchanged”.

Results

Data of 225 brain CT in 175 patients were analyzed. In 115 (51%) brain CT the abnormalities found were new or increased known abnormalities. 115 (51%) brain CT were found to be diagnostically positive. In the medical group 29 (39%) of brain CT were positive, in the surgical group 86 (57%), p 0.01. After a positive brain CT, in which the expected abnormalities were found, treatment was changed as planned in 33%, and in 19% treatment was changed otherwise than planned.

Conclusions

The results of this study show that the diagnostic and therapeutic yield of brain CT in critically ill patients is moderate. The development of guidelines regarding the decision rules for performing a brain CT in ICU patients is needed.

Metabolic encephalopathies in the critical care unit

PURPOSE OF REVIEW

This article summarizes the most common etiologies and approaches to management of metabolic encephalopathy.

RECENT FINDINGS

Metabolic encephalopathy is a frequent occurrence in the intensive care unit setting. Common etiologies include hepatic failure, renal failure, sepsis, electrolyte disarray, and Wernicke encephalopathy. Current treatment paradigms typically focus on supportive care and management of the underlying etiology. Directed therapies that target neurochemical and neurotransmitter pathways that mediate encephalopathy are not currently available and represent an important area for future research. Although commonly thought of as reversible neurologic insults, delirium and encephalopathy have been associated with increased mortality, prolonged length of stay and hospital complications, and worse long-term cognitive and functional outcomes.

SUMMARY

Recognition and treatment of encephalopathy is critical to improving outcomes in critically ill patients.

Delirium and sedation in the ICU

Delirium is defined by a fluctuating level of attentiveness and has been associated with increased ICU mortality and poor cognitive outcomes in both general ICU and neurocritical care populations. Sedation use in the ICU can contribute to delirium. Limiting ICU sedation allows for the diagnosis of underlying acute neurological insults associated with delirium and leads to shorter mechanical ventilation time, shorter length of stay, and improved 1 year mortality rates. Identifying the underlying etiology of delirium is critical to developing treatment paradigms.